Botryodiplodia sp. - Crops for the Future

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1 Summary Experiments were undertaken by the Industrial Technology Institute (ITI) in cooperation with the International Centre for Underutilised Crops (ICUC) to prove the availability of Trichoderma sp. in Sri Lanka and their effectiveness as Bio-control agents (BC-agents) against Botryodiplodia sp. The Trichoderma sp. used in the experiments were isolated from soil samples taken from several locations in Sri Lanka and the pathogens were isolated from diseased fruits of Annona squamosa, Annona muricata and rambutan (Nephelium lappaceum). Bio-assays were undertaken to prove the effectiveness of the BC-agents. In addition crossinoculation experiments were done to see whether the pathogens of various fruits infect each other. Furthermore a sporulation experiment was attempted to check if a reduction of the sporulation time of Botryodiplodia sp. under special treatments (cold shock and daylight) is possible. Following results of the experiments are shown: Isolates: Twelve isolates of Trichoderma were obtained from six different soil-sources and eight isolates of the pathogen from diseased fruits. One pathogen from each fruit was taken for further experiments. Bio-assay: The bio-assay experiment showed that three of the Trichoderma sp. isolates have a high, four have moderate and three have low Bio-control activity while three isolates observed to be non effective. Two of the Trichoderma strains with a high BC-activity were isolated from rambutan orchards in Warakapola and the third was found in a soil sample, taken from the surrounding area of an Annona muricata tree in Wijayapura. None of the isolates taken from Annona squamosa sources showed high BC-activity, while one was moderately effective against the pathogens. Cross-inoculation experiment: The pathogens which were cross-inoculated to the rambutan fruits showed an equal severity after the third day. On the first two days the severity that was caused by the pathogen isolated from Annona muricata was a little higher. 4
The cross-inoculation experiment with Annona muricata fruits did not lead to satisfactory results. The reason being that the severity of infection in the two controls were the same or higher to the severity caused by the pathogens. A statistically significant higher severity between pathogen taken from Annona muricata and the one taken from Annona squamosa compared to the others can be seen at the fifth day. The variability in the cross-inoculation experiment with Annona squamosa fruits was high; nevertheless we can conclude that the pathogens of the various fruits do infect the others. Sporulation experiment: The treatment with a cold shock resulted in the longest sporulation times of 26 days with respect to all pathogens which were observed; the pathogen isolated from a red skinned Annona squamosa which did not sporulate during the experimental period. The pathogens which were isolated from rambutan and Annona squamosa sporulated fastest (15 days) under the daylight treatment. The pathogens isolated from the red skinned Annona squamosa and from Annona muricata sporulated fastest (24 days) in the incubator without any treatment. The two collaborative Institutes are described in this report as well as the country. Characteristics of both fruits used for the experiments and other important Annona species (A. cherimola and A. reticulata) as well as the two fungi are also described. 2 Introduction The background for the research presented here was the “Berufspraktisches Projeksemester” (BPS) programme which has to be done as a practical part of the author’s studies towards a Bachelor of Science degree in Horticulture-Management. The work was done in two institutes in Sri Lanka: The International Centre for Underutilised Crops (ICUC) which has announced the internship and the Industrial Technology Institute (ITI) which was the main working place for the experimental trails. The Intern was involved in a project of ITI and conducted several experiments which are described on the following pages. The main task of the intern was to prove antagonistic effects of fungus (Trichoderma sp.) against a fungal pathogen (Botryodiplodia sp.). 5
Page 1: Control of Post Harvest Disease (Bo
Page 4 and 5: List of Figures Figure 1: The Sri L
Page 8 and 9: 3 Sri Lanka The Democratic Socialis
Page 10 and 11: 3.2 Climate The climate of Sri Lank
Page 12 and 13: valuable consultations in industria
Page 14 and 15: Rambutan trees are either dioecious
Page 16 and 17: However, the most important genus i
Page 18 and 19: 6.2.1.2 Annona muricata Annona muri
Page 20 and 21: Figure 9: Annona squamosa Figure 10
Page 22 and 23: Characteristically for this fungus
Page 24 and 25: Figure 15: Phialides of Trichoderma
Page 26 and 27: autoclave is used for liquid steril
Page 28 and 29: Figure 21: Soil sampling in a rambu
Page 30 and 31: 9.1.4 Isolation of the pathogen Mat
Page 32 and 33: The effectivity of the BC-agent was
Page 34 and 35: Figure 29: Experimental series of a
Page 36 and 37: Two of the Trichoderma sp. with a h
Page 38 and 39: Results of the sporulation experime
Page 40 and 41: 12 References ALAM, M.S., BEGUM, M.
Page 42 and 43: ONG, P.K.C., ACREE, T.E. and LAVIN,
Page 44 and 45: Figure 36: List of bio-control agen
Page 46: Tmu III Galagedera • Mycelial gro

Botryodiplodia sp. - Crops for the Future

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