Managing Plant Microbe Interactions for the Management of Soil ...

CENTRE OF ADVANCED FACULTY TRAINING 

IN PLANT PATHOLOGY 

(Indian Council of Agricultural Research, New Delhi) 

Proceedings of the 27 th Training 

on 

“Managing Plant Microbe Interactions for the Management 

of Soil-borne Plant Pathogens” 

January 22 to Februady 11, 2013 

Dr.. Karuna Viishunavatt,, Diirecttor,, CAFT 

Dr.. Yogendra Siingh,, Course Coordiinattor 

Dr.. R..P.. Siingh,, Co--course Coordiinattor 

G.B. Pant University of Agriculture and Technology 

Pantnagar- 263 145 (Uttarakhand)

PREFACE 

Plants are constantly exposed to a wide range of fungal, bacterial and viral pathogens and globally, 

enormous losses of the crops are caused by plant diseases. While no overall estimation of the loss caused by 

soil borne plant diseases in India has been made, it must be considerable and varying from crop to crop. 

The future of sustainable agriculture in India will increasingly rely on the integration of biotechnology with 

traditional agricultural practices. Although genetic engineering promises enhanced yields and disease 

resistance, it is also important to recognize that plants exist in intimate associations with microorganisms, 

some of which cause plant disease while others protect against disease. Understanding plant microbe 

interactions, identifying and utilizing microorganisms or microbial products to control plant disease and 

enhance crop production are integral parts of sustainable agriculture. 

In view of above, the 21 day training under Center of Advanced Faculty Training in Plant Pathology 

was designed to give an updated information/knowledge on “Managing Plant Microbe Interactions for the 

Management of Soil-borne Plant pathogens” to the participants, so that they can deal with the opportunity 

and applicability of emerging technologies for enhancing the agricultural productivity. Excellent response 

was received from all over India for participation in this training. Twenty five participants representing 

twelve states, who actively participated in the programme, were exposed to the recent advances made 

towards various aspects of plant microbe interactions through series of lectures, practicals and field visits. 

We are grateful to the ICAR for sponsoring this 27 th advanced training programme in series, and 6 th under 

the banner of the newly created Centre of Advanced Faculty Training in Plant Pathology at Pantnagar. We 

are highly grateful to Shri. Subhash Kumar, IAS, Vice-Chancellor for his constant support, guidance and 

encouragement in making the training a great success. We are highly obliged to Dr. J. Kumar, Dean 

Agriculture for his keen interest, unending support and guidance received during the course of the training 

programme. We like to put on record the help and guidance received from All the Deans and Directors in 

the successful conduct of training programme. We sincerely acknowledge the services of our guest speakers 

Dr. Serge Savary, Director of Research, Phytopathologist, INRA, France; Dr. L. Willocquet, In-charge of 

Research, Phytopathologist, INRA, France; 

Dr. U.S. Singh, Sought-East Asia Coordinator, IRRI, New 

Delhi; Dr. R.K. Khetarpal, Science Director (Asia) and Country Director (India), CABI; Dr. Rakesh 

Pandey, Scientist, Central Institute of Medicinal &Aromatic Plants and Dr. Y.P. Singh, Principal Scientist, 

Forest Pathology Division, Forest Research Institute, Dehradun. We would like to place on record the help 

and logistic support received from Dr. Anjuli Agarwal, Officer In-charge, Majhera Research Station and her 

team and also for delivering lecture during exposure visit of participants. Several scientists from various 

departments such as Farm Mach.& Power Engineering; Microbiology; Biological Sciences; Molecular 

Biology and Genetic Engineering; Soil Science; Veterinary Anatomy; Agronomy; Agrometerology; 

KNSCCF and the University library in addition to the Plant Pathology rendered all possible help and 

delivered scientific lectures and designed practical exposure to the participants. We acknowledge their 

contributions with utmost gratitude and sincerity. 

. 

Dr. R.P. Singh Dr. Yogendra Singh Dr. K. Vishunavat 

Co-course Coordinator Course Coordinator Director, CAFT 

Pantnagar 

February 11, 2013

CONTENTS 

Sl. No. Title Speaker Page 

Welcome Address Dr. K. Vishunavat i-iii 

1. Department of Plant Pathology Dr. K. Vishunavat 1-24 

2. Management of Pests in Protected Cultivation- Dr. H.S. Tripathi 25-29 

Problems & Perspectives 

3. Soil Solarization for Biocontrol of Plant Pathogens Dr. Yogendra Singh 30-37 

4. Microbial Interactions in Phyllosphere and Dr. P.C. Srivastava 38-44 

Rhizosphere 

5. Exploiting Nematophagus Fungi for the Dr. Rakesh Pandey 45-46 

Management of Root-Knot Nematodes 

6. Soil Fertility in Organic Farming System Dr. D.K. Singh 47-56 

7. The Role of Soil Microfauna in Maintaining Soil Dr. Navneet Pareek 57-60 

Health 

8. Soil Degradation- A Threat to Sustainable Dr. Ramesh Chandra 61-66 

Agriculture 

9. Role of Plant Growth Promoting Rhizobacteria in Dr. Anita Sharma 67-72 

Crop Improvement 

10. Implication of PGPR for Rhizospheric Colonization Dr. Reeta Goel 73-74 

and Plant Growth Promotion 

11. Microbes and Intellectual Property Rights Dr. H.S. Chawla 75-79 

12. Induced Resistance: A Novel Strategy for Plant Dr. P.K. Shrotria 80-88 

Protection against Diseases 

13. Characterization of Macro- and Meteorological Dr. H.S. Kushwaha 89-97 

Variables for Disease Management 

14. Role of Organic Amendments in the Management Dr. R.P. Singh 98-101 

of Soil Borne Plant Pathogens 

15. Evaluation and Selection of Promising Trichoderma Dr. A.K. Tewari 102-105 

Isolates for the Management of Soil Borne Fungal 

Plant Pathogens 

16. Biodeterioration of Seed in Storage and its Control Dr. K. Vishunavat 106-115 

by Microbial Antagonists 

17. Reduced Risk Pesticides: The Best Alternative to Dr. S.N. Tewari 116-122 

Ensure Food Safety without Compromising 

Environment Quality 

18. Trichoderma as Inducer of Plant Resistance to Dr. R.P. Singh 123-128 

Diseases 

19. Influence of Environmental Parameters on Dr. A.K. Tewari 129-130 

Trichoderma Strains with Biocontrol Potentials 

-i-

20. Smut Fungi: Potential Pathogens and Biocontrol Dr. K. Vishunavat 131-135 

Agents 

21. Biocontrol of Fungal Phytopathogens by Dr. Lakshmi Tewari 136-140 

Trichoderma spp. 

22. Biological Control of Plant Diseases under Different Dr. V.S. Pundhir 141-146 

Environments 

23. Microbes and Soil Quality Dr. K.P. Raverkar 147-155 

24. Suppressive Soils in Plant Disease Management Dr. K.P. Singh 156-164 

25. Pesticides: Past, Present and Future R.P. Srivastava 165-176 

26. Isolation, Identification and Quantification of Dr. Roopali Sharma 177-179 

Trichoderma 

27. Mechanism of Mycoparasitism and Antibiosis Dr. Roopali Sharma 180-183 

28. Mass Production and Formulation Technology of Dr. Roopali Sharma 184 

Trichoderma 

29. Identification of Pseudomonas and Bacillus isolates Dr. J. Kumar 185-187 

using Biolog System 

30. Biochemical Tests for Identification of Bacterial Dr. Yogendra Singh 188-191 

Pathogens 

31. Visit to Meteorological Observatory and Automatic Dr. H.S. Kushwaha 192-197 

Weather Station in Cropped Field at N.E.B. CRC 

--- i 

Annexure- I (Committee members) 

Annexure- II (List of Participants) 

Annexure- III (List of Speakers) 

Annexure- IV (Training Course Schedule) 

--- i-iii 

--- i-ii 

--- i-iv 

-ii-

WELCOME ADDRESS 

by 

Dr. K. Vishunavat 

Director CAFT 

Prof. & Head, Plant Pathology, College of Agriculture 

G.B. Pant University of Agriculture & Technology, Pantnagar- 263 145 

on 

January 22, 2013 

Good morning and welcome to the 

Inaugural Session of the 27 th CAFT training on 

“Managing Plant Microbe Interaction for 

Management of Soil -borne Plant Pathogens”. 

Dr. J.P. Singh, 

Director Experiment 

Station, Dr. Y.V Singh , acting Dean Agriculture 

,Dr. Y Singh, Course Coordinator of the present 

training, Deans and Directors, Jt. Directors, 

Officers, Heads of Departments, Senior faculty 

members, Colleagues, Staff members, 

the 

trainees from different universities, Students, Press 

& Media, Ladies & Gentle men. 

It is indeed a pleasure in welcoming the, Dr 

J.P. Singh, Director Experiment Station and Chief 

Guest of the function who has consented to grace 

the occasion despite at a very short notice. We all 

are all very thankful to you. 

I am also pleased in welcoming Dr. Y.B 

Singh, acting Dean, College of Agriculture who 

readily agreed to grace the occasion. 

I would also like to welcome Dr. S.C. 

Saxena, a honourary faculty in the college of 

agriculture. 

I welcome Dean, College of technology Jt. 

Director Research Dr. Ramesh Chandra who are 

present here in the hall and have spared their 

valuable time to grace this occasion. 

I also extend the warm welcome to all The 

Heads and faculty members of various 

departments who have also responded to our 

invitation. I welcome all of you to the function. 

I extend the special welcome to the 

participants of the training programme from 

different universities who have traveled a long 

distance to reach Pantnagar. 

I welcome you all 

and assure you a comfortable stay within our 

means. 

I also welcome all staff members, students, 

press and media and others who are present in the 

hall and have made the arrangements for this 

inaugural session. 

Ladies and gentlemen, Department of 

Plant Pathology came into existence and 

accredited by ICAR as early as in 1961 just a year 

after the foundation of the university in 1960. 

The department has a bequest of having 

legendaries like Drs. Y.L. Nene and R.S Singh who 

have laid the foundation of strong commitment to, 

sound education, research and extension in Plant 

Pathology at Pantnagar. Dr. Y.L. Nene, first head 

of the department of plant pathology, and a FAO 

award recipient for his out standing contribution for 

the management of khaira disease and Dr. Singh, 

a prolific writer who has written 9 books in the field 

of Plant pathology. His book “Plant Diseases” has 

its 9th edition and is known as “Geeta” in plant 

pathology. Under the capable leadership, of these 

great plant pathologists, department expanded to 

include many dedicated faculty members whose 

contributions made the department a recognized 

leader in the area of plant pathology in the country. 

With this sound background, the next 

generation is also attentively keeping pace with the 

changes evolved in the modern agriculture and are 

focused to work on the thrust area of plant 

pathology. 

At present the department includes 08 

professors, one honorary professor from INRA, 

France, 06 Associate Professors and 06 Assistant 

Professors with 18 technical and 5 supporting 

-i-

staffs. The entire fraternity of plant pathology is 

committed for Department’s education, research 

and extension programme. 

The department has a well-knit under 

graduate (U.G.) and post graduate (P.G.) 

programme with updated course curricula. It offers 

six U.G. and thirty six P.G. courses. The great 

diversity of areas of expertise and interests present 

in the Department leads to diversity in thesis titles. 

So far almost 335 M.Sc. and 198 Ph.D. students 

have earned degrees from the Department. 

The department is actively engaged in the 

research work on both fundamental and applied 

aspects in the domains of ecology of soil borne 

plant pathogens, epidemiology and forecasting, 

biological control and IPM, molecular diagnostics, 

pathogen population biology, disease resistance, 

seed pathology, fungicides, nematology, 

phytovirology, phytobacteriology and biology & 

technology of mushroom production. 

The distinguished faculty of the department 

has brought in a number of national and 

international research grants besides a series of 

AICRPs. For a number of AICRPs such as those of 

Oilseeds, Potato, Seeds, and maize, the faculty 

members of the department render services as the 

Project Coordinators also. 

Individual staff members with in the 

department have long been recognized for their 

leadership role in the science of Plant Pathology. 

By way of their significant contributions, faculty 

members of this department have been assigned 

to work at national level. Many of the faculty 

members have earned International positions. 

Also a number of faculty members have served as 

president, vice presidents, and zonal president of 

several professional societies. 

Over the years, the plant pathology faculty 

members and students have won over 40 national 

and international awards. 

The Department has a unique 

distinction of producing 60 books, both in Hindi and 

English published not only by Indian but also 

reputed international publishers, besides a series 

of technical bulletins, working sheets, lab manuals, 

compendia and extension literature. 

The Department has a molecular and 

referral lab for quality evaluation of biocontrol 

agents notified by central insecticide board in 

respect to bio-pesticides. Similarly, the Department 

also holds strength in mushroom research and 

trainings. 

The contributions made towards teaching, 

research and extension by the department is 

recognized by ICAR and in 1995, ICAR upgraded 

the department to the status of CAS in Plant 

Pathology and subsequently to CAFT in 2009 with 

the major mandate to train scientific faculty from all 

over the country in important and innovative areas 

of Plant Pathology. So far 26 trainings have been 

conducted and 534 scientists from 25 states have 

participated. 

The topic of the present training “Managing 

Plant Microbe Interactions for the Management of 

Soil-borne Plant Pathogens” under CAFT is well 

thought of in the present agriculture scenario 

where the cost of soil borne plant pathogens to 

society and the environment far exceeds the direct 

costs to growers and consumers. The use of 

chemical pesticides to control soil borne pathogens 

has caused significant changes in air and water 

quality, altered natural ecosystems resulting in 

direct and indirect affects on wildlife, and caused 

human health problems. 

Yield failures due to acute soil borne 

diseases such, vascular wilts, take-all disease in 

cereals, root rots, scab and nematode diseases 

have been even more severe and at times may 

even destroy entire agriculture industries. 

Soil borne plant pathogens are complex 

not only in their behavioral pattern but also in their 

biochemical constituents. It becomes still complex 

when soil microbial inhabitants interact with these 

plant pathogens. The level of this interaction is also 

influenced by soil conditions such as soil structure, 

pH, moisture, oxygen, nutrients, cropping pattern, 

and other intrinsic factors which affect the growth 

and activity of the non-pathogenic organisms. 

Consequently, whenever the soil environment 

changes, there is potential for either a positive or 

negative influence on soil-borne plant pathogens. 

-ii-

Hence, it is not very easy to control these 

pathogens. Understanding and dealing with soil 

borne pathogens is a very difficult and challenging 

task. 

A natural soil system is a reservoir of 

millions of microorganisms which constantly 

communicate with each other and maintain life's 

processes in an orderly way. The management of 

plant pathogens by naturally occurring 

microorganisms in an agro-ecosystem has existed 

long before as the crop cultivation started. There 

are many diverse groups of microorganisms in soil. 

Soil microbial diversity confers protection against 

soil borne plant diseases. However, in practice, the 

ground reality is very different. The health status of 

the soil is constantly under threat due to the 

repeated use of chemicals and crop cultivation 

patterns which ultimately reduce the immunity of 

the plants towards diseases. The population of 

pathogens when multiply beyond the thresh hold 

level create macro imbalances resulting in disease 

development and loss of productivity. An 

understanding of the interactions which occur 

among different groups of soil flora and fauna may 

help to manipulate them in a manner which 

achieves favorable effects on plant growth. 

At the time when there is growing demand 

to do away with chemical, due to many problems 

such as pests developing resistance, resurgence 

of once minor pest into a major problem, 

environmental and food safety hazards, and an 

adverse effects on the non target organisms (such 

as pollinators, parasitoids, predators and wild 

animals), Identifying, understanding and utilizing 

microorganisms or microbial products to control 

plant disease and enhance crop production are 

becoming more central parts of sustainable 

agriculture. 

Biologically-based pest management offers 

potential management of soil borne disesase while 

causing no or minimal detrimental environmental 

impact. Biological control practices need an 

integrative approach, and more knowledge than 

chemical control. Some of the benefits of utilizing 

microorganisms include: reduced dependence on 

chemical pesticides, lack of development of 

pathogen resistance to biological control 

organisms, more selective action against 

pathogens and not against beneficial organisms; 

biodegradability of microbial pesticides and their 

by-products; reduced danger to humans or 

animals; improvement of soil quality and health; 

increased food safety; long term solutions for 

management of soil-borne pathogens; and 

management of plant diseases in natural 

ecosystems. 

Bioagents can be introduced in an attempt 

to control diseases. This can be done by way of 

organic amendments that stimulate the naturally 

occurring antagonists or by integrating microbial 

populations by way of natural organic fertilizers 

with microbial supplements. In both cases, the 

products are applied prior to disease development 

as they are preventive and not curative. 

Biological control of soil borne plant 

pathogens is though a slow and deliberate 

process, but the results are more stable, consistent 

and lasting compared to the chemical control. 

However, issues such as method of application, 

formulation of biocontrol microorganisms and 

timing of application need to be given emphasis. 

Though, the complexity of plant–soil– 

microbial interactions is so varied, that a complete 

understanding of all the relationships involved is 

unlikely to be achieved. Nevertheless, the 

consequences of beneficial biological interactions 

that stimulate crop yields and improve plant health 

can be evaluated relatively simply and a number of 

general management strategies can be devised, 

accordingly. 

I will not go much into the details about the 

topic because it would be introduced to more 

elaborately by Dr. J.P. Singh, Chief Guest of the 

function. 

With these words I welcome you all and 

assure a fruitful and comfortable stay to the 

participants of this 27th training programme of 

CAFT in Plant Pathology. 

Thank you very much! 

* * * * * * * * * 

-iii-

(Managing Plant Microbe Interactions for the Management of Soil-borne Plant Pathogens) 

DEPARTMENT OF PLANT PATHOLOGY 

Establishment of University – 1960 

Department created and Accredited – 1961 

M. Sc. (Ag) Programme – 1963 

Ph. D. Programme – 1965 

Courses 

Staff position 

Ist course – Introductory Plant Pathology 

Ist Instructor – Dr. Y. L. Nene 

Ist HOD – Dr. Y. L. Nene 

06 UG courses 

37 PG courses 

08 Professor 

02 Honorary Professor 

06 Associate Professor 

06 Assistant Professor 

01 Subject Matter Specialist 

18 Technical staff 

05 Supporting staff 

The G.B. Pant University of Agriculture & Technology (earlier known as U.P. Agriculture 

University) was established in 1960. Department of Plant pathology was created and accredited by ICAR 

in 1961. The postgraduate degree programme leading to M.Sc. (Ag.) Plant Pathology and Ph.D. Plant 

Pathology were started in 1963 and 1965, respectively. 

Faculty of Plant Pathology is highly qualified and includes 08 professors, 02 Honorary Professor, 

06 Associate Professor, 06 Assistant Professor and 01 Subject Matter Specialist with 18 technical staff 

and 05 supporting staffs. 

Sl. No. Name of Faculty members Designation Area of specialization 

1 Dr. (Mrs. ) Karuna 

Vishunavat 

Prof.&Head-cum- 

Director, CAFT 

2 Dr. J. Kumar Professor & Dean 

Agriculture 

Seed Pathology 

Plant disease management 

on small farm, IPM, Biological 

control, Pathogen population 

biology. 

3 Dr. R.P. Awasthi Professor Oilseed crop diseases 

4 Dr. K.S. Dubey Professor Soybean diseases 

- 1 -


5 Dr. V.S. Pundhir Professor Potato Pathology & 

Epidemiology of Crop Disease 

6 Dr. Pradeep Kumar Professor Maize Pathology & Fruit 

Pathology 

7 Dr. R.K. Sahu Professor Sugarcane Pathology 

8 Dr. K.P. Singh Professor Epidemiology & Management 

of Pulse Diseases 

9 Dr. S.C. Saxena Honorary Professor Maize Pathology 

10 Dr. Sergey Savary Honorary Professor Epidemiology 

11 Dr. Vishwanath Associate Professor Soybean Pathology & 

Rapeseed Mustard diseases 

12 Dr. Yogendra Singh Senior Research 

Officer 

13 Dr. R.P. Singh Senior Research 

Officer 

14 Dr. K.P.S. Kushwaha Senior Research 

Officer 

15 Dr. A.K. Tewari Senior Research 

Officer 

Sorghum diseases 

16 Dr. Satya Kumar Associate Professor Nematology 

17 Dr. L.B. Yadav Assistant Professor Mycology 

Microbial ecology, fungicides 

& Vegetable Pathology 

Pulse Pathology, Mycology 

(Mushroom) 

Oilseed crops diseases & Biocontrol 

18 Dr. (Mrs.) Roopali Sharma Junior Research 

Officer 

19 Dr. Bijendra Kumar Junior Research 

Officer 

20 Dr. S.K. Mishra Junior Research 

Officer 

21 Dr. (Mrs.) Deepshikha Junior Research 

Officer 

22 Dr. (Mrs.) Geeta Sharma Junior Research 

Offcer 

23 Dr. (Mrs.) N. W. Zaidi Subject Matter 

Specialist (on EOL) 

Biological control, IPM 

Technology 

Small Millets Pathology 

Mushroom Biotechnology and 

Mushroom Biology 

Wheat diseases 

Mushroom Breeding, its 

Diseases & spawn production 

Biological control of plant 

disease & IPM 

TEACHING 

The department of plant pathology has made immense contribution in the area of teaching, 

research and extension. A well-knit UG and PG programme with updated and modern syllabi is 

already in operation in the department. The department offers 6 courses for undergraduate 

students. There are 37 postgraduate courses leading to M.Sc. (Ag.) and Ph.D. degrees in Plant 

Pathology. Since the inception of the department 335 M.Sc. (Ag.) and 198 Ph.D. students have 

- 2 -

een awarded degrees. 

Under graduate courses 


Sl. No. Course N0. Course name Credit 

1. APP-312 Introductory Plant Pathology 3(2-0-3) 

2. APP-314 Crop Diseases & their Management 2(1-0-3) 

3. APP-330 Diseases of Fruit and Vegetable Crops 2(1-0-3) 

4 APP/APE-322 Integrated Pest & Disease Management 2(1-0-3) 

5. APP-381 Mushroom Cultivation 1(0-0-1x2) 

6. APP-382 Biological Control of Plant Pathogens 2(0-0-2x2) 

Post graduate courses 

Sl. No. Course No. Course name Credit 

1. APP-401 Introductory Plant Pathology 3(2-0-1) 

2. APP-410 Diseases of Field Crops 3(2-0-1) 

3. APP-430 Diseases of Horticultural Crops 3(2-0-1) 

4 APP-507 Disease of Field and Medicinal Plants 3(2-0-1) 

5. APP-508 Disease of Fruits, and Ornamental Crops 3(2-0-1) 

6. APP-509 Disease of Vegetable and Spice Crops 3(2-0-1) 

7. APP/ENT- 514 Insects Vector of Plant Viruses and other 2(1-0-1) 

Pathogens 

8. APP-515 Biological Control of Plant Diseases 3(2-0-1) 

9. APP-516 Integrated Disease Management 3(2-0-1) 

10. APP-517 Mushroom Production Technology 3(2-0-1) 

11. APP-519 Post Harvest Diseases 3(2-0-1) 

12. APP/ENT-520 Plant Quarantine 2(2-0-0) 

13. BBB-599 Mycology 3(2-0-1) 

14. APP-600 Master’s Seminar 1(0-0-1) 

15. APP-601 Special Problem 1 

16. APP-602 Plant Virology 3(2-0-1) 

17. APP-603 Plant Bacteriology 3(2-0-1) 

18. APP-604 Principles of Plant Pathology 3(3-0-0) 

19. APP-606 Principles of Plant Disease Management 3(2-0-1) 

20. APP-607 Plant Biosecurity and Biosafety 2(2-0-0) 

21. APP-611 Chemicals in Plant Disease Management 3(2-0-1) 

22. BBB-615 Advanced Mycology 3(2-0-1) 

23. APP-616 Advanced Plant Virology 3(2-0-1) 

24. APP-617 Advanced Bacteriology 3(2-0-1) 

25. APP-618 Principles and Procedures of Certification 1(1-0-0) 

26. APP-622 Techniques in Phytonematology 1(0-0-1) 

27. APP-624 Cultural & Chemical Control of Plant Parasitic 2(1-0-1) 

Nematodes 

28. APP-630 Phytonematology 2(1-0-1) 

29. APP-690 Master’s Thesis Research 20 

30. APP-704 Molecular Basis of Host Pathogen Interaction 3(2-0-1) 

31. APP-710 Seed Health Technology 3(2-0-1) 

32. APP-712 Ecology of Soilborne Plant Pathogens 3(2-0-1) 

33. APP-713 Disease Resistance in Plants 2(2-0-0) 

34. APP-718 Epidemiology and Forecasting of Plant 3(2-0-1) 

Diseases 

35. APP-788 Doctoral Seminar I 1(0-0-1) 

- 3 -


36. APP-789 Doctoral Seminar II 1(0-0-1) 

37. APP-790 Ph.D. Thesis Research 45 

Books Published 

The department has unique distinction of producing 33 books published by not only Indian 

but also reputed international publishers like Elsevier Science (UK), Gordon and Beach (UK), 

Prentice Hall (USA), CRC Press (USA), Science Publisher (USA), Lewis Publishers (USA) etc. 

The Department has produced 17 text books in Hindi and has also published 13 technical 

bulletins. The faculty members have written/prepared several laboratory manuals, reference 

books, working sheets on diseases, bulletins, extension pamphlets, etc. for the benefit of U.G. and 

P.G. students of plant pathology as well as for the farmers. 

• Plant Disease 8 th Edition by R.S. Singh 

• An Introduction to Principles of Plant Pathology 4 th Edition by R.S. Singh 

• Plant Pathogens: The Fungi by R.S. Singh 

• Plant Pathogens: The Viruses & Viroids by R.S. Singh 

• Plant Pathogens: The Prokaryotes by R.S. Singh 

• Integrated Disease Management by R.S. Singh 

• Diseases of Fruit Crops by R.S. Singh 

• Fungicides in Plant Disease Control by P.N. Thapliyal and Y.L. Nene 

• Diseases of Annual Edible Oilseed Crops Vol.-I by S.J. Kolte 

• Diseases of Annual Edible Oilseed Crops Vol.-II by S.J. Kolte 

• Diseases of Annual Edible Oilseed Crops Vol.-III by S.J. Kolte 

• Diseases of Linseed & Fibre Flex by S.J. Kolte 

• Castor Diseases & Crop Improvement by S.J. Kolte 

• Plant Diseases of International Importance Vol.I: Diseases of Cereals & Pulses by 

U.S. Singh, A. N. Mukhopadhyay, J. Kumar, and H.S. Chaube 

• Plant Diseases of International Importance Vol.II: Diseases of Vegetables & Oil Seed 

Crops by H.S. Chaube, U.S. Singh, A. N. Mukhopadhyay & J. Kumar 

• Plant Diseases of International Importance Vol.III: Diseases of Fruit Crops by Drs. J. 

Kumar, H.S. Chaube, U. S. Singh & A. N. Mukhopadhyay 

• Plant Diseases of International Importance Vol.IV: Diseases of Sugar, Forest & 

Plantation Crops A. N. Mukhopadhyay, J. Kumar, H.S. Chaube & U.S. Singh 

• Pathogenesis & Host Specificity in Plant Diseases Vol.I: Prokaryotes by U. S. Singh, 

Keisuke Kohmoto and R. P. Singh 

• Pathogenesis & Host Specificity in Plant Diseases Vol. II: Eukaryotes by Keisuke 

Kohmoto, U.S. Singh and R. P. Singh 

• Pathogenesis & Host Specificity in Plant Diseases Vol. III: Viruses & Viroids by R. P. 

Singh, U.S. Singh and Keisuke Kohmoto. 

- 4 -


• Aromatic Rices by R.K. Singh, U.S. Singh and G. S. Khush 

• A Treatise on the Scented Rices of India by R.K. Singh and U.S. Singh 

• Scented Rices of Uttar Pradesh & Uttaranchal by R. K. Singh and U.S. Singh 

• Plant Disease Management : Principles & practices by H.S. Chaube and U.S. Singh 

• Molecular Methods in Plant Pathology by R. P. Singh and U.S. Singh 

• Soil Fungicides Vol.-I by A.P. Sinha and Kishan Singh 

• Soil Fungicides Vol.-II by A.P. Sinha and Kishan Singh 

• Experimental & Conceptual Plant Pathology Vol.I: Techniques by R.S. Singh, U. S. 

Singh, W.M. Hess & D.J. Weber 

• Experimental & Conceptual Plant Pathology Vol. II: Pathogenesis and Host 

Specificity by R.S. Singh, U. S. Singh, W.M. Hess & D.J. Weber 

• Experimental & Conceptual Plant Pathology Vol.III: Defense by R.S. Singh, U. S. 

Singh, W.M. Hess & D.J. Weber 

• Seed Pathology, 2 volumes by V.K. Agarwal 

• Phytopathological Techniques by K. Vishunavat and S.J. Kolte 

• Crop Diseases & Their Management by H.S. Chaube & V.S. Pundhir 

• Seed borne diseases of crops & their management by V.K. Agrawal & Y.L. Nene 

• Plant Pathogens: the Nematodes by R.S. Singh 

• Disease of vegetables crops by R.S. Singh 

• Introductory Plant Pathology by H.S. Chaube & Ram Ji Singh 

• Seed Health Testing: Principles and Protocols by Karuna Vishunavat 

• Fundamentals of Seed Pathology by Karuna Vishunavat 

• Mushroom Production Technology by R.P. Singh & H.S. Chaube 

• The Elements of Plant Virology: Basic concepts and practical class exercises by S.J. 

Kolte & A.K. Tewari 

• A text book of Comprehensive Plant Pathology by Karuna Vishunavat and S.J. Kolte 

• Ecofriendly Innovative Approaches in Plant Disease Management by V.K. Singh, Y. 

Singh and A. Singh (2012) 

Books in Hindi 

• lfCt;ksa ds jksx& th0 ,l0 nwcs] vesfjdk flag ¼1976½ 

• Qlyksa ds jksx &,0,u0 eq[kksik/;k;] vkj0 ,0 flag ¼1976½ 

• Qyksa ds jksx& ih0 ,u0 Fkify;ky] ,l0 ih0 ,l0 csuhoky ¼1976½ 

• ikS/kksa ds jksx &vkj0 ,l0 flag ¼1976½ 

• doduk'kh ,oa ikni jksx fu;a=.k& okbZ0 ,y0 uSu (1976) 

• Qlyksa ds jksxksa dh jksdFkke& laxeyky ¼1984½ 

- 5 -


• e'k:e mRiknu rduhdh& vkj0 ih0 flag] v”kksd pkS/kjh] iznhi dqekj ¼1997½ 

• feysV ds jksx&,0 ih0 flUgk ,oa ts0 ih0 mik/;k; (1997) 

• lfCt;ksa ds jksx& ,l0 ,u0 fo”odekZ] ,p0 ,l0 pkSos ,oa ,0ih0 flUgk (2003) 

• Qyksa ds jksx & ,l0 ,u0 fo”odekZ ¼2006½ 

• lfCt;ksa ds jksxksa dh jksdFkke & ,l0 ,u0 fo'odekZ ¼2000½ 

• cht jksx foKku& oh0 ds0 vxzoky ¼1999½ 

• eDdk ds jksx& laxe yky ¼1993½ 

• /kku ds jksx & vkj0 ,0 flag ,oa ts0 lh0 HkV~V ¼1995½ 

• Qly&lCth&Qy jksx] igpku ,oa izcU/k & ;ksxsUnz flag ,oa vf[kys'k flag 

• O;ogkfjd e”k:e mRiknu & ds0ih0,l0 dq”kokgk] ds0ds0 feJk 

• lfCt;ksa ds izeq[k jksx ,oa mudk izcU/ku&“kksHkukFk fo”odekZ 

Manuals 

• Chemicals in Plant Disease Control by Y.L. Nene, R.K. Tripathi, P.N. Thapliyal & S.C. 

Saxena (1974) 

• Management of Soil Borne Plant Diseases by R.S. Singh (1980) 

• Biocontrol of Fungal Plant Disease by A.N. Mukhopadhyay, H.S. Chaube, U.S. Singh & 

S.C. Saxena (1994) 

• Identification of Plant Diseases and their Control by A. N. Tewari (2000) 

• Epidemiology in Plant Diseases by V.S. Pundhir (2000) 

• Disease resistance in plants by V.S. Pundhir (2001) 

• Seed Pathology: A Practical Manual by K. Vishunavat (2002) 

• Laboratory Methods in Plant Pathology by Pradeep Kumar, Y.P.S. Rathi, & H.S. Tripathi 

(2002) 

• Phytovirology: Laboratory Manual by Y.P.S. Rathi, H.S. Tripathi & Pradeep Kumar 

(2002) 

• Diagnosis of Plant Diseases by A.N. Tewari (2002) 

• Identification of Plant Disease by A.N. Tewari (2003) 

• Introductory Plant Pathology (UG) by Y.P.S. Rathi, P. Kumar, & H.S. Tripathi (2003) 

• Diagnosis of Plant Diseases: Laboratory Manual by A.N. Tewari (2004) 

• Mushroom Cultivation: Laboratory Manual by R.P. Singh (2004) 

• Crop Diseases and their Management by H.S. Chaube, V.S. Pundhir & S.N. 

Vishwakarma (2004) 

- 6 -


• Laboratory Manual of Forest Pathology by K. P.Singh, J. Kumar and P. Srinivas (2007) 

• Integrated Pest Management by Ruchira Tiwari, S.C.Saxena and Akhilesh Singh (2008) 

Technical Bulletins 

• Ascochyta blight of chickpea by H.S. Chaubey (1987) 

• Botrytis grey mold of chickpea: survival and management by Y.P.S. Rathi and H.S. 

Tripathi (1993) 

• Studies on sterility mosaic of pegion pea (Cajanus cajan (L) Millsp.) by Y.P.S. Rathi 

(1983) 

• Studies on Fusarium by R.S. Singh (1975) 

• Epidemiology and management of karnal bunt disease of wheat by Amerika Singh 

(1994) 

• Plant parasitic soil nematodes of India by K. Sitaramaiah, R.S. Singh, K.P. Singh and 

R.A. Sikora (1971) 

• False smut of rice by R.A. Singh (1984) 

• Disease controling potential of some fungicides in soil as affected by Physicochemical 

biological factors (IV volumes) by H.S. Chaube et al. (1993) 

• A Handbook on Scientific Writing by Y.P. S. Rathi (1998) 

• Major Diseases of Soybean and their Management by Pradeep Kumar and Y.P.S. Rathi 

(2005) 

• Disease Free Seed Production of Soybean by K. Vishunavat (2002) 

• Indian Minimum Seed Certification Standards by K. Vishunavat, K., R.S. Verma, P. K. 

Shrotria, S.N. Tiwari, and Omvati Verma (2003) 

• Studies on Epidemiology and Management of Rust of Field Pea by H.S. Tripathi (2003) 

Extension Bulletin 

• Crop Diseases: Farmers Question and our Answer- H.S. Chaube 

• Qlyksa ds jksx% fdlkuksa ds iz'u gekjs mRrj& ,p0 ,l0 pkScs 

• [kjhQ Qlyksa dh mUur [ksrh ,oe~ vU; d`f"k O;olk;&ds- ih- flag ¼2008½ 

• jch Qlyksa dh mUur [ksrh ,oe~ vU; d`f"k O;olk;&ds- ih- flag ¼2008½ 

• /kku dh [ksrh esa ,dhd`r uk'khtho izcU/k& ;w0 ,l0 flag 

• e`nk lkSjhdj.k& ,p0 ,l0 pkScs ,oa ,l0 ,u0 fo'odekZ 

• lsc ds eq[; jksx dhV ,oa mudk lesfdr izcU/ku& ds0 ih0 flag ,oa ts0 dqekj 

• lfCt;ksa esa lesfdr uk'khtho izcU/ku& ts0 dqekj 

RESEARCH 

Research work in the department began since the inception of the University. With the 

addition of new programme and staff strength, the research activities got diversified 

- 7 -


encompassing, Ecology of soil borne plant pathogens, Epidemiology and Forecasting, Biological 

control and IPM, Molecular Biology and Population Biology, Seed Pathology, Fungicides, 

Nematology, Phytovirology, Phytobacteriology and Biology & Technology of Mushroom 

Production. The department has several research projects funded by national and international 

funding agencies. The department is guiding the research work at the regional station such as 

Bharsar, Kashipur, Lohaghat, Majhera and Ranichauri on pathological aspects. The scientists of 

the department have won many national and international awards. 

The department is actively engaged in the research work on both fundamental and applied 

aspects in frontier areas of plant pathology. The plant protection technology developed by the 

department is being effectively communicated to the farming community of state of Uttarakhand. 

The department has to cater the needs of not only farmers of the plain but also of hills located at 

different altitudes. In hills crops, diseases and cropping practices vary a lot depending on altitudes 

and they are quite different from plain. This offers a big challenge to the Centre of Advanced 

Faculty Training in Plant Pathology. 

Significant Contribution 

• Cause and control of Khaira disease of rice 

• Development of selective media for isolation and enumeration of Pythium and Fusarium 

• Mechanism of biological control in soil amended with organic matters 

• Biology and characterization of legume viruses 

• Ecology of soil – borne pathogens (Fusarium, Pythium, Rhizoctonia solani, Sclerotium rofsii) 

• Mechanism of absorption, translocation and distribution of fungicides in plants 

• Methods for quantitative estimation of fungicides like metalaxyl, organotin compounds, carbendazim 

etc. 

• Hormonal action of fungicides 

• Phenolics in Plant disease resistance 

• Biological control with introduced antagonists 

• Etiology & management of mango malformation 

• Etiology and management of shisham wilt. 

• Epidemiology and Genetics of Karnal bunt fungus 

• Population biology of rice blast fungus, Magnaporthe grisea 

• Mechanism of intra-field variability in Rhizoctonia solani 

• Soil solarization 

• Mushrooms – Development of strains, and production technologies 

• Role of Ps. fluorescens in sporophores development of A. bisporus 

• Compost formulation with Sugarcane baggase + Wheat Straw, 2:1 developed to reduce cost of 

cultivation of Agaricus bisporus. 

• Developed chemical treatment (Formalin 15ml + Bavistin 0.5g/10kg compost) of long method 

compost to avoid the moulds in cultivation of A. bisporus. 

- 8 -


• Recommended supplementation of substrate with 2% mixture of Neem cake + Wheat straw + Rice 

bran + Soybean meal for Pleurotus spp. cultivation. 

• Standardized cultivation of Auricularia polytricha using sterilized wheat straw supplemented with 

wheat bran (5%). 

• Standardized cultivation of Lentinula edodes with substrate 

popular sawdust. 

• Systemic induced resistance in brassica. 

• Use of siderophore producing Pseudomonads for early fruiting 

and enhanced yield of Agaricus bisporus. 

Lentinula edodes 

• Use of Pseudomonas fluorescens for control of mushroom 

diseases caused by Verticillium, Sepedonium, Trichoderma and Fusarium. 

• Pleurotus sajor-caju and P. florida recommended for commercial cultivation using soybean straw / 

Paddy straw / Wheat straw / Mustard straw. 

• Standardized cultivation technology for Hypsizygus almarius 

using wheat straw supplemented with wheat bran. 

• Standardized cultivation of Calocybe indica using wheat 

straw as a substrate with casing of FYM + Spent Compost + 

Sand (2:1:1). 

• A relay cropping schedule developed for Tarai region of 

Uttarakhand: two crops Agaricus bisporus (Sept. - March), four crops Calocybe indica 

Pleurotus spp. (Sept.- Nov. and Feb.,- April) and three crops of Calocybe 

indica (March-October). 

• Developed two strains of Agaricus bisporus, Pant 31 and Pant 52, now included in multilocational 

testing under coordinated trials. 

• Development and commercialization of seven hybrids of oyster mushroom. 

• Associated with multilocational testing and release of the strains NCS-100, NCS-102, NCH-102 of 

A. bisporus. 

• 120 mushroom species from different locations in Uttarakhand 

have been collected and preserved in the museum of the 

centre. 

• Of the collected mushrooms five Auricularia, four species of 

Pleurotus and two species of Ganoderma have been brought 

under cultivation. 

• Developed / standardized technology for production of traditional 

value added mushroom products viz. ‘Sev’, ‘Warian’, ‘Papad’ 

and ‘Mathri’. 

Ganoderma lucidum 

• Isolated a high value cater pillar mushroom 

Cordyceps sinensis from high altitudes of 

Uttarakhand and analysed for antioxidative 

properties. 

Cordyceps sinensis 

- 9 -


MAJOR ACHIEVEMENTS 

‣ Twenty seven wheat lines, combining better agronomic characteristics and resistance to diseases 

including Karnal bunt have been identified (Shanghi-4, BW 1052, HUW 318, Lira/Hyan’S’ VUI’S’, 

CUMPAS 88, BOBWHITE, SPRW 15/BB/Sn 

64/KLRE/3/CHA/4/GB(K)/16/VEE/ GOV/AZ/MU, NI9947, Raj 3666, 

UP 1170, HS 265, HD 2590, HS317, PH 130, PH 131, PH 147, PH 

148, PH 168, HW 2004, GW 188, MACS 2496, CPAN 3004, K8804, 

K8806, ISWYN-29 (Veery”S”) and Annapurna). 

‣ Foliar blight of wheat has now been assumed as a problem in Tarai 

areas of U.P and foothills of Uttarakhand. Bipolaris sorokiniana - 

Dreschlera sorokiniana, was found associated with the disease in 

this area. Karnal bunt of wheat caused by Tilletia indica Mitra, is widely distributed in various 

Western and Eastern districts of U.P while the North hills and Southern dry areas are free from the 

disease. 

‣ Multiple disease control in wheat has been obtained by seed treatment with Raxil 2DS @ 

1.5g/Kg seed + one foliar spray fungicide Folicur 250 EW (Tebuconazole) @ 500ml/ha, which 

controls loose smut, brown rust, yellow rust, powdery mildew and leaf blight disease very 

effectively. 

‣ The mixture of HD 2329 + WH 542 + UP 2338 produced highest yield recording 11.67 per cent 

higher as compared to average yield of their components. 

‣ Among new fungicides Raxil 2DS (Tebuconazole) @ 1.0, 1.5, 2.0 and 2.5g/kg seed, Flutriafol 

and Dividend @ 2.5g/Kg seed were found highly effective in controlling the disease. Raxil 2DS 

@ 1.5g/Kg seed as slurry treatment gave complete control of loose smut. 

‣ New techniques for embryo count and seedling count for loose smut, modified partial vacuum 

inoculation method of loose smut, creation of artificial epiphytotics of Karnal bunt, NaOH seed 

soaked method for Karnal bunt detection and detached leaf technique for screening against 

leaf blight using pathogen toxin developed. 

‣ The major emphasis has been on the screening of maize germplasms to various diseases with 

special reference to brown stripe downy mildew, banded leaf and sheath blight and Erwinia 

stalk rot. A sick-plot has been developed to ensure natural source of inoculum. Efficient 

techniques for mass multiplication of inoculum and screening of germplasms have been 

developed to create epiphytotic conditions. The selected genotypes have been utilized for 

evolving agronomically adaptable varieties. Several promising hybrids and composites have 

developed and released following interdisciplinary approach. 

‣ Studies on estimation of yield losses, epidemiological parameters on various economically 

important diseases of maize have been worked out to evolve suitable control measures and 

have been recommended to farmers in the region. 

- 10 -


‣ Based on the survey and surveillance studies the information on the occurrence of various 

diseases in UP and Uttarakhand, a disease map has been prepared and monitored to finalize the 

out breaks of one or more diseases in a given area based on weather parameters. It will help the 

growers to be prepared to save the crop from recommended plant protection measures. 

‣ A repository of >600 isolates of biocontrol agents developed at Pantnagar & Ranichauri. These 

isolates are suited for different crops & agro-ecological conditions. 

‣ Standard methods developed for testing hyphal and sclerotial colonization. 

‣ Isolate of T. virens capable of colonizing sclerotia of Rhizoctonia, Sclerotium and Sclerotinia 

isolated for the first time. It may have great potential. 

‣ 16 new technologies related with mass multiplication and formulation of microbial bio-agents 

developed and are in the process of being patented. 

‣ Several genotypes including SPV 462, SPV 475, SPV 1685, SPH 1375, SPH 1420, CSV 13, 

CSV 15, CSH 14, CSH 16, CSH 18, G-01-03, G-09-03, GMRP 91, RS 629, UTFS 45, UTMC 

523 and AKR 150 have been identified with high level of resistance to anthracnose and zonate 

leaf spot diseases. 

‣ Biocontrol agents T. harzianum and P. fluorescens have been found effective in increasing the 

growth of plants and reducing the severity of zonate leaf spot. G. virens and T. viride have 

been found most effective against anthracnose pathogen of sorghum. 

‣ The cause of Khaira as zinc deficiency was established for the first time and zinc sulphate 

+slacked lime application schedule was developed for the control of the disease 

‣ Inoculation technique was developed to create “Kresek” phase in rice seedlings. Pre-planting root 

exposure technique in a suspension of 10 8 cells/ml for 24 hrs gave the maximum “Kresek”. Root 

inoculation, in general was found better for development of wilt symptoms than shoot inoculation. 

‣ A simple technique has been developed to detect the pathogen in and/or on seeds. The 

presence of viable pathogen has been demonstrated from infected seeds stored at room 

temperature up to 11 months after harvest. 

‣ The disease is sporadic in occurrence often becomes serious in nature. Chemical control trials 

showed that the disease can effectively be controlled by giving 2-3 foliar sprays of 

streptocycline @ 15 g/ha. 

‣ A number of new fungicides along with recommended ones and botanicals were tested against 

sheath blight. Foliar sprays with Anvil, Contaf, Opus, Swing and RIL F004 @ 2 ml/l and Tilt @ 

1 ml/l were found highly effective in controlling sheath blight. Foliar sprays with Neem gold @ 

20 ml /lit. or Neem azal @ 3ml/lit. was found significantly effective in reducing sheath blight 

and increasing grain yield. 

‣ Foliar sprays with talc based formulations of the bioagents (Trichoderma harzianum, or 

Pseudomonas fluorescence, rice leaf isolates) were found effective in reducing sheath blight 

and increasing grain yield. Foliar sprays with the bioagents (T.harzianum) or P. fluorescens) 

- 11 -


given 7 days before inoculation with R. solani was highly effective against the disease. 

‣ Seed or soil treatment with T. harzianum or P. fluorescens @ 2, 4 or 8 g/kg enhanced root and 

shoot growth and fresh and dry weight of rice seedlings. 

‣ Seed treatment with fungorene followed by one spray of carbendazim (@ 0.05% at tillering at 

diseases appearance) and two sprays of Hinosan @ 0.1% at panicle initiation and 50% 

flowering was most effective and economical treatment in reducing the disease intensity and 

increasing the yield. 

‣ For the first time, true sclerotia were observed in Kumaon and Garhwal regions at an altitude of 

900 m above. True sclerotia have a dormancy period of approximately six months. Exposure of 

sclerotia to near ultraviolet radiation for an hour breaks the dormancy and increased 

germination. 

‣ Effect of different physical factors and extracts on the germination of true sclerotia was studied. 

Maximum germination was observed at 25 0 C and at pH 6.0, in fluorescent light. Among the 

substratum, maximum germination occurred on moist sand. Soil extract was more favourable 

than other extracts. The number of stipes and mature head formation was directly correlated 

with the size and weight of the sclerotia. 

‣ The viability of the 3 propagules namely; conidia, pseudo and true sclerotia stored under 

different conditions showed that conidia remain viable from 2-3 months, pseudo- sclerotia from 

4-6 months and true sclerotia up to 11 months at room temperature and under field conditions. 

True sclerotia buried at different depth (2.5 to 10 cm) in soil germinated well, but scleroita 

buried at 15 cm depth did not germinate and rotted. 

‣ Discoloured grains of various types were grouped according to their symptoms. The fungi 

responsible for each type of symptoms were identified. Ash grey discolouration of glumes 

separated by dark brown band was caused by Alternaria alternata and Nigrospora oryzae. 

Spots with dark brown margin and ash grey centre by Curvularia lunata and Alternaria 

alternata, light yellow to light brown spots by C. pallescens, Fusarium equiseti and N. oryzae, 

Brown to black dot by Phyllosticta oryzae Dark brown to black spot and specks by Drechslera 

victoriae, D. rostratum and D. oryzae, light to dark brown glumes by Sarocladium oryzae and 

D. oryzae, and light to dark brown spots by D. Australiense. 

‣ Rice varieties Manhar, Narendra 80, Saket 7, Ajaya, Bansmati, 385 showed higher incidence 

(34.1 to 41.8%) whereas Sarju 52, UPR 1561-6-3, Pusa 44, Jaya, Pant Dhan 10 and improved 

Sharbati exhibited lower (18.4-22.3%) incidence of seed discolouration. Bipolaris oyzae 

caused highest seed discolouration which is followed by Fusarium moniliforme, curvularia 

lunata and Fusarium graminium in all the test varieties. 

‣ On the basis of the symptoms pattern and transmissibility of the pathogen through grafting and 

eriophyied mite (Aceria cajani), presence of foreign ribonucleic protein and nuclear inclusion 

like bodies in the phloem cell indicated the viral (RNA virus) nature of the pathogen of sterility 

- 12 -


mosaic of pigeon pea. The vector mite of the pathogen was found on lower surface of leaves 

of Canavis sativus and Oxalis circulata weeds in this area. Mild mosaic, ring spot and severe 

mosaic symptoms were observed in different as well as same cultivar. This observation reveals 

the presence of variation in the pathogen. 

‣ Germplasm lines/ cultivars screened viz; ICP 14290, ICP 92059,ICP 8093, KPBR 80-2-2, PL 

366, ICPL 371, Bahar, NP (WR) 15.were found resistan against Phytophthora stem blight of 

pea. 

‣ Some resistant donors for mungbean yellow mosaic virus have been identified i.e. UPU- 

1,UPU-2,UPU-3, UG-370, PDU-104, NDU-88-8, UG-737, and UG-774. The varieties thus 

evolved include PU-19, PU- 30, and PU-35., Many, resistant lines/cultivars identified: ML-62, 

ML-65, Pant M-4, Pant M-5, ML-131, NDM 88-14, ML-682, PDM-27, ML- 15, ML-803, ML-682 

and 11/ 395 and for Urdbean leaf crinkle virus, SHU 9504, -9513,-9515, -9516, -9520, -9522, - 

9528, KU 96-1, UG 737 and TPU-4. 

‣ Seed treatment with carbendazim (0.1%) followed by two prophylactic sprays of carbendazim 

(0, 05%) or Dithane M-45 @ 0.25% was found most effective in reducing disease severity of 

anthracnose disease. In early sown crop high disease severity was observed while in late 

sown crop low disease severity was recorded. Inter cropping with cereals or pulses have no 

effect on anthracnose severity. 

‣ Propiconazol 0.1%, carbendazim 0.1%, hexaconazol 0.1%, mancozeb 0.25% sprayed plots 

have low disease severity and high grain yield against Cercospora leaf spot. 

‣ Studies on integrated management of wilt/root rot/collar rot showed that Seed treatment with 

fungicide alone or in combination with other fungicides/ bio agents were found effective. 

Among the fungicides seed treatment with Bavistin + Thiram (1:2), vitavax + Thiram (1:2), 

vitavax, Bavistin, Bayleton, Bio agent Gliocladium virens + Vitavax 

and Pseudomonas fluorescence) decreased the seedling mortality, 

improved germ inability, plant stand and yield. 

‣ Eleven thousand germplasm lines/ breeding populations F 2 , F 3, F 4 

and F 5 generations were screened. Many germplasm/ accessions 

were found resistant/ tolerant to Botrytis gray mould viz; ICC 1069, 

ICC 10302, ICCL 87322, ICC 1599, -15980, - 8529, ICCV 88510, E100Y (M) BG 256, BG261, 

H86-73, IGCP 6 and GNG 146. 

‣ Lentil entries evaluated under sick plot for wilt/root rot/ collar rot diseases. The following lines 

were found promising viz; LL 383, PL 81-17, LH 54-8, DPL-58, DPL 14, Jawahar Massor- 3, 

DPL 112, IPL-114, L 4147 and Pant L 639. 

‣ The promising germplasm lines/ cultivars are as follows: DPL 62, PL-406, L 4076, TL 717, E 

153, IPL 101, IPL 105, PL- 639, LH 84-8, and Precoz . 

‣ The field pea lines were found promising JP 141, Pant P-5, KFPD 24 (swati), HUDP 15, KFPD- 

- 13 -


2, HFP-4, P1361, EC-1, P-632, P 108-1, KPMR 444, KF 9412, DPR 48, T-10, KPMRD348, 

DDR13, IM9102, KFP 141 and KPMR 467 against powdery mildew and JP 141, Pant P-5, P 

10, FP 141, KDMRD 384, HUDP-9, HUP-2 and T-10 were found promising against rust 

disease. 

‣ Mid-September planting or early October planting of rapeseed-mustard has been found to 

escape from Alternaria blight (Alternaria brassicae) downy mildew (Peronospora parasitica) 

and white rust (Albugo candida) diseases as against mid and late October planting. In general 

high occurrence of the floral infection (staghead phase) of white rust and downy mildew during 

flowering period has been found to be associated with reduced period, i.e. 2-6 hours, of bright 

sunshine/day concomitant with the mean maximum temperature of 21-25 0 C, the mean 

minimum temperature of 6-10 0 C and higher total rainfall up to 166 mm. Bright sunshine hours 

/day has a significant negative correlation whereas total rainfall has a significant positive 

correlation with staghead development. 

‣ All the three important foliar diseases of rapeseed-mustard could be effectively controlled by 

following integrated package of balanced N 100 P 40 K 40 application, early October sowing and 

treating the seed with Apron 35 SD @ 6g kg -1 seed followed by spray of mixture of metalaxyl + 

mancozeb (i.e Ridomil MZ 72 WP @ 0.25%) at flowering stage and by spray of mancozeb or 

iprodione @ 0.2% at pod formation stage. In situations where Sclerotinia stem rot and / or 

powdery mildew appeared to be important in a particular crop season, a spray of mixture of 

carbendazim (0.05%) + mancozeb (0.2%) was found to give excellent cost effective control of 

the diseases with significant increase in seed yield of the crop. 

‣ Among the botanicals, leaf extracts of Eucalyptus globosus (5%) and Azadirchta indica (5%) 

have been proved to exhibit greater antifungal activity against A. brassicae and Albugo 

candida and showed significant reduction in the severity of Alternaria blight and white rust 

diseases which was rated to be at par with mancozeb fungicide spray. 

‣ Some abiotic chemical nutrient salts such as calcium sulphate (1%), zinc sulphate(0.1%) and 

borax (0.5%) and biocontrol agents such as Trichoderma harzianum and non-aggressive D 

pathotype of A.brassicae have been shown to induce systemic host resistance in mustard 

against aggressive “A” pathotype of A. brassicae and virulent race(s) of A. candida. 

‣ The staghead phase in B. juncea has been investigated to be due to A. candida and not due P. 

parasitica. Tissues at the staghead phase become more susceptible to P. parasitica than 

normal tissues of the same plant. 

‣ B. juncea genotypes (EC 399296, EC 399299, EC 399301, EC 399313, PAB-9535, Divya 

Selection-2 and PAB 9511), B. napus genotypes (EC 338997, BNS-4) and B. carinata (PBC- 

9221) have been shown to possess resistance to white rust coupled with high degree of 

tolerance to Alternaria blight. Reduced sporulation is identified to be the major component for 

slow blighting. 

- 14 -


‣ B. juncea (RESJ 836), B. rapa (RESR 219) and B. napus (EC 339000) have been selected for 

resistance to downy mildew and for high yield performance. Total 52 genotypes of mustard 

representing at least 12 differential resistance sources, 23 lines of yellow sarson representing 

6 differential resistance sources and 54 lines of B. napus representing 3 differential resistance 

sources to downy mildew have been identified. 

‣ A new short duration (95-100 days) short statured (85- 96 cm) plant type of mustard strain 

‘DIVYA’ possessing high degree of tolerance to Alternaria blight suitable for intercropping with 

autumn sown sugarcane and potato yielding with an average of 15-22 q ha -1 has been 

developed. This ‘Mustard DIVYA’ plant type is now recommended as a source for breeding 

more and more improved varieties of mustard as it has been proved to have good general 

combining ability for short stature characteristics. 

‣ Seed treatment with mancozeb @ 0.2% + thiram @ 0.2% has been found to control seed, 

seedling and root rot diseases of groundnut. However seed treatment with thiram @ 0.2% + 

vitavax @ 0.2% has been found to control collar rot (Sclerotium rolfsii) of groundnut. Two 

sprays of carbendazim @ 0.05% have been found to give excellent control of early and late 

leaf spot (tikka disease) of groundnut. 

‣ Mid September planting of sunflower was found to escape the occurrence of major diseases 

like Sclerotinia wilt and rot, Sclerotium wilt, charcoal rot and toxemia. Severity of Alternaria 

blight was found to be negligible and did not cause any reduction in yield. The crop could be 

harvested by 15 th December. The yield obtained was 16 q/ha. 

‣ The average percent loss has been noted in the range of 50.6 to 80.7 percent due to Alternaria 

blight disease under Kharif conditions. However, the percent loss in oil has been shown in the 

range of 21.6 to 32.3. To control the disease, total 4 sprays of mancozeb @ 0.3% at 10 day 

interval have been found effective. 

‣ A repository of about 5000 rice blast isolates was made from 30 locations in Indian Himalayas at 

Hill Campus, Ranichauri. Blast pathogen population from the region was analyzed using molecular 

markers and phenotypic assays. Most locations sampled and analyzed had distinct populations 

with some containing one or a few lineages and others were very diverse. Within an 

agroecological region migration appeared to be high. The structure of some populations could be 

affected to some extent by sexual recombination. 

‣ Magnaporthe grisea isolates derived from Eleusine coracana, Setaria italica and Echinochloa 

frumentaceum collected from a disease screening nursery were cross compatible. The 

chromosome number of each isolate was found to be six or seven. Similarity of karyotypes was 

found among isolates with in a lineage though between lineages some variability was noticed. A 

remarkable similarity between karyotypes of Eleusine coracana and Setaria italica was observed. All 

of these isolates were fertile and mated with each other to produce productive perithecia. The 

existing data however showed no evidence of genetic exchange among host-limited M. grisea 

- 15 -


populations in Indian Himalayas. 

‣ No strong relationship appeared between the number of virulences in a pathotyope and its frequency 

of detection. The frequency of virulent phenotype to a cultivar and susceptibility of that cultivar in the 

field did not correspond. The number of virulences per isolate was in general less than the number 

of virulences per pathotype, which indicated predominance of isolates from pathotypes with fewer 

virulences. There was a tendency for the pathotypes to have fewer virulences. The frequency of 

virulence among rare pathotypes was higher than common pathotypes against all the differential 

NILs, including two-gene pyramids. These rare pathotypes could be the potential source of 

resistance breakdown of the novel resistance genes. 

‣ Blast resistant gene Pi-2(t) appeared to have the broadest and Pi-1(t) the narrowest resistant 

spectra. Compatibility to Pi-2 (t) gene did not appear to limit compatibilities with other resistant 

genes. Loss of avirulence to all the five major gene tested may carry a serious fitness penalty. 

Major gene Pi-2 and gene combination Pi-1,2 showed least compatibilities and hold promise 

in managing blast in the region. In the overall Himalayan population, gene combinations in 

general were effective at most locations. Combination of Pi-1+2 genes was effective at most 

locations until the year tested. However, three gene pyramid [Pi-1(t) + Pi-2(t)+Pi-4(t)] resisted 

infection at all locations. 

‣ It was inferred that the pathotype composition of the blast pathogen composition in the Indian 

Himalayas was very complex and diversifying the resistance genes in various rice breeding 

programmes should prove to be a useful strategy for disease management. 

‣ A common minimum programme under bio-intensive IPM in vegetables in Uttaranchal hills was 

designed that is extended to over 2000 farmers from 20 villages in district Tehri Garhwal. 

‣ Epidemiological considerations in the apple scab disease management led to the development 

of disease prediction models. Relation of degree-day accumulations to maturation of 

ascospores, and potential ascospore dose (PAD) were found to be useful for predicting the 

total amount of inoculum in an orchard thereby effectively improving apple scab management. 

‣ Out of 71 genotypes tested against red rot of sorghum caused by Colletotrichum falcatum, four 

genotypes viz; Co Pant 92226, Co Pant 96216, Co Pant 97222 and CoJ 83 were found 

resistant and another 24 exhibited fairly good tolerance. 

‣ Seed treatment with Thiram + Carbendazim (2:1) @ 3g/kg seed or Vitavax 0.2% controlled the 

seed and seedling rots and improved the seedling emergence without any adverse effect on 

the nodulation and invariably yield were increased. Seed treatment with Trichoderma 

harizianum, T. viride or Pseudomonas fluorescens @ 10g/kg controlled seed and seedling rots 

and increased plant emergence. 

‣ Purple seed stain disease can be effectively controlled by seed treatment with thiram + 

carbendazim (2:1) @ 3 g/kg seed followed by two sprays of benomyl or Carbendazim @ 0.5 

kg/ha. 

- 16 -


‣ Rhizoctonia aerial blight of soybean can be effectively controlled by two sprays of carbendazim 

@ 0.5 kg/ha. Seed treatment with T. harzianum or Pseudomonas fluorescens 10g/kg seed + 

soil treatment with pant Bioagent-3 mixed with FYM @50q/ha followed by two sprays of T. 

harzianum @ 0.25% reduced the disease severity of RAB. 

‣ Pod blight and foliar diseases caused by Colletrotichum dematium var truncatum could be 

effectively controlled by the use of carbednazim 0.05%, Mancozeb 0.25%, Copperoxychloride 

0.3%, Thiophanate methyl 0.05%, Chlorothalonil 0.25%, Hexaconazole 0.1% and 

Propiconazole 0.1%. First spray should be given as soon as disease appear and second spray 

after 15 days of first spray. 

‣ Rust disease of soybean could be effectively controlled with three sprays of Benomyl 0.05%, 

Mancozeb 0.25% or Zineb 0.25%, at 50, 60 and 70 days after sowing. Varieties Ankur, PK- 

7139, PK-7394, PK-7121, PK-7391 were resistant. 

‣ Charcoal rot disease can be effectively controlled by seed treatment with Trichoderma 

harzianum @ 0.2% + vitavax @ 0.1%. 

‣ Pre-mature drying problem Soybean can be minimized by seed treatment with carbendazim + 

Thiram (2:1) @ 3g/kg seed followed by two sprays with carbendazim, mancozeb and 

Aureofungin. Varieties PSS-1, PS-1042, PK-1162, PK-1242 and PK-1250 were found to be 

superior for premature drying problem. 

‣ Integrated disease management (IDM) modules based on combined use of cultural practices, 

fungicides for fungal disease, insecticide for virus disease and host resistance were evaluated 

against RAB and Soybean yellow Mosaic virus diseases. 

‣ Bacterial pustules can be successfully controlled by two sprays at 45 and 55 days after 

planting with a mixture of Blitox-50 (1.5 kg/ha) + Agrimycin-100 (150g/ha) or streptocycline 

(150 g/ha) + copper sulphate (1kg/ha). 

‣ Soybean yellow Mosaic can be very effectively controlled by four sprays with oxymethyl 

demoton @ 1l/1000 lit/ha at 20, 30, 40 and 50 days after planting. Soil application with Phorate 

10G @ 10 kg/ha and Furadan 3G @ 17.5 kg/ha controlled the disease. Varieties PK-1284, 

1251, 1259, 1043, 1225, 1303, 1314, 1343, 1347, PS-1042 PS-564, 1364 were identified as 

resistant to Soybean yellow Mosaic virus. 

EXTENSION 

The scientists also participate in the farmers contact programme as well as practical 

trainings at different levels including those of IAS and PCS officers, Extension workers, Agricultural 

officers, Farmers, Defense Personnels etc. The Scientists of the department also actively 

participate in the trainings organized under the T&V programme for the benefit of farmers/State 

level Agricultural Officers. Two Professors (Extension Pathology) and crop disease specialists are 

deputed to “Help Line Service” started recently by the University under Agriculture Technology 

- 17 -


Information Centre (ATIC). The telephone number of help line services is 05944-234810 and 1551. 

Technology developed by the centre is regularly communicated to the farmers of the 13 districts of 

Uttarakhand State through the extension staff (Plant Protection) of both university and state 

agriculture and horticulture departments posted in all districts of the state. The radio talks and TV 

programme are delivered. Popular articles and disease circulars are published regularly for the 

benefit of the farmers. 

UPGRADATION TO CENTRE OF ADVANCED STUDIES 

In view of the outstanding quality of teaching, research and extension work being carried out in 

the Department, ICAR in 1995 upgraded the department to the status of the Centre of Advanced 

Studies in Plant Pathology (CAS) and now has been upgraded to Centre of Advanced Faculty 

Training (CAFT). Major mandate of the CAFT is to train scientific faculty from all over the country in 

important and innovative areas of Plant Pathology. So far 27 trainings, with 559 participants from 25 

states, have been held The CAS was awarded by the education division, ICAR on August 14, 1998 a 

certificate of appreciation in commemoration of Golden Jubilee year of independence (1998) for 

organizing the programmes for human resource development and developing excellent instructional 

material. The progress report of CAS/CAFT in Plant Pathology is as follows: 

- 18 -

Trainings Held 


1. Recent advances in biology, epidemiology and management of diseases of major kharif 

crops (Sept. 19- Oct. 12, 1996) 

2. Recent advances in biology, epidemiology and management of diseases of major rabi crops 

(Feb. 25 –March 17, 1997) 

3. Ecology and ecofriendly management of soil-borne plant pathogens (Jan 12 – Feb. 02, 1998) 

4. Advanced techniques in plant pathology (Oct. 12 – Nov. 02, 1998) 

5. Recent advances in detection and management of seed-borne pathogens (March 10-30, 

1999) 

6. Recent advances etiology and management of root-rot and wilt complexes (Nov. 26 – Dec. 

16, 1998) 

7. Integrated pest management with particular reference to plant diseases: concept, potential 

and application (Nov. 23 –Dec. 13, 2000) 

8. Recent advances in research on major diseases of horticultural crops (March 01-30, 2001) 

9. Recent advances in plant protection technology for sustainable agriculture (Nov. 19 –Dec. 

09, 2001) 

10. Plant diseases diagnosis: past, present and future (Feb. 13, - March 05, 2002) 

11. Chemicals in plant protection: past, present and future (Jan. 28 – Feb. 17, 2003) 

12. Eco-friendly management of plant diseases of national importance: present status and 

research and extension needs (Nov. 10-30, 2003) 

13. Ecologically sustainable management of plant diseases: status and strategies (March 22- 

April 11, 2004) 

14. Disease resistance in field and horticulture crops: key to sustainable agriculture (Dec. 10-30, 

2004) 

15. Regulatory and cultural practices in plant disease management (Dec. 03-21, 2005) 

16. Crop disease management: needs and outlook for transgenics, microbial antagonists and 

botanicals (March 21 – April 10, 2006) 

17. Soil Health and Crop Disease Management (December 02-22, 2007) 

18. Role of Mineral Nutrients and Innovative Eco-friendly Measures in Crop Disease 

Management (March 22- April 11, 2007) 

19. Plant Disease Management on Small Farms (January 03-23, 2008) 

20. Seed Health Management for Better Productivity (March 28 to April 17, 2008) 

21. Recent Advances in Plant Disease Management (Dec. 13, 08 to Jan. 02, 09) 

22. Recent Advances in Biological Control of Plant Diseases (March 20 - April 09, 2009) 

23. Plant Pathology in Practice (March 22 to April 11, 2010) 

24. Climate change, precision agriculture and innovative disease control strategies (March 23 to 

April 12, 2011) 

25. Quality Management and Plant Protection Practices for enhanced competitiveness in 

- 19 -


agricultural export (November 12 to December 02, 2011) 

26. Diseases and Management of Crops under Protected Cultivation (September 04-24, 2012). 

27. Managing Plant Microbe Interactions for the Management of Soil-borne Plant Pathogens 

(January 22 to February 11, 2013) 

Participations 

Sl. No. State Total Sl. No. State Total 

1. Andhra Pradesh 15 14. Maharashtra 40 

2. Arunachal Pradesh 02 15. Manipur 01 

3. Assam 13 16. Meghalaya 01 

4. Bihar 25 17. Nagaland 01 

5. Chattishgarh 08 18. Orissa 13 

6. Gujarat 45 19. Punjab 06 

7. Haryana 04 20. Rajasthan 45 

8. Himanchal Pradesh 39 21. Sikkim 01 

9. Jammu & Kashmir 34 22. Tamil Nadu 17 

10. Jharkhand 05 23. Uttar Pradesh 73 

11. Karnataka 28 24. Uttarakhand 91 

12. Kerla 05 25. West Bengal 18 

13. Madhya Pradesh 29 26. -- -- 

Total = 559 

INFRASTRUCTURE 

• Wheat Pathology Lab. – General Path, Epidemiology, Toxin, Tissue Culture 

• Maize Pathology Lab. – General Plant Pathology, Bacteriology 

• Rice Pathology Lab. – General Plant Pathology 

• Ecology and Vegetable Pathology Lab. – Ecology, Histopathology, Biocontrol, Nematodes 

• Soybean Path. Lab.– General Plant Pathology, Fungicides 

• Oil Seed Path. Lab.– General Pl. Path., Tissue, Culture, Histopathology, Toxins 

• Pulse Path. Lab. – General Pl. Path., Phytovirology 

• Seed Path. Lab. – General Path, Seed Borne diseases 

• Biocontrol Lab. – Biocontrol & IPM 

• Molecular Pl. Path Lab. – Population biology & host- pathogen interaction 

• Mushroom Research & Training Centre – Research & training 

• Glass houses – 3 

- 20 -


• Polyhouses – 3 

• UG Practical Lab – 1 

• PG Lab – 1 

• Training Hall – 1 

• Conference Hall – 1 

• Office – 1 

Huts for Mushroom Production 

- 21 -


Research Project (on going) 

‣ Programme Mode Support in Agrobiotechnology Phase-II (DBT) 

‣ Translational Research Centre on Biopesticides (DBT) 

‣ All India Coordinated Research Project on Biological Control (ICAR) 

‣ All India Coordinated Wheat and Barley Improvement Project (ICAR) 

‣ All India Coordinated Rice Improvement Project (ICAR) 

‣ Cereal Systems Initiative for South ASIA (CSISA) Objective 3 (IRRI) 

‣ Chitosan/Copper-Nanoparticles and Biopesticides for Knowledge-Based Plant Protection 

(DBT) 

‣ Large Scale Demonstration of IPM Technology through KVKs in Network Mode (HTMM-I) 

‣ All India Coordinated Chickpea Improvement Project (ICAR) 

‣ All India Coordinated Pigeonpea Improvement Project (ICAR) 

‣ All India Coordinated MullaRP Improvement Project (ICAR) 

‣ All India Coordinated Soybean Improvement Project (ICAR) 

‣ All India Coordinator Research Project on Rapeseed & Mustard (ICAR) 

‣ All India Coordinated Research Project on Seed Technology Research (NSP) (ICAR) 

‣ DUS Test Centre for Implementation of PVP-LEGISLATION for Forage Sorghum at 

Pantnagar (ICAR) 

‣ All India Coordinated Potato Improvement Project (ICAR) 

‣ Pest risk assessment of potato crop in Kumaon Region of Uttarakhand (HTMM-I) 

- 22 -


‣ All India Coordinated Maize Improvement Project (ICAR) 

‣ Demonstration of Bio-intensive Integrated Pest Module in Tomato (NHB) 

‣ All India Coordinated Sugarcane Improvement Project (ICAR) 

‣ All India Coordinated Sorghum Improvement Project (ICAR) 

‣ All India Coordinated Mushroom Improvement Project (ICAR) 

‣ Demonstration of Existing Mushroom Production Technologies (HTMM-I) 

Total Budget Outlay – > 1000 lakhs 

Research Areas – Biological Control, IPM, Shisham wilt, Soil solarization, Population Biology, 

Seed pathology, Mushroom etc. 

Publication 

1. Books - 60 

2. Research Bulletins - 20 

3. Research Papers - >1200 

4. Conceptual / Review articles - >130 

5. Chapters contributed to book - >150 

6. Extension literature - over (200) 

(Hindi – English) 

Annual Review of Phytopathology - 02 

Recognition and Awards: 

• UNO (Rome) – Dr. Y. L. Nene 

• Prof. M. J. Narisimhan Academic Award (IPS) 5 

• Jawahar Lal Nehru Award (ICAR) 2 

• Pesticide India Award (ISMPP) 7 

• P. R. Verma Award for best Ph. D. Thesis (ISMPP) 2 

• Other (Hexamar, MS Pavgi, Rajendra Prasad etc.) >21 

• Uttaranchal Ratana 2 

• Education Award 2004-05” for his book “Qyksa ds jksx” 01 

by the Ministry of Human Resource Development, GOI 

Professional Societies and our Share: 

Indian Phytopathological Societies 

Presidents – 3 

Zonal Presidents – 3 

Indian Society of Mycology & Plant Pathology – 

Presidents – 3 

Vice Presidents – 1 

Indian Soc. Seed Technology 

Vice Presidents - 3 

- 23 -


Science Congress 

President (Agriculture Chapter) - 1 

National Academy of Agricultural Sciences 

Fellows - 3 

Future Strategies 

Teaching: Introduction of new courses 

Methods in Biological Control 

Plant disease of national importance 

Integrated plant disease management 

Molecular plant pathology 

Advances in mushroom production 

Research thrust: 

• Biological control & ICM (IPM + INM) in different crops/cropping systems 

• Disease management under organic farming 

• Microbial ecology 

• Green chemicals 

• Population biology of pathogens (including use of molecular tools) 

• Induced resistance 

• Exploitation of indigenous edible and medicinal mushrooms 

Human Resource Development 

Degree awarded 

M.Sc. 335 

PhD 198 

Trainings organized No. Persons trained 

Summer schools (ICAR) 5 136 

Summer training (DBT) 1 24 

International training (IRRI) 1 11 (8 countries) 

Under CAS/CAFT 27 559 

Mushroom Production Training 13 315 

Under SGSY on Mushroom Production 60 1785 

Under HTM on Mushroom 21 574 

Under RKVY on IPM 76 4130 

Under HTM on IPM 90 2292 

Under Seed Technology Research 05 150 

Future Goal 

Ecologically sustainable management of plant diseases to ensure both food security & 

safety through education, research & extension 

- 24 -


Management of Pests in Protected Cultivation-Problems & Perspectives 

H.S. Tripathi and Santosh Kumar 

Department of Plant Pathology, G.B.P.U.A .& T., Pantnagar-263 145 (UK) 

Protected Cultivation and the Role of Crop Protection 

The purpose of growing crops under greenhouse conditions is to extend their cropping 

season and to protect them from adverse environmental conditions, such as extreme temperatures 

and precipitation, and from diseases and pests (Hanan et al., 1978). Greenhouse structures are 

essentially light scaffolding covered by sheet glass, fibreglass or plastic. Such materials have a 

range of energy-capturing characteristics, all designed to maximize light transmission and heat 

retention.Modern technology has given the grower some powerful management tools for 

production. Generally, added-value crops are grown under protection. Most of them are labourintensive 

and energy-demanding during cold weather. Greenhouse production therefore, normally 

requires a high level of technology to obtain adequate economic returns on investments. Quality is 

a high priority for greenhouse crops, requiring much care in pest and disease management, not 

only to secure yields but also to obtain a high cosmetic standard. Although technological changes 

are ultimately intended to reduce production costs and maximize profits, precise environmental 

and nutritional control push plants to new limits of growth and productivity. This can generate 

chronic stress conditions, which are difficult to measure, but apparently conducive to some pests 

and diseases. Historically, not enough attention has been paid to exploiting and amending 

production technology for the control of pests and diseases. This makes the control of pests and 

diseases in protected crops even more challenging, with many important problems being 

unresolved and new ones arising as the industry undergoes more changes in production systems. 

Importance of Protected Crops for Plant Production 

Greenhouses were initially built in areas with long, cold seasons to produce out-of season 

vegetables, flowers and ornamental plants. Northern Europe is the paradigm of pioneering areas 

of greenhouse cultivation. Greenhouses protect crops against cold, rain, hail and wind, providing 

plants with improved environmental conditions compared to the open field. In greenhouses, crops 

can be produced out-of-season year-round with yields and qualities higher than those produced in 

the open field. Greenhouses have also allowed the introduction of new crops, normally foreign to 

- 25 -

the region (Germing, 1985). 


There are two basic types of greenhouse. The first type seeks maximum control in an 

environment to optimize productivity. In Europe, optimal conditions for year-round production are 

provided in the glasshouses of The Netherlands, Belgium, the UK and Scandinavia. The other type 

of greenhouse, which is very common throughout the Mediterranean area, provides minimal 

climatic control, enabling the plants grown inside to adapt to suboptimal conditions, survive and 

produce an economic yield (Enoch, 1986; Tognoni and Serra, 1989; Castilla, 1994). 

Reuveni et al,, (2008) observed a reduction in the number of infection sites of B. cinerea 

on tomato and cucumber when a UV-absorbing material was added to polyethylene film to 

increase the ratio of blue light to transmitted UV light. Blue photo selective polyethylene sheets 

have been suggested for their ability to reduce grey mould on tomato (Reuveni and Raviv, 1992) 

and downy mildew on cucumber (Reuveni and Raviv, 1997). Green-pigmented polyethylene 

reduced the conidial load and grey mould in commercial tomato and cucumber greenhouses by 

35–75%. Sclerotinia sclerotiorum on cucumber, Fulvia fulva (Cooke) Cif. (= Cladosporium fulvum 

Cooke) on tomato and cucumber powdery mildew were also reduced (Elad, 1997). 

The influence of greenhouse structures and covers on greenhouse climatic regimes may 

have strong consequences for pests and their natural enemies, as they have for diseases. In hightech 

greenhouses, regulation of temperature and water pressure deficit enables the creation of 

conditions less favorable to pathogens and, in some cases, more favorable to bio control agents. 

The use of heating to limit development of a number of pathogens is well known (Jarvis, 1992). 

The use of high root temperatures in winter grown tomatoes in rock wool offers a non-chemical 

method of controlling root rot caused by Phytophthora cryptogea Pethybr. & Lafferty. The high 

temperature was shown to enhance root growth while simultaneously suppressing inoculum 

potential and infection, and, consequently, reducing or preventing aerial symptoms (Kennedy and 

Pegg, 1990). Careful control of the temperature also proved important in the case of 

hydroponically grown spinach and lettuce, in which it prevented or reduced attack by both Pythium 

dissotocum Drechs. and Pythium aphanidermatum (Edson) Fitzp. (Bates and Stanghellini, 1984). 

Recently, attacks of P. aphanidermatum on nutrient film technique (NFT) grown lettuce in Italy 

were related to the high temperature (>29°C) of the nutrient solution. Root rot was inhibited by 

reducing the temperature below 24°C (Carrai, 1993).Productivity is manifold in greenhouses in 

comparison to growing the vegetables in open field as shown in the table below: 

Table: Performance of tomato varieties under polyhouse and open field conditions in NEH region 

(Barapani) 

Varieties Polyhouse Open field Varieties Polyhouse Open field 

yield (q/ha) yield (q/ha) 

yield (q/ha) yield (q/ha) 

BT-117-5-3-1 342.00 115.00 selection-2 233.00 73.83 

KT-10 283.60 117.40 selection-1 2000.98 84.03 

BT-10 294.00 111.65 KT-15 211.60 51.65 

Arka Alok 260.00 57.90 H-24 143.17 58.75 

BT-12 302.40 101.00 Arka Abha 193.50 70.33 

- 26 -

Status 


Commercial greenhouses with climate-controlled devices are very few in the country. Solar 

Green houses comprising of glass and polyethylene houses are becoming increasingly popular 

both in temperate and tropical regions. In comparison to other countries, India has very little area 

under greenhouses as is evident from Table below: 

Table: Approximate area (ha) under greenhouses 

Country Area Country Area 

Japan 54000 Turkey 10000 

China 48000 Holland 9600 

Spain 25000 USA 4000 

South Korea 21000 Israel 1500 

Italy 18500 India 3500 

Purpose of Glasshouse 

1. The purpose of growing crops under greenhouse conditions is to extend their cropping 

season and to protect them from adverse environmental conditions, such as extreme 

temperatures and precipitation, and from diseases and pests 

2. Greenhouse production normally requires a high level of technology to obtain adequate 

economic returns on investments 

Problems in glasshouses 

1. Normally value added crops are grown under protection most of them are laboure 

intensive and energy demanding during cold weather 

2. Normally high level of technology to obtain adequate economic returns 

3. Quality is a high priority for greenhouse crops, requiring much care in pest and disease 

management, not only to secure yields but cosmetic standard 

4. Continues cropping is practiced ,without a fallow--- it leads to the build-up of soil- borne 

and foliar pathogens 

5. This can generate chronic stress conditions ,which are conducive to some pests and 

diseases 

Factors Favorable to Pest and Disease Development: Well-grown and productive crops are 

generally less susceptible to diseases, but in many cases compromises have to be made between 

optimum conditions for economic productivity and conditions for disease and pest prevention. 

Well-fertilized and irrigated crops are, however, often more sensitive to pests, like aphids, 

whiteflies and leafminers. High host plant densities and the resulting microclimate are favorable to 

disease spread. Air exchange with the outside is restricted, so water vapour transpired by the 

plants and evaporated from warm soil tends to accumulate, creating a low vapour pressure deficit 

(high humidity). Therefore, the environment is generally warm, humid and wind-free inside the 

greenhouse. Such an environment promotes the fast growth of most crops, but it is also ideal for 

the development of bacterial and fungal diseases (Baker and Linderman, 1979; Fletcher, 1984; 

- 27 -


Jarvis, 1992), of insects vectoring viruses and of herbivorous insects. For bacteria and many fungi 

(causal agents of rusts, downy mildews, anthracnose, grey mould, etc.) Greenhouses are 

designed to protect crops from many adverse conditions, but most pathogens and several pests 

are impossible to exclude. Windblown spores and aerosols containing bacteria enter doorways 

and ventilators; soilborne pathogens enter in windblown dust, and adhere to footwear and 

machinery. Aquatic fungi can be present in irrigation water; insects that enter the greenhouse can 

transmit viruses and can carry bacteria and fungi as well. Once inside a greenhouse, pathogens 

and pests are difficult to eradicate. 

Problems in protected cultivation 

Greenhouses are designed to protect crops from many adverse conditions, but most 

pathogens and several pests are impossible to exclude as: 

1. Windblown spores and aerosols containing bacteria enter doorways and ventilators 

2. Soil-borne pathogens enter in windblown dust, and adhere to footwear and machinery 

3. Aquatic fungi can be present in irrigation water 

4. Insects that enter the greenhouse can transmit viruses and can carry bacteria and fungi as 

well 

5. Once inside a greenhouse, pathogens and pests are difficult to eradicate eg. leach 

Factors Stimulating Sustainable Forms of Crop Protection in Protected Cultivation: 

Protected cultivation is an extremely high-input procedure to obtain food and other agricultural 

products per unit of land, although inputs are the lowest when related to the yield per area. 

Among the factors stimulating sustainable forms of crop protection are the following: 

1. Consumer concern about chemical residues. 

2. Pesticide-resistance in pests and pathogens. 

3. Side-effects of chemical application are increasingly observed in old and new growing 

areas. 

4. Efficacy: Some pests and diseases are difficult – sometimes impossible – to control if an 

integrated approach is not adopted. 

Sometimes this can be achieved cheaply – in both economic and energetic terms – By 

means of correct crop and management practices. As mentioned before, the most damaging pests 

and many pathogens in greenhouses are polyphagous; although they are able to develop on many 

host plants, their negative effect on yield varies with host plant species and cultivar. The 

development of cultivars which are less susceptible to pests and diseases or that favour the 

activity of pest natural enemies is undoubtedly one of the most sustainable ways to control 

diseases in greenhouses and its potential for pests has been shown in a few but significant cases. 

REFERENCE 

• Baker, K.F. and Linderman, R.G. (1979) Unique features of the pathology of ornamental plants, 

Annual Review Phytopathology 17, 253–277. 

• Bates, M.L. and Stanghellini, M.E. (1984) Root rot of hydroponically grown spinach caused by 

- 28 -


Pythium aphanidermatum and P. dissotocum, Plant Disease 68, 989–991. 

• Carrai, C. (1993) Marciume radicale su lattuga allevata in impianti NFT, Colture Protette 22(6), 

77–81. 

• Castilla, N. (1994) Greenhouses in the Mediterranean area: Technological level and strategic 

management, Acta Horticulturae 361, 44–56. 

• Enoch, H.Z. (1986) Climate and protected cultivation, Acta Horticulturae 176, 11–20. 

• Fletcher, J.T. (1984) Diseases of Greenhouse Plants, Longman, London. 

• Germing, G.H. (1985) Greenhouse design and cladding materials: A summarizing review, Acta 

• Hanan, J.J., Holley, W.D. and Goldsberry, K.L. (1978) Greenhouse Management, Springer-Verlag, 

Berlin Horticulturae 170, 253–257. 

• Jarvis, W.R. (1992) Managing Diseases in Greenhouse Crops, American Phytopathological 

Society Press, St Paul, Minn. 

• Kennedy, R. and Pegg, G.F. (1990) Phytophthora cryptogea root rot of tomato in rock wool 

nutrient culture. III. Effect of root zone temperature on infection, sporulation and 

symptom development, Annals of Applied Biology 117, 537–551. 

• Reuveni, R. and Raviv, M. (1992) The effect of spectrally-modified polyethylene films on the 

development of Botrytis cinerea in greenhouse grown tomato plants, Biological 

Agriculture & Horticulture 9, 77–86. 

• Reuveni, R. and Raviv, M. (1997) Control of downy mildew in greenhouse-grown cucumbers using 

blue photoselective polyethylene sheets, Plant Disease 81, 999–1004. 

• Reuveni, R., Raviv, M. and Bar, R. (2008) Sporulation of Botrytis cinerea as affected by 

photoselective sheets and filters, Annals of Applied Biology 134, 417–424. 

• Tognoni, F. and Serra, G. (1989) The greenhouse in horticulture: The contribution of biological 

research, Acta Horticulturae 245, 46–52. 

• Wittwer, S.H. and Castilla, N. (1995) Protected cultivation of horticultural crops worldwide 

- 29 -


Soil Solarization for Biocontrol of Plant Pathogens 

Yogendra Singh 

Department of Plant Pathology, G.B.P.U.A.&T., Pantnagar-263145 (Uttarakhand) 

Several methods have been developed for the management of diseases incited by various 

plant pathogens, which include application of chemicals, breeding for disease resistance, 

sanitation, crop rotation, biological control and soil disinfestations. The need for different methods 

of plant disease management stems from the fact that usually none of them is perfect nor can 

anyone be used under all circumstances. Moreover, the life cycles of pathogens may vary in 

different crop systems, thus requiring different management strategies. Therefore, any new 

method of disease management is of value since it adds to our rather limited arsenal of control 

methods. This is particularly true with innovative non chemical approaches which are needed to 

replace hazardous chemicals. 

The concept of managing soil borne pathogens has now changed. In past, control of these 

pathogens concentrated on eradication. Later it has been realized that effective control could be 

achieved by interrupting the disease cycle, plant resistance or the microbial balance leading to 

disease reduction below the economic injury level, rather than absolute control. The integrated 

pest management concept encompasses many elements. In this context, soil solarization can play 

a significant role. Soil solarization is a non-chemical soil disinfestation method applied worldwide 

for the control of soil borne plant pathogens, weeds and nematodes. 

In Israel, extension workers and growers suggested that the intensive heating that occurs 

in mulched soil might be used for disease control. By mulching the soil with transparent 

polyethylene sheets in the hot season prior to planting, a team of Israeli workers developed a solar 

heating approach for soil disinfestation. Soil solarization is a method of controlling soil borne pests 

and pathogens by raising the temperature of the soil through application of transparent 

polyethylene sheet to a moist soil surface. With solarization vast possibilities for disease control 

are possible. Soil solarization as a disinfestations method, has potential advantages. It is a non 

chemical method which is not hazardous to the user and does not involve substances toxic to the 

consumer, to the host plant or to other organisms. In the right perspective it is less expensive than 

other methods. This technology can easily be transmitted to the farmers and can be applied in large 

areas manually and mechanically. It may have a long term effect, since effective disease control lasts 

for more than one season. This method has the characteristics of an integrated control, since physical, 

chemical and biological mechanisms are involved and because the control of a wide variety of pests is 

achieved. 

Use of this method has been reported to reduce the population of many soil borne pathogens 

including fungi bacteria and nematodes as well as weeds (Pullman et al.,1981; Katan et al., 1983; 

Barbercheck et al; 1986; Verma et al; 2005). Soil solarization applied singly or in combination with 

biocontrol agents or reduced doses of soil fumigants/fungicides has shown a remarkable 

- 30 -


destructive effect on most soil borne plant pathogens. 

Various terms like solar heating, plastic or polyethylene tarping, polyethylene or plastic 

mulching of soil have been used to describe this method. Since this method involves repeated 

daily heating at relatively mild temperatures, the term solar pasteurization has also been 

suggested. 

Principles 

Heat is used as a lethal agent for the control of plant pathogenic organisms through the 

use of transparent polyethylene soil mulches (tarps) for capturing solar energy. Polyethylene 

covering of soil induces green house effect and raises soil temperature. The following 

recommendations are made to bring about effective solar heating of soil: 

Transparent not black polyethylene should be used since it transmits most of the solar 

radiation that heats the soil. Black polyethylene, though it is greatly heated by itself, is less 

efficient in heating the soil than transparent sheet. 

Soil mulching should be carried out during the period of high temperatures and intense 

solar irradiation. 

Soil should be kept wet during mulching to increase thermal sensitivity of resting structures 

such as sclerotia, chlamydospores, etc. and to improve heat conduction. 

The thinnest possible polyethylene tarp (25-30 µm) is recommended, since it is both 

cheaper and more effective in heating, due to better radiation transmittance, than the 

thicker one. Polyethylene reduces heat convection and water evaporation from the soil to 

the atmosphere. As a result of the formation of water droplets on the inner surface of the 

polythene film, its transmissivity to long wave radiation is highly reduced, resulting in better 

heating due to an increase in its greenhouse effect. An ideal plastic mulch is that which is 

100% transparent to solar radiation and completely opaque to long wave radiation. This 

ideal mulch can increase soil temp. by 6-8 0 c over ordinary polyethylene. 

Since temperatures at the deeper soil layers are lower than at the upper ones, the 

mulching period should be sufficiently extended, usually 4 weeks or longer, in order to 

achieve pathogen control at all desired depths. 

The solar heating method for disease control is similar, in principle, to that of artificial soil 

heating by steam or other means. There are, however, important biological and technological 

differences: (i) With soil solarization there is no need to transport the heat from its source to the 

field. (ii) Solar heating is carried out at relatively low temperatures as compared to artificial heating; 

thus its effects on living and nonliving components are likely to be less drastic. Negative side 

effects observed with soil steaming such as phytotoxicity due to release of toxic products and a 

rapid soil reinfestation due to the creation of a biological vacuum have not been reported so far 

with solar heating. 

Absorption of solar radiation in different soils varies according to the colour, moisture, and 

- 31 -


texture of the soil. In general, the soil has high thermal capacity and is a poor heat conductor thus 

resulting in a very slow heat penetration in soil. The energy is lost from the soil in the form of long 

wave radiation through conduction, convection, and water evaporation. The principles of solar 

heating in polyethylene mulched soil were demonstrated by Waggoner et al., 1960. If thermal 

processes occurring in mulched soil are considered, then soil temperatures at the desired depth 

can be predicted. Mahrer, 1979 developed a one dimensional numerical model for such 

predictions. As per this model in wet, polyethylene mulched soil, increased temperatures are due 

primarily to the elimination of heat loss by evaporation and heat convection during the day time 

and partially to the green house effect (preventing part of the long wave radiation from leaving the 

ground). By predicting the temperatures at any depth of the mulched soil, the model enables us to 

select the suitable climatic regions and the time of year most adequate for solarization of soil, 

providing data on the heat sensitivity of the pathogens and their population density at various 

depths are available. Relative importance of type of mulching material, soil type, moisture and 

climatic factors can also be evaluated. Analysis of the spatial soil temperature regimes in mulched 

soil showed that heating at the edges of the mulch is lower than at the center, and that a narrow 

mulch strip is less efficient in heating than a wider one ( Mahrer and Katan, 1981). 

Mechanisms 

Reduction in disease incidence occurring in solarized soils, results from the effects exerted 

on each of the three living components involved in disease ie. host, pathogen, and soil microbiota 

as well as the physical and chemical environment which, in turn affects the activity and 

interrelationships of the organisms. Although these processes occur primarily during solarization, 

they may continue to various extents and in different ways, after the removal of the polyethylene 

sheets and planting. The most pronounced effect of soil mulching with polyethylene is a physical 

one, i.e. an increase in soil temperatures, for several hours of the day. However, other processes 

such as shifts in microbial populations, changes in chemical composition and physical structure of 

the soil, high moisture levels maintained by the mulch, and changes in gas composition of the soil, 

should also be considered while analyzing mechanisms of disease control. The following equation 

proposed by Baker (1968), for relating the various factors involved in biological control, should be 

adopted for this analysis: 

Disease severity =inoculum potential x disease potential, where inoculum potential is the energy 

available for colonization of a substrate (infection court) at the surface and disease potential is the ability 

of the host to contract disease. More specifically the equation becomes: 

Disease severity = (inoculum density x capacity) x (proneness x susceptibility), where 

capacity is the effect of the environment on energy for colonization, and proneness is the effect of 

the environment on the host. Of these four components, inoculum density (ID) is the one most 

affected by solarization either through the direct physical effect of the heat or by microbial 

processes induced in the soil. The other components, however (except for susceptibility which is 

- 32 -


genetically determined) might also be affected. 

Whenever microorganisms are subjected to moist heat, at temperatures exceeding the 

maximum for growth, their viability is reduced. The thermal death rate of a population of an 

organism depends on both the temperature level and exposure time, which are inversely related. 

At a given temperature and time of exposure, mortality rate is related to the inherent heat 

sensitivity of the organisms and to the prevailing environmental conditions. In general, populations 

of soil borne fungal pathogens are drastically reduced at temperatures of 40-50 0 C, exposure time 

ranging from minutes to hours for the higher temperatures, and up to days for the lower 

temperatures. The response of the population to elevated temperatures depends on propagule 

type, age and on environmental factors like pH, presence of ions etc. Presence of moisture is a 

crucial factor since microorganisms are much more resistant to heat under dry conditions. The 

effect of water can be explained by the dependence of the heat stability of proteins on hydration. In 

the presence of water less energy is required to unfold the peptide chain of proteins, resulting in a 

decreased heat resistance. Heating dry soils is therefore not effective in pathogen control (Katan 

et al., 1976). 

Microbial processes, induced in the soil by solarization, may contribute to disease control, 

since the impact of any lethal agent in the soil extends beyond the target organisms. If induced by 

solarization, biological control may affect the pathogen by increasing its vulnerability to soil 

microorganisms or increasing the activity of soil microorganisms toward pathogen or plant, which 

will finally lead to a reduction in disease incidence, pathogen survivability, or both. Thus both short 

and long term effects might be expected. Biological control may operate at any stage of pathogen 

survival or disease development during or after solarization, through antibiosis, lysis, parasitism, or 

competition. 

Disease Management 

Soil solarization has been demonstrated to control diseases caused by many fungal 

pathogens such as Rhizoctonia solani, Fusarium spp., Pythium spp., Phytophthora spp., 

Verticillium spp., Sclerotium rolfsii etc., bacterial pathogens such as Agrobacteria and 

Pseudomonas and many species of nematodes in many crops both under field conditions and 

plastic houses (Katan et al., 1983; Abdul et al., 1995; Raoof and Rao,1997; Chellemi et al., 1994). 

The method has also been used to control many species of nematodes. Diseases caused by 

Meloidogyne spp., Heterodera spp. etc.have been successfully controlled by soil solarization (Rao 

and Krishnappa, 1995; Grinstein et al., 1995). 

Weed Control 

Solarization results in an effective weed control lasting in some cases for more than two or 

three seasons (Abdel Rahim et al., 1988; Verma et al., 2005). In general most of the annual and 

many perennial weeds have been found to be effectively controlled. Weed control may be effected 

by direct killing of weed seeds by heat, indirect microbial killing of seeds weakened by sublethal 

- 33 -


heating, killing of seeds stimulated to germinate in the moistened solarized soil, and killing of 

germinating seeds whose dormancy is broken in the heated soil. Volatiles may also play a role in 

weed control (Horowitz, 1980; Rubin and Benzamin, 1981). 

Increased growth response 

Plant growth in solarized infested soil is enhanced as compared to untreated, infested soil 

as a result of pathogen control but solarization of soil which is apparently free of known pathogens 

often results in improved plant growth. This could be attributed to increased micro and macro 

nutrients in soil solution, elimination of minor or unknown pathogens, destruction of phytotoxic 

substances in the soil, release of growth regulator like substances, and stimulation of mycorrhiza, 

PGPR, and other beneficial microorganisms. The effect of soil solarization on earthworms 

population has not received much attention but it is thought that they retreat to lower depths to 

escape the effect of soil heating. The increased growth response of plants in solarized soil is a well 

documented phenomenon and has been verified both in green house experiments and under field 

conditions (Broadbent et al, 1977; Katan, 1987; Chen et al., 1991; Singh, 2008). 

Combining solarization with other methods 

Despite the successes achieved with solarization when used singly this method may be 

usefully aided by combination with other methods of disinfestation. As soil solarization is 

dependent upon local climatic conditions, sometimes even during conducive periods of the year, 

local weather conditions will not permit an effective solarization treatment. Therefore, we must 

come up with integrated uses of solarization in order to increase the predictability of the treatment 

and thus make it more acceptable to growers. Combining solarization with pesticides, organic 

amendments, or biocontrol agents improves disease control. Whenever a pathogen is weakened 

by heating, even reduced dosages might suffice for improved control combining with biocontrol 

agents, organic amendments, etc. 

Low application rates of fungicides, fumigants or herbicides have been successfully 

combined with soil solarization to achieve better pest control (Hartz et al, 1993).Simultaneous 

application of chemicals and tarping the soil for solarization has been shown to increase the 

effectiveness of both the methods because of synergism (Ben –Yephet et al. 1988; Tjamos, 1984). 

Reduced doses of metham-sodium (12.5 or 25 ml/m 2 ) applied singly or in combination with soil 

solarization synergistically destroyed V. dahliae and F. oxysporum f.sp. vasinfectum in a naturally 

infected cotton field. The synergism was attributed to the weakening effect induced by increased 

soil temperatures along with the toxicity of the chemical. The combination also reduced to one 

week the time needed to kill sclerotia of Sclerotinia sclerotiorum in the top 10 cm of soil in a lettuce 

field and reduced apothecia production. Carbendazim has shown slower degradation rates after 

solarization, possibly because of changes in the populations of soil microorganisms after 

solarization. 

Solarization may also be combined with application of crop residues, green and farm yard 

manures. There is increasing evidence that these materials release volatile compounds in the soil 

- 34 -


that kill pests and help stimulate the growth of beneficial soil organisms (Deadman et al, 2006; 

Gamliel and Stapleton, 1993). 

Soil solarization has also been successfully combined with biological control. The use of 

Trichoderma harzianum with solarization in fields infested with Rhizoctonia solani has been shown 

to improve disease control while delaying the buildup of inoculum (Chet et al, 1982). Greenberger 

et al, 1987 concluded that solarized soils are frequently more suppressive and less conducive to 

certain soil borne pathogens than non-solarized soils. An increase in population of green 

fluorescent pseudomonads along with an increase of Penicillium and Aspergillus spp. following 

solarization has been demonstrated (Stapleton and DeVay, 1982). 

Limitations 

Solarization involves limitations, difficulties and possible negative effects. 

It is weather dependent and can only be used in regions where the climate is suitable (hot) and 

the soil is free of crops for about one month or more at a time of tarping with PE sheets. The 

soil heating effect may be limited on cloudy days. Wind or air movement across the plastic 

sheet rapidly dissipates the trapped heat. Strong winds may also lift or tear the sheets. 

It is too expensive for some crops and ineffective in the control of certain diseases 

Heat tolerant pathogens might develop after repeated application, though selection for 

tolerance to lethal agents is not likely to develop with disinfestation methods which are not 

target specific 

Another possibility would be an increase in pathogen population due to a harmful effect on its 

antagonists 

Future Thrust 

The economic profitability of disease control depends on the additional income obtained 

and the cost of application. The additional income obtained through solarization far 

exceeds with high-value crops but with other crops situation may not be the same. There 

are several possibilities for reducing the cost of mulching: (a) Used polyethylene may be as 

effective as the new, thus reducing the cost to nearly zero (b) Reusing the polyethylene, 

providing it is durable (c) If required during the growing season, durable sheets may be 

used for both solarization and mulch (d) The production of thinner polythene sheets (of an 

adequate strength) will reduce the amount needed per hectare. 

 

Development in plastic technology may provide improved and economical mulching 

materials with greater heating efficiency and increased durability. This may include 1) 

Biodegradable plastic that decomposes in the natural environment 2) Further development 

of polyethylene recycling processes 3) Developing economic, novel plastic or other 

materials more efficient than polythene in trapping solar energy, thus reducing our 

dependence on climate and making this available to cooler regions 4) Possibility of plastic 

- 35 -


material that can be sprayed on the soil, instead of polyethylene mulching, should be 

explored. At present, biodegradable plastic products available in the market are more 

expensive than traditional plastics. Their cost needs to be reduced to make them 

economical. 

REFERENCES 

• Abdel Rahim, M. F., Satour, M. M., Mickail, K.Y. and El Eraki, S. A. (1988). Effectiveness of soil 

solarization in furrow irrigated Egyptian soils. Plant Dis.. 72: 143-146. 

• Barbercheck, M.E.and von Broembsen, S.L (1986). Effect of soil solarization on plant parasitic 

nematodes and Phytophthora cinnamomi in South Africa.Plant Dis. 70:945-950. 

• Broadbent, P, Baker, KF, Franks, N and Holland, J. 1977. Effect of Bacillus spp. on increased 

growth of seedlings in steamed and in non treated soil. Phytopathology. 67: 1027-1034. 

• Chellemi, D.O.., Olson, S.M. and Mitchell, D. J. (1994). Effect of soil solarization and fumigation on 

survival of soil borne pathogens of tomato in Northern Florida. Plant Dis. 78: 1167-1172. 

• Chen, Y., Gamliel, A., Stapleton, J. J. and Aviad, T. (1991). Chemical, physical and microbial 

changes related to plant growth in disinfested soils. In: Soil Solarization. Katan, J. and 

De Vay, J. E. (eds.) CRC Press, Inc., Boca Raton, FL. pp. 103-129. 

• Chet, I, Elad, Y, Kalfon, A, Hadar, Y and Katan, J. 1982. Integrated control of soilborne and 

bulbborne pathogens in iris. Phytoparasitica. 10:229. 

• Deadman, M, Al Nasani, H and Al Sa’di, A. 2006. Solarization and Biofumigation reduce Pythium 

aphanidermatum induced damping off and enhance vegetative growth of green house 

cucumber in OMAN. Journal of Plant Pathology. 88: 335-337. 

• Gamliel, A and Stapleton, J. 1993. Effect of chicken compost or ammonium phosphate and 

solarization on pathogen control, rhizosphere organisms, and lettuce growth. Plant 

Disease. 77:886-891. 

• Grinstein, A., Kritzman, G., Hetzroni, A., Gamliel, A. Mor, M. and Katan, J. (1995). The border 

effect of soil solarization. Crop Protect. 14: 315-320. 

• Hartz, T, DeVay, J and Elmore, C. 1993. Solarization is an effective soil disinfestations technique 

for strawberry production. Hort. Sci. 28(2): 104-106. 

• Horowitz, M. 1980. Weed research in Israel. Weed Sci. 28: 457-460. 

• Katan, J, G Katan, J, Greenberger, A, Alon, H and Grinstein, A. 1976. Solar heating by 

polyethylene mulching for the control of diseases caused by soil-borne pathogens. 

Phytopathology. 66: 683-688. 

• Katan, J. (1987). Soil solarization. In: Innovative approaches to plant diseases control. Chet, I. 

(ed.). John Wiley & Sons New York. pp 77-105. 

• Katan, J., Fishler, G. and Grinstein, A. (1983). Short and long term effects of soil solarization and 

crop sequence on Fusarium wilt and yield of cotton in Israel. Phytopathology. 73:1215- 

1219. 

• Mahrer, Y. 1979. Prediction of soil temperature of a soil mulched with transparent polyethylene. J. 

Appl. Meteorol. 18:263-267. 

• Mahrer, Y. and Katan, J. 1981. Spatial soil temperatures regime under transparent polyethylene 

mulch-numerical and experimental studies. Soil Sci. 131: 82-87. 

- 36 -


• Pullman, G.S., Devay, J.E., Garber, R.H. and Weinhold, A.R. (1981) Soil solarization on 

Verticillium wilt of cotton and soil borne population of Verticillium dahliae, Pythium spp., 

Rhizoctonia solani and Thielaviopsis basicola. Phytopathology. 71:954-959. 

• Rao, V. K. and Krishnappa, K. (1995). Soil solarization for the control of soil borne pathogen 

complexes with special reference to M. incognita and F. oxysporum f.sp. ciceri. Indian 

Phytopath. 48: 300-303. 

• Raoof, M. A. and Nageshwar Rao, T. G. (1997). Effect of soil solarization on castor wilt. Indian J. 

Plant Protect. 25: 154-159. 

• Rubin, B and Benjamin, A. 1981. Solar sterilization as a tool for weed control. Abstr. Weed Sci. 

Soc. Am. p.133. 

• Singh, Y. (2008). Effect of soil solarization and biocontrol agents on plant growth and 

management of anthracnose of sorghum. Internat. J. Agric. Sci. 4: 188-191. 

• Tjamos, EC. 1984. Control of Pyrenochaeta lycopersici by combined soil solarization and low dose 

of methyl bromide in Greece. Acta Hortic. (The Hauge). 152: 253. 

• Verma, R. K. Singh, Y., Soni, K. K. and Jamalluddin (2005). Solarization of forest nursery soil for 

elimination of root pathogens and weeds. Indian J. Trop. Biodiv. 13: 81-86. 

• Wagonner, PE, Miller, PM and DeRoo, HC. 1960. Plastic mulching principles and benefits. Conn. 

Agric. Exp. Stn. Bull. 623, 44 pp. 

- 37 -


Microbial Interactions in Phyllosphere and Rhizosphere 

P.C. Srivastava 

Department of Soil Science, G.B.P.U.A.&T., Pantnagar-263145 (Uttarakhand) 

Both positive and negative interactions take place between microbes and also between 

microbes and plants. The rhizosphere is a zone of predominantly commensal and mutualistic 

interactions between plants and microbes. The aerial surfaces of plants provide habitats for largely 

commensal microbes. On the negative side, certain viruses, bacteria, and fungi cause plant 

diseases that can result in great economic losses and even severe food shortages. 

Some of the positive interactions among plants and microbes are: 

 

 

 

Synergistic interactions which include rhizosphere, rhizoplane, phyllosphere and 

spermosphere. 

Mutualistic interactions which include root nodule interactions, leaf nodule interactions and 

mycorrhizal interactions. 

Parasitism is the only negative interaction among the plant and the microbes. 

Spermosphere 

It is the volume of soil that surrounds a seed with increased microbial activity around a 

germinating seed because of the nutrients leaked into the soil by the germinating seeds. While 

most of the microbes are harmless, some may be positively beneficial and some of them may be 

pathogenic. Spermosphere organisms forming the normal flora around a germinating seed have 

some beneficial effects through biological products like growth hormones. Germinating seeds 

excrete certain chemicals which may influence both the quality and quantity of microbes in the 

vicinity of the seed. 

When a seed is sown in soil, certain interactions take place between the seed-borne 

microflora and the soil-borne microflora which influence the quality of the spermosphere at that 

condition. When the seed is pre-treated with a fungicide or with any other biological agent, this 

influences such interactions to a great extent. For example, the fungicide may totally alter the 

seed microflora by inhibiting some fungal flora and increasing some other bacterial flora. This 

could also influence the nature of microflora that is about to colonise the rhizosphere. Thus, by 

manipulating the spermosphere, one changes the rhizosphere also. When a seed carrying a 

natural or altered load of microbes is sown, certain microbes are activated and others are 

suppressed. Usually, the microbes that are artificially loaded onto the seed are more dominant 

flora of the seed and this enables the scientists to beneficially alter the spermosphere of 

a particular seed, as in Rhizobium, Azotobacter and Azospirillum coated seeds. These organisms 

get established on the root surface of the germinating seed and benefit the plant. 

Along with spermosphere microflora, the soil-borne flora may also get activated and 

compete with the former (for nutrition and space). The chemicals excreted by the germinating seed 

decide the final quality and quantity of the microflora around the seed. Usually microbes move 

- 38 -


from the spermosphere to the rhizosphere within three days. Various chemical treatments of the 

seed definitely change the rhizosphere micro flora of the seedling thus indicating the plant-rootmicrobes 

interactions in the soil through the seed. When the seed is internally or externally 

infected by certain pathogenic microorganisms (smut spores), this definitely alters the quality and 

quantity of the spermosphere and rhizosphere microflora (again through competition). When such 

a suspected seed is pre-treated with plant protection chemicals, the competition is eliminated as 

the pathogen gets killed and hence the seed gets the harmless microbes. When the seed is pretreated 

with organic manure (cow dung) having usual saprophytes present in the manure there is 

competition between pathogens and non-pathogens saprophytes from the organic manure and 

depending on the efficiency of one group, one is suppressed and gets eliminated. For example, a 

seed-borne pathogen of cotton (Xanthomonas campestris pv malvacearum ) is controlled when 

the seed is pretreated with cow dung slurry. Further, when a pathogen infected seed is sown in 

unsterile and sterile soil, there is intense spermospheric effect (enough to suppress the pathogen) 

in the former whereas in the latter case, pathogen becomes highly virulent in the absence of other 

organisms. 

Rhizosphere 

Rhizosphere is the region where soil and roots of the plants make contact. Rhizosheath is 

a modification of rhizosphere, characterized by a relatively thick soil cylinder that adheres to the 

plant roots. When the roots are cleaned of all the soil particles adhering to it and then plated, 

microorganisms can be seen developing indicating that there are certain microbes intimately 

associated with the root surface. Some fungi inhabit the root surface in a mycelial state, 

e.g.Cephalosporium, Trichoderma and Penicillium. Specific bacteria also get embedded on the 

surface of the root with the help of mucilaginous external layer normally present in the actively 

growing root system. 

Effect of Plant Root on Microbial Populations 

The structure of the plant root system contributes to the establishment of the rhizosphere 

microbial population. The interactions of plant roots and rhizosphere microorganisms are based 

largely on interactive modification of the soil environment by processes such as water uptake by 

the plant and release of organic chemicals by the roots. The influence of the plant root on the 

microflora is governed by root exudates, physical and chemical factors in the soil. 

Effect of root exudates 

This is the major factor that governs the microflora of the rhizosphere. The root exudates 

include: Simple sugars such as glucose and fructose Di, tri and oligo saccharides . All common 

amino acids - alanine, serine, leucine, valine, glutamic and asparitic acids. Of these, glutamine and 

asparagine are produced in large amounts. Other compound are vitamin like thiamine and biotin, 

nucleotides, flavones and auxins. All these root exudates have an effect on the rhizosphere 

microflora. Some of the root exudates like the amino acids promote the growth of microflora in the 

- 39 -


rhizosphere. Some nitrogen fixers such as Azospirillum, Azotobacter paspali use the root exudates 

as the energy source for significant nitrogen fixation. Root exudates containing toxic substances 

such as glycosides and hydrocyanic acid may inhibit the growth of pathogens. One of the 

attributes of root exudates is the possible role they play in neutralising the soil pH and altering the 

microclimate of the rhizosphere through liberation of water and CO 2 , such changes may influence 

infections of roots by pathogenic fungi. 

Effect of plant growth on rhizosphere microflora 

The rhizosphere microflora may undergo successional changes as the plant grows from 

germination to maturity. During plant development, a distinct rhizosphere succession results in 

rapidly growing, growth factor-requiring, opportunistic microbial population. These successional 

changes correspond to changes in the materials released by the plant root to the rhizosphere 

during plant maturation. Initially, carbohydrate and mucilaginous exudates from plant roots 

stimulate the growth of microorganisms rapidly within the grooves on the root surface and within 

the mucilaginous sheath (rhizoplane). After the plant matures, autolysis of some of the root 

materials takes place and simple sugars and amino acids are released into the soil. This further 

stimulates the growth of bacteria with high intrinsic growth rates, e.g. Pseudomonas. As a result of 

these effects, the rhizosphere microflora consists of higher proportion of gram negative rods and a 

lower proportion of gram positive rods, cocci and pleomorphic forms. A relatively higher proportion 

of motile, rapidly growing bacteria are also seen. 

Alteration of rhizosphere microflora 

Soil amendments 

This refers to the artificial addition of amendments and chemical fertilisers supplying N, P 

and K. This depends on the rhizosphere: soil (R:S) ratio and also on the nutritional content of the 

chemicals in the soil. 

Foliar application of nutrients 

Normal translocation of photosynthates from leaves to roots does not affect the microflora. 

However, when foliar application of antibiotics, growth regulators, pesticides and inorganic 

nutrients is carried out, a small amount is being released as root exudates and this can either 

promote the growth of the present microflora or change the microflora to some extent. 

Artificial inoculation 

This is done on seed or soil with preparation containing live microorganisms especially 

bacteria (bacterisation). This provides an easier way for the establishment of the desired microbes 

to the rhizosphere. This is because as the seed is coated with the live microorganisms, as soon as 

the root evolves, the colonising of the root takes place and establishment of the other microbes is 

also made possible. Microbial seed inoculants generally used are Azotobacter, Beijerinckia, 

Rhizobium or P solubilising microorganisms. 

- 40 -


Effect of Rhizosphere Microbial Population on Plants 

The microorganisms have a marked influence on the growth of plants. Plant growth may be 

impaired due to the absence of appropriate rhizosphere microflora. The microbial population affect 

the plant growth in various ways: 

Promotion of growth 

This is brought about by the release of growth factors like auxins and gibberellins that 

promote plant growth. The organisms which release these growth factor include Arthrobacter, 

Pseudomonas and Agrobacterium. The production of indole acetic acid (IAA), a plant growth 

hormone by the certain group of microorganisms increases the rate of seed germination and 

development of root hairs. 

Neutralisation of toxic substances 

This is seen in the case of plants that grow in flooded sediments e.g. rice. In this case, 

there is production of hydrogen sulphide generated by the sulphate reduction pathway. This 

hydrogen sulphide is toxic to the plant roots, and this is neutralised by the bacteria Beggiatoa. This 

is a microaerophilic, catalase negative, sulphide oxidizing filamentous bacterium. This acquires the 

oxygen and catalase enzyme from the rice plant and aids in the oxidation of toxic H 2 S to harmless 

S or SO -2 4 , thus protecting the rice roots. 

Allelopathic effect 

Some substances by the microbes can have an antagonistic effect too. Some 

extracellular products of certain microorganisms lead to the growth of other kinds of 

microorganisms that can provide a better rhizosphere microflora. These extracellular products can 

also inhibit the growth of pathogens, thus protecting the plant roots from getting damaged. 

Nutrient recycling 

The nutrients in the soil are made available to the plants by mobilisation of the nutrients, by 

fixing it in soil. Sometimes, the nutrients are made unavailable by immobilisation. For example, 

microorganisms produce extracellular amino acids, vitamins, etc. using the nutrients and N fixation 

process. They make N available to plants as nitrates or other inorganic forms, e.g. Rhizobium and 

Azotobacter. Similarly, sulphur oxidisers make sulphur available as sulphates, e.g. Desulfovibrio. 

Phosphorous is made available as phosphates by the production of acids by the microflora. 

Siderophore production is another important characteristic feature of rhizosphere microflora. Many 

microorganisms respond to a fall in the availability of iron in soil by producing extracellular low 

molecular weight iron transporting agents known as siderophores. These siderophores selectively 

complex with iron and supply Fe to the living cell. They also act as growth factors or antibiotics. 

For example, Pseudomonas fluorescence (one strain produced a siderophore compound 

‘pseudobactin’ inhibits the growth of a pathogen Eewinia carotovora by chelating iron in the vicinity 

of the pathogen to reduce the disease severity. Thus, microorganisms increase the recycling and 

solubilisation of mineral nutrients and making it available to plants. The abundant growth of 

- 41 -


microbial population in the rhizosphere can sometimes create a deficiency of required minerals for 

the plants, e.g. bacterial immobilisation of Zn and oxidation of Mn cause the plant diseases 'little 

leaf' of fruit trees and ' gray speck' of oats. Nitrogen is immobilised in the form of microbial protein 

and some may be lost to the atmosphere by denitrification. 

Phyllosphere 

Phyllosphere refers to the quality and quantity of microorganisms found on the surface of 

the leaves and differs with the age of .the plant, leaf area, morphology, atmospheric factors 

(temperature, humidity,etc.). Growing seasons may also influence the phyllosphere microflora. It 

increases and reaches the maximum in autumn when the leaves severe. 

The position of the leaves also plays a role in determining the microflora. Leaves at the 

lower levels harbour more microorganisms since they are sheltered and get more nutrients from 

the raindrops from upper levels. Plant leaves are exposed to dust and air currents resulting in the 

establishment of a typical flora on their surface aided by cuticle, waxes and appendages (thorns, 

spikes) which help in the anchorage of microbes. The leaf diffusates/ exudates promote/ deter the 

growth of microbes on their surface. The principal nutritive factor in the leaf are amino acids, 

glucose, fructose and sucrose. The dominant microorganisms in a forest vegetation are the 

nitrogen fixing bacteria such as Beijerinckia and Azotobacter. Other genera like Pseudomonas, 

Enwinia, Sarcina have been encountered in the phyllosphere. Under damp conditions, some 

leaves may harbour cyanobacteria like Anabaena, Calothrix, Nostoc and Tolypothrix on their 

surfaces. Some of the fungi and actinomycetes encountered are Cladosporium, Alternaria, 

Cercospora, Helminthosporium, Mucor and Streptomyces species. 

Characteristic Features of Phyllosphere Microflora 

Leaf surface microbes may perform an effective function in controlling the spread of air 

borne microbes inciting plant diseases. Presence of a fungal spore on the surface of leaves incite 

the formation of a chemical substance referred to as phytoalexin which are active in host- defence 

mechanisms. Resistance to disease causing microbes has also been attributed to fungistatic 

compounds secreted by leaves such as malic acid from leaves of Cicer arietinum. The name 

‘elicitor’ has been commonly used to denote the compounds which induce the synthesis 

of phytoalexins. These are biotic elicitors such as polysaccharides from fungal cell walls, lipids, 

microbial enzymes and polypeptides. Abiotic elicitors are heavy metal salts, detergents, UV light, 

etc. Epiphytic microbes are known to synthesise indole acetic acid. PhylIosphere bacteria are 

often pigmented due to direct solar radiation. Pink-pigmented facultative methylotrophs are 

common in the phyllosphere. Bacteria can serve as ice nucleators, promoting frost damage to 

plants. Genetically modified Pseudomonas syringaea lacks a membrane protein that promotes 

nucleation. Inoculating crops with this organism can lower the temperature at which frost damage 

occurs. Azolla-Anabaena symbiosis is a N fixing association where cyanobacteria live on leaf 

surface. Any change in phyllosphere affects plant growth which in turn affects the physiological 

- 42 -


activity of root system. Such changes in the root result in an altered pH and spectrum of chemical 

exudation causing a change in rhizosphere microflora. Thus , there is a link between phyllosphere 

microflora and rhizosphere microflora. There is a continuous diffusion of plant metabolites from the 

leaves which support the microbial growth and in turn these microbes protect the plant from 

pathogens. 

Positive Interactions of Plants and Microbes 

Fungal mutualistic interactions are pronounced in plants. 

Leaf Nodule 

Symbiotic association of certain bacterial endophytes with leaves of certain plants (usually 

belonging to the families Rubiaceae and Myrsinaceae) leads to the formation of nodule like 

structures on the leaves. The plants Psychotria, Pavetta, Chomelia have received considerable 

importance as leaf nodule producing plants. Isolates of bacteria that have gained importance in 

formation of leaf nodules are Mycobacterium rubiacearum, Mycoplana rubra, Flavobacterium 

species, Bacterium rubiacearum, Phyllobacterium rubiacearum and Klebsiella rubiacearum. There 

are not many advantages (for the plants) resulting from this sort of mutualistic interactions apart 

from the fact that the bacterial partners secrete phytohormones (cytokines) for the growth of the 

plants. The plants definitely provide shelter and photosynthates for the survival of their bacterial 

partners. Since they form a stable phyllospheric microflora with the plants, these bacterial 

partners may also prevent the entry of pathogenic spores from entering through the leaves and 

establishing themselves. 

Mycorrhiza 

They occur on almost all terrestrial plants though not as specific as N fixing symbiosis. 

Thus a plant may have several mycorrhizae that can form symbiosis with its roots. Extent of 

symbiosis depends on soil fertility. High soil fertility leads to low mycorrhizal infection and poor 

symbiosis and vice versa. Roots supply carbohydrates to the fungi which absorb nutrients form the 

soil and supply them to the crop. 

Ectomycorrhiza 

Ectomycorrhizal symbiosis is a mutually beneficial union between roots of higher plants 

and the typical ectomycorrhizal fungi are basidiomycetes (Agaricus), ascomycetes or 

phycomycetes members. Ectomycorrhizae have poor competitive saprophytic ability hence they 

have a tough time competing with other microbes in the soil. The fungal hyphae on the exterior of 

the roots usually serve as an extension of roots and store large amounts carbohydrates 

Endomycorrhiza 

In this case, the fungal hyphae penetrate the host root cells. They are quite common 

among the Ericaceae and Orchidaceae members of higher plants as well as fruit trees like citrus, 

coffee, rubber, etc. 

Vesicular-arbuscular mycorrhiza (VAM) fungi: These are geographically ubiquitous and are 

- 43 -


commonly found in association with agricultural crops, shrubs, tropical tree species and some 

temperate trees. Their nutritional requirements are not specific. VAM associations are formed by 

non-septate Zygomycetes and Phycomycetes fungi. Some examples are Glomus, Gigaspora, 

Acaulospora, Entrophospora and Scutellospora. Glomus is the most common fungus. The fungi 

are obligate biotrophs and do not grow on synthetic media. Phosphate transfer possibly occurs 

across living membranes of the host and the fungus via arbuscles. VAM fungi interact with other 

soil microbes like the free-living and symbiotic N fixers and P solubilisers to improve their 

efficiency for the biochemical cycling of nutrients to the host plants. 

Negative Interaction between Plants And Microbes 

Parasitism is the only negative interaction between the plants and microbes. As parasites, 

the microbes, like bacteria, fungi, viruses and algae, cause infections in the host plant leading the 

development of disease and loss of commercial value in case the host plant is an agricultural crop. 

To cause the disease, the parasite must accomplish two important things: 

1. It must enter the host plant. 

2. It must establish itself at the specific target site within the plant. 

3. The parasite must overcome the plant defence mechanisms and causes the disease. 

These interactions are either biotrophic to obtain nutrition from the plant for a long time 

without instantaneous killing of the plant or necrotrophic wherein the pathogen kills the host and 

obtains the nutrition from the dead tissues. 

REFERENCES 

• Fokkema, N. J., and B. Schippers. 1986. Phyllosphere vs rhizosphere as environments for 

saprophytic colonization. p. 137-159. In N. J. Fokkema and J. Van den Heuvel (ed.), 

Microbiology of the phyllosphere. Cambridge University Press, London, UK. 

• Mercier, J., and S. E. Lindow. 2001. Field performance of antagonistic bacteria identified in a 

novel laboratory assay for biological control of fire blight of pear. Biol. Control 22:66- 

71. 

• Morris, C. E., and L. L. Kinkel. 2002. Fifty years of phylosphere microbiology: significant 

contributions to research in related fields, p. 365-375. InIn S. E. Lindow, E. I. Hecht- 

Poinar, and V. Elliott (ed.), Phyllosphere microbiology. APS Press, St. Paul, Minn. 

• Andrews, J. H., and R. F. Harris. 2000. The ecology and biogeography of microorganisms on plant 

surfaces. Annu. Rev. Phytopathol. 38:145-180. 

• Beattie, G. A., and S. E. Lindow. 1999. Bacterial colonization of leaves: a spectrum of strategies. 

Phytopathology 89:353-359. 

- 44 -


Exploiting Nematophagus Fungi for the Management of Root-Knot 

Nematodes 

Rakesh Pandey 

Microbial Technology & Nematology, CSIR-Central Institute of Medicinal and Aromatic Plants, P.O.CIMAP, 

Lucknow - 226 015 (UP) 

An unseen, underground and hidden, enemy pest, which silently spread from nursery to 

nursery, and field-to-field, attacking most of the agricultural crops including medicinal and aromatic 

crops throughout the world is plant parasitic nematode. Plant parasitic nematodes are microscopic 

roundworms that live in diverse habitats viz. soil and plant tissues. Due to obligate nature of these 

parasites, nematodes attack the root or other plant parts in soil like bulb and tubers, and interrupt 

the uptake of water and nutrients by plants. The annual global loss in agriculture due to damage 

by variety of phytonematodes can be estimated as more than US$125 billion worldwide. Besides 

direct damage some plant parasitic nematodes transmit plant viruses and also interact with fungi 

and bacteria to enhance damage several folds. Organic soil amendments have been reported by a 

large number of researchers to manage nematode problem but the large quantities required per 

unit area renders the strategy largely inapplicable in large scale farming enterprises. The assault 

on the environment through the use of chemical nematicides as well as unreliable results from 

cultural methods of nematode management has necessitated the search for sustainable, effective 

and environmentally acceptable nematode management options. Rhizosphere is the site of 

intensive interaction between plant and other rhizospheric microbes. Rhizospheric flora has 

reportedly immense potential for soil and plant health. But this all depend on the density and types 

of microbes. Useful microbes like PGPR, mutualistic fungi, and other nematode antagonists 

disfavor the multiplication and development of phytonematode population in soil, enhancing the 

growth/yield of the crop. For example when nematode population density reaches a certain level, 

host crop yields suffer greatly as few host plant support faster multiplication of nematodes and 

others do not. For sustainable cultivation of medicinal and aromatic plants, effective management 

of plant parasitic nematodes is essential. As my group begins to develop a better understanding of 

the complex ecologies of soils and agricultural ecosystems, more strategies for exploitation of 

microbes for the management of plant parasitic nematodes will be developed. The suggested 

characteristics of microbes for nematode management and better crop health include host 

specificity, easy in vitro/in vivo manipulation, mass production and easy dissemination with 

standard equipments. Besides it should also have potential for establishment and recycling, longer 

shelf life providing control for extended periods and should not be harmful to the environment. 

Following types of Nematophagus fungi are utilized to manage the population of plant parasitic 

nematodes. 

‣ Nematode Trapping Fungi 

o 

Adhesive Networks 

- 45 -


o Adhesive Knobs 

o Nonconstricting Rings 

o Constricting Rings 

o Adhesive Conidia 

‣ Zoosporic Fungi 

‣ Parasites of Nematode Eggs 

Each group of Nematophagus fungi utilizes a different type of structure to adhere or attack 

the nematodes. For nematode trapping fungi, this is thought to be mainly a passive activity with 

the fungus waiting for the nematode to pass by and become stuck to knobs, networks, or conidia. 

The fungi which form rings have been shown to form more rings in the presence of nematodes 

than in their absence. Fungal hyphae then penetrate the nematode body and utilize it for their 

nutrition. 

Major fungi which are involved to manage nematode population are Trichoderma 

harzianum, Hirsutella rhossiliensis, Hirsutella minnesotensis, Verticillium chlamydosporum, 

Arthrobotrys dactyloides, Paceilomyces lilacinus, Myrothecium verrucaria etc. Few bacteria are 

also reported against phytonematodes are: Pasteuria penetrans (formerly known as Bacillus 

penetrans), Bacillus thuringiensis (available in insecticidal formulations) and Burkholderia cepacia, 

Pseudomonas fluorescens, Bacillus subtilis, Bacillus chitinosporus etc. 

It is clear that there is a wide range of organisms that feed on, kill, or repel nematodes. 

These organisms are most effective, and are found most commonly, in healthy, well-managed soil. 

- 46 -

Introduction 


Soil Fertility in Organic Farming System 

D.K. Singh and Manisha Rani 

Department of Agronomy, G.B.P.U.A.&T., Pantnagar- 263 145 (Uttarakhand) 

Organic farming has expanded rapidly in recent years and is seen as a sustainable 

alternative to chemical-based agricultural systems (Stockdale et al., 2001; Biao et al., 2003; Avery, 

2007). Its annual growth rate has been about 20% for the last decade (Lotter, 2003), accounting 

for over 31 million hectares (ha) and generating over 26 billion US dollars in annual trade 

worldwide (Yussefi, 2006). Nutrient management in organic farming systems is often based on soil 

fertility building via nitrogen (N) fixation and nutrient recycling of organic materials, such as 

farmyard manure and crop residues, with limited inputs from permitted fertilizers (Gosling and 

Shepherd, 2005). Although organic farming has been criticized for relying on the build-up of soil 

phosphorus (P) and potassium (K) by past fertilization before converting to its acceptance and 

popularity are growing due mostly to environmental and health related concerns (Biao et al., 2003; 

Galantini and Rosell, 2006). A recent polling of residents of Ontario, Canada reveals that more 

than half think organic food is more nutritious; two-thirds believe organic food is safer than 

conventionally grown food; and 9 out of 10 believe organic fruits and vegetables are grown without 

pesticides of any kind (Avery, 2007). 

“Organic agriculture is a holistic production management system which promotes and enhances 

agro-ecosystem health, including biodiversity, biological cycles and soil biological activity. It 

emphasizes the use of management practices in reference to the use of off –farm inputs, taking 

into account that conditions required locally adopted systems. This is accomplished by using, 

where possible, agronomic, biological and mechanical methods as opposed to using synthetic 

materials to fulfill any specific function within the system” (FAO/WHO Codex Alimentarius 

Guidelines, 1999)” 

Components of Soil Fertility 

The use of the term ‘soil fertility’ is of little value unless the physical, chemical and 

biological properties of soil that contribute to its fertility are all considered (Abbott and Murphy, 

2003). 

Soil Physical Fertility 

Soil physical fertility contributes to the sustainability of organic farming systems by creating 

the framework in which biological and chemical processes supply nutrients to plants protect soil 

from erosion. Soil fertility in organically managed systems is generally improved compared to 

conventional practices (Glover et al., 2000, Shepherd et al., 2002) due to the beneficial effects of 

increased organic matter inputs on soil organisms and soil structure. Organic matter does little to 

improve soil aggregation, without the activity of soil organisms. Improved soil structure and root 

growth may be critical in organic farming systems for effectively using soil reserves of nutrients 

- 47 -


and poorly soluble fertilizers and for preventing nitrogen (N) leaching from mineralizing legume 

residues (Thorup-Kristensen, 2001). In some situation, soil physical characteristics are more 

dependent on soil type than on management (Drinkwater et al., 1995). 

Soil Chemical Fertility 

Chemical fertility of the soil depends to a large degree on low management practices 

facilitate beneficial biological processes. The chemical fertility of soil reflects its capacity to provide 

a suitable chemical and nutritional environment to plants (Stockdate et al., 2002) and to support 

biological and physical processes (Abbott and Murphy, 2003). Traditional methods for prediction 

fertilizer applications for building and maintaining soil chemical fertility may not be appropriate in 

organic farming systems (Oberson et al., 1993, Condron et al., 2000, Watson et al., 2002 a). 

Soil Biological Fertility 

Soil biological fertility refers to soil processes involving organisms that improve plant 

growth both directly (e.g. symbiosis with root nodule bacteria and mycorrhizal fungi) and indirectly, 

through their depicts on soil chemical fertility (e.g. organic matter mineralization and mineral 

dissolution) and physical fertility (e.g. soil aggregation) (lee and Pankhurst 1992, Degens 1997). 

Soil biological fertility can be quantified by measuring the size, activity, diversity and function of 

communities. A soil’s capacity to support biological fertility is determined by inherent physical and 

chemical characteristics as well as management practices. Organic farming may alter the function 

of the soil microbial community, increasing its ability to release nutrients form organic and poorly 

soluble sources, thereby compensation for the absence of soluble nutrient inputs (Oberson et al., 

1993; Penfold et al., 1995; AQIS, 1998; Ryan, 1999). Practices that enhance function of 

arbuscular mycorrhizal (AM) fungi and root nodule bacteria have potential to improve some 

aspects of soil biological and chemical fertility. 

The four principles of organic agriculture are as follows: 

Principle of health 

Organic Agriculture should sustain and enhance the health of soil, plant, animal, human 

and planet as on and indivisible. This principle points out that the health of individuals and 

communities cannot be separated from the health of ecosystem - healthy soils produce healthy 

crops that foster the health of animals and people. The role of organic agriculture, whether in 

farming, processing, distribution, or consumption, is to sustain and enhance the health of 

ecosystems and organisms from the smallest in the soil to human beings. In particular, organic 

agriculture is intended to produce high quality, nutritious food that contributes to preventive health 

care and well-being. In view of this it should avoid the use of fertilizers, pesticides, animal drugs 

and food additives that may have adverse health effects. 

Principle of ecology 

Organic Agriculture should be based on living ecological systems and cycles, work with 

them, emulate them and help sustain them. This principle roots organic agriculture within living 

ecological systems. It states that production is to be based on ecological processes, and recycling. 

- 48 -


Nourishment and will-being are achieved through the ecology of the specific production 

environment. For example, in the case of crops this is the living soil; for animals it is the farm 

ecosystem; for fish and marine organisms, the aquatic environment. 

Principle of fairness 

Organic Agriculture should build on relationships that ensure fairness with regard to the 

common environment and life opportunities. Fairness is characterized by equity, respect, justice 

and stewardship of the shared world, both among people and in their relations to other living 

beings. This principle emphasizes that those involved in organic agriculture should conduct human 

relationships in a manner that ensures fairness at all levels and to all parties- farmers, workers, 

processors, distributors, traders and consumers. 

Principle of care 

Organic Agriculture should be managed in a precautionary and responsible manner to 

protect the health and well being of current and future generations and the environment. Organic 

agriculture is a living and dynamic system that responds to internal and external demands and 

conditions. Practitioners of organic agriculture can enhance efficiency and increase productivity, 

but this should not be at the risk of jeopardizing health and well-being. 

World of Organic Agriculture 

According to the latest FiBL-IFOAM survey on certified organic agriculture worldwide (as 

on end of 2010) data on organic agriculture are available from 160 countries. There are 37 

million hectares of organic agricultural land (including in-conversion areas). The regions with the 

largest areas of organic agricultural land are Oceania (12.1 million hectares), Europe (10 million 

hectares), and Latin America (8.4 million hectares). The countries with the most organic 

agricultural land are Australia, Argentina, and the United States. Currently 0.9 percent of the 

agricultural land is organic. By region, the highest shares are in Oceania (2.9 percent) and in 

Europe (2.1 percent). In the European Union, 5.1 percent of the farmland is organic. 

Global sales of organic food & drink reached 59 billion US dollars in 2010 according to 

Organic Monitor. The market has expanded over three-fold in ten years (2000:17.9 billion US 

dollars). Although growth has slowed since the financial crisis started in 2008 sales have 

continued to increase at a healthy pace. Demand for organic products is concentrated in two 

regions; North America and Europe comprise 96 percent of global revenues. The high degree of 

sales concentration highlights the disparity between production and consumption indeed most 

organic food production in regions such as Africa and Latin America is export-geared. In 2010, the 

countries with the largest markets were the United States, Germany, and France, and the highest 

per capita consumption was in Switzerland, Denmark, and Luxemburg. 

Indian Scenario in brief 

Growth in area 

Emerging from 42,000 ha under certified organic farming during 2003-04, the organic 

agriculture grew 29 fold during the period up to 2008-09. By March 2011 India had brought more 

than 4.43 million ha area under organic certification process. Out of this cultivated area accounts 

for 0.77 million ha while remaining 3.65 million ha was wild forest harvest collection area (Table 1). 

- 49 -


Export of organic commodities- in spite of dwindling area and threat of BT cotton to organic 

cotton the export of organic commodities continued to grow in double digit. The growth in export, in 

terms of total quantity, in terms of total value in INR and in terms of total value in US$ was 22, 33 

and 41% respectively. 

Table – 1 Growth of area under organic management 

S. Years Area in ha under organic certification process 

No. 

Cultivated (organic + in-conversion) Wild harvest 

1 2003-04 42,000 NA 

2 2004-05 76,000 NA 

3 2005-06 1,73,000 NA 

4 2006-07 5,38,000 24,32,500 

5 2007-08 8,65,000 24,32,500 

6 2008-09 12,07,000 30,55,000 

7 2009-10 10,85,648 33,96,000 

8 2010-11 7,77,517 36,50,000 

Organic farming systems are guided by an overriding philosophy of “feed the soil to feed 

the plant.” This basic precept is implemented through a series of approved practices designed to 

increase soil organic matter, biological activity, and nutrient availability. Over time, adding organic 

materials such as green manure, crop residues, and composts to cultivated soils builds levels of 

soil organic matter. As soil organic matter increases, the ability of the soil to supply nutrients to 

crops also increases. The ultimate goal is a healthy, fertile, biologically active soil with improved 

structure and enhanced nutrient availability. Many soil amendments and organic fertilizers 

commonly approved for organic production systems have appreciable amounts of nutrients, but 

only a portion of these nutrients are available to the current crop. 

Role of organic matter and humus 

The increase of soil organic matter to optimum levels is a key aspect of any organic 

production system. Native organic matter levels are relatively low in Indian soils, generally ranging 

from less than 1 percent to 2 percent. Studies have shown that it is unreasonable for a grower to 

expect to increase soil organic matter by more than about 1 percent, but a relatively small increase 

can dramatically improve the soil fertility environment in a given field. Soil organic matter improves 

cation exchange capacity and serves as a reservoir of nutrients for the growing crop. Incorporation 

of organic matter, also improves soil aeration, drainage, and water-holding capacity. Green 

manure crops are an economical means for elevating soil organic matter temporarily and providing 

nitrogen for the succeeding crop. They also reduce soil erosion and may offer benefits related to 

pest and disease suppression. When green manure is not practical, composts and other approved 

amendments are useful. Compost is a relatively economical organic source of nutrients, but 

different composts can be quite variable depending upon the source. Growers need to understand 

the factors that contribute to compost quality. Incorporation of crop residues, if not used as cattle 

feed or for composting, can also add organic matter to the soil and help recycling the nutrients 

- 50 -


particularly potassium. 

The decomposition of organic matter in soils can provide much of the nitrogen (N), 

phosphorus (P), and sulfur (S) needed for crop nutrition. A portion of the N from many organic 

amendments is converted readily into available mineral forms. Phosphorus from organic 

amendments reacts quickly, is bound to soil minerals, and moves very little from where it is placed. 

Potassium (K), calcium (Ca), and magnesium (Mg) are relatively soluble from plant residues or soil 

organic matter fractions and also contribute to the soil pool of these nutrients. Organic matter is 

also a valuable balanced source of many minor elements. Organic matter releases nutrients as it 

decomposes and provides slow, constant availability. Soil organic matter contains a number of 

fractions that vary in composition and activity. Humus is the most resistant and mature fraction of 

soil organic matter. It is very slow to decompose and may last for hundreds of years. Residues that 

are slow to decompose (such as hay or corn stalks) are more efficient producers of humus than 

are more readily decomposed materials. However, relatively little is understood about the benefits 

of humus or other specific organic matter fractions for crop growth, and an organic grower’s crop 

management efforts should be directed toward increasing total soil organic matter. 

Nutrient sources 

Green manure-Growing a green manure crop that includes a N-fixing legume is the most 

economical way to provide N to a succeeding crop. The amount of N contributed depends upon 

the species and vigor of the green manure, and ultimately on the duration of its growth cycle. 

Typically, a green manure crop will require approximately 50 to 60 days of growth to fix between 

60 and 90 kg N per ha. Recent research suggests that the available N from a green manure 

increases over a four- to six-week period following incorporation, and then returns to preincorporation 

levels. Therefore, crops following a green manure rotation may require additional 

applications of N later in the season. The green manure crops may also harvest N, P and K from 

deep in the soil profile and make them more available to the succeeding crop. 

Compost-Compost is a relatively cost-effective commercial organic source of N. Compost 

also provides P, K, Ca, Mg, S, and other minor nutrients in fairly well-balanced amounts. Although 

actual concentrations of P and K in compost are low, the total additions may be quite high due to 

the high volume of material applied. When applying compost, the challenges are to know and 

understand its composition and to determine how to use it most efficiently. The grower should 

understand the composting process used by the supplier and know the sources of raw material 

used. If the materials that are being composted are low in nutrients, the compost will have a low 

nutrient analysis. Poor-quality or immature compost may actually tie up nitrogen in the soil and 

decrease the availability of N to the growing crop. The carbon-to-nitrogen ratio (C: N) of a compost 

is one indication of the maturity and N availability. As the C: N ratio rises above 20:1, the tendency 

for N from the soil to be tied up increases. A compost with a C: N ratio of less than 20:1 will 

generally release N to the succeeding crop. 

- 51 -


Three types of composts are available to organic farmer’s viz. normal compost (NADEP), 

vermi-compost and biodynamic compost. The composition of these composts varies and should 

be considered before deciding the rate of application. Use of suitable microbial cultures may 

accelerate the process of composting and addition of Azotobacter can increase N content of the 

compost. Similarly, addition of natural P sources such as rock phosphate can enrich the compost. 

Animal Manure- Decomposed animal manure (FYM) can also be a balanced source of N 

and other major and minor nutrients. Fresh manure may be of limited use because of relatively 

high transport costs, the potential for pollution problems, and the potential for crop injury. Another 

potential limitation with manure is the availability of a consistent supply of a material that is uniform 

enough to be confidently incorporated into a production programme. Organic certifying agencies 

may limit the type or timing of applications of manure on organic production fields. A public 

perception of increased food-safety–related problems relating to manure fertilization might further 

limit the use of manure. 

Other commercial organic fertilizers- A number of approved organic fertilizers or natural 

materials are available commercially (Table 1). Many of these materials are by-products of fish, 

meat, and soybean processing industries. The commercial formulations and nutrient analyses of 

these materials vary considerably. In general, they range from 1 to 12 percent N and provide P, K, 

or both along with N. Other simple fertilizer materials that offer only one macronutrient include: 

o 

o 

o 

o 

blood meal (N) 

rock phosphate (P) 

potassium sulfate (mined) (K) 

green sand (K) 

Certain by-products of the meat processing industry, such as blood and bone meal, have 

recently come under scrutiny because of food safety concerns and the potential for disease 

transmission. 

Table 1: Common organic fertilizer materials and their approximate analysis (%, dry 

weight basis) 

_______________________________________________________________________ 

Nitrogen (N) Phosphorus (P 2 O 5 ) Potassium (K) 

_______________________________________________________________________ 

Fish meal or powder 10–11 6 2 

Poultry manure 2–3 1.5 1.5 

Seabird and bat guano 9–12 3–8 1–2 

Alfalfa meal 4 1 1 

Cottonseed meal 6 0.4 1.5 

Soybean meal 7 2 1 

Bone meal 2 5 0 

Kelp


circumstances for correction of minor element deficiencies such as zinc or copper deficiency. 

Application of approved source materials will raise soil levels to a range where they are not 

deficient. 

Special-purpose fertilizers-Specific approved nutrient sources of K, Ca, and Mg may be 

useful to an organic grower when a deficiency or imbalance is indicated by a soil test. Materials 

such as gypsum, lime, and potassium-magnesium sulfate have been in use in agriculture for many 

years and their value is thoroughly tested. These materials may be used to correct deficiencies or 

imbalances of potassium, calcium, or magnesium, and lime may be used to raise soil pH. Gypsum 

also is often applied to replace exchangeable sodium prior to leaching a high-sodium soil (usar 

land) or to improve water infiltration on clay soils with poor structure. Pyrites may also be used as 

amendment for sodic soils. Materials derived from kelp and other processed seaweed contains 

nutrients and often plant hormones and growth regulators. Some claim that microbial soil 

stimulants enhance growth or reduce soil pests. 

Biofertilizers- Three types of biofertilizers are used viz. i) Symbiotic N 2 fixers such as 

Rhizobium culture for legumes, ii) free living N 2 fixers (non-symbiotic bacteria) such as 

Azotobacter and Azospirillum sp. for cereals, blue green algae and Azolla for rice and iii) P 

solubilizers such as Pseudomonas sp. While symbiotic N2 fixers inoculated in legumes can fix 

substantial amount of atmospheric N2 to feed the host plant, free-living N2 fixers contribute much 

less, usually 10-30 kg/ha. P solubilizers enhance the availability of native inorganic P. Biofertilizers 

are live materials, hence should be handled carefully and favorable environment in the field should 

be assured for desired results. 

Managing soil fertility in organic farming systems 

The practices used to manage soil fertility in organic farming systems should be 

understood in terms of the aims and underlying principles on which they are based. Therefore, 

practices that facilitate the efficient re-use of nutrients and organic matter within the farm are 

stressed. Also, organic production standards only permit non-synthetic fertilizers that are poorly 

soluble in the soil solution. Nutrients management in organic farming systems is not simply 

replacement of soluble fertilizers with insoluble fertilizers. To build and maintain adequate soil 

fertility, organic farming systems must integrate management practices such as those discussed 

below. Mixed livestock – arable systems, crop rotations, legumes, organic matter inputs and the 

use of fertilizers that are not readily soluble in soil; similar practices also characterize conventional 

farming systems that address sustainability issues, including the use of legumes to manage plant 

and animal nutrition in broad acre livestock-crop production and crop and forage rotations to 

manage pests and soil fertility. 

Livestock 

Livestock can directly improve soil chemical and biological fertility by introducing organic 

matter and nutrients in manure and manuring. Rotation that includes livestock can be a key 

- 53 -


component of sustainable farming systems. The retention of mixed farming in organic farming 

systems and the associated increases in spatial and temporal habitat heterogeneity was partly 

responsible for increased diversity of organisms observed on organic farms, from soil microbes to 

mammals and birds. 

Crop rotation 

Rotations facilitate processes that alleviated some of the fertility constraints ot production 

that are addressed in conventional farming system by use of synthetic inputs. Organic rotation 

may include greater use of greater use of green manures and cover crops, emphasize different 

regional crops, and have longer pasture phases than on conventional farms, leading to higher 

plant diversity in space and time. Rotations are also used to manage soil physical fertility by 

emphasizing inputs of organic matter from pasture phase, green manures of cover crops. 

Legumes in rotations 

Legumes are a fundamental component of organic farming system (in pastures, green 

manures, cover crops or food crops) because they reduce or eliminate the need for external N 

fertilizers providing they are effectively nodulated. The sustainability of legume use to supply crops 

with N in either organic of conventional farming systems depends on the: 

1- Fixation of sufficient N in the legume biomass: 

2- Ability of the soil community to increase mineralization of organic N; and 

3- Capacity of farming practices to maximize the beneficial soil fertility and environmental 

effects of legumes and minimize their negative effects. 

The sustainability of using legumes to supply crop requirements for N also depends on the 

capacity of organic management practices to maximize beneficial effects of legumes while 

minimizing the potential for N leaching. Intercropping with legumes can increase the efficiency with 

which soil nutrients are used. Steen Jensen and Hauggaard-Nielsen (2003) advocated increased 

use of legumes in farming systems because of beneficial environmental effects including improved 

soil structure, erosion protection, increased biological diversity, stimulation of rhizosphere 

organisms, acidification of alkaline soil and reduced energy use and carbon dioxide (CO2) 

production on and off the farm. 

Fertilizers 

The fertilizers permitted in certified organic farming systems, and in some cases the 

amount that may be applied, are restricted by organic certification standards. They are loosely 

divided into two categories: (i) naturally occurring geological resources (minerals) and (ii) organic 

materials. Minerals permitted as fertilizers in organic farming systems include lime, gypsum, rock 

phosphate, guano, elemental sulfur (S), dolomite and various ground silicate minerals. Organic 

materials include those produced on farms such as green manure, animals manure and compost 

as well as off-farm sources such as fish, blood and bone meal, seaweed extracts and microbial 

products. Complete lists of fertilizers permitted in organic farming systems can be found in the 

- 54 -


various organic certification standards. 

Conclusion 

Organic farming intensifies farm-internal processes like biological activities of soils, 

recycling of livestock and crop waste, enhanced biodiversity as well as nitrogen fixation and 

improved phosphorous availability by symbiosis. Organic farming builds up soil fertility and 

increases or conserves soil organic matter. Thus, supply and demand of nutrients get 

synchronized, water and soils get conserved and CO2 sequestered into the soil. 

REFERENCES 

• Abbott, L.K. and Murphy, D.V. 2003. What is biological fertility? In: Abbott L.K. and Murphy, D.V. 

(eds) soil Biological Fertility- A Key to Sustainable Land Use in Agriculture. Kluwer 

Academic Publishers, the Netherlands. pp. 1-15. 

• AQIS 1998. National Standards for Organic and Bio-dynamic Produce. Australian Quarantine and 

Inspection Service (AQIS), Canberra. 

• Avery, A. 2007. Going organic. Crops & Soils. Vol. 40(1):8-12. Amer. Soc. Agron. Madison, WI. 

USA. 

• Avery, A. 2007. Going organic. Crops & Soils. Vol. 40(1):8-12. Amer. Soc. Agron. Madison, WI. USA. 

• Biao, X, X. Wang, Z. Ding, and Y. Yang. 2003. Critical impact assessment of organic agriculture. 

J. Agric. Environ. Ethics. 16:297-311 

• Drinkwater, L.E.,Letourneau,D.K., Workneh, F., van Bruggen, A.H.C. and Shennan, C. 1995. 

Fundamental differences between conventional and organic tomato agroecosystems 

in California. Ecological Application 5:1098-1112. 

• FAO 1999. Organic Agriculture. Food and agriculture Organization o the United Nations, Rome. 

http://www.fao.org/unfao/bodies/COAG/COAG15/X0075E.htm. Accessed 26/2/99. 

• Galantini, J., R. Rosell, 2006. Long-term fertilization effects on soil organic matter quality and 

dynamics under different production systems in semiarid Pampean soils. Soil & tillage 

research, 87: 72-79. 

• Glover, J.D., Reganold, J.P. and Andrews, P.K. 2000. Systematic method for rating soil quality of 

conventional, organic and integ4rted apple orchards in Washington State. Agriculture, 

Ecosystem and Environment 80:29-45. 

• Gosling, P., M. Shepherd. 2005. Long-term changes in soil fertility in organic arable farming 

systems in England, with particular reference to phosphorus and potassium. Short 

communication. Agriculture, ecosystems and environment, 105: 425-432. 

• Lee, K. E. and Pankhurst, C. E. 1992. Soil organisms and sustainable productivity. Australian 

Journal of Soil Research 30:855-892. 

• Lotter, D.W. 2003. Organic agriculture. Journal of Sustainable Agriculture, 21: 59–128. 

• Oberson, A., Fardeau, J.C., Besson, J. M. and Sticher, H. 1993. Soil phosphorus dynamics in 

cropping systems managed according to conventional and biological agricultural 

methods. Biology and fertility of Soils 16:111-117. 

• Olesen, J.E., Schelde, K., Weiske, A., Weisbjerg, M.R., Asman, W.A.H., Djurhuus, J., (2006): 

Modelling greenhouse gas emissions from European conventional and organic dairy 

farms. Agriculture, Ecosystems and Environment 112, pp.207-22. 

• Penfold, C.M., Miyan, M.S., Reeves, T. G. and Grierson, I. T. 1995. biological farming for 

sustainable agricultural production. Australian Journal o f Experimental Agriculture 

35:849-856. 

• Ryan, M. 1999. Is and enhanced soil biological community, relative to conventional neighbours, a 

consistent feature of alternative (organic and biodynamic) agricultural systems? 

Biological Agriculture and Horticulture 17:131-144. 

- 55 -


• Shepherd, M.A., Harrison, R. and Webb, J. 2002. Managing soil organic matter- implication for soil 

structure on oranic farms. Soil Use and Management 18:284-292. 

• Smith, K.A., Conen, and F. (2004): Impacts of land management on fluxes of trace greenhouse 

gases. Soil Use and Management 20, 255-263. 

• Stockdale, E.A. and Cookson, W.R.2003. Sustainable farming systems and their impact on soil 

biological fertility-some case studies. In: Abbott L.K. and Murphy, D.V. (eds) Soil 

Biological Fertility- A Key to Sustainable Land Use in Agriculture. Kluwer Academic 

Publishers, The Netherlands. pp 225-239. 

• Stockdale, E.A., N.H. Lampkin, M. Hovi, R. Keatinge, E.K.M. Lennartsson, D.W. Macdonald, S. 

Padel, F.H. Tattersall, M.S. Wolfe, C.A. Watson. 2001. Agronomic and environmental 

implications of organic farming systems. Adv. Agron., 70: 261–325. 

• Thorup- Kristensen, K. 2001. Are differences in root growth of nitrogen catch crops important for 

their ability to reduce soil nitrate-N content, and how can this be measured? Plant and 

Soil 230:185-195. 

• Yussefi, M., H. Willer. 2007. Organic farming worldwide 2007: Overview & main statistics. In: The 

world of organic agriculture. Statistics and emerging trends. 

- 56 -


The Role of Soil Microfauna in Maintaining Soil Health 

Navneet Pareek 

Department of Soil Science, G.B.P.U.A.&T., Pantnagar- 263 145 (Uttarakhand) 

Soil organisms (biota) carry out a wide range of processes that are important for soil health 

and fertility in both natural and managed agricultural soils. The total number of organisms, the 

diversity of species and the activity of the soil biota will fluctuate as the soil environment changes. 

These changes may be caused by natural or imposed systems. The microfauna are a diverse 

group which includes the protozoa, nematodes, and some arthropods, primarily mites and 

springtails (collembola). Microfauna are usually defined as being smaller than 0.2 mm, although 

some soil nematodes can reach lengths of 5.0 mm. 

Protozoa are single-celled animals that feed primarily on bacteria, but also eat other 

protozoa, soluble organic matter, and sometimes fungi. They are several times larger than 

bacteria, ranging from 1/5000 to 1/50 of an inch (5 to 500 μm) in diameter. Both protozoa and 

nematodes are aquatic and live and move in soil water films and water-filled pores of soil 

aggregates. Protozoa are classified into three groups based on their shape. Species of 

Mastigophora or flagellates are the smallest (5 to 20 μm) and use one to four whip-like flagella to 

move. Flagellates feed primarily on bacteria and are the most numerous of soil protozoa. 

Ciliophora or ciliates are the largest (10 to 80 μm) protozoa and the least numerous and move by 

means of hair-like cilia. The cilia use vibrating hairs to move. Ciliates use the fine cilia along their 

bodies like oars to move rapidly through the soil. They eat the other two types of protozoa, as well 

as bacteria. Cilates may consume as many as ten thousand bacteria per day. Sarcodina or 

amoebae also can be quite large and move by means of a temporary foot or “pseudopod.” 

Amoebas reside in the rhizosphere and at the root surface where they graze on bacteria 

populations. There are two types of amoebas: testate and naked. Testate amoebas are encased in 

a rigid chitin shell or testa, while naked amoebas lack a rigid shell. Naked amoebas can change 

shape and explore tiny pore spaces making them valuable for soil nutrient recycling. 

Nematodes or roundworms are non-segmented worms with tapered ends typically 1/500 of 

an inch (50 μm) in diameter and 1/20 of an inch (1 mm) in length. They have a head, and a tail 

with a well developed central nervous and fertility system with a complete digestive system, so 

they are considered the most primitive animal. They are small enough to fit in most soil pores and 

soil aggregates. They are classified in the animal phylum Nemata and are best known for causing 

infectious disease in plants and animals, but they also play an important role in soil and crop 

ecology. Nematodes are aquatic organisms so they require adequate soil moisture to move in the 

soil. Nematodes can be divided into five broad groups based on their diet with the first four groups 

being free living. Bacterial-feeders consume bacteria through a stoma, a large open channel. 

Fungal-feeders feed by puncturing the cell wall of fungi using a small slender stylet to suck out the 

internal contents. Predatory nematodes eat all types of nematodes and protozoa using a stylet. 

- 57 -


They eat smaller microorganisms whole or attach themselves to the cuticle of larger nematodes, 

scraping away until the prey’s internal body parts can be extracted. Omnivores eat a variety of 

organisms including bacteria, fungus, protozoa, other nematodes and roots and may have a 

different diet at each life stage. Root-feeders are plant parasites feeding on roots, and thus are not 

free-living in the soil because they live either inside or outside the plant root, depending on the 

plant root for a food source. 

The role soil microfauna play in the cycling of nutrients in ecosystems has been recognized 

for many years (Verhoef and Brussaard, 1990). They have significant impact on plant diseases, 

and soil health. Soil microfauna play a major role in the decomposition and turnover of organic 

matter, regulation of population densities of microflora and other biochemical processes. Protozoa 

are unicellular organisms and are the main consumers of microbial biomass. Nematodes are the 

most numerous multicellular animals on earth, exploiting virtually all of the planet's terrestrial, 

aquatic and marine habitats (except open water). Many nematodes are parasites of insects, plants 

or animals; others feed on fungi, bacteria and other nematodes. Between 500,000 and 

100,000,000 nematode species are believed to live on this planet, but less than 25,000 described 

species are yet classified in the phylum Nemata. Microorganisms are ubiquitous inhabitants of all 

soils. A handful of soil will contain thousands of microfaunal organisms. 

Microfaunal species feeding on other microorganisms help, by their grazing pressure, keep 

the microorganism populations young and active, thus stimulating microbial soil processes. 

Absence of microfauna can result in incomplete cycling of elements. 

The concept of suppressive soils was described by Baker and Cook (1974) in their first 

book on the biological control of plant pathogens. The suppressiveness is the ability of a soil to 

prevent, truncate or delay the development of a disease even though favorable environmental 

conditions exist. The actual mechanisms of disease suppression involve the influences of various 

microbial antagonists, soil fungistasis (inhibition of fungal growth), and physical and chemical 

properties of soils. The role of soil fauna in this process has recently been reported. 

Organic Matter Decomposition 

As nematodes and protozoans feed upon microbial populations, they consequently will 

affect organic matter decomposition. It is likely that such feeding ultimately liberates nutrients 

immobilized in microbial cells or reduces competition between microorganisms so that 

mineralization is actually accelerated. "These activities not only influence the general nutrition, 

health, and vigour of higher plants (which relates to disease susceptibility), but also determine the 

competitive behavior of root-infecting fungi and their microbial antagonists." These indirect and 

direct impacts are important ones for further study. 

The role of microarthropods in mineralization is also recognized. Mites and collembola are 

known to fragment organic matter as they feed on soil microflora. This fragmentation to finer 

particles creates new surface areas for microbial colonization and consequently speeds the 

- 58 -


decomposition and mineralization processes. 

There are several other interesting features of the microbiotic community, including 

increased nitrogen fixation by nitrogen-fixing bacteria (Azotobacter spp.) where protozoa are 

present, and the behavior of bacterial and fungal-feeding nematodes. 

Rhizosphere Effects 

The rhizosphere is the soil zone surrounding and influenced by plant roots. The primary 

influences in this zone are root exudates and the chemical and physical features of the root-soil 

interface. Root exudates and sloughed root cells in the rhizosphere provide a rich carbon source 

for microbes. As the microbial population increases, so does the activity of microbe-grazing fauna, 

leading eventually to the release of inorganic nitrogen and phosphorus. 

Root exudates can also have a strong influence on soil pathogens. "The nutrients in 

exudates release dormant spores and sclerotia from the grip of soil fungistasis, a natural 

phenomenon imposed by chemical inhibitors and microbial competition for nutrients. Propagules 

freed from fungistasis germinate and establish infection if they are not first consumed by 

mycophagous [fungus-eating] animals. Root exudates are also important in the activation of 

quiescent nematode stages and in the movement of plant parasitic forms to infection sites." 

Specific Soil Fauna-Plant Disease Relationships 

The fauna have in the rhizosphere are sufficient to indicate that soil fauna do regulate 

pathogen populations to some degree. Some interesting relationships are summarized in table 1. 

Table 1. Summary of biological control activities of soil micro-and meso- fauna. 

Biocontrol Agent 

Amoebae 

(At least 5 different species) 

Nematodes 

(Numerous species from 7 genera) 

Microarthropods 

Mites 

Collembola 

Action 

Conidiall perforations and/or hyphal feeding on 

numerous species of fungi including Cochliobolus 

sativus, Thielaviopsis basicola, Fusarium oxysporum 

F. sp. melonis, F. roseum, F. solani, Verticillium 

dahliae, Gaeumannomyces graminis, and 

Phytophthora cinnamomi. 

Also may feed on bacteria, flagellates, blue green 

algae, diatoms, and nematodes. 

Feed on various species of Rhizoctonia, Aternaria, 

Pyrenochaeta, Botrytis, Fusarium, and Agaricus. 

Fungal feeders, but probably play a minor role in 

disease suppression. 

Two species found to feed extensively on several 

plant pathogenic fungi including Rhizoctonia solani, 

and Fusarium oxysporum. Show marked preference 

for particular types of fungi. 

- 59 -


Soil microfauna as bioindicators of soil health 

In view of their important role in various soil processes, soil microfauna have been 

suggested as bioindicators of soil health (Gupta and Yeates, 1997). The composition of nematode 

communities (plant-parasitic and free-living) may be used as bioindicators of soil health or 

condition because composition correlates well with nitrogen cycling and decomposition, two critical 

ecological processes in soil. Maturity and trophic diversity indices withstand statistical rigor better 

than do abundances, proportions, or ratios of trophic groups (Neher, 2001). Maturity indices 

respond to a variety of land-management practices, based largely on inferred life history 

characteristics of families. Similarity indices may be more useful than diversity indices because 

they reflect taxon composition. Improving existing indices or developing alternative indices refined 

by a greater understanding of the biology of key taxa may enhance the utility of nematodes as 

bioindicators. 

Conclusions 

Protozoa consume primarily bacteria and other protozoa and help to regulate bacteria 

densities, composition, and populations. In this manner soil microfauna play an important role in 

suppression of plant pathogens and represent a significant biological control potential. However, 

there has not been adequate field testing to verify if this biocontrol potential can be exploited in 

cropping systems. In addition, any evaluation of a candidate organism must include the possibility 

of adverse effects upon plants, animals, or the environment. 

Microfauna also help in maintaining soil health they consume other microbes in the soil and 

release the N as ammonia, which becomes available to plants. Protozoa and bacteria tend to be 

more numerous than nematodes in cultivated or tilled soils. Nematodes feed on bacteria, fungus, 

protozoa, and other nematodes, but some are root feeders. A problem with the fungal-feeding 

amoebae, for example, maybe their effect on other beneficial organisms such as the mycorrhizal 

fungi. Therefore, efforts to manipulate and exploit the friendly fauna populations for crop benefit 

must be compatible with microbial symbionts, and other plant-growth promoting rhizosphere 

organisms, and with fungi and bacteria that are being promoted for biological control of diseases. 

This is clearly an area with great opportunities for further research. 

REFERENCES 

• Baker. E. F and R.J. Cook, 1974. Biological control of plant pathogens. W.H. Freeman & Co. 

Sanfransisco, 433pp. 

• Gupta, V.V.S.R; Yeates, G.W. 1997. Soil Microfauna as Bioindicators of Soil Health. In C.E. 

Pankhurst, B.M. Doube, V.V.S.R. Gupta, eds. Biological Indicators of Soil Health. 

Oxon, United Kingdom, CAB International. 

• Neher, D.A. 2001. Role of nematodes in soil health and their use as indicators. Journal of 

Nematology, 33(4):161–168. 2001. 

• Verhoef, H.A. and Brussaard, L. (1990). Decomposition and nitrogen mineralization in natural and 

agro-ecosystems: The contribution of soil animals. Biogeochemistry 11: 175-211. 

- 60 -


Soil Degradation- A Threat to Sustainable Agriculture 

Ramesh Chandra 


Soil is one of the most precious natural resources, which provides a medium for plant 

growth to meet our food and fibre need. Soil filters water, decomposes waste, stores heat, and 

exchanges gases and thus have great bearing on environmental quality. Soil is a limited and non– 

renewable resource. Experience has shown that with continuous utilization even with best 

technologies and skills, soil has reached a stage of fatigue resulting in decline or stagnation in the 

productivity in almost all crop production systems. Degradation of agricultural land has become a 

great cause of concern during the 21 st century and will remain high in the next century because of 

its direct impact on agricultural sustainability and food security. Soil degradation is the temporary 

or permanent lowering of the productive capacity of soil caused by over-grazing, deforestation, 

inappropriate agricultural practices, over exploitation and other man induced activities. In India, an 

ever increasing population places enormous demands on soil resources, which has only 2.4 per 

cent of the world's geographical area but supports over 16 per cent of the world's population. It has 

0.5 per cent of the world's grazing area, but has over 18 per cent of world's cattle population. 

These pressures have drastically degraded and caused significant shrinkage in the soil resources 

due to urbanization and industrial needs. 

The soil resources of India are enormous as 9, out of 12 Soil Orders which describe the 

soils of the planet earth, occur in India. However, some of the soils have severe constraints 

towards meeting the challenges of the next centuries. Land degradation is causing a heavy toll of 

soil resources every year in India. The latest estimates by NBSS and LUP, Nagpur using Global 

Assessment of Soil Degradation (GLASOD) guidelines indicate 187.8 M ha of land degraded to 

various degrees through different degrading processes. Soil degradation problem is especially 

severe in arid, semiarid and hilly regions. Important constraints are low soil fertility and nutrient 

depletion, multinutrient deficiency, physical degradation and accelerated soil erosion. Apart from 

inherent constraints, there are severe human induced constraints particularly in intensively 

cropped areas. 

Mechanisms that initiate soil degradation include physical, chemical, and biological 

processes (Lal, 1994) (Fig. 1). Important among physical processes are a decline in soil structure 

leading to crusting, compaction, erosion, desertification, and water logging and environmental 

pollution. Chemical processes include acidification, leaching, salinization, nutrient imbalance and 

toxicity, decrease in cation retention capacity and fertility depletion. Soil biological degradation 

processes include reduction in total and biomass carbon, and decline in land biodiversity. Climate 

change influences chemical, physical and biological processes and thus contributes to soil 

degradation to a great extant. The degraded lands eventually jeopardize human well-being. Soil 

structure is the important property that affects all three degradative processes. 

- 61 -


Soil physical degradation 

About 95.65 M ha of the cultivated land in India suffer from soil physical degradation, out of 

which shallow soil cover 25.02 M ha, hardening soils 20.35 M ha, highly permeable soils 10.77 M 

ha, soils with high mechanical impedance at shallow depth 10.63 M ha, slowly permeable soils 

9.43 M ha and other physical constraints 9.45 M ha (Yadav, 1996). Physical degradation through 

water logging, soil compaction, crusting etc. is serious problem affecting crop productivity. Erosion 

by water is the most serious degradation problem of the Indian soils. The analysis of the existing 

soil loss data indicate that soil erosion takes place at an average rate of 16.35 tonnes ha -1 year -1 

totalling 5,334 m tones year -1 . Nearly 29% of the total eroded soil permanently lost to the sea, and 

nearly 10% deposited in reservoirs, resulting in the reduction of their storage capacity by 1 to 2% 

annually. The remaining 61% of the eroded soil transported from one place to other. (Singh, 2000). 

Problems of physical deterioration of soils generally related to reduction in soil organic matter 

content, making them more prone to crusting and increased runoff. Another most serious soil 

degradation problem is of excessive wetness due to water logging. The estimates show that the 

soil area prone to water-logging is 11.6 M ha. Wind erosion is a serious problem in the arid and 

semi-arid regions of Rajasthan, Haryana, Gujarat, Punjab and coastal areas. Removals of natural 

vegetative cover resulting from excessive grazing and expansion of agriculture to marginal areas 

are the major human-induced factors leading to accelerated wind erosion. Wind erosion is also 

prevalent in the coastal areas where sandy soils predominate, and in the cold desert regions of 

Leh. Wind erosion is moderate to severe in arid and semi-arid regions of the northwest, covering 

an area of 28,600 km 2 , of which 68 per cent is covered by sand dunes and sandy plains. However, 

active wind erosion is observed in the extreme western sectors of the country. 

Soil chemical degradation 

Chemical degradation of soils can occur through a number of processes viz. the loss of 

nutrients and/or organic matter and accumulation of salts and/or pollutants. Amongst the soil 

groups, Alfisols and Ultisols, are prone to chemical deterioration due to nutrient depletion. It is 

estimated that about 70% area in the country is deficient in soil organic carbon; having less than 

1% Organic C. Deficiency of phosphorus is widespread in Indian soils with 49.3, 48.8 and 1.9% of 

soils having low, medium and high P status, respectively. There is also growing intensity of other 

plant nutrients deficiency including micronutrients in intensively cultivated areas. Analysis of 2.52 

lakhs surface soil samples collected from different parts of the India under AICRP on Micro- and 

Secondary Nutrients and Pollutants in Soils and Plants revealed that 49% soils in the country are 

deficient in Zn, 41% in S, 32% in B, 12% in Fe, 4% in Mn and 3% in Cu for crop production point of 

view. These deficiencies have not only adversely affected the growth of agricultural production, 

deteriorated the physical, chemical and biological environment of soils, but also caused imbalance 

of these essential nutrients in humans and animals (Singh, 1998). 

The other most important chemical process of soil degradation is soil salinization and soil 

- 62 -


sodicity. It is estimated that a total of 10.1 M ha area is suffering from salinity and/or alkalinity 

problems. While saline soils have excess of neutral soluble salts, that is, chlorides and sulphates 

of sodium, calcium and magnesium, alkali soils contain appreciable quantities of salts, such as 

sodium bicarbonate and/or carbonate and high amount of exchangeable sodium in the clay 

fraction. The salt-affected soils are of widespread occurrence in the arid, semi-arid and sub-humid 

(dry) zones of the Indo-Gangetic plains and coastal regions. Alkali (sodic) soils dominate in areas 

having mean annual rainfall of more than 600 mm. 

Soil biological degradation 

Soil biological processes and soil biodiversity are central to the soil fertility and soil physical 

properties. Unscientific and indiscriminate use of farm inputs such as fertilizers, insecticides, 

fungicides, weedicides and growth promoters etc. as a result of green revolution technologies 

resulted in biological degradation of soils. Conventional tillage is known to significantly reduce the 

diversity of soil bacteria by reducing both substrate richness and evenness. Plant species 

influences microbial community composition of soil via rhizo-deposition of organic substrates, 

which serves the source of energy for the microorganisms. Studies based on 16S rRNA gene and 

phospholipid fatty acid analysis have revealed shifts in the total microbial community in response 

to the different soil and crop management practices, indicating that deliberate management of soils 

can have a considerable impact on microbial community structure and functions in soil. 

Applications of chemical fertilizers and agrochemicals lower the soil microbial diversity. Soil 

bacteria were observed more sensitive to chemical N fertilizer application during the plant growth 

cycle (Seneviratne, 2009). 

Amelioration of Degraded Soils 

A degraded soil can be improved and made suitable for profitable crop production using 

proper management technology and inputs. However, the time and cost involved in reclaiming a 

degraded soil are the serious limitations. Bad management can turn good soil into deserts and 

vice-versa. Followings are some important advisable measures for amelioration of degraded soils 

to put them under profitable crop production systems. 

Enhancing soil organic matter 

Organic matter influences almost all the components of soils linked with crop production. 

Organic matter incorporated in to the soil can affect its structure, as indicated by porosity, 

aggregation and bulk density, as well as causing an impact in terms of content and transmission of 

water, air and heat and of soil strength. Maintenance of soil organic matter (SOM) vis-a-vis carbon 

sequestration is therefore, essential not only for restoration of the productivity of soils, but also 

improvement in overall soil health. Several organic materials such as FYM, green manures, city 

refuse, composts, forest litter, sewage and sludge, domestic and industrial wastes are available for 

use in crop production. Although, increasing soil organic matter in tropical climate is not easy. 

However, continuous application of lignocellulotic crop residue helps in building SOM temporarily. 

- 63 -


Besides, crop production practices of conservation tillage may help in building the SOM by 

avoiding its losses from soil through oxidation. 

Integrated nutrient Management 

Integrated nutrient management (INM) is an approach of effective and efficient utilization of 

all available nutrient resources i.e. soil reserve, organics, biofertlizers and chemical fertilizers, 

which are locally available, economically viable, socially acceptable and eco-friendly for sustaining 

and increasing crop production. India will require about 300 m tonnes of food grains by 2025 to 

feed around 1.4 billion populations. This would necessitate the use of about 45 m tonnes of 

nutrients. This much need of plants nutrients can not be met out by the chemical fertilizers alone 

with current growth rate in fertilizer consumption. The organic resources available presently, could 

meet nearly one-third of total nutrients requirement to achieve the targeted level of food grain 

production. INM practice also prevents the depletion of SOM and improves soil physical, chemical 

and biological health. 

Water management 

Water is a prime natural resource and is considered as a precious national asset. Over 

exploitation of ground water in several parts of the country resulted in declined ground water levels 

in pockets in 370 districts; reduced supply of water and subsided land in some places and is 

threatening the agriculture sustainability and food security (Samara and Sharma, 2010). Improper 

use of water and its poor management creates problems of salinity, sodicity and waterlogging. The 

modern irrigation techniques such as drip irrigation, sprinkler irrigation can become remunerative, 

if used for high values crops with good agriculture practices and optimum inputs. 

Soil conservation measures 

Various mechanical, agronomic and agro-forestry measures can be adopted for controlling 

soil and water erosion. Under mechanical measures like contour and graded bunds, bench, half 

moon and conservation bench terraces etc. and in agronomic measures like cropping systems, 

cover crops, mulching, contour cultivation tillage etc. are some of the promising techniques for 

controlling the loss of the top soil. Agro-forestry is becoming popular and a useful way to arrest the 

soil erosion on slopy lands. Moisture conservation in arid regions and plantations of multipurpose 

trees and shrubs are helpful in controlling soil loss through wind erosion. 

Conservation tillage 

Conservation tillage in a broad sense is any tillage system that is less intensive than 

conventional tillage. In this tillage both land preparation and sowing operations is combined in one 

operation or tillage operations for land preparation are eliminated altogether. The most important 

component of conservation tillage is the retention of crop residues on soil surface. The success or 

failure of conservation tillage depends on the use of herbicides, crop residue management and 

efficiency of planting equipments to place seed in soil below the residues. Conservation tillage 

practices minimize the soil disturbance, conserve moisture, control soil erosion, and increase SOM 

- 64 -


by reducing its losses via oxidation and addition through crop residue retention. 

Amendments in saline and sodic soils 

In the saline and sodic soils, plant growth is restricted due to increased level of salts. To 

get good production, the process of accumulation of salts and build up of soil electrical conductivity 

have to be reversed. To achieve these objectives provision of adequate drainage, replacement of 

high concentration of Ca ++ , Mg ++ and Na + ions from the soil exchange complex and leaching out of 

the soluble salts have to ensure. Deep ploughing, sub-soiling, profile inversion and scraping are 

few other options for managing the salt affected soils. These are only temporary measures for 

improving the plant growth and generally suitable only for saline soils. Alkali/sodic soil require 

neutralization of alkalinity and replacement of Na + ions from the soil exchange complex by the 

more favourable salt of Ca ++ ions using chemical amendments. The type of chemical compounds 

and their quantities required for reclamation depend upon physico-chemical properties of the soil, 

desired rate of replacement of Na + ions and economic consideration. Gypsum is the most 

economical and commonly used chemical amendment. Besides pyrite, presumed, rice husk, 

elemental sulphur, some agro based industrial effluents may also be used judiciously for improving 

the physico-chemical and biological properties of salt affected soils depending on their availability 

and economics. 

Liming in acid soils 

Acid soils in India cover about 30 percent of the total area of the country. Low pH of acid 

soils is not only harmful to plants, but also causes imbalance of plant nutrients restricting their 

availability to plants. Acids soils are generality deficient in calcium and magnesium, low in 

phosphorus and usually have toxicity of iron and aluminum. Micronutrients content of acids soils 

differs with locations depending upon the process of their development and parent materials. Lime 

application to the crops is the most suitable and easy way to increase crop production in theses 

soils. Since the crops have greater degree of tolerance for soil acidity especially in the pH range of 

5-6, the response of lime application vary with crops. Crops such as cotton, arhar, lentil, peas, 

maize show considerable response to lime application in terms of increase in the productivity, 

whereas upland rice, millets and mustard crops give little or no response to lime application in acid 

soils. 

Issues and Challenges 

The perception that enough is already known about soils is incorrect. Despite, significant 

and inevitable role of soils in maintaining food security, required emphasis has not been given to 

soil management by now. There is need to understand the role of society in sustaining agriculture 

and conversely, the role of soil in sustaining the society. The policies and practices that have 

contributed to soil degradation and decline in productivity have to be reversed. Appropriate 

national policies should be formulated and implemented to ensure no or minimum land 

degradation. Availability of sufficient research and development funds to match their significance in 

- 65 -


terms of the cost to society, if soils become degraded, must be ensured. The requirement of water 

(quality and quantity) for crop production must be assessed on long-term basis. An understanding 

and utilization of indigenous knowledge on land degradation, cropping and farming systems, and 

soil and water management is necessary for obtaining profitable crop production to ensure food 

security in degraded soils. 

REFERENCES 

• Lal, R. 1994. Sustainable Land Use Systems and Soil Resilience, dans Greenland, D.J. et 

Szabolcs, I. (édit), Soil Resilience and Sustainable Land Use, pp. 41-67. CAB - 

International, Wallingford, RU. 

• Samra, J. S. and Sharma, K. D. 2010. Ground water management for national food security. One 

day 2 nd National Ground Water Congress, Organized by Central Ground Water 

Board on March 22, 2010, Ministry of Water Resources, GOI, New Delhi. 

• Seneviratne, G. 2009. Collapse of beneficial microbial communities and deterioration of soil 

health: a cause for reduced crop productivity. Current Science 96:633. 

• Singh, G. B. 2000. VISION 2020: Natural resource management research. Division of Natural 

resource management, ICAR, Krishi Bhawan, New Delhi. 

• Singh, M.V. 1998. 28 th Progress report of 1996-98 for the AICRP of Micro- and Secondary 

Nutrients and Pollutants in Soils and Plants. IISS, Bhopal. Pp. 1-137. 

• Yadav, J.S.P. 1996. Land degradation and its effect on soil productivity, sustainability and 

environment. Journal of Soil and Water Conservation 40: 660-674. 

- 66 -


Role of Plant Growth Promoting Rhizobacteria in Crop Improvement 

Anita Sharma, Shubhi Sharma and Geeta Negi 

Department of Microbiology, G.B.P.U.A.&T., Pantnagar- 263 145 (Uttarakhand) 

Rhizosphere is a narrow region of soil that is directly influenced by root secretions and 

associated soil microorganisms that feed on sloughed-off plant cells, rhizodepositions (amino 

acids, hormones, vitamins) and numerous proteins and sugars released by the roots. These 

rhizodepositions promote extensive growth of bacteria and fungi which make micro colonies on 

root surface and show beneficial effect on plants growth. Beneficial effects of Plant growthpromoting 

rhizobacteria (PGPR) on different crops have been reported by Kloepper and Schroth, 

(1978). Rhizospheric bacteria help tolerate abiotic stress (Yang,et al. (2009). plant growthpromoting 

bacteria directly facilitate the proliferation of plants by fixing atmospheric nitrogen; 

producing siderophores (iron sequester), synthesizing phytohormones, enzymes and solubilizing 

minerals such as phosphorus and Zn. Moreover, many plant growth promoting bacteria possess 

several other activities that enable them to facilitate plant growth and, of these, may utilize different 

ones at various times during the life cycle of plant. PGP activity has been reported in strains 

belonging to several genera such as Azoarcus, Azospirillum, Azotobacter, Arthrobacter, Bacillus, 

Clostridium, Enterobacter, Gluconacetobacter, Pseudomonas, and Serratia (Somers and 

Vanderleyden, 2004). 

Applications of PGPR for crop improvement 

Biological nitrogen fixation 

A number of bacterial species belonging to genera Azospirillum, Alcaligenes, Arthrobacter, 

Acinetobacter, Bacillus, Burkholderia, Enterobacter, Erwinia, Flavobacterium, Pseudomonas, 

Rhizobium and Serratia are associated with the plant rhizosphere and are able to exert a 

beneficial effect on plant growth. Biological nitrogen fixation contributes 180 X 106 metric tons/year 

globally, out of which symbiotic associations’ produces 80% and the rest comes from free-living or 

associative systems. The ability to reduce and derive such appreciable amounts of nitrogen from 

the atmospheric reservoir and enrich the soil is confined to bacteria and Archaea. 

HCN production 

Although cyanide acts as a general metabolic inhibitor, it is synthesized, excreted and 

metabolized by hundreds of organisms, including bacteria, algae, fungi, plants, and insects, as a 

mean to avoid predation or competition. The host plants are generally not negatively affected by 

inoculation with cyanide-producing bacterial strains and host-specific rhizobacteria can act as 

biological weed-control agents. A secondary metabolite produced commonly by rhizosphere 

pseudomonads is Hydrogen Cyanide (HCN), a gas known to negatively affect root metabolism and 

root growth and is a potential and environmentally compatible mechanism for biological control of 

weeds. The HCN production is found to be a common trait of Pseudomonas (88.89%) and Bacillus 

(50%) in the rhizospheric soil and plant root nodules and is a serious environmental pollutant and 

- 67 -


a biocontrol metabolite in Pseudomonas species. 

Biosurfactant 

Biosurfactants are structurally diverse group of surface active molecules synthesized by 

the microorganisms. They are amphipathic molecules with hydrophilic and hydrophobic moieties 

that partition preferentially at the interface between fluid phases. The biocontrol potential of 

biosurfactant has been recently discovered. Rhamnolipids (type of biosurfactant containing 

rhamnose sugar produced by Pseudomonas) are highly effective against Pythium 

aphanidermatum, Plasmapara lactucae and Phytophthora capsici. Biosurfactants with both 

hydrophilic and lipophilic structural moieties facilitate the uptake of hydrocarbons into the cells. 

Microbial compounds like lipopeptide, glycolipids, fatty acids and polymeric biosurfactants have 

been found to have surface activity and able to reduce surface tension and interfacial tension 

between water and hydrocarbon phases. Environmental stimuli i.e. carbon substrate, limitation by 

C, N or P, Fe limitation and growth phase condition may affect biosurfactant production. 

Role of PGPR in nitrate mobilization 

Plant growth-promoting bacteria and NO 3 availability both affect NO 3 uptake and root 

architecture in plants. The presence of external NO 3 induces the expression of NO 3 transporter 

genes and elicits lateral root elongation in the part of the root system exposed to the NO 3 supply. 

By contrast, an increase in NO 3 supply leads to a higher plant N status (low N demand), which 

represses NO 3 transporters and lateral root development. The effects of PGPB on NO 3 uptake and 

root development are similar to those of low NO 3 availability (concomitant stimulation of NO 3 

uptake rate and lateral root development). 

Phosphate solubilizing microorganisms (PSM) 

Phosphorus is one of the - major plant nutrients required for proper plant growth but 90% 

Indian soils have inadequate supply of available phosphorus. Most of the essential plant nutrients 

including phosphorus remain in insoluble form in soil. Plants absorb P from the soil in the ionic 

form (H 2 PO -) 4 and (HPO 4 ) - 2. Low levels of soluble phosphate can limit the growth of plants. The 

phenomena of fixation and precipitation of P in soils depends upon pH. It has been established 

that there are specific groups of soil microorganisms which increase the availability of phosphates 

to plants, not only by mineralizing organic phosphorous compounds but also by rendering 

inorganic phosphorous compounds more available to them. Most efficient P solubilizers belong to 

genera Bacillus and Pseudomonas. Such bacteria and fungi can grow in media where Ca 3 (PO 4 ) 2 , 

FePO 4 , AlPO 4 , Apatite, Bone meal, Rock phosphate are the sole source of phosphate. The 

potential of phosphate solubilizing microorganisms has been assessed in Bacillus polymyxa, P 

striata, mycorrhizal fungi and B. firmis. These organisms are used as bioinoculants to enhance the 

availability of unavailable P to the plants. 

Zn solubilizing bacteria: Extensive use of chemical fertilizers in agriculture has exploited 

agricultural land drastically and has led to an increased soil pH which has ultimately disturbed the 

- 68 -


availability of essential micronutrients to the plants. Zn, a common and essential micronutrient of 

various crops becomes unavailable particularly at higher pH. Availability of Zn depends upon soil 

type, moisture, minerals, organic matter and soil biota. More than 90% of Zn remains unavailable 

to the plants. Rice, sorghum and maize are classified as most sensitive crops and show deficiency 

symptoms of Zn where as barley and wheat are less sensitive. It acts as an essential component 

of different enzymes. Zn is also required as a precursor of IAA for tryptophan synthesis. 

Pseudomonas and Bacillus are reported to solubilize Zn compounds (Saravanan, et al. 2003). 

Different authors have observed the role of organic acids (gluconic acid), root exudates, 

siderophores , cations and H + ions released by the plants/ bacteria in solubilization of insoluble Zn 

compounds (Simine et al.1998;Saravanan et al. 2007). 

Production of plant growth regulators 

Plant hormones are chemical messengers that affect a plant's ability to respond to its 

environment. Hormones are organic compounds that are effective at very low concentration; they 

are usually synthesized in one part of the plant and are transported to another location. They 

interact with specific target tissues to cause physiological responses, such as growth or fruit 

ripening. Each response is often the result of two or more hormones acting together. Because 

hormones stimulate or inhibit plant growth, many botanists also refer to them as plant growth 

regulators. Botanists recognize five major groups of hormones: auxins, gibberellins, ethylene, 

cytokinins, and abscisic acid. IAA (indole-3-acetic acid) is the member of the group of 

phytohormones and is generally considered the most important native Auxin. It functions as an 

important signal molecule in the regulation of plant development including organogenesis, tropic 

responses, cellular responses such as cell expansion, division, and differentiation, and gene 

regulation. Diverse bacterial species possess the ability to produce the auxin phytohormone IAA. 

The potential for auxin biosynthesis by rhizobacteria can be used as a tool for the screening of 

effective PGPR strains. The highest concentration of IAA is produced by bacterial strain P. 

fluorescens and Kocuria varians. 

Siderophore production 

Iron is an essential growth element for all living organisms. The scarcity of bioavailable iron 

in soil habitats and on plant surfaces foments a furious competition. Under iron-limiting conditions 

PGPB produce low molecular-weight compounds called siderophores to competitively acquire 

ferric ion. Siderophores (Greek: "iron carrier") are small, high-affinity iron chelating compounds 

secreted by microorganisms such as bacteria, fungi and grasses. Microbes release siderophores 

to scavenge iron from these mineral phases by formation of soluble Fe3+ complexes that can be 

taken up by active transport mechanisms. Many siderophores are non-ribosomal peptides, 

although several are biosynthesised independently. Siderophores are also important for some 

pathogenic bacteria for their acquisition of iron. Siderophores are amongst the strongest binders to 

Fe3+ known, with enterobactin being one of the strongest of these. 

- 69 -


PGPR as endophytes 

In addition to rhizosphere and rhizoplane colonization, certain PGPR are reported to be 

endophytes, localized in the intercellular spaces of the root epidermal cells and vascular tissue 

(Chen et al., 1995; Benhamou et al., 1996; Hallmann et al., 1997; M'Piga et al., 1997).Endophytic 

bacteria reside within the living plant tissues without doing substantive harm or gaining benefit 

other than residency (Kado, 1992). Several factors favour endophytic bacteria as potential agents 

of ISR. Endophytes have a natural and intimate association with plants. The internal tissues of 

plants provide a relatively uniform and protected environment in comparison to rhizosphere or 

rhizoplane where ectophytic bacteria must compete for nutrients with other microbes and endure 

fluctuations of temperature and moisture, as well as exposure to ultraviolet radiation on above 

ground surfaces. In spite of these advantages, the potential of bacterial endophytes has only been 

explored to a limited extent. Application of endophytic bacteria by stem injection in cotton plants 

reduced root rot caused by Rhizoctonia solani and vascular wilt caused by F. oxysporum f. sp. 

vasinfectum (Chen et al., 1995). These bacteria move upward and downward from the point of 

application and by colonizing the internal tissues, can exclude the entry of a pathogen in the 

vascular stele. 

PGPR as biocontrol agent 

Plant diseases are responsible for annual crop losses at a total value of more than 200 

billion (Agrios, 2005). Resistant plants and chemicals are often used to control plant diseases. 

Resistance does not exist against all the diseases and the breeding of resistant plants takes many 

years. Moreover, acceptance of genetically engineered resistance is still a sensitive issue in the 

European Union. The use of agrochemicals is negatively perceived by the consumers and 

supermarket chains. It is being increasingly banned by governmental policies. Spontaneous 

control of plant diseases by bacteria in some fields was discovered at several places around the 

world. The use of microbes to control diseases, which is a form of biological control, is an 

environment-friendly approach. The microbe is a natural enemy of the pathogen, and if it produces 

secondary metabolites, it does so only locally, on or near the plant surface, i.e., the site where it 

should act. In contrast, the majority of molecules of agrochemicals do not reach the plant at all. 

Moreover, the molecules of biological origin are biodegradable compared with many 

agrochemicals that are designed to resist degradation by the microbes. The term biocontrol is 

used not only to control diseases in living plants but also to control diseases occurring during the 

storage of fruits (also called post harvest control). Studies on the control of pathogens by 

rhizobacteria usually focus on pathogenic microorganisms. Some rhizobacteria are found active 

against weeds (Floresfargas and O , Hara, 2006) and insects (Siddiqui et al., 2005, Pechy et al., 

2008).Application of PGPR in control of plant diseases ,mechanisms involved and their future 

prospects have been described by Compant et al. (2005). 

Soils in which pathogens cause disease symptoms are called conducive soils. Some soils, 

- 70 -


called suppressive soils, contain bacteria that protect plants against fungal diseases despite the 

presence of disease-causing pathogens in soil. Mixing small amount of suppressive soil with a 

large amount of conducive soil makes the latter soil suppressive. Influence of soil factors and 

culture practices affect antagonistic efficiency of inoculated bacteria on sheath blight of rice 

(Gnanamanickan et al. (1992). Microbial control of plant diseases is a complex process involving 

not only the biocontrol microbe, the pathogen, and the plant, but also the indigenous microflora, 

macrobiota such as nematodes and protozoa, and soil, stonewool, or vermiculite (Thomashow and 

Weller, 1996, Chin-A-Woeng et al., 2003, Compant et al., 2005, Haas and Defago, 2005). To act 

efficiently, microbial control agent should remain active under a large range of conditions, such as 

varying pH, temperature, and concentrations of different ions. These requirements are not easy to 

fulfill. Therefore, it is not surprising that the efficacy of several first-generation commercial 

biocontrol products is not always sufficient (Copping, 2004). 

Mixed Bacterial Inoculants: Concept and Potential for the Future 

Increased use of chemical fertilizer is responsible for progressive deterioration of soil 

health. Reports from various parts of the country such as Punjab and Uttar Pradesh suggest that 

inspite of all efforts, production has come down, which may be correlated with decline in microbial 

biomass and the accumulation of nitrates, nitrites, phosphates and other essential nutrients in the 

soil. In this changed scenario, it is being realized seriously to accept biological means for the 

improvement of not only legumes but for other crops as well. Application of microbial inoculants is 

a low cost ecofriendly technology to enhance crop productivity. Mixed inoculants (combinations 

of microorganisms) that interact synergistically are currently being devised. Microbial studies 

performed without plants indicate that some mixtures allow the bacteria to interact with each other 

synergistically, providing nutrients, removing inhibitory products, and stimulating each other 

through physical or biochemical activities that may enhance some beneficial aspects of their 

physiology. It still has to be demonstrated that these bacterial synergistic effects also benefit plant 

growth. An example of this is Azospirillum, one of the most studied bacteria that associate with 

plants (Bashan and Holguin, 1997a). It may associate with sugar- or polysaccharide-degrading 

bacteria (PDB), establishing a metabolic association where the sugar-degrading bacteria produce 

degradation and fermentation products used by Azospirillum as a carbon source, which in turn 

provides PDB with nitrogen. Other examples are the association between Azospirillum and 

Bacillus that degrades pectin, Azospirillum and Cellulomonas that degrades cellulose, and 

Azospirillum and Emerobacter cloacae that ferments glucose .Plant studies have shown that the 

beneficial effects of Azospirillum on plants can be enhanced by co-inoculation with other 

microorganisms. Co-inoculation, frequently, increases growth and yield, compared to single 

inoculation and provide the plants with more balanced nutrition, and improved absorption of 

nitrogen, phosphorus, and mineral nutrients. Thus, plant growth can be increased by dual 

inoculation with Azospirillum and phosphate-solubilizing bacteria. Azospirillum is also considered 

- 71 -


to be a Rhizobium-"helper" stimulating nodulation, nodule activity, and plant metabolism. 

Challenges with PGPR: One of the challenges of using PGPR is natural variation. It is difficult to 

predict how an organism may respond when placed in the field (compared to the controlled 

environment of a laboratory). PGPR are living organisms and should be able to propagate 

artificially to optimize their viability and biological activity until field application. Like rhizobia, PGPR 

do not live forever in a soil and over time growers will need to re-inoculate seeds to bring back 

their populations. 

Conclusion 

PGPRs are the potential tools for sustainable agriculture and trend for the future. For this 

reason, there is an urgent need for research to clear definition of what bacterial traits are useful 

and necessary for different environmental conditions and plants, so that optimal bacterial strains 

can either be selected and/or improved. Combinations of beneficial bacterial strains that interact 

synergistically are currently being devised and numerous recent studies show a promising trend in 

the field of inoculation technology. 

- 72 -


Implication of PGPR for Rhizospheric Colonization and Plant Growth 

Promotion 

Introduction 

Reeta Goel 


Chemical fertilizers have played a significant role in the green revolution, but their 

unbalanced use has led to reduction in soil fertility and environmental degradation .However, a 

large portion of soluble inorganic phosphate applied to soil as chemical fertilizer is immobilized 

rapidly and becomes unavailable to plants, which is not an environment friendly approach. 

Optimization of a biological phosphate solubilizer in the form of rhizospheric microorganisms 

seems to be a suitable tool to release some of the soil-bound phosphates and reduce the use of 

chemical fertilizers. 

Plant Growth Promoting Rhizobacteria (PGPR) 

The group of bacteria that colonize roots or rhizosphere soil and beneficial to crops are 

referred to as plant growth promoting rhizobacteria (PGPR). Plant growth-promoting rhizobacteria 

(PGPR) are free-living, soil-borne bacteria, which enhance the growth of the plant or reduce the 

damage from soil-borne plant pathogens. PGPR are the rhizospheric bacteria that can enhance 

plant growth by a wide variety of mechanisms like phosphate solubilization, siderophore 

production, biological nitrogen fixation, rhizosphere engineering, production of 1- 

Aminocyclopropane-1- carboxylate deaminase (ACC), quorum sensing (QS) signal interference 

and inhibition of biofilm formation, phytohormone production, exhibiting antifungal activity, 

production of volatile organic compounds (VOCs), induction of systemic resistance, promoting 

beneficial plant-microbe symbioses, interference with pathogen toxin production etc. 

P Solubilization 

Phosphorus (P) is the second most essential nutrient after nitrogen (N) and limits plant 

growth and development. Soil microorganisms are effective in releasing phosphate from total soil 

phosphorus through solubilization and mineralization. Microorganisms solubilized inorganic 

phosphates in soil and making them available to plants is well known. These microorganisms are 

called Phosphate Solubilizing Bacteria (PSB) and they convert insoluble phosphates to soluble 

phosphates by acidification. 

PSB 

PSB bring about the mobilization of insoluble phosphates in the soil and increase plant 

growth under conditions of poor phosphorus availability. These microorganisms also have the 

potential for ecological amelioration of P and thereby improve growth and the establishment of 

plants under low phosphorus availability. These beneficial bacteria enhance plant growth by 

improving soil nutrient status, secreting plant growth regulators and suppressing soil-borne 

pathogens. The use of phosphate solubilizing bacteria as inoculants simultaneously increases P 

- 73 -


uptake by the plant and crop yield. Strains from the genera Pseudomonas, Bacillus and Rhizobium 

are among the most powerful phosphate solubilizers 

Our Contribution 

Experiments 

35 bacterial isolates were originally isolated from Ranichauri and Pithoragarh (Uttarakhand, 

India) rhizospheric soils of legume crops and were screened for qualitative phosphate 

solubilization assay on Pikovskaya agar medium plate. Eight of those isolates were evident by a 

clear halo around the bacterial colony on Pikovskaya agar plates. Further, two potential PSB, 

Chryseobacterium sp. PSR10 and Escherichia coli RGR13 were selected for further studies. On 

the basis of the pot trial study, Chryseobacterium sp. PSR10 strain was selected for field study. 

Results 

Plant growth-promoting activities were found to be stimulated in the presence of microbial 

inoculant Chryseobacterium sp. PSR10. 

A green house study was conducted to evaluate the bioremediation potential and plant 

growth promoting activities of the two potential bacterial strains, Pseudomonas putida 710A and 

Commamonas aquatica 710B. Both were originally isolated from soil samples from the Semra 

mines in Palamau, Jharkhand and were resistant up to 1 mM CdCl 2 and 0.5 mM CdCl 2 , 

respectively. They were screened for P solublization followed by heavy metal analysis. 

Results 

Pseudomonas putida 710A showed better P solubilizing activity, when grown in liquid broth 

supplemented with cadmium at 10 °C. Moreover, the strain was able to reduce Cd accumulation in 

roots and shoots. 

Future Prospects 

‣ Chryseobacterium sp. PSR10 might be used as a convenient, cost-effective and 

ecofriendly PSB. 

‣ Pseudomonas putida 710A strain could be explored for sequestering and as a 

growthpromoting bioinoculant in Cd polluted soil. 

Publications 

‣ Singh AV, Chandra R, Goel, R (2012) Phosphate solubilization by Chryseobacterium sp. 

and their combined effect with N and P fertilizers on plant growth promotion. Archives of 

Agronomy and Soil Science. DOI:10.1080/03650340.2012.664767. 

‣ Rani A, Souche Y, Goel R (2012) Comparative in situ remediation potential of 

Pseudomonas putida 710A and Commamonas aquatica 710B using plant (Vigna radiata 

(L.) wilczek) assay. Ann Microbiol. DOI 10.1007/s13213-012-0545-1. 

Funding Agencies 

‣ DBT 

‣ NBAIM/ICAR 

Collaborators 

‣ Dr. Yogesh Souche : NCCS, Pune 

‣ Dr. Ramesh Chandra : Deptt. of Soil Science, GBPUAT, Pantnagar 

- 74 -


Microbes and Intellectual Property Rights 

H.S. Chawla 

Department of Genetics & Plant Breeding, G.B.P.U.A.&T., Pantnagar- 263 145 (Uttarakhand) 

The WTO was established on 1 st 

January 1995 and is responsible for making and 

enforcing rules for trade between nations. WTO marks a major change in global trade rules. As an 

organization, it replaces the General Agreement on Tariffs and Trades (GATT), which had been in 

existence since 1947. All the agreements annexed to the Agreement establishing the WTO were 

signed as part of a package deal. Member countries did not have the option of choosing some and 

rejecting others. Another important difference with the erstwhile GATT is that WTO has a stronger 

compliance mechanism than the GATT. A member’s failure to meet the obligations can invoke 

retaliation across agreements and sectors (Chawla, 2007). As one of the WTO agreements, 

TRIPS is binding on all member countries of WTO. TRIPS aim at establishing strong minimum 

standards for intellectual property rights (IPRs). 

Intellectual property rights (IPRs) protection plays a key role in getting an advantageous 

position in the competitive world for achieving economic growth. This has become more 

pronounced in the globalized economy with the obligations in the field of IPR in the WTO regime. 

With the globalization of trade and commerce, it has become important to enrich our knowledge 

about IPRs. IPRs are important not only because India as a member is required to accede to the 

conditions of an international agreement but also because they offer possible mechanisms for 

stimulating research, enabling access to technology and promoting enterprise growth with an 

ultimate aim to benefit human population. The importance of IPRs can be gauged from the fact 

that most globally competitive corporations strategically protect their intellectual properties in all 

potential markets/countries by filing patents and other IP arrangements. Although each country 

implements intellectual property laws at the national level, the TRIPS (Trade Related Aspects of 

Intellectual Property Rights) agreement imposes minimum standards on patents and other IPs. As 

a result of the commitments made under the TRIPS Agreement, India has enacted and amended 

their existing norms of IP protection to be TRIPS compliant, for which the deadline was December, 

2004. 

IPRs can be defined as the rights given to people over the creation of their minds. They 

usually give the creator an exclusive right over the use of his/her creation for a certain period of 

time. Intellectual property includes patents, copyrights, trademarks, geographical indications, 

industrial designs, integrated circuits and trade secrets. The protection of IPRs is binding and 

legally enforceable. 

IPRs have been created to ensure protection against unfair trade practice. Owners of IP 

are granted protection by a state and/or country under varying conditions and periods of time. This 

protection includes the right to: (i) defend their rights to the property they have created; (ii) prevent 

others from taking advantage of their ingenuity; (iii) encourage their continuing innovativeness and 

- 75 -


creativity; and (iv) assure the world a flow of useful, informative and intellectual works. 

Patents 

A patent is a government granted exclusive right to an inventor for the development of a 

new product or process involving an inventive step which is capable of industrial application. This 

will prevent others from practicing i.e. making, using or selling the invention. A patent is a personal 

property, which can be licensed or sold like any other property. The purpose of a patent is to 

encourage and develop new innovations. The Patent Law recognizes the exclusive right of a 

patentee to gain commercial advantage out of his invention. There are three criteria of novelty, 

inventiveness and usefulness to issue a patent for the innovation. In the patent adequate 

disclosure should be made so that others can also work on it. It should have the features: i) be a 

written description; ii) enables other persons to follow; iii) adequate and iv) deposit mechanism. 

The present law, Patents Act 1970, amendment 2005 is effective from January 1, 2005. Process 

and product patents on all items including food, agro-chemical and pharmaceuticals have been 

allowed making The Patents Act fully TRIPS compliant. 

The patent system was developed as a means to reward inventions which would be useful 

to the society. However, in order to ensure the interests of society, as per the Indian Patents Act, 

certain things have been excluded from the purview of patentability (Anonymous (2011). The 

sections relevant to the title under consideration which are excluded from patentability are: 

Section 3(d): the mere discovery of any new property or mere new use for a known substance 

or the mere use of a known process, machine or apparatus unless such known process results 

in a new product or employ at least one new reactant; 

Section 3(e): a substance obtained by merely admixture resulting only in the aggregation of 

the properties of the components thereof or a process for producing such substance: 

Section 3(i): any process for medicinal, surgical, curative, prophylactic (diagnostic therapeutic) 

or other treatment of human beings or any process for a similar treatment of animals to render 

them free of disease or to increase their economic value or that of their products: 

Section 3(j): plants and animals in whole or any part thereof other than microorganisms but 

including seeds, varieties and species and essentially biological processes for production or 

propagation of plants and animals: 

Section 3(p): an invention which in effect, is traditional knowledge or which is an aggregation 

or duplication of known properties of traditionally known component or components: 

The first patent on living organism was granted to Dr Chakrabarty in 1980 for a new microorganism 

Pseudomonas which had four plasmids and therefore more useful in dispersing oil slicks 

than the natural organism containing only one such plasmid. US Supreme Court decided that 

microorganism should not be precluded from patentability for the objection raised by USPTO on 

the basis of “product of nature”. This precedent is being followed even today to define the 

patentability of microorganisms. 

- 76 -


Microorganisms per se can be claimed for protection provided they are not mere discovery 

of organisms. It is mandatory to deposit the biological material in International Depositary Authority 

(IDA). In India, Institute of Microbial Technology (IMTECH), Chandigarh is a recognized IDA for 

some category of micro-organisms. If an applicant mentions a biological material in the patent 

specification then disclosure requirements prescribed for biological materials have been notified in 

the list of the Central Government or for indicating its source and geographical origin [Section: 

10,4(d)]. 

The purpose of a patent is to promote the progress of science and useful arts. The patent 

law promotes this progress by giving the inventor the right of exclusion. In exchange for this right 

to exclude others, the inventor must disclose all details describing the invention, so that when the 

patent period expires, the public may have the opportunity to develop and profit from the use of 

invention. A patent is enforced in the country which issues it, meaning thereby territorial in nature. 

For each country a separate application is to be filed in that country where protection is sought. 

Plant patents 

Plant patents are obtainable in US and Japan. The US Plant Patent Act of 1930 (PPA) 

granted property rights for privately developed plant varieties of asexually reproducing plants. 

These rights were extended to new and distinct asexual varieties for a period of seventeen years. 

Advances in breeding technology provided the momentum for the 1970 Plant Variety Protection 

Act (PVPA). The PVPA provided protection for sexually reproducing plants, including seed 

germination. In 1980 Diamond vs. Chakrabarty case set in motion the trend towards the legal 

acceptance of the commodification of germplasm. Commodification is the process whereby an 

object, whether tangible, such as seed, or intangible, such as knowledge about the seed, is turned 

into a commodity, i.e. something that acquires an economic worth and can be bought and sold. 

US Supreme Court in Diamond vs. Chakrabarty case decided that microorganism should not be 

precluded from patentability for the objection raised by USPTO on the basis of “product of nature”. 

The court held that a live, man made bacterium was patentable under the PPA and the ‘product of 

nature’ objection therefore failed and the modified organisms were held patentable. In the Hibberd 

case (1985), involving a tryptophan-overproducing mutant, the patent office ruled that plants could 

be patented and there is no distinction between asexually and sexually propagated plants. 

Following the principle established in the Chakrabarty case, it was decided that normal US utility 

patents could be granted for other types of plant e.g. genetically modified plants. Plant patents 

have been granted by European Patent Office (EPO) from 1989. But in 1995, EPO severely 

restricted the scope of Plant Genetic Systems (Belgium) patent on herbicide resistant plants and 

allowed claims only on the herbicide resistant gene and the process used in the generation of 

plants. In Japan, plant patents are allowed, but there are some disputes over territorial rights. Life 

forms of plants and animals except microorganisms are not patentable in India. In pursuance to 

the TRIPS agreement, India has enacted “Protection of Plant Varieties and Farmers’ Rights” 

- 77 -


(PPV&FR) Act, 2001, a sui generis system of plant variety protection which has been described in 

detail separately (Chawla, 2005). 

Plant Variety Protection in India 

India and so many other countries do not protect plants by strict patenting system. But 

there is a mandate in the TRIPS agreement that plant varieties must be protected. In pursuance to 

the TRIPS agreement, India has enacted “Protection of Plant Varieties and Farmers’ Rights” 

(PPV&FR) Act, 2001, a sui generis system of plant variety protection. The PPV&FR Act 2001 

provides protection to Newly bred varieties; Extant varieties – The varieties which were released 

under Indian Seeds Act, 1966 and have not completed 15 years as on the date of application for 

their protection; Farmers’ varieties – The varieties which have been traditionally cultivated, including 

landraces and their wild relatives which are in common knowledge, as well as those evolved by 

farmers; Essentially derived varieties; and Transgenic varieties. To qualify for registration under the 

act, a new variety has to conform to the criteria of novelty (N), distinctiveness (D), uniformity (U) and 

stability (S). Besides, a denomination has to be given for the registration of variety (Anonymous, 

2010). 

The Act had laid down the norms for registration of plant varieties, fee structure, provisions 

of opposition, DUS testing of material, etc. Intellectual Property Management Centre of G.B. Pant 

University of Agric. & Tech., Pantnagar has taken the lead by registering three farmers’ varieties of 

rice namely Tilakchandan, Hansraj and Indrasan on behalf of the farmers and for the benefit of 

farmers. 

Once the variety has been tested for its features then the Registrar of the Authority will 

issue the certificate of registration. It shall have the validity of nine years initially in case of trees 

and vines with renewal up to a period of 18 years. For other crops certificate of registration will be 

issued for six years initially with renewal up to 15 years. In case of extant varieties the validity 

period is 15 years from the date of notification of that variety by the Central Government under 

section 5 of the Seeds Act 1966. 

Copyright 

Copyright protects only the form of expression of ideas, not the ideas themselves. The 

creativity protected by copyright law is creativity in the choice and arrangement of words, musical 

notes, colors, shapes and so on. Copyright was created to provide protection to composers, 

writers, authors and artists to protect their original works against those who copy; those who take 

and use the form in which the original work was expressed by the author. Computer 

software/program is another mode of expression. A computer program is produced by one or 

more human authors but, in its final mode or form of expression it can be understood directly only 

by a machine (the computer) not by human readers. In India, The Copyright Act 1957 as amended 

in 1994 is in force. The Copyright protection of computer software is under the Information 

Technology Act, 2000 (Chawla and Singh, 2005). 

- 78 -


Trademark 

A trademark is a symbol that helps to distinguish one product or company from another. 

Symbols help the consumer identify products and/or a company and include designs, shapes, 

numbers, slogan, smell, sound or anything that helps the consumer to identify the products and/or 

companies. In research, laboratory equipments bear trademarks that are well known to workers in 

their field. Trademark law, unlike patent or copyright law, confers a perpetual right. So long as the 

trademark continues to identify a single source, anyone who uses a very similar mark may be 

liable for trademark infringement. The perpetual right of trademarks depends on the use. The 

basic idea of ‘use it or lose it’ is essential to preserving trademark rights. A company cannot 

register a trademark and then not use it. The product for which the trademark was registered must 

be used commercially. 

Trademark rights are so important that multinational companies spend large amount of 

money to maintain their respective trademarks around the world. Every country has different 

trademark laws. However, there are agreements to ensure that a company’s trademark in one 

country is protected in another country. India has a Trade Marks Act, 1999. In this category there 

are certification marks like AGMARK, FPO, ISO etc.; service marks viz. LIC, SBI, PNB, etc. and 

collective marks viz. INTUC, AA, etc. 

Other forms 

There are other forms of IPR protection viz. Geographical Indications of Goods, Industrial 

design, Trade secret and Layout designs of integrated circuits. 

REFERENCES 

• Anonymous, 2010. The Protection of Plant Varieties and Farmers’ Rights Act, 2001 and Rules, 

Universal Law Publishing Co., Delhi, 2010. 

• Chawla, H.S., 2007. Intellectual Property Rights. J. Eco-friendly Agriculture, 2(2): 103-112 

• Chawla, H.S. and Singh, A.K., 2005. Intellectual Property Rights. Vol II: Copyrights, Trade Marks, 

Trade Secrets and Geographical Indications. Pantnagar University Press, pp-75 

• Anonymous (2011). The Patents Act, 1970 along with The Patent rules, 2003 as amended by The 

Patents (Amendment) Rules, 2005, Universal Law Publishing Co., Delhi 

• Chawla, H.S. (2005). Patenting of biological material and biotechnology. J Intellectual Property 

Rights, 10: 44 – 51 

- 79 -


Induced Resistance: A Novel Strategy for Plant Protection against 

Diseases 

Introduction 

P.K. Shrotria 

Department of Genetics & Plant Breeding, G.B.P.U.A.&T., Pantnagar- 263 145 (Uttarakhand) 

The resistance in plants induced by pathogens was first recognized by Ray (1901) and 

Beauverie (1901). Convincing evidences however were obtained only in the 1960s, when 

reproducible models using tobacco plant were developed (Cruickshank and Mandryk, 1960). The 

induced resistance may diminish the use of toxic chemicals for disease control, and thus could be 

proposed as an alternative, non-conventional, non-biocidal and ecologically-friendly approach for 

plant protection and hence for sustainable agriculture. 

Induced resistance 

When a plant is inoculated with a pathogen (“primary inoculation”), and after a time interval 

is subjected to a secondary (“challenge”) inoculation, reduced disease symptoms develop, i.e. the 

induced plant becomes more resistant than the normal, non-induced plant. The term 

“immunization” has been used to denote treatments that enhance the defensive capacity of plants. 

Systemic acquired resistance (SAR) and Localized acquired resistance (LAR) 

In the early 1960s Ross, as a result of his carefully controlled laboratory experiments with 

tobacco-TMV system, coined the terms for hypersensitive reaction to TMV i.e. forming of small 

necrotic lesions following TMV inoculation. Inoculation of the same leaf after a few days resulted in 

development of smaller-sized and less numerous lesions, i.e. the disease severity was reduced. 

These phenomena were referred to as LAR (Ross, 1961a). Ross succeeded also in inducing 

resistance to TMV in distant upper leaves of tobacco by primary inoculation of lower leaves with 

the virus, a phenomenon referred to as SAR (Ross, 1961b). 

Induced systemic resistance (ISR) 

Recently, the term “induced systemic resistance (ISR) has been introduced to designate 

the resistance induced in leaves of plants by inoculation of roots with non-pathogenic 

rhizobacteria. First described in Arabidopsis plants, inoculated with the root-colonizing 

nonpathogenic bacteria Pseudomonas fluorescens; leaves of these plants exhibited resistance 

against the bacterial leaf pathogen Pseudomonas syringae pv. Tomato (Pieterse et al., 1998). 

Rhizobacteria-mediated ISR has also been demonstrated against fungi, bacteria and viruses in 

Arabidopsis, bean, carnation, cucumber, radish, tobacco and tomato (Van Loon et al., 1998). 

Inducers of resistance 

A multitude of factors are reported to induce resistance in plants: pathogens (fungi, 

bacteria, viruses) causing hypersensitive necrotic reaction (HR); elicitors of biotic origin; abiotic 

elicitors, i.e. chemical products, such as benzothiadiazole (BTH), beta-aminobutyric acid (BABA), 

2,6-dichloroisonicotinic acid (INA), salicylic acid, inorganic salts, etc. The use of chemicals as 

- 80 -


inducers of resistance is an area of extensive work. Safe application in greenhouse and fields 

conditions viz. no direct toxicity to pathogens; no toxicity to plants and animals; no negative effects 

on plant growth, broad spectrum of defense, long lasting protection; low economical cost are the 

features required in chemical inducers. The application of chemical inducers of resistance is 

means of disease control by providing both effective and ecologically-friendly plant protection. A 

large array of chemical products are shown to induce SAR in tobacco viz. salicylic acid, 

isonicotinic acid (INA), benzothiadiazole (BTH) and beta-aminobutyric acid (BABA). Chemicallyinduced 

SAR was found to be effective against fungi, bacteria and viruses. The practical 

application of chemicals as resistance inducers is mainly based on their systemic effect, i.e. on 

SAR expression in plants. The non-protein amino acid β-aminobutyric acid (BABA) induces 

resistance without the expression of PR-genes. BABA can induce resistance to H. parasitica in 

Arabidopsis independent of SA, JA or ET, through a signaling pathway that requires abscisic adid 

(ABA) and involves priming for callose deposition, 

Mechanisms of SAR 

A cascade of molecular and biochemical events underlies the expression of SAR. It is 

initiated by perception of inducers (pathogens, chemicals) resulting in generation of signal 

molecules translocated at long distance, and switching on the diverse processes contributing to 

the development of the defense potential of plants realized upon secondary inoculation. 

Perception of inducers is effectuated through binding of pathogen-derived molecules (elicitors) or 

chemical products with receptor sites on plant membranes or cell walls. Salicylic acid is commonly 

recognized as a signal molecule or a prerequisite for signal production in SAR. The term “SARgenes” 

is used to collectively designate this family of nine genes whose expression is correlated 

with the onset of SAR. For TMV-infected tobacco the SAR-genes code for PR-1 proteins, betaglucanase 

(PR-2), chitinase (PR-3), hevein-like protein (PR-4), thaumatin-like and osmotin-like 

proteins (PR-5), PR-1 (basic), basic class III chitinase, acidic class III chitinase, and PR-Q’ (Ward 

et al., 1991). 

Terminology 

Because of the enhanced protection afforded by induction of resistance through exposure 

to a pathogen, the term ‘induced resistance’ has been used synonymously with ‘acquired 

resistance’, ‘acquired immunity’ and ‘immunization’. Induced disease resistance has been adopted 

as a general term and defined as ‘the process of active resistance dependent on the host plant’s 

physical or chemical barriers, activated by biotic or abiotic agents (inducing agents)’ (Kloepper et 

al., 1992). Resistance to primary infection can result from the presence of preformed defensive 

barriers, but in inducible resistance mechanisms, the infecting pathogen triggering defense 

responses through the release of elicitors which, in turn, lead to the expression of novel antipathogenic 

activities . The resistance is expressed only as a result of the specific recognition 

between plant and pathogen. The term ‘acquired resistance’, advocated by Ross, points to a 

- 81 -


change in the physiology of the plant resulting from an added property. Acquired resistance 

obviously is not the phenomenon that resistance was not present, but acquired only as a result of 

primary infection. 

Association of pathogenesis-related proteins with induced resistance 

Whereas induction of phytoalexins and cell wall rigidification are local reactions, 

accumulation of pathogenesis-related proteins (PRs) extends into non inoculated plant parts that, 

upon challenge, exhibit acquired resistance. PRs have been found to be invariably linked to 

necrotizing infections giving rise to SAR, and has been taken as a marker of the induced state. 

Together the PRs form a set of pathogen-induced proteins that may be considered as stress 

proteins. PRs may be considered as stress proteins produced in response to, particularly 

necrotizing, infections by viruses, viroids, fungi and bacteria, and thought to function in the 

acquired resistance against further infection. They accumulate in plant tissues to levels that are 

easily detectable on gels by general protein stains. The inducible PRs are mostly acidic proteins 

that are secreted into the intercellular space of the leaf. In induced plants the accumulated 

intercellular proteins form the first line of defense to a challenging pathogen and, if this fails and 

the tissue is disrupted, the release of the vacuolar PRs functions as a second line, engulfing the 

pathogen with lytic enzymes (Mauch and Staehelin, 1989). 

Systemic signaling by SA 

For expressing a HR and developing SAR, SA acts as a signal in the induction of acquired 

resistance. SA is required for the expression of resistance, as well as for the enhanced defensive 

capacity of tissues with acquired resistance. Induction of acquired resistance and PRs is often 

accomplished by spraying plants with SA solution and assaying of the sprayed leaves. When SA 

was watered on the soil, acquired resistance was apparent in upper leaves, indicating that SA was 

absorbed by the roots and transported throughout the plant. 

Induction of systemic resistance by non-pathogenic micro-organisms 

Well-studied biologically-induced disease resistance occurs after root colonization by 

selected strains of non-pathogenic Pseudomonas spp. This type of resistance is generally called 

rhizobacteria-induced systemic resistance (Pieterse et al. 1996). The expression of rhizobacteriamediated 

ISR was shown to be independent of the presence of SA or enhanced PR-gene 

expression. Although the terms SAR and ISR are synonymous for convenience we distinguish 

between pathogen- and rhizobacteria-induced resistance by using the term SAR for the pathogeninduced 

type and ISR for the rhizobacteria-induced type of resistance. 

Plants produce exudates and lysates at their root surface, where rhizobacteria are 

attracted in large numbers. Selected strains of non-pathogenic rhizobacteria are named plant 

growth-promoting rhizobacteria (PGPR), because they possess the capability to stimulate plant 

growth. Pseudomonas spp. are among the most effective PGPR. They have been shown to be 

responsible for the reduced activity of soil-borne pathogens. Apart from such direct antagonistic 

- 82 -


effects on soil-borne pathogens, some PGPR strains are also capable of reducing disease 

incidence in above-ground plant parts through plant-mediated mechanisms. The enhanced 

defensive capacity elicited by Pseudomonas fluorescens CHA0 in tobacco might be fully explained 

by the bacterial production of SA, which could elicit a SAR response. 

Combining ISR and SAR to improve biocontrol of plant diseases 

Detailed knowledge of the molecular mechanisms underlying induced disease resistance 

will be instrumental in developing biologically-based, environmentally-friendly, and durable crop 

protection. Simultaneous activation of ISR and SAR may confer differential protection against 

different types of pathogens (Ton et al. 2002). Thus, combining both types of induced resistance 

can protect the plant against a complementary spectrum of pathogens, and can even result in an 

additive level of induced protection against pathogens that are resisted through both the JA/ETand 

the SA- dependent pathways. 

Fig. 1. (a) Systemic acquired resistance, induced by the exposure of root or foliar tissues to abiotic or biotic 

elicitors, is dependent of the phytohormone salicylate (salicylic acid), and associated with the 

accumulation of pathogenesis-related (PR) proteins. 

(b)Induced systemic resistance, induced by the exposure of roots to specific strains of plant growthpromoting 

rhizobacteria, is dependent of the phytohormones ethylene and jasmonate (jasmonic 

acid), independent of salicylate, and is not associated with the accumulation of PR proteins (or 

transcripts). 

Molecular basis of resistance 

The advent of molecular biology has enabled the genes that confer disease resistance to 

be analyzed at a molecular level. The majority of isolated cereal R genes encode proteins 

containing a central domain with a nucleotide binding site (NBS), which binds either ATP or GTP, 

and a carboxyterminal domain consisting of a series of degenerate leucine-rich repeat residues 

(LRR). These so-called NBS-LRR genes are a super family of R genes present in both 

monocotyledonous and dicotyledonous species. NBS-LRR proteins have been shown to provide 

plant recognition of fungal and bacterial pathogens in cereals, but they also recognize viral, 

nematode and insect species that parasitize dicotyledonous plants. How R genes recognize 

pathogen avirulence products at a molecular level? This recognition process can be envisaged as 

a specific receptor– ligand interaction that subsequently leads to activation of a defence response. 

- 83 -


Lack of interaction suggests either indirect recognition of these avirulence products by R proteins, 

or alternatively these R proteins recognize avirulence product/host protein complexes, a concept 

termed ‘the guard hypothesis’ (Bogdanove, 2002). Research has focused on the elicitor molecules 

released during the early stages of the plant–pathogen interaction, and on the signaling pathways 

used to trigger defenses locally and systemically. The elicitors examined include carbohydrate 

polymers, lipids, and glycoproteins, and are either secreted by microorganisms or derived from the 

cell walls of fungi, bacteria, or plants. 

Signal transduction in SAR 

Systemic acquired resistance (SAR) refers to a distinct signal transduction pathway that 

plays an important role in the ability of plants to defend themselves against pathogens. After the 

formation of a necrotic lesion, either as a part of the hypersensitive response (HR) or as a 

symptom of disease, the SAR pathway is activated. SAR activation results in the development of a 

broad-spectrum, systemic resistance. SAR can be distinguished from other disease resistance 

responses by both the spectrum of pathogen protection and the associated changes in gene 

expression. Associated with SAR is the expression of a set of genes called SAR genes. When 

SAR is activated, a normally compatible plant-pathogen interaction (i.e., one in which disease is 

the normal outcome) can be converted into an incompatible one. Conversely, when the SAR 

pathway is incapacitated, a normally incompatible interaction becomes compatible. A number of 

biochemical and physiological changes have been associated with pathogen infection. These 

include cell death and the oxidative burst, deposition of callose and lignin, synthesis of 

phytoalexins and novel proteins. A protein is classified as a SAR protein when its presence or 

activity correlates tightly with maintenance of the resistance state. Analysis of SAR proteins 

showed that many belong to the class of pathogenesis-related (PR) proteins, which originally were 

identified as novel proteins accumulating after TMV infection of tobacco leaves. 

SA plays a key role in both SAR signaling and disease resistance. The leve1 of SA was 

found to increase by severa1 hundred-fold in tobacco or cucumber after pathogen infection, and 

this increase was shown to correlate with SAR. The increased in concentration of SA and the 

establishment of enhanced disease resistance has been observed not only in tobacco and 

cucumber but in other plants as well. 

- 84 -


Signal transduction occurs when an extracellular signaling molecule activates a cell surface 

receptor. In turn, this receptor alters intracellular molecules creating a response. There are two 

stages in this process. A signaling molecule activates a specific receptor protein on the cell 

membrane. A second messenger transmits the signal into the cell, eliciting a physiological 

response. Signal transduction involves the binding of extracellular signalling 

molecules and ligands to cell-surface receptors that trigger events inside the cell. The combination 

of messenger with receptor causes a change in the conformation of the receptor, known 

as receptor activation. Intracellular signaling cascades can be started through cell-substratum 

interactions; examples are the integrin that binds ligands in the extracellular matrix and steroids. 

Most steroid hormones have receptors within the cytoplasm and act by stimulating the binding of 

their receptors to the promoter region of steroid-responsive genes. 

Role of SA as translocated signal 

Pathogen infection results in significant amounts of SA in the phloem sap of both cucumber 

and tobacco. Additionally, in-vivo SA-labeling studies provide evidence that SA produced in the 

leaves of TMV-infected tobacco or TNV-infected cucumber is transported throughout the plant and 

accumulates in uninfected tissues. In fact, as much as 70% (tobacco) and 50% (cucumber) of the 

increase in SA in uninfected tissue of pathogen-inoculated plants results from SA translocation from 

infected leaves to uninfected leaves. Two lines of evidence however suggest that SA is not the long 

distance signal. First, in cucumber, primary leaves infected with P. syringae can be removed 6 hrs 

after inoculation, which is before SA accumulates in the phloem, without affecting the systemic 

increase of SA or SAR gene expression (Rasmussen et al., 1991). In grafted tobacco plants, TMV 

inoculation of NahG rootstocks resulted in very little SA accumulation in infected tissue, compared 

with a 185-fold increase for wild-type (Xanthi) plant. These results suggest that either SA is not the 

long distance signal or very small amounts of SA in infected leaves are sufficient for full SAR 

induction. Even though SA is not likely to be the translocated signal that triggers SAR in dista1 plant 

organs, it is essential for SAR signal transduction. These findings indicate that SA is an essential 

signal in SAR and that it is required downstream of the long distance signal. 

Modes of action of SA 

It has been proposed that H 2 0 2 acts as a second messenger of SA in SAR signaling. A SA 

binding protein was identified as catalase; SA was found to inhibit the catalase activity of this 

protein, leading to elevated levels of H 2 0 2 . Furthermore, H 2 0 2 was found to cause induction of PR- 

1 gene expression and was postulated to induce SAR (Chen et al., 1993, 1995). 

Recent reports, however, indicate that for H 2 0 2 to function as a signaling agent of SA, H 2 0 2 

levels should increase in uninfected leaves of tobacco plants during SAR activation. In the 

uninfected leaves of inoculated plants, SAR gene expression and the establishment of SAR did 

not correlate with an increase in H 2 0 2 levels. More recent reports further suggest that very high 

levels of SA (1 mM) inhibit the in-vitro activity of a variety of heme-iron-containing enzymes, 

- 85 -


including catalase. In infected leaves, high concentrations of SA around the site of infection may 

inhibit catalase and other oxidoreductases. lnhibition of catalase activity could prolong the half-life 

of H 2 0 2 and lead to an amplification of the oxidative burst. The oxidative burst may trigger a variety 

of local defense responses including programmed cell death during the HR as well as defense 

gene expression and synthesis of SA in adjacent cells. This would create a runaway cycle leading 

to high levels of both SA and H 2 0 2 at the site of pathogen attack. 

Chemical activators of SAR 

SAR was first described as a response to pathogen infection. Subsequently, it has been 

found that treatment of plants with low molecular weight molecules can also induce SAR. The use 

of chemicals to activate SAR provides nove1 alternatives for disease control in agronomic systems 

as well as tools for the elucidation of the SAR signal transduction cascade. To be considered an 

activator of SAR, a chemical should exhibit three characteristics first, the compound or its 

significant metabolites should not exhibit direct antimicrobial activity; second, it should induce 

resistance against the same spectrum of pathogens as in biologically activated SAR; and third, it 

should induce the expression of the same marker genes as evident in pathogen-activated SAR. 

Severa1 chemicals or extracts, including silicon, phosphate, 2-thiouracil, polyacrylic acid, nucleic 

acids, and fosethyl Al, have been reported as potential activators of resistance but have failed to 

fulfill the above criteria (Kessmann et al., 1994). Other compounds, such as DL-8 aminobutanoic 

acid or probenazole, have been shown to slightly induce either PR-1 gene expression or 

resistance against one or two pathogens, but activation of bona fide SAR has not been 

demonstrated. To date, SA is the only plant-derived substance that has been demonstrated to be 

an inducer of SAR. The chemicals 2, 6- dichloroisonicotinic acid and its methyl ester (both referred 

to as INA) were the first synthetic compounds shown to activate SAR, thus, providing broadspectrum 

disease resistance. Recently, the synthetic chemical benzo (l,2,3) thiadiazole-7- 

carbothioic acid S-methyl ester (BTH) was demonstrated to be a potent SAR activator. 

Mechanisms of mycorrhiza-induced resistance 

Plants have established a mutualistic association known as arbuscular mycorrhizas (AM) 

with certain soil fungi. Arbuscular mycorrhiza forming fungi (AMF) are obligate biotrophs because 

they rely on their host plant to proliferate and survive. AM deal with the reduction of incidence 

and/or severity of soil-borne diseases mainly root rot or wilting caused by fungi such as 

Rhizoctonia, Fusarium, or Verticillium, and root rot caused by oomycetes including Phytophthora, 

Pythium, and Aphanomyces. A reduction in the deleterious effects by parasitic nematodes such as 

Pratylenchus and Meloidogyne has also been reported 

Different mechanisms operative simultaneously, have been shown to play a role in plant 

protection by AMF, namely, improved plant nutrition, damage compensation, competition for 

colonization sites photosynthates, changes in the root system, changes in rhizosphere microbial 

populations and activation of plant defense mechanisms. There is evidence for the accumulation 

- 86 -


of defensive plant compounds related to mycorrhization, although to a much lower extent than in 

plant–pathogen interactions. 

The identification of strigolactones, known to stimulate seed germination of parasitic plants, 

as host recognition compounds for AMF has uncovered a possible mechanism mediating the 

protector effect of AM against parasitic plants. Mycorrhizal plants by exudating lower amounts of 

strigolactones are unfavorable to parasitic plant seed germination. Salicylic acid (SA) co-ordinates 

defense mechanisms that are generally effective against biotrophic pathogens, whereas 

jasmonates (JA) regulate wounding responses and resistance against necrotrophs. As obligate 

biotrophs, AMF share similarities with biotrophic pathogens. Thus, their sensitivity to SA-regulated 

defenses is likely. Indeed, exogenous SA application delays mycorrhizal colonization. 

Fig 3. (a)Upon attacker recognition, the plant produces the defense-related signals JA, ET, and 

SA in different proportions.(b) Mycorrhiza formation primes the tissues for a quicker and 

more effective activation of JA-dependent defense responses upon attack, 

Factors influencing the expression of induced resistance 

Effects of genotype 

In monocots, resistance activated is very long lasting, whereas the lasting effect is less 

pronounced in dicots. Reduction in powdery mildew on barley following treatment with culture 

filtrate of B. subtilis was cultivar specific and was most marked in partially resistant cultivars. 

Extent of induced resistance was most effective in lines with the Mla7 gene and least effective in 

lines with the Mla13 gene. 

Environmental effects 

Exposure to abiotic stress can influence plant resistance to pathogens. Ayres (1984), 

proposed two possible reasons for this phenomenon. The first is the possibility that the negative 

effects of pathogens and abiotic stress might be additive and second possibility is that abiotic 

stress might alter plant resistance to pathogen infection, leading to enhanced resistance. Water 

stress has been reported to increase susceptibility to foliar pathogens also has been shown to 

enhance resistance to powdery mildew in older leaves of barley, grown in dry soil. Appropriate 

timing and frequency of application, use in conjunction with appropriate-dose of fungicides, 

combinations of agents that induce resistance with fungicides or biological control agents, has 

been shown to provide effective disease control. 

- 87 -

REFERENCES 


• Ayres, PG (1984). The interaction between environmental stress injury and abiotic disease 

physiology. Annu. Rev. Phytopathol. 22:53-75. 

• Beauverie J (1901). Essais d’immunisation des végétaux contre les maladies cryptogamiques. CR 

Acad Sci Paris. 133: 107-110, 1901. 

• Bogdanove AJ. (2002). Protein-protein interactions in pathogen recognition by plants. Plant 

Molecular Biology 50: 981–989. 

• Chen, Z, Silva, H, and Klessig, DF (1993). lnvolvement of reactive oxygen species in the 

induction of systemic acquired resistance by salicylic acid in plants. Science 242: 

883-886. 

• Chen, ZX, Malamy, J, Henning, J, Conrath, U, Sanchezcasas, P, Silva, H, Ricigllano, J, and 

Klessig, DF (1995). Induction, modification, and transduction of the salicylic acid 

signal in plant defense responses. Proc. Natl. Acad. Sci. USA 92: 4134-4137. 

• Kessmann, H, Staub, T, Hofmann, C, Maetzke, T, Herzog, J, Ward, E., Uknes, S., and Ryals, J 

(1994). lnduction of systemic acquired resistance in plants by chemicals. Annu. 

Rev. Phytopathol 32:439-459. 

• Kloepper JW, Tuzun S and Kuc JA(1992) Proposed definitions related to induced disease 

resistance. Biocontrol Science and Technology 2: 349–351 

• Mauch F and Staehelin LA (1989) Functional implications of the subcellular localization of 

ethylene-induced chitinase and β 1,3-glucanase in bean leaves. The Plant Cell 1: 

447–457 

• Pieterse CMJ, Van Wees SCM, Hoffland E, Van Pelt JA and Van Loon LC (1996) Systemic 

resistance in Arabidopsis induced by biocontrol bacteria is independent of salicylic 

acid accumulation and pathogenesis-related gene expression. The Plant Cell 8: 

1225–1237 

• Pieterse CMJ, Van Wees SCM, Van Pelt JA, Knoester M, Laan R, Gerrits H, Weisbeek PJ, Van 

Loon LC (1998) A novel signaling pathway controlling induced systemic resistance 

in Arabidopsis. The Plant Cell 10, 1571-1580 

• Ray J (1901). Les maladies cryptogamiques des végétaux. Rev Gen Bot. 13: 145-151. 

• Ross AF (1961a) Localized acquired resistance to plant virus infection in hypersensitive hosts. 

Virology. 14: 329-339 

• Ross AF (1961b). Systemic acquired resistance induced by localized virus infection in plants. 

Virology. 14: 340-358 

• Rasmussen JB, Hammerschmidt R and Zook MN (1991) Systemic induction of salicylic acid 

accumulation in cucumber after inoculation with Pseudomonas syringae pv. 

syringae. Plant Physiology 97: 1342–1347 

• Ton J, Van Pelt JA, Van Loon LC, Pieterse CMJ (2002). Differential effectiveness of salicylatedependent 

and jasmonate/ethylene-dependent induced resistance in Arabidopsis. 

Molecular Plant-Microbe Interactions 15, 27-34 

• Van Loon LC, Bakker PAHM, Pieterse CM. (1998) Systemic resistance induced by rhizosphere 

bacteria. Ann Rev Phytopathol. 36: 453-458 

• Ward ER, Uknes SJ, Williams SC, Dincher SS, Wiederhold DL, Alexander DC, Ahl-Goy P, 

Métraux J-P, Ryals JA (1991) Coordinate gene activity in response to agents that 

induce systemic acquired resistance. The Plant Cell 3: 1085-1094 

- 88 -


Characterization of Macro- and Meteorological Variables for Disease 

Management 

Introduction 

H.S. Kushwaha 


Initiation and progress of plant diseases is the outcome of interaction of 

four vital 

elements viz. Host (susceptibility), Pathogen (Virulence), Environment (Favourable) and time 

(Duration of interaction). These four elements form the " Disease Pyramid " and if these arms 

representing four elements can be measured / quantified, the volume of Pyramid will be a 

measure of disease produced. All these four elements are vital, but the role of environment 

become more important as it influences both host as well as the Pathogen. The severity and 

the extent of this interaction is markedly affected by the environment and the element of time. Not 

only the growth of the host is affected by environmental factors like air temperature, leaf 

temperature, 

relative humidity, wind, precipitation, duration of leaf wetness, intensity and 

duration of radiation, but also they have profound influence on Pathogen and disease 

development. The amount of primary inoculums present is important for subsequent disease 

development. The climatic conditions significantly influence dormancy of plant pathogens and 

therefore, the plant inoculums, when growth commences. Apart from the biological factors, the 

micro-meteorological factors such as duration of leaf wetness, duration and intensity of rain, 

wind speed and its direction within and above the crop canopy play a very important role in 

release and dispersal of the pathogens. 

The plant surface is linked to the environment through the flow of energy between them. 

Humidity conditions and specially dew affects the growth and development of many phytopathogens, 

especially the fungal organisms. The temperature of the surface is the equilibrium 

temperature at which the sensible and latent heat fluxes from the surface equal the net gain by 

radiation. Leaf temperature is, therefore, sensitive to any changes or differnces in the levels of 

exchange. Each leaf or part of a leaf has its own equlibrium level and in this way has a unique 

microclimate responsible for disease outbreaks. 

Environment is a complex phenomenon having both biotic as well as abiotic 

components. We study the physical parameters as weather. Weather can be defined as physical 

state of atmosphere at a particular location at a given time and it is highly dynamic phenomenon. 

On the other hand the climate is defined as average / aggregate weather conditions of a locality. 

The process of disease development is greatly influenced by the weather changes in the close 

vicinity of Host-Pathogen interaction. Thus a measurement of microclimatic parameters gives real 

insight in the Host - Pathogen interaction and it is the outcome (i.e. The Plant Disease). 

2. Macro- and Micro-meteorological variables and brief description of their measurement 

The major macro and micrometeorological variables which are important from the point of 

- 89 -


view of disease development are maximum and minimum air temperatures; relative humidity; wind 

speed and its direction; precipitation; intensity and duration of solar radiation; duration of leaf 

wetness. It is also important to distinguish between macroclimate (meteorological screen) and 

microclimate (climate at or very near to the host surface, canopy). Microclimate affects growth and 

development of diseases to the extent to which it causes changes in the microclimate. Rain is a 

macroclimatic factor and the continuous drizzle or occurrence of dry and wet spells influence some 

diseases. Dew is a microclimatic factor and when the relative humidity increases above 70 % 

condensation begins on plants. Microclimatic factors influence plant diseases more than 

macroclimatic factors. 

Keeping in view the importance of meteorological variables, it is essential to measure them 

accurately by correct meteorological instruments. In the present lecture efforts have been made to 

explain in brief the ways and means of measurement of important meteorological weather 

variables especially in the meteorological observatory which are situated almost in all the State 

Agricultural Universities / ICAR Agricultural Research Institutes all over the country. However, the 

micrometeorological weather variables are monitored by Automatic Weather Stations which are 

being installed in the cropped fields for specific research purpose. 

A) Measurement of Macro- meteorological variables 

A brief account of method of measurement of major macrometeorological variables along with the 

instruments used in the meteorological observatory for this purpose is given below: 

A plain area of 55 m (N-W) x 36 m (E-W) size with short cut grasses provides a good 

exposure for all the meteorological instruments in the observatory. If a person stands at the gate 

facing the observatory plot, he will find the tall instruments in the back row and shorter instruments 

in the front rows. In general the instruments are separated at a distance of 9 m from each within 

rows of 12 m apart. The method of measurement of the important meteorological variables is 

described under the following sub-heads:- 

1. Maximum and Minimum Temperatures 

The maximum and minimum air temperatures ( o C) are measured by maximum and 

minimum thermometers, respectively. They are housed in a single stevension in approximate 

horizontal position at about 4 feet height from the ground. The screen is errected on 4 wooden 

posts supplied with the screen with its door opening to the north and the bottom at 4 feet 

approximately above the ground level. 

2. Relative Humidity 

The relative humidity (%) is measured indirecely by the readings of dry and wet bulb 

temperatures. The dry and wet bulb temperatures are measured by dry and wet bulb 

thermometers wich are placed in the above Stevenson screen perfectly in the vertical positions. 

The height of the bulbs of dry and wet thermometers should be from 4' 3" to 4' 6" above the 

ground, respectively for correct measurements. From the readings of dry and wet bulb 

- 90 -


temperatures the relative humidity is computed using Hygrometric Tables prepared by India 

Meteorological Department (IMD), Pune, based on the values of Atmospheric Pressure of the 

observatory locations throught the Country. At Pantnagar the Hygrometric Table of 1000 mb is 

used. 

3. Soil Temperature: 

The soil temperatures ( o C) in the observatory are measured by specially designed Soil 

Thermometers at 5, 10 and 15 cm soil depths. The plot where these thermometers are exposed 

should not receive any shadow from the neighboring instruments or objects. The bulbs should be 

at a vertical depth of 5 cm, 10 cm and 20 cm below the soil surface and the slant of the stem of the 

thermometer should be towards north, i.e. the observer should be able to read the instruments by 

sitting to the south of the instruments. 

4. Rainfall 

The rainfall is measured by Raingauge. The ordinary raingauge is errected on a masonry 

or concrete foundation of 3'x 3'x 3' size and sunk into the ground. Into this foundation the base of 

the gauge is cemented so that the rim of the raingauge is exactly one foot above the ground level 

and 10" above the concrete structure, i.e. the concret structure will project 2" above the ground 

surface. While getting the gauge, great care is taken to ensure that the rim is perfectly level. 

5. Bright Sunshine Hours 

The recording of the number of bright sunshine hours (hrs) is done by Campbell Stoke's 

type Sunshine Recorder. This instrument is exposed on the terrace of the roof or on a pillar in the 

'open' where the horizon is clearly visible between North - East and South - East on the Eastern 

side and between North - West and South - West on the Western side. The instrument is placed 

on a solid masonry pillar of any suitable height of 5' or 10' above ground depending upon the 

exposure on eastern and western sides and rigidly fixed to it after proper adjustment is made. The 

number of burns on the sunshine cards are counted to compute the duration of bright sunshine 

hours (hrs) in a day on daily basis. However, no burning on cards takes place on cloudy days. 

6. Solar Radiation 

The quantity and intensity of solar radiation is measured by Pyranometer. This instrument is 

placed in the same way as the sunshine recorder. The output in terms of solar radiation is 

expressed in W/m2 or Cal./cm2/day units. 

7. Wind Speed and Wind Direction: 

Wind speed (km/hr) is measured by Anemometer while its direction (in terms of Compass 

points) is measured by Wind vane. These wind instruments are errected at a height of 10 feet from 

the ground on wooden posts. The site for these instruments must be as open as possible and 

there must not be any object loftier than the instrument for a long distance (as far as possible) 

around. Long trees and building in the neighborhood are always objectionable. Even if there are 

not lofty enough to screen the instruments, they serve to cause eddies or swirls which act on the 

- 91 -


windvane from a direction different from that of a general air current in the neighborhood. 

Such obstructions do not also allow winds from all directions to strike the anemometer cups with 

equal force. The standard exposure of wind instruments over open level ground in the observatory 

plot should be 10 ft. above the ground. The distance between the wind instruments and any 

obstruction should be at least 10 times the height of the obstruction. 

8. Dew 

Dew (mm) is measured by Dew Gauges which are exposed at four heights on a stand and 

the appearence of dew drops is compared with the standard photographs to quantify the dew in 

terms of mm of dew fall on daily basis. 

9. Continuous Recording of weather variables: 

i). Air Temperature: 

The continuous recording of air temperature ( o C) is done by the Thermograph or 

Thermohygrograph. The recording is done on a daily or week chart depending upon the clock 

drum. They are placed in the observatory area inside the double Stevenson screen. In the same 

screen, a standard thermometer is also placed for comparison with its bulb at the level of the 

thermal element and at a horizontal distance of about 5" from it. They are also installed in the 

laboratory for recording of room temperature. 

ii). Relative Humidity: 

The continuous recording of the relative humidity (%) of free air in the observatory is done 

by Hair Hygrograph or Thermohygrograph. The recording is done on a daily or week chart 

depending upon the clock drum. They are exposed in the observatory in the same above double 

Stevenson screen. The Stevenson screen should be located in a place where the surrounding air 

is not polluted by excessive smoke or dust particles or is surcharged with brine or oil vapour, since 

these instruments have a deleterious effect upon the hygroscopic properties of the hair. They are 

also installed in the laboratory for recording of room temperature. 

iii). Rainfall 

Continuous recording of rainfall in the observatory is done by Self Recording Rain Gauge 

on Chart attached with a clock drum. The recording is done on a daily or week chart depending 

upon the clock drum. 

The standard meteorological week average distribution of major weather variables 

recorded during 2012 at Meteorological Observatory situated at Pantnagar is given in Fig.1. 

B. Measurement of Micro-meteorological variables 

The measurement of micrometeorological weather variables in the country or the World is 

done through Automatic Weather Stations (AWS). These AWS are installed in the open fields or 

within cropped fields to monitor the micro-meteorological conditions of crops. The automatic 

weather station is composed with various micro-meteorological instruments for monitoring of 

micrometeorological weather variables such as Air temperature ( o C), Relative humidity (%), Wind 

- 92 -


speed (m/s), Wind direction (degrees from North), Leaf temperature ( o C), Leaf wetness (% of 

total wet), Solar radiation (W m- 2 ), Net radiation (W m- 2 ), Rainfall (mm) and Soil temperature ( o C) 

etc. A sketch of AWS is given in Fig.2. The main and important features of the system are 

described as below: 

1. Wide range of sensors: A maximum of 20 sensors can be a attached to this at a time. 

2. Flexible data storage: It has Internal memory to store 19, 200 data points i.e. hourly data 

for continuous 40 days at a time can be stored. 

3. Versatile data transfer: Software package is available for automatic routine collection of 

data at pre determined time interval which can be modified as per the need and 

requirement. 

4. Fully protected: It has a weather proof enclosure to protect data logger and peripheral 

against dust and moisture. The logger can operate over the range from - 25 o C to + 50 o C 

without any error. 

5. Integral data processing: The processing includes the averages of maximum and minimum 

averages of all weather variables, standard deviations, wind vector integration etc. 

6. Robust construction: Tripod and mast are build from thick walled, galvanized steel tubing 

with nickel-plated fittings. The mast is 3 metre in height with adjustable cross-arm supports 

for sensors. The mast can be positioned precisely by independently adjusting tripod legs. 

Each leg is provided with a flat foot with 12 mm hole which allows anchorage to the ground 

by stake or to concrete. A lightning conductor and earth spike are also included to save the 

sensors and data logger from destructive effects of Thunderstorm and Lightning as and 

when experienced in the area. For measurement of weather parameters in and over the 

Horticultural crops, a mast of 30 meter height (existing in the nearby site in the same field) 

can be used for sitting the sensors at desired heights depending upon the height of 

horticultural crops as per the need and requirement. 

7. Minimum maintenance: Once erected, the AWS requires very little routine attention. 

8. Recording device: It has a 21 X Micrologger as recording device. It is a rugged fieldproven 

datalogger suitable for any application requiring data acquisition, on line data 

processing or electronic control. It is compact and power full battery-powered device which 

effectively combines the functions of micro-computer, clock, calibrator, scanner, frequency 

counter and controller with one smaller enclosure. The 12 volt Nickel-Cadmium battery is 

chargeable by solar panel. The micrologger is programmed to handle almost any task 

including signal averaging, excite and delay, totaling, maximum and minimum, standard 

deviation, scaling, 5th order polynomial processing, low-pass filtering and wind vector 

calculation which are fully supported by simple program statements, together with a 

histogram command for direct calculation of frequency distributions. Software support is 

available to simplify more complex programming tasks and to avoid inspection and 

- 93 -


processing of stored data. 

3. Importance of weather variables in disease management 

No doubt, that there is a close relationship between plant diseases and the weather 

variables. The viral and bacterial diseases are more weather-depended due to the fact that viral 

and bacterial pathogens remain at fixed locations, consistently exposed to a particular type of 

weather for a sufficiently long period. Some of the examples of disease-weather relationships are 

given below: 

1. High air temperatures may set limits to the development of plant disease. A high temperature of 

> 35 ( o C) is fungicidal to the organism causing blister blight in tea. A temperature of > 25 o C 

prevents spore formation in "phytophthora infestanis", the late blight fungus. Relatively high 

temperatures are important for the rate of inoculums build up of downy mildews. In potato blight, 

temperatures near the optimum for vegetative mycelial growth (19 -22 o C) stimulate the 

development of blight within the potato leaves, thus favouring spread by conidia produced by 

the leaves. 

2. Soil temperature play an important role in management of various diseases specially the soil as 

well as the seed born diseases. Heating of soil by solar radiation can be managed by using the 

mulches. Killing of fungal spores may be higher under high soil temperature conditions compared 

to low temperatures. Generally the soil temperature data is recorded during 0700 and 1400 hours 

of the day and an average value is calculated. But it did not give the clear picture of periodic soil 

temperature variations under mulch and non mulch conditions. For example the effect of soil 

solarization on soil temperature regimes showed that degree day accumulation varied from 919 

(38.3 o C) to 787 (32.8 o C) degrees under plastic mulch and non-mulch, respectively, in a single 

day at Pantnagar. 

3. Microclimatic humidity is of importance for fungal plant diseases, and not the macroclimatic 

humidity as registered in meteorological screens. Further, disease is more affected by 

microclimatic conditions in the plant canopy than by the macroclimatic ones as measured at the 

standard meteorological stations / observatory located at more distance from the crop field. 

4. The duration of leaf wetness (LWP) is important in the development of plant diseases. The 

germination and substantial crop infection by "phyphthora infestanis" requires a minimum LWP of 

13 hours. The LWP for infection by several pathogens varies from 0.5 hours to more than 100 

hours. The accomplishment of substantial infection by "Venturia inaequalis ", the fungus causing 

scab on apples and pears, require a period of wet leaves the minimum duration of which is linked 

to the temperature error. Duration of precipitation and the persistence of fog are of prime 

significance in LWP. Typically the infection process on wet leaves proceeds more quickly at high 

temperatures, so that temperature during the wetting period as well as the LWP must be 

considered. Different combinations of LWP and temperatures are important for development of 

different diseases. Often the two factors are combined to construct an index for the occurrence of 

- 94 -


a plant disease of interest. 

5. Mather (1974), reported that in United States, the bacterial wilt and leaf blight in corn is related 

to the previous inter conditions. When the sum of the average temperatures of December, January 

and February remains below 38 o C, there is no chance of wilt on corn. If the sum of the average 

temperatures is above 29.5 o C, corn blight is likely to occur. This follows that if the winters are 

mild, the bacterial wilt and leaf blight are likely to spread in an epidemic form in the coming crop 

while severe winters reduce the chances of blight. 

6. Also, in United States, the severity of blue mold of tobacco is directly correlated with climatic 

conditions viz. temperature and relative humidity during early spring. The mean temperature for 

the month of January in all the tobacco growing areas of the USA directly affects the time of 

sowing, and the severity of blue mold. If the mean temperature of January is above normal, blue 

mold will appear earlier and the disease will be severe. If temperatures are below normal, blue 

mold will appear later and the disease will be less severe. 

7. Air temperature influences the epidemic development of diseases. There is an optimum 

temperature for growth of any organism and there are limits of maximum and minimum 

temperautres (cardinal temperatures) outside which it survives but can not grow. Paria and Raj 

(1987), reported that the groundnut rust disease was favourable by Warm and Humid weather and 

spread from the lower most to the 5th leaf. 

8. Butler and Wadia (1992), reported that 70 % infection in groundnut leaves occurs within a 12 

hour wetness period at optimum temperatures (20-25 o C). The period of wetness after inoculation 

with spore suspension must be continuous. Spread of disease within crop is facilitated by wind 

movement, rain splash and insects as well. It is now well established fact that at 35 o C, the 

incubation period of groundnut rust enhanced beyond 19 days and during summer months of April 

and May when ambient temperatures range from 40-45 0 C, rust remain confined to host tissues 

without expression. They also reported that for late leaf spot disease infection is greatest if leaf 

wetness is intermittent. Further the leaf spots were most prevalent in wet areas with annual rainfall 

exceeding 500-600 mm. Also fungal infection is highly influenced by wet periods which create 

surface wetness of plants. 

9. Jensen and Boyle (1966) reported that the leaf wetness by rainfall, also causes germination of 

conidia and produces green tube for proper infection to the host. They further observed that rain 

helps spore dispersal also. 

10. Rao et. al. (1994) reported that besides rain, cool temperatures of less than 20 o C also play a 

role in the mechanisms of spore releases. Low rainfall (11 mm) with 89 % relative humidity (RH) 

could increase disease scale and RH of 86 % may aid the entry of germ tube through open 

stomata. 

So, in terms of prevailing weather conditions, the incidence of several diseases can be 

even forecast if the relationship between the weather of an area and the diseases in it can be 

- 95 -


visualised. A very simple example is given below to understand the disease - weather 

relationships: 

Let the range of climatic conditions for the development of the disease be represented by 

D, and let C 1 , C 2 and C 3 represent the climatic conditions in region 1, 2 and 3. Following three 

relationships can be established between disease and weather: 

i. In first case the range of weather conditions favouring a disease (D) is entirely the outside 

the range of weather (C 1 ) encountered in the area. Therefore, the disease can not flourish 

in that region. 

ii. In the second case the weather (C 2 ) irrespective of the prevailing weather conditions, is 

always favourable and lies within the limits (D) for the appearence of disease. In such 

cases, the weather factors are not very important for disease forecast. 

iii. In third case, which is most frequent and important one, if during the year the weather 

shifts and is no longer favourable for the disease, then the disease may not occur or 

spread at all that year. However, when weather conditions are close to or favourable for 

disease, the chances of attack from the disease will be comparatively greater. 

4. Conclusion 

If these quantification studies are continued for large period of time and data is subjected 

to modeling and a better disease forecasting system can be development for sustanable 

management of plant diseases under field conditions. 

REFERENCES 

• Butler, D.R. and Wadia, K.D.R. (1992). Groundnut foliar disease, infection and leaf wetness in 

groundnut: A global perspective. Proceedings of an International Workshop, ICRISAT, 

Hyderabad, A.P., India., Nov. 25-29, 1997, pp.475. 

• Jensen, R.F. and Boyle, L.W. (1966). The effect of temperature, relative humidity and precipitation 

on peanut leaf spot. Plant Dis. Rep., 49 : 975-978. 

• Mather, J.R. (1974). Climatology, Fundamentals and Applications. McGraw Hill Company : 181- 

214. 

• Paria, T.K. and Raj, S.K. (1987). Epidemiology of groundnut rust. Current Research, 16 : 100- 

102. 

• Rao, P.A.; Ramesh Babu; G. Sarda; Jayalakshmi Devi, R. and H. Naidu. (1994). Prediction and 

prevention of late leaf spot on kharif groundnut. Pages 386-397, In Sustainability of 

Oilseeds, edited by Prasad M.V.R., Indian Soc. Oilseeds Research, Hyderabad. 

- 96 -


- 97 -


Role of Organic Amendments in the Management of Soil Borne Plant 

Pathogens 

R.P. Singh & Bijendra Kumar 

Department of Plant Pathology, G.B.P.U.A.&T., Pantnagar- 263 145 (Uttarakhand) 

Soil borne plant pathogens survive in the soil and cause extensive damage to many crops, 

and are often difficult to control with conventional strategies such as the use of resistant host 

cultivars and synthetic fungicides. The lack of reliable chemical controls, the occurrence of 

fungicide resistance in pathogens, and the breakdown or circumvention of host resistance by 

pathogen populations (McDonald and Linde, 2002) are some of the reasons underlying efforts to 

develop new disease control measures. The ban of methyl bromide, the most effective fumigant 

used worldwide for soil disinfestation, has further increased the need for alternative control 

methods. In this context, the search for an alternative with high efficiency, low cost and limited 

environmental impact is the immediate need for eco-sustainable modern agriculture. In the past 

century, the introduction of synthetic inorganic fertilizers, disease-resistant varieties and fungicides 

has allowed farmers to break the link between organic amendments and soil fertility. As a result, 

organic materials such as crop residues and manure from essential resources became solid 

wastes. After the reduction of the organic input, soil organic matter decreased over time, soil 

fertility declined, and a large number of diseases caused by soil borne plant pathogens spread in 

agro-ecosystems. However, a renewed interest in application of organic matter (OM) to soil, for 

control of soil borne pathogens, has been stimulated by public concern about the adverse effects 

of soil fumigants and fungicides on the environment, and the need for healthier agricultural 

products. Several studies have shown that organic amendments such as animal manure, green 

manure, incorporation of crop residues into the soil, composts and peats can be very effective to 

improve soil structure, fertility and in controlling soil borne plant pathogens such as Fusarium spp., 

Phytophthora spp., Pythium spp., Rhizoctonia solani, Sclerotinia spp., Sclerotium spp., 

Thielaviopsis basicola, Verticillium dahliae, Meloidogyne spp. Ralstonia solanacearum etc. 

Different complementary mechanisms have been proposed to explain the suppressive 

capacity of organic amendments: 

 

 

 

 

 

 

Enhanced activities of antagonistic microbes 

Increased competition against pathogens for resources that cause fungistasis 

Release of fungitoxic compounds during organic matter decomposition 

Induction of systemic resistance in the host plants 

Changes in soil physio-chemical properties that are unsuitable for pathogens 

Combinations of these mechanisms 

However, despite the potential value of organic soil amendment, there are several 

concerns about its efficacy and potential side-effects that limit practical applications. For instance, 

some reports indicate that the effectiveness of OM amendment is variable and, in some cases, 

- 98 -


can enhance disease severity. These negative effects of OM amendment were often associated 

either with increased inoculum of pathogenic fungi because OM provides the substrate for their 

saprophytic growth or with release of phytotoxic compounds that may damage plant roots and 

predispose them to pathogen attack. The inconsistent disease control results obtained with OM 

amendments, with both suppressive (disease reduction) and conducive (disease increase) effects, 

produced skepticism in farmers about the use of these materials. In addition, despite extensive 

research, no reliable methods are currently available to predict the effect of different OM 

amendments on soil borne pathogens (Bananomi et al., 2007). 

Effect of Different Types of Organic Amendment: 

The ability of different OM types to reduce pathogen populations is highest for organic 

waste, intermediate for crop residues and lowest for composts. However, it is interesting to notice 

that crop residues increased pathogen populations in some cases. For crop residues, a key factor 

that affects the fate of pathogen populations is oxygen availability in amended soil. In aerobic 

conditions the effect of amendment on fungal populations is very variable. In fact, this includes N 

rich tissue with a low C/N ratio, cruciferous species rich in glucosinolates that are known for their 

antifungal activity after hydrolysis to isothiocyanates, and N-poor residues with high C/N ratio 

(grasses, straw, wood chips, etc.). 

Effect of Organic Amendments on Disease Suppression 

Suppressive capacity varied dramatically among different OM types. Composts and 

organic wastes are the most suppressive and only in a few cases did these materials increase 

disease incidence. The effect of amendment with crop residues is more variable, and although 

they are often suppressive, they could also be conducive. The suppressive capacity of the 

amendment varied largely towards different pathogens. 

OM amendments have multiple direct and indirect effects on the plant pathogen- beneficial 

microbe system. Understanding the relative importance of these effects is important for 

management of crop residues and organic wastes. For these materials, the balance between 

negative effects (i.e. phytotoxicity and food base for pathogens) and positive effects (i.e. fungitoxic 

and fungistatic effects and resistance induction) is pivotal to avoid disease increase. Promising 

results have been obtained with T. basicola and V. dahliae. Strong evidence indicates that the 

temporary accumulation of ammonia or nitrous acid (in acidic soils), following the application of 

crop residues or wastes with high N contents (C/N ratio below 10), are responsible for the 

eradication of Verticillium microsclerotia. Unfortunately, these effects are very variable among 

different soil types, being more effective in sandy, OM-poor soils. Detailed and quantitative 

knowledge of the pathways of the N cycle (ammonification, nitrification, denitrification, etc.) in 

different soils is necessary, for effective disease control and to avoid environmental pollution if 

large quantities are applied. Positive results have also been achieved by using OM with high C/N 

ratios. These materials can stimulate microbial activity, which can in turn deplete N availability, 

- 99 -


and, consequently, impair the pathogen infection process. However, N starvation immediately after 

OM application can also impair plant growth. To avoid OM phytotoxic effects, correct management 

of crop residues and wastes is a basic step. This can be achieved by optimizing application rate 

and the timing between OM applications and planting the crop. Unfortunately, it is impossible to 

generalize about how long planting should be delayed. If decomposition occurs anaerobically, OM 

generates adverse conditions for many phytopathogenic fungi, but unfortunately, also for plant 

growth. This emphasize the importance of studying both plant and pathogen responses to OM 

during decomposition. Special attention should be paid to choosing the application rate. Finally, 

application of crop residues, and to a lesser extent of undecomposed organic wastes, should be 

avoided if the phytopathological problems are due to Pythium spp. or R. solani. These pathogens 

often respond positively to OMs and colonize them as nutrient substrates. Sclerotium spp. is 

another good example of such a pathogen, favoured by the presence of crop residues. Volatile 

compounds emanating from such residues can stimulate germination of sclerotia with a 

consequent overall increase of disease incidence and severity (Punja and Grogan, 1981). 

Organic Matter and Phytotoxicity 

OM phytotoxicity has often been considered an idiosyncratic phenomenon and 

consequently, an unpredictable side-effect of OM amendments. The occurrence and intensity of 

phytotoxicity are measurable and predictable depending on the environmental conditions where 

decomposition occurs. Phytotoxicity largely varied among different OM types, according to the 

following rank: crop residues >organic wastes > composts > peats. As decomposition proceeds, 

phytotoxicity consistently declines. Many ecological studies report the phytotoxic effects of 

decaying plant materials. However, during decomposition, both the abundance and the activity of 

phytotoxic compounds continuously change over time because of their sorption and polymerisation 

on soil organic matter and clay minerals, and because of chemical transformation by 

microorganisms. Bonanomi et al. (2006) showed not only a widespread presence of phytotoxicity 

in decaying plant litter, but also predictable dynamics in relation to both decomposition duration 

and environmental conditions. 

Conclusion 

There is an urgent requirement to find sustainable strategies for the control of soil borne 

diseases, for both conventional and low-input farming systems. In the last 70 years a massive 

number of studies have been carried out on the subject of OM amendments for the control of plant 

diseases, and this technique appears to be one of the most promising for its low cost and the 

limited environmental impact compared to fungicides and fumigants. OM amendments have great 

potential but give inconsistent control and sometimes increased disease severity and phytotoxicity, 

which still limit their use. There is no doubt that the benefits of OM amendments far outweigh their 

drawbacks but while the impact of this technique on pathogen populations and disease 

suppression remains unpredictable. Significant progress has been made towards understanding 

- 100 -


the biology of disease suppression by OM amendments in specific plant-pathogen systems, such 

as peat-Pythium, leaf compost-Pythium, N-rich waste-V. dahliae, compost-F. oxysporum f.sp. 

lycopersici (Borrero et al., 2004) etc. However, still lacking are reliable guidelines to predict the 

impact of any type of OM amendment on specific soil borne diseases. Researches on the following 

areas may be valuable for better understanding of the subject: 

How different OM types modulate plant-pathogen-antagonist relationships; 

Developing OM amendments able to enhance the activity of beneficial microbes, without 

stimulating pathogen populations; 

Improving the effectiveness of combined applications of OM amendments and biological 

control agents; 

Identifying parameters that consistently predict the suppressive ability of different OMs. 

REFERENCE 

• Borrero C., Trillas M.I., Ordovás J., Tello J.C., Avilés M.,2004. Predictive factors for the 

suppression of Fusarium wilt of tomato in plant growth media. Phytopathology 94: 

1094-1101. 

• Bonanomi G., Sicurezza M.G., Caporaso S., Assunta E., Mazzoleni S., 2006. Phytotoxicity 

dynamics of decaying plant materials. New Phytologist 169: 571-578. 

• Bonanomi, G., Antignani, V., Pane , C. and Scala F., 2007, Suppression of soilborne fungal 

diseases With organic amendments J. of Pl. Pathol., 89(33):11-324 

• McDonald B.A., Linde C., 2002. Pathogen population genetics, evolutionary potential, and durable 

resistance. Annual Review of Phytopathology 40: 349-379. 

• Punja Z.K., Grogan R.G., 1981. Mycelial growth and infection without a food base by eruptively 

germinating sclerotia of Sclerotium rolfsii. Phytopathology 71: 1099-1003 

- 101 -


Evaluation and Selection of Promising Trichoderma Isolates for the 

Management of Soil Borne Fungal Plant Pathogens 

A.K. Tewari 

Department of Plant Pathology, GBPUA&T, Pantnagar- 263 145 (Uttarakhand) 

Dual culture Method: This method is used for testing mycoparasitic activity of antagonist. Pour 

15-20ml sterile PDA in sterile plates amended with Chloromphenicol (100 mg/lit.) or streptomycin 

(100mg/lit). Place the bits (5mm) of the test pathogen as well as antagonist on the PDA plates 

opposite to each other from 1.0 cm from the periphery of plates (if both are fast growing) or place it 

2-3cm apart (if both are slow growing). Incubate the plates at 25+1 0 C for desired duration. 

Observe the plates regularly. 

I. In-vitro evaluation and selection 

(A). Mycoparasitism: 

In mycoparasitism the pathogen stops growing upon contact with the antagonist and its 

mycelium begin to lyse backwards and the antagonist continue to grow over the test fungal 

pathogen. 

Observations 

 

First observation should be taken just after contact and measure the growth of the 

pathogen in dual culture. 

After contact, observations should be taken regularly at 3 day interval until the antagonist 

completely parasitizes the test pathogen or antagonist stops growing over the test pathogen. 

Calculate the percent inhibition (parasitized growth) of the test pathogen by comparing the growth 

of the pathogen (after parasitization) with its initial growth (just after contact). To see the hyphal 

interaction small bits of mycelium can be taken from interaction zone and observe under 

microscope. 

Mycoparasitism of Sclerotial plant pathogens 

Collect freshly non-dried sclerotia , surface disinfested and wash in sterile distilled water. 

Immerse these sclerotia in an aqueous spore or mycelial suspension of the antagonist for 1-5 min. 

Place these sclerotia in culture plates containing sterile moist sand. Incubate it for 1-4 week at 25- 

28 0 C. After desired period of time observe colonization of antagonist on decayed sclerotia 

B). Antibiosis: 

The antagonists that has antibiosis effect (formation of zone of inhibition) in dual culture 

must be further tested using cellophane membrane and cell free culture filtrates 

Non Volatile compounds: 

1. Cellophane membrane method 

Place sterilized disk (90mm) of a cellophane membrane on culture medium. An agar disk of 

antagonistic fungus is placed at the centre of the cellophane membrane. 3-4 days after incubation, 

remove the cellophane membrane along with the growth of antagonist. An agar disk from culture 

- 102 -


of actively growing test pathogen is transfer to the position previously occupied by the antagonist. 

Test pathogen grown on PDA plates serves as check. The radial growth of the test pathogen is 

recorded 3-4 days after incubation and compare with check. The reduction in radial growth of the 

test pathogen shows production of non-volatile compounds by the antagonist. 

2. Cell free culture filtrate 

The antagonist is grown on potato broth medium either in stationary or in shake culture. 

After sufficient mycelium growth the mycelium and other cells are removed by filtration through 

filter paper and then sterilized by passing through G 1 ,G 3 and G 5 sintered glass filter. The cell free 

sterile culture filtrate is tested for efficacy of antagonist against the fungal pathogens by following 

ways. 

a. Assay in solid medium 

i. Food Poison technique 

ii. Filter paper disc method 

iii. Agar well method 

b. Assay in liquid medium 

c. Spore germination test 

a. Assay in solid medium 

i. Food Poison technique 

Mix sterile cell free culture filtrate in sterilized PDA flasks (various concentrations) 

and pour in Petri dishes. Inoculate the test pathogen at the centre of the PDA plates. Pathogen 

on PDA plates without culture filtrate serves as control. Incubate at 25+1 0 C for desired 

duration. Per cent inhibition was calculated by measuring the radial growth of the test fungus in 

amended medium and compare with check. 

ii. Filter paper disc method 

Pour 15ml of a PDA in sterile Petri plates. After solidification uniformly spread 4ml of 1.5% 

water agar, seeded with 10 4 spores/ml of the test pathogen. 4-6 filter paper dics (1-2 cm dia, 

autoclaved and dried) soaked in culture filtrate and dried, are place on the seeded agar medium 

from 1-1.5cm periphery of the plates. After incubation measure the zones of inhibition around the 

filter paper . 

iii. Agar-well Method 

Prepare PDA plates as above. Remove Agar plugs at a distance of 1-2 cm from the 

periphery of the PDA plate with the help of cork borer of 1-2 cm dia. Fill the wells with a known 

concentration and standard quantity of the cell free culture filtrate. After incubation, measure the 

zones of inhibition around the wells. 

b. Assay in liquid medium 

Add sterile culture filtrate at desired concentration in a known volume of potato broth and 

mix well. The flasks containing medium is inoculated with a 5 mm discs (2 no.) of the test 

- 103 -


pathogen. Incubate until sufficient growth has occurred in check (medium without culture filtrate) 

flask. Measure fresh and dry weight of the test pathogen growth and calculate per cent inhibition 

c. Spore germination test 

Place 0.2-0.5ml of the desired concentration of the cell free culture filtrate in the wells of a 

cavity slide and dry at room temp. The same amount (0.2-0.5ml) of spore suspension of the test 

pathogen (5X10 3 spores/ml) is added over the dried culture filtrate and mix well with help of a 

glass rod. Incubate it in a humid chamber at 25-28 0 C. Spore germination and characteristics of the 

germ tube is recorded at 12 hr interval and compare with check (cavity slides without culture 

filtrate) and calculate per cent inhibition. 

Volatile compounds: 

Grow antagonist on PDA plates. 3-4 days after incubation, inoculate the test pathogen in 

separate PDA plates. Place inoculated test pathogen (upper) on the 3-4 days old antagonistic 

plates (lower) by removing lids of both the plates. Make pair by binding both the plates opposite to 

each other with parafilm. Incubate the paired plates until full growth has occurred in check plates 

(inoculated with test pathogen alone). Calculate the per cent growth inhibition by measuring the 

growth of the test pathogen and comparing it with check plates. The reduction in radial growth of 

the test pathogen shows production of volatile compounds. 

C. Compatibility of fungal antagonist with commonly used chemicals: 

‘Food Poison Technique’ is used to test the compatibility of fungal antagonist fungicides, 

insecticides, herbicides and other chemicals to be commonly used for plant health. 

II. Evaluation and selection of promising Trichoderma isolates in glasshouse 

1. Disease Management 

A. Seed treatment 

B. Seedling dip treatment 

C. Soil application 

D. Soil drenching 

Observations 

i. Disease incidence / Disease severity 

ii. Population dynamics (CFU /g soil at 7 days interval) 

2. Systemic induced resistance 

A. Seed treatment 

B. Seedling dip treatment 

C. pre-spraying 

Observations: 

a. Peroxidase, 

b. Phenyl alanine ammmonia lyase 

c. Polyphenol oxidase 

- 104 -


d. H 2 O 2 content 

e. Phenol content 

f. Superoxide dismutase 

g. Lypoxygenase 

h. Chlorophyll content 

i. Membrane stability index 

3. Plant growth promoter 

Observations: 

a. Biomass of plant 

b. Root length & weight 

c. Shoot length & weigh 

III. Qualitative parameters for formulation 

a. Spore concentration 

b. Shelf life (Viability) 

c. Food for initial establishment 

IV. Field Testing 

V. Maintenance of culture 

Selection of promising Trichoderma isolates for commercialization 

i. Select broad spectrum isolate. 

ii. Evaluate performance under the range of environmental conditions. 

iii. Evaluate formulations. 

iv. Evaluate application methods. 

- 105 -


Biodeterioration of Seed in Storage and its Control by Microbial 

Antagonists 

K.Vishunavat 

Department of Plant Pathology, G.B.P.U.A.&T., Pantnagar- 263 145 (Uttarakhand 

As a result of public concerns about the safety of our environment and food supply, it has 

become a national research priority to develop new pest management technologies that reduce 

our use of chemical pesticides. Microorganisms naturally present in agricultural ecosystems are 

being studied as environmentally compatible alternatives to traditional chemical methods for 

controlling plant diseases. A serious impediment to bringing many such microorganisms 

discovered by ARS scientists to the marketplace is the lack of knowledge of cultivation and 

formulation technologies needed to produce cells that are tolerant to the stresses of large-scale 

cultivation, separation, processing (drying or dewatering biomass), and storage. There is need to 

focus upon the studies to discover the genetic and metabolic mechanisms that enhance microbial 

stress tolerance such that high yields of viable effective cells with long shelf lives can be produced. 

Post harvest and storage diseases in seed crops 

Worldwide, diseases of crop plants cause losses estimated to be 12%, and post harvest 

losses due to food spoilage have been estimated to be between 10% to 50%. In the United 

States, these figures are estimated to be 12% and 9%, respectively. Finding ways to prevent 

microorganisms from causing these losses would help ensure a stable food supply for the world's 

ever expanding population. 

Post Harvest Storage of Grain 

a. An international Association, he group for Assistance on systems relating to grain after 

harvest (GASGA) , is a voluntary association linked with donor operations that promote the 

preservation of grain in storage . 

b. GASGA has following objectives 

c. To stimulate technical cooperation in all aspects of grain post harvest research and 

development in both developing and developed countries 

d. To identify and seek ways of meeting research and development training ,and information 

needs in the post harvest subsector 

e. To serve an advisory role and provide a forum for exchange of technical information 

,experience and ideas for a global collaborative approach to fungal and mycotoxin 

problems 

Storage fungi 

Storage fungi (also called storage molds) are usually not present to any serious extent 

before harvest and invade grains or seeds during storage. Small quantities of spores of storage 

fungi may be present on grain going into storage or may be present on spoiled grain present in 

harvest, handling and storage equipment or structures. Under improper storage conditions this 

- 106 -


small amount of inoculum can increase rapidly leading to significant problems.The most common 

storage fungi are species of Aspergillus and Penicillium. These fungi are widely distributed and 

almost always present. Other than certain fungi of Cladosporium herbarum and Botryodiplodia 

sp.also cause deterioration during storage. Storage fungi may cause damages to the seeds during 

harvesting processing, cleaning and drying of the grains before storage and during storage 

Invasion by storage fungi 

The storage fungi get access to the seed/grain tissues via micropyle, peduncle, 

microscopic creaks on seed surface superficially over the surface of various seed tissues such as 

rachis, ,spikelets, pericarp,caryopsis.Invasion of storage fungi may follow the path into the various 

seed tissues. The fungus A.flavus colonizes the ear tip to the base of silks then glumes by the milk 

stage . However, the fungus only colonizes the seed surface and rarely penetrate cob pith. A 

flavus penetrate the maize seeds through the pericarp. There the seeds (embryo and cotyledons) 

serve as food source of the fungus. A.flavus in maize gets a way into seed through rachilla of 

adjuscent spikelet from the rachis and tracts then reaches to the floral axis through the 

parenchyma of the rachilla and reaches to the innermost layer of the pericarp.The hyphae in that 

case may be inter or intracellular in floral axis or and inside the seed orInvasion of maize seed by 

Aspergillus flavus may also takes place via the silks. 

Factors affecting storage fungi to develop in storage 

• The development of storage fungi in stored grain is influenced by 

• The moisture content of the stored grain, 

• The temperature of the stored grain, 

• The condition of the grain going into storage, 

• The length of time the grain is stored and 

• The amount of insect and mite activity in the grain 

Table 1: Correlation of Fungal Species and Storage Insects 

Insect screened 

Fungi isolated 

Sitophilus oryzae L. A flavus, A. candidus, A. ochroaceus, A. 

fumigatus,A. terreus, A. parasiticus, A. 

restrictus, A. terricola,A. ustus, A. versicolor, A. 

sydowi, A. ruber, A. chevalier),A niger, P. 

rugulosum, Amblyosporium sp., Cladosporium 

sp., 

Tribolium castaneum Herbst A. flavus, A. candidus, P. islandicum, A. 

versicolor, A. niger,A. ruber, A. chevalier 

Trogoderma granaria Everts A. flavus, A. candidus, P. islandicum, A. ruber, 

A. glaucis gr.,A. niger, A. sydowi, A. versicolor, 

P. restrictum 

Bruchus chinensis Linn A. flavus, A. candidus, A. sydowi, A. ruber, A. 

glaucus gr. 

Oryzaephilus surinamensis Linn A. flavus, A. ochroaceus, A. restrictus, A. 

glaucus gr.,A. terreus, P. decumbens, 

Cladosporium sp. 

- 107 -


Stegoblum peneceum Linn 

Rhizoperth dominica Fab 

Araecerus fasciculatus 

Corcyra cephalonica Staint 

Esphestia cautella Walker 

A. candidus, A. glaucus gr. 

A. candidus, A. ochraceus, A. niger. A. glaucus 

gr. 

A. flavus, A. candidus, A. niger, A. glaucus gr. 

A. flavus, A. candidus, A. ochraceus, A. sydowi, 

A. ruber,A. niger, A. restrictus, A. versicolor, P. 

spinullosum,P. corylophilum, Nigrospora sp. 

A.flavus, A. candidus, A. niger, A. glaucus gr.,A. 

terreus, A. ruber, A. versicolor 

Factors affecting damages in storage 

• Moisture content 

• Temperature 

• Cracked and broken kernels and foreign material 

• The extent to which grain in already invaded by storage fungi 

• Length of time the grain is to be stored. 

• Amount of insect and mite activity in grain 

Losses due to storage fungi in storage 

• Seed discolouration 

• Hot spots and Heating in storage 

• Respiration 

• Biochemical changes. 

• Loss in dry weight 

• mycotoxin production 

1. Seed discolouration 

Appearance is an important factor in grain grading, i.e. the grain's commercial 

quality.Seeds become distinctly discoloured during storage as a result of heating caused by 

internal fermentation. The most common storage fungi are species of Aspergillus and 

Penicillium.some of the seeds discolouration. Moulds growing on stored grain affect its 

appearance: dulling the kernel's normally bright appearance, discolouring the kernels, and 

producing white threadlike-mycelia on the kernels.For example, in corn ,Penicillium rot caused by 

Penicillium species is evident as discrete tufts or clumps or a blue-green or gray-green mold 

erupting through the pericarp of individual kernels or on broken kernels .Aspergillus flavus is 

evident as a greenish-yellow to mustard yellow, felt-like mold growth on or between kernels, 

especially adjacent to or in insect damaged kernels. 

2. Hot spots and heating in storage 

Stored grain insects and fungi commonly act together to destroy grains and feeds. Mould 

can cause kernels to clump together and obstruct the free flow of the grain during handling. The 

moisture and heat from their metabolic activity (respiration) will increase grain moisture and 

temperature which may lead to self-ignition. 

- 108 -


The moisture and warm temperatures of spoiling grain pockets will attract stored product 

pests such as rusty grain beetles and mites. If the hot spot develops in the fall, it may stay warm 

enough for the insects to over winter. 

Hot spots may occur when a pocket of grain is wetter than the rest of the stored grain due 

to improper storage. Mould can begin to grow in a pocket of moist grain or oilseeds and produce 

more heat and moisture. The resulting increase in temperature and moisture contents causes an 

increase in the growth and respiration of the moulds. 

3. Respiration 

During respiration the carbohydrates, C6 H12 O6, which make up most of the dry matter in 

the seed, are dissolved by enzymes and are consumed by moulds. This loss in dry matter causes 

a reduction in the marketable mass of grain. Respiration is of two types: 

Anaerobic 

For aerobic respiration to continue, oxygen must continue to diffuse into the bulk. If the 

storage container is air tight and oxygen is flushed out or not replenished as it is consumed then 

anaerobic processes may take over. 

Anaerobic 

Anaerobic processes can be desirable, such as in the fermentation of silage, but for most 

stored products anaerobic activity causes unacceptable odours, tastes, and other changes in the 

product. 

The actual rate of heat production can vary considerably. If lipids are oxidized the amount 

of heat released is 3946 kJ/g as compared with 15.7 kJ/g for glucose (Multon 1988). If oxygen is 

absent and fermentation of glucose occurs, the heat released is about one-tenth of that released 

under aerobic conditions. 

4. Biochemical changes 

Invasion of fungi on grain or seeds bring about physical and biochemical changes. For 

example, in raddish seeds infected with Aspergillus flavus changes in amount of fatty acids, 

glycerol ,sugar and amino-acids were observed. Seed borne fungi in vegetables (Brassicaceae) 

brought about the reduction in chlorophyll, starch, total sugars and amino acids besides affecting 

enzymes. Wheat grains infected with fungi also have poor flour quality. The wheat grains infected 

with (Alternaria tenuis) black point have higher protein content and reduced potassium, calcium , 

zinc and manganese in such grains. In food grains, during improper storage, are subject to mould 

attack and this is accelerated by insects under high moisture and temperature. Breakdown of fats 

causes an increase in free fatty acids, and oxidation brings on rancid flavours.In stored rice 

Aspergillus flavus and A. versicolour caused maximum reduction in carbohydrate contents.A. niger 

cause maximum reduction in oleic and linoleic acid in peanut seeds. (Vaidya and Dharma vir 

1989). The oil, from infected kernels, acrid smelling. Aspergillus flavus, Cladosporium herbarum 

and Botryodiplodia sp.caused loss in oil content in groundnut seeds 

- 109 -


5. Loss in dry weight 

This respiration results in some loss of dry weight and produces the phenomenon called 

"spontaneous heating". In cereal grains loss in quality and quantity during storage is caused by 

fungi, insects, rodents and mites. Respiration may, in certain cases, contribute to a loss of dry 

matter during grain storage. However, the losses due to respiration are minor compared to those 

caused by living organisms. 

The weight loss generally adopted as a criterion of grain damage does not give a picture of actual 

loss, as the grains containing internal infestations are not detected in such analyses. Basic 

research is needed to find the relationship between weight loss and true loss in quality brought 

about by mould or by internal infestations with the insects. 

6. Catastrophic losses due to mycotoxin production in stored grains and feed 

Mould fungi when grow on stored grain in silos or in storage bins may lead to catastrophic 

losses as they produce their secondary metabolites on stored grains which on consumption are 

health hazardous to man and animal. In the Midwest, in 1934 more than 5,000 horses died 

because of "moldy corn disease” on consumption of moldy grain. 

An outbreak of "Turkey X disease" in Great Britain in 1960 was traced to contaminated 

peanut meal from Brazil. Aflatoxin was indicated as the cause of the death for more than 100,000 

young turkeys and some 20,000 ducklings, pheasants, and partridge poults. 

In 1972, Gibberella ear rot caused extensive feed-refusal problems in swine in the Corn 

Belt. Aflatoxin has caused problems in several animal species in the southeastern United States 

for many years, and fescue toxicosis due to a fungus, Acremonium coenophialum has been a 

common problem with fescue pastures in the South for many years. 

Human suffering from mycotoxicoses includes ergot poisoning associated with ingestion of 

rye flour contaminated with ergot (holy fire, St. Anthony's fire); cardiac beriberi associated with 

Penicillium molds in rice (yellow rice toxins); and alimentary toxic aleukia (ATA,) associated with 

Fusarium molds on overwintered wheat, millet, and barley. Several mycotoxins have been linked 

to increased incidence of cancer in human beings. These include aflatoxin, sterigmatocystin 

zearalenone, patulin, ochratoxin, and fumonisin. Although the adverse effects of feeding moldy 

feeds was long known by livestock and poultry producers, a specific mycotoxin was not 

implicated.An outbreak of aflatoxicosis in India was linked to moldy corn containing aflatoxin, killing 

more than 100 persons and affecting more than 400 dogs. 

Mycotoxins have been found in four samples of seeds from 12 samples studied. In two of them, 

the toxin level exceeded the allowable concentration: Aflatoxin B-I - 15 mg/kg, and Zearalenon - 

2,000 mkg/kg. Similarly, in three of five Soya samples imported from Spain, Aflatoxin B-1 20, 30 

mkg/kg was found, respectively, while in one, sterigmatosistin 150 mkg/kg was discovered ( 2004 

Seed trade Pakistan) . 

- 110 -


7. Production of Mycotoxins 

Groundnut is one of the crops, which is vulnerable to attack of Aflatoxin. Aflatoxin may 

grow on Groundnut kernels, if the moisture content is above 8 to 9 percent. Aflatoxin often grows 

in ships cargo during transit of more than 4 to 6 weeks. Aflatoxin contamination of Groundnut is a 

major health hazard to human and animals and it is one of the most important constraints in 

Groundnut trade. The main reason for the contamination in Groundnut is due to poor pre-harvest 

and post-harvest practices like moisture stressed crop, stacking the pods/kernels in high humid 

conditions, which leads to growth of the fungus. In the international Groundnut trade, tolerance 

levels are specific for this quality parameter, with strict condition posed for Groundnut meant for 

human consumption (4 ppb in Europe). 

Management of microorganisms during post harvest operations 

• Better crop husbandry practices 

• Preharvest control of diseases and pests in field 

• Appropriate harvest procedures 

• Drying the grains 

• Building of better storage facilities and control of storage atmosphere 

• Ensiling 

• Use of microbial antagonists 

• Use of Pesticides and fungicides rodenticides 

• Sanitation of stores before storage: 

• Use of grain protectants 

• Grain preservatives 

• Fumigation 

Ensiling a process in which microorganisms in storage are managed through promoting 

the other microorganisms in such away that they may kill or stop the growth of the microorganisms 

that cause spoilage.To prevent micro-organic growth, grain must be handled like silage, 

which means promoting the growth of acid-producing bacteria in the absence of oxygen. A state of 

preservation results when the acids, produced without oxygen, kill the other microorganisms in 

such away that they may kill or stop the growth of the micro-organisms that cause spoilage. 

Combined rolling and packing result in the rapid exclusion of oxygen, which creates a favorable 

environment for acid forming micro-organisms. 

Microbial Antagonists 

Microbial Antagonists for storage microorganisms are not yet well understood. However, 

the researches that has been done has yielded exciting and promising results, and the study of 

microbial antagonists has become a rapidly expanding field in plant pathology. 

As a result of public concerns about the safety of our environment and food supply, it has 

become a national research priority to develop new pest management technologies that reduce 

- 111 -


our use of chemical pesticides and microbial antagonists is an alternative. 

Microorganisms naturally present in agricultural ecosystems are being studied as 

environmentally compatible alternatives to traditional chemical methods for controlling plant 

diseases. A serious impediment to bringing many such microorganisms discovered by ARS 

scientists to the marketplace is the lack of knowledge of cultivation and formulation technologies 

needed to produce cells that are tolerant to the stresses of large-scale cultivation, separation, 

processing (drying or dewatering biomass), and storage. There is need to focus upon the studies 

to discover the genetic and metabolic mechanisms that enhance microbial stress tolerance such 

that high yields of viable effective cells with long shelf lives can be produced.To be most effective, 

antagonists of plant disease and food spoilage should be: 

‣ genetically stable 

‣ effective at low concentrations 

‣ easy to culture and amenable to growth on an inexpensive medium 

‣ effective against a wide range of pathogens in a variety of systems 

‣ prepared in an easily distributable form 

‣ non-toxic to humans 

‣ resistant to pesticides 

‣ compatible with other treatments (physical and chemical) 

‣ non-pathogenic against the host plant 

These antagonists have been applied to the above-ground parts of plants, to the soil (and 

roots), and to plant seeds. The above-ground environment is the least stable for antagonists 

because of the extreme variability in moisture and nutrients. Soil is more stable environment for 

microbiota, but soil in most fields is generally nutrient poor, pH may range from 4-8, and 

temperatures and moisture may vary widely. In contrast, greenhouse planting mixes can be 

managed more effectively to promote antagonist colonization. Finally, it is practical to treat seeds 

to favour microbial antagonists. 

a. Biological seed treatments 

Biological seed treatments control seed pests by parasitizing the pest organisms, 

competing for food on the root system, or producing toxic compounds that inhibit pathogen growth. 

Control of surface pathogens include beneficial microbes in compost teas, herbal sprays, 

washes or oils, hot water, heat, and disinfectants. 

1. Microbial seed treatment 

2. Biodynamic Treatments 

3. Herbal Treatments 

4. Hot Water Bath 

5. Disinfectants 

Knowledge of the interactions among microorganisms and ways to manipulate microbiota 

- 112 -


is growing as research in this field rapidly expands. Antagonists have been successfully used to 

suppress tomato mosaic, foot and butt rot of conifers, citrus tristeza disease, and crown gall of 

several crops. 

Seeds have been coated with antagonists that reduce infection by pathogens and also 

enhance plant growth. The most commonly applied antagonists to the seeds are Bacillus subtilis, 

Chateomium sp.Penicillium oxalicum and Trichoderma species. Biopriming of infected carrot seed 

with an Antagonist, Clonostachys rosea, has been selected for Control of Seedborne Alternaria 

spp. 

Biological fungicides are a relatively new tool available. Biological fungicides contain beneficial 

bacteria or fungi (microbial antagonists) which help suppress pathogens that cause plant disease. 

For example, F-Stop, registered as a seed treatment for tomatoes, contains a biocontrol agent 

called Trichoderma viride sensu. T-22G Biological Plant Protectant Granules, registered as an 

in-furrow soil treatment on tomatoes and other vegetables, contains Trichoderma harzianum, 

strain KRL-AG2. 

Commercial formulations of microbial agents for treatment 

Kodiak concentrate registered for seed and pod vegetables, soybeans, wheat and barley, 

and corn plus all other agricultural seeds, contains Bacillus subtilis bacteria which colonize the 

developing root system, suppressing disease organisms such as Fusarium, Rhizoctonia, Alternaria 

and Aspergillus that attack root systems. 

When used with a chemical seed treatment, the combination of chemicals and Kodiak 

provides protection to the root for a much longer time than with chemicals alone. 

As the root system develops, the bacteria grow with the roots extending the protection 

throughout the growing season. As a result of this biological protection, a vigorous root system is 

established by the plant, which often results in more uniform stands and greater yields 

Bio-Seed-Gard is an OMRI-approved blend of micro-organisms for use as a seed 

treatment for Corn, Soybeans, Peas, Legumes, and other crops. AgriEnergy Resources, the Co. 

that developed the product, has done greenhouse and field trials showing improved: seeding vigor, 

stand establishment, root growth, plant growth, and yield. Dry blend of Trichoderma & Mycorrhizal 

species. 

CB-QGG is a liquid biological seed treatment and root growth promoter formulated with 

beneficial microbes, macro and micro nutrients, amino acids, organic acids, root growth stimulants, 

enzymes, proteins, vitamins and minerals. CB-QGG makes less available forms of soil phosphate 

available to plants, promotes nitrogen fixation, root development and quick emergence, stimulates 

cell division and increases stress tolerance. In addition, CB-QGG it produces substances which 

increase the vigor of treated plants helping them resist damage by pathogenic fungi and damping 

off. This results in a more consistent plant stand and increased yields. CB-QGG promotes early 

root growth and larger roots. Larger roots provide better access to moisture and nutrients which 

- 113 -


translates into improved health throughout the life cycle of the crop. 

b. Biodynamic (Seed Soaks and Sprays) 

Biodynamic preparations are used to enhance the biological activity of the soil. The 

preparations consist of mineral, plant, or animal manure extracts, usually fermented and applied in 

small proportions to compost, manures, the soil, or directly onto plants, after dilution and stirring 

procedures called dynamizations. The preparations are used a seed soak to encourage 

germination and growth of seedlings and for anti-fungal control. The solutions are lightly sprayed 

on seeds and then quick dried on a screen. 

Methods for Preparations 

They are numbered 500 to 508. BD#500 is made from cow manure fermented in a bovine 

horn and buried for six months through autumn and winter. It is used as a soil spray to stimulate 

root growth and the production of humus. 

BD#501 is the horn silica preparation made from powdered quartz packed into a cow horn 

and buried in the soil through spring and summer for six months. It is used as a plant spray for the 

stimulation and regulation of growth. 

BD#502 - 507 are compost inoculates and are inserted into the compost piles to increase 

microbial activity, enhancing the decomposition process. 

They are made from the fermented herbs yarrow (Achillea millefolium), chamomile 

(Anthemis nobilis), stinging nettle(Urtica dioica), oak bark (Quercus alba), dandelion (Taraxacum 

officinale), and valerian (Valariana officinalis), respectively. Each preparation stimulates processes 

essential for plant growth and are used to strengthen the life forces on the farm. 

Natural Products 

Considerable research activity has occurred in the Asian-Pacific region on the potential for 

plant extracts to control seed-borne fungi. The oils of cassia and clove inhibited growth of 

established seed borne infections of Aspergillus flavus, Curvularia pallescens and Chaetomium 

indicum in maize (Chatterjee 1990). 

Aqueous extracts of Strychnos nux-vomica, garlic bulbs, ginger rhizomes, basil leaves, and 

fruits of Azadirachta indiica were used to control Alternaria padwickii in rice seeds (Shetty et al 

1989), while extracts from peppermint and garlic reduced rice seed infection by Cochliobolus 

miyabeanus (Alice and Rao 1986). 

Garlic bulb extract inhibited the spore germination and mycelial growth of seed-borne 

fungal pathogens of jute, including Macrophomina phaseolina, Botryodiplodia theobromae and 

Colletotrichum corchori (Ahmed and Sultana 1984). 

Homeopathic drugs, Filixmas and Blatta orientalis, completely suppressed the population 

of Fusarium oxysporum in the seed mycoflora of wheat (Raka et al. 1989). 

Aspergillus ruber infection and weevil oviposition of Zabrotes subfaciatus were reduced by 

mineral oil and soybean oil treatment of dry beans stored in Ecuaddor (Hall and Harman 1991). 

- 114 -


Soybean oil, applied at a rate used to suppress grain dust, reduced storage fungi growth in 

maize and soybeans during 12 months in field storage bins in Iowa (McGee et al 1989, White and 

Toman 1994). 

BD 500 The vegetable seeds are treated with BD 500 for about 12 an hour and dried in the 

shade for about 1 hour. The seeds are then sown in the beds. Healthy plants are obtained and the 

germination of seeds is very good. Seeds treated with this method include Cowpea, Okra, Radish, 

Beans. 

It may be concluded that Microorganisms naturally present in agricultural ecosystems are 

environmentally compatible alternatives to traditional chemical methods for controlling storage pest 

and diseases and for seed treatment in organic seed production in particular. A serious 

impediment to bring many such microorganisms to the marketplace is the lack of knowledge of 

cultivation and formulation technologies needed to produce cells that are tolerant to the stresses of 

large-scale cultivation, separation, processing (drying or dewatering biomass), and storage. Ther 

is every scope of indegineous natural plant extracts to be effective means for maenagement of 

storage disease and pests. 

- 115 -


Reduced Risk Pesticides: The Best Alternative to Ensure Food 

Safety without Compromising Environment Quality 

S.N. Tiwari 

Department of Entomology, G.B.P.U.A.&T., Pantnagar- 263 145 (Uttarakhand) 

What are Conventional Reduced Risk Pesticides 

Pesticides that pose less risk to human health and the environment than existing 

conventional alternatives which are 

• neurotoxins, 

• carcinogens, 

• reproductive and developmental toxicants, 

• groundwater contaminants 

Advantages of Conventional Reduced Risk Pesticides 

• Low impact on human health 

• Lower toxicity to non-target organisms (birds, fish, plants) 

• Low potential for groundwater contamination 

• Low use rates 

• Low pest resistance potential 

• Compatibility with IPM 

Information required for Reduced Risk Assessment 

• Executive summary of chemical 

• Human health effects 

• Environmental fate and effects 

• Other hazards 

• Pest resistance and management (e.g., IPM) 

• Risk comparisons to registered alternatives 

• Comparative performance 

Factors considered to grant Reduced Risk Status 

Human health effects 

• very low mammalian toxicity 

• toxicity generally lower than alternatives (10-100X) 

• displaces chemicals that pose potential human health concerns e.g., OPs, probable 

carcinogens 

• reduces exposure to mixers, loaders, applicators and re-entry workers 

Classification of Pesticides : 

Classification of the 

insecticides 

Medium lethal dose by 

the oral route (acute 

toxicity) LD 50 mg/kg. 

Body weight of test 

animals 

Medium lethal dose by 

the dermal route 

(derma toxicity) LD 50 

mg/kg. Body weight of 

test animals 

1. Extremely Toxic 1-50 1-200 Bright red 

Colour of identification 

band on the label 

- 116 -


2. Highly toxic 51-500 201-2000 Bright yellow 

3. Moderately toxic 501-5000 2001-20000 Bright blue 

4. Slightly toxic More than 5000 More than 20000 Bright green 

Factors considered granting Reduced Risk Status 

Non-target organism effects (birds) 

• very low toxicity to birds 

• very low toxicity to honeybees 

• significantly less toxicity/risk to birds than alternatives 

• not harmful to beneficial insects, highly selective pest 

impacts 

Factors considered granting Reduced Risk Status 

Non-target organism effects (fish) 

• very low toxicity to fish 

• less toxicity/risk to fish than alternatives 

• potential toxicity/risk to fish less harsh 

• similar toxicity to fish as alternatives but significantly less exposure 


Groundwater (GW) 

• low potential for GW contamination 

• low drift, runoff potential 

• runoff mitigatable 


General factors 

• Lower use rates than alternatives, fewer applications 

• Low pest resistance potential 

• i.e. new mode of action 

• Highly compatible with IPM 

• Efficacy 

• Phytotoxicity 

Reduced Risk Insecticides 

Active ingredient 

Hexaflumuron 

Noviflumuron 

Tebufenozide 

Site of application 

Below and above ground termite bait stations 

Above ground bait station 

Cotton, Sugarcane, Mustard, Leafy veg., Brassica leafy veg, 

Fruiting veg., Tuberous & Corm vegetable, Turnip, Citrus, 

Grape, Walnut, Pome fruit, Berry crop group, Mint, tree nuts, 

Pecan, forestry, ornamentals, 

- 117 -


Buprofezin 

Indoxacarb 

Novaluron 

Acetamiprid 

Lambda-cyhalothrin 

Clothianidin 

Lufenuron 

Dinotefuran 

Methoxyfenozide 

Spiromesifen 

Etofenprox 

Spinosad 

Spinetoram 

Rice, Cotton, Mango, Grape, Chilies, cucurbit veg., head 

lettuce, almond, citrus, grape, tomato, bean (succ.), lychee 

fruits, pistachio, avocado, guava, peach, pome fruit, sugar 

apple 

Cotton, Cabbage, Chilies, Tomato, Pigeon pea, fruiting veg., 

brassica leafy veg., lettuce, sweet corn, pome fruit, alfalfa, 

peanut, potato, Soybean, fire ant bait, grape, 

Cotton, Cabbage, Tomato, Chilli, Gram, Apple, Pear, Peach, 

Plum, Blueberries Ornamentals, 

Cotton, Rice, pome fruit, citrus, grapes, brassica leafy veg., 

leafy veg. (excl.brassica), fruiting veg.,Ornamentals, potato, 

Cotton, Rice, Brinjal, Tomato, Chilli, Pigeon pea, Chick pea, 

Onion, Okra, Groundnut, Mango, legume vegetables, fruiting 

vegetables, sugarcane, termite barrier, 

Rice, Cotton, Canola, Corn (seed treatments), 

Cotton, Pigeon pea, Cabbage, Cauliflower, Termite bait station 

Rice, leafy vegetables, cotton, brassica head & stem 

subgroup, cucurbit vegetables, fruiting vegetables, grape, 

potato, Brassica leafy greens, Turnip (greens) 

Cotton, pome fruit, fruiting vegetables, grapes, brassica leafy 

vegetables,leafy vegetables, corn, stone fruit, tree nuts, 

cucurbits, okra, pea , soybean 

Brassica leafy vegetables, corn (field), cotton,cucurbits, fruiting 

vegetables, leafy greens, ornamentals, strawberry, tuberous & 

corm vegetables, tomato, bean, pea 

Rice 

Cotton, red gram, cereal grains, corn, oat, barley, millet, grain 

amaranth, peanut, Brassica leafy veg., Cabbage, Cauliflower, 

fruiting veg., leafy veg., cucurbit veg., Chillies, legume veg, 

leaves of root and tuber veg., okra, onion, turnip greens, 

asparagus, garden beet sugar beet (root), alfalfa, fruit fly bait, 

mint, Tropical fruit, almond, pistachio,apple, pome fruit, citrus, 

stone fruit, nuts, berry group, fig, grape, Non-grass animal feed 

Amaranth, pome fruit, stone fruit, artichoke, asparagus, 

avocado, banana, head & stem Brassica; Brassica leafy 

greens; bulb vegetables; bushberry; caneberry; cereal grains 

(ex. rice, sorghum, millet); cherimoya; citrus; corn (sweet); 

cotton; cranberry; cucurbit vegetables; custard apple; fig; 

foliage of legume vegetables; fruiting vegetables; grape; 

guava; juneberry; leafy vegetables; leaves of root & tuber 

vegetables; legume vegetables, lychee; mango; mint;okra; 

papaya; pea & bean, dried, soybean, pea & bean, peanut; 

pistachio; root & tuber vegetables; sorghum; lime; star apple; 

star fruit; strawberry; sugar apple; tree nuts; watercress, 

- 118 -


Chlorantraniliprole 

Spirotetramat 

Tolfenpyrad 

Bifenazate 

Cotton, Rice, Sugarcane, Cabbage, Grape, Pome Fruit, 

Potato, Stone Fruit, Brassica Leafy Vegetables, Cucurbit 

Vegetables, Fruiting Vegetables, Leafy Vegetables, Turf, 

Ornamentals, Tree Nuts, Pistachio, Artichoke, Asparagus, 

Caneberry, Cacao, Citrus,Coffee, Corn (field,sweet, pop), Fig; 

Forage,Fodder & Straw of Cereal Grains; Grass 

Forage,Fodder, & Hay; Herbs & Spices; Hops; Legume 

Vegetables (ex. soybean); Mint; Non-grass Animal Feeds; 

Oilseed Crops; Okra; Olive; Peanut; Pomegranate; Prickly 

Pear Cactus; Rice; Small Vine-climbing Fruits; Strawberry; 

Sugarcane; Tea; Tobacco; Tropical Fruits; Tuberous & Corm 

Vegetables, Termiticide Use 

Almond, Brassica Head & Stem Vegetables, Brassica Leafy 

Greens, Citrus, Cucurbits, Fruiting Vegetables, Grape, Hops, 

Leafy Vegetables, Onion, Pome Fruit, Stone Fruit,Strawberry, 

Tree Nuts, Tuberous & Corm Vegetables 

Ornamentals 

Ornamentals, stone fruit, edible-podded pea, tuberous & corm 

vegetables 

Acequinocyl Ornamentals, strawberry, almond, citrus, pome fruit, field 

ornamentals, 

Etoxazole 

Fenpyroximate 

Clofentezine 

Tolfenpyrad 

Cotton, pome fruit, strawberry, grape, tree nuts, 

Ornamentals, cotton, grape, pome fruit, citrus, hops, mint, 

pistachio, tree nuts 

Grape 

Ornamentals 

OP Alternative Insecticides: 

Fipronil 

Thiamethoxam 

Imidacloprid 

Emamectin benzoate 

Clothianidin 

Chlorfenapyr 

Cotton, Rice, Sugarcane, Cabbage, Chilli, home lawn, golf 

course, commercial and recreational turf and sod farms (fire 

ant), potting medium mixtures (fire ant), turf (homeowner, 

commercial; fire ant), 

Seed treatment (Cotton, Sorghum, Wheat, Okra, Barley, 

Canola, Sunflower ) 

Foliar (Cotton, Rice, Wheat, Mustard, Mango, Potato, Tomato, 

Brinjal, Tea, Citrus, cucurbit veg., fruiting veg., pome fruit, 

tuberous and corm veg., ornamentals, beans, stone fruit; mint, 

Seed treatment : Cotton, Rice, Sugarcane, Okra, Sunflower, 

Sorghum, Pearl millet, Chilli, Mustard, Foliar: Cotton, Rice, 

Sugarcane, Sunflower, Okra, Chilli, Mango, Citrus, Groundnut 

Cotton, Red gram, Chick pea, Brinjal, Okra, Cabbage, Chilli 

Rice, Cotton, Turf, Ornamentals, Pome fruit, Tobacco, 

Cabbage, Chili , Post construction control of termites 

- 119 -


Zeta-Cypermethrin 

Flonicamid 

Gamma-cyhalothrin 

Novaluron 

Deltamethrin 

Pymetrozine 

Etoxazole 

Alfalfa, corn (field, pop, sweet), head and stem brassica veg., 

leafy brassica greens, leafy veg., onion (green), sugar beet, 

sugarcane, rice 

Ornamentals, cotton, cucurbit vegetables, fruiting vegetables, 

pome fruit, potato, stone fruit, nursery & landscape ornamentals, 

head & stem Brassica, 

Wheat, alfalfa, Brassica head & stem subgroup, canola, corn 

(field, sweet), cotton, fruiting vegetables, garlic, legume 

vegetables (ediblepodded) subgroup, lettuce (head, leaf), tree 

nuts, onion (dry bulb), pea and bean dry shelled (except 

soybean) subgroup, pea and bean succulent shelled subgroup, 

peanut, pome fruit, rice, sorghum, soybean, stone 

fruit,sugarcane, sunflower, 

Cotton, Cabbage, Tomato, Chili, Bengal gram, pome fruit 

Corn, cucurbit vegetables, fruiting vegetables, onion , pome 

fruit, root & tuber vegetables, sorghum, tree nuts 

Asparagus 

Grape, tree nuts 

Reduced Risk Bird Repellent : 

Methyl Anthranilate 

Cherry, blue berry, grape, forestry 

Reduced Risk Fungicides 

Hymexazol 

Fludioxonil 

Mefenoxam (Metalaxyl-M) 

Azoxystrobin 

Sugar beet (seed treatment) 

Corn , strawberry, bulb vegetables, turf, caneberry, pistachio, 

stone fruit 

Maize, Millet, Sorghum, Sunflower, Mustard, Citrus, Cotton, 

Leafy vegetables, Nonbearing deciduous fruits and nuts and 

peanuts 

Wheat, barley, rice, oat, pea, onion, carrot, beans, potato, 

oilseed, grape, banana, peach, tomato, pecan, peanut ,almond, 

cucurbit veg, canola, potato, stone fruit, citrus, corn, cotton, 

leafy veg, root and tuber veg., soybean, leafy brassica greens, 

bushberry, eggplant, grass (grown for seed), jackfruit, 

juneberry, lingonberry, loquat, mint (spearmint, peppermint), 

okra, pawpaw, pepper, persimmon, salal, strawberry, tamarind, 

tropical fruit, turnip(greens), watercress, waxjambu, white 

sapote, legume vegetables, artichoke (globe), asparagus, head 

& stem Brassica subgroup, herbs, spices, safflower, 

Sunflower, Tomato, Chili, Mango 

- 120 -


Cyprodinil 

Fenhexamid 

Trifloxystrobin 

Zoxamide 

Fludioxonil 

Fluazinam 

Stone fruit, onion (dry bulb & green),Strawberry, bushberry, 

caneberry, 

pistachio, watercress, Brassica leafy vegetables,carrot, herbs, 

lychee fruits 

Grape, strawberry, ornamentals, almond, stone fruit, pear, 

pepper, pomegranate 

Pome fruit, grape, cucurbit veg., root vegetable, peanut, turf, 

banana, ornamentals, almond, fruiting veg., hops, potato, sugar 

beet, wheat, ornamentals, citrus, corn (field, pop),pecan, rice, 

stone fruit, barley, oats, 

Grape, cucurbit veg., tomato, 

Potato, Strawberry, bulb vegetables 

Seed treatments (brassica leafy veg., bulb veg., cereal grains, 

cotton, cucurbit veg., foliage of legume veg., fruiting veg., grass, 

herbs and spices, leafy veg., leaves and roots of tuber veg., 

legume veg., non-grass animal feeds, peanut, rape seed, root 

and tuber veg., sunflower) 

Groungnut, Potato 

Fenamidone Lettuce, cucurbit vegetables, onion, potato, Tomato, 

ornamentals, Grape 

Boscalid 

Fenhexamid 

Quinoxyfen 

Pyrimethanil 

Cyazofamid 

Flazasulfuron 

Berries, bulb vegetables, canola, fruiting vegetables, grape, 

legume vegetables, lettuce (head,leaf), peanut, root vegetables 

(except sugar 

beet, garden beet, radish, turnip), stone fruit,strawberry, tree 

nuts, tuberous & corm vegetables, turf, celery, spinach, 

Cucumber (greenhouse), fruiting vegetables, kiwifruit, leafy 

green subgroup (except spinach), stone fruit 

grape, cherry, lettuce, melons, pepper, strawberry 

Almond, grape, onion (dry bulb, green), pome fruit, stone fruit, 

strawberry, tomato, tuberous & corm vegetables 

Cucurbit vegetables, potato, tomato, Fruiting Vegetables, Grape 

(regional tolerance), Okra, Brassica Leafy Vegetables, Hops, 

Spinach, Turnip (greens) 

Turf 

Mandipropamid Brassica leafy vegetables, bulb vegetables, cucurbit 

vegetables, fruiting vegetables, grape, tuberous & corm 

vegetables, leafy vegetables 

Reduced Risk Herbicide 

Flumiclorac-pentyl 

Imazapic 

Metolachlor 

Imazamox 

Corn, soybean, cotton defoliant use 

Peanut 

Soybean 

Soybean, alfalfa, canola, legume veg., wheat, 

- 121 -


Carfentrazone-ethyl 

Diflufenzopyr 

Glyphosate 

s-Dimethenamid 

Carfentrazone-ethyl 

Flucarbazone sodium 

Prohexadione calcium 

Butafenacil 

Cyhalofop-butyl 

Imazethapyr 

Glufosinate ammonium 

Fluroxypyr 

Mesosulfuron methyl 

Penoxsulam 

Wheat, corn, cotton (defoliant use), turf, 

Corn, Grass 

Glyphosate-tolerant corn, canola, sugar beet, animal feed, nongrass 

group (exc. alfalfa); aloe vera; artichoke, globe; bamboo 

shoots; betelnut; buffalo gourd; chaya; crambe, seed; custard 

apple; flax; foliage of legume veg.; galangal root; ginger, white 

(flower); plum; grass, forage, fodder and hay group; herb and 

spices group; leafy veg.; leaves of root and tuber veg.; mustard 

seed; okra; palm heart; palm oil; papaya, pepper leaf; root and 

tuber veg.; sesame seed; Spanish lime; stevia (leaves); cherry; 

water spinach 

Non-crop area, Tea 

Corn, soybean, peanut 

Cereal grains, Wheat 

Wheat 

Apple 

Cotton 

Rice 

Rice, Soybean, Groundnut 

Rice, Tea 

Corn 

Wheat (along with Iodosulfuron Methyl Sodium) 

Rice, turf, Grape, Tree Nuts 

Bispyribac-sodium 

Mesotrione 

Pinoxaden 

Saflufenacil 

Aminopyralid 

Fluthiacet-methyl 

Alternative) 

(OP 

Rice, Turf 

Sugarcane, Corn, Turf, Berry group, Flax, Asparagus, Grass, 

Oat, Okra, Sorghum, 

Barley, wheat 

Cereal Grains; Citrus; Cotton; Foliage of Legume Vegetables; 

Forage, Fodder, & Straw of Cereal Grains; Grape; Legume 

Vegetables; Pome Fruit; Stone Fruit; Sunflower; Tree Nuts 

Range & pasture lands, rights of way, roadsides, industrial 

vegetation management 

Cotton 

Further Risk Reduction 

• By Selectivity 

Action Required 

• Introduction of concept 

• Subsidy on RR Pesticides 

- 122 -


Trichoderma as Inducer of Plant Resistance to Diseases 

R.P. Singh & Bhanu Pratap Bhadauria 


Trichoderma spp. is fungi that are present in nearly all agricultural soils and in other 

environments such as decaying wood. The antifungal abilities of these beneficial microbes have 

been known since the 1930s, and there have been extensive efforts to use them for plant disease 

control since then. Trichoderma species are among the most widely used biological control agents 

against soil borne plant pathogens. Biological control mechanisms of this fungus are competition, 

antibiosis and parasitism. In fact, we do not know whether most of the benefits of Trichoderma 

occur because they directly attack and control disease-causing fungi, as has long been believed, 

or because they have direct effects upon plants. Many recent findings suggest that plant 

development and biochemistry are strongly affected by Trichoderma strains. The capability of T. 

harzianum to promote increased growth response has been established. A 30% increase in 

seedling emergence and 95% increase in root area have been reported. It is also known to 

stimulated nutritional adsorption (Harman et al., 2004). Specific strains of fungi in the genus 

Trichoderma colonize and penetrate plant root tissues and initiate a series of morphological and 

biochemical changes in the plant, considered to be part of the plant defense response, which in 

the end leads to induced systemic resistance (ISR) in the entire plant. Until recently, research on 

Trichoderma-plant interactions focused mostly on mycoparasitic aspects of plant protection. Only a 

few studies so far have dealt with plant defense responses induced by Trichoderma (Chang et al. 

1997; Yedidia et al. 1999; Yedidia et al. 2000; Martinez et al. 2001). Considering that Trichoderma 

acts in rhizosphere, the effect of native formulations of the mycoparasite on defense responses in 

plant leaves has been a neglected aspect in plant resistance studies. 

Plants possess various inducible defense mechanisms for protection against pathogen 

attack. An example of this is systemic acquired resistance (SAR), which is activated by a wide 

range of pathogens, especially (but not only) those that cause tissue necrosis. Similarly, 

colonization of plant roots by certain non pathogenic rhizobacteria can induce systemic resistance 

(ISR) in the host plant. Both pathogen-induced SAR and rhizobacteria-mediated ISR are effective 

against different types of pathogens, and are typically characterized by a restriction of pathogen 

growth and a suppression of disease development compared with primary infected, non-induced 

plants. However, the signaling pathways controlling pathogen-induced SAR and rhizobacteriamediated 

ISR differ. Whereas SAR requires endogenous accumulation of salicylic acid (SA), the 

signalling pathway controlling ISR functions independently of SA and requires intact 

responsiveness to the plant hormones jasmonic acid (JA) and ethylene. Additionally, it has been 

established that accumulation of phytoalexins and other low molecular weight antimicrobial 

metabolites is integral to plant protection. The chemical structures of phytoalexins vary among 

different plant families and include flavonoids, terpenoids and indoles (Darvill and Albersheim , 

- 123 -


1984). 

Processes Involved in Induced Systemic Resistance 

Perception by plant cells of elicitors produced by the inducing agent that initiate 

phenomenon 

Signal transduction that is needed to propagate the induced state systemically through 

the plant 

Expression of defense mechanisms that limit or inhibit further pathogen penetration in 

to host tissues. 

Resistance-inducing traits of beneficial microbes 

Microbial determinants that contribute to induced resistance as triggered by beneficial 

microbes are best studied for fluorescent Pseudomonas spp. In analogy to the microbe-associated 

molecular patterns (MAMPs) flagellin and lipopolysaccharides (LPS) of pathogenic Pseudomonas 

spp., it was found that these cell surface components of beneficial Pseudomonas spp. are potent 

inducers of the host immune response. Antibiotics, which are produced by some beneficial 

microorganisms, can also function as MAMPs in triggering the immune response. 

MAMPs involved in systemic resistance triggered by beneficial fungi are not well studied. 

Trichoderma-derived xylanase and cellulase are well known inducers of ethylene biosynthesis. It 

was shown that cellulase treatment leads to activation of defense mechanisms in melon 

cotyledons (Martinez et al. 2001). Djonovic et al. (2006) demonstrated that the hydrophobin-like 

elicitor Sm1 of the beneficial soil-borne fungus Trichoderma virens induces systemic resistance in 

maize. Maize plants grown with SM1-deletion strains or SM1-overexpressing strains displayed 

decreased or enhanced levels of systemic disease protection, respectively, demonstrating its role 

in triggering host defense. Peptaibols are linear peptide antibiotics produced by Trichoderma and 

other fungal genera. In the biocontrol agent and inducer of plant defense responses Trichoderma 

virens, enzymes forming peptaibols are encoded by tex1 and disruption of these genes led to a 

significantly reduced systemic resistance response in cucumber plants against the leaf pathogen 

Pseudomonas syringae pv. lachrymans as compared with plants grown in presence of the wildtype. 

Two synthetic 18-amino-acid peptaibol isoforms induce systemic protection when applied to 

cucumber seedlings suggesting that these peptides are critical in the chemical communication 

between Trichoderma and plants as triggers of defense responses. However, the peptaibol 

alamethicin induced a form of active cell death in Arabidopsis thaliana cell cultures and caused 

lesions in leaves of plants after a few days showing that these molecules may also retain some 

phytotoxicity on certain plant species. It has also recently been demonstrated that some other 

secondary metabolites of plant beneficial Trichoderma spp. such as harzianolide and pentylpyranone 

may have a role in activation of plant defense responses. 

Peroxidase and polyphenol oxidase are oxidative enzymes contributing to defense against 

pathogens. The peroxidase activity increases in plants during pathogen infection and has been 

- 124 -


correlated with resistance. High activity of peroxidase increased the ability of transgenic tobacco 

plants to suppress growth of the pathogenic bacterium Erwinia carotovara.. Several previous 

experiments have demonstrated the importance of polyphenol oxidase-mediated phenolic 

oxidation in restricting plant disease development. For example polyphenol oxidase-over 

expressing tomato plants were shown to exhibit a great increase in resistance to P. syringae. 

Compared with control plants, these transgenic lines showed less severity of disease symptoms, 

with over 15-fold fewer lesions, and strong inhibition of bacterial growth, causing more than 100- 

fold reduction of bacterial population in the infected leaves. Consequently, high activities of 

peroxidise and polyphenol oxidase can be components of resistance against pathogens, including 

bacteria. 

Ethylene is an important factor in the regulation of plant reaction to pathogens. An increase 

of ethylene formation in pathogen-challenged plants has been related both to defense responses 

leading to resistance as well as to symptom development during pathogenesis. The role of 

ethylene in incompatible interactions is mostly contradictory and depends on the pathogen used. 

Similarly, regarding to susceptible responses, ethylene insensitivity may lead to both increases 

and decreases of symptom development. In addition, recent findings indicate the role of ethylene 

in induced systemic resistance. The fact that ethylene is a known inducer of several pathogen 

defense-related enzymes, e.g. peroxidase, glucanase, and chitinase, lends support to the 

regulative role of ethylene in resistance responses. Examples of Plant –Pathogen system where 

induced resistance by Trichoderma spp. have been reported is given in table-1. 

Table-1: Induced Resistance in Plant by Trichoderma species 

Species and 

strain 

T. virens 

G-6,G-6-5 and 

G-11 

T. harzianum 

T-39 

T. harzianum 

T-39 

T. asperellum 

T-203 

Plant Pathogens Evidences or effect Time 

after 

Appli. 

Cotton 

Bean 

Tomato 

Pepper 

Tobacco 

Lettuce 

Bean 

Rhizoctonia 

solani 

Colletotrichum 

lindemuthianum 

Botrytis cinerea 

Protection of plants, 

induction of fungitoxic 

terpenoid phytolexins 

Protection of leaves 

when T-39 was present 

only on roots 

B. cinerea Protection of leaves 


only on roots 

Cucumber Pseudomonas 

syringae 

pv,lachrymans 



only on roots, production 

of antifungal compounds 

in leaves 

4 

days 

10 

days 

7 

days 

5 

days 

Efficacy 

78% 

reduction in 

disease 

48% 

reduction in 

lesion area 

25-100% 

reduction 

Up to 80% 

reduction in 

disease on 

leaves & 

100% on 

stem 

- 125 -


T. harzianum 

T-22, 

T. atroviride 

P1 

T. harzianum 

T-1 & T-22, T. 

virens T3 

T. harzianum 

T-22 

T. harzianum 

T-22 

Trichoderma 

GT3-2 

Bean 

B. cinerea, 

X. campestris 

pv. phaseoli 

Cucumber Green mottle 

mosaic virus 


when T-22 or P1 was 

present only on roots, 

production of antifungal 

compounds in leaves 


when Trichoderma strain 

were present only on 

roots 

Tomato A. solani Protection of leaves 



roots 

Maize C. graminicola Protection of leaves 



roots 

Cucumber C. orbiculare, 

P. syringae pv. 

lachrymans 

T. harzianum Pepper Phytophthora 

capsici 

T. harzianum 

NF-9 

Rice 

Magnaporthe 

grisea, 

X. oryzae pv. 

oryzae 




roots, Induction of 

lignification & superoxide 

generation 

Protection of stem when 

Trichoderma strain were 

present only on roots, 

inhanced production of 

the phytolexin capsidol 


when NF-9 was present 

only on roots 

7-10 

days 

7 

days 

3 

month 

14 

day 

69% & 54% 

respectively 

Reduction 

in growth 

eliminated 

Up to 80% 

reduction in 

disease 

44% 

reduction in 

lesion size 

1 day 59% 

52% 

protection 

respectively 

9 

days 

14 

days 

40% 

reduction in 

lesion 

length 

34-50% 

reduction in 

disease 

Induced defense signalling pathways 

It is probable that MAMPs of beneficial microbes and pathogens are recognized in a largely 

similar manner, ultimately resulting in an enhanced defensive capacity of the plant. However, in 

plant–beneficial microbe interactions, MAMP-triggered immunity does not ward off the interacting 

beneficial as it remains accommodated by the plant. This suggests a high degree of coordination 

and a continuous molecular dialog between the plant and the beneficial organism. The local and 

systemic defense responses that are triggered by beneficial and parasitic microorganisms are 

controlled by a signalling network in which the plant hormones salicylic acid (SA), jasmonic acid 

(JA), and ethylene (ET) play important roles. There is ample evidence that SA, JA, and ET 

pathways cross communicate, allowing the plant to finely tune its defense response depending on 

- 126 -


the invader encountered (Koornneef and Pieterse, 2008). ISR, which is triggered by beneficial 

microorganisms like Trichoderma spp. requires components of the JA and ET signalling pathway 

(Pieterse, 1998). Both pathogen-induced SAR and Trichoderma spp. - triggered ISR are controlled 

by the transcriptional regulator NPR1 (Pieterse and Loon, 2004). List of MAMPs identified in 

different Trichoderma spp. is given in table-2. 

Table-2: Tricoderma MAMPs Identified in Different Species 

MAMP/ Effector Tricoderma 

Activity 

species 

PROTEINS 

Xylanase Xyn2/Eix T. viride A xylanase that elicits ET biosynthesis and 

hypersensitive response in tobacco leaf tissues 

Cellulases T. longibrachiatum Activated and heat-denatured cellulases elicit 

melon defences through the activation of the 

Cerato-platanins 

Sm1/Epl1 

T. virens/ 

T. atroviride 

SA and ET signalling pathways, respectively 

Hydrophobin-like SSCP orthologues that can 

induce expression of defence response in 

cotton and maize 

Swollenin TasSwo T. asperelloides Expansin-like protein with a cellulose-binding 

domain capable of stimulating local defence 

responses in cucumber roots & Leaves & 

affording local protection against B. cinerea & 

P. syringae 

Endopolygalacturonase 

ThPG1 

T. harzianum Involved in active colonization of tomato root & 

ISR-like defense in Aradiopsis 

SECONDARY METABOLITES 

Alamethicin 

(20mer peptaibol) 

T. viride Elicitation of JA & SA biosynthesis in Lima 

bean 

Trichokonin 

(20mer peptaibol) 

T. pseudokoningii Induces the production of ROS, the 

accumulation of phenolic compounds at the 

application site & virus resistance in tobacco 

plants through multiple defense signallling 

pathways 

18mer Peptaibols T. virens Elicitation of cucumber systemic defenses 

6-Pentyl-α-pyrone, 

horzianolid 

harzianopyridone 

& 

against P. syringae 

Various Low- conc. metabolites activating plant 

defense mechanisms & regulating plant growth 

in pea, tomato & canola 

Limitations of Induced Systemic Resistance 

Dependence on environmental condition 

Only partial protection 

Problem of mass multiplication, storage and application 

Phytotoxicity 

Resurgence 

Effect on quality 

Safety 

- 127 -

REFERENCES 


• Chang, P.F.L., Xu Y., Narasimhan, M.L., Cheah, K.T., D’Urzo, M.P., Damsz B., Kononowicz, A.K., 

Abad, L., Hasegawa, P.M., Bressan, R.A. 1997. Induction of pathogen resistance 

and pathogenesis-relatedgenes in tobacco by a heat-stable Trichoderma mycelial 

extract and plant signal messengers. Physiol. Plant. 100: 341–352. 

• Darvill, AG, Albersheim, P. 1984. Phytoalexins and their elicitors a defense against microbial 

infection in plants. Annu Rev Plant Physiol. 35:243–275. 

• Djonović, S.; Vargas, W.A.; Kolomiets, M.V.; Horndeski, M.; Wiest, A.; Kenerley, C.M. 2007. A 

proteinaceous elicitor Sm1 from the beneficial fungus Trichoderma virens is 

required for induced systemic resistance in maize, Plant Physiol, 145 : 875–889. 

• Harman, G.E., Howell, C.R., Viterbo, A., Chet, I. and Lorito, M. 2004. Trichoderma species 

• opportunistic, avirulent plant symbionts. Microbiology, 2: 43-56. 

• Koornneef, A. and Pieterse, C. M. J. 2008. An informative overview of molecular mechanisms 

involved in crosstalk between defense signaling pathways, Plant Physiol, 146: 839– 

844. 

• Martinez, C., Blanc, F., Le Claire, E., Besnard, O., Nicole, M., Baccou, J.C. 2001. Salicylic acid 

and ethylene pathways are differentially activated in melon cotyledons by active or 

heat-denatured cellulase from Trichoderma longibrachiatum. Plant Physiol. 127: 

334–344. 

• Pieterse, C.M.J.; Van Wees, S.C.M.; Pelt, J.A. Van; Knoester, M.; Laan, R.; Gerrits, H.; Weisbeek, 

P.J. and Loon, L.C. Van. 1998. A novel signaling pathway controlling induced 

systemic resistance in Arabidopsis, Plant Cell, 10: 1571–1580. 

• Pieterse, C.M.J. and Loon, L.C. Van. 2004. NPR1: the spider in the web of induced resistance 

signaling pathways. Curr Opin Plant Biol, 7: 456–464. 

• Yedidia, I., Benhamou, N., Chet, I. 1999. Induction of defense responses in cucumber plants 

(Cucumis sativus L.) by the biocontrol agent Trichoderma harzianum. Appl. Env. 

Microbiol. 65: 1061–1070. 

• Yedidia, I., Benhamou, N., Kapulnik, Y., Chet, I. 2000. Induction and accumulation of PR proteins 

activity during early stages of root colonization by the mycoparasite Trichoderma 

harzianum strain T-203. Plant Physiol. Biochem. 38: 863–873 

- 128 -


Influence of Environmental Parameters on Trichoderma Strains with 

Biocontrol Potentials 

A.K. Tewari 

Department of Plant Pathology, G.B. Pant Univ. of Agric. & Tech., Pantnagar- 263 145 (UK) 

Trichoderma genus is one of the most common soil fungi, isolated from various habitats, 

This is also known for secreting secondary metabolites in the environment which affects on wide 

spectrum of various fungal groups, especially pathogenic fungi. Reports by various workers show 

that Trichoderma spp. is a powerful antagonists of parasitic soil fungi of Pythium,Phytophthora, 

Sclerotinia, Sclerotium, Rhizoctonia, Fusarium, Verticillium and Gaeumannomyces, 

In recent times Biological control is an important component of IPM system instead of its 

independent use. In most of the cases the bioagents are effective in laboratory or greenhouse 

conditions only, and not all that successful under field conditions. The investigations on 

epidemiological aspects of the disease as well as developments of the bioagents are, therefore, 

crucial to keep the biocontrol recommendations under varying environmental conditions. Among 

fungal bioagents, Trichoderma is very promising candidates for the biological control of plant 

pathogenic fungi. When planning the application of antagonistic Trichoderma strains for the 

purposes of biological control, it is very important to consider the environmental parameters 

affecting the biocontrol agents in the soil. The environment (the effects of temperature, water 

potential and pH) effectiveness of antagonist and its ability to survive in an ecosystem , host 

exudates presence of chemicals , metal ions, and the antagonistic bacteria in the soil are 

important factors to decide the fate of biological control of plant pathogens. In spite of various 

abiotic factors biotic factors of antagonists like; ability to colonize the substrate and competent with 

other microorganism in the niche, production. of chlamydospores which can sustain for a longer 

period of time even in adverse climatic conditions, germination and recovery time of the spore, 

release from formulation ,doubling time/linear growth rate and movement to the site of action of the 

antagonist also plays a major role for the antagonistic potential of the Trichoderma 

Most of the Trichoderma strains are mesophilic and grow well in a wide range of 

temperature from 15-35 0 C. Low temperatures in winter may cause a problem during biological 

control by influencing the activity of the Trichoderma. Trichoderma cannot tolerate dry conditions; 

however, we may need these agents against plant pathogenic fungi which are able to grow and 

cause disease even in dry soils. The pH characteristics of the soil is also considered to the most 

important parameters affecting the activities of mycoparasitic Trichoderma strains. Trichoderma 

strains were able to grow in a wide range of pH from 2.0 – 6.0 with an optimum at 4.0. 

Mycoparasitic Trichoderma strains were found to be able to display various enzyme activities 

under a wider range of pH values 3.0- 6.0.Trichoderma are more effective in acidic soil , however 

Pseudomonas fluorescence are more effective in slightly alkaline soil ( above pH 6.5) . 

In the IPM strategy, we may have to combine Trichoderma strains with chemical 

- 129 -


pesticides or metal compounds, therefore it is important to collect information about the effects of 

pesticides and metal ions on the biocontrol strains. Antagonistic soil bacteria may also have 

negative effects on the biocontrol abilities of Trichoderma strains, therefore it may be 

advantageous if a biocontrol strain possesses bacterium- degrading abilities as well. 

The number of studies about the effects of different environmental factors on mycoparasitic 

Trichoderma strains is increasing from year to year, indicating, that in order to reach effective 

biological control, it is necessary to broaden our knowledge about the epidemiology and 

ecophysiology of the Trichoderma. The application of mycoparasitic Trichoderma strains with 

improved tolerance of unfavorable environmental conditions could increase the efficacy of 

biological control. The breeding of Trichoderma for cold-tolerance, osmotolerance, bacteriumtolerance, 

pesticide- or metal-resistance may result in effective mycoparasitic strains for biocontrol 

application against fungal plant pathogens under a wider range of environmental conditions. 

- 130 -


Smut Fungi: Potential Pathogens and Biocontrol Agents 

K. Vishunavat 


Smuts and bunts referto a particle of dirt or a smudge made by soot, smoke, or dirt.The 

smuts are fungi, mostly Ustilaginomycetes (of the class Teliomycetae, subphylum Basidiomycota), 

that cause plant disease. Several important genera include Ustilago, Sphacelotheca, 

Tolyposporium, Tilletia, Entyloma, and Urocystis. The disease is initiated when soil-borne, or in 

particular seed-borne, teliospores germinate and eventually produce hyphae that infect 

germinating seeds by penetrating the coleoptile before plants emerge or through spores 

dissiminated to infect the reproductive organs. 

1. Nuclear Cycle of smut fungi 

The life cycle of smut fungi is partly dictated by the heterothallic nature of the fungus. When 

primary and secondary sporidia (basidiospores) ,each having a single haploid nucleus germinate, 

they produce monokaryotic (1N) hyphae. At some unknown point in the life cycle of the pathogen, 

monokaryotic hyphae of different, compatible mating types fuse to produce dikaryotic (1N + 1N) 

hyphae. This dikaryotization most likely occurs on the plant surface just prior to penetration or 

within the plant tissue after penetration by the hyphae. At some later time, fusion (karyogamy) of 

compatible nuclei occurs within the dikaryotic hyphae, and teliospores develop. 

2. Infection by Smut fungi 

Types of infection in smut fungi 

Seedling infection 

The smut spores are usually smooth walled, externally seed borne, germinate with the 

seed germination. The infection of the seedling takes place before its emergence out of the soil. 

Change of haplophase to diplophase takes place before infection. 

Floral or blossom infection or intraseminal infection 

Rough walled wind blown spores fall onto the fresh flowers where they germinate to cause 

infection of the ovary after diplodization. The binucleate hyphae reach the embryo, remify, and 

become dormant with maturity of the seed. The infection thus carried internally with the seed and 

when the later germinates, the fungus also grows up and finally appears as black powdwery mass 

in the inflorescence. 

Shoot infection 

This is usually local infection. Spores are carried through wind currents and fall on to the 

young buds, young flowers , developing seeds , or may fall on the ground , perennate there 

ultimately germinate next year causing infection of the host parts through wind blown sporidia. 

According to effect on host the smut may be: 

Ovariculous 

The inflorescence develop normally and the ovary also functions in the normal way but the 

- 131 -


content of the ovary are ultimately destroyed and replaced by the smut spore masses.Loose smut 

in which the wall of the ovary is eaten away and the smut spores are easily blown off. Another 

example is covered smut in which ovary wall remain intact thus keeping the spores together 

unless the wall is mechanically broken. 

Culmiculous: The full development of the inflorescence is suppressed. 

Role of environmental conditions and soil borne inoculum in causing smut diseases of 

cereals 

(i) Loose smut of wheat 

The level of loose smut infection in wheat varies according to weather conditions during the 

flowering period of the crop . Cool, moist conditions extend the flowering period, giving loose smut 

spores more chance to infect the open flowers. Seed produced in cool wet seasons is likely to 

carry increased infection levels, whereas hot dry conditions at flowering time may reduce the 

infection level. 

(ii) Covered smuts / common bunt/ stinking smut/ hill smut of wheat 

Pathogen is soil borne or may be carried through seed.Spores are so hardy that they may infect 

wheat crop even after 10 year in soil and after passage through the digestive tracts of cattle and 

sheep may infect wheat crop. Soil temperature, moisture, type of soil fertility, host variety 

,physiological races, spore load, depth and rate of sowing and day length have marked influence 

on spore germination and subsequent infection. 

(iii) Covered smut of barley Ustilago hordei 

The black spore mass of this smut remains covered by more or less firmly adhering 

membranes of the grain and the basal parts of the glumes. Fungus is externally seed borne. The 

spores adhere on seed surface while threshing.The seedling infection is influenced by soil 

moisture and soil temperature. Optimum temperature for spore germination is 20 o C and the 

maximum 35 o C. The period of infection is limited to the period between germination and 

emergence of the seedling. Deep sowing lengthens the period of susceptibility. Shallow sowing 

reduces disease incidence 

Cool soil temperature, high moisture helps to reduces infection. 

(iv) Loose Smut of Oat (Ustilago avenae) 

The infection is seed borne (dormant mycelium in the pericarp) or seed contamination 

(spore adhere on seed surface during threshing).The soil environment is essential factor in 

determining the severity of infection.Optimum temperature for spore germination is 15-28 0 C while 

maximum is 31-34 0 C and minimum is 4-5 0 C.High soil temperature and low soil moisture favours 

the disease. 

(v) Smut of maize Ustilago maydis 

The fungus survives on mature heaps and crop refuses and these serve as main source of 

harboring inoculum. The fungus produce Gall on the infected cob, stem, leaves, axillary buds and 

- 132 -


parts of the male flower tissues. The saprophytic phase may be as prolonged as the fungus go on 

growing indefinitely on fresh nutrient solutions.Not much work has been done in India due to 

obscure nature of the disease. 

(vi) Loose smut of sorghum (Sphacelotheca cruenta) 

In the ear head, spiketets are affected and grains get converted into the sori .The spores 

are formed in ovary and floral bracts.The fungus is both soil borne and externally seed borne. 

Spores remain viable for four years in dry conditions. Spores germinate best at 18-20 0 C .Low 

temperature, low soil moisture, and deep sowing favours infection. 

(vii) Head smut sorghum (Sphacelotheca reilianum) 

Entire inflorescence gets converted into a big sorus.The soil borne inoculum is major 

source of infection although pathogen may be externally seed borne. Soil temperature and 

moisture are main factors responsible for survival of spores.Dry cool soil favours survival while 

moist and warm soil reduces survival. Application of low C: N organic amendments reduce 

inoculum density.The disease is more in crop grown in clay loam soil (high moisture) than in sandy 

loam soil. Frequent irrigation after sowing reduces disease incidence. Deep sowing show high 

disease incidence. Application of urea, ammonium sulphate, and triple-super-phosphate reduces 

disease incidence. 

(ix) Long smut of sorghum Tolyposporium ehrenbergii) 

Few grains in an ear are transformed into smut sori.The primary inoculum may be 

introduced by some alternative host. The disease is air borne in nature and wind blown spores fall 

on to bud and initiate a mycelium which is expressed in heads. Spores germinate at 15-36 0 C 

optimum by 28 0 0 C. Seed treatment is therefore of no use.Crop rotation, field sanitation helps to 

reduce the disease. The varieties with covered glumes may escape infection. 

(x) Smut of pearl millet (Tolyposporium penicillariae) 

The pathogen is soil borne. Sori are on scatterd grain in the ear. Spores are held in balls. 

On germination they give rise to sporidia which are carried by air current towards the floral axis 

and settle down on the florets immediately cause infection .Similar to the long smut disease ,crop 

rotation, field sanitation help to reduce the infection and the varieties with covered glumes may 

escape infection . 

(xi) Covered smuts / common bunt/ stinking smut/ hill smut of wheat (Tilletia caries or T. 

foietidia) 

Pathogen is soil borne or may be carried through seed as externally seed borne infection . 

Spores are so hardy that they may infect wheat crop after 10 year of storage in soil and after 

passage through the digestive tracts of cattle and sheep may infect wheat crop.Soil temperature, 

moisture, type of soil fertility, host variety, physiological races, spore load, depth and rate of 

sowing and day length have marked influence on spore germination and subsequent infection. 

(xii) Covered smuts / common bunt/ stinking smut/ hill smut of wheat (Tilletia laevis) 

The temperature for spores to germinate are, 0-4 0 C minimum, 18-20 0 C optimum and 36 0 C 

- 133 -


the maximum. Different races behave differently as regard to their temperature requirement. Low 

soil temperature and high soil moisture are conducive for disease development.Optimum soil 

temperature favouring disease is 9-12 0 C .The planting during high temperature effectively reduce 

disease incidence. Shallow sowing reduces disease incidence while deep sowing increases the 

disease. 

(xiii) Karnal bunt Neovossia indica ( Tilletia indica) 

The Pathogen is soil borne or may be carried through seed on seed surface. Spore may 

remain viable in soil for 4-5 years.The survival of spores depends upon the depth in soil. The 

viability of spore decreases with the increase in depth of soil. The environmental conditions in 

Northern India in the month of Mid February or early march favors spore germination. Good 

teliospore germination in soil is at 15% or above soil moisture. Irrigation, cloudy or foggy weather 

for 7-10 days in December to March, and at minimum average temperature of 3.7 0 C and 

maximum 27.5 0 C, is good for teliospore germination. However, for disease to develop high 

humidity frequent light rains, cloudy weather, and low temperature at the time of flowering are 

required. Excessive irrigation and nitrogen fertilizers show heavy incidence of bunt. High microbial 

population by green manuring and fertilizer in soil show low bunt incidence. 

(ivx)Bunt of rice ( Tilletia horrida) 

Few grains in the ear get converted into black powder mass in the husk.Spores survive in 

soil, or go with seed awns and partially infected grains.Spores remain viable for 2-more years in 

soil. Disease is more common in light than in heavy soil. Heavy nitrogen fertilizers make plant 

susceptible to disease.However, temperature of 25-30 0 C and high humidity ( 85% or more ) with 

intermittent showers at the time of ear emergence favours infection. 

(vx) Leaf smut of rice ( Entyloma oryzae ) 

Black spots covered by the epidemis and having black smut spore underneath in 

leaves.The fungus survive on diseased leaf trash in soil. High nitrogen application in soil enhances 

disease. 

(vix) Flag smut of wheat (Urocystis tritici) 

The pathogen is soil and seed borne. The fungus persists in soil for many years.Sowing in 

moist soil enhances disease. Seed when sown through broadcasting in dry land, harrowed and 

then irrigated show low disease incidence.The minimum, optimum and maximum temperature for 

spore to germinate is 5, 20 and 28 0 C .Soil with excessive Ca macronutrient favors disease.Deep 

sowing enhances disease. 

Classical examples of smut fungi as bioagents 

Ustilago maydis is unique amongst biological weapons in that it is not only edible, but 

considered highly desirable. In Mexico, galls on sweet corn are known as huitlacoche and they can 

be more valuable than the plant itself. Farmers may therefore try to spread the disease when 

plants are seen to be infected. 

- 134 -


Tilletia ehrhartae: A seed infecting fungus (Tilletia ehrhartae) could provide a biological control for 

an invasive Veldt grass (Ehrharta calycina) in South Africa and Australia. 

Similarly , white smut fungus (Entyloma ageratinae) a native of Jamica and Maxico may 

be used as biocontrol agent for successful biocontrol programme against mist flower (Ageratina 

riparia ) in Hawaii .The fungus was released to some worst mist flower infested areas in north 

Island and New Zealand in 1998 establishing readily and quickly becoming common. 

- 135 -


Biocontrol of Fungal Phytopathogens by Trichoderma spp. 

Lakshmi Tewari, Disha Sharma and Rajkumar Pandey 


Biological control of phytopathogens by antagonistic organisms is a potential, non chemical 

and more eco friendly tool for crop protection. Trichoderma species are considered as one of the 

most important biocontrol fungi for improving plant growth and protecting crops from several fungal 

plant pathogens (Harman 2000). Most of the chemical pesticides used to control plant diseases 

and phyto-pathogens are highly toxic and harmful for the human beings causing environmental 

hazards also. An effective alternative or supplement to these chemical pesticides is biological 

control (cook and baker, 1983). Biological control strategy is highly compatible with sustainable 

agriculture and has a major role to play as a component of integrated pest management (IPM) 

programme. 

Figure1: Morphological features of Trichoderma harzianum 

Trichoderma sp. are free living soil fungi that are highly interactive with other rhizosphere 

micro flora in root, soil and foliar environments. Mycoparasitic activity and antibiotic production 

potential were first demonstrated in Trichoderma lignorum by Weindling (1932). One of the most 

interesting aspects of studies on Trichoderma is its potential to employ varied mechanisms for 

disease control. In general the fungus exhibits a preference for wet soil. The iron content of the 

- 

soil, HCO 3 , salt and organic matter content, presence or absence of other microbes in soil are 

also important determinants of micro site preference by Trichoderma sp. The genus Trichoderma 

was introduced by Persoon almost two hundred years ago and was isolated from soil 

decomposing matter. Trichoderma for the most part classified as imperfect fungi in that they 

produced only asexual spores; the sexual stage when found is within the Ascomycetes in the 

genus Hypocrea (Harman, 2002), Rifai (1969) outlined the speciation concept within the genus 

Trichoderma and described nine species aggregates. With the use of molecular approaches 

particularly sequence polymorphism with internal transcribed spacer (ITS) regions of nuclear 

ribosomal DNA (rDNA), the texa recently have gone from nine to at least 35 species ( Hayes et al, 

1994). The conidiophores are highly ramified and phailides are flask shaped or ovoidal (Hermosa 

et al, 2000). 

Biocontrol Potential of Trichoderma species 

Since the pioneer work of Weindling, several reports on successful biocontrol of fungal 

- 136 -


phytopathogens by Trichoderma sp. have accumulated. Among Trichoderm. most widely reported 

and commonly used biocontrol species are T.harzianum, T. viride and T. virens. They have been 

reported to inhibit many soil borne pathogenic fungi such as Fusarium, Pythuim, Sclerotium, 

Rhizoctonia, Sclerotinia, Macrophomia sp. etc., which are the major wilt causing fungal pathogens 

of various crops. 

T. harzianum has potential for biological control of sheath blight of rice by antagonizing the 

pathogen Rhizoctonia solani (Tewari and Singh, 2005). Today Trichoderma strains are used for 

biological control, either alone or in combination with other microbes or chemical adjuvants. They 

are known to produce a wide range of antibiotic substances and parasitize other fungal phytopathogens. 

They also compete with other soil microorganisms for key exudates from seeds and 

roots that stimulate germination of propagules of plant pathogenic fungi in soil, nutrients and 

space. They are also known to produce certain lytic enzymes that degrade the cell wall of the 

pathogen. Besides these direct inhibitory effects on pathogens, Trichoderma sp. exerts beneficial 

effects on plant growth and development. These versatile fungi are highly efficient producers of 

many extra-cellular enzymes like cellulases, chitinases, glucanases, proteases etc. Growth 

enhancement by Trichoderma sp. has been observed even in the absence of any detectable 

disease and in sterile soil and is not considered to be a side effect of suppression of disease or 

minor plant pathogens. 

Mechanisms Involved in Biocontrol of Fungal Phytopathogens by Trichoderma sp. 

Trichoderma sp. uses a variety of mechanisms to provide protection against several plant 

pathogens and/or plant diseases and enhance plant growth, such as it may (i) directly kill the 

pathogens by mycoparasitism and/or antibiosis, (ii) adversely affect the growth and development 

of the pathogen by competing for the nutrients, oxygen or space (iii) alter fitness of the pathogen, 

(iv) induce systemic plant resistance, (v) enhance plant growth and its tolerance to stress, (vi) 

metabolize plant exudates supporting pathogen, and /or (vii) inactivate enzymes produced by the 

pathogens and (viii) synthesize cell wall degrading enzymes (lytic enzymes) that degrade the cell 

wall of pathogen (Altomare et al., 1999). 

As an antagonist, Trichoderma may directly kill the pathogen either by antibiosis or by 

mycoparasitism. The simplest technique to test the antagonism between a biocontrol agent and 

fungal plant pathogen is dual culture technique. Attachment of Trichoderma on to the host 

pathogen is followed by a series of degenerative events that promote osmotic imbalances 

triggering cell disruption. Host cell disruption may involve one or more cell wall degrading 

(hydrolytic) enzymes (CWDE) such as cellulases, chitinases, glucanases, proteases and/or 

xylanases and probably also peptaibol antibiotics ( Schirmbock et al, 1994). The combined 

activities of these compounds result in parasitism of the target fungus and dissolution of the cell 

walls. T-harzianum exhibits excellent mycoparasitic activity against Rhizoctonia solani where as T. 

virens relies more on antibiosis against hyphae of this pathogen. 

- 137 -


Antibiosis is the second major mechanism for biocontrol strategy employed by Trichoderma 

in the biocontrol of several fungal phytopathogens. Most Trichoderma strains produce volatile and 

nonvolatile toxic metabolites. Weindeling characterized the lethal principal excreated by strains of 

T. lignorum into the medium as gliotoxin and demonstrated that it was toxic to both Rhizoctonia 

solani and Sclerotinia Americana. At present, Trichoderma is known to produce more than 43 

different types substances having antiobiotic activity such as gliotoxin, gliovirin, glioviridin, viridian, 

alkyl pyrons, isonitrils, polyketides, peptaibols, diketopiperazines, sesquiterpenes and some 

steroids. The production of secondary metabolites by Trichoderma sp. is strain dependent and 

includes anti fungal substances that have been classified into three categories: (i) volatile 

antibiotics, i.e. 6-pentyl-α-pyrone (6 PP) and most of the isocyanide derivatives, (ii) water soluble 

compounds such as heptelidic acid or koningic acid, (iii) peptaibols, that are linear oligopeptides of 

12 to 22 amino acids rich in α – amino isobutyric acid, N-acetylated at the N-terminus and 

containing an amino alcohol at the C-terminus. The production of low molecular weight non polar 

volatile compounds (i.e. 6 PP) results in a high concentration antibiotic in the soil environment that 

has a relatively long distance range of influence on the microbial community (Fig 2). 

Figure 2: Phase 1: the mycoparasite produces high molecular weight compounds that reach the 

host. Phase 2: low molecular weight-degradation products that are released from the 

host cell walls reach the mycoparasite and activate the mycoparasitic gene expression 

cascade.(Schirmbock et al., 1994) 

A unique class of linear hydrophobic polypeptides called peptaibols, is produced by most 

species of Trichoderma. Many peptaibols such as Trichorzianin, trichokindins, harzianins, 

trikoninginus, tichokonins, trichogins etc. exhibit a broad range of bioactivities related to cell 

membrane perturbations (Wiest et al, 2002). They are thought to act on the membrane of the 

target fungus to inhibit membrane associated enzymes involved in cell wall synthesis. The 

apoptosis of the pathogen is associated with the alteration of membrane permeability, loss of 

mitochondrial transmembrane potential, degeneration of cellular organelles, and degeradation of 

DNA along with accumulation of vacuoles in the cytoplasm resulting in the programmed cell death. 

Recently, the antimicrobial peptaibols from Trichoderma pseudokoningii have been reported to 

induce programmed cell death in plant fungal pathogens, Fusarium (Mei Shiet et al, 2012). 

Trichokonins (TK VI), a type of peptaibol from Trichoderma pseudokoningii SMF2, exhibited 

- 138 -


antibiotic activities against plant fungal pathogens (Fusarium oxysporum). 

Fig3: Mrphological changes in TK VI- treated cells of F. oxysporum 

Competition is considered as a classical mechanism of biocontrol that involves competition 

between antagonist and plant pathogens for space air and nutrients. The omni presence of 

Trichoderma in agricultural and natural soils through out the world proves that it is an excellent 

competitor for space and nutritional resources. Neither antibiotic nor mycoparatism is mainly 

involved in biocontrol of seedling disease in cotton but competition is the main mechanism in that 

case. Trichoderma sp. also have the ability to induce systemic and localized resistance in many 

plants and this acts as an indirect biocontrol mechanism. Various plants mono- and dicotyledonous 

species showed increased resistance to pathogen attack when pre-treated with 

Trichoderma (Harman et al, 2004). The pathogenesis related (PR) proteins include anti fungal 

chitinases, glucanases and proteinases and oxidative enzymes such as peroxidases, 

polyphenoloxidases and lipoxygenases. Recently the molecular mechanism of resistance 

induction at gene level in plant by Trichoderma hamatum 382 was studied using high density 

oligonucleotide microarray approach. During interaction of Trichoderma with the plant, different 

classes of metabolites may act as elicitors or resistance introducers ( Lorito, 2007). Trichoderma 

strains produce 3 main classes of compounds that induce resistance in plants: proteins with 

enzymatic activities, avirulence like gene products able to induce defense reaction in plants and 

low molecular weight compounds released from fungal or plant cell walls by the activity of 

Trichoderma enzymes. 

Some pathogens depend upon production of plant cell wall degrading enzymes to infect 

living plants; Botrytis cinerea produces pectinolytic, cutinolytic and cellulolytic enzymes to infect 

living plants. Secondary metabolites or proteolytic enzymes produced by Trichoderma may 

inactivate these pathogens’ enzymes resulting in reduced ability of the pathogen to infect host 

plant. Proteolytic activity of T. viride was claimed to be involved in biocontrol of Sclerotium rolfsii in 

autoclaved soil. Attachment of Trichoderma to the host pathogen is followed by a series of 

degenerating events and degeradation of cell wall of the pathogens by synthesizing various cell 

wall degrading enzymes viz. chitinases, glucanases and proteinases. 

Biological control is of particular interest as a component of integrated pest management 

(IPM) and can best be exploited within the frame work of this management system. Combination of 

the seed/root application of T-harzianum with soil solarization was very effective in management of 

seed and seedling disease of tobacco, brinjal and capsicum in nursery at farmers’ fields. Wilt and 

root rot complex of chickpea, lentil and pigeon pea were successfully managed by integration of T. 

- 139 -


harzianum or T.virens with carboxin. Although, it is fact that use of biocontrol for disease 

management may not totally replace chemicals in near future, but, Judicious use of biocontrol 

agents such as Trichoderma sp. can significantly reduce our dependence on chemical pesticides 

and there by contribute to sustainable agriculture. Not only this the biocontrol agents by replacing 

noxious chemical pesticides and also being more eco friendly in nature, help in clean up 

environment. 

REFERENCES 

• Harman, G.E. 2000. Myths and dogmas of Biocontrol: Changes in the perceptions derived from 

research on Trichoderma harzianum T-22. Plant Dis. 84: 377-393. 

• Cook, R.J. and Baker, K.F. 1983. The nature and practices of biological control of plant 

pathogens. APS Books, St. Paul. MN, U.S.A., pp 599 

• Weindling, R. 1932. Trichoderma lignorum as a parasite of other soil fungi. Phytopathology 22: 

834-845. 

• Harman, G.E. 2002. Trichoderma sp. including, T. harzianum, T.viride, T.koningii, T. hamatum and 

other spp. Deurteromycetes, Moniliales (asexual classification system). Biological 

Control. Cornell University, Geneva, NY. 144-56. 

• 5 . Rifai,M.A. 1969 .A revision of genus Trichoderma. Mycological Papers 116:1-56. . 

• Hayes, C.K., Klemsdal, S., Lorito, M., Di Pietro, A., Peterbauer, C., Nakasa, J.P., Tronsmo, A. and 

Harman, G.E. 1994. Isolation and sequence of an endochitinase –encoding gene 

from a cDNA library of Trichoderma harzianum. Gene 138: 143-148. 

• Hermosa,M.R., Grondona,I.,Iturriaga,E.A., Diaz-Minguez,J.M., Castro,C., Monte,E. and Garcia- 

Acha,I. 2000. Applied and Environmental Microbiology. 66 : 1890-1898. 

• Tewari,L. and Singh,R. 2005. Biological control of sheath blight of rice by Trichoderma harzianum 

using different delivery systems. Indian Phytopath. 58 (1): 35-40. 

• Altomare, C., Norvell, W.A., Bjorkman, T. and Harman, G.E. 1999. Solubilization of phosphates 

and micronutrients by the plant growth promoting biocontrol fungus Trichoderma 

harzianum Rifai 1295-22. Appl. Environ. Microbiol. 65: 2926-2933. 

• Schirmbock, M., Lorito, M., Wang, Y.L., Hayes, C.K., Artisan-Atac, I., Scala, F., Harman, G.E., and 

Kubicek, C.P. 1994. Parallel formation and synergism of hydrolic enzymes and 

peptaibol antibiotics, molecular mechanisms involved in the antagonistic action of 

Trichoderma harzianum against phytopathogenic fungi. Appl. Environ. Microbiol. 

60:4364-4370. 

• Wiest, A., Grezagorski, D., Xu, B., Goulard, C., Rebuffat, S., Ebbole, D. J., Bodo, B., and Kenerly, 

C. 2002. Identification of peptibols from Gliocladium virens and cloning of a peptibol 

synthetase. J. Biol. Chem. 277 (23): 2086-2088. 

• Mei Shi,3 Lei Chen,3 Xiao-Wei Wang, Tian Zhang, Pei-Bao Zhao, Xiao-Yan Song, Cai-Yun Sun, 

Xiu-Lan Chen, Bai-Cheng Zhou and Yu-Zhong Zhang. 2012. Antimicrobial 

peptaibols from Trichoderma pseudokoningii induce programmed cell death in plant 

fungal pathogens. Microbiology (2012), 158, 166–175. 

• Harman,G.E., Howell, C.R., Viterbo,A., Cget,I. and Lorito, M. 2004.Trichoderma sp.- opportunistic, 

avirulent plant symbionts. Nature Reviews Microbiology. 2 (1) : 43-56. 

• Lorito M, Harman GE, Hayes CK, Broadway RM, Tronsmo A, Woo SL, Di Pietro A. 1993. 

Chitinolytic enzymes produced by Trichoderma harzianum: Antifungal activity of 

purified endochitinase and chitobiosidase. Phytopathology 83:302-307. 

- 140 -


Biological Control of Plant Diseases under Different Environments 

Introduction 

V. S. Pundhir and Bhupendra Singh Kharayat 


Traditional methods used to protect crops from diseases have been largely based on the 

use of chemical pesticides. Applications of fungicides and fumigants can have drastic effects on 

the environment and consumer, and are often applied in greater quantities than herbicides and 

insecticides in agricultural production. Chemical methods are not economical in the long run 

because they pollute the atmosphere, damage the environment, leave harmful residues, and can 

lead to the development of resistant strains among the target organisms with repeated use. 

Biological control involves the use of beneficial organisms, their genes, and/or products, 

such as metabolites, that reduce the negative effects of plant pathogens and promote positive 

responses by the plant. To date, a number of BCAs have been registered and are available as 

commercial products, including strains belonging to bacterial genera such as Agrobacterium, 

Pseudomonas, Streptomyces and Bacillus, and fungal genera such as Gliocladium, Trichoderma, 

Ampelomyces, Candida and Coniothyrium. Trichoderma spp. are among the most frequently 

isolated soil fungi and present in plant root ecosystems (Harman et al., 2004). These fungi are 

opportunistic, avirulent plant symbionts, and function as parasites and antagonists of many 

phytopathogenic fungi, thus protecting plants from disease. So far, Trichoderma spp. are among 

the most studied fungal BCAs and commercially marketed as biopesticides, biofertilizers and soil 

amendments (Harman et al., 2004). Depending upon the strain, the use of Trichoderma in 

agriculture can provide numerous advantages: (i) colonization of the rhizosphere by the BCA 

(‘‘rhizosphere competence’’) allowing rapid establishment within the stable microbial communities 

in the rhizosphere; (ii) control of pathogenic and competitive/deleterious microflora by using a 

variety of mechanisms; (iii) improvement of the plant health and (iv) stimulation of root growth 

(Harman et al., 2004). 

The ecological processes determining the successor other wise of biological control are 

complex, with the development of a general theory made difficult by the diversity of target pests 

and biological control organisms. Sustainable biological control of plant pathogens depends on 

efficient exploitation of naturally-occurring micro-organisms. In an ideal crop ecosystem, 

interactions between plant pathogens and their antagonists in the infection court would suppress 

the initiation of infection of the host plant. The complex nature of phyllosphere ecology has, so far, 

militated against the development of successful biocontrol agents (BCA) for foliar plant pathogens. 

Their commercial exploitation in integrated pest or crop management (IPM/ICM) has been 

constrained by the costs of development, governmental policy and supra national directives. 

However, there is optimism concerning future prospects and some demonstrated successes in 

greenhouse cultivation (. The need to predict the outcome of the interactions between a BCA, the 

- 141 -


pathogen, the crop, the resident microflora and the environment has repeatedly been cited as the 

way forward to achieve reproducible biological control. The key to investigating dynamics of a 

biocontrol system is to understand the mechanisms involved in biocontrol, how they interact and 

how they are manifested at different hierarchical levels, from the infection court to the ecosystem 

scale. The principal mechanisms involved include mycoparasitism, antibiosis, competition and 

induced resistance. Additional mechanisms are through hypovirulence mediated through fungal 

viruses, now reported for the first time in Botrytis cinerea and enzymatic interference with 

pathogen pathogenicity enzymes. The characteristics of BCA are such that slight changes in 

external environment could result in drastic changes in the system dynamics and hence biocontrol 

efficacies. This may explain often observed inconsistencies in biocontrol efficacy in practice since 

spatiotemporal environmental heterogeneity is a rule rather than an exception. Implementation of 

biological control is fraught with constraints, and successful application depends on a thorough 

knowledge of the ecology and biology of both the target pest and the biological control agent. 

Although biocontrol has been effective in controlling a range of plant diseases, there are various 

reports in the literature that question its general effectiveness (Cook, 1993). Vasudevan et al. 

(2002) observed that this inconsistency in performance has plagued researchers and their efforts 

to exploit biocontrol agents for commercial use. It generally is acknowledged that disease 

suppression by biological control is the result of complex interactions among the antagonist, the 

pathogen, the host plant and its associated microbial community, and the physical environment 

(Handelsman and Stabb, 1996; Andrews and Harris 2000; Kinkel, 1997; Whipps, 2001). However, 

we are unaware of quantitative studies to synthesize data on the relative efficacy of a range of 

biocontrol agents in suppressing plant disease in relation to biological and application-oriented 

factors. As such, several fundamental questions regarding the level of disease suppression by 

biocontrol agents still remain unanswered. For example, is biological control generally more 

successful for soilborne or for aerial diseases? To what extent is its effectiveness determined by 

overall disease pressure? Is biocontrol really more effective in the greenhouse than in the field, as 

is assumed generally (Paulitz and Bélanger, 2001) ? Are there certain factors related to the 

biology of the pathogen or the biocontrol agent (e.g., fungus versus bacterium, r- versus K- 

selected life history) that help predict success or failure of biological control? And how significant 

and consistent are these effects across a wide range of antagonist–disease combinations? 

Disease suppression, as mediated by biocontrol agents, is the consequence of the interactions 

between the plant, pathogens, and the microbial community. Basic environmental conditions, such 

as temperature, moisture, sunlight, and soil physical and chemical characteristics, can greatly 

affect the physiology of the host plant and subsequent disease development, as well as alter the 

interactions among plant, pathogen, and biocontrol agent in various ways. This is in addition to 

potential direct effects on the pathogen and biocontrol organisms and other soil microbes, and all 

of these effects may influence efficacy of biological control. Other conditions related to the specific 

- 142 -


pathosystem involved, such as the occurrence of different pathogenic races and variability in 

disease resistance and susceptibility among host cultivars, also affect the disease response and 

may influence biological control. 

Biological control under different environments: 

As the plant and plant pathogens adapted to different ecological environments viz. 

phylosphere to rhizosphere, aquatic system (rice-pathosystem) to terrestrial ecosystem, annual to 

perennial tree ecosystem and tropical to subtropical environments. Being biological these 

microorganism have to be applied in accordance with their ecological requirements. 

Biological control in phylosphere 

Kiss (2003) reviewed the ecology, modes of action and biocontrol efficacy of the 

approximately 40 fungal species that have been reported as natural antagonists of powdery 

mildews or have been tested as potential biocontrol agents. Of these, pycnidial fungi belonging to 

the genus Ampelomyces Ces. are the oldest known and the commonest natural antagonists of 

powdery mildews that have been intensively studied in crop protection practice. In addition, the 

interactions between host plants, powdery mildew fungi and Ampelomyces mycoparasites are one 

of the most evident cases of tritrophic relationships in nature, because this relationship is common 

world-wide and takes place exclusively on aerial plant surfaces, thus facilitating its direct 

observation (Kiss, 1998). However, it has received little attention in fungal and plant ecology, 

although it could be used as a model to study the significance of mycoparasitism in the natural 

dynamics of plant parasitic fungi. Some biocontrol fungi have more than one mechanism to 

antagonize their hosts. Trichoderma spp., for example, produces antifungal compounds, act as 

mycoparasites, induce plant defence mechanisms and can stimulate plant growth (Howell, 2003). 

In contrast, Ampelomyces acts directly by invasion and destruction of host cytoplasm. 

Ampelomyces kills the parasitized powdery mildew cells by causing a rapid degeneration of the 

cytoplasm (Hashioka and Nakai, 1980). These mycoparasites suppress both asexual and sexual 

sporulation of the attacked powdery mildew mycelia by colonizing and destroying the 

conidiophores, and the immature ascocarps, respectively. The early stage of Mycoparasitism is 

apparently biotrophic, but the invaded cytoplasm then begins to die and a necrotrophic interaction 

results (Hashioka and Nakai, 1980; Sundheim and Krekling, 1982). 

Biological control in perennial tree ecosystem 

Root rot caused by Heterobasidion annosum sensu lato (Fr.) Bref. is one of the most 

destructive diseases of coniferous trees in the Northern Hemisphere. The annual economic losses 

caused by this fungus in Europe are estimated to at least 790 million €. The main route of infection 

for H. annosum s.l. is by basidiospores germinating on the stump surface after tree felling during 

summer periods. Thereafter the fungus invades neighboring healthy trees via root contact 

(Redfern and Stenlid, 1998). Currently, Phlebiopsis gigantea (Fr.) Jül., a common saprotrophic 

wood-decay basidiomycete and a highly competitive primary colonizer on conifer wood, is used as 

- 143 -


an effective biological control agent against Heterobasidion in many European countries 

(Korhonen et al., 1993). One of the most commonly used formulas of P. gigantea is registered as 

Rotstop. A biocontrol method to reduce H. annosum s.l. infection is to apply the wood degrading 

fungus Phlebiopsis gigantea in a spore solution (Rotstop) directly on the freshly cut stumps 

immediately after cutting. 

Biological control in rhizospheric disease 

Wilt 

The use of biocontrol agents to control Fusarium wilt has been reported for many crops 

including tomato, cucumber, melon, strawberry, banana and carnation. Several reports have 

previously demonstrated the successful use different species of Trichoderma, Pseudomonas, 

Streptomyces, non pathogenic Fusarium (npFo) of both rhizospheric and endophytic in nature 

against Fusarium wilt disease under both glass house and field conditions (Alabouvette et al. 

1993; Getha et al. 2005). Several reports indicate that Trichoderma species can effectively 

suppress Fusarium wilt pathogens (Sivan and Chet, 1986). Georgios et al. (2007) have been used 

two known Pseudomonas biocontrol strains separately and in combination to assess their 

antagonistic effectiveness against F. oxysporum f. sp. niveum in pot experiments. P. chlororaphis 

PCL1391 significantly reduced disease severity. P. fl uorescens WCS365 was less effective in 

disease suppression, while a combination of the two bacteria had intermediate effects. He also 

noted that biological control of Fusarium wilt with P. chlororaphis offers a potentially useful tool in 

an integrated pest management program to control Fusarium wilt of watermelon. 

Root rot and Dampig-off 

Damping-off and root rot on greenhouse cucumbers, mainly caused by a number of 

Pythium spp., including P. aphanidermatum, P. ultimum and P. irregular, are recurring problems 

for growers. Biological control of damping-off and root rot of cucumber caused by various Pythium 

spp. have identified nonpathogenic (mycoparasitic) Pythium spp. and a number of bacterial 

antagonists, primarily Pseudomonas spp. (Paulitz and Bélanger 2001) and Bacillus subtilis 

(Ehrenberg) Cohn as potential biocontrol agents, which were shown to significantly reduce disease 

severity. In addition, the biocontrol agents S. griseoviridis and T. harzianum in Mycostop and 

Rootshield, respectively, are reported to be effective against damping-off and root rot diseases 

caused by Pythium spp. (Paulitz and Bélanger 2001). 

Biological control of plant parasitic nematodes 

Biological control of nematodes is the use of microbial agents such as bacteria and fungi 

that reduce nematode population by their antagonistic behaviour. Fungi continuously destroy 

nematodes in virtually all soils because of their constant association with nematodes in the 

rhizosphere. Pasteuria penetrans has been the subject of intensive study as a promising biological 

control agent of nematodes. A large number of nematophagous fungi are known to trap or prey on 

nematodes, but the most imporant genera include Arthrobotrys, Monacrosporium, Nematophthora, 

- 144 -


Hirsutella, Verticillium and Paecilomyces. Application of some of these fungi in vegetable crops 

has given interesting results. Integrated nematode management can be realized by variety of 

techniques including predators and parasites, genetic resistance of host, soil amendment with 

organic matter and other cultural practices. Few commercial preparations of these fungi are also 

available in the market. 

Non-target effects of fungi used to biologically control plant diseases 

While effective in the control of plant diseases, these mechanisms may pose risks to nontarget 

species including mycorrhizal and saprophytic fungi, soil bacteria, plants, insects, aquatic 

and terrestrial animals, and humans. Non-target effects including mycoparasitism of mycorrhizae, 

reduction in plant root colonisation by mycorrhizal fungi, disorders in commercial mushrooms and 

nodulation by Rhizobium spp., and changes in plant growth have been associated with fungal 

biological control agents, such as Trichoderma spp. Also, the genera Trichoderma and 

Gliocladium have been linked to respiratory disorders and shellfish toxicity in humans, 

respectively. Biological control agents, such as Pythium oligandrum, Talaromyces flavus, 

Coniothyrium minitans and Ampelomyces quisqualis have modes of action which may pose risks 

to non-target fungi, bacteria, plants and animals. There is need for future research into ecological 

impacts associated with the release of any biological agent and methods of determining possible 

non-target effects. Adequate monitoring and the use of molecular techniques to identify and follow 

the movement of biological control agents are needed to examine and mitigate negative biological 

impacts (Theresa and Boland, 2003). 

Future Prospects 

One of the biggest ecological challenges facing microbiologists and plant pathologists in 

the near future is the development of environmentally friendly alternatives to the extensive use of 

chemical pesticides for combating crop diseases. The use of beneficial microorganisms 

(biopesticides) is considered one of the most promising methods for more rational and safe cropmanagement 

practices. In the short term, the technology already exists to directly identify 

biocontrol agents active against target pathogens, to select strains with an affinity for particular 

crops or cultivars, to engineer strains for greater efficacy and reliability, and to develop and exploit 

soils naturally suppressive to particular pathogens. For specific pathosystems, how does the 

environment influence the asymptotic limit to biological control? Can asymptotic limits to biocontrol 

be shifted by new, mixed, or altered technologies? 

REFERENCES 

• Alabouvette, C.; Lemanceau, P. and Steinberg, C.1993. Recent advances in the biological control 

of Fusarium wilts. Pesticides Science. 37:365–373. 

• Andrews, J. H. and Harris, R. F. 2000. The ecology and biogeography of microorganisms on plant 

surfaces. Annu. Rev. Phytopathol. 38:145-180. 

• Cook, R. J. 1993. Making greater use of introduced microorganisms for biological control of plant 

pathogens. Annu. Rev. Phytopathol. 31:53-80. 

• Georgios T.T.; Anastasia, L. and Katina T.K. 2007. Reduction of Fusarium wilt in watermelon by 

- 145 -


Pseudomonas chlororaphis PCL1391 and P. fl uorescens WCS365. Phytopathol. 

Mediterr. 46: 320–323 

• Getha K.; Vikineswary, S.; Wong, W.; Seki, T.; Ward, A. and Goodfellow, M. 2005. Evaluation of 

Streptomyces sp. strain G10 for suppression of Fusarium wilt and rhizosphere 

colonization in pot grown banana plantlets. Journal of Industrial Microbiology and 

Biotechnology. 32: 24-32. 

• Handelsman, J. and Stabb, E. V. 1996. Biocontrol of soilborne plant pathogens. Plant Cell 

8:1855-1869. 

• Hashioka, Y. and Nakai, Y. 1980. Ultrastructure of pycnidial development and mycoparasitism of 

Ampelomyces quisqualis parasitic on Erysiphales. Transactions of the Mycological 

Society of Japan 21, 329-338. 

• Howell, C.R. 2003. Mechanisms employed by Trichoderma species in the biological control of 

plant diseases: the history and evolution of current concepts. Plant Disease. 87: 4- 

10. 

• Kinkel, L. L. 1997. Microbial population dynamics on leaves. Annu. Rev. Phytopathol. 35:327-347. 

• Kiss, L. 2003. A review of fungal antagonists of powdery mildews and their potential as biocontrol 

agents. Pest Management Science. 59: 475-483. 

• Loliam, B.; Morinaga, T. and Chaiyanan S. 2012. Biocontrol of Phytophthora infestans, fungal 

pathogen of seedling damping off disease in economic plant nursery. Hindawi 

Publishing Corporation Psyche. Volume 2012, Article ID 324317, 6 pp. 

doi:10.1155/2012/324317 

• Paulitz, T. C. and Bélanger, R. R. 2001. Biological control in greenhouse systems. Annu. Rev. 

Phytopathol. 39:103-133. 

• Sikora, R.A. 1992. Management of the antagonistic potential in agricultural ecosystems for the 

biological control of plant-parasitic nematodes. Ann. Rev. Phytopathol. 30: 245-270. 

• Sivan, A. and Chet, I.1986. Biological control of Fusarium spp. in cotton, wheat and muskmelon by 

Trichoderma harzianum. J.Phytopathol. 116: 39–47. 

• Stirling, G.R. 1991. Biological control of plant-parasitic nematodes. Wallingford, UK, CAB 

International. 282 pp. 

• Sundheim, L. and Krekling, T. 1982. Host-parasite relationships of the hyperparasite 

Ampelomyces quisqualis and its powdery mildew host Sphaerotheca fuliginea . 

Journal of Phytopathology.104:202-210. 

• Theresa, A.B. and Boland, G.J. 2003. A review of the non-target effects of fungi used to 

biologically control plant diseases. Agriculture, Ecosystems and Environment.100:3- 

16. 

• Vasudevan, P.; Kavitha, S.; Priyadarisini, V. B.; Babujee, L. and Gnanamanickam, S. S. 2002. 

Biological control of rice diseases. in: Biological Control of Crop Diseases. S. S. 

Gnanamanickam, ed. Marcel Dekker, New York. p387-420. 

• Whipps, J. M. 2001. Microbial interactions and biocontrol in the rhizosphere. J. Exp. Bot. 52:487- 

511. 

- 146 -

Introduction 


Microbes and Soil Quality 

Kiran P. Raverkar 


Soil is a very valuable natural resource and wonderful gift of nature to the human being 

which performs infinite functions. The agriculture related main ecological functions fulfilled through 

soil include i) production of biomass ii) various filtering, buffering and transforming actions, and iii) 

a niche for biological habitat and gene reserve. It is critical for the maintenance of any ecosystem; 

therefore, the well being of soil is pivotal for the sustenance and survival of the life on the earth. As 

per the Soil Science Society of America “soil quality is the capacity of a specific kind of soil to 

function within natural or managed ecosystem boundaries to sustain plant and animal productivity, 

maintain or enhance water and air quality, and support human health and habitation”. The soil 

quality dictates the four main horizons of the life which are interrelated (Fig. 1). 

Soil Productivity 

Human/Animal 

Health 

Soil Quality 

Food quality/ 

safety 

Environmental 

quality 

Fig.1: Horizons of the life influenced by soil quality 

The physical, chemical and biological are the main components of soil quality. The physical 

as well as chemical properties are governed by the microbial world of soil. The biological 

properties which can be measured as indices of the soil quality mainly include potentially 

mineralizable N, microbial biomass, soil respiration, different enzymatic activities etc. Soil microbial 

biomass indicates the soil microbial population whereas the soil respiration tells about to the 

metabolic activity. Soil is a reservoir of most of the enzymes of microbial as well as plant origin. 

Some enzymes such as dehydrogenases are of general importance whereas phosphatases 

indicate the specific activity of microorganisms. Hoffmann and Seegerer (1950) was the first to 

propose the use of enzymes as an index of the fertility status of soil. The integrative activity of 

number of soil enzymes has been proposed to predict soil fertility vis-à-vis soil quality. This 

approach reflects the release of nutrients during organic matter turnover as well as relative 

availability of inorganic nutrients over the estimation of activity of single enzyme. By employing the 

- 147 -


cluster analysis Zhou and Co-workers (1983) grouped Chinese soils into four fertility classes. Qui 

et al (1981) also reported a positive correlation between enzyme activities and fertility levels. 

During organic matter decomposition the activities of various enzymes releases the specific plant 

nutrients and thus their activity correlates with the soil fertility status. 

Microbes and their role 

The microorganisms present underneath and on the surface layers of soil plays a pivotal 

role in sustaining the soil fertility and plant health for crop production due to their intrinsic/ acquired 

abilities to perform an array of roles such as soil humus formation, biological control of pests, 

growth promotions, soil tilth and structure (Lynch and Bragg, 1985). Belowground diversity 

encompasses a spectrum of microbes including bacteria, fungi, actinomycetes, algae and 

protozoa. The plants secrete various carbon rich compounds in the rhizosphere which are used as 

source of carbon by the microbial community for its maintenance and to function. The plants are 

dependent for their nutrition on the abilities of the microorganisms to make the various nutrients 

available e.g. nitrogen, phosphorus, iron etc. Out of the myriad population some microorganism 

forms the close association with plants that could be beneficial, neutral or detrimental to the plant. 

Ecosystems in nature are generally in equilibrium state which supports the sustainable 

biomass production for human use maintaining the quality of natural base. However, the 

interventions introduced for enhanced agricultural production results in disturbed ecosystem vis-àvis 

deteriorated quality of natural base. The “green revolution” in India was fuelled through the use 

of plant genotypes highly responsive to chemical sources of nutrients, especially nitrogen. The 

long term sustainability of agricultural ecosystems, which are dependent on the use of chemical 

fertilizers and modern intensive practices of cultivation, maintaining the surrounding environment 

intact is under question since recent past. 

Human population in the world is flattening over the years and would reach to 9 billion mark 

by the year 2020. The challenge of meeting the need for food of exploding population over the 

time could only be achieved through intensification of the agriculture using modern technologies 

(Borlogue and Dowswell, 1994), considering the sustainability aspects. The sustainable agriculture 

addresses the judicious management of varying natural resources satisfying the changing human 

needs while maintaining/ improving the quality of natural resource base and environment. Among 

the various natural resources soil is the prime and thus it becomes imperative to maintain/improve 

the health of it. If the soil is sick it reflects immediately on the tiny creatures of the soil i.e. microbes 

and thus soil biological properties would indicate the wellbeing of the soil. Estimation of group of 

soil properties, thus, to understand the impact of various management practices on soil health is a 

good and sound proposal. The various physical, chemical and biological soil quality indicators are 

listed in Table 1. 

- 148 -


Table 1. Physical, chemical and biological soil quality indicators 

Chemical indicators Physical indicators Biological indicators 

Cation exchange Aggregate stability Microbial biomass 

capacity 

Bulk density 

Biomass C/N 

pH 

Aeration 

Potentially mineralizable 

Electrical conductivity 

Contaminants presence, 

Hydraulic 

conductivity 

nitrogen 

Soil respiration 

concentration, mobility Consistence 

Soil enzymes (Phosphatase, 

etc. 

Total N & P etc. 

WHC 

dehydrogenase, 

arylsulphatase) 

Organic matter 

Soil Quality components 

Soil quality comprises inherent as well as dynamic soil quality parameters. Inherent soil 

quality defines the inherent capacity of a soil for crop growth. It depends on the properties which 

are static, changing little over short time frame (years to decade) as developed as the product of 

soil formation. While dynamic soil quality is based on the properties that change over short time 

frame (years to decade) and influenced by land use management and agronomic practices. 

Major services provided by soil 

Soil function in many ways and provides various services for keeping the environment 

sustainable for the life on earth. The major services provided by soil are: 

• Transformation of carbon through decomposition of plant residues including SOM 

◦ Essential ecosystem function 

◦ Driver of nutrient cycling 

◦ Also supports detoxification and 

◦ Waste disposal service 

◦ C-sequestration: role in regulating emission of GHG e.g. CO 2 and CH 4 

• Cycling of nutrients: N, P, K including N2O emissions 

• Maintenance of structure and fabric of the soil 

◦ Soil aggregation 

◦ Particle transport 

◦ Formation of biostructures 

◦ Pore networks 

• Biological regulation of soil population 

Soil is composed of solid, liquid and gaseous phases and is dominated by solid phase. 

However for the sustenance of soil health the balance between these three phase is very 

important. 

- 149 -


Microorganisms: key functions in soil 

In top soil biological components occupy


compared (Karlen et al, 2000). For monitoring the soil health policy relevant end points are very 

important. The end points should be pragmatic which can provide logical categories fro regulatory 

decisions and should be integrated for indicators that are ecologically related. An end point matrix 

has been suggested (Fig. 2), which provides a comprehensive and effective assessment of soil 

health when integrated together (Nielsen and Winding, 2002). 

Pressure on soil health 

Climate, natural events, urbanisation, 

agriculture, forestry, waste disposal 

etc. 

Atmospheric 

balance 

Soil health 

Plant health 

Animal 

health 

Human 

health 

Soil microbial 

community 

health 

Fig. 2: Policyrelevant 

end points of soil health 

Leaching to gr. 

Water 

Surface run-off 

monitoring 

Driving force-Pressure-State-Impact-Response (DPSIR) assessment 

Soil 

ecosystem 

health 

Relevant indicators of specific end points have been identified based on DPSIR 

assessment framework, that has been developed primarily for environmental issues. The DPSIR 

framework can be employed for assessment of soil health provided the indicators for each of the 

PSI-elements developed (Huber et ai, 2001). The DPSIR assessment framework applied to soil is 

depicted in Fig.3. 

- 151 -


Reform of environmental policy 

Changing mgnt. practices 

Responses 

Changes in soil functions 

Changes in crop yields 

Loss of biodiversity 

Impacts 

Agriculture 

Driving force 

Over grazing 

Over fertilization 

Intensive cropping 

Wastes recycled to land 

Pressures 

State 

Contamination 

Nutrient leaching to 

ground water 

Fig.3. The DPSIR assessment framework for soil 

Criteria specific to soil health indicators 

Doran and Safley (1997) have listed certain criteria for soil health indicators. The soil health 

indicators should be: 

linked and/or correlated with ecosystem processes 

• integrated with soil physical, chemical, and biological properties 

• selected relative to ease of performance and cost effectiveness 

• responsive to variations in management and climate at an appropriate time scale 

• compatible with existing soil data bases when possible 

Since the soil fulfills the diversified functions through various services to the planet earth it 

is difficult to identify and rely on one single property for assessment of soil health. Instead of 

evaluating the psoil health based on single parameter(s) independently it is wise to employ the 

DPSIR concept characterizing the end points through several soil ecosystem parameters (Table 

3). 

- 152 -


Table 3. End points for monitoring soil health through soil ecosystem parameters 

End point 

Atmospheric balance 

Soil ecosystem health 

Soil microbial community health 

Leaching to groundwater or 

surface run-off 

Plant health 

Animal health 

Human health 

Soil ecosystem parameter 

C-cycling 

Biodiversity 

C-cycling 

N-cycling 

Microbial biomass 

Microbial activity 

Key species 

Biodiversity 

C- cycling 



Bioavailability 

N-cycling 


N-cycling 

Key species 



Key species 


Microbial indicators of soil health 

Microbial indicators cover a diverse set of microbial measurements due to multifunctional 

properties of microbial communities in soil ecosystem. Various microbial indicators which can be 

monitored in respect of the soil ecosystem parameters along with the methods available are given 

in Table 4. 

Table 4. List of microbial indicators for soil health monitoring 

Soil ecosystem Microbial indicator 

parameter 

Biodiversity Genetic diversity Functional 

diversity Marker lipids 

Ready-to-use 

methods 

PCR-DGGE BIOLOGTM 

PLFA 

C-cycling 

Soil respiration 

Metabolic quotient (qCO2) 

Decomposition of organic matter 

Soil enzyme activity Methane 

oxidation 

Methanotrophs 

CO 2 -production or O 2 -consumption 

C resp /C biomass 

Litterbags 

Enzyme assays Methane 

measurements 

MPN 

PLFA 

- 153 -


N-cycling 

N-mineralisation Nitrification 

Denitrification 

N-fixation: Rhizobium 

N-fixation: Cyanobacteria 

Microbial biomass Microbial biomass: Direct 

methods 

Microbial biomass: Indirect 

methods 

Microbial quotient 

Fungi 


Fungal-bacterial ratio Protozoa 

Bacterial DNA synthesis 

Bacterial protein synthesis 

RNA measurements 

Community growth physiology 

Bacteriophages 

NH 4 + -accumulation 

NH 4 + -oxidation assay 

Acetylene inhibition 

assay 

Pot test 

MPN 

Nitrogenase activity 

Microscopy 

PLFA 

CFI,CFE 

SIR 

C micro / C org 

PLFA 

Ergosterol 

PLFA 

MPN 

Thymidine incorporation 

Leucine incorporation 

CO 2 -production or 

O 2 -consumption 

Key species 

Mycorrhiza 

Human pathogens 

Microscopy 

Pot test 

Selective plating 


Suppressive soil 

Biosensor bacteria 

Plasmid-containing bacteria 

Antibiotic-resistant bacteria 

Incidence and expression of 

catabolic 

genes 

Pot test 

Remedios TM , Microtox R 

Gel electrophoresis 

Selective growth 

Selective growth 

Epilogue 

Microbes and their activities are undisposable component for the quality maintenance/ 

improvement of soil. The multifaceted functions played by the microorganisms contributes directly 

as well as indirectly to the soil quality. Microbes helps in growing the plants healthy i.e. free of 

diseases as well as nourishing it with the essential nutrients through various activities. This is 

achieved through managing organic matter and enhancing soil life including microorganisms, and 

optimizing nutrient availability by green manure, composts and other biofertilizers, including the 

use of nitrogen fixing crops. To monitor the changes occurring as an impact of various 

management practices in agriculture, microbial indicators provide a very effective tool for 

discriminating the positive/ negative impact on soil health. However for monitoring the soil health in 

a real sense it is pertinent to consider the end point processes dictated by the soil ecosystem 

- 154 -


parameters. The DPSIR framework would be more realistic for evaluating and monitoring the soil 

health for formation of the effective policies for the maintenance of soil health for sustaining the life 

on the earth. 

REFERENCES 

• Borlogue, N. E. and Dowswell, C. R. (1994). Key note lecture. Suppl. Trans. Of 15th World 

Congress of Soils Science. p. 15. 

• Doran, J.W. and Safley, M. (1997). Defining and assessing soil health and sustainable 

productivity. In : Biological Indicators of Soil Health. Pankhurst, C.E., Doube, B.M., 

and Gupta, V.V.S.R. (eds.). CAB International, pp. 1-28. 

• Hoffman, E. and Seegerer, A. (1950). Biochem. Z. 321 :97. 

• Huber, S., Syed, B., Freudenschuss, A., Ernstsen, V., and Loveland, P. (2001). Proposal for a 

European soil monitoring and assessment framework. Technical report no. 61, 

European Environment Agency, Copenhagen, Denmark 

• Karlen, D. L. and Andrews, S. S. (2000). The soil quality concept: A tool for evaluating 

sustainability. In: Soil Stresses, Quality and Care; DIAS Report Plant Production 

no.38, Elmholt, S., Stenberg, B., Grønlund, A. and Nuutinen, V. (eds.), Danish 

Institute of Agricultural Sciences, Tjele, Denmark, p.15-26. 

• Lynch, J. M. and Bragg, E. (1985). Microorganisms and soil aggregate stability. Adv. Soil Sci. 2 : 

133. 

• Nielsen, M.N. and Winding ,A. (2002). Microorganisms as indicators of soil health. Ministry of the 

Environment, national Envirojnmental Research Institute. Pp. 84. 

• Qui, F. Q., Zhou, L. K., Chen, E. F.,Ding, Q. T., Zhang, A. M. and Dang, L.C. (1981). Acta Pedol. 

Sin. 18 : 244. 

• Zhou, L. K., Zhang, Z. M. and Cao, C. M. (1983). Acta Pedol. Sin. 20 : 413. 

- 155 -


Suppressive Soils in Plant Disease Management 

Krishna Pratap Singh 


Soil is a complex mix of organic and inorganic matter that includes thousands of different 

species, the vast majority of which are still undescribed. Some of the organisms are pests which 

cause significant crop losses while others perform ‘environmental services’ such as biological 

control of pests, aeration, drainage, nutrient and water cycle. Disease suppressive soils have been 

recognized for over 100 years and the mechanisms by which disease suppression is brought 

about has been the subject of study for nearly four decades. Disease suppressive soils are defined 

by Cook and Baker (1983) as soils in which the pathogen does not establish or persist, the 

pathogen establishes but causes no damage or the pathogen causes some disease damage, but 

the disease becomes progressively less severe even though the pathogen persists in soil. The 

mechanism of suppression of soil includes antibiosis, competition, parasitism and predation. 

Chemical and physical attributes of soil, including pH, organic matter and clay content, can 

operate in the suppression of plant diseases directly or indirectly through their impact on soil 

microbial activity. 

Disease Suppressive Soils 

A disease suppressive soil is one in which the level of disease that develops on plants 

grown in that soil is less than that which develops on plants grown in other soils under similar 

conditions. However, almost all soils have some disease suppressive properties, so the 

phenomenon of disease suppressive soil should be thought of on a continuum of low to high levels 

of suppression, rather than thinking of soils as being either disease suppressive or conducive. In 

many cases the disease suppressive nature of a soil is the result of the presence and activity of 

the microorganisms in the soil. Bacteria, fungi, and soilborne fauna can all act to change the 

suppressiveness of a soil. 

Soil is considered suppressive when, in spite of favorable conditions for disease to occur, a 

pathogen either cannot become established, establishes but produces no disease, or establishes 

and produces disease for a short time and then declines. Suppressiveness is linked to the types 

and numbers of soil organisms, fertility level, and nature of the soil itself (drainage and texture). 

The mechanisms by which disease organisms are suppressed in these soils include induced 

resistance, direct parasitism (one organism consuming another), nutrient competition, and direct 

inhibition through antibiotics secreted by beneficial organisms. Additionally, the response of plants 

growing in the soil contributes to suppressiveness. This is known as “induced resistance” and 

occurs when the rhizosphere (soil around plant roots) is inoculated with a weakly virulent 

pathogen. After being challenged by the weak pathogen, the plant develops the capacity for future 

effective response to a more virulent pathogen (Sullivan, 2004). There are numerous terms (Table 

1) that have been used to describe the apparent properties of such soils. 

- 156 -


Table 1. Favourable/ Unfavourable terms used to describe for disease development 

Favourable for disease development 

Conducive 

Non-competitive 

Non-decline 

Non-immune 

Non-impeditive 

Non-inhibitory 

Non-resistant (Susceptible) 

Receptive 

Short life 

Sterile 

Unfavourable for disease development 

Suppressive 

Competitive 

Decline 

Immune 

Impeditive 

Inhibitory 

Resistant 

Antagonistic 

Long life 

Biologically buffered, Fungistatic, Disease 

suppressive, Pathogen suppressive 

Specific and General Suppression 

Historically, suppressiveness to soilborne diseases in field soils has been divided into two 

major categories: general and specific. Specific suppression results from one organism directly 

suppressing a known pathogen. These are cases where a biological control agent is introduced 

into the soil for the specific purpose of reducing disease incidence. General suppression is the 

result of a high biodiversity of microbial populations that creates conditions unfavorable for plant 

diseases to develop. A good example of specific suppression is provided by a strategy used to 

control one of the organisms that cause damping off—Rhizoctonia solani. Where present under 

cool temperatures and wet soil conditions, Rhizoctonia kills young seedlings. The beneficial fungus 

Trichoderma locates Rhizoctonia through a chemical released by the pathogen, then attacks it. 

Beneficial fungal strands (hyphae) entangle the pathogen and release enzymes that dehydrate 

Rhizoctonia cells, eventually killing them. 

In one case soil organic matter case, management had an unexpected effect on take all 

suppression. Organically managed soils had lower levels of antibiotic producing Pseudomonas 

fluorescens, but still had low levels of disease even with the presence of the pathogen. 

Conventionally managed soils had high levels of antibiotic producing P. fluorescens, but also had 

high disease. The reality of suppressive soils is much more complex than it is usually presented 

when you take into account soil organic matter characteristics and the overall activity of the soil 

microbiota. So even in cases with well studied and extensively documented biocontrol organisms, 

there are aspects of the system that we are just beginning to understand. 

According to Cook and Baker (1983): General suppression is related to the total amount of 

- 157 -


microbiological activity at a time critical to the pathogen. A particularly critical time is during 

propagule germination and pre-penetration growth in the host rhizosphere. The kind of active soil 

microorganisms during this period are probably less important than the total active microbial 

biomass, which competes for the pathogen for carbon and energy in some cases and for nitrogen 

in other cases, and possibly causes inhibition through more direct forms of antagonism. In a 

sense, general suppression is the equivalent of a high degree of soil fungistasis. No one 

microorganism or specific group of microorganisms is responsible by itself for general 

suppression. 

Specific suppression operates against a background of general suppression but is more 

qualitative, owing to more specific effects of individual or select groups of microorganisms 

antagonistic to the pathogen during some stage in its life cycle 

Suppression: “it depends”: Variability of suppression with composted materials is extremely 

high. Scientists don’t understand enough at this point to predict if a batch of compost will suppress 

a certain disease on a certain crop which is a major obstacle to using these materials effectively in 

farming. Many of the studies that test multiple batches of compost in a variety of pathosystems 

come up with the somewhat unsatisfying conclusion that “sometimes it works, sometimes it 

doesn’t and we’re not totally sure why”. 

Variability of suppression: Compiling the results of over 400 scientific papers shows that the 

variability of suppression increases with the number of pathogens tested in the study. So that even 

if a particular batch of compost is consistently suppressive towards one plant pathogen, it is likely 

to have a range of effects on other pathogens. This variability is of great relevance to growers 

because very rarely is there only one pathogen causing a problem in a specific production system. 

Real world complications: Testing compost‐ based materials in the field can be complicated by 

the fact that multiple pathogens are naturally present. In this on‐ farm trial of aerated liquid 

compost extracts conducted by the Rodale Institute, the authors found that treatment with the 

extracts significantly controlled some of the pathogens while actually exacerbating the symptoms 

caused by other pathogens. 

Dangerous Assumption: All composts and cover crops that suppress disease do so by reducing 

the amount of pathogen present in the soil. One reason for the variability of suppression seen with 

composts among a range of pathogens is that different mechanisms are involved in the 

suppression of different types of pathogens. 

Suppression index: Specific measurements are often associated with suppression as seen in this 

“suppression index”. Positive numbers on the index indicate that a high value of a measurement 

like microbial activity or total bacterial cell counts positively correlates with suppression and vice 

versa. When all available scientific data on all pathosystems is combined several indicators stand 

- 158 -


out as being consistently associated with suppression. 

However, when you look at the suppression index for different types of pathogens the 

variability becomes more apparent. For example high levels of FDA hydrolysis (a measure of 

microbial activity) is positively correlated with suppression of Pythium spp., but negatively 

correlated with suppression of Rhizoctonia spp. This variability of reliable indicators depending on 

the type of is one of the reasons suppression is so difficult to predict. 

History of disease suppression research: 

The existence of soils which are unfit for the development of certain diseases has been 

- 159 -


known for a long time without attempts to understand the reasons such as the physical or chemical 

properties of the soil, cultural practices or genuine suppression due to natural biological control. 

Mac Millan (1919) describe earlier on disease suppression in the presence of the pathogen. He 

observed that Fusarium blight of potatoes was severe in San Luis Valley and Greeley District but 

that the disease had subsided in the latter area. It was generally assumed that the populations of 

the pathogen declined under alfafa, however, Mac Millan observed that in some locations 

Fusarium blight was severe after 9 years of alfalfa, while in others only one years was sufficient to 

get good control. Thus, he concluded that suppression had occurred in the presence of the 

pathogen. By 1934, certain soil types in Wisconsin were recognized as those in which the pea wilt 

organism established itself quickly and others in which the organism developed slowly and wilt 

occurred seldom or not at all. Menzies introduced the concept of “suppressive soils” with his work 

on the relationship of soil type to Streptomyces scab of potato, in California. Since then many 

research paper/ articles have appeared describing the complex nature of disease suppression in 

soil. However, the subject of “Suppressive soil” received considerable fillip from the publication of 

a book “Biological control of plant pathogens” by Baker and Cook, in 1974. The history has been 

known for a long time to suppressed in certain soils are, 

o Late 1800s: suppressive soils documented [Huber & Schneider, 1982] 

o 1930s-1940s: Link made between composts and soil health [Howard, 1943] 

o 1956: Biological nature of suppression documented [Menzics 1959] 

o 1970s-1980s: Extensive work done on suppressive composts [Hoitink & Kuter, 1986, 

Weltzein, 1989] 

There is a vast literature on the biological control of soil-borne pathogens, but for this 

article the goal is to examine examples of biological suppression of soil-borne plant pathogens. 

The pathogens reported to have been suppressed in certain soils are listed in Table 2. 

Table 2. Examples of Disease- Suppressive Soils 

Pathogens Disease(s) caused Pathogens Disease(s) caused 

Armillaria mellea Root rot of conifers Gaeumannomyces Take-all of wheat 

graminis 

Cephalosporium Stripe of wheat Olpidium brassicae Lettuce 

graminearum 

Didymella lycopersici Stem rot of tomato Phomopsis scleroides Rot of cucurbits 

Fusarium avenaceum Root rot of lentils Phytophthora 

cinnamomi 

Root rots of various 

crops 

F. oxysporum f.sp. Wilt of sweet potatoes Poria weirii Root rot of conifers 

batatas 

F. oxysporum f.sp. Wilt of banana Pseudocercosporella Root rot of cereals 

cubense 

herpotrichoides 

F. oxysporum f.sp. Wilt of cucurbits Pseudomonas Soft rots 

cucumerinum 

solanacearum 

F. oxysporum f.sp. Wilt of cyclamen Pythium 

Root rot of radish 

cyclaminis 

aphanidermatum 

- 160 -


F. oxysporum f.sp. Wilt of carnation Pythium ultimum Root rots 

dianthi 

F. oxysporum f.sp. lini Wilt of flax Pythium spp. Root rots 

F. oxysporum f.sp. Wilt of tomato Rhizoctonia solani Root rots of many 

lycopersici 

crops 

F. oxysporum f.sp. Wilt of melon Sclerotium rolfsii Root rot of tomato 

melonis 

F. oxysporum f.sp. Wilt of pea S. cepivorum Wilt of onion 

pisi 

F. oxysporum f.sp. Wilt of beans Streptomyces scabies Scab of potatoes 

phaseoli 

F. oxysporum f.sp. Wilt of radish 

Verticillium albo-atrum Wilt of potatoes 

raphani 

F. udum Wilt of pigeonpea Heterodera avenae Cereal cyst nematode 

F. solani Root rot of beans 

Physical and chemical characteristics of suppressive soil: 

Soils are composed of varying proportions of solids, liquids and gases. The relative 

amounts of liquids and gases depend upon how tightly the solid particles are packed together. 

Depth, texture, structure, porosity, and consistency are important physical properties. They 

influence rooting depth, aeration, water movement and chemical and biological activities. Physical 

factors that influence microorganisms include moisture, temperature, aeration, and the mechanical 

strength of the soil. Texture refers to the particle sizes of the soil, such as, sand, silt and clay. It 

affects aeration, water retention and root movement. The arrangement of the individual particles 

into larger units determines soil structure. Clay and humus adhere to form units of soil called peds. 

Soil porosity refers to that part of the soil that contains air and water and the relative proportion of 

each varies with the wetness or dryness of the soil. Soil chemical properties refer the inorganic 

and organic constituents. Soil organic matter, cation exchange capacity, pH and minerals, soluble 

or insoluble, all constitute the chemical properties of the soil. The biological activity is strongly 

affected by the chemistry of the microhabitat (Chaube, 1989) 

Burke (1965) was not able “to transfer the rot suppressive properties of the resistant soil to 

others by transfer of microorganisms” even with the addition of nutritive substances or by 

autoclaving the receptor soil. This “suggests that rot suppression depends upon the predominance 

of both physical and microbiological components of the resistant soil and that neither 

component alone is sufficient to produce the effect”. Examples of suppressive and or conducive 

soils influenced by physical and chemical properties of soil are summarized in the Table 3. The 

carpogenic germination of sclerotia of Sclerotinia sclerotiorum in soil samples collected from 

different places of Uttar Predesh, India has been studied by Singh et.al. 1991 and 1995. The 

percentage germination increased with increasing amounts of sand in the soil samples but was 

reduced in the soil that contained high concentrations of Na + , Ca 2+ , Cl - and So 2- 4 . Similar 

carpogenic germination was observed in the soil that had very low amounts of Mg 2+ and HCO - 3 . 

There was a reduction in carpogenic germination in those soils which had more organic carbon. 

- 161 -


There was no uniform effect on pH on sclerotial germination but the pH of all the soil samples was 

above 7. Physico-chemical properties, ion-exchange capacity and soil nutrient status influenced 

apothecial germination of sclerotia of S. sclerotiorum. The cation exchange capacity of different 

soil samples indicates that the soil sample (Rajapur Muksudan) showing maximum cation 

exchange capacity also shows minimum carpogenic germination. This is because of the fact that 

the soils having more cation exchange capacity release more nutrients for the growth of plants, but 

carpogenic germination of sclerotia is known to be favoured on the medium that contains least 

nutrients and that is why in the present case also there is more carpogenic germination in those 

soil samples which exhibit less cation exchange capacity. Maximum positive correlation was found 

in Ca 2+ , HCO 3 - , Cl - and SO 4 2- with other characters. 

Table 3. Suppressive and conducive soils influenced by soil Physical and Chemical 

properties 

Disease(s) 

Soil properties 

A. Where the pathogen does not establish 

Fusarium wilt of Banana 

Sandy soil (C), Clay soil (S) 

Fusarium wilt of cotton 

Fusarium root rot of wheat 

Fusarium wilt of peas 

Fusarium root rot of bean 

Aphanomyces root rot of peas 

Phymatotrichum root rot of cotton 

Pine root rot 

Verticillium wilt of sunflower 

Acidic soil (C) 

Sandy soil, low organic matter and low rainfall (C) 

Fine textured, high organic matter and high rainfall (S) 

Heavy clay soil (S) 

Loessial (C) Lacustrine (S) 

Aluminum ions (S) 

Alkaline soils (C) 

Light soil (C) Heavy soil (S) 

Aluminum ions (S) 

B. Pathogen establishes but fails to cause disease 

Aphanomyces root rot of peas 

Fusarium root rot of beans 

Phytophthora root rot of avocado 

Phytophthora root rot of avocado 

Verticillium wilt of cotton 

Compact soil (C) 

Compact soil (C) 

Abiotic fungistatic factors (S) 

High organic matter (S), 

High exchangeable calcium (S) 

Copper induced fungistasis (S) 

C. Pathogen establishes, produces disease for a while but then declines 

Fusarium root rot of bean 

Phymatotrichum root rot of cotton 

Scab of potato 

Rhizoctonia damping off of radish 

Take-all of wheat 

Continuous crop (S) 

High exchangeable sodium (S) 

Continuous potatoes (S) 

In rotation with sugar beet, oats and maize (C) 



Mechanisms of biocontrol: 

A. Single organism: The following are examples of each of the documented mechanisms of 

- 162 -


biocontrol with a single organism. 

1. Antibiosis: Antibiosis refers to the production of antibiotics. Pythium zoospores attack 

plant roots. However, when roots are treated with a biocontrol bacterium, Bacillus cereus, 

disease is prevented. The bacteria produce an antibiotic zwittermicin A that prevents the 

germination of zoospore cysts which contributes to the protection from disease. 

2. Competition for nutrients: Some biocontrol agents consume chemicals that the pathogen 

needs as a cue to germinate or a vital nutrient for growth. Sporangia of Pythium ultimum lie 

dormant in the soil until they are exposed to linoleic acid, a fatty acid released by 

germinating seeds. Linoleic acid acts as a germination cue which initiates infection. The 

bacterium Enterobacter cloacae metabolizes linoleic acid thus removing the cue to 

germinate. Although the Pythium sporangium is still viable, it does not germinate and no 

infection occurs. 

3. Parasitism: Some biocontrol agents carry out direct parasitism of the pathogen. For 

example, fungi of the genus Trichoderma encircle Pythium hyphae, puncture the cell wall 

and drain cellular contents. Several commercially available biocontrol formulations include 

Trichoderma species. 

4. Induced systemic resistance: Plants have a system of protection against pathogens that 

is somewhat analogous to mammalian immune systems. One component of this is Induced 

Systemic Resistance or ISR. In split pot experiments with cucumber plants, one part of the 

root system was exposed to the bacterium Pseudomonas corrugata. A separate part of the 

root system was exposed to Pythium aphanidermatum zoospores, but in plants treated with 

the bacteria no disease occurred. In this case the biocontrol bacterium had no direct 

contact with the plant pathogen. Instead, the bacterium initiated the plant’s defense 

response and a phloem mobile signal carried this information to the other parts of the plant. 

With the arrival of this chemical signal, the plant starts to make protective compounds like 

antioxidants, nitrous oxide, and hydrogen peroxide that can lessen the tissue damage 

caused by pathogens. 

B. Multiple organism biocontrol: While scientists have learned a substantial amount about how 

individual species of microbes can prevent plant disease, understanding how the complex 

communities of microorganisms present in soil, compost and decomposing cover crops suppress 

disease has proven much more difficult. Although some commercial compost testing facilities 

claim to be able to predict which compost will be suppressive with certain biological 

measurements, there is no scientific basis for this claim. The reality of the situation is much more 

complicated. 

Conclusion 

Because of the high variability in compost‐ mediated suppression of different pathogens, 

finding measurements that can predict overall suppressiveness may be unrealistic. In the future, 

- 163 -


predictive factors may be pathosystem specific. Opportunities for collaboration exist among 

growers, compost producers and researchers to continue to improve the efficacy of compost use 

for plant disease suppression. 

REFERENCES 

• Bonanomi, G., Antignani, V., Capodilupo, M., and Scala, F. 2010. Identifying the characteristics of 

organic soil amendments that suppress soilborne plant diseases. Soil Biology and 

Biochemistry 42: 136‐ 144. 

• Burke, D.W. 1965. Fusarium root rot of beans and behavior of the pathogen in different soils. 

Phytopathology 55: 1122 

• Chaube, H.S. 1989. Pathogen suppressive soil, In: Perspectives of Phytopathology, V.P. Agnitre, 

et al. (Eds), Today and Tomorrow Printer, New Delhi 

• Singh, U.P., Singh, K.P., and Shahi, D.K. 1991. Carpogenic germination of sclerotia of Sclerotinia 

sclerotiorum in some soil samples differing in H, organic carbon, silt, clay, sand 

and ion exchange capability. Phytophylloctica 23: 241 - 243. 

• Singh, K.P., Shahi, D.K., and Singh, U.P. 1995. Carpogenic germination of sclerotia of 

Sclerotinia sclerotiorum in some soil samples differing in ion exchange and soil 

nutrients properties. Tropical Science 35: 354 - 358. 

• Sullivan, P. 2004. Sustainable management of soil-borne plant diseases. Soil System Guide, 

National Sustainable Agriculture Information Service, ATTRA. 

- 164 -

Introduction 


Pesticides: Past, Present and Future 

R.P. Srivastava 

Department of Entomology, G.B.P.U.A.&T., Pantnagar- 263 145 (Uttarakhand) 

Agriculture is an important sector of the Indian economy and vital for the food and 

nutritional security of the nation. Ensuring food security for more than 1 billion Indians with 

diminishing cultivable land resources is a herculean task. This necessitates use of high yielding 

variety of seeds, balanced use of fertilizers, judicious use of quality pesticides along with education 

of farmers and use of modern farming techniques. In order to meet the needs of a growing 

population, agricultural production and protection technology have to play a crucial role. 

Substantial food production is lost due to insect pests, plant pathogens, weeds, rodents, birds, 

nematodes and during storage. 

Pesticides industry has developed substantially and has contributed significantly towards 

India’s agriculture and public health. In value terms the size of the Indian pesticide industry was 

$3.8 billion in the year 2011. India is a predominant exporter of pesticides to USA, Europe and 

African countries. Recently, the domestic industry is characterized by over-capacity, low capacity 

utilization and unsustainable levels of production from many units and low investments in R&D. 

Besides, the formulation market is highly fragmented with large number of small formulators. 

Globally, there is a growing trend towards low dosage, high potency molecules and as such, 

market for usage of high volume pesticides is declining. With the advent of the integrated pest 

management (IPM) technique, the use of bio pesticides and genetically modified (GM) seeds has 

increased globally. 

Pest Species, Crop Loss and Benefits of Pesticides Application 

Worldwide, approximately 10,000 species of insects and mites, 50,000 species of plant 

pathogens, and 8,000 species of weeds damage crops.The losses caused by insect pests 

estimated at 14%, plant pathogens 13%,and weeds 13% .Pesticides are therefore indispensable in 

agricultural production. About one-third of the agricultural products are produced by using 

pesticides. Without pesticide application the loss of fruits, vegetables and cereals from pest injury 

would reach 78%, 54% and 32% respectively. Crop loss from pests declines to 35- 42% when 

pesticides are used. 

Worldwide Pesticides Use and Reach to Non-Target 

Globally 4.6 million tons of chemical pesticides are annually sprayed into the environment. 

There are currently about 500 pesticides with mass applications, of which organochlorine 

pesticides, some herbicides and the pesticides containing Hg, As, and Pb are highly poisonous to 

the environment. Only 1% of the sprayed pesticides are effective (reach to the target), 99% of 

pesticides applied are released to non-target soils, water bodies and atmosphere, and finally 

absorbed by almost every organism. 

- 165 -


Pesticides, Non-target Organisms and our environment 

Regarding effect on non target organisms, the most important publication was Rachel 

Carson’s best-selling book “Silent Spring,” published in 1962. She (a scientist) issued grave 

warnings about pesticides, and predicted massive destruction of the planet’s fragile ecosystems 

unless more was done to halt what she called the “rain of chemicals.” In retrospect, this book really 

launched the environmental movement. 

She was focusing on the chlorinated hydrocarbons, such as DDT, and pointed to evidence 

linking them to death of non target creatures (organisms other than those that the pesticide is 

intended to kill), such as birds. She argued that the death of non targets occurred via two basic 

ways: 

1) Direct toxicity - It was discovered that DDT was toxic to fish (especially juveniles) and crabs, 

not only to insects. 

2) Indirect toxicity - related to its persistence. (Its persistence came in part from its insolubility; 

from the fact that it was a synthetic, recently introduced compound that micro-consumers, such as 

bacteria, lacked enzymes capable of degrading - basically they hadn’t evolved to use it as an 

energy source, as well as from other features of its chemistry.) 

The indirect toxicity related to two principles: 

i. Bioconcentration - the tendency for a compound to accumulate in an organism’s tissues 

(especially in fatty tissues for fat soluble organochlorines such as DDT) 

ii. Biomagnification - an increase in concentration up the food chain (These terms are 

sloppily used; sometimes “bioaccumulation” is also used to mean for both the terms) 

(Source: http://oregonstate.edu/~muirp/ pesthist.htm) 

Pesticide: Global Scenario 

Global generic market of pesticides was $45 billion. Export opportunities for Indian 

companies are immense with key markets being USA, France, Netherlands, South Africa, and 

Bangladesh. 

Indian Scenario: Production Trends 

India is the 4th largest producer of pesticides after USA, Japan and China. India is the 

second largest producer of pesticides in Asia. According to the Centre for Monitoring Indian 

Economy (CMIE), pesticide production in India for FY10 stood at 6.2 lakh tonnes. CMIE has taken 

production details from the annual reports of the pesticide companies. It could be much higher as 

there are lot of small unauthorised individuals and companies manufacturing pesticides without 

product registration. There is no data available on that. The presence of these small players has 

resulted in driving down the prices due to fierce competition. 

The total market size in India, including exports, for 2009 was approximately Rs.70 bn. 

According to a latest report released by Research on India, a leading provider of market 

intelligence reports on leading industries, the market is expected to grow at CAGR of 2.38% for 

- 166 -


next 3 years. The Indian pesticides industry has been growing at 8-9% p.a. over the past five 

years (FY07-FY11). Industry size is estimated to be $3.8 billion in FY11 with exports accounting 

for 50% of the market. Over the XIIth plan period, the segment is expected to grow at 12-13% 

p.a. with domestic demand growing at 8-9% p.a. and export demand at 15-16% p.a. Three broad 

categories of companies are present in the industry - Multi-National, Indian including the public 

sector companies and small sector units. There are about 125 technical grade pesticides 

manufacturers in the country of which about 60 are in the organized sector, and 10 are, 

multinationals. There are about 800 pesticides formulators in the country. Most Indian technical 

manufacturers are focused on off-patent pesticides. 

Pesticide Consumption 

Pesticides are among the crucial inputs required to sustain and improve the agricultural 

production in country. Substantial amount of crop is lost due to attack from pests. What is 

surprising is that, despite the country’s huge agricultural base, pesticide consumption in India is 

one of the lowest in the world with per hectare consumption of less than one kg compared to US 

(4.5 kg/ha) and Japan (11 kg/ha). Consumption could be low for the following reasons: 

‣ Lack of awareness among the farmers about different types of pesticides available and their 

impact on environment. 

‣ Pesticide is the last input in agricultural cropping operation; hence, farmers generally have no 

surplus money left and start using them only after the pest attack. 

Consumption is mainly driven by cotton and paddy crops. 

In India pesticide use is 

extended to approximately 16.7 mn hectares, which is just 9% of the total cultivable land. 

Insecticide accounts for largest share in consumption in India followed by herbicide and fungicide, 

unlike high herbicide and fungicide usage globally. This is probably because India‘s tropical 

climate is conducive for the multiplication of insects. 

List of pesticides which are banned, refused registration and restricted in use (As on 31 th 

Dec, 2012) 

I. PESTICIDES / FORMULATIONS BANNED IN INDIA 

A. Pesticides Banned for manufacture, import and use 

1. Aldicarb 15. Heptachlor 

2. Aldrin 16. Lindane (Gamma-HCH)* 

3. Benzene Hexachloride 17. Maleic Hydrazide 

4. Calcium Cyanide 18. Menazon 

5. Chlorbenzilate 19. Metoxuron 

6. Chlordane 20. Nitrofen 

7. Chlorofenvinphos 21. Paraquat Dimethyl Sulphate 

8. Copper Acetoarsenite 22. Pentachloro Nitrobenzene 

9. Dibromochloropropane 23. Pentachlorophenol 

10. Dieldrin 24. Phenyl Mercury Acetate 

- 167 -


11. Endrin 25. Sodium Methane Arsonate 

12. Ethyl Mercury Chloride 26. TCA (Trichloro acetic acid) 

13. Ethyl Parathion 27. Tetradifon 

14. Ethylene Dibromide 28. Toxaphene(Camphechlor) 

*(Banned vide Gazette Notification No S.O. 637(E) Dated 25/03/2011)-Banned for 

Manufacture,Import or Formulate w.e.f. 25th March,2011 and banned for use w.e.f. 25th 

March,2013. 

B. Pesticide formulations banned for import, manufacture and use 

1. Carbofuron 50% SP 3. Methomyl 24% formulation 

2. Methomyl 12.5% L 4. Phosphamidon 85% SL 

C. Pesticide / Pesticide formulations banned for use but continued to 

manufacture for export 

1. Captafol 80% Powder 2. Nicotin Sulfate 

D. Pesticides Withdrawn 

1. Dalapon 5. Paradichlorobenzene (PDCB) 

2. Ferbam 6. Simazine 

3. Formothion 7. Warfarin 

4. Nickel Chloride 

II. 

PESTICIDES REFUSED REGISTRATION 

S.No. Name of Pesticides 

S.No. Name of Pesticides 

1. Ammonium Sulphamate 10. Fentin Acetate 

2. Azinphos Ethyl 11. Fentin Hydroxide 

3. Azinphos Methyl 12. Lead Arsenate 

4. Binapacryl 13. Leptophos (Phosvel) 

5. Calcium Arsenate 14. Mephosfolan 

6. Carbophenothion 15. Mevinphos (Phosdrin) 

7. Chinomethionate (Morestan) 16. 2,4, 5-T 

8. Dicrotophos 17. Thiodemeton / Disulfoton 

9. EPN 18. Vamidothion 

- 168 -


III. PESTICIDES RESTRICTED FOR USE IN THE COUNTRY 

S.N 

o 

Name 

Pesticides 

1. Aluminium 

Phosphide 

of 

Details of Restrictions 

The Pest Control Operations with Aluminium Phosphide may be 

undertaken only by Govt./Govt. undertakings / Govt. Organizations / 

pest control operators under the strict supervision of Govt. Experts or 

experts whose expertise is approved by the Plant Protection Advisor to 

Govt. of India except 1 Aluminium Phosphide 15 % 12 g tablet and 

2 Aluminum Phosphide 6 % tablet. 

[RC decision circular F No. 14-11(2)-CIR-II (Vol. II) dated 21-09-1984 

and G.S.R. 371(E) dated 20 th may 1999]. 1 Decision of 282 nd RC held on 

02-11-2007 and, 2 Decision of 326 th RC held on 15-02-2012. 

The production, marketing and use of Aluminium Phosphide tube packs 

with a capacity of 10 and 20 tablets of 3 g each of Aluminium 

Phosphide are banned completely. (S.O.677 (E) dated 17 th July, 2001) 

2. Captafol 

3. Cypermethrin 

4. Dazomet 

5. Diazinon 

6. 

Dichloro 

Diphenyl 

Trichloroethane 

(DDT) 

7. Fenitrothion 

8. Fenthion 

The use of Captafol as foliar spray is banned. Captafol shall be used 

only as seed dresser. (S.O.569 (E) dated 25 th July, 1989) 

The manufacture of Captafol 80 % powder for dry seed treatment (DS) 

is banned for use in the country except manufacture for export. 

(S.O.679 (E) dated 17 th July, 2001) 

Cypermethrin 3 % Smoke Generator, is to be used only through Pest 

Control Operators and not allowed to be used by the General Public. 

[Order of Hon,ble High Court of Delhi in WP(C) 10052 of 2009 dated 

14-07-2009 and LPA-429/2009 dated 08-09-2009] 

The use of Dazomet is not permitted on Tea. 

(S.O.3006 (E) dated 31 st Dec, 2008) 

Diazinon is banned for use in agriculture except for household use. 

(S.O.45 (E) dated 08 th Jan, 2008) 

The use of DDT for the domestic Public Health Programme is restricted 

up to 10,000 Metric Tonnes per annum, except in case of any major 

outbreak of epidemic. M/s Hindustan Insecticides Ltd., the sole 

manufacturer of DDT in the country may manufacture DDT for export to 

other countries for use in vector control for public health purpose. The 

export of DDT to Parties and State non-Parties shall be strictly in 

accordance with the paragraph 2(b) article 3 of the Stockholm 

Convention on Persistent Organic Pollutants (POPs). 

(S.O.295 (E) dated 8 th March, 2006) 

Use of DDT in Agriculture is withdrawn. In very special circumstances 

warranting the use of DDT for plant protection work, the state or central 

Govt. may purchase it directly from M/s Hindustan Insecticides Ltd. to 

be used under expert Governmental supervision. 

(S.O.378 (E) dated 26 th May, 1989) 

The use of Fenitrothion is banned in Agriculture except for locust control 

in scheduled desert area and public health. 

(S.O.706 (E) dated 03 rd May, 2007) 

The use of Fenthion is banned in Agriculture except for locust control, 

household and public health. (S.O.46 (E) dated 08 th Jan, 2008) 

- 169 -


9. Lindane 

(Gamma-HCH) 

10. 

Methoxy 

Mercuric 

Chloride 

(MEMC) 

Ethyl 

11. Methyl Bromide 

12. Methyl 

Parathion 

13. Monocrotophos 

14. Sodium Cyanide 

Lindane is banned for manufacture, import or formulate. However it is 

allowed for use up to 24 th march, 2013 for termite control in Building 

including wood, and termite control in Agriculture as per approved label 

claims by the Registration Committee and for exports. 

[S.O.637 (E) dated 25 th March, 2011 AND S.O.1472 (E) dated 29 th Aug., 

2007] 

The use of MEMC is banned completely except for seed treatment of 

potato and sugarcane. (S.O.681 (E) dated 17 th July, 2001) 

Methyl Bromide may be used only by Govt./Govt. undertakings/Govt. 

Organizations / Pest control operators under the strict supervision of 

Govt. Experts or Experts whose expertise is approved by the Plant 

Protection Advisor to Govt. of India. 

[G.S.R.371 (E) dated 20 th May, 1999 and earlier RC decision] 

Methyl Parathion 50 % EC and 2% DP formulations are banned for use 

on fruits and vegetables. 

(S.O.680 (E) dated 17 th July, 2001) 

The use of Methyl Parathion is permitted only on those crops approved 

by the Registration Committee where honeybees are not acting as a 

pollinators. (S.O.658 (E) dated 04 th Sep., 1992.) 

Monocrotophos is banned for use on vegetables. 

(S.O.1482 (E) dated 10 th Oct, 2005) 

The use of Sodium Cyanide shall be restricted for Fumigation of Cotton 

bales under expert supervision approved by the Plant Protection 

Advisor to Govt. of India. (S.O.569(E) dated 25 th July, 1989) 

Employment 

Pesticides manufacturing sector provides direct and indirect employment to approximately 

60,000 people, nearly 10,000 of these working in pesticides manufacturing units. In the XIIth five 

year plan, the industry envisages employment increase to the extent of 7%. 

Pesticide: Export 

India is a net exporter of pesticides. Exports account for ~50% of the pesticides market. 

Indian exports of pesticides grew at ~ 15% p.a. during the XIth plan period and will continue to 

grow at the same rate during the XIIth 5 year plan period. The key export destination markets are 

USA, France, Netherlands, Belgium, Spain, South Africa, Bangladesh, Malaysia and Singapore. 

Some of the agro-chemicals exported over the years include Isoproturon, Endosulphan, Aluminium 

Phosphide, Mancozeb, Cypermethrin, Thiamethoxam, Imidacloprid etc. 

Exports in value terms have almost doubled from Rs.27.9 bn in 2006 to Rs.52.2 bn in 

2010. Exports have grown at CAGR of 13.48% over the past five years. Manufacturers have 

shifted their focus more towards exports due to domestic seasonal demand, better price realisation 

in the global market, domestic overcapacity and low credit periods. India also has an advantage of 

low manufacturing cost due to availability of cheap and high quality scientific pool. 

Strengths & opportunities 

1) Cost competitiveness: But for taxes and levies, Indian producers can make available the 

product at the cheapest price available in the world. Low cost manufacturing base leads to 

- 170 -


competitive cost of production of pesticides especially Pyrethroids, Organo Phosphorous 

(OP) Ester etc. 

2) Huge export potential: The excess production capacity is a perfect opportunity to 

increase exports by utilizing India’s low cost producer status. 

3) Growth in demand for food grains: India has 16% of the world’s population and less than 

2% of the total landmass. Increasing population and high emphasis on achieving food grain 

self sufficiency is expected to increase growth of pesticides industry. 

4) Limited farmland availability: India has more than 190 million hectares of gross 

cultivated area and scope of bringing new areas under cultivation is severely limited. 

Available agriculture land per capita has been reducing globally and is expected to reduce 

further. The pressure is therefore to increase yield per hectare which can be achieved 

through increased usage of pesticides. 

5) Growth of horticulture & floriculture: Growing horticulture and floriculture industries will 

result in increasing demand for pesticides especially fungicides. 

6) Increasing awareness: There is loss of crops due to non-use of pesticides. Companies 

are increasingly training farmers regarding right use of pesticides in terms of quantity to be 

used, the right application methodology and appropriate chemicals to be used for identified 

pest problems. With increasing awareness, the use of pesticides is expected to increase. 

7) Patent expiry: In the year 2014, many molecules are likely to go off patent throwing the 

market open for generic players. Pesticides industry in India can exploit this opportunity. 

8) Product portfolio expansion: Threats like genetically modified seeds, integrated pest 

management (IPM), organic farming etc can be turned into opportunities if the industry reorients 

itself to better address the needs of its consumers and broadens its product offering 

to include a range of agri-inputs instead of only pesticides. 

9) Environment friendly pesticides: The issue of monitoring of pesticide residues in food 

and agricultural commodities will occupy an important position both in domestic sale and 

export of agrobased products. There will be a gradual shift towards pesticides that are user 

and environmental friendly. 

10) R&D in pesticides: Prior to 2005, i.e. in the process patent regime, Indian companies 

concentrated on marketing generic and off patent products. Due to this, the R&D 

expenditure by Indian companies was lower at approximately 1% of turnover. Global 

companies focused on high end specialty products and dominated the market for patent 

new molecules and globally, pesticides companies spend 8-10% of their turn over on R&D. 

However, with the onset of the product patent regime in India, the Indian companies will 

need to increase R&D expenditure to meet competition from global market. Alternatively 

Indian companies can also be competitive in the area of Contract Research and 

Manufacturing Services (CRAMS). 

- 171 -


Challenges & weaknesses 

1) High cost of power & finance: Very high cost of power, unreliability of supply and 

frequent interruption with high transmission and distribution losses. Chemical industry is 

highly capital-intensive and high cost of finance in India is a challenge (interest rate 14%- 

15% p.a. as compared to 2% to 6% prevailing in developed countries). 

2) Infrastructure: Poor transport and communication infrastructure, resulting in delays and 

slow movement of goods. 

3) Scale of production: The plant sizes are not comparable to world-scale operations 

effecting to cost of production. 

4) Labour laws: Labour laws at present do not allow flexibility in deployment of labour. This 

discourages modernization and investment in technological changes and eventually leads 

to industrial sickness, thus adversely affecting workers as well. Cumbersome and 

complicated product development process from inception to registration to manufacture, 

formulation and sale.Luke warm response of Centre and State Governments in 

strengthening quality control enforcement, in comparison to other agriculture inputs like 

fertilizers (50% subsidy) and seeds (no excise duty and taxes), pesticides are excisable 

and multipoint taxable. 

5) R&D costs: R&D to develop a new agrochemical molecule takes an average of 9 years 

and high cost on research. Indian companies have to focus on developing newer 

molecules and will face challenges in building these capabilities. 

6) Threat from Genetically Modified (GM) seeds: Genetically modified seeds possess self 

immunity towards natural adversaries which have the impact on the business of pesticides 

7) Need for efficient distribution systems: Since the number of end users is large and 

widespread, effective distribution via retailers is essential to ensure product availability. 

Lately companies have been directly dealing with retailers by cutting the distributor from 

the value chain thereby reducing distribution costs, educating retailers on product usage 

and offering competitive price to farmers 

8) Support for Integrated Pest Management (IPM) & rising demand for Organic farming: 

Promotion of IPM and usage of bio-pesticides is gaining momentum. With increasing 

demand for organic food, farmers have reduced chemical usage and have adopted organic 

farming. Agrochemical companies will have to tackle the rising environment awareness and 

address concerns on negative impact of pesticide usage. 

9) Counterfeit products: The spurious pesticides market has a negative impact on the 

organized sector revenues and farmers. 

Action plan 2012-2017 

Based on the export potential and potential for increased penetration in the domestic 

market, the Indian agrochemical industry can target a size of $7.7 billion by FY17 (up from existing 

- 172 -


$3.8 billion). However, achieving this target will require governmental support and the industry 

initiative with regard to the following aspects: 

1) Registration of pesticides: Delay in getting product registrations leads to delay in exports, 

hampering India’s exports. The procedure should be simplified and time bound registration and 

issue of registration certificate for export within 30 days from receipt of request from exporter/ 

manufacturer should be ensured. Efficiency of Central Insecticides Board & Registration 

Committee (CIB & RC) should be increased by bringing more transparency, implementing robust 

and secured online data submission 

2) Multiple governing authorities for crop protection: Pesticides come under Dept. of 

Chemicals and Petrochemicals, Ministry of Agriculture and Ministry of Health & Family Welfare. 

These activities falling under different ministries should be merged. Government could explore 

setting up a separate division under Dept. of Chemicals & Petrochemicals which could deal with all 

the issues such as pesticide registration, its use, fixation of standards for residue in food chain etc. 

3) Environmental clearance should be speed up through single window clearance for setting up 

pesticides manufacturing plants. Once a factory is cleared from the environment point of view, any 

product changes (within selected parameters) could be allowed without seeking additional 

clearances. 

4) Ambivalence prevails about the use of pesticides: There is need to pro-actively educate 

farmers for the safe, appropriate and judicious use of pesticides. A clear national policy directive is 

needed to increase pesticide usage, as at present the coverage is only about 20% of cultivated 

areas resulting 10 to 30% crop loss due to pests and weeds 

5) Spurious pesticides: The presence of spurious pesticides in the market is a major problem. 

The problem can be tackled by adopting the following approach: 

i) Improve the method of sampling, and make the inspectors accountable 

ii) Pesticide testing labs need to be upgraded and should be mandated to seek accreditation from 

NABL (National Accreditation Board for Laboratories) i.e. ISO 17025 certification 

iii) Industry members or independent quasi-government agencies should be allowed to undertake 

surprise visits to these labs 

iv)A joint analysis of samples through an independent laboratory which is accredited by NABL 

should be considered 

V) Insecticides Act, 1968 should be reviewed and amended for any loopholes that can be 

exploited to support spurious pesticide manufacturers 

6) Recognize pesticides as a knowledge based industry: The pesticides industry is to be 

provided the same support as pharmaceuticals. This would support investment in R&D 

7) Budgetary support to pesticides industry: Considering crop losses due to pests, weeds and 

diseases, there is urgent need for the following budgetary support: 

i) The pesticide industry is to be treated equal to fertilizer industry and the government to reduce 

- 173 -


central excise duty from the present 10% to 4%. This will reduce costs, resulting in increased 

usage of plant protection chemicals to reduce crop losses 

ii) Section 35(2AB) of the Income Tax Act should be amended to provide weighted deduction of 

expenses for the following: 

a) Agriculture extension work such as undertaking demonstration and training to farmer and all 

expenses connected thereto 

b) Development, upkeep and use of agricultural web sites 

c) Undertaking of R&D work in-house or through agricultural universities or reputed research 

organizations 

d) Farmer meetings for sharing best practices and their familiarization tours for education and 

training 

e) Fees & expenses paid to experts for dissemination of information and best practices to farmers/ 

users 

f) Knowledge dissemination through media or otherwise. 

iii) All agricultural inputs should be treated as far as taxes, levies and subsidies are concerned, at 

par. 

iv)Government should consider and allocate funds for educating end users/ farmers for the benefit 

of pest control and also safe and judicious use of pesticides 

v) Government should encourage latest technology adoption measures among farmers and create 

farmer panels for key crops across India 

8) To ensure better adherence to Safety, Health & Environment (SHE) and Good Manufacturing 

Practices (GMP) norms for crop protection, Government should make efforts to guide SMEs 

Target for XII TH five year plan 

The Indian pesticides industry grew at a rate of 8-9% over the past five years (FY07-FY11). 

Industry size is estimated to be $3.8 billion in FY11 with exports accounting for ~50% of the 

market. Over the XII th plan period, the segment is expected to grow at 12-13% p.a. with domestic 

demand growing at 8-9% p.a. and export demand growing at 15-16% p.a. Based on the export 

potential and potential for increased penetration in the domestic market, the Indian agrochemical 

industry target a size of US $7.7 billion by FY17. 

Chemical management in india: policy and legislative framework 

Development of Chemical Management Regime: 

India’s environment management efforts started quite early, after independence in 

1947.The Insecticides Act to regulate the harmful impacts of pesticides was passed in 1968.After 

the Stockholm Conference in 1972, India enacted two major environmental laws- The Water 

(Prevention and Control of Pollution) Act in 1974, passed for the purpose of prevention and control 

of water pollution, followed by the Air (Prevention and Control of Pollution) Act in 1981.It also led to 

the institutionalization of the regulatory infrastructure through the establishment of the Central and 

- 174 -


State Pollution Control Boards (SPCB). 

However, it was after the Bhopal disaster in 1984 that chemical safety issues became 

specifically recognised through the passing to umbrella legislation, the Environmental Protection 

Act (EPA) 1986, under which specific rules on chemical safety have been framed from time to 

time. Subsequently, after the Rio Summit in 1992, the World Summit on Sustainable Development 

(WSSD) held in Johannesburg in 2002, which adopted the 2020 goal, as well as the Strategic 

Approach to International Chemical Management (SAICM) process, chemicals safety –has slowly 

become part of an overall development policy agenda.Even the Indian Planning Commission, the 

highest national planning body has recognised this in its ongoing Eleventh 5-Year plan. Serious 

environmental health problems affect millions of people who suffer from respiratory and other 

diseases caused or exacerbated by biological and chemical agents, both indoors and outdoors. 

Millions are exposed to unnecessary chemical and physical hazards in their home, workplace or 

wider environment (Plannning Commission, 2007). 

In terms of legislation, India is well placed , even there are gaps. Almost in all steps of 

chemical management from cradle to grave, some legislation has been laid down and consists of 

more than 15 Acts and 19 Rules (National Chemical Management Profile, 2006). Yet areas such 

as substitution of hazards in products and processes or the remediation of contaminated sites 

need attention. 

Constitutional provisions 

The Indian Constitution, through its 42 nd amendment, under Article 48 states,”The state 

shall endeavour to protect and improve the environment and to safeguard the forests and wildlife 

of the country”. Through various judgements , the Indian Supreme Court has also interpreted the 

provisions of Article 21, which enshrines a Right to Life to hold that environmental degradation 

violates the fundamental right to life. 

The Environment (Protection) Act 1986, amended 1991 

The EPA is a fundamental act enabling umbrella legislation, under which the designated 

ministry in the Central Government (Ministry of Environment and Forests, MOEF) can frame rules 

and procedures to deal with chemical safety issues. It provides for both criminal as well as civil 

penalties and severe fines for violations as well as imparts wide ranging powers for regulators to 

take action in the event of non-compliance to the Act, including ordering the closure of units. 

However, since these penaltiess have been ineffectual, this is now being re-examined to make this 

a real deterrent. 

Future Challenges 

To develop more and more new molecules having 

1) Low mammalian toxicity 

2) Less soluble in water 

3) Leaching potential shall be less or absent 

- 175 -


4) New new chemistry 

5) Molecular weight of new molecules shall be ranged from 200-450 

6) More discoveries in macromolecular pesticides 

7) More innovations required for new neo-nicotinoids 

8) More biotechnological innovations to be directed in 

9) Transgenic plants etc. 

10) More innovative technology to be developed in application of pesticides, a special care 

shall be given on the nozzles, sprayer or applicator with an intention to minimize the loss of 

applied pesticide or target organisms 

11) Minimization of residue load in ecosystem 

12) More emphasis shall be given in bio-control agents. 

13) Research emphasis shall be given in innovations of more plant derived bio-pesticides 

REFERENCE 

• Bhattacharyya A., Suhrid R B and Ganguly P. 2009. New pesticide molecules, formulation 

technology and uses: Present status and future challenges. The Journal of Plant 

Protection Sciences, 1(1): 9-15. 

• http://www.cibrc.nic.in/reg_products.htm(2007) 

• http://www.epa.gov/opp00001/biopesticides/ Environmental Protection Agency of the USA 2012. 

Regulating Biopesticides. ( Accessed April 2012) 

• http://www.epa.gov/pesticides/factsheets/chemical_fs.htm 

• http://www.ncipm.org.in/asps/pesticides 

• http://oregonstate.edu/~muirp/ pesthist.htm 

• Huang K., Xia L., Zhang Y., Ding X, Zahn A.J.(2009).Recent advances in the biochemistry of 

spinosyns.Appl Microbiol Biotechnol 82:13–23. 

• IRAC 2012. IRAC MoA Classification Scheme. www.irac-online.org or enquiries@irac-online.org 

(accessed April 2012) 

• Nollet L.M.L and Rathore H.S.2010.Handbook of Pesticides Methods of Pesticide Residues 

Analysis. CRC Press, Taylor and Francis group, Boca Raton. 

http://www.tylorandfrancis.com, http://www.crcpress.com. 

• Waxler P., Kolk J. V. D., Mohapatra A and Agarwal R. 2012. Chemicals, Environment, Health A 

global Management Perspective. CRC Press, Taylor and Francis group New York. 

• WenJun Zhang., FuBin Jiang and Jian Feng Ou. 2011. Global pesticide consumption and pollution: 

with China as a focus. Proceedings of the International Academy of Ecology and 

Environmental Sciences, 1(2):125-144 

- 176 -


Isolation, Identification and Quantification of Trichoderma 

Roopali Sharma, Smita Puri and Erraya 


Isolation of Trichoderma species- Select healthy plants from standing crop of desired location 

and collect the rhizospheric soil (soil tightly adhering the root) by gently and carefully uprooting the 

plant. 

Materials required- Trichoderma selective medium (TSM)- MgSO 4 .7H 2 O (0.2 g), K 2 HPO 4 (0.9 g), 

KCl (0.15 g), NH 4 NO 3 (1.0 g), Glucose (3.0 g), Chloramphenicol (0.20 g), Apron 35SD (0.015 g), 

Captan (0.2 g), Rose Bengal (0.15 g), Agar-agar (20 g) and 1 L distilled water (Elad et al., 1981), 

Potato Dextrose Agar (potato- 200g, dextrose-20g and agar -20g), 4% water agar (40 g agar in 1l 

water) Petri plates, sterile water, measuring cylinder, pipette, tips, rose bengal, antibiotics. 

Isolation from rhizosphere 

Serial dilution technique (Krassilnikov, 1950) is used for isolation of Trichoderma from 

rhizospheric soil. 

1. Air dry soil samples for 4 h. 

2. Suspend 10 g soil in 100 ml of sterile distilled water (1:10) and stirred well. 

3. Allow the soil particles to settle down, transfer 10 ml of clear supernatant to another flask 

containing 90 ml sterile distilled water (1:100). 

4. Prepare serial dilutions 10 -2 to 10 -6 by following same procedure. 

5. Prepare Trichoderma selective medium (TSM) for isolation of Trichoderma. 

6. Dissolve antibiotics and fungicides in 50 ml of 30 per cent ethyl alcohol and add in to the 

medium prior to pouring into Petri plates. 

7. Take 1 ml of each dilution 10 -4 to 10 -6 with help of 5 ml pipette and pour it on the Petri plate 

seeded with TSM in an inoculation chamber under aseptic conditions. 

8. Incubate the plates at 28±1 ° C for 5 days. 

9. Record observations on the appearance of the colonies from 3 rd to 5 th day. 

10. Pick individual colony and maintain the pure culture. 

Isolation from rhizoplane 

Take root pieces of a plant in 100ml sterile water and shake it well. 

1. Give 10-20 Serial washings to the above roots with sterilized water until clear root surface 

is exposed. 

2. Place the washed roots on Petri plates having TSM. 

3. Incubate the plates for 5-7 days at 25°C. 

Isolation from phylloplane 

1. Collect fresh healthy leaves in sterile polythene bags. 

2. Transfer 10g of these leaves to 100 ml sterile water and stir for 20 min using magnetic 

stirrer. 

3. Prepare serial dilutions up to 10 -3 . 

4. Transfer 1 ml aliquot from all the dilutions to sterile Petri plates and pour TSM. 

- 177 -


5. To get the colonies of antagonistic fungi, incubate the plates for 5-7 days at 25°C. 

Purification of Trichoderma culture 

1. Purify Trichoderma isolates single spore culture. 

2. Inoculate spores of isolates onto a Petri dish seeded with 4% Water agar. 

3. With the help of binocular, select and transfer single germinating spore in slants having 

PDA with the help of inoculation needle. 

4. Incubate the cultures at 25±1 ° C for 5 days and store at 4 ° C. 

Quantification of spores through haemocytometer 

In Plant pathology, microbiology and cell culture there are many applications that require 

use of suspensions of cells, for this purpose it is necessary to determine cell concentration. One 

can often determine cell density of a suspension spectrophotometrically, however that form of 

determination does not allow an assessment of cell viability, nor can one distinguish cell types. 

A device used for determining the number of cells per unit volume of a suspension is called 

a counting chamber. The most widely used type of chamber is called a hemocytometer, since it 

was originally designed for performing blood cell counts. 

Preparation of counting chamber- To prepare the counting chamber the mirror-like polished 

surface is carefully cleaned with lens paper. The coverslip is also cleaned. Coverslips for counting 

chambers are specially made and are thicker than those for conventional microscopy, since they 

must be heavy enough to overcome the surface tension of a drop of liquid. The coverslip is placed 

over the counting surface prior to putting on the cell suspension. The suspension is introduced into 

one of the V-shaped wells with a pasteur or other type of pipet. The area under the coverslip fills 

by capillary action. Enough liquid should be introduced so that the mirrored surface is just covered. 

The charged counting chamber is then placed on the microscope stage and the counting grid is 

brought into focus at low power. 

It is essential to be extremely careful with higher power objectives, since the counting 

chamber is much thicker than a conventional slide. The chamber or an objective lens may be 

damaged if the user is not not careful. One entire grid on standard hemacytometers with Neubauer 

rulings can be seen at 40x (4x objective). The main divisions separate the grid into 9 large squares 

(like a tic-tac-toe grid). Each square has a surface area of one square mm, and the depth of the 

chamber is 0.1 mm. Thus the entire counting grid lies under a volume of 0.9 mm-cubed. 

Suspensions should be dilute enough so that the cells or other particles do not overlap 

each other on the grid, and should be uniformly distributed. To perform the count, determine the 

magnification needed to recognize the desired cell type. Now systematically count the cells in 

selected squares so that the total count is 100 cells or so (number of cells needed for a statistically 

significant count). For large cells this may mean counting the four large corner squares and the 

- 178 -


middle one. For a dense suspension of small cells you may wish to count the cells in the four 1/25 

sq. mm corners plus the middle square in the central square. Always decide on a specific counting 

patter to avoid bias. For cells that overlap a ruling, count a cell as "in" if it overlaps the top or right 

ruling, and "out" if it overlaps the bottom or left ruling. 

Here is a way to determine a particle count using a Neubauer hemocytometer. Suppose 

that you conduct a count as described above, and count 187 particles in the five small squares 

described. Each square has an area of 1/25 mm-squared (that is, 0.04 mm-squared) and depth of 

0.1 mm. The total volume in each square is (0.04)x(0.1) = 0.004 mm-cubed. You have five 

squares with combined volume of 5x(0.004) = 0.02 mm-cubed. Thus you counted 187 particles in 

a volume of 0.02 mm-cubed, giving you 187/(0.02) = 9350 particles per mm-cubed. There are 

1000 cubic millimeters in one cubic centimeter (same as a milliliter), so your particle count is 

9,350,000 per ml. 

Cells are often large enough to require counting over a larger surface area. For example, 

you might count the total number of cells in the four large corner squares plus the middle 

combined. Each square has surface area of 1 mm-squared and a depth of 0.1 mm, giving it a 

volume of 0.1 mm-cubed. Suppose that you counted 125 cells (total) in the five squares. You then 

have 125 cells per 0.5 mm-cubed, which is 250 cells/mm-cubed. Again, multiply by 1000 to 

determine cell count per ml (250,000). 

Sometimes you will need to dilute a cell suspension to get the cell density low enough for 

counting. In that case you will need to multiply your final count by the dilution factor. For example, 

suppose that for counting you had to dilute a suspension of Chlamydomonas 10 fold. Suppose you 

obtained a final count of 250,000 cells/ml as described above. Then the count in the original 

(undiluted) suspension is 10 x 250,000 which is 2,500,000 cells/ml. 

- 179 -


Mechanism of Mycoparasitism and Antibiosis 

Roopali Sharma, Smita Puri and Rashmi Tewari 


The activities of biocontrol agents mainly depends on different physiological environmental 

conditions to which they are subjected. For this reason, biocontrol exerted by BCAs is sometimes 

unpredictable. Understanding their mechanisms of biocontrol will lead to improved application of 

the different strains as biocontrol agents. These mechanisms are complex and what has been 

defined as biocontrol is the final result of different mechanisms acting synergistically to achieve 

disease control. Biocontrol results either from competition for nutrients and space or as a result of 

the ability of biocontrol agents to produce and/or resist metabolites that either impede spore 

germination (fungistasis), kill the cells (antibiosis) or modify the rhizosphere, e.g., by acidifying the 

soil, so that the pathogen cannot grow. Biocontrol may also results from a direct interaction 

between the pathogen itself and the biocontrol agent, as in mycoparasitism, which involves 

physical contact and synthesis of hydrolytic enzymes, toxic compounds and/or antibiotics that act 

synergistically with the enzymes. Trichoderma sp. can even exert positive effects on plants with an 

increase in plant growth (mineralization) and the stimulation of plant defense mechanisms. 

Mechanism of disease suppression may be due to competition, antibiosis or mycoparasitism. 

Mycoparasitism 

When one fungus parasitizes another, the phenomenon is called mycoparasitism, 

hyperparasitism, direct parasitism or interfungus parasitism. Mycoparasitism, the direct attack of 

one fungus on another, is a very complex process that involves sequential events, including 

recognition, attack and subsequent penetration and killing of the host. Almost all taxonomic groups 

of fungi are found to be involved in this phenomenon and often species within the same genus 

(e.g. Pythium) interact as host and parasite. Some examples of mycoparasitism in reference to 

biological control of diseases are the following. 

1. Trichoderma sp., mainly T. harzianum, is one of the most common mycoparasitic fungi. 

Trichoderma spp. parasitize a range of other fungi. The events leading to mycoparasitism 

are complex, and take place as follows: first, Trichoderma strains detect other fungi and 

grow towards them; remote sensing is at least partially due to the sequential expression of 

cell-wall degrading enzymes. Different strains can follow different patterns of induction, but 

the fungi apparently always produce low levels of an extracellular exochitinase. Diffusion of 

this enzyme catalyses the release of cell wall oligomers from target fungi, and this in turn 

indicates the expression of fungitoxic endochitinases, which also diffuse and begin to 

attack on the target fungus before contact is actually made. Once the fungi come into 

contact, Trichoderma spp. attach to the host and can coil around it and form appressoria 

(=specialized pressing organs from which a minute infection peg can grow and infect a cell) 

on the host surface. Attachment is mediated by the binding of carbohydrates in the 

- 180 -


Trichoderma cell wall to lectins (proteins having high affinity towards the carbohydrates) 

on the target fungus. Once in contact, the Trichoderma produce several fungitoxic cell-walldegrading 

enzymes, and probably also peptaibol antibiotics. The combined activities of 

these compounds result in parasitism of the target fungus and dissolution of the cell walls. 

At the sites of the appressoria, holes can be produced in the target fungus, and direct entry 

of Trichoderma hyphae into the lumen of the target fungus occurs. There are at least 20-30 

known genes, proteins and other metabolites that are directly involved in this interaction, 

which is typical of the complex systems that are used by these fungi in their interactions 

with other organisms. 

Scanning electron micrograph of the surface of hyphae of the plant pathogen Rhizoctonia solani 

after mycoparasitic Trichoderma hyphae were removed. Erosion of the cell wall due to the activity 

of cell wall degrading enzymes from the biocontrol fungus is evident, as are holes where the 

mycoparasitic Trichoderma hyphae penetrated the R. solani (photo courtesy of Ilan Chet, Hebrew 

University of Jerusalem). 

2. Sevearl yeasts, for example, Pichia guilliermondii, also parasitize and inhibit the growth of 

Botrytis, Penicillium, and other plant pathogenic fungi. 

3. Fungal plant pathogens that develop sclerotia are difficult to control as these propagules 

persist for long periods in soil. Several fungi which invade sclerotia and act as 

mycoparasite have now been identified. One of the most interesting is Sporidesmium 

sclerotiorum, which obligately parasitizes sclerotia of five important pathogens, Sclerotinia 

sclerotiorum, S. minor, S. trifoliorum, Selerotium cepivorum and Botrytis cinerea. Spores of 

this mycoparasite added in sufficient quantities have been shown to give good control of 

- 181 -


diseases such as lettuce drop caused by Sclerotinia minor. After infection, glucanose 

activity in the sclerotia increases, resulting in the production of glucose, which is readily 

assimilated by the mycoparasite and allows growth of germ tubes out of the sclerotium and 

into the soil for a distance of up to 3 cm. Other sclerotia within this radius are infected. 

Exploitation of this property by disking in inoculums of spores of the fungus resulted in 53 

per cent control of lettuce drop caused by S. minor. Another sclerotial parasite, 

Conyothirium minitans, has also been demonstrated biological control potential, but only 

when added to soil at high inoculums rates. 

Antibiosis 

Antibiosis is that antagonistic condition in which there is suppression of pathogenic 

microorganisms due to secretion of toxic or inhibitory compounds (antibiotics) by other 

microorganisms. Such compounds range from hydrogen cyanide (HCN) to enzymes and the 

microorganisms involved are often species of Trichoderma and Gliocladium among fungi, and 

Bacillus and Pseudomonas among bacteria. The pioneer work on the isolation and identification of 

antibiotic compounds from BCAs concerned are those synthesized by fungal antagonists. For 

instancei. 

Ghisalberti et al. (1990) isolated two pyrone antibiotics from the isolates of Trichoderma 

harzianum that suppressed take all disease of wheat (Gaeumanomyces graminis f. sp. tritici). 

ii. Inhibition in the growth of plant pathogenic fungi (Rhizoctonia solani, Phoma betae and 

Pythium ultimum) by Laetisaric aravilis, a basidiomycete, has been observed in both 

laboratory and field trials; the inhibitory substance has been a long chain fatty acid called 

laetisaric acid. 

Many antibiotics have been isolated and characterized from Trichoderma. These include 

gliotoxin, gliovirin and glioviridin from T. virens. and viridin, alkyl pyrones, isonitriles, polyketides, 

peptaibols, diketopiperazines, sesquiterpenes and some steroids from other Trichoderma spp. 

Bacteria BCAs are known to produce most diverse range of antimicrobial compounds. Bacillus 

subtilis effectively controls Rhizoctonia solani in many crops by producing bacilysin and 

fengymycin. Bacilysin inhibits yeast and bacteria and fengymycin inhibits filamentous fungi. In 

1994, however, zwittermicin A antibiotic has been obtained from Bacillus cereus strain UW 85, 

another successful biological control agent of damping off and root rot of soybean (Phytophthora 

sojae). The first commercial BCA was probably strain K84 of Agrobacterium which has been used 

successfully to control crown gall disease by Agrobacterium tumefaciens by agrocin 84 antibiotic. 

Strains of Pseudomonas produce several toxic inhibitory compounds including phenazine-1- 

carboxylic acid, phenazine-1-carboxamide, anthranilic acid, diacetyl phloroglucinol, pyoluteorin, 

pyrrolnitrin and viscosinamide. 

- 182 -


Some antibiotic products of BCAs, their class, source microorganism and target 

microorganism. 

Class of 

compound 

Antibiotic product Source microorganism Target 

microorganism 

Amino acid Basilycin Bacillus subtilis Yeasts and 

derived 

Bacteria 

Aminopolyol Zwittermicin A Bacillus cereus Fungi 

Cyanide HCN Pseudomonas fluorescens Fungi 

Enzymes chitinase Serratia marcescens Fungi 

Fatty acid Laetisaric acid Laetisaria arvalis Fungi 

Furanone 

Lipopeptide 

3-(1-hexenyl)-5- 

methyl-2- 

Iturin, 

Surfactin, 

Viscosin amide 

Pseudomonas aureofaciens Fusarium spp. 

Pythium ultimum, 

Rhizoctonia solani, 

Thielaviopsis 

basicola 

Bacillus subtilis, Bacillus subtilis, 

Pseudomonas fluorescens DR 

54 

Nicotinic acid 2-methylheptyl Streptomyces sp. 

derived 

isonicotinate 

Nucleotide Agrocin 84 Agrobacterium strain K 84 

Agrobacterium strain K 1026 

Peptide Dimerum (a Trichoderma virens, 

siderophore) Brevibacillus brevis 

Gramicidin S 

Phenazine Phenazine-1- Pseudomonas fluorescens, 

carboxylic acid, Pseudomonas chlororaphis PCL 

Phenazine-1- 1391 

Phenol 

carboxamide 

Anthranilic acid, 

Diacetylphloroglucinol, 

Flavipin, 

Pyoluteorin 

Pseudomonas fluorescens, 

Pseudomonas fluorescens, 

Epicoccum nigrum, 

Pseudomonas fluorescens 

Fungi and 

Bacteria, 

Fungi and 

Bacteria, 

Pythium ultimum 

Rhizoctonia solani, 

Fusarum spp. 

Agrobacterium 

tumefaciens 

Fungi 

Botrytis cinerea 

Gaeumannomyces 

graminis f.sp. tritici 

Gaeumannomyces 

graminis f.sp. 

tritici, 

Monilia laxa, 

Pythium ultimum, 

Piperazine Gliotoxin Gliocladium virens Fungi 

Pyrone 6-pentyl-α-pyrone Trichoderma spp. Gaeumannomyces 

graminis f.sp. tritici 

Peptaibols 

Trichozianins, 

trichokindins, 

trichorzins, 

harzianins, 

trichogins etc 


Phenyl-pyrrole Pyrrolnitrin Pseodomonas spp. Fungi 

Inhibit a number of 

fungi and gram 

positive bacteria 

- 183 -


Mass Production and Formulation Technology of Trichoderma 

Roopali Sharma and Bhanu Pratap Bhadauria 


Materials required: Barnyard millet (jhangora), 250 ml Erlenmayer flasks, inoculating 

needle, Trichoderma culture, Talcum powder, CMC, Sieves, Grinder, Polypropylene bags 

Mass multiplication of Trichoderma isolates 

Barnyard millet (jhangora) grains are used to prepare pure powder of Trichoderma. 

1. Wash and soak the grains in water for 12 h and then filled in 250 ml Erlenmeyer flasks (@ 

100g/ flask) or in half kg polypropylene bags (150 grains/bag). 

2. Plug the flasks and bags with non absorbent cotton plug (with the help of neck). 

3. Autoclave at 20 lbs psi. for 20 min. 

4. After cooling to room temperature, inoculate the flasks or bags with 4-6 discs of actively 

growing culture of Trichoderma harzianum. 

5. Incubate the bags at 28 ° C for 10-12 days and shake at regular intervals. 

6. The colonized grains turn green with sporulation. 

7. After 12 days, the colonized grains are emptied into plastic trays and dried under shade for 

4-5 days. 

8. The dried colonized grains are then ground with the help of Willey Mill or normal grinder to 

get a powder. 

9. This powder is then sieved through a normal coarse (50 mesh size) and fine (80 mesh 

size) sieves, simultaneously to obtain a very fine pure powder. 

10. This pure powder is then mixed with talcum powder in a ratio of 10 g pure powder + 1kg 

Talcum powder (commercial grade ) get the commercial formulation. The shelf life of the 

formulation is for four months under room temperature and six months under controlled 

conditions. 

11. 10% Carboxy Methyl Cellulose (CMC) is also added as a sticker. 

- 184 -


Identification of Pseudomonas and Bacillus isolates using Biolog 

System 

J.Kumar, Roopali Sharma, Smita Puri and Kahkashan Arzoo 


In recent years, popular methods for studying plant pathogens community structure were 

based on the analysis of phospholipid fatty acids (PLFA) or denaturing/temperature gradient gel 

electrophoresis (DGGE/TGGE) etc. The above-mentioned methods are based on molecular 

assays. Measurements of physiological activity of microorganisms represent another approach, 

allowing the study of different characteristics of microbial communities. The Biolog technique is 

one of the methods which rely on measurements of utilizing different carbon substrates by 

microorganisms. Measurements of substrate use enable qualifying microbial metabolic capabilities 

and hence functional diversity of a microbial community. 

The Principle of the Biolog Method - The Biolog plate’s method was first used to compare 

metabolic activity of heterotrophic microbial communities from different habitats such as water, soil 

and wheat rhizosphere. The technique is based on a redox system. Various types of plates are 

used, but Biolog GN plates for gram-negative bacteria are the most popular ones. Biolog Microbial 

Identification System is based on metabolic phenotypes. Biolog plates are plastic microtiter plates 

containing 95 different carbon substrates in wells, and no substrate in one well which is used as 

control. Among the 95 substrates one can distinguish a few groups of chemical compounds, for 

example, carbohydrates, amino acids, carboxylic acids, amines, amides and polymers. Biolog is 

based on the theory that a species of bacteria develops a unique metabolic finger-print on a set of 

carbon sources and biochemicals. The cultured bacteria are tested for utilization of different 

carbon sources and biochemicals, which are pre-filled and dried into a 96 well test plate. 

Additionally, each well contains a colourless Tetrazolium redox dye, used to colorimetrically 

indicate utilization of the substrates. Cells utilizing nutrient, respire and release energy which 

reduces proprietary Tetrazolium dye to form a distinct purple colour. Biolog data collection 

software is used to record the unique metabolic profile into the computer which can be compared 

with thousands of profiles (corresponding to thousands of species) stored in the Biolog databases. 

If the profile is matched, computer displays the identified species. 

Biolog has designed proprietary microplates for identification of a wide range of microbes 

up to species level, such as Gen III plate (for gram negative and gram positive aerobic bacteria), 

AN plate (for anaerobic bacteria), YT plate (for yeast) and FF plate (for filamentous fungi). Nearly 

2550 species are covered by Biolog for identification. 

Application- It has been used for clean room analysis of microbial identification prevalent in 

environment, industrial quality control in analysis of food and/or agricultural products, plant disease 

diagnosis, veterinary, analysis of clinical samples including dangerous pathogens of human, 

animal and plant origin, education and research involving general and applied microbiology. 

- 185 -


Different types of Biolog plates- The Biolog GNplates have been designed for identification of 

gram negative bacteria and contain substrates appropriate for this group of microorganisms. 

Analogically, the GP plates are adapted for identification of gram positive bacteria. Two types of 

Biolog plates are available i.e. GEN II and GEN III. Microbial identification for GEN II MicroPlates 

involves five basic steps (identification process for AN, YT, or FF) while GEN III plates involves in 

four basic steps. These steps apply to all identifications. A small number of species have 

peculiarities that may require an extra step or special handling techniques. 

The Microbial Identification Process for GEN II MicroPlates 

Step 1: Isolation of a pure culture - As a first step to accurate microbe identification, streak agar 

plates using correct techniques to generate well isolated colonies. Always use Biologrecommended 

culture media and growth conditions. 

Step 2: Gram staining and determining test protocol- For bacteria, proper Gram stain 

technique and interpretation are the important second step in the ID process identification; use the 

wet prep test as necessary to differentiate yeasts from filamentous fungi. 

Step 3: Prepare inoculum at specified cell density- Determine cell density using Colorimeter. 

Cell density describes oxygen concentration a key parameter to control when testing 

microorganisms in MicroPlates. Additionally, Biolog has carefully optimized the required 

inoculating fluids and standards. 

Step 4: Inoculate and incubate MicroPlate- Pipette the specified amount of cell suspension into 

the MicroPlate, put the lid on, and incubate under the same conditions of temperature and 

atmosphere used to culture the microorganism. Biolog MicroPlates do not need oil overlays or 

color-developing chemicals. 

Step 5: Read MicroPlate and determine ID- After an appropriate incubation time, read 

MicroPlates either by eye or using the MicroStation Reader. In either case, the pattern formed in 

the wells is entered into the software, which searches the database and provides identification in 

seconds. 

Data is fed into a software enabled computer which performs analysis and reports the 

species of the isolated micro-organism. 

‣ A large sized database is comprised of ~2550 species of which ~700 are of clinical 

importance. 

‣ Gen II Microplate can be used to identify 1350 species of aerobic bacteria. 

‣ AN Microplate can be used to identify 361 species of anaerobic bacteria. 

‣ YT Microplate can be used to identify 267 species of yeast. 

‣ FF Microplate can be used to identify 619 species of filamentous fungi (619 species). 

‣ GN2 Microplate can be used to identify species of gram negative bacteria. 

‣ GP2 Microplate can be used to identify species of gram positive bacteria. 

Technology can be used in manual, semi-automatically or fully automatically as per the 

- 186 -


researcher’s variable needs and budget. 

Gen III Microstation System (Most preferred system)- GEN III Microstation is a semi-automated 

microbial identification system. It is Plate reader which is linked to a computer configured with 

software related to data collection and microbial identification software. It is capable of reading all 

types of Biolog Microplates. A microplate loaded with suspension of a test organism is incubated in 

a user-provided incubator and read using Microstation. The metabolic finger print is read and sent 

to the computer for recording and eventual comparative studies with profiles already stored in 

Biolog databases. Computer reports the species/genus when the metabolic finger print is matched 

with those present in Biolog Database. The system is capable of identifying aerobic bacteria, 

anaerobic bacteria, yeast as well as filamentous fungi. 

System Benefits- No Gram stain is needed. One test panel IDs for both GN and GP bacteria. Setup 

time in under a minute, accurate results in as little as 4 hours, Powerful RetroSpect software for 

trending and tracking. 

Gen III Omnilog Id System (Preferred system for handling a large number of samples)- Gen III 

Omnilog Id System is an automated microbial identification system. It is provided along with Omnilog 

which is Plate reader cum Incubator. It is linked to a computer configured with software related to 

data collection and microbial identification software. A microplate loaded with suspension of test 

organism is incubated and read in Omnilog. The metabolic finger print is read and sent to the 

computer for recording and eventual comparative studies with profiles already stored in Biolog 

databases. Computer reports the species/genus when the metabolic finger print is matched with 

those present in Biolog Database. Omnilog can accommodate 50 Microplates simultaneously, with 

recording of the metabolic finger-print at 15 minutes interval in real-time thus making the microbial 

identification automated and high throughput. The system is capable of automated identification of 

aerobic bacteria only. It can be upgraded to undertake Phenotype Microarray. 

Gen III Omnilog Plus Id System- The system is capable of automated identification of aerobic 

bacteria, and rapid identification of anaerobic bacteria, yeast as well as filamentous fungi. 

Gen III Microlog M System (Manual System)- Microlog M is the Manual Version of Biolog’s 

Microbial Identification System. It uses the same Gen III plate and Gen III Microbial Identification 

software, as are used in automated systems. Difference is that Computer and Plate Reader, are 

not provided in Manual System. Microbial culture is used to inoculate the Gen III plate, which is 

then incubated in a lab incubator. Plate is read for all the 96 tests manually in terms of Positive or 

Negative reaction (If color appears, it is positive otherwise negative). The plate results (positive or 

negative), are fed manually in Gen III software which is provided and loaded in a user provided 

computer. Software does the analysis, searches Biolog provided database, and then reports the 

species. You can also update the database with those genus/species which are not present in 

Biolog database (using an optional Retrospect). Manual system can be used for only aerobic 

bacteria. 

- 187 -


Biochemical Tests for Identification of Bacterial Pathogens 

Yogendra Singh and Bhupendra Singh Kharayat 


The identification and classification of bacteria are of crucial importance in environmental, 

industrial, medical and agricultural microbiology and microbial ecology. A number of different 

phenotypic and genotypic methods are presently being employed for microbial identification and 

classification. Each of these methods permits a certain level of phylogenetic classification, from the 

genus, species, subspecies, biovar to the strain specific level. Moreover, each method has its 

advantages and disadvantages; with regard to ease of application, reproducibility, requirement for 

equipment and level of resolution. 

Gram Staining 

Requirements 

 

 

 

Protocol 

24 h old culture of test bacterium 

Slides, light microscope, glass rods, cotton, vim powder, blotting sheets, tap water 

Hucker’s crystal violet stain, safranin, 95% alcohol, iodine solution 

1. Take a loopful of the test organism. 

2. Spread on a clean slide and allow it to air dry. 

3. Gently heat to fix the smear. 

4. Cover the smear with crystal violet for 1 minute. 

5. Flash wash in running water for a few seconds. 

6. Rinse the smear with iodine and cover for 1 minute. 

7. Rinse the slide in running water. 

8. Decolorize with alcohol (95%) drop wise till the dye does not run off the smear. 

9. Rinse with water. 

10. Cover the smear with counter stain safranin for 30 seconds. 

11. Rinse with water and blot dry. Observe under oil immersion lens. 

Observation 

The gram positive cells stain purple and the gram negative cells stain red. 

KOH Confirmatory Test/ Solubility Test 

Requirements 

 

 

 

Protocols 

 

Test bacterial culture of 24 h growth. 

Potassium hydroxide (3% aq., w/v) 

Inoculation loop, glass slides 

With the help of a pipette place a drop of KOH on clean slide. 

- 188 -


With sterile loop remove a part of a single, well- separated colony from a young actively 

growing culture. 

Mix the culture into the KOH until an even suspension is obtained. 

Lift the loop from the slide and observe. 

Observation 

If a string of slime is lifted with the loop, the bacterium is Gram negative. If a watery 

suspension is produced and no string of slime observed, the culture is Gram positive. 

Catalase Production test 

Requirements 

Test bacterium 

Hydrogen peroxide (H 2 O 2 ) 

Glass slide 

Protocols 

Smear a loopful of 24-48 hr slant growth on a slide 

Cover it with a few drop of hydrogen peroxide 

Observation: Production of gas bubbles (O 2 ) indicates a positive reaction. 

Test for H 2 S production 

Requirements 

Test bacterium 

Strips of filter paper (Whatman No. 42) 

Lead acetate 

Protocols 

Take strips of filter paper (Whatman No. 42) impregnated with lead acetate solution 

Air dry the strips and autoclave them 

Keep autoclaved strips inside the slants inoculated with the bacterial isolate, one end of 

the strip is held by the cotton plug and the other end is free and hanging. 

Incubate at 28 0 C for 3 days. 

Observation 

Blackening of strip indicates a positive reaction. 

Medium for production of H 2 S 

Peptone: 10 g 

NaCl: 5 g 

Water: 1000 ml 

Agar 20g 

pH: 7.0 

Citrate test 

Simmons Citrate Agar is used for the differentiation of gram negative bacteria on the basis of 

- 189 -


citrate utilization. 

Medium 

Ammonium Dihydrogen Phosphate 1.0g 

Dipotassium Phosphate 1.0g 

Sodium Chloride 5.0g 

Sodium Citrate 2.0g 

Magnesium Sulfate 0.2g 

Agar 15.0g 

Bromthymol Blue 0.08g 

Distilled water 

1000ml 

Protocol: 

Dispense the medium and autoclave at121 0 C for 15 minutes 

Allow to cool in a slanted position for use as slants. Medium may also be used for plating 

Inoculate slants with growth from a pure culture 

Incubate for 4 days at 35±2 0 C. 

Observation: Growth with blue colour in the slants indicates a positive reaction whereas 

negative reaction is evidenced by no to trace growth with original dark green medium (no 

change in colour). 

Oxidase Test 

Impregnated disk method 

In this method reagent impregnated disks are used. 

Wet the disks with de-ionized water using inoculating loop 

With the help of loop aseptically transfer a large mass of pure bacteria to the disk 

Observe the disk for colour change. If the area of inoculation turns dark blue, the result 

is positive 

Precautions: Perform the oxidase test on fresh cultures. Using older cultures may yield 

unexpected results. The colour change should occur within the first 30 seconds. Disregard any 

colour change after this time period. Do not use a nichrome loop as this may lead to a false 

positive result. 

Logan’s Differential Medium for Erwinia 

The medium was developed by Logan in 1966 to distinguish E.carotovora pv. atroseptica 

from pv. carotovora. E.carotovora pv. carotovora reduces the tetrazolium to insoluble red formazan 

and colonies (about 1.5 mm dia.) develop a pink to red/purple colour. 

Nutrient agar 

28.0 g 

Yeast extract 

5.0 g 

Glucose 5.0g 

Water 

1000 ml 

- 190 -


After autoclaving, the medium is cooled to 60 0 C and 10 ml of filtered-sterilized 0.5% 

solution of 2,3,5-tri phenyl tetrazolium chloride added. 

Suggested readings 

• Janse, J. D. 2006. Phytobacteriology principles and practice.366p. 

• Schaad, N.W.; Jones, J.B. and Chun, W. 2001. Laboratory Guide for Identification of 

Plant Pathogenic Bacteria. 3rd edn. St Paul, MN, USA: APS Press.158. 

- 191 -


Visit to Meteorological Observatory and Automatic Weather Station in 

Cropped Field at N.E.B. CRC 

Introduction 

H. S. Kushwaha 


Since the meteorological instruments in the meteorological observatories are exposed 

over the short cut grass, apparently the values of some of the important weather variables 

especially the air temperature, relative humidity, leaf wetness and the wind in particular may 

differ significantly from those observed in a cropped field. The major meteorological instruments 

available at meteorological observatory included Stevension screen to house maximum 

thermometer, minimum thermometer, dry bulb thermometer and wet bulb thermometer, three soil 

thermometers each at 5, 10 and 20 cm soil depth, USWB Class A open Pan evaporimeter, 

Ordinary & self recording rain gauges, Anemometer, Wind vane, Bright Sunshine recorder, dew 

gauge etc. The data is recorded daily twice a day at 0712 hrs and at 1412 hrs at Pantnagar by 

IMD trained meteorological observers and record is maintained in pocket registers supplied by 

IMD. However, the validity of such weather data recorded at meteorological observatory at a 

location from a field experiment will decrease with 

the distance from the meteorological 

observatory. Keeping in view this constraint, for disease-weather relationship it is, recommended 

& advised to monitor these important weather variables over and within the crops under natural 

field conditions. These fields have variability in terms of crops their type and stage, soil 

moisture, ground water table, tillage operations for soil manipulation etc. as compared with the 

meteorological observatory field. Also detailed and reliable weather information is also not 

available in many locations in the country due to non-availabilty of meteorological observatories. 

For this purpose, a Scientific Automatic Weather Station (AWS) attached with micrologger and 

Computer will be very useful for recording of weather parameters within and over the crops 

accurately and then correlate them with crop observations for understanding the real crop - 

weather relationships in general and disease - weather relationships in particular for major crops 

of the area. There is a close relationship between crop diseases and weather variables and, 

therefore, under prevailing weather conditions, the incidence of several diseases may occur in an 

area and the application of chemicals in these crops will depend on the intensity and durability of 

the weather conditions prevailing at particular and sensitive crop stage. The details of observations 

are given below : 

A. Meteorological observatory 

A plain area of 55 m (N-W) x 36 m (E-W) size with short cut grasses free from all 

obstacles including highway, high building, big trees, canals, rivers and wild animals provides a 

good exposure for installing all the meteorological instruments in the observatory. If a person 

stands at the gate facing the observatory plot, he will find the tall instruments in the back row and 

- 192 -


shorter instruments in the front rows. In general the instruments are separated at a distance of 9 m 

from each within rows of 12 m apart. All observations are taken manually by meteorological 

observer daily twice a day. 

B. Automatic weather station (AWS) 

A Campbell Scientific Automatic Weather Station has been designed and developed to a 

very high standard for reliable measurement and recording of wide range of important 

micrometeorological variables in and above the crops The station is soundly engineered and 

based Campbell,s proven 21X micrologger whose comprehensive specification enables the user 

to undertake virtually any monitoring task. The main and important features of the system are 

described as below: 

1. Wide range of sensors: A maximum of 20 sensors can be a attached to this at a time. 

2. Flexible data storage: It has Internal memory to store 19, 200 data points i.e. hourly data for 

continuous 40 days at a time can be stored. 

3. Versatile data transfer: Software package is available for automatic routine collection of data 

at pre determined time interval which can be modified as per the need and requirement. 

4. Fully protected: It has a weather proof enclosure to protect data logger and peripheral against 

dust and moisture. The logger can operate over the range from - 25 o C to + 50 o C without any 

error. 

5. Integral data processing: The processing includes the averages of maximum and minimum 

averages of all weather variables, standard deviations, wind vector integration etc. 

6. Robust construction: Tripod and mast are build from thick walled, galvanished steel tubing 

with nickle-plated fittings. The mast is 3 metre in height with adjustable cross-arm supports for 

sensors. The mast can be positoned precisely by independently adjusting tripod legs. Each leg is 

provided with a flat foot with 12 mm hole which allows anchorage to the ground by stake or to 

concrete. A lightning conductor and earth spike are also included to save the sensors and 

datalogger from destructive effects of Thunderstorm and Lightning as and when experienced in the 

area. For measurement of weather parameters in and over the Horticutural crops, a mast of 30 

metre height (existing in the nearby site in the same field) can be used for sitting the sensors at 

desired heights depending upon the height of horticultural crops as per the need and requirement. 

7. Minimum maintenance: Once errected, the station requires very little routine attension. 

8. Recording device 

It has a 21 X Micrologger as recording device. It is a rugged field-proven datalogger 

suitable for any application requiring data acquisition, on line data processing or electronic control. 

It is compact and powerfull battery-powered device which effectively combines the functions of 

micro-computer, clock, calibrator, scanner, frequency counter and controller with one smaller 

enclosure. The 12 volt Nickle-Cadmium battery is chargeable by solar pannel. The micrologger is 

programmed to handle almost any task including signal averaging, exite and delay, totaling, 

- 193 -


maximum and minimum, standard deviation, scaling, 5th order polynomial processing, low-pass 

filtering and wind vector calculation which are fully supported by simple program statements, 

together with a histogram command for direct calculation of frequency distributions. Software 

support is available to simplify more complex programming tasks and to avoid inspection and 

processing of stored data. 

Structure, Functioning and Sitting of Various Micro-meteorological Sensors on Automatic 

Weather Station 

This Automatic Weather Station (AWS) is composed with various micrometeorological 

instruments / sensors for monitoring the micrometeorological weather variables such as Air 

temperature ( o C), Relative humidity (%), Wind speed (m s -1 ), Wind direction (degrees from North), 

Leaf temperature ( o C), Leaf wetness ( % of total wet), Solar radiation (W m -2 ), Net radiation (W 

m -2 ), Rainfall (mm) , Soil temperature ( o C) etc. within and above the crop canopy. A brief 

description of sensors measuring these weather variables is given under the following subheads: 

1. Air temperature and relative humidity: 

The air temperature and relative humidity in and above crop canopy are measured by HMP 

35 AC Temperature and Relative Humidity (RH) probes (two sensors). The probe contains a 

Vaisala capacitive relative humidity sensor and a precision thermistor. The probe is designed to be 

housed in a 41004-5 or URSI radiation shield and is attached with a 3 m long lead wire and 

a connector. The length of lead wire can be increased as per the requirement. 

2. Wind speed: 

Wind speed in and above crop canopy is measured by A100R Switching Anemometer 

(two sensors) in which a magnet rotates with the rotor spindle. The varying field forces a mercury 

wetted reed switch to make contact once per resolution. This instrument is a precision instrument 

which is easily interfaced with Datalogger to give accurate measurements of wind run or mean 

wind speed in m/s. This instrument is constructed from anodised aluminium alloy, stainless steels 

and weather resisting plastics. A stainless steel shaft runs in two precision, corrosion-resistant ball 

races. The bearings are protected from the entry of moisture droplets and dust, resulting the 

instrument suitable for permanent exposure to the weather. Its sensitivity is 0.80 revolutions per 

metre with an overall accuracy of 2 % + 0.1 m s -1 . 

3. Wind Direction 

The wind direction at 3 m height is measured by W200P Potentiometer Wind Vane (one 

sensor). This instrument is manufactured by Vector Instruments Ltd. and measures the wind 

direction directly in degrees from North. The windvane incorporates a 358 degree micro - torque 

potentiomter (wire wound type). The 2 degree gap is filled to ensure operation and a long service 

life. The precision ball - bearing races are corrosion - resistant and are protected against the entry 

- 194 -


of moisture and dust. 

4. Leaf Temperature 

The temperature ( o C) of leave is measured by K-Type Thermocouples (two sensors). 

Copper and constantan thermocouple wires were twisted to form the sensors and are connected 

to the leaves of the plants. There is provision of adding two more leaf temperature sensors. 

5. Soil Temperature: 

The soil temperature ( o C) at 10 and 20 cms soil depths are measured by 107 Thermister 

Probes (two sensors). These probes incorporate a precision thermistor in a water resistant probe 

with a standard 3 m long cable. 

6. Leaf Wetness Period 

The duration of leaf wetness at crop surface is measured by 237 Wetness Sensing grid. 

This grid is suitable for a range of Scientific and Industrial wetness sensing applications. It 

provides a simple measure of the degree of wetness of the surface to which they are attached / 

exposed and they can also be used to measure the percentage of time for which the surface is wet 

or dry. The sensor consists of a rigid epoxy circuit board (75 mm x 60 mm) with interlacing gold - 

plated fingers. Condensation or rain on the sensor lowers the resistance between the fingers 

which is measured by the datalogger. 

7. Solar Radiation 

The Solar or Global radiation at 3 m height is being measured by SP1110 Pyranometer 

sensor (one sensor). This is a compact high - output thermally stable solar radiation sensor. The 

cosine- errected head contains a special high grade Silicon Photocell sensitive to short-wave 

radiation with wavelength between 350 and 1100 nm. The head is completely sealed and can be 

left indefinitely in exposed conditions. A levelling mount is also available which enables the 

pyranometer to be accurately positioned. The output is 10 mv / 1000 W m -2 with excellent linearity. 

8. Net Radiation: 

The net radiation which is the difference between the incomming solar radiation and the 

outgoing radiation received on the crop surface is being measured by Q -7 Net Radiometer (one 

sensor). This instrument is high - output thermopile sensor which measures the algebraic sum of 

incoming and outgoing all - wave radiation (i.e. short- and long - wave components). Incoming 

radiation consists of direct (beam) and diffuse plus long wave irradiance from the sky. Outgoing 

radiation consists of reflected solar radiation plus the terrestroal long-wave components. It consists 

60 - junction thermopile with low electrical resistance. The top and bottom surfaces are painted 

black and are protected from convective cooling by hemispherial heavy duty polyethelene 

windshileds. 

9. Rainfall 

The rainfall is measured by ARG 100 Aerodynamic Tipping Bucket Raingauge (one 

sensor). It is a well designed tipping bucket raingauge which combines durable construction 

- 195 -


with very reasonable cost. The gauge offers less resistance to air flow and helps to reduce the 

sampling errors that inevitably occur during wind - driven rain. This instrument is constructed from 

UV - resistant, vaccum - moulded plastic and consists of a base and an upper collecting funnel. 

The base splits into two parts, the inner section supporting the tipping - bucket mechanism and 

the outer providing protection and allowing the unit to be bolded firmly to a suitable mounting 

plinth or concrete slab. The gauge resolution is 0.2 mm / tip. the funnel diameter is 25.5 cms. 

10. Micrologger enclosure 

All the sensors and the logging equipment are supported on a sturly tripod and mast. A 

fiberglass housing with lock and key provides as excellent environmental protection for the 

datalogger and ancillary equipment. Glass fitted nylon water proof connectors are fitted to the base 

of the enclosure and sensors may be removed or replaced with minimum disturbance to the 

weather station. 

C. Recording & data logger programming in automatic weather station 

All these above sensors have been hooked into the 21X Micrologger (Datalogger) which 

runs through a chargeable battery charged with Solarex Solar Panels. In order to record the 

output of these sensors, a datalogger programme has been prepared in the Computer depending 

upon the number of the sensors attached with different channels in the datalogger and also the 

frequency and time of observations. This has been done with the help of micro -programmes 

developed in the Computer, and the output is converted into the desired units for each weather 

variable. Each variable is sensed after each minute and an integrated value over a period of five 

minutes is calculated. Twelves such values of each data point is totalled or averaged over a 

period of say one hour and is stored in the memory of the datalogger at an appropriate 

location at each hour of the day. The data is also averaged or totalled from each day called Julian 

day (i.e. the day of a year from Ist January) from the date of planting / sowing of the crop in the 

field. In the present study the recording of micrometeorological weather variables by AWS were 

started one month before the first sowing of potato crop and continued till the end of the Potato 

crop season. The crop var. Kufri Bahar which is sensitive to Late Blight of Potato was planted on 

25 - 10 – 2012. The observations on micro-meteorological variables in crop field since October 01, 

2012 and will continue till harvesting of crop of all planting dates depending upon the maturity of 

crop in March 2013. The incidence of Late Blight of Potato is monitored on day by day basis and 

will continue till maturity of crop in all plots. The recording of micro- meteorological data 

observations is also continuing till date. The current data of this hour can be noted on the provided 

sheet. At a time, the micro-meteorological data of last 40 days can stored in this datalogger and it 

can be seen on hourly basis on liquid crystal display (LCD) of the datalogger. 

From this data logger each week the micro-meteorological data thus stored in its memory 

is transferred into the SM 192 Storage Module by connecting it to the 9 - pin serial I / O port. This 

Storage Module is taken to the laboratory and connected to the Computer. From SM -192 using 

- 196 -


SC – 532, 9 - pin Peripheral to RS - 232 interface, the data is then transferred into the Computer 

in ASCII form using SMCOM programmes developed for this purpose in the form of a Computer 

file. From this file the data is then splitted into the hourly as well as into daily values using splitting 

programmes like SPLIT 03. PAR and SPLIT 04. PAR, respectively, which have also been 

development on Computer. The data will then be used for identification of micro-meteorological 

weather conditions conducive for the occurrence of late blight of potato during the 2009-10 

season. 

Data sheet for recording of current observations of micro-meteorological variables in the 

potato field AT CRC using automatic weather station 

The current micro-meteorological weather variables are being recorded by Automatic 

Weather Station (AWS) in the field from 01-10-2012 and the date of planting of Potato crop var. 

Kufri Bahar in plot is 25-10-2012 during this Rabi season of 2012 - 13 at Crop Research Centre of 

the University. The current data can be read on Liquid Crystal Display (LCD) of the Datalogger of 

the AWS in the table given below in the specific sequence of attached sensors: 

1. Name of the crop : Potato 2. Date of Ist planting of crop : 25-10-2012 

3. Stage of the crop : Tuber Formation 4. Julian day : 40 

5. Date of observation : 09-02-2013 6. Time of observation : 1600 hrs 

----------------------------------------------------------------------------------------------------------------------------------- 

S.No. LOCATION NO. WEATHER VARIABLE HEIGHT UNITS 

---------------------------------------------------------------------------------------------------------------------------------- 

1. 1 Relative Humidity 1 3m % 

2. 2 Air Temperature 1 3m 

3. 3 Relative Humidity 2 crop % 

4. 4 Air Temperature 2 crop 

5. 5 Net Radiation crop W m -2 

6. 6 Solar Radiation 3m W m -2 

7. 7 Soil Temperature 1 10 cm depth 

8. 8 Soil Temperature 2 20 cm depth 

9. 9 Leaf Wetness crop % 

10. 10 Wind Direction 3m Degrees 

11. 11 Wind Speed 1 3m m s -1 

12. 12 Wind Speed 2 crop m s -1 

13. 13 Rainfall crop mm 

14. 14 Leaf Temperature 1 crop 

15. 15 Leaf Temperature 2 crop 

o C 

o C 

o C 

o C 

o C 

o C 

- 197 -

ANNEXURE-I 

CENTRE OF ADVANCED FACULTY TRAINING IN PLANT PATHOLOGY 

College of Agriculture, Pantnagar-263 145 (Uttarakhand) 

Following committees have been constituted for smooth conduct of the training programme on 

“Managing Plant Microbe Interactions for the Management of Soil-borne Plant Pathogens” 

scheduled on January 22 to February 11, 2013. 

1. Overall Supervision 

Dr. K. Vishunavat, Director CAFTPP 

Dr. Yogendra Singh, Course Coordinator 

Dr. R.P. Singh, Co-course Coordinator 

Dr. R.P. Awasthi 

Dr. V.S. Pundhir 

Dr. K.S. Dubey 

3. Inaugural Session, Intersession Tea and 

valedictory function Committee 

Dr. K.P.S. Kushwaha – Chairman 

Dr. Bijendra Kumar 

Mr. S. P. Yadav 

5. Transport and Reception Committee 

Dr. Pradeep Kumar – Chairman 

Dr. S.K. Mishra 

Mr. B.C. Sharma 

7. Registration Committee 

Dr. K.P. Singh – Chairman 

Dr. (Mrs.) Deepshikha 

Dr. (Mrs.) Renu Singh 

9. Audiovisual Aid & Publicity Committee 

Dr. R.K. Sahu-Chairman 

Dr. Geeta Sharma 

Mr. Ajit Kumar 

2. Invitation, Inaugural and Closing 

Function Committee 

Dr. H.S. Tripathi– Chairman 

Dr. A.K. Tewari 

Mr. S.P. Yadav 

Mr. Mehboob 

4. Budget Committee 

Dr. R. P. Awasthi – Chairman 

Dr. Vishwanath 

Mr. O.P. Varshney (A.O.) 

Mr. A. B. Joshi 

Mr. Praveen Kumar 

Mr. Prakash Joshi 

6. Boarding & Lodging Committee 

Dr. V.S. Pundhir – Chairman 

Dr. R.P. Singh 

Dr. Mohan Singh 

Mr. Vikram Prasad 

8. Field / Excursion Trip Committee 

Dr. K.S. Dubey– Chairman 


Dr. Satya Kumar 

10. Committee for typing correspondence 

work 

Dr. A.K. Tewari, Chairman 

Smt. Meena Singh 

Mr. Gharbharan Prasad 

-i-

ANNEXURE-II 

LIST OF PARTICIPANTS 

Sl. 

No. 

Name and Address 

Phone/E-mail 

1. Shri. Y.M. Rojasara 

Assistant Research Scientist 

Bidi Tobacco Research Station 

Anand Agricultural University 

Anand- 388 110 (Gujarat) 

2. Dr. B. Anjaneya Reddy 

Assistant Professor, Plant Pathology 

College of Horticulture, NH-4 

Tamaka, Kolar- 563 101 (Karnataka) 

3. Dr. K.R. Shreenivasa 

Asstt. Professor-SMS (Plant Pathology) 

Krishi Vigyan Kendra, Navile 

Shimoga-577 225 (Karnataka) 

4. Shri. Umashankar Kumar N. 

Assistant Professor (Plant Pathology) 

Krishi Vigyan Kendra 

Univ. of Agricl. Sciences, Bangalore 

Mudigere- 577 132 (Karnataka) 

5. Shri. Raghavendra Achari 

Assistant Professor of Plant Pathology 

Horticulture Research Station 

Taluk and District Bijapur 

Tidagundi-586 119 (Karnataka) 

6. Dr. (Mrs.) K. Karuna 

Assistant Professor (SS) Pathologist 

AICRP (Sunflower) 

ZARS, UAS GKVK 

Bangalore- 560 065 (Karnataka) 

7. Dr. Vijay Bahadur Singh 

Assistant Professor/Jr. Scientist (Pl. Path.) 

Rainfed Research Sub-station for 

Sub-tropical Fruits, Raya 

S.K.U.A.S.T-Jammu-180 009 (J&K) 

8. Dr. Mohammad Ashraf Ahanger 

Assistant Professor 

Mountain Crop Research Station Sagam 

SKUAST-Kashmir, Anantnag- 192231 (J&K) 

9. Dr. (Mrs.) V. Bhuvaneswari 

Scientist (Plant Pathology) 

Andhra Pradesh Rice Research Institute & 

Regional Agricultural Research Station 

Maruteru- 534 122 (AP) 

(O): 02692-262061 

(Mb.): 09429159782 

E-mail: yogeshrojasara@gmail.com 

(O): 08152-243208 

(Mb.): 09844188834 

E-mail: arb_agri@yahoo.co.in 

(Mb.): 07259345526 

E-mail: shreenikr@rediffmail.com 

(O): 08263-228198 

(Mb.): 09739337172 

E-mail: umapathologist@gmail.com 

(O): 08352-235000, 235002 

(Mb.): 09448876730 

E-mail: achari_r@rediffmail.com 

raghavendra.achari@uhsbagalkot.edu.cin 

ars_tidagundi@rediffmail.com 

(O): 080-2330153 

(R): 080-23466136 

(Mb.): 9901513044 

E-mail: kavlikaruna@yahoo.co.in 

csl_narayan2003@yahoo.com 

(O): 09469211285 

(R): 09419274324 

(Mb.): 09797559776 

E-mail: vbsinghkhb@gmail.com 

(O): 01931238246 

(Mb.): 07298590079 

E-mail: agsamina@yahoo.com 

(O): 08819-246283, 214273 

(Mb.): 9441915094 

E-mail: bhuvanavk2001@gmail.com 

-i-

10. Dr. L. Rajendran 


Horticulture Research Station 

Vijayanagaram, TNAU,Ooty-643001(TN) 

11. Dr. V. Sendhilvel 



Tamil Nadu Agricultural Univerity 

Virinjipuram (TN) 

12. Dr. R.C. Shakywar 

Asstt. Prof. (Pl. Path. & Microbiology) 

Department of Plant Protection 

College of Horticulture & Forestry 

Central Agricultural University 

Pasighat- 791 102 (Arunachal Pradesh) 

13. Dr. Yogesh Vitthalrao Ingle 

Assistant Professor of Plant Pathology 

Regional Research Centre, Amravati 

(Dr. PDKV, Akola), Amravati- 444 603 (MS) 

14. Dr. Shlokeshwar Raj Sharma 

I/C Programme Coordinator SMS (Pl Prot.) 


J.N. Krishi Vishwa Vidyalaya, Jabalpur 

Piproud-Katni-483 442 (MP) 

15. Dr. Virendra Singh 

SMS/Asstt Prof. (Plant Protection) 


SVPUAT Cotton Research Farm 

D.M. Road, Bulandshahar (UP) 

16. Dr. Ram Suman Mishra 


Department of Vegetable Science 

N.D.U.A&T., Kumarganj 

Faizabad- 224 229 (UP) 

17. Dr. Phool Chand 

Jr. Scientist-cum-Assistant Professor 

Department of Plant Pathology 

Tirhut College of Agriculture 

(Rajendra Agricultural University) 

Dholi, Muzaffarpur- 843 121 (Bihar) 

18. Dr. Amar Singh 

Assistant Scientist (Plant Pathology) 

CSKHP Krishi Vishvavidyalaya 

Palampur- 176 062 (HP) 

19. Dr. Chandrashekara C. 

Scientist (Plant Pathology) 

VPKAS, (ICAR), Almora-263 601 (UK) 

(Mb.): 09865804560 

E-mail: rucklingraja@rediffmail.com 

(O): 04147-250001 

(Mb.): 09786730806 

E-mail: veltnau@rediffmail.com 

(O): 0368-2224887 

(Mb.): 09402477033 

E-mail: rcshakywar@gmail.com 

(O): 0721-2663076 

(Mb.): 09422766437 

E-mail: yog_ingle@rediffmail.com 

(O): 07622-268515 

(R): 07622-268515 

(Mb.): 09977244254 

E-mail: srsharma_srsgkp@rediffmail.com 

(Mb.): 09456841516 

9411477003 

E-mail: virendrdr@gmail.com 

(Mb.): 09450045737 

E-mail: drramsumanmishra@gmail.com 

(O): 0621-2293227 

(Mb.): 9661450698 

E-mail: phoolchand1964@gmail.com 

(O): 01894-230326 

(Mb.): 9418149782 

E-mail: singhamar008@gmail.com 

(O): 05962-230060 

(Mb.): 9557935569 

E-mail: chandrupath@gmail.com 

-ii-

20. Dr. Rajesh Kumar 


Department of Horticulture 

G.B.P.U.A.&T., Pantnagar- 263 145 (UK) 

21. Dr. Shilpi Rawat 

SMS (Plant Protection) 

Officer In-charge, KVK 

VCSG College of Horticulture 

UUHF, Bharsar-234 123 (UK) 

22. Dr. Mukesh Kumar Karnwal 

Asstt. Seed Scientist/JRO 

Deptt. of Genetics and Plant Breeding 


23. Dr. Shailesh Tripathi 


Department of Horticulture 


24. Dr. Ashwani Tapwal 

Scientist-D, Forest Pathology Division 

Forest Research Institute (FRI) 

Dehradun- 248 006 (UK) 

25. Dr. L.B. Yadav 


Department of Plant Pathology 


(O): 05944-233145 

(Mb.): 9415574127 

E-mail: rkshukla2006@gmail.com 

(O): 01348-226076 

(Mb.): 8216360611 

E-mail: rawat_shilpi2004@yahoo.com 

(Mb.): 9410188039 

E-mail: karan.mk23@gmail.com 

(O): 05944-233114 

(R): 05944-234108 

(Mb.): 9412970450 

E-mail: shaileshgbpuat@gmail.com 

(O): 0135-2224259 

(R): 09411141370 

(Mb.): 09411141370 

E-mail: ashwanitapwal@gmail.com 

tapwala@icfre.org 

(R): 05944-233211 

(Mb.): 9456345392 

E-mail: yadav_lalbahadur@yahoo.co.in 

S U M M A R Y 

Sl. No. State No. of participants 

1 Andhra Pradesh 01 

2 Arunachal Pradesh 01 

3 Bihar 01 

4 Gujarat 01 

5 Himachal Pradesh 01 

6 Jammu & Kashmir 02 

7 Karnataka 05 

8 Madhya Pradesh 01 

9 Maharashtra 01 

10 Tamil Nadu 02 

11 Uttar Pradesh 02 

12 Uttarakhand 07 

Total Participants 25 

-iii-

TRAINING 

ON 

ANNEXURE-III 

“MANAGING PLANT MICROBE INTERACTIONS FOR THE MANAGEMENT OF SOIL-BORNE 

PLANT PATHOGENS” 

(January 22 to February 11, 2013) 

Venue 

Sponsored by 

CAFT Hall, Plant Pathology 

Centre of Advance Faculty Training in Plant Pathology (ICAR, New Delhi) 

GUEST SPEAKERS/CONTRIBUTORS 

Dr. Serge Savary 

Dr. L. Willocquet 

Dr. U.S. Singh 

Dr. R.K. Khetarpal 

Dr. Rakesh Pandey 

Dr. Y.P. Singh 

Director of Research, Phytopathologist, INRA, France 

In-charge of Research, Phytopathologist, INRA, France 

Coordinator, South Asia, Bill & Melinda Gates Foundation 

(BMGF) Proj., International Rice Research Institute, New Delhi 

Science Director (Asia) and Country Director (India), CABI South 

Asia-India, 2nd Floor, CG Block, NASC Complex, DP Shastri 

Marg, Opp. Todapur Village,PUSA, New Delhi 

Scientist, Central Institute of Medicinal &Aromatic Plants, 

CIMAP), Near Kukrail Picnic Spot, Lucknow- 226 015 (UP) 

Principal Scientist, Forest Pathology Division, Forest Research 

Institute, Dehradun 

LOCAL SPEAKERS 

Dr. J. Kumar 


Dr. H.S. Tripathi 

Dr. R.P. Awasthi 


Dr. Pradeep Kumar 

Dr. K.P. Singh 


Dr. Y. Singh 


Dr. K.P.S. Kushwaha 


Dean, College of Agriculture 

Professor and Head-cum-Director CAFT Plant Pathology 

Ex-Professor, Plant Pathology 

Professor, Plant Pathology 




Assoc. Prof., Plant Pathology 

SRO, Plant Pathology 




-i-

Dr. Roopali Sharma 

Dr. Geeta Sharma 

Dr. S.K. Mishra 

Dr. Ramesh Chandra 

Dr. K.P. Raverkar 

Dr. Navneet Pareek 

Dr. P.C. Srivastava 

Dr. M.A. Khan 

Dr. S.N. Tewari 

Dr. R.P. Srivastava 

Dr. D.K. Singh 

Dr. H.S. Chawla 

Dr. P.K. Shrotria 

Dr. H.S. Kushwaha 

Dr. A.S. Nain 

Dr. Reeta Goel 

Dr. Anita Sharma 

Dr. Laxmi Tewari 

Dr. Anil Kumar Gupta 

Dr. Anil Sharma 

Dr. Balwinder Singh 

Dr. R.N. Pateriya 

JRO, Plant Pathology 



Profesor & Head, Soil Science 

Associate Professor, Soil Science 

Associate Professor, Soil Science 

Professor, Soil Science 

Professor, Entomology 



Associate Professor, Agronomy 

Prof. & Head, Genetics and Plant Breeding 

Professor, Genetics and Plant Breeding 

Professor, Agrometerology 

Assoc. Prof., Agrometerology 

Prof. & Head, Microbiology 

Assoc. Prof., Microbiology 

Assoc. Prof., Microbiology 

Prof. & Head, MBGE 

Assoc. Prof., Biological Sciences 

Assoc. Prof., Anatomy 

Assoc. Professor, Farm Machinery 

-ii-

ANNEXURE-IV 

CENTRE OF ADVANCED FACULTY TRAINING IN PLANT PATHOLOGY 

G.B. Pant University of Agric. & Tech., Pantnagar-263 145 (UK) 

Course Schedule (January 22 to February 11, 2013) 

“MANAGING PLANT MICROBE INTERACTIONS FOR THE MANAGEMENT OF SOIL-BORNE 

Venue 

PLANT PATHOGENS” 

: CAFT Hall, Department of Plant Pathology 

Day & Date Time Topic of Lecture Name & Designation 

of Speaker 

Tuesday 

22.1.13 

09:00-09:30 hrs Registration 

Venue: CAFT Hall, Plant Pathology 

Registration 

Committee 

09:30-10:00 hrs Introduction with Plant Pathology Faculty 

Venue: CAFT Hall, Plant Pathology 

Faculty, Plant 

Pathology 

10:00-11:00 hrs Inaugural Function 

Wednesday 

23.1.13 

Thursday 

24.1.13 

Friday 

25.1.13 

11:00-11:15 hrs Tea break 

Venue: Conference Hall, Agriculture College 

11:15-12:45 hrs Visit to laboratories of Department of Plant 

Pathology 

12:45-14:30 hrs Lunch 

Dr. Y. Singh 

14:30-17:00 hrs Visit to University Research Centers Drs. P. Kumar & 

Vishwanath 

09:30-10:30 hrs College of Agriculture at a Glance Dr. J. Kumar, Dean 

Ag. 

10:30-11:30 hrs IPM is the solution. But what is the problem? Dr. Serge Savary, 

France 


11:45-13:00 hrs A new on-line simulation course on plant disease 

epidemiology 

13:00-14:30 hrs Lunch 

14:30-15:30 hrs Department of Plant Pathology and CAFT 

activities at Pantnagar 


Dr. L. Willocquet, 

France 

Dr. K. Vishunawat, 

Director, CAFT 

15:45-17:00 hrs Interactive session with Participants & Students Dr. L. Willocquet, 

France 

09:30-10:30 hrs Soil degradation- a threat to sustainable Dr. Ramesh Chandra 

agriculture 

10:30-11:30 hrs Role of IPM in management of soil borne 

diseases 


Dr. Serge Savary, 

France 

11:45-13:00 hrs Discussion with participants Dr. Serge Savary, 

France 

13:00-14:30 hrs Lunch 

14:30-17:00 hrs Isolation, identification and quantification of 

Trichoderma (Practical) 

09:30-10:45 hrs Biodeterioration of seeds and its control by 

microbial antagonists 

10:45-11:00 hrs Tea Break 

11:00-12:30 hrs Role of organic amendments in the management 

of soil borne plant pathogens 




-i-

Saturday 

26.1.13 

Sunday 

27.1.13 

Monday 

28.1.13 

Tuesday 

29.1.13 

Wednesday 

30.1.13 

Thursday 

31.1.13 

Friday 

1.2.13 

12:30-14:30 hrs Lunch Break 

14:30-17:00 hrs TA settlement Drs. R.P. Awasthi & 

Vishwanath 

09:30-11:30 hrs Independence day programme at Gandhi Hall 

Visit to University library 

09:30-10:30 hrs Biological control of plant pathogens under 

sustainable agriculture: status and prospects 

10:30-11:30 hrs Influence of environmental parameters on 

Trichoderma strains with biocontrol potentials 


Dr. J. Kumar 

Dr. A. K.Tewari 

11:45-13:00 hrs Soil solarization for biocontrol of plant pathogens Dr. Yogendra Singh 

13:00-14:30 hrs Lunch 

14:30-17:00 hrs Visit to Biocontrol Lab & Mechanism of 

mycoparasitism and antibiosis (Practical) 


and Smita Puri 

09:30-10:30 hrs Suppressive soils in plant disease management Dr. K.P. Singh 

10:30-11:30 hrs Protected cultivation: Problems and Perspectives Dr. H.S. Tripathi 


11:45-13:00 hrs Visit to MRTC Drs. S.K. 

Mishra/Geeta Sharma 

13:00-14:30 hrs Lunch break 

14:30-17:00 hrs Visit to KNSCCF Dr. S.K. Mishra 

09:30-10:30 hrs Case studies: successes and problems 

encountered 

Dr. J. Kumar 

10:30-11:30 hrs Soil fertility in organic farming system Dr. D.K. Singh 


11:45-13:00 hrs Interactions of microbes in the phyllosphere and 

rhizosphere 


14:30-15:45 hrs Mass production and formulation technology of 

Trichoderma (Practical) 


16:00-17:00 hrs Identification of Pseudomonas and Bacillus 

isolates using Biolog system (Practical) 

09:30-10:30 hrs Role of entomopathogens in management of 

insect pests 

10:30-11:30 hrs Characterization of micro-meterological variables 

for disease management 


Dr. P.C. Srivastava 

Drs. A.K. Tewari 

/Roopali Sharma 

Drs. J. Kumar & 

Roopali Sharma 

Dr. S.N.Tewari 

Dr. H.S. Kushwaha 

11:45-13:00 hrs Role of soil micro-fauna in maintaining soil health Dr. Navneet Pareek 


14:30-15:30 hrs Induced resistance in plants for managing plant 

diseases 


15:45-17:00 hrs Isolation and identification of entomophagous 

fungi (Practical) 

Dr. P.K. Shrotria 

Dr. C.P. Singh 

09:30-10:30 hrs Biological management of seed borne pathogens Dr. K. Vishunavat 

10:30-11:30 hrs Microbes and intellectual property right (IPR) Dr H.S. Chawla 


-ii-

Saturday 

2.2.13 

Sunday 

3.2.13 

Monday 

4.2.13 

Tuesday 

5.2.13 

Wednesday 

6.2.13 

Thursday 

7.2.13 

11:45-13:00 hrs Biocontrol and integrated disease management in 

different environments 


14:30-15:30 hrs Role of plant growth promoting rhizobacteria in 

crop improvement 



Dr. Anita Sharma 

15:45-17:00 hrs Microbial degradation of pesticides Dr. Anita Sharma 

09:30-10:30 hrs Development of lower cost production storage and 

distribution systems of beneficial microbes 

10:30-11:30 hrs Biocontrol of fungal phytopathogens by 



11:45-13:00 hrs Evaluation and Selection of Promising 

Trichoderma Isolates For the Management of Soil 

Borne Fungal Plant Pathogens 


Dr. K.P. Singh 

Dr. Laxmi Tewari 


14:30-17:00 hrs Identification of Bacteria (Practical) Dr. Yogendra Singh 

10:00-11:00 hrs Integration of microbials and sustainable tools 

(compost, organic manures, biofumigation, crop 

rotation) for ecofriendly plant disease 

management 

11:00-11-15 hrs Tea break 

Dr. J. Kumar 

11:15-12:30 hrs Writing of Research Papers/Scientific reports Dr. J. Kumar 


14:30-17:00 hrs Visit to university library 

09:30-10:30 hrs Exploiting nematophagous fungi for the 

management of root knot nematodes 

10:30-11:30 hrs Role of microbes in management of forest 

diseases 


Dr. Rakesh Pandey, 

CIMAP 

Dr. Y.P.Singh, FRI, 

Dehradun 

11:45-13:00 hrs Management of root knot nematodes Dr. Rakesh Pandey, 

CIMAP 


14:30-15:30 hrs Implication of PGPR for Rhizosphere colonization 

and plant growth promotion 


Dr. Reeta Goel 

15:45-17:00 hrs Soil DNA extraction and its implication (Practical) Dr. Reeta Goel 

Visit to Research station, Majhera (Nainital) 

09:30-10:30 hrs Trichoderma as inducer of plant resistance to 

diseases 

10:30-11:30 hrs Reduced risk pesticides: safe and powerful tool 

for effective pest control 


11:45-13:00 hrs Disease resistance in plants through mychorrhizal 

fungi induced allelochemicals 


14:30-17:00 hrs Isolation and identification of mychorrhizal fungi 

(Practical) 

09:30-10:30 hrs Molecular mechanism associated with fungal 

pathogenesis and diseases resistance to Karnal 

bunt of wheat 

Drs. Pradeep Kumar & 

Vishwanath 


Dr. S.N. Tewari 



Dr Anil Kumar Gupta 

-iii-

Friday 

8.2.13 

Saturday 

9.2.13 

Sunday 

10.2.13 

Monday 

11.2.13 

10:30-11:30 hrs Remote sensing and GIS for stress management 

in plants 


11:45-13:00 hrs The role of biocontrol methods in integrated crop 

protection 

13:00-14:30 hrs Lunch 

Dr. A.S. Nain 

Dr. M.A. Khan 

14:30-15:30 hrs Microbes and soil quality Dr. K.P. Raverkar 


15:45-17:00 hrs Production technology of biofertilizers (Practical) Dr. K.P. Raverkar 

09:30-10:30 hrs Smut fungi: potential pathogen & biocontrol agent Dr. K. Vishunavat 

10:30-11:30 hrs Importance of bio-energy for sustainable 

agriculture 


11:45-13:00 hrs Identification of Trichoderma spp. using 

molecular tools (Practical) 


14:30-17:00 hrs Practical demonstration of scanning electron 

microscopy (Practical) 

Dr. R.N. Pateriya 

Dr. Anil Kumar Gupta 

Dr. Balwinder Singh 

09:30-10:30 hrs Pesticides: Past, Present and Future Dr. R.P. Srivastava 

10:30-11:30 hrs Presentation by participants 



12:30-13:00 hrs Evaluation of the training programme and 

feedback from trainees 


Dr. Yogendra Singh 

14:30-15:45 hrs Visit to Meterological observatory at N.E.B. CRC Dr. H.S. Kushwaha 


16:00-17:00 hrs Management of abiotic stresses in rice Dr. U.S. Singh, IRRI 

University Library visit 

09:30-10:30 hrs Bio-security and bio-safety issues in relation to 

plant pathogenic microbes 



Dr. R.K. Khetrapal 

11:45-13:00 hrs Quarantine for the management of plant diseases Dr. R.K. Khetrapal 


14:30-15:00 hrs Discussion with Plant Pathology Faculty 

15:00-16:00 hrs Valedictory Session 

-iv-

Managing Plant Microbe Interactions for the Management of Soil ...

You also want an ePaper? Increase the reach of your titles

Delete template?

Save as template?