HERBOLOGIA - anubih

U DK 63/66 ISSN 1840-0809
HERBOLOGIA
An International Journal on Weed Research and Control
Vol. 13, No. 2, December 2012

Issued by: The Academy of Sciences and Arts of Bosnia and Herzegovina
and the Weed Science Society of Bosnia and Herzegovina
Editorial Board
Paolo Barberi (Italy)
Shamsher S. Narwal (India)
Vladimir Borona (Ukraine) Zvonimir Ostojić (Croatia)
Daniela Chodova (Czech Republic) Lidija Stefanović (Serbia)
Mirha Đikić (B&H)
Taib Šarić (B&H)
Gabriella Kazinczi (Hungary) Stefan Tyr (Slovakia)
Senka Milanova (Bulgaria)
Editorial Council
Dubravka Šoljan (B&H), Chairman Mira Knežević (Croatia)
Katerina Hamouzova (Czech Republic) Gyula Pinke (Hungary)
Rabiaa Haouala (Tunisia)
Milena Simić (Serbia)
Zoran Jovović (Montenegro)
Andrej Simončič (Slovenia)
Gerhard Karrer (Austria)
Asif T anveer (Pakistan)
Editor-in-Chief: Academician Taib Šarić
Deputy Editor: Mirha Đikić
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CONTENTS
Page
1. M. Ravlić, R. Baličević, M. Knežević, I. Ravlić: Allelopathic effect of
scentless mayweed and field poppy on seed germination of winter wheat and
winter barley................................................................................................................. 1
2. A. Tanveer, M. Mansoor Javaid, A. Khaliq, R. N. Abbas, A, Aziz: Allelopathic
effect of Echinochloa crus-galli on field crops............................................................... 9
3. R. Khan, M. Haroon, M. Waqas, I. Ullah: Influence of plants water extracts
on the germination and early seedling growth of winter wheat................................ 19
4. M. Knežević, R. Baličević, M. Ravlić, J. Ravlić: Impact of tillage systems and
herbicides on weeds and soybean yield......................................................................... 29
5. Lj. Nikolić, D. Latković, J. Berenji, V. Sikora: Weed flora under organic maize
production conditions......................................................................................................41
6. Z. Jovović, N. Latinović, A. Velimirović, T. Popović, D. Stešević, D. Poštić:
Effect of chemical weed treatment on weediness and potato yield....................... 51
7. A. Knežević, B. Ljevnaić-Mašić, D. Džigurski, B. Ćupina: Plant cover of natural
pasture located in the vicinity of the town of Bočar.................................................. 61
8. Z. Domer, Ph. Q. Nam, M. Szalai, Z. Keresztes: Weed composition and diversity
of organic and conventional maize fields in Jâszsâg region, in Hungary................. 75
Instruction to Authors in Herbologia.........................................................................87
Referees of the papers in the Herbologia Vol. 13, No. 2 88

Herbologia, Vol. 13, No. 2, 2012
ALLELOPATHIC EFFECT OF SCENTLESS MAYWEED AND FIELD
POPPY ON SEED GERMINATION AND INITIAL GROWTH OF
WINTER WHEAT AND WINTER BARLEY
Marija Ravlić*, Renata Baličević, Mira Knežević, Ivana Ravlić
Faculty of Agriculture, Josip Juraj Strossmayer University in Osijek, Kralja Petra Svačića ld,
31000 Osijek, Croatia *mravlic@pfos.hr
Abstract
The allelopathic effect of water extracts from fresh roots, stems and
leaves of scentless mayweed (Tripleurospermum inodorum (L.) C.H.
Schultz) and field poppy (Papaver rhoeas L.) on germination and initial
development of winter wheat and winter barley was studied under laboratory
conditions. Results showed that all water extracts significantly reduced
germination of wheat and barley. The highest reduction was observed with
leaf extract of T. inodorum and was 97.3% and 66.8% for wheat and barley,
respectively. Weed extracts showed depressive effect on root and shoot
length and fresh weight of test plants. Maximum reduction of root and shoot
length was recorded with T. inodorum leaf extract. Inhibitory effect was
dependent on donor and recipient species and weed plant part. On average, T.
inodorum extracts had higher inhibitory effect than P. rhoeas extract. When
comparing weed plant parts, leaves were the most allelopathic, followed by
stems and roots. Winter wheat showed greater sensitivity to weed extracts
than winter barley.
Keywords: allelopathy, field poppy, scentless mayweed, water extracts, winter wheat, winter
barley
Introduction
The growth of crops is accompanied by weeds, which besides
competing for light, nutrients, moisture and space with the crop, can also
affect crops growth through allelopathy. Allelopathy is defined as any direct
or indirect harmful or beneficial effect of one plant, fungus or microorganism
on the other ones through production of allelochemicals that escape into the
environment (Rice, 1984). Allelochemicals are present in all plant tissue:
root, stem, leaves, flowers and fruit and can be released in four ways:
volatilization, leaching, exudation and decomposition. Entry of
allelochemicals into environment by leaching and decay of litter is of the
greatest importance for the relationship of crops and weeds (Đikić, 2005).
The release of allelochemicals in soil inhibits seed germination, growth and

Ravlic et al.
establishment of agricultural crops and vegetation (Aldrich and Kramer,
1997; Rice, 1979).
Scentless mayweed (Tripleurospermum inodorum (L.) C.H. Schultz)
is a winter or summer annual or sometimes short lived perennial. It is a weed
of cultivated crops and one of the dominant weeds in winter wheat (Saric et
al., 2011; Peschken et al., 1989). Field poppy (Papaver rhoeas L.) is one of
the most important broad-leaved weeds in winter cereals, a competitive weed
that can decrease wheat yield up to 32% (Tora et al., 2008). Allelopathic
effect of scentless mayweed on germination energy and capacity of cereals
has been reported (Dzienia and Wrzesinska, 2003; Kwiecinska et al., 2011).
The objective of the study was to determine the allelopathic effect of
water extracts from fresh roots, stems and leaves of scentless mayweed (T.
inodorum) and field poppy (P. rhoeas) on germination and early growth of
winter wheat and winter barley.
Materials and methods
The experiment was conducted in 2012 in the Laboratory of
Phytopharmacy and Plant Systematics at the Faculty of Agriculture in Osijek.
Plants of scentless mayweed and field poppy were collected at the
phenological stage 6/65 (Hess et al., 1997) of the weeds from naturally
infested fields and separated in laboratory into root, stem and leaf. Water
extracts from fresh plant parts were prepared according to Majeed et al.
(2012). Each plant part was cut into 1 cm pieces, crushed in distilled water at
1:5 ratio (20 g of plant material in 100 ml of water) and kept for 48 hours at
room temperature. Water extracts were obtained by filtering through muslin
cloth and after that with filter paper and stored in refrigerator for 24 hours.
Winter wheat (cv. Lucija) and winter barley (cv. Barun) seeds were
used in the germination test. The seeds were surface-sterilized for 20 minutes
with 1% NaOCl (4% NaOCl commercial bleach), then rinsed three times
with distilled water (Siddiqui et al., 2009). Twenty five seeds of each crop
were placed in sterilized Petri dishes (100 mm in diameter) on the top of filter
paper. In each Petri dish 5 ml of extract was added, while distilled water was
used as control. Petri dishes were kept at room temperature (22 °C ± 2 °C) for
eight days, observed daily and additional extract/water was added to each as
needed. Each treatment had four replications. Experiment was repeated twice.
Germinated seeds were counted daily for eight days. Germination
percentage was calculated for each replication using the formula: G =
(Germinated seed/Total seed) x 100. Mean germination time (MGT) was
calculated according to the equation of Ellis and Roberts (1981): MGT = £
(Dn) / Y, n>where n is the number of seeds that emergen od day D, and D is
number of days counted from the beginnign of germination. The germination
2

Allelopathic effect of scentless mayweed and field poppy on seed germination.
index (GI) was calculated by using the formula GI = No. of germinated
seeds/Days of first count + ... + No. germinated seeds/Days of final count
(AOSA, 1983). After eight days seedling root length (cm), shoot length (cm)
and fresh weight (mg) were determined. The collected data were analysed
statistically with ANOVA and differences between treatment means were
compared using the LSD-test at probability level of 0.05.
Results and discussion
Water extracts from fresh plant parts of T. inodorum and P. rhoeas
significantly reduced germination of both wheat and barley (Table 1). The
highest inhibition rate was observed with T. inodorum leaf extract which
reduced germination of wheat and barley for 97.3% and 66.8%, respectively,
while P. rhoeas stem showed the lowest reduction of germination, 50.7% and
22.8%. Dzienia and Wrzesinska (2003) and Kwiecinska-Poppe et al. (2011)
reported inhibitory effect of above-ground mass of scentless mayweed on
germination energy and capacity of wheat, rye and triticale.
Table 1. Effect of extracts on germination (%) and mean germination time
(MGT) of wheat and barley
Treatments
Germination (%) MGT (days)
Wheat Barley Wheat Barley
Control 98.5 a 99.0 a 2.0 e 1.9 c
T. inodorum root 34.5 c 41.6 de 4.8 abc 4.2 b
T. inodorum stem 7.1 d 63.2 be 4.1 cd 5.8 a
T. inodorum leaf 2.6 d 32.9 e 5.5 a 5.4 a
P. rhoeas root 46.3 be 56.2 cd 4.2 bed 3.9 b
P. rhoeas stem 48.6 b 76.4 b 3.6 b 2.3 c
P. rhoeas leaf 35.9 be 34.8 e 5.3 ab 4.6 b
a,b,c - means followed by the same letter within the column are not significantly different at P

Ravlic et al.
significant in all treatments compared to control, except for barley when T.
inodorum root extract was applied. Maximum reduction was recorded for
wheat with T. inodorum leaf extract and was 93.0%. According to their
inhibition potential, extracts can be ranked in the following order: T.
inodorum leaf > T. inodorum stem > P. rhoeas stem > P. rhoeas leaf > P.
rhoeas root > T. inodorum root. Similarly, Kwiecinska et al. (2012) observed
root reduction of rye and triticale with higher concentrations of extracts from
fresh and dry biomass of scentless mayweed.
Table 2. Effects of extracts on root and shoot length (cm) of wheat and barley
Treatments
Root length (cm)________ Shoot length (cm)
Wheat_____ Barley________________ Wheat_____Barley
Control 10.49 a 9.93 a 6.48 a 8.34 a
T. inodorum root 5.12b 9.01 a 5.10b 7.62 ab
T. inodorum stem 1.12 d 1.67 d 1.90 e 1.34 c
T. inodorum leaf 0.73 d 2.08 d 0.43 f 0.25 c
P. rhoeas root 3.72 c 6.81 b 4.72 be 7.19 ab
P. rhoeas stem 1.48 d 3.65 c 3.68 cd 6.38 b
P. rhoeas leaf 3.44 c 6.72 b 3.38 d 5.88 b
a,b,c - means followed by the same letter within the column are not significantly different at P T.
inodorum stem > P. rhoeas leaf > P. rhoeas stem > P. rhoeas root > T.
inodorum root.
The mechanism of inhibition on the seedling growth caused by
allelochemicals can be result of reduced cell division and/or cell elongation
(Iman et al., 2006).
Significant differences have been observed between treatments in
influencing wheat and barley fresh weight (Table 3). As compared to the
4

Allelopathic effect of scentless mayweed and field poppy on seed germination.
control, only P. rhoeas root extract showed no significant reduction in wheat
fresh weight. Contrary, only stems and leaves of T. inodorum reduced barley
fresh weight for 75.2% and 90.2%.
Germination index of both test plants was significantly reduced in all
treatments with weed extracts (Table 3). Reduction of GI in wheat varied
from 68.8% to 99.4% and in barley from 35.6% to 89.2%.
Table 3. Effect of extracts on fresh weight (mg) and germination index (GI)
of wheat and barley
Treatments
Fresh weight (mg) Germination index
Wheat Barley Wheat Barley
Control 85.47 a 139.09 a 42.22 a 46.66 a
T. inodorum root 57.19 b 103.94 a 7.04 cd 9.58 cd
T. inodorum stem 39.46 b 34.51 be 1.81 e 8.09 de
T. inodorum leaf 8.21 c 13.65 c 0.26 e 5.05 e
P. rhoeas root 58.92 ab 119.69 a 10.25 be 14.92 c
P. rhoeas stem 45.72 b 101.10 ab 13.19b 30.04 b
P. rhoeas leaf 43.02 b 97.41 ab 6.12 d 7.77 de
a,b,c - means followed by the same letter within the column are not significantly different at P

Ravlic et al.
Conclusions
Water extracts from fresh root, stems and leaves of T. inodorum and
P. rhoeas inhibited germination of winter wheat and winter barley. Inhibitory
effect varied from 22.8% to 97.4%. Mean germination time for both test
species was significantly increased compared to the control.
Water extracts had depressive effect on wheat and barley seedling
growth and fresh mass. The greatest reduction of root and shoot length of
wheat and barley were recorded in treatment with T. inodorum leaf and stem
extract.
Inhibitory effect of extracts was dependent on donor and recipient
plants and plant parts.
References
ALDRICH, R.J., R.J. KREMER, 1997: Principles in Weed Management. 2nd Edition. Iowa
State University Press.
AOSA, 1983: Seed vigor hand testing book. Contribution No. 32. To the handbook of seed
testing. Association of Official Seed Analysis. Springfield, IL.
DZIENIA, S., E. WRZESINSKA, 2003: Effects of water extracts from selected weed species
on germination energy and growth of cereal seedlings. Pam. Pul., 134, 79-87.
BIK lt, M. 2005: Allelopathic effect of cogermination of aromatic and medicinal plants and
weed seeds. Herbologia, 6 (1), 15-24.
ELLIS, R.A., E.H. ROBERTS, 1981: The quantification of ageing and survival in orthodox
seeds. Seed Sci. Technol., 9, 373-409.
HESS, M., G. BARRALIS, H. BLEIHOLDER, H. BUHR, T. EGGERS, H. HACK, R.
STAUSS, 1997: Use of the extended BBCH scale - general for the description of
the growth stages of mono- and dicotykedonous species. Weed Research, 37, 433-
441.
IMAN, A., S. WAHAB, M. RASTAN, M. HALIM, 2006: Allelopathic effect of sweet com
and vegetable soybean extracts at two growth stages on germination and seedling
growth of com and soybean varieties. Journal of Agronomy, 5, 62-68.
KALINOVA, S., I. GOLUB INOVA, A. HRISTOSKOV, A. ILIEVA, 2012: Allelopathic
effect of aqueous extract from root system of johnsongrass on the seed germination
and initial development of soybean, pea and vetch. Herbologia, 13 (1), 1-10.
KWIECINSKA-POPPE, E., P. KRASKA, E. PALYS, 2011: The influence of water extracts
from Galium aparine L. and Matricaria maritime subsp. inodora (L.) Dostal on
germination of winter rye and triticale. Acta Sci. Pol., Agricultura, 10 (2), 75-85.
MAJEED, A., Z. CHAUNDRY, Z. MUHAMMAD, 2012: Allelopathic assessment of fresh
aqueous extracts of Chenopodium album L. for growth and yield of wheat (Triticum
aestivum L.). Pak. J. Bot,. 44,165-167.
MARINOV-SERAFIMOV, P. 2010: Determination of Allelopathic Effect of Some Invasive
Weed Species on Germination and Initial Development of Grain Legume Crops.
Pestic. Phytomed., 25,251-259.
PESCHKEN, D.P., A.G. THOMAS, G.G. BOWES, D.W. DOUGLAS, 1989: Scentless
Chamomile (Matricaria perforata) - A New Target Weed for Biological Control. In
“Proc. VII. Int. Symp. Biol. Contr. Weeds, 6-11 March 1988, Rome, Italy” (ed. E.S.
Delfosse), pp. 411-416.1st. Sper. Patol. Veg. (MAF), Rome.
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RAOOF, K.MA., M.B. SIDDIQUI, 2012: Allelopathic effect of aqueous extracts of
different parts of Tinospora cordifolia (Willd.) Miers on some weed plants. J. Agric.
Ext. Rural Dev., 4 (6), 115-119.
RICE, E.L. 1984: Allelopathy. 2nd edition. Academic Press, Orlando, Florida.
RICE, E.L. 1979: Allelopathy An Update. Botanical Review, 45, 15-109.
SARIC, T., Z. OSTOJIC, L. STEFANOVIC, S. MILANOVA, G. KAZINCZI, L. TYSER,
2011: The changes of the composition of weed flora in South-eastern and Central
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TANVEER, A., A. REHMAN, M.M. JAVAID, R.N. ABBAS, M. SIBTAIN, A.U.H.
AHMAD, M.S. IBIN-I-ZAMIR, K.M. CHAUDHARY, A. AZIZ, 2010:
Allelopathic potential of Euphorbia helioscopia L. against wheat (Triticum aestivum
L.), chickpea (Cicer arietinum L.) and lentil (Lens culinaris Medic.). Turk. J. Agric.
For., 34,75-81.
TORRA, J., J.L. GONZALEZ-ANDUJAR, J. RECASENS, 2008: Modelling the population
dynamics of Papaver rhoeas under various weed management systems in
Mediterranean climate. Weed Res., 48,136-146.
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8

Herbologia, Vol. 13, No. 2, 2012
ALLELOPATHIC EFFECT OF Echinochloa crus-galli ON FIELD CROPS
Asif Tanveer*, Muhammad Mansoor Javaid1, Abdul Khaliq, Rana
Nadeem Abbas and Ahsan Aziz1
Department of Agronomy, University of Agriculture, Faisalabad, 38040, Pakistan.
'Department of Agronomy, University College of Agriculture, University of
Sargodha, Sargodha, Pakistan. * Corresponding author E-mail:
drasiftanveeraaf@hotmail.com
Abstract
Root, stem, leaf and inflorescence extracts of Echinochloa crus-galli
plants were used to determine their inhibitory and stimulatory effects on seed
germination and seedling growth of sunflower, wheat, barley, rice and maize.
Leaf extract of E, crus-galli was the most detrimental for rice, maize and
sunflower whereas stem extract was the most for wheat and barley
germination. Leaf extract significantly delayed the test species germination
(except sunflower) and decreased the germination index compared to control.
The greatest inhibition of sunflower and wheat root length was noted with E.
crus-galli leaf extract. Maximum inhibition of wheat and maize shoot length
was caused by stem extract. Whereas root and leaf extracts caused more
reduction in shoot length of barley and rice, respectively. Root extract of E.
crus-galli stimulated root dry biomass accumulation of sunflower and wheat.
In rice root and shoot dry matter accumulation was reduced with root, stem
and inflorescence extracts. These results suggest that extracts from various
parts of E. crus-galli may be a source of allelochemicals.
Keywords: allelopathy, Echinochloa crus-galli, barley, maize, rice, sunflower, wheat.
Introduction
Weeds have stimulatory or inhibitory effects on the seed germination,
seedling growth and development of their own kind and on other species
grown in their immediate vicinity, by means of producing allelochemicals
(Shauket et al., 2003; Macias et al., 2004). Weeds differ not only in
allelochemicals production but also different parts of same species may
produce allelochemicals varying in properties and concentration; hence they
vary in their allelopathic effects (Tanveer et al., 2010).
When susceptible plants are exposed to allelochemicals, their
germination, growth and development may be affected. Many grasses exhibit
allelopathy against other species. Hamayum et al. (2005) observed more
inhibitory effect of aqueous extract of E. crus-galli shoot on germination of
maize compared with rhizome extracts.

Tanveer et al.
According to Batish et al. (2009) leaf debris of Ageratum conyzoides
L. deleteriously affected the early growth of rice by releasing water soluble
phenolic acid into the soil environment. Inhibitory effect of Cynodon
dactylon (L.) Pers. on seed germination and seedling growth of Phaseolus
vulgaris L. and Triticum aestivum L. has been reported by Sarika and Rao
(2006), Bhawana et al. (2009) and Sarika et al. (2010). Leaf extract of
Parthenium hysterophorus L. showed complete failure of seed germination at
8% in Triticum aestivum, at 10% in Oryza sativa, at 12% in Hordeum
vulgare and Avena sativa. However, the seed germination of Zea mays was
not completely inhibited (Pandey et al., 2011).
Echinochloa crus-galli is the most problematic weed of lowland rice
in Pakistan. An important hindrance in its management is that even expert
farmers can not differentiate it from rice due to morphological similarities
particularly at vegetative stage. As a result the weed grows luxuriantly in rice
throughout crop growth period and adversely affects the efficiency of crop.
Its heavy infestation also causes lodging of crop.
Rice-wheat, rice-barley, rice-maize (spring) and rice-sunflower
(spring) are among the major cropping systems practiced in rice growing
areas of Pakistan. Problems arising from growing the same crop and presence
of its associated weeds in succeeding years include poor establishment and
stunted growth of the subsequent crops that leads to investigations of possible
causes, including allelopathy (Kruse et al., 2000). Inhibitory effects on
germination and establishments of crops caused by residues of either crops or
weeds have lead to investigation of the release of toxic compounds from such
residues. For example, the allelopathic interference of both living plant and
of plant residues of the highly aggressive weed Elytrigia repens, quackgrass,
has been strongly indicated (Weston & Putnam, 1985). It is hypothesized that
poor performance of rice-based cropping systems in Pakistan may be due to
harmful effects of metabolites released by the decaying E. crus-galli plants.
Therefore, keeping in view the possible role of E. crus-galli in suboptimal
crop establishment, the present investigations were made to find allelopathic
effects of E. crus-galli on germination of wheat, barley, rice, maize and
sunflower.
Materials and methods
About 150 days old mature plants of E. crus-galli were uprooted from
rice field growing at student’s farm, Department of Agronomy, University of
Agriculture, Faisalabad, Pakistan. The inflorescences, shoots, leaves and
roots of E. crus-galli were separated and dried at room temperature for one
month. Aqueous extracts were made by soaking plant materials in water
(1:20, w/v) for 24 hours and filtered through 10 and 60 mesh sieve. Hundred
10

Allelopathic effect of Echinochloa crus-galli on field crops
seeds of wheat, barley, rice, and fifty seed of maize and sunflower were
uniformly placed on filter paper (whatman No. 10) in Petri-dishes of 9 cm
diameter and moistened with equal amount (4 ml) of the respective extract or
distilled water (control) and topped with a sheet of filter paper. There were
four replications. The dishes were incubated at 20°C for wheat and barley
and 30°C for maize, sunflower and rice. Equal amount of respective extracts
were added whenever needed during the experiment.
Standard procedures were followed to record data on germination
percentage and index (Association of official seed analysis, 1990), mean
germination time (MGT) (Ellis and Roberts, 1981), root and shoot length,
root and shoot dry weight per plant.
Data were analyzed statistically using Fishers Analysis of Variance
technique and treatment means were compared at 5% probability level. (Steel
et al., 1997).
Germination
Results and discussion
Root, stem, leaf and fruit extracts of E. crus-galli affected
significantly the germination percentages, mean germination time (MGT) and
germination index (GI) of wheat, rice, maize and barley seeds as compared to
distilled water (control) (Table 1). Rice and maize seed germination was
significantly lowest with leaf extract while stem extract showed most
inhibitory effect on germination of wheat and barley seeds. Leaf extract of E.
crus-galli significantly delayed the germination of all test crops except
sunflower where maximum MGT was recorded with root extract that was
statistically at par with stem and fruit extract. Leaf extract showed most
deleterious effects on all test crops by decreasing GI but leaf extract was
statistically at par with stem extract in decreasing the value of GI of wheat
(Table 1). Maximum GI of test species was recorded with distilled water.
Leaf and stem extracts of E. crus-galli were most detrimental to seed
germination of all test crops. This suggested that the allelopathic compounds
11

Tanveer et al.
Table 1. Germination and germination traits of sunflower, wheat, barley, rice and maize seeds as influenced by extracts
of different E. crus-galli parts.
Germination (%) MGT(Days) GI
Treatment
Wheat Barley Rice Maize
Wheat Barley Rice Maize
Sunflower
Sunflower
Sunflower
Wheat Barley Rice Maize
Control 45.0a 88.5ab 99.3a 92.3ab 45.8a 2.9c 2.8b 3.0b 2.7b 2.7ab 19.4a 40.0a 42.2bc 84.7ab 19.9ab
Root Extract 33.0b 88.8ab 98.3ab 93.3a 42.3ab 3.7a 3.4a 3.1b 2.8b 2.8ab 14.2bc 38.4ab 43.6ab 82.4ab 19.7ab
Stem Extract 33.5b 86.3b 95.3b 90.5ab 44.8ab 3.5ab 3.4a 3.3ab 2.8b 2.4b 14.1bc 36.3c 42.1bc 77.1b 20.9a
Leaf Extract 32.5b 90.8a 97.8ab 81.0b 41.0b 3.1bc 3.4a 3.7a 2.9a 3.0a 13.5c 36.4c 40.3c 60.9c 18.5b
Fruit Extract 40.0ab 91.8 a 98.8a 97.3a 42.8ab 3.4ab 3.4a 2.9b 2.7b 3.0a 17.8ab 37.2bc 44.9a 89.4a 19.7ab
LSD (P>0.5) 2.9 3.8 3.4 11.9 4.7 10.1 0.4 0.5 0.1 0.4 0.5 1.7 2.4 10.1 1.718
Means sharing the same letter in a column do not differ significantly at 5% probability level.
12

Allelopathic effect of Echinochloa crus-galli on field crops
responsible for producing adverse effects on seed germination are present in
leaf and stem. This also implies that these allelopathic compounds might be
present in excessive amount in E. crus-galli leaf and stem as compared to
root and fruit extracts. These results are in line with those of Rice (1974)
who reported that roots generally contain fewer and less potent inhibitors
than leaves. These results are further supported by Pandey et al. (2011) who
found that the production of a wide range of secondary products by different
plant parts are the characteristics of species and these products may be
inhibitory to seed germination. In addition previous investigations of many
researchers such as Turk et al. (2003) and Iqbal et al. (2004) showed that
weeds caused variable inhibitory effects to different crops.
Seedling growth
Aqueous extracts of E. crus-galli root, stem, leaf and fruit did not
significantly inhibit the emergence of sunflower, wheat and barley seeds
while their effect was significant on emergence of rice and maize seed (Fig.
1). Leaf extract caused significantly maximum reduction in emergence of
rice seedling while stem extract was most inhibitory to maize seedling. Leaf
extract caused maximum reduction in root length of sunflower and wheat as
compared to extract of other parts of E. crus-galli (Table 2). Extracts from
different parts of E. crus-galli caused reduction in root length of barley as
compared to control but they did not differ statistically from each other for
producing this effect. Stem extract was most inhibitory to shoot length of
wheat and maize, while root and leaf extract caused more reduction in shoot
length of barley and rice, respectively. Effect of root, stem, leaf and fruit
extracts of E. crus-galli was non-significant on root length of rice and
maize, and shoot length of sunflower (Table 2).
Root extract of E. crus-galli had stimulatory effect on root dry
weight of sunflower and wheat showing more root dry weight value
compared with the seedlings raised with extract of other parts of E. crusgalli
and control (Table 3). Extracts from various parts of E. crus-galli
(except leaf extract) also showed stimulatory effect on rice root dry weight
compared with distilled water (control). Aqueous extracts from various parts
of E. crus-galli did not produce any significant effect on root dry weight of
barley and maize. Extracts from different parts of E. crus-galli (except leaf
extract in rice) caused increase in dry weight of sunflower and rice shoot
compared with control. Shoot dry weight of wheat, barley and maize was
influenced significantly by different extracts of E. crus-galli (Table 3).
13

Tanveer et al.
120
□ Control □ Root Extract 0 Stem Extract H Leaf Extract B F n
100
80
£
g 60
0£
¡ 4 0
W
20
LSD (P>0.5) NS NS NS 17.29 29.16
Fig. 1. Effects o f aqueous extracts o f different parts o f E. crus-galli on emergence
percentage o f sunflower, wheat, barley, rice and maize.
Emergence of all test crops except rice and maize was not influenced
significantly by E. crus-galli extracts. This might be due to little or no effect
of this weed extracts on emergence. It is suspected that extracts/leachates in
the soil are subjected to degradation resulting less phytotoxic effect to
emergence of crop seedlings as Kobayashi (2004) pointed out that
phytotoxicity of allelochemicals is influenced by soil factors, which leads to
reduction in their activity than that obtained in non-soil condition. Similarly
E. crus-galli affected germination more in non-soil conditions.
Root/shoot length and dry weight of test crops showed a variable
response to the application of various extracts of E. crus-galli. Leaf and
stem extracts of E. crus-galli were more inhibitory than root and fruit
extracts. Reduction in root growth of test crops seedlings suggested that the
activity of root might have been hampered by allelochemicals. Similarly,
Chon et al. (2000) reported that the root growth of alfalfa was reduced when
germinated seeds are exposed to allelochemicals in dilute aqueous solutions.
Previous reports by various scientists also supported our results as Chon et
al. (2002) reported that higher concentrations of leaf extracts inhibit both
root elongation and hypocotyl growth due to inhibition or delay of seed
germination. Our findings also corroborates earlier reports that root growth
is
14

Allelopathic effect of Echinochloa crus-galli on field crops
Table 2. Root and shoot length of sunflower, wheat, barley, rice and maize
seedlings as influenced by aqueous extracts of different parts of E. crusgalli.
Root length (cm)
Shoot length (cm)
Treatment
Wheat Barley Rice Maize
Sunflower
Sunflower
Wheat Barley Rice Maize
Control 11.0a 10.2a 18.2a 3.1 9.7 10.8 9.5a 19.6ab 6.2ab 11.7ab
Root Extract 9. lab 9.5ab 12.4b 2.9 10.2 8.3 10.0a 16.6b 4.9b 14.2a
Stem Extract 8.6ab 7.6c 12.7b 2.9 6.7 7.8 7.1b 19.0ab 7.2a 7.3b
Leaf Extract 7.7b 7.0c 13.1b 2.2 9.4 8.1 7.4b 20.0ab 3.2c 9.5ab
Fruit Extract 8.2ab 8.2bc 14.3b 2.9 8.8 9.6 9.5a 22.16a 5.2b 9.9ab
LSD (P>0.5) 2.9 1.4 3.2 NS NS NS 2.1 5.3 1.7 6.9
Means sharing the same letter in a column do not differ significantly at 5%
probably level.
Table 3. Root and shoot dry weight of sunflower, wheat, barley, rice and
maize seedlings as influenced by aqueous extracts of different parts of E.
crus-galli._______________________________ ________________________
Root dry weight (mg)
Shoot dry weight (mg)
Treatment
Wheat Barley Rice Maize
Sunflower
Sunflower
Wheat Barley Rice Maize
Control 18.0b 6.0ab 26.7 1.6bc 35.5 34.8b 7.8 21.3 4.4ab 41.8
Root Extract 43.3a 7.3a 22.3 2.4a 38.2 37.2ab 8.2 22.5 4.3ab 45.3
Stem Extract 23.0b 5.4b 14.1 2. lab 20.5 39.8a 7.1 16.9 5.7a 25.5
Leaf Extract 20.8b 5.7b 28.7 1.1c 36.0 37.5ab 7.7 19.6 3.0b 30.5
Fruit Extract 14.3b 5.9ab 22.8 1.7abc 29.5 37.0ab 7.3 24.4 4.5a 32.5
LSD (P>0.5) 12.1 1.5 NS 0.8 NS 4.1 NS NS 1.5 NS
Means sharing the same letter in a column do not differ significantly at 5% probably level.
more sensitive to application of extracts than seed germination or hypocotyl
growth (Chon et al., 2000; Sarika et al., 2010). Similarly, our results are
15

Tanveer et al.
also supported by Turk et al. (2003) who revealed that the application of
plant extracts not only inhibited radical elongation but other morphological
abnormalities were also observed as many of the extracts caused twisted
radical growth.
Aqueous extracts were also inhibitory to the shoot growth; that could
be explained by the fact that biomolecules inhibited cell division and
elongation through restricting gibberellin or indole acetic acid induced
growth, retardation of photosynthesis and inhibition or stimulation of
respiration, among others (Rice, 1974). These results are also in agreement
with the results of Turk et al. (2003) and Batish et al. (2009) who reported
that the flower and leaf extracts caused the greatest reduction in hypocotyls
length when compared with extracts from other plant parts.
References
ASSOCIATION OF OFFICIAL SEED ANALYSIS, 1990: Rules for testing seeds. Journal
of Seed Technology 12, 1-112.
BHAWANA, J., SARIKA, N. PANDEY, P.B. RAO, 2009: Allelopathic effect of weed
species extracts on germination, growth and biochemical aspects in different
varieties of wheat (Triticum aestivum L.). Indian Journal o f Agricultural Research,
43, 79-87.
BATISH D.R., S. KAUR, H.P. SINGH, K. KOHLI R, 2009: Nature of interference
potential of leaf debris of Ageratum conyzoides. Plant Growth Regulation, 57,
137-144.
CHON, S.U., S.K. CHOI, S.H.G. JUNG, B.S. PYO, S.M. KIM, 2002: Effect of alfalfa leaf
extracts and phenolic allelochemicals on early seedling growth and root
morphology of alfalfa and barnyard grass. Crop Protection, 21,1077-1082.
CHON, S.U., J.H. COUTTS, C.S. NELSON, 2000: Effect of light, growth media and
seedling orientation on bioassays of alfalfa auto toxicity. Agronomy Journal, 92,
715-720.
ELLIS, R.A., E.H. ROBERTS, 1981: The quantification of agent and survival in orthodox
seeds. Seed Science and Technology, 9, 373-409.
HAMAYUM, M., F. HUSSAIN, S. AFZAL, N. AHMAD, 2005: Allelopathic effect of
Cyperus rotundus and Echinochloa crus-galli on seed germination and plumule
and radicale growth in maize (Zea mays L.). Pakistan Journal o f Weed Science
and Research, 11, 81-84.
IQBAL, Z., A. FURUBAYASHI, Y. FJUJIL, 2004: Allelopathic effect of leaf debris, leaf
aqueous extract and rhizosphere soil of Ophiopogen japonicus ker-Gawler on
growth of plant. Weed Biology and Management, 4,43-48.
KOBAYASHI, K., 2004: Factor affecting phytotoxic activity of allelochemicals in soil.
Weed Biology and Management, 4,1-7.
MACiAS F.A., J.C.G. GALINDO, J.M.G. MOLINILLO, H.G. CUTLER, 2004:
Allelopathy: Chemistry and mode of action of allelochemicals: CRC Press.
PANDEY, H.P., A.K. RAZA, S.K. CHAUHAN, 2011: Assessment of allelopathic
aggression of Parthenium hysterophorus L. on seed germination and seedling
growth of some important cereals. Trends in Biosciences, Indianjoumals.com. 4.
RICE, E.L., 1974: Allelopathy. Academic Press: New York. USA.
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STEEL, R.G.D., J.H. TORRIE, D. DICKY, 1997: Principles and Procedures of Statistics. A
Biometrical Approach. 3rd Ed. McGraw Hill Book Co., New York, USA.
SARDCA, P.B. RAO. 2006: Effect of weed extracts on germination, seedling growth and
protein in french bean (Phaseolus vulgaris L.) varieties. Allelopathy Journal, 17,
223-234.
SARIKA, N. PANDEY, P.B. RAO, 2010: Allelopathic effects of weed species extracts on
some physiological parameters of wheat varieties. Indian J. Plant Physiology, 15,
310-318.
SHAUKAT S.S., Z. TAJUDDIN, I.A. SIDDIQUI, 2003: Allelopathic Potential of Launaea
procumbens (Roxb.) Rammaya and Rajgopal: A Tropical Weed. Pakistan Journal
of Biological Sciences 6: 225-230.
TANVEER A, A. REHMAN, M.M. JAVAID, R.N. ABBAS, M. SIBTAIN, A. AHMAD
M.S. IBIN-I-ZAMIR, K.M. CHAUDHARY, A. AHSAN, 2010. Allelopathic
potential of Euphorbia helioscopia L. against wheat (Triticum aestivum L.),
chickpea (Cicer arietinum L.) and lentil (Lens culinaris Medic./ Turkish Journal
of Agriculture and Forestry 34: 75-81.
TURK, M.A., M.K. SHATNAWI & M.A. TOWAHA, 2003: Inhibitory effect of aqueous
extract of black mustard on germination and growth of alfalfa. Weed Biology and
Management, 3, 37-40.
WESTON, L. A., A.R. PUTNAM, 1985. Inhibition of growth, nodulation, and nitrogen
fixation of legumes by quackgrass. Crop Science 25: 561-565.
17

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18

Herbologia, Vol. 13, No. 2, 2012
INFLUENCE OF PLANTS WATER EXTRACTS ON THE
GERMINATION AND EARLY SEEDLING GROWTH OF WINTER
WHEAT
Rahamdad Khan1*, Muhammad Haroon1, Muhammad Waqas1 and
Ikram Ullah2
1 Department of Weed Science, The University of Agriculture, Peshawar, Pakistan.
2 Department of Agronomy, The University of Agriculture, Peshawar, Pakistan.
‘Correspondence: weedscientist@aup.edu.pk
Abstract
A laboratory based trial using water extract was conducted to
investigate the allelopathic potential of Sorghum bicolor, Oryza sativa,
Helianthus annuus, Parthenium hysterophorus, Sorghum halepense and
Phragmites australis on wheat (Triticum aestivum L.) during December,
2010 in the Weed Science Research Laboratory, Department of Weed
Science, The University of Agriculture Peshawar, Pakistan. Fresh plants of
S. bicolor, O. sativa, H. annuus, P. hysterophorus, S. halepense and P.
australis were collected, dried and ground. Then the powder was soaked in
tap water @ 120 g L'1. Ten seeds of wheat were placed in Petri dishes
separately and different concentrations of extracts were applied according to
the requirements. A control treatment (0 g/liter) was also included for
comparison. The experiment was laid out in completely randomized design
(CRD) with three replications and treatments. The results showed that with
P. hysterophorus and H. annuus extract concentration significantly
decreased germination percentage, seed vigor index (SVI), shoot length
(cm) p lan t', shoot weight (g) plant'1of the test species. The tolerance order
of the wheat against the extract concentration of Oryza sativa L. and
Sorghum bicolor (L.) Moench. was higher than against the other species. In
the present study wheat proved more susceptible to P. hysterophorus and H.
annuus L extracts.
Keywords: allelopathy, wheat, germination percentage, seed vigor index.
Introduction
Wheat (Triticum aestivum L.) is one of the most significant annual
self-pollinated winter grain crop. Wheat was sown in Pakistan on an area of
9 million ha during 2008-2009 which produced 24 million tons grain yield
with an average grain yield of 2657 kg ha'1, while in Khyber Pakhtunkhwa
Province (KPK), it was grown on 769.5 thousand ha area which produced

Khan et al.
1204.5 thousand tons grain yield with an average grain yield of 1565 kg ha'1
(MINFAL, 2008-2009). Weed infestation is the main cause of low yields in
wheat in Pakistan and probably reduces yields by 25-30% (Nayyar et al.,
1994). Weeds compete with crop plants for different factors (Anderson,
1983) and sometime interfere with crop growth by releasing toxic
substances in the rhizosphere (Rice, 1984). Apart from direct effects, weeds
may also serve as alternate host for insect pests. According to Baloch (1993)
grain yield in Pakistan may be increased by up to 37% if weeds are properly
controlled.
Traditional methods for controlling weeds are time consuming,
weather dependent and labor intensive. Unwise use of herbicides in tropical
agriculture can create environmental hazards and their safety is also
uncertain (Kasasian, 1971). Allelopathy is a mechanism in which chemicals
produced by weed plants may increase or decrease the associated plant
growth. Rice (1984), defined allelopathy as the effects of one plant
(including microorganisms) on another plant via the release of chemicals
into the environments. Allelopathy refers to inhibitory or stimulatory effects
of one plant on other plants through release of allelochemicals in the
environment (Chandra Babu and Kandasamy, 1997). The plant produces
allelochemicals which interfere with other plants and affect seed
germination and seedling growth (Alam and Islam, 2002). Sorghum
{Sorghum bicolor) is well recognised for its allelopathic effects on other
crops (Putnam and DeFrank, 1983). Phenolic acids have been identified in
allelopathic rice germplasm (Rimando et al., 2001). Sunflower leaf extracts
caused reduction in radical and hypocotyl length of mustard seedling
(Wardle et al., 1991; Bogatek et al., 2006). Seed germination and seedling
growth inhibition of many crops have been reported by parthenium extracts
e.g. barley (Hordeum vulgare L.) and maize (Rashid et al., 2008). Seyed
(2007) reported that wild sorghum extract influenced the germination and
growth of com, though it can have an affect the germination indicator.
Allelopathy may also play an eminent role in the intraspecific and
interspecific competition and may determine the type of interspecific
association. The plant may exhibit inhibitory or rarely stimulatory effects on
germination and growth of other plants in the immediate vicinity (Nasira
and Moinuddin, 2009).
The purpose of this study was to determine the possible allelopathic
effects of different plant species in the agricultural fields of the country
{Sorghum bicolor, Oryza sativa, Helianthus annuus, Parthenium
hysterophorus, Sorghum halepense and Phragmites australis) on
germination and growth of wheat crop.
20

Influence of plant eater extracts on the germination and early seedling growth .
Materials and methods
The experiments was conducted during December, 2010 in the Weed
Science Laboratory The University of Agriculture Peshawar, Pakistan to
study the allelopathic effects of Sorghum bicolor, Oryza sativa, Helianthus
annuus, Parthenium hysterophorus, Sorghum halepense and Phragmites
australis on germination and growth of wheat crop. Mature plants were
harvested from New developmental Research Farm, The University of
Agriculture Peshawar, Pakistan. The samples were put in paper bags and
oven (WiseVen) dried at 65°C for 72 hours. All the plant samples were
grinded with a grinder and kept in paper bags under room temperature. After
grinding an aqueous extract solutions were made from each sample with a
ratio of 4:60 (4 gram sample and 60 ml distilled water) and left for 24h at
room temperature, and then filtered through two layers of muslin cloth to
obtain their aqueous extracts. The experiment was laid out using a
Completely Randomized Design (CRD) and each treatment replicated three
times. Twenty one plastic made Petri dishes (9 cm diameter in size) were
randomly arranged inside the Weed Science Laboratory and lined with three
layers of tissue paper. Seeds of wheat were thoroughly cleaned manually
and 10 seeds were carefully placed into each Petri dish using a forceps.
After noticing seed germination, the lids were carefully removed as to
record seed germination as well as allow the seedlings to grow up. The
experiment was looked after regularly for its entire duration of 12 days.
Seeds inside all Petri dishes were considered germinated whose radicals
appeared and counted visually. This activity was undertaken for two weeks
time until all the seeds were either germinated and/or expired. The shoots
length of all the seedlings was measured using a plastic measurement rod
while their fresh weight was measured using an electrical balance at the 12th
day growth stage. Data recorded during the experiment was added and
means were taken. The data means were then accordingly subjected to
Analysis of Variance (ANOVA) individually using MSTATC statistical
analysis package and means were separated by least significance test (LSD)
(Steel and Torrie, 1980) to identify significant differences.
Germination (%)
Results and discussions
Statistical analysis of the data showed the impact of the aqueous
extract of different plant species on germination (%) of wheat (Table 1). The
table showed that highest germination (%) was recorded at the control
(98%) followed by Oriza sativa L. (87%) which are satistically at par with
21

Khan et al.
Sorghum bicolor (L.) Moench (82%), while the lowest was recorded for
Parthenium hysterophorus L. (63.3%). This result indicates that Parthenium
hysterophorus L. has more inhibitory effect on wheat germination. Hence,
the present findings suggested preventing Parthenium infestation around the
crop fields which could be affected by the allelochemicals released by
Parthenium. The studies of Oudhia (2001) and Scrivanti (2010) showed that
extracts of Parthenium are highly inhibitory on the seedling growth of
Andropogon gerardii, Lactuca sativa, maize, Paspalum guenoarum and
Eragrostis curvula. The results are similar to Maharjan et al. (2007) who
have also found leaf extract of Parthenium the most inhibitory to the seed
germination of wheat and other crops. The results are similar to Khan et al.
(201 la) according to which parthenium greatly inhibits the germination (%)
of wheat. Aqueous extract of Parthenium hysterophorus L. extracts
significantly inhibited the Eragrostis tef seed germination due to released of
phytotoxins from Parthenium leaves (Tefera, 2002; Stephen & Sowerby,
1996). Khaliq et al. (2009) reported sunflower water extract has more
inhibitory effects as compared to water extract of Sorghum on the
germination of Cichorium intybus.
Table 1. Impact of the aqueous extract of different plant species on
germination (%) of wheat.
Plant species Germination (%)
Sorghum bicolor (L.) Moench.
Oryza sativa L.
Helianthus annuus L.
Parthenium hysterophorus L.
Sorghum halepense (L.) Pers.
Phragmites australis (Cav) Trin.
Control
82.00 bc
87.33 ab
78.00 bc
63.33 d
80.66 bc
72.00 cd
98.66 a
LSD (0.05) 11.939
Seed vigor index (SVI)
The analysis of variance of the data revealed that plant species
extract had significant effect on the means of the tested wheat (Table 2).
The means of the species demonstrated that the maximum SVI values
22

Influence of plant water extracts on the germination and early seedling growth..
(1331.1) were recorded for the control followed by Oriza sativa L. (902.04)
which are satistically at par with Sorghum bicolor (L.) Moench. (889.69)
and Phragmites australis (Cav) Trin. (835.29), while the lowest SVI
(439.11) was recorded for the Helianthus annuus L. (439.11). These
findings are in line with those of Mubeen et al. (2011) who found a
significantly minimum seedling vigor index (SVI) for rice seeds which were
soaked in the leaf extract of Trianthema portulacastrum. Yasin et al. (2012)
reported that application of extract of Calatropis procera significantly
reduced seedling vigor index (SVI) up to 130 %. Sajjan and Pawar (2005)
reported that Parthenium extract significantly decreased seed vigor index.
The results are greatly analogous to the results of Khan et al. (201 la).
Table 2. Impact of the aqueous extract of different plant species on seed
vigor index (SVI) of wheat seed.
Plant species
Sorghum bicolor (L.) Moench.
Oryza sativa L.
Helianthus annuus L.
Parthenium hysterophorus L.
Sorghum halepense (L.) Pers.
Phragmites australis (Cav) Trin.
Control
Seed vigor index (SVI)
889.69 b
902.04 b
439.11 d
476.73 cd
615.75 cd
835.29 b
1331.1 a
LSD (0.05) 164.45
Shoot length (cm) plant'1
Data in Table 2 revealed that aqueous extract of different plant
species had significant effect on shoot length of seedlings of wheat.
Concentration means showed that maximum shoot length (13.49 cm) was
found in control followed by Phragmites australis (Cav) Trin. (11.58 cm)
which are satistically at par with Sorghum bicolor (L.) Moench (10.84 cm)
and Oryza sativa L. (10.31 cm), while the lowest shoot length were recorded
by Helianthus annuus L. (5.67 cm) and Parthenium hysterophorus L. (7.54).
The leaf extract proved superior against seed inhibition of wheat. Present
findings suggest that the release of allelochemicals in low amounts
stimulates the growth, while the greater amounts results in inhibition of
23

Khan et al.
other plants. Similar results have also been reported by Khan et al. (201 lb).
Our results are also analogous to those presented by Khan et al. (2011c).
Results are similar to that of Tomaszewski & Thimann (1966) who found
that higher concentration of Parthenium greatly reduce the plant growth,
which might be due to inhibition of cell division as allelopathic chemicals
have been found to inhibit gibberellin and indoleacetic acid function. The
results are greatly analogous to Marwat et al. (2008) and similar with the
work of and Uygur and Iskenderoglu (1997) and Cheema et al. (2002) who
reported that different plant extract significantly decrease the shoot length of
horse purslane. Similar results were also reported by Saeed et al. (2011)
where smallest shoot length was recorded in Helianthus annuus L.
treatment. Sorghum water extract significantly reduced shoot length of T.
portulacastrum (Randhawa et al., 2002) and sunflower water extract
(Ashrafi et al., 2008) over control.
Table 3. Impact of the aqueous extract of different plant species on shoot
length (cm) of wheat.
Plant species
Sorghum bicolor (L.) Moench.
Oryza sativa L.
Helianthus annuus L.
Parthenium hysterophorus L.
Sorghum halepense (L.) Pers.
Phragmites australis (Cav)
Trin.
Control
Shoot length (cm)
10.84 b
10.31 b
5.67 d
7.54 c
7.64 c
11.58 b
13.49 a
LSD (0.05) 1.584
Shoot weight (g) plant"1
Data in Table 4 showed the significant effect of aqueous extract of
different plant species on the fresh shoot weight of wheat crop. The data
revealed that maximum shoot weight was recorded for control (157 g)
followed by Oryza sativa L. (111.67 g) and Phragmites australis (Cav)
24

Influence of plant water extracts on the germination and early seedling growth..
Trin. (93.33 g) while the lowest were recorded for Helianthus annuus L. (79
g) and Parthenium hysterophorus L. (82.00 g). The results are similar to
Mahaijan et al. (2007) who found significant allelopathic inhibition of
parthenium plant extracts on shoot growth of wheat and other crop species.
The results are similar to that of Ashrafi et al. (2008) which showed that
sunflower aqueous extract significantly reduced seedling weight of wild
barley.
Table 4. Impact of the aqueous extract of different plant species on fresh
__________________ shoot weight (mg) of wheat__________________
Plant species
Fresh shoot weight (mg)
Sorghum bicolor (L.) Moench.
Oryza sativa L.
Helianthus annuus L.
Parthenium hysterophorus L.
Sorghum halepense (L.) Pers.
Phragmites australis (Cav) Trin.
Control
86.66 c
111.67 b
79.00 cd
82.00 c
84.00 c
93.33 bc
157.0 a
LSD (0.05) 43.675
Conclusions
The conclusions made in light of the results obtained were that
Oriza sativa L. and Sorghum bicolor (L.) Moench have less toxic effect on
wheat seed germination. Hence it is recommended to use it as a bioherbicide
to control weeds in wheat crop. However, Parthenium hyterophorus L. and
Helianthus annuus L. have highly toxic compounds which resulted in the
germination failure or seedling growth retardation in wheat crop. Therefore,
pro-active preventative management of P. hyterophorus L. and H. annuus L.
is direly required in wheat crop. Further study also suggested checking its
allelopathic effect of these plant species on weed of wheat crop.
25

Khan et al.
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Khan et al.
28

Herbologia, Vol. 13, No. 2, 2012
IMPACT OF TILLAGE SYSTEMS AND HERBICIDES ON WEEDS
AND SOYBEAN YIELD
Mira Knežević1, Renata Baličević1, Marija Ravlić1, Jelena Ravlić2
'Faculty of Agriculture, J J. Strossmayer University in Osijek
Kralja Petra Svačića Id, 31000 Osijek, Croatia
2Koranska 18, 31000 Osijek, Croatia e-mail: Mira.Knezevic@pfos.hr
Abstract
Field experiments (2009-2010) were carried out in soybean on
lessive pseudogley soil in north-eastern Croatia to evaluate the impact of
three continuous tillage systems (conventional with mouldboard ploughing,
chisel ploughing, disk harrowing) and chemical weed control through split
application of post-emergence herbicides at reduced rates alone or in
combinations, on weed density, fresh weed biomass and crop yield. Total
weed density in untreated plots was significantly influenced by tillage and it
was the highest in disk-harrowing (202.0 plants m'2), medium in chisel
ploughing (126.5 plants m'2) and the lowest in mouldboard ploughing
(109.3 plants m'2). In comparison with conventional tillage, chisel
ploughing and disk harrowing increased weed number on average by 15%
and 85%, respectively, after only two years of experiment. The main weeds
were annual species of Echinochloa crus-galli (L.) PB., Ambrosia
artemisiifolia L., Chenopodium album L., and Polygonum lapathifolium L.
with a share of 89% and 83% of the total weed population and biomass,
respectively. The efficacy of herbicide treatments in the control of main
weeds did not vary significantly between tillage treatments. The best and
equal total weed biomass reduction of 96% was provided by both herbicide
combinations of imazamox 24 g + oxasulfuron 50 g plus thifensulfuronmethyl
6 g a. i. ha'1 and of oxasulfuron 60 g + oxasulfuron 60 g plus
thifensulfuron-methyl 4 g a. i. ha'1, whereas the treatment with imazamox
24 g + 24 g a. i. ha'1reduced the weed biomass by 93%. Weed control had
no impact on soybean yields that were significantly affected by year and
tillage. Compared to the highest yield with mouldboard ploughing (4183 kg
ha"1), the average percent yield decreases with chisel ploughing and disk
harrowing were 6% and 14%, respectively.
Keywords: soybean, tillage systems, imazamox, oxasulfuron, thifensulfuron-methyl, weed
density, weed biomass, crop yield

Knežević et al.
Introduction
In recent years, the soybean production has expanded in Croatia with
a growing area of about 56,000 hectares and with a tendency toward further
growth (FAOSTAT, 2010). Small family farms play an important role in
soybean production with a share of 45% of the total area under soybean in
Croatia (Vratarić & Sudarić, 2008). Tillage practices for soybean in northeastern
Croatia are mainly conventional, based on mouldboard ploughing at
30-35 cm depth in autumn then harrowing and seedbed preparation in the
spring.
As has been confirmed by numerous studies, conventional systems
based on deep tillage are becoming less rational because of economic and
environmental reasons. In recent years there has been a tendency in Croatia
towards less intensive systems of tillage such as reduced, minimum or non
tillage (Butorac et al., 1986; Žugec et al., 1995; Košutić et al., 2006; Jug et
al., 2006; Jukić et al., 2011). Several authors have reported that
conservation tillage systems lead to changes in the species composition and
abundance of weed species in cropping systems (Blackshaw et al., 1994;
Tuesca et al., 2001; Legere & Samson, 2004; Thomas et al., 2004) Weed
population shifts with reduced tillage were observed in an increase in annual
grasses, perennial weeds and wind-dispersed species (Torresen et al., 2003).
Because of that, one of the main concerns with the adaption of conservation
tillage practices are potential weed management problems. Weed control
programs developed under conventional tillage systems are seldom
appropriate for systems of conservation tillage using either reduced or notill
tillage. One of the essential prerequisites to the success of conservation
tillage is the development of an effective and economically successful weed
control program adapted to such tillage practices. Weed control efficacy of
herbicides in conservation tillage can also be affected by the presence of
residue mulch material (Banks & Robinson, 1982) and is dependent on the
mechanism of action of the herbicides. Previous studies of weed control in
soybean in Croatian conditions using conventional tillage system showed
consistent weed control with the application of a large number of pre- and
post- emergence herbicides with their correct choice in terms of weed
spectrum, weed growth stage and weed size (Skender et al., 1991; Barić et
al., 1998; Barić & Ostojić, 2000; Bilandžić et al., 2003; Knežević et al.,
2008, 2009). Long-term studies of weed population and their dynamics in
soybean provide a way to access the impact of conservation tillage systems
on weeds and apply appropriate weed management.
The objective of this study was to determine the impact of some
reduced tillage systems and current post-emergence herbicide combinations
in split application, particularly with lower than recommended rates, on
30

Impact of tillage sxstems and herbicides on weeds and soybean yield
weed density, fresh weed biomass and soybean yield in north-eastern
Croatia.
Materials and methods
The field trials on soybean (cv. Dora ) were carried out on lessive
pseudogley soil at Zdenci locality in north-eastern Croatia, in 2009 and
2010. The previous crop in both years was winter wheat. The experimental
design was randomised complete block with tillage as the main factor and
chemical weed control as the sub-factor with four replications. The main
plot size was 400 m2 (10 x 40 m). The subplot size was 20 m2 (2.25 x 9 m).
The three tillage treatments were: 1. CT - conventional tillage with
mouldboard plough at 30 - 35 cm depth and once disk harrowing in autumn;
2. CP - loosening with chisel plough at 15-20 cm depth; 3. DH - disk
harrowing two times at 8-10 cm depth. All tillage treatments included
harrowing and seedbed preparation in the spring. The pre-sowing
fertilisation was applied using 350 kg NPK (10:20:30). Soybean was sown
in the first and third decade of April in 2009 and 2010, respectively, with
the inter-row spacing of 45 cm, and at the depth of 4 to 6 cm. The two top
dressings of the crop were performed at the first trifoliate growth stage (100
kg/ha of KAN and before the beginning of the flowering (100 kg/ha of
KAN). No inter-row cultivation was performed on crop. Weather conditions
during the soybean growing season (April, September) are presented in
Table 1.
Table 1. Weather conditions during soybean growing seasons
April May June July August September Total/
Year/Month
Mean
2009 p* 25 94 84 28 37 43 311
rp* 14.6 18.3 19.7 23.0 22.9 19.3 19.6
2010 P 70 183 239 47 59 198 796
T 11.9 16.7 20.0 23.2 21.6 15.5 18.2
1997-
2008
P 66 69 98 77 85 101 496
T 11.7 17.2 20.7 22.0 21.4 16.1 18.2
P* precipitation (mm), T* - temperatures °C
Chemical weed control included the following post-emergence
herbicide treatments: 1. imazamox (Pulsar 40) 24 g + 24 g a. i. ha"1; 2.
imazamox 24 g + oxasulfiiron (Laguna) 50 g plus thifensulfuron-methyl
31

Knezevic et al.
(Harmony 75) 6 g a.i ha'1; 3. oxasulfuron 60 g + oxasulfuron 60 g plus
thifensulfuron-methyl 4 g a.i. ha'1. All herbicides were applied with an
addition 0.2 L ha'1 of the surfactant Trend 90 EC. The herbicides were
applied first time when the annual grass weeds were mainly at the 1 -2 leaf
stage, and broad-leaved weeds were at the 2-4 leaf stage, whereas soybean
crop was at the first to three trifoliate stages (V1-V3). Regarding herbicide
combinations, the second application was conducted about 7-14 days after
the initial application. Herbicides were applied at a water volume equivalent
to 200 L ha 1 by a flat-fan nozzle using a Solo knapsack sprayer at a
pressure of 300 kPa.
Weed samples were collected by counting plant numbers of each
weed species in a 0.25 m2, replicated 16 times per plot and fresh biomass of
weeds was immediately weighted. An actual weed infestation was performed
first time before the post-emergence chemical control, then 14 days after the
final herbicide application, and again one month after the initial application.
Weeds on untreated control plots were pulled out at the beginning of the
soybean flowering (Rl). Weed control was expressed as percentage of
reduction in fresh weed biomass compared to the untreated control. Soybean
was mechanically harvested and grain yield was recorded and adjusted to
13% of the moisture content.
The data on plant density and fresh biomass of certain weed groups,
as well as the crop yield, were subjected to an analysis of variance and
tested by F-test (Fisher’s Protected LSD test), using Microsoft Excel and
Statgraf programme. For the analysis of variance, the main factor was the
year, tillage treatments were used as the sub-factor and weed control
treatments as the sub-sub-factor.
Results and discussion
A total of 9 and 11 weed species were identified in the spring
assessment in 2009 and 2010, respectively. Annual broad-leaved species
dominated the weed flora in all tillage systems with 8 species compared to
two perennials and one grass species. The main weeds were Echinochloa
crus-galli (L.) PB., Ambrosia artemisiifolia L., Chenopodium album L. and
Polygonum lapathifolium L. These weeds were present in both seasons with
more than 5 plants per m and a share of 89% and 83% in the total weed
density and biomass, respectively. The density and biomass of certain weed
groups varied among year and tillage systems (Fig. 1,2).
32

Impact of tillage systems and herbicides on weeds and soybean yield
The 2010 growing season was favourable for weed germination due
to high precipitation (Table 1), so that in that year a greater weed density
and biomass occurred compared to the preceding year. In the wet season,
the main weeds of E. crus-galli (140 shoots m" ), A. artemisiifolia (51 plants
m ") and P. lapathifolium (11.7 plants m ") increased their populations by
122%, 112% and 41%, respectively. On the contrary, in 2010 C. album
developed a reduced population number of 7.3 plants m"2 compared to 9.1
plants m'2 in 2009, as has been previously reported by Knežević et al.
(2009).
In relation to tillage, the significantly highest total weed density was
found in DH tillage (202.0 plants m' ), whereas the lowest one was found in
CT tillage system (109.3 plants m'), on average. Weed density in CP tillage
/j
showed intermediate values between CT and DH systems (126.5 plants m' ).
In comparison with CT, reduced CP and DH tillage treatments increased
weed density on average by 15% and 85%, respectively, after only two
years of experiment. No significant differences in weed density and biomass
were observed between the CT and CP treatments. Tillage effects on density
and biomass of weed groups were significant only for the DH treatment.
These results concur with our earlier findings in maize and winter wheat
crops (Knežević et al., 2003a, 2003b, 2003c) and also with other studies
(Blackshaw et al., 1994; Mulugeta et al., 2001; Legere & Samson, 2004)
that reported greater weed densities under reduced tillage than under CT
tillage system. In our experiment, E. crus-galli density and biomass was
greater with disk harrowing than with chisel ploughing and the lowest
values were achieved under mouldboard ploughing. Perron & Legere (2000)
found that in soybean for Canadian conditions a greater E. crus-galli density
and biomass was obtained with chisel ploughing than with mouldboard
ploughing under mechanical weed control. Tripleurospermum inodorum
(L.) C.H. Schultz was an important species in both reduced CP and DH
tillage treatments with 4.0 and 9.2 plants m'2, respectively, while it was
absent in the CT tillage. The only perennial species present in our study
were Cirsium arvense (L.) Scop, and Convolvulus arvensis L. in relatively
low densities and biomass (Fig 1, 2).
The herbicide efficacy, measured as a relative reduction in weed
fresh biomass compared to the untreated plots, differed by year but not by
tillage systems. The overall efficiency of herbicides was greater in 2010
33

Knezevié et al
(96.7%) than in 2009 (94.6%), probably because of environmental
conditions. In the wet season of 2010 weed control efficacy was high
because a large number of weeds emerged early in the season. On the
contrary, in the unfavourable 2009, which was associated with hot, dry
conditions, the emerging of weeds was uneven and extended to late in May
and June after heavy precipitation. However, the weeds that emerged after
herbicide application were small in size and did not affect the crop yield.
All herbicide treatments provided good or excellent biomass
reduction of E. crus-galli by 96%, 94% and 93% in 2009 and 98%, 96% and
95% in 2010 in CT, CP and DH tillage systems, respectively. In addition,
herbicide treatments ensured a good biomass reduction of broad-leaved
weeds in all tillage treatments that ranged from 92% to 95% in 2009 and
from 96% to 97% in 2010. However, herbicides were ineffective against
perennial weeds (Fig. 3)
Means followed by the same letter within certain weed groups are not statistically different at P < 0.05.
Fig. 1. Weed density of certain weed groups on untreated soybean plots as affected
by tillage systems
34

Impact of tillage systems and herbicides on weeds and soybean yield
Means followed by the same letter within certain weed groups are not statistically different at P < 0.05.
Fig. 2. Weed biomass of certain weed groups on untreated soybean plots as
affected by tillage systems
In a two-year average, the herbicide combinations of imazamox +
oxasulfuron plus thifensulfuron-methyl (96.8%) and of oxasulfuron +
oxasulfuron plus thifensulfuron-methyl (96.6%) in split application at
reduced rates were more effective in biomass control of weeds than the
treatment with imazamox (93.4%).
The lowest but still satisfactory biomass control was achieved in
2009 in the same treatment with imazamox (1) against A. artemisiifolia and
C. album (88%), but without affecting the crop yield. When imazamox was
applied in combination with oxasulfuron plus thifensulfuron-methyl mixture
(2), it increased A. artemisiifolia and C. album control to 92% -97% and to
98% -100%, respectively. There have been several studies reporting postemergence
weed control by imazamox as one of the imidazolinone
herbicide used for broad-spectrum in soybean and other crops. Nelson &
35

Knežević et al.
Renner (1998) found good C. album biomass control of 88-90% with
imazamox at 45 g ha"1 in soybean. In addition, our previous studies have
indicated that imazamox provided 86-91% control of C. album at the
recommended rate of 40 g ha'1, applied single (Knežević et al., 2008).
Ballard & Hellmer (1995) improved A. artemisiifolia and C. album control
with imazamox at 45 compared to 35 g a. i. ha'1. The results of Šćepanović
et al. (2008) have shown that imazamox at 40 g ha"1reduced the C. album
biomass to 64%-90%, depending on location.
M ouldboard ploughing Chisel ploughing Disk harrowing
1. imazamox 24 + 24 g a.i. ha'1
2. imazamox 24 + oxasulfiiron 50 plus thifensulfuron-methyl 6 g a.i. ha'1
3. oxasulfuron 60 + oxasulfiiron 60 plus thifensulfuron-methyl 4 g a.i. ha'1
Fig. 3. Efficacy of post-emergence herbicide treatments on biomass
reduction of certain weed groups in the three tillage systems
Soybean yields were significantly influenced by the year and tillage
treatment (Table 2). Average yields were significantly higher in 2010 (4362
kg ha'1) than in 2009 (3455 kg ha'1). The unfavourable weather conditions in
2009 with a spring and the summer drought resulted in a reduction of crop
yields by 21% across tillage treatments, compared to 2010. The lowest yield
was found in DH tillage where the decrease in the yield was 14% compared
to the CT tillage (3662 kg ha'1). No significant differences were observed in
yields between CT and CP tillage treatments in the first year of experiment.
36

Impact of tillage systems and herbicides on weeds and soybean yield
In 2010, the highest yield was obtained in CT (4703 kg ha'1), the lower in
CP (4336 kg ha'1) and the lowest in DH (4047 kg ha'1) with significant
differences between three tillage treatments.
Table 2. Grain yield (kg ha'1) of soybean as affected by tillage and
herbicides during two growing seasons
Year
Herbicide
Tillage treatments
Mean for
treatments
Mouldboard
Chisel
Disk
herbicides
ploughing
ploughing
harrowing
2009 1 3475 a 3608 a 3150 a 3501 a
2 3573 a 3557 a 3223 a 3451 a
3 3669 a 3499 a 3074 a 3414 a
Mean 3662 a 3555a 3148 b
2010 1 4683 a 4304 a 4018 a 4335 a
2 4777 a 4495 a 3945 a 4406 a
3 4650 a 4207 a 4178 a 4345 a
Mean 4703 a 4336 b 4047 c
2009-
2010
1 4214 a 3956 a 3584 a 3918 a
2 4175 a 4026 a 3584 a 3928 a
3 4159 a 3853 a 3626 a 3880 a
Mean for tillage 4183 a 3945 b 3598 c
The means followed by the same letter are not significantly different
LSD (P

Knežević et al.
program in reduced tillage systems as in the conventional tillage without
increasing the herbicide use. However, since these conclusions apply only to
the early years of these reduced tillage systems, further research is needed to
test them in additional years and report a potential build-up of perennial
weeds, expected to occur over time.
Acknowledgements This work was supported by the Croatian Ministry of Science,
Education and Sports ("Integrated arable crop protection from weeds"- 079-0790570-2716).
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VRATARIĆ, M., A. SUDARIĆ, 2008: Soja (Glycine max (L.) Merr.) Poljoprivredni
institut Osijek, 460.
ŽUGEC, I., I. JURIĆ, M. JOSIPOVIĆ 1995: Neke mogućnosti reduciranja obrade tla u
uzgoju soje na području istočne Hrvatske. Poljoprivreda, 1,105-114.
39

Knežević et al.
40

Herbologia, Vol. 13, No. 2, 2012
WEED FLORA UNDER ORGANIC MAIZE PRODUCTION
CONDITIONS
Ljiljana Nikolic1, Dragana Latkovic1, Janos Berenji2, Vladimir Sikora2
'Faculty of Agriculture, University of Novi Sad, Serbia
institute of Field and Vegetable Crops, Novi Sad, Serbia
e.mail: linik@t>oli.uns.ac.rs. dragana@.poli.uns.ac.rs.
berenii@.eunet.rs. vladimir.sikora@nsseme.com
Abstract
The paper presents taxonomic and biological analysis of weeds
found in maize grown according to the organic farming principles during the
period 2011-2012 on the experimental field of the Institute of Field and
Vegetable Crops, Novi Sad, at the Backi Petrovac locality. The presence of
19 species of weed plants, grouped in 18 genera and 13 families, was
established. The weed flora was dominated by representatives from the
Magnoliopsida class (dicots, broadleaf weeds), with 18 identified species,
whereas Liliopsida class (monocots, narrow-leaved weeds) was represented
by a single species. Among the identified weeds, the most abundant were
Datura stramonium L., Chenopodium album L., Chenopodium hybridum L.,
Solanum nigrum L., Polygonum lapathifolium L., Amaranthus retroflexus L.
and Convolvulus arvensis L. According to the classification by habitat,
weed-ruderal plants predominate (73.7%), whereas in the biological
spectrum, terophytes were most abundant, with the same percentage
participation (73.7%). Most of the identified weeds are characterized by a
long flowering period, allowing them, in the absence of control measures, to
successfully complete the vegetative cycle and form seeds in the maize
crop. Understanding the weed biological characteristics is the main
prerequisite for successful implementation of integrated weed suppression
and control methods in organic crop production.
Keywords: weed flora, maize, organic production.
Introduction
In the recent years, there has been a marked increase in the attention
devoted to organic farming, which contributes to the conservation of
biological diversity (Diver, 2001; Barberi, 2002; Kristiansen, 2003;
Malesevic et al., 2010; Nikolic et al., 2011,). Within agroecosystems, weeds

Nikolic et al.
hold a prominent place, as this is a specific group of plants that, on the one
hand, contributes to their floristic diversity, but on the other hand, from an
agronomic perspective, is an undesirable crop companion, causing many
adverse effects that can affect the yield and product quality (Kojic and
Janjic, 1994, Zaragoza et al., 2012).
In conventional farming, weed suppression and control is typically
achieved through herbicide application. However, one of the basic
principles of organic agriculture is exclusion of herbicides in the effort to
combat weed proliferation, and attempting to establish an optimal
relationship between weeds and crops by other means. Thus, in recent years,
many efforts have been invested in studying the allelopathic interactions
between weeds and crops (Economou et al. 2006; Iqbal et al. 2003; Sang-
Uk Chon et al. 2005; Iman et al. 2006; Janjic et al., 2008; Marinov-
Serafimov, 2010), the results of which could find implementation in the
future organic agricultural production systems. However, in the actual
organic production systems, mechanical or manual removal of weeds from
crops is most commonly used, whereby timely action requires knowledge of
their biological characteristics.
It is necessary to ascertain and monitor the status of the weed flora in
the crops in order to anticipate the necessary measures that can reduce the
weed populations to tolerable levels. Within these studies, special attention
is paid to the understanding of the floristic composition and biological
characteristics, such as flowering/fruiting, species background and life form,
etc., which is an important prerequisite for the prediction and proposal of
weed proliferation control measures (Kovacevic, 2008; Kovacevic et al.,
2009; Ilic et al., 2009; Nikolic et al. 2009, 2012; Zaragoza et al., 2012).
The goal of this work is the taxonomic and biological analysis of
weeds in maize crops grown according to the organic agriculture principles.
Our results will expand the current understanding of the composition of the
weed flora and their biological properties as a main precondition for taking
appropriate and timely measures for weed suppression and control in order
to achieve levels that can be tolerated by maize crops. The aim is to obtain
safe food and ensure sustainable agricultural development, taking into
account the principles of environmental and biodiversity protection.
Material and methods
Our studies of weed flora in maize crops grown according to the
organic agriculture principles were undertaken during the 2011-2012 period,
at the experimental field of the Institute of Field and Vegetable Crops, Novi
Sad, Department of Organic agriculture and biodiversity in Backi Petrovac.
Weed identification and collection in the field was conducted in two stages -
42

Weed flora under organic maize production conditions
in Phase 3 to 4, and later in Phase 7 to 8 of fully developed maze leaf. In
the studied area, the following maze hybrids were cultivated according to
organic principles: ZP 555su - FAO of the ripening group 500, NS 611k,
NS 6030 and NS 609b FAO of the ripening group 600.
The experiment was conducted on chernozem soil type,
characterized by loess and loess-like sediments, which was calcareous
gleyed and of medium depth (Škorić et al., 1985).
Prior to planting maize, soya was grown on the study area and the
plots were subjected to mechanical means of weed control only. More
specifically, row cultivation and hand hoeing was performed on two
occasions. However, these agrotechnical practices were implemented after
floristic recording of weed vegetation.
Plant material was identified according to the previous work by
Josifović (1970-1986) and Tutin (1960-1980). Life forms were determined
in line with Ujvarosi (1973), categorization by habitat was based on Kojić et
al. (1972), and flowering time was established according to Čanak et al.
(1978) and Josifović (1970-1986). Grouping by higher taxonomic categories
was performed in line with Takhtajan (1997).
Results and discussion
Based on the taxonomic analysis of weed flora in maize crops
cultivated according to the organic farming principles, the presence of 19
species of vascular macrophytes grouped in 18 genera and 13 families was
ascertained. The results indicate that the weed flora of the study area is
dominated by representatives of the Magnoliopsida class (dicotile, broadleaf
weeds) with 18 species, while the Liliopsida class (monocotile, narrowleaved
weeds) was represented by only one species, Sorghum halepense (L.)
Pers. (Tab.l).
The identified weed flora is comprised of species characteristic for
maze crops grown in Vojvodina (Kojić et al., 1972), amongst which Datura
stramonium L., Chenopodium album L., Chenopodium hybridum L.,
Solanum nigrum L., followed by Polygonum lapathifolium L., Amaranthus
retroflexus L. and Convolvulus arvensis L., Eire the most abundant.
According to the established list of invasive plants for the Vojvodina
region (http://iasv.dbe.pmf.uns.ac.rs/index.php?strana=baza'). five weed
species (26.3%) - Amaranthus retroflexus L., Portulaca oleracea L., Datura
stramonium L., Sorghum halepense L. and Ambrosia artemisiifolia L. -
belong to the invasive plant category, the number and proliferation of which
must be monitored, due to their potential negative effect on the given
agroecosystem, as well as the biodiversity in general (Vrbničanin et al.,
2004; Stojanović et al., 2009). Lešnik (2012) states that, in Slovenia,
43

Nikolic et al.
significant number of invasive species grow amongst maize crops, owing to
their plasticity, reproductive strength, significant competence, as well as use
of herbicides. Based on the European list of invasive Magnoliophyta species
('www.europe-aliens.org'). we highlight that all the species «identified in the
studied maize crop are invasive for the European region. This should not be
overlooked when attempting to eradicate them and prevent their expansion
beyond these cultivated plots, as the problem of invasiveness is increasingly
apparent at the global level (Ziska et al., 2010).
Table 1. Taxonomic review of the weed with life forms,
categorization according to site and time of flowering
Life Category Time of
Class Family Genus Plant species for accordin floweri
m g t0 site ng
Fabaceae Lathyrus L. tuberosus L. Gi wr VI
Euphorbiace
ae
Euphorbia
E. cyparissias
L.
g 3 wr IV-VII
Brassicaceae Sinapis S. arvensis L. t 3 s V-IX
Malvaceae Hibiscus H. trionum L. t 4 s VI-VIII
Chenopodiac
eae
Chenopod
ium
C. album L. t 4 wr VI-XI
cS
3"m
P h
O
”3 GÜ0
Amaranthace
ae
Amaranth
us
C. hybridum L. t 4 wr V-VIII
A. retroflexus
L.
t 4 wr VI-IX
c3
S
Polygonacea
e
Bilderdyki
a
B. convolvulus
(L.) Dum.
t 4 wr VI-IX
Polygonu
m
P.
lapathifolium
t 4 wr VI-IX
Convolvulac Convolvul C. arvensis L. G3 wr VI-IX
44

Weed flora under organic maize production conditions
eae
Portulacacea
e
us
Portulaca P. oleracea L. t 4 wr VI-VIII
Solanaceae Datura D. stramonium t 4 wr VI-IX
Solanum S. nigrum L. t 4 wr VI-X
Lamiaceae Stachys S. annua L. t 4 s VI-X
Asteraceae Ambrosia A.artemisiifoli T4 r VIII-IX
a L.
Cirsium C. arvense (L.) g 3 wr VI-VIII
Scop.
Senecio S. vulgaris L. Ti wr III-XI
Sonchus S. oleráceos T4 wr VI-X
(L.) Gou.
Liliop
sida
Poaceae
Sorghum
S. halepense
(L.)Pers.
Gi s VI
E 13 18 19
Legend: T- terophyta, G - geophyta, r - ruderal species, wr - weed-ruderal
species, S - segetal weeds.
At the studied site, most of the weed species (14; 73.7%) can be
categorized as weed-ruderal plants, with only one (6.3%), Ambrosia
artemisiifolia L., found in a small number, belonging to ruderal plants. Four
(25%) segetal weeds - Hibiscus trionum L., Sinapis arvensis L., Stachys
annua L. and Sorghum halepense L.- are also present at the site.
The biological spectrum of the identified flora is of terophyticgeophytic
character, dominated by terophytes (14; 73.7%)—SI. 1. Within
this group, T4 terophytes, annual plants that germinate in the spring, and
produce ripe seeds in the summer, comprise 63.1% (12 species) of the total
45

Nikolid et al
population. Terophytes Ti and T3 are represented by only one species each
(5.2% of the total, respectively). From the geophyte group, G3 are found,
which are perennial herbaceous plants with adventitious buds on the roots (3
species; 15.8%), and Gi geophyte, with thin underground rhizomes (2;
10.5%). The most abundant weeds in the organically grown maize belong to
the T4 terophyte life form {Datura stramonium L., Chenopodium album L.,
Chenopodium hybridum L., and Solanum nigrum L., as well as Polygonum
lapathifolium L. and Amaranthus retrqflexus L.). These species have
successfully adapted to the agrotechneial measures and the length of the
maize vegetative period in the local climatic conditions; hence, in the
absence of timely suppressive measures, they can achieve their full
lifecycle. In addition to the aforementioned species, G3 geophyte
Convolvulus arvensis L. also finds the local conditions suitable for
development, as, owing to its long roots with numerous adventitious buds, it
too successfully resists the agrotechnical measures.
G3
15.79%
T 1
T3
5,26%
T4
63,16%
Figure 1. Biological spectrum of the weed flora in organic maize production
(2011-2012)
The identified weed species are characterized by a relatively long
flowering period (Tab. 1). Thus, the first species to flower - in March and
April—are terophyte Senecio vulgaris L. and a perennial geophyte
Euphorbia cyparissias L. These are followed by Chenopodium hybridum L.
and Sinapis arvensis L. that flower from May onwards, whilst the flowering
season for the greatest number of species (14) starts in June. In the studied
area, weeding was performed manually, before the onset of flowering and
46

Weed flora under organic maize production conditions
fruiting. Such measures require significant effort and thus increase the
production cost. Nonetheless, when performed in a timely manner, in the
organic farming conditions, they demonstrate good efficacy. Given the
length of the flowering and fruiting period, and other biological advantages
of weed species, it is clear that, in the absence of timely weed control
measures, these plants would successfully produce significant amounts of
seeds that would be deposited in the soil. This is additional negative impact
on maize crop and would adversely impact on the subsequent generation of
crops.
Conclusions
In organic farming, in-depth understanding of weeds, primarily their
biological and ecological characteristics, is an important prerequisite for
successful control of their population and proliferation by mechanical
means, due to the absence of herbicides as the most effective chemical
compounds in combating weed growth.
On the plots under the organic crop production, an integrated
approach to crop protection is mainly applied, which implies use of
agrotechnical measures, crop rotation and biological protective practices
(Kovacevic, 2008; Nikolic et al., 2009). Here, it is necessary to devote
particular attention to monitoring the presence of invasive weeds that may
negatively affect the crop in which they develop, and more broadly,
jeopardize the efforts aimed at the conservation of biodiversity of
indigenous flora of an area and the environmental protection, in general.
Acknowledgements This work was completed as a part of the project TR - 31027
»Organic farming: Improving production using fertilizers, bioproducts and biological
control measures«, funded by the Ministry of Education and Science, Republic of Serbia.
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50

Herbologia, Vol. 13, No. 2, 2012
EFFECT OF CHEMICAL WEED TREATMENT ON WEEDINESS
AND POTATO YIELD
Zoran Jovovic1, Nedeljko Latinovic, Ana Velimirovic1, Tatjana
Popovic1,
Danijela Stesevic2, Dobrivoj Postic3
1 University of Montenegro, Biotechnical Faculty Podgorica
2Faculty of Natural Sciences and Mathematics, Biology Department, Podgorica
3 Institute for Plant Protection and Environment, Belgrade
Abstract
In this paper the results of study of efficiency of combined
application of herbicides in weed control and their effect on yield was done
during 2007 and 2008 in Kolasin (Drijenak village), on acid brown soil, at
an altitude of about 900 m are presented. The following herbicides were
included in the experiment: Acetochlor 900 EC + Prometrin SC 500, Acenit
800 EC + Racer 25 EC, Frontier super + Sencor 70 WP, Sencor 70 WP +
Fusilade Super and Lord 700 WG. The study was conducted in the
Kennebec variety crop (leading potato variety in Montenegro). The control
was not treated with herbicides, and tillage consisted of hilling in the stage
of plant height 15 cm.
All applied herbicides had satisfactory effect in decreasing number
and biomass of weeds. In two years average, Frontier super + Sencor 70 WP
and Sencor 70 WP + Fusilade super (92.3 and 90.3 for number and 88.4 and
92.0 for biomass of weeds) combinations were most effective, and the
weakest effect had combination of Acetochlor 900 EC + Prometrin SC 500
(85.7, 76.8, respectively). In all combinations of herbicides application
significantly higher yield was achieved comparing to the control.
Keywords: weeds, herbicides, potato, yield
Introduction
According to the planted areas, potato is the leading crop in
Montenegro. Potato crop represents more than 20% in total structure of
arable land (Jovovic et al., 2012). Extensive cultivation systems, the use of
inadequate planting material, inadequate selection and poor agricultural
practices, production without irrigation, lack of weed control, and more
frequent occurrence of high summer temperatures and long dry periods, etc.
(Jovovic et al., 2008; Milosevic et al., 2004) are the main reasons why
average potato yield in Montenegro is still low (approximately 15 t.h a ',
http://www.monstat.orgV

Jovović et al.
Weed presence is one of the most important constrains present in
potato production. Although potato has very developed habitus, in early
stages of growth it is very sensitive to weed influence. The very extreme
effect may result in significant reduction of potato yield ranging from 10 up
to 80% (Channappagoudar et al., 2007). As agro technological measures
have high impact on crop weediness in general, control of weeds must be
integrated and based on good knowledge of each factor effect and their
aggregated effect (Božić et al., 1997).
In addition to agricultural practices, great importance has the
application of herbicides in weed control. Herbicides provide not only
efficient but also prompt protection, much longer-term than other
agricultural practices. Application of herbicides provides a safe crop
protection, especially in the early stages of potato growth, i. e. from planting
to foliage covering. This is very important as the crop is most sensitive at
this time to the harmful effects of weeds. For successful control of weeds, a
good knowledge of the composition of the weed flora in various
environmental conditions, and the presence of dominant weed species is
necessary (Šarić, 1988).
Purpose of this research is to analyze effect of applied weed control
measures on potato yield as result of different degree of crop weediness in
agro-ecological conditions of northern Montenegro.
Materials and methods
A study of the effects of combined application of herbicides on
weediness and potato yield was conducted in 2007 and 2008, in Drijenak
(Kolašin), at an altitude of about 900 m. The study was done in the variety
Kennebec (leading variety in Montenegro). The field experiment was in a
random block design with 4 replications. Area of the elementary plot was 21
m2. The previous crop in both years was rye. Potato planting was carried out
manually at a distance 70 x 33 cm, and the density obtained was 43,000
plants per hectare approximately. Ploughing, seedbed preparation and
fertilization was carried out as for the standard potato crop.
Efficiency degree was studied for 8 herbicides in 5 combinations of
application. Type, quantity and method of herbicide applications are shown
in table 1. Herbicides were applied with a dorsal pump CP-3, with
consumption of 600 liters of water per hectare. Evaluation of weed control
was carried out by the method of quantitative and qualitative determination,
on constant square area of 1 m2, in the stage of the full flowering of potato
plants. The efficiency of the applied methods of weed control (%) was
52

Effect of chemical weed treatment on weediness and potato yield
based on a 0-to-100% scale, where 0 = no control and 100 = no living
weeds.
Potato harvesting was done after full maturation of canopy. The
potato yield in the experiment was determined by measuring the tubers at
each elementary plot, and then the yield per hectare was calculated.
Experiments were carried out in acid-brown soil (Table 2), with
following characteristics: acid reaction, pH values in H2O je 5.67, and in
nKCl 4.79; weakly calcareous (1.68% CaCOs), rich in humus (5.07%) and
poor in available phosphorus and potassium (1.9 and 5.5 mg per 100 g,
respectively).
Table 1 - Basic data for applied variants
Trial Herbicide Product Contents Product Application
variant________ applied___________ applied__________o f a. i . ________ rate ________ method
Hi Acetochlor Acetochlor 900 EC 900 g.l'1 2 l.ha'1 PREE
« ___________ Prometrin Prometrin SC 500 500 g.l'1 2 l.ha *_________PREE
§ W2 Acetochlor Acenit 800 EC 800 g.l'1 2 l.ha'1 PREE
p Flurochloridone Racer 25 EC 250 g.l'1 2 l.ha'1 PREE
H 3 Dimetenamid-P Frontier super 720 g.l"1 1 l.ha"1 PREE
!§ Metribuzin Sencor70W P 700 g.kg'1 0.5 kg.ha'1 POST*
^ H4 Metribuzin Sencor 70 WP 700 g.kg"1 0.75 kg.ha'1 PREE
® Fluazifop-p-butil Fusilade super 125 g.l'1 2.5 l.ha'1 POST*
H 5 Metribuzin Lord 700 WG 700 g.kg'1 0.75 kg.ha'1 POST*
______ K Control variant_____________________________________________________________
PREE - Herbicide applied at the pre-emergence stage
POST* - Herbicide applied at the post-emergence stage of crop and weeds (after
hilling)
Weather conditions during the experiment are shown in table 3.
Statistical analysis was done using factorial analysis of variance (ANOVA)
and rating differences between mean values was performed by LSD test.
Table 2 - Chemical characteristics of acid-brown soil on experiment field
Depth (cm) pH CaC0 3 Humus Soluble mg/100 g
H20 nKCl % % P2O5 K20
0-40 5.67 4.79 1 . 6 8 5.07 1.9 5.5
______________ Table 3 - Weather conditions during the experiment_____________
________________________ Month________________________
Year May__________ June________ July_________ August Average
___________________________Air temperature ( C)______________________________
2007 12.8 16.7 18.3 17.5 16.3
53

Jovovic et al.
2008 12.5 16.4 17.2 17.6 15.9
Amount o f rainfall (mm)
Total
2007 136.9 101.0 44.9 16.3 299.1
2008 37.4 103.5 113.5 2 0 . 2 274.6
Results and discussion
In two-years examination of potato, agrophytocenosis in Kolasin
vicinity 24 weed species were registered (23 in 2007 and 18 in 2008).
According to this, the weed communities in the studied area are relatively
poor in species. Perennial species in potato weed species represent 9 or
37.5%, and other species are annual, representing 15 or 62.5% of present
weed species. Monocotyledonous species are 2 (8.3%), and dicotyledonous
species are 22 (91.7%). Analysis of average weediness in control variant
(Table 4) shows that the dominant group of weed species is presented with:
Convolvulus arvensis (23 in 2007 and 21 ind.m'2 in 2008), Chenopodium
album (26 and 14), Polygonum persicaria (14 and 9), Sinapis arvensis (14
and 8), Galinsoga parviflora (13 and 9), Bilderdykia convolvulus (8 and 11),
Amaranthus retroflexus (8 and 11) and Setaria viridis (5 i 9). In the total
weediness of control treatment the weed species above mentioned were
present with 113 ind.m"2 (60.2%), in 2007 and 88 ind.m'2 (78.6%),
respectively. Other weed species were sporadically present and do not have
significance in weed composition.
Table 4 - Structure and number of weeds in potato crop recorded in
control treatments over the period 2007-2008 (ind.m' )
Weed species
Year
2007 2008 2007-2008
Convolvulus arvensis L. 23 2 1 2 2
Chenopodium album L. 26 14 2 0
Polygonum persicaria L. 14 9 11.5
Sinapis arvensis L. 14 8 1 1
Galinsoga parviflora Cav. 13 9 1 1
Bilderdykia convolvulus (L.) 8 1 1 9.5
Amaranthus retroflexus L. 1 0 7 8.5
Setaria viridis (L.) 5 9 7
Other species* 75 24 49.5
Total 188 1 1 2 150
*Agropyron repens, Chenopodium hybridum, Cirsium arvense, Equisetum arvense,
Euphorbia helioscopia, Geranium dissectum, Linaria vulgaris, Plantago lanceolata,
Polygonum aviculare, Polygonum lapathifolium, Rumex acetossela, Stellaria media,
Taraxacum officinale, Trifolium repens, Veronica agrestis and Viola arvensis
54

Effect of chemical weed treatment on weediness and potato yield
Table 5 shows that the highest weediness was noted in the
experiments with the control variant - ind.m"2 150 (188 in 2007 and 112 in
2008). The lowest weediness was found in treatment with Frontier super +
Sencor 70 WP ( H 3 ) - 11.5 ind.m"2 (14 in 2007 and 9 in 2008), and the
highest in the plots with application of Acetochlor 900 EC + Prometrin SC
500 - 21.5 ind.m'2 (27 in 2007 and 16 in 2008).
The results presented in Table 6 show that in the control treatment
the highest weed biomass was measured - 75.8 g.m"2, 88.5 in 2007 and 63.1
in 2008, while the lowest values of this parameter were measured in the
treatment with Sencor 70 WP + Fusilade super ( H 4 ) - 6.1 g.m'2 (8.5 or 3.6 in
two consecutive year of study). The lowest efficiency in the reduction of
weed biomass was obtained in the combination of Acetochlor EC 900 +
Prometrin SC 500 (Hi) - 17.6 g.m'2 (21.5 and 13.7). All herbicide treatments
significantly reduced the weed biomass compared to control variant. Our
results are in agreement with the findings of Phogat et al. (1989) and Lai
(1990).
Table 5 - Efficacy of investigated herbicides (Number of weeds per m2)
Weed species
Other
Variant Year CON CHE POL SIN GAL BIL AMA SET species Total
AR AL PE AR PA CO RE VI
2007 6 2 0 4 1 0 5 3 6 27
H x 2008 3 1 0 2 0 2 2 1 5 16
Average 4.5 1.5 0 3 0.5 1 3.5 2 5.5 21.5
2007 3 0 1 0 0 0 4 3 7 18
h 2 2008 2 0 0 2 2 0 0 2 5 13
Average 2.5 0 0.5 1 1 0 2 2.5 6 15.5
2007 2 1 2 0 0 0 0 1 8 14
h 3 2008 4 0 0 0 0 0 0 0 5 9
Average 3 0.5 1 0 0 0 0 0.5 6.5 11.5
2007 4 1 1 0 0 1 2 2 6 17
H4 2008 1 2 0 2 0 0 1 0 6 1 2
Average 2.5 1.5 0.5 1 0 0.5 1.5 1 6 14.5
2007 3 2 0 3 2 0 3 3 9 25
h 5 2008 2 0 2 1 0 1 0 2 6 14
Average 2.5 1 1 2 1 0.5 1.5 2.5 7.5 19.5
2007 23 26 14 14 13 8 1 0 5 75 188
K 2008 2 1 14 9 8 9 1 1 7 9 24 1 1 2
Average 2 2 2 0 11.5 1 1 1 1 9.5 8.5 7 49.5 150
The two-year average of all applied herbicide combinations
demonstrated high efficacy in reducing weed biomass, which ranged from
55

Jovovic et al.
76.8, in the treatment with Hi to 92, in the treatment H4 (Table 6).
Differences in efficacy in suppressing weed biomass between treatments H 4 ,
H 3 , H 2 and H i and H 5 were statistically justified. Hi combination in
comparison with all other treatments showed the least effect. Metribuzin in
some of our earlier studies showed very high efficacy in reducing infestation
of potato crops (Jovovic et al., 2000, 2006 and 2011). We find high
efficiency of the Metribuzin in the works of Janjic et al. (2000), Trajcevski
et al. (2001), Mircov et al. (2006) and Hoyt and Monks (1996). Mehmeti
(2004) states that this product applied after emergence stage shows higher
efficacy than applied after hilling of the potatoes which is consistent with
this research.
Year
Table 6. Dry biomass of weeds (g)
Variant
K Hi h 2 h 3 H4 h 5
2007 88.5 21.5 1 2 . 2 1 0 . 1 8.5 17.8
2008 63.1 13.7 5.7 7.4 3.6 9.9
Average 75.8 17.6 9 8 . 8 6 . 1 13.9
Along with the reduction of weed biomass all applied methods of
chemical weed control exhibited a very significant impact on reducing the
number of weed species and individuals compared to the controlled
combination. Efficiency coefficient in two-year average varied from 85.7 in
combination with Acetochlor 900 EC + Prometrin SC 500 (Hi) to 92.3
Frontier super + Sencor 70 WP ( H 3 ) . Comparison of applied combinations
did not show statistically significant differences. In the majority of herbicide
treatments efficacy in reducing the number of weed plants were of
approximately same value to those achieved in reducing weed biomass.
Table 7 - Efficacy of investigated way of weed control for weeds
number and dry biomass of weeds_________________________
Efficacy o f Year
Herbicide
investigated
Hi h 2 h 3 H4 h 5
herbicides
2007 85.6 90.4 92.6 91.0 86.7
Weeds 2008 85.7 88.4 92.0 89.3 87.5
number Average 85.7 89.7 92.3 90.3 87.0
Dry biomass 2007 75.7 8 6 . 2 8 8 . 6 90.4 79.9
o f weeds 2008 78.3 91.0 88.3 94.3 84.3
Average 76.8 8 8 . 1 88.4 92.0 81.7
2007 2008 2007/08
56

Effect of chemical weed treatment on weediness and potato yield
Weeds number ls d o .o s -
___________________________________________ l s d o.oi_ _ _ _ _ _ _ :_ _ _ _ _ _ _ :_ _ _ _ _ _ _ _ _ ~
Dry biomass of weeds l s d 005 4.594 6.896 4.816
l s d 0.01 6.280 9.427 6.583
In addition to the demonstrated effectiveness, all applied
combinations of weed control exhibited a significant effect on increasing of
the potato yield (table 8).
Table 8 - Potato yields in experiments (t.ha1)
Year
Variant
K Hi h 2 h 3 H4 h 5
2007. 17.6 25.6 28.1 29.2 30.1 27.1
2008. 19.1 29.5 33.3 32.5 34.2 30.3
Average 18.4 27.6 30.7 30.9 32.2 28.7
2007 2008 2007/08
LSD 0.05 3.203 3.544 2.950
LSD 0.01 4.345 4.808 4.003
The highest yield of tubers, in two-year average, was found in the
treatment H4 - 32.2 t.ha'1, while the lowest yields were measured in the
control variant - 18.4 t.ha'1. The lowest yield was measured in potato crop
treated with herbicide combination Acetochlor 900 EC + Prometrin SC 500
(Hi) - 18.4 t.ha'1, which also had the lowest efficiency in the reduction of
the number and biomass of weeds. Analysis of variance showed that
differences observed in the potato yield in control and all herbicide
treatment were statistically highly significant. Analysis within the herbicide
treatment showed that the difference in yield between the combinations of
tubers H 4 , H 3 , H 2 and H i variants and the combination with H 4 and H 5
variants were statistically justified. Numerous authors observed a favourable
impact of herbicides on the potato tuber yields as a result of eliminating
weed competition (Jaiswal and Lai, 1996; Ackley et ah, 1996; Eberlein et
ah, 1997; Janjic etal., 2006).
From the above said derives that the potato yield were depended on
the efficiency of herbicides and meteorological conditions in the studied
years. The analysis of meteorological data in Table 3 shows that in 2007 and
2008 in terms of average monthly air temperatures and the sum of the
precipitation during the potato growing season were quite equalized. Higher
average potato yields were obtained in 2008, which is explained by the fact
that in this year distribution of rainfall was more favorable. The higher
amount of rainfall at the beginning of the growing season in 2007 caused the
poor vegetative growth of potato plants, and thus a weaker competitive
57

Jovović et al.
ability. Potatoes require moisture throughout the growing season, but
excessive water can be undesirable and result in significantly reduced
yields.
Conclusions
Based upon the research, following can be concluded:
1. All applied method of weed control showed very high level
of efficiency in reducing the number and biomass of weeds.
2. Efficiency in decreasing the number of weed individuals and
their biomass was almost the same for all studied herbicides.
3. In the two-year average all applied herbicide combinations
had high efficiency in decreasing weed biomass varying from 76.8, in
acetochlor 900 ec + prometrin sc 500 (hi) treatment to 92, in sencor 70 wp +
fusilade super (h4) treatment.
4. All methods of chemical weed control were effective in terms
of decreasing the number of weed species and weed individuals comparing
to the control, efficiency coefficient in two years average was from 85.7 for
combination acetochlor 900 ec + prometrin sc 500 (hi) to 92.3 frontier super
+ sencor 70 wp (I13). comparison of applied herbicide treatments did not
show statistically significant differences.
5. The highest potato yield, two years average was measured in
combination sencor 70 wp + fusilade super (h4) - 32.2 t.ha'1,while the
lowest yield was measured in control - 18.4 t.ha"1. significantly higher
potato yield was achieved when herbicides were applied, in all combinations
comparing to the control.
Literature
ACKLEY, J. A., WILSON, H. P., HINES, T. E., 1996: Efficiacy of rimsulfuron and
metribuzin in potato (Solatium tuberosum L.). Weed Technology, 10, p. 475—480.
BOŽIĆ, D., KOVAČEVIĆ, D., MOMIROVIĆ, N., 1997: Agricultural systems and their
importance in weed control. Contemporary problems in herbology, 153-173,
Beograd.
CHANNAPPAGOUDAR, B.B., BIRADAR, N.R., BHARMAGOUDAR, T.D. AND
KOTKARNATAKA, R. V., 2007: Crop weed competition and chemical control of
weeds in potato. J. Agric. Sci., 20 (4), 715-718.
EBERLEIN, C. V., PATTERSON, P. E., GUTTIERI, M. J., STARK, J. C., 1997: Efficacy
and economics of cultivation for weed control in potato (Solanum tuberosum L.).
Weed Technology, 11, p. 257-264.
HOYT, G.D., MONKS, D.W., 1996: Weed management in strip-tilled Irish potato and
sweetpotato systems. Hort technology, 6 (3), 238-240.
JAISWAL, V. P., LAL, S. S., 1996: Efficacy of cultural and chemical weed control
methods in potato. Journal of Ind. Pot. Ass., 23,20-25.
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Effect of chemical weed treatment on weediness and potato yield
JANJIÔ V., MILOSEVIC, D., BALOVIÔ, I. (2006): Investigation of rimsulfuron efficacy
in potato crop in different agroecological conditions. Plant Protection. Vol. XVII,
No. l.pp. 145-153
JANJIC, V., STANKOVIC-KALEZIC, RADMILA, MARINKOVIC, IVANA, 2000: Study
of rimsufuron effectiveness in potato crop, VI Weed congress, Abstract book, 481 -
487, Banja Koviljaca.
JOVOVIÉ, Z., DOLIJANOVIÉ, Z., KOVAÊEVlé, D., VELIMIROVIC, ANA,
BIBERDZlC, M., 2012: The productive traits of different potato genotypes in
mountainous region of Montenegro. Genetika, Vol. 44, No 2, 389-397, Belgrade.
JOVOVlC, Z., LATINOVlC, N., STE§EVlC, DANIJELA, 2011: Efficiency of metribuzin
in weed control in potato crop in the dependence of dose and time of application.
Herbology, Vol. 12, No 2, 7-14, Sarajevo.
JOVOVIC, Z., STESEVIC, DANIJELA, MOMIROVIC, N., MILOSEVIC, D., DALOVIC,
I., 2006: The impact of different ways of weed control on the weediness and the
potato seed crop yield near Pljevlja. Scientific papers of Faculty of agriculture,
XXXVIII, 591-597, Temiçoara, Romania.
JOVOVIC, Z., BIBERDZIC, M., SPALEVIC, V., MITROVIC, D., 2000: Influence of
some herbicide and their combination on weed and yield of seed potatoes, Archive
of agricultural science. 61, No 215, 239-254, Belgrade.
LAL, S.S., 1990: Efficacy of herbicides for weed control in potato in Meghalaya Hills.
Journal of Indian Potato Association, 17:48-51.
MEHMETI, A., 2004: Three years effect of herbicide on weed flora and potato yield,
Herbology, Vol. 5, No. 1, 85-94, Sarajevo.
MILOSEVIC, D., IVANOVIC M., IVANOVIC, M., 2004: Epiphytotic fire blight in tomato
and potato in Serbia and possible forecasts. VIII Scientific-expert symposium
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potatoes, Herbologia, Vol. 7, No. 1, 3-7, Sarajevo.
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efficiency of different herbicides with cultural practices in potato. Indian Journal
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SARlC, T., 1988: Weeds and Their Control by Herbicides, Zadrugar, Sarajevo.
59

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60

Herbologia, Vol. 13, No. 2, 2012
PLANT COVER OF NATURAL PASTURE LOCATED IN THE
VICINITY OF THE TOWN OF BOČAR
Aleksa Knežević, Branka Ljevnaić-Mašić, Dejana Džigurski,
Branko Ćupina
Faculty of Agriculture, University of Novi Sad,
Trg D. Obradovića 8 , 21 000 Novi Sad, Serbia
e-mail: brana@poli.uns.ac.rs
Abstract
The plant cover of the natural pasture on the solonetz and saline
smonitza located in the vicinity of the town of Bočar (Serbia - the
Vojvodina Province - Banat) are characterized by 135 taxa (119 species, 5
subspecies, 4 varieties, 6 forms and 1 lusus). 126 taxa were listed i.e. 119
species, 5 subspecies and, because of their ecological characteristics, two
varieties Aster tripolium L. var. pannonicus (Jacq.) Beck and Glyceria
fluitans (L.) R. BR. var. poaeformis Fies. These varieties were put on the list
because their higher taxonomic categories were not found in the studied
flora. Specific features of the plant cover of the studied area are result of
their ecological, phytocoenological and plant-geographic characteristics.
Ecological characteristics result from 42 halophyte taxa (33.33%) with the
ecological index S+. Phytocoenological elements are stands of one
phytocenoses from Phragmitetea Tx. et Prsg. 1942 class (Ass.
Bolboschoenetum maritimi continentale) and ten phytocenoses from
Festuco-Puccinellietea Soó 1968 class (Ass. Puccinellietum limosae, Ass.
Pholiuro-Plantaginetum tenuiflorae, Ass. Hordeetum histricis, Ass.
Camphorosmetum annuae, Ass. Agrostio-Alopecuretum pratensis, Ass.
Agrostio-Beckmannietum, Ass. Agrostio-Eleochariti-Alopecuretum
geniculati, Ass. Halo-Agropyretum repentis, Ass. Artemisio-Festucetum
pseudovinae i Ass. Achilleo-Festucetum pseudovinae). Plant-geographic
characteristics of studied area are endemic species of Pannonian Plain
Plantago schwarzenbergiana Schur and Statice gmelini subsp. hungaricum
(Klokov) Soó and also subendemic species of Pannonian Plain Puccinellia
limosa Holmb. and Roripa kerneri Menyh. Based on 33.33% of recorded
taxa, which are characterized by S+, stands of 11 phytocenoses that are
characteristic of saline sites and the presence of two Pannonian and two

Knežević et al.
Subpannonian elements of flora we can conclude that natural pasture
located in vicinity of the town of Bočar (Banat-Serbia) is part of halobiom
of the Pannonian Plain region.
Keywords: natural pasture, saline, flora, vegetation, Bočar (Vojvodina province - Serbia)
Introduction
Due to their poor soil properties, continental salt marshes are, in
terms of crop production, unused or underused land. In addition to being
suitable for growing aromatic and medicinal plants and the development of
agro-forestry, they are also important as natural pastures (Li et al., 2008). In
the Pannonian Plain, known as the granary of the Central European region,
on the continental salt marshes, due to their low organic production,
relatively well-preserved natural vegetation cover, commonly used as a
natural pasture, has survived (Slavnić, 1948; Bodrogkoozy, 1966, 1970;
Godicl; 1980; Sadovsky et al., 2004; Patrut et al., 2005; Purger 2006).
Studies on pasture flora on saline soils in Vojvodina stem from the floristic,
vegetation, phytogeographical and ecological research (Parabućski, 1980;
Knežević, 1980, 1984, 1994; Vučković, 1985; Knežević et al., 1998, 2005,
2012).
In addition to plants and plant communities adapted to the increased
salt concentration in the flora of natural grasslands, their ecological
conditions are also suitable for successful growth and development of nonhalophytic
species. That is why the salt marshes of this region, especially
when surrounded by arable land, are an important refuge (asylum) for taxa
characteristic for weed and ruderal flora and vegetation. Weed and ruderal
taxa represented in this flora are very important, as they support part of, or
an entire, lifecycle of many organisms (insects, fungi, nematodes and
viruses) that, as pests or disease agents, significantly contribute to the
reduction in the yield (crop, vegetable, fruit, grape and horticultural) of the
surrounding cultivated land (Knežević et al., 2002, 2010; Ljevnaić-Mašić et
al., 2011).
For this reason, floristic, vegetation, phytogeographical and
ecological studies of salt marsh pasture flora in Vojvodina is important for
62

Plant cover of natural pasture located in the vicinity of the town of Bocar
weed research and broadening the extant knowledge on the development of
pests and pathogens in cultivated plants.
The aim of this study was to establish flora, vegetation and plantgeographic
characteristics of the natural pasture located in the vincitz of the
town of the Bočar (Serbia - the Vojvodina Province - Banat).
Material and methods
The data about studied pasture land are according to Benka and
Salvai (2005). The data about the climate of the studied area according to
Ljevnaić-Mašić (2010). The data on the natural plant cover of the pastures
located in the vicinity of Bočar combine a part of the results of a previous
study of plant cover of saline soils of Banat (Knežević et al., 2008) and the
results of studies conducted 2010-2011. years in the location mentioned
above. The observed plants were determined and their names identified in
accordance with the nomenclature in Josifović (1970-1976), Savulescu
(1952-1976) and Tutin et al. (1964-1980). Values of the salinity index of the
observed taxa were estimated according to the criterion of Landolt (Landolt,
1977. The taxa that had not been characterized by Landolt were
characterized by Knežević (1994). Whereas taxon Hordeum asperum
(Simk.) Deg. in these publications is not characterized with ecological
indices of salinity sites, its suitability we are characterized with S.. The
syntaxonomic position of the observed plant communities at the natural
pasture located in the vicinity of Bočar was defined according to Knežević
et al. (1998). The listed taxa were divided according to endemic and
subendemic of Pannonian Plain region on the basis of publications of Soo
(1964-1985).
Studied area
Bočar is a town in Pannonian part of Serbia (Vojvodina Province -
Banat), Fig. 1. A climate diagram after Walter made on the basis of the data
from the meteorological station in Kikinda shows that studied area has a
semi-arid unfavorable period from mid-July to late September (Ljevnaić-
Mašić, 2010). Due to weak organic production, south and southwest of the
town Bočar are the raw surface of solonetz and saline smonitza. In these
areas grows poor plant cover, which the locals used as natural pasture.
63

Knežević et al.
Fig. 1. Map of Vojvodina Province (Northern Serbia) with the location of
the investigated site
Results and discussion
Flora of saline sites on the solonetz and saline smonitza located in
the vicinity of the town of Bočar:
64

Plant cover of natural pasture located in the vicinity of the town of Bocar
1. Achillea millefolium L. ISJ,
2. A. setacea W. et K. ISJ,
3. Agrimonia eupatoria L. ISJ,
4. Agropyrum repens (L.) Beauv.
IS+J,
5. Agrostis alba L. ISJ,
A. alba L. f. coarctata Rchb.,
6. Alisma lanceolatum With. ISJ,
7. A. plantago-aquatica L./S./,
8. Alopecuros geniculatus L. /S+/,
9. A. pratensis L. ISJ,
10. Anagallis femina Mill. ISJ,
11. Artemisia marítima L. subsp.
monogyna (W. et K.) Gams. /S+/,
12. Aster tripolium L. var.
pannonicus (Jacq.) Beck /S+/,
13. Atriplex tatarica L. IS+I,
14. Beckmannia eruciformis (L.)
Host/SV,
15. Bolboschoenus maritimus (L.)
Palla /S+/,
16. Bromus commutatus Schrad.
ISJ,
17. B. mollis L. ISJ,
18. Bupleurum tenuissimum L.
ISJ,
19. Butomus umbellatus L. ISJ,
20. Calamagrostis epigeios (L.)
Roth. ISJ,
21. Camphorosma annua Pall.
IS+I, C. annua Pall. f. nana Moq.
22. Carduus nutans L. ISJ,
23. Carex distans L. IS+I,
24. C. vesicaria L. ISJ,
25. C. vulpina L. ISJ,
26. Centaurium umbellatum Gilib.
ISJ,
27. Cerastium caespitosum Gilib.
ISJ,
28. C. dubium L. (Bast.) Schwarz.
ISJ,
29. Chenopodium rubrum L.
subsp. botryoides Sm. IS+I,
Ch. rubrum L. subsp. botryoides
Sm. var. crassifolium (Horn.)
Kov.
30. Ch. vulvaria L. ISJ,
31. Cichorium intybus L. ISJ,
32. Cirsium arvense (L.) Scop./S.
/,
33. C. lanceolatum (L.) Scop. ISJ,
34. Convolvulus arvensis L. ISJ,
35. Cynodon dactylon (L.)Pers./S.
/,
36. Dactylis glomerata L. ISJ,
37. Daucus carota L. ISJ,
38. Dipsacus laciniatus L. ISJ,
39. Eryngium campestre L. IS J,
40. Euphorbia cyparisias L. ISJ,
41. Festuca vallesiaca Sch. subsp.
pseudovina (Hack.) A. et G. IS+I,
42. Fragaria viridis Dúchense IS .
/,
43. Galium aparine L. IS J,
44. G. verum L. IS J, G. verum L.
f. spiculifolium Schur
45. Glyceria fluitans (L.) R. Br.
var. poaeformis Fries. IS+I,
46. Gypsophila muralis L. IS J,
47. Heleocharis palustris(L.)R.Br.
ISJ,
48. Hordeum asperum (Simk.)
Deg. ISJ,
49. H. maritimum Stokes subsp.
gussoneanum (Pari.) A. et G. IS+I,
50. Hypericum perforatum L. IS J,
51. Inula britannica L. /S+/,
52. Juncus compressus Jacq. IS+I,
65

Knezevic et al.
J. compresus Jacq. var.
compressus f. porphyrocarpus J.
Murr.
53. J. conglomeratus L. /S V,
54. J. gerardi Lois. /S+/,
55. Lactuca saligna L. /S+/,
56. Lathyrus aphaca L. /S V,
57. L. hirsutus L. /S V,
58. L. tuberosus L. /SV,
59. Lepidium draba L. /SV,
60. L. ruderale L. /SV,
61. Lolium perenne L. /S 7,
62. Lotus corniculatus L. /SV,
63. L. tenuis Kit. /S+V,
64. Lycopus europaeus L. /SV,
65. L. exaltatus L. /SV,
66. Lysimachia nummularia L./S.
/,
67. Lythrum salicaria L. /SV,
68. L. virgatum L. /SV,
69. Marrubium peregrinum L. /S.
/,
70. M vulgare L. /SV,
71. Matricaria chamomilla L.
/SV,
M. chamomilla L. f. salina
(Schur) Jáv.
72. M. inodora L. /S+/,
73. Medicago falcata L. /SV,
74. M lupulina L. /SV,
75. Melilotus officinalis (L.)
Pallas /SV,
76. Mentha pulegium L. /S+/,
77. Myosurus minimus L. /SV,
78. Oenanthe silaifolia M.B. /S+/,
79. Ononis spinosa L. /SV,
80. Ornithogalum gussonei Ten.
/SV,
81. Panicum crus-galli L. /SV,
82. Pastinaca sativa L. /SV,
83. Pholiurus pannonicus (Host)
Trin. /S+/,
84. Phragmites communis Trin.
/S+/,
85. Plantago lanceolata L. (S.),
P. lanceolata L. var.
sphaerostachya M. et K.,
86. P. schwarzenbergiana Schur
/S+/,
87. P. tenuiflora W. et K. /S+/,
P. tenuiflora W. et K. f.
depauperata Domin
88. Poapratensis L. /SV,
89. Podospermum canum C. A.
Mey. /SV,
90. Polygonum aviculare L. /SV,
91. Portulaca oleracea L. /SV,
92. Potentilla argentea L. /SV,
93. P. reptans L. /SV,
94. Prunella vulgaris L. /SV,
95. Prunus spinosa L. /SV,
96. Puccinellia limosa (Schur)
Holmb. IS+/,
97. Pulicaria vulgaris Gärtn. /S+/,
98. Ranunculus lateriflorus DC
/S+/,
99. 7?. sardous Cr. /S+/,
100. Roripa austriaca (Cr.) Bess.
/SV,
101. i?, kemeri Menyh. /S+/,
102. Rumex crispus L. /S+/,
103. i?, patientia L. /SV,
104. Salvia nemorosa L. /SV,
105. Schoenoplectus lacuster (L.)
Palla/SV,
106. Setaria viridis (L.) P.B. /SV,
107. Sinapis arvensis L. /SV,
108. Spergularia media (L.) Presl.
/S+/,
109. Statice gmelini Willd. subsp.
hungaricum (Klokov) Soó (S+),
66

Plant cover of natural pasture located in the vicinity of the town of Bocar
110. Stenactis annua (L.) Ness./S.
/,
111. Suaeda maritima (L.) Dum.
IS+I,
112. Symphytum officinale L. ISJ,
S. officinale L. 1. albiflorum
Kirschl.
113. Trifolium angulatum W.et K.
ISJ,
114. T. arvense L. ISJ,
115. T. campestre Schreb. ISJ,
116. T. pratense L. ISJ,
117. T. repens L. ISJ,
118. T. striatum L. IS+I,
119. Typha angustifolia L. /S+/,
120. Typhoides arundinacea (L.)
Mnch. ISJ,
121. Verbascum blattaria L. /S+/,
122. Verbena officinalis L. ISJ,
123. Veronica anagallis-aquatica
L. ISJ,
124. V scutellata L. ISJ,
125. Vulpia myuros (L.) Gmel. IS.
/
126. Xanthium italicum Moretti
IS+I.
67

Knežević et al.
Of the 135 registered taxa (119 species, 5 subspecies, 4 varieties, 6
forms and 1 lusus), 126 were listed as separate species. The latter croups
comprised 119 species, 5 subspecies and, because of their ecological
characteristics, 2 varieties (Aster tripolium L. var. pannonicus (Jacq.) Beck
and Glyceria fluitans (L.) R. BR. var. poaeformis Fies.). These varieties
were put on the list because their higher taxonomic categories were not
found in the studied flora.
The 9 unlisted taxa had a lower taxonomic rank than subspecies, and
we registered their higher taxonomic categories in the studied flora. This
group included 2 varieties (Chenopodium rubrum L. subsp. botryoides Sm.
var. crassifolium (Horn.) Kov. and Plantago lanceolata L. var.
sphaerostachya M. et K.), 6 forms (Agrostis alba L. f. coarctata Rchb.,
Camphorosma annua Pall. f. nana Moq., Galium verum L. f. spiculifolium
Schur, Juncus compresus Jacq.var. compressus f. porphyrocarpus J.Murr.,
Matricaria chamomilla L. f. salina (Schur) Jáv. and Plantago tenuiflora W.
et K.f. depauperata Domin) and one lusus (Symphytum officinale L. 1.
albiflorum Kirschl.).
Ecological characteristics of plant cover result from 42 halophytes
(33.33%) with the ecological index S+.
Therefore, in the natural flora of pasture located in the vicinity of the town
of Bočar percentage of halophytes is smaller than in the natural flora of
pastures in the vicinity of the town of Novalja - Salt Kopovo (Knežević et
al., 2005) and Kumanovo (Knežević et al., 2009), and higher than in flora of
natural pastures in the vicinity of in the town of Kneževac (Knežević et al.,
2011) and Elemir - Okanj (Knežević et al., 2012).
The taxa found in the natural pasture located in the vicinity of the town of
Bočar formed stands of 11 plant communities whose sintaxonomic position
are:
Class Phragmitetea Tx. et Prsg. 1942
Order Bolboschoenetalia maritimi Hejny 1967 p.p. (Bolboschenetea
maritimi Tx. 1969, Scirpetalia maritimi Borhidi 1970 p.p.)
68

Plant cover of natural pasture located in the vicinity of the town of Bocar
Alliance Bolboschoenion maritimi continentale Soö (1945) 1947 emend.
Borhidi 1970
Ass. Bolboschoenetum maritimi continentale Soô (1927) 1957 (

Knezevic et al.
Ass. Achilleo-Festucetum pseudovinae (Magyar 1928) Soo 1945.
The stands of ass. Bolboschoenetum maritime continentale
overgrown edges of canals and rare large deep depressions. During the
vegetation period their sites are a long time under the surface water or with
high groundwater level. This plant cover of the pasture cattle avoid to graze
and farmers do not mow. There are dominated Bolboschoenus maritimus
and Schoenoplectus lacuster, and also Phragmites communis, Typha
angustifolia, Alisma plantago-aquatica and Veronica anagallis-aquatica.
Due to surface erosion, the stands of the communities from the
alliance Puccinellion limosae i.e. the stands of ass. Puccinellietum limosae,
Pholiuro-Plantaginetum, Hordeetum histricis and Camphorosmetum
annuae overgrown shallow, saline and smaller depressions. After a brief
spring flooding, these sites are much shipping dry in the later part of the
vegetation period. Their plant cover, which is low, limited, poor with
species and with low ground cover, is negligible for the grazing of livestock.
The stands of the communities from the alliance Halo-Agrostion
albae pannonicum i.e. the stands of ass. Agrostio-Alopecuretum pratensis,
Agrostio-Beckmannietum and Agrostio-Eleochariti-Alopecuretum
geniculati overgrown slightly saline bottom of more spacious depressions.
During early spring, due to the high groundwater level, in these depressions
the soil moisture is significant. This is the period of their the greatest
nutritional value but also the period of the most intensive grazing which
causes waterlogging due to livestock trampling. Therefore, mowing of this
stands is not profitable. Only in some spacious and preserved sites of the stands
of ass. Agrostio-Alopecuretum pratensis the mowing by machine is present,
but grazing in later period in these areas is very scarce.
The stands of the communities from the alliance Festucion
pseudovinae i.e. the stands of ass. Halo-Agropyretum repentis, Artemisio-
Festucetum pseudovinae and Achilleo-Festucetum pseudovinae are the
plant cover developed on the highest parts of the pasture which are usually
out of reach groundwater during the vegetation period.
The stands of the ass. Halo-Agropyretum repentis are the
degradation stages of the stands of ass. Achilleo-Festucetum pseudovinae.
70

Plant cover of natural pasture located in the vicinity of the town of Bocar
Their development, on the wetter sites, is caused by intensive grazing and
sometimes by farming efforts undertaken at these sites. Therefore, these
sites had acquired characteristics of ruderal vegetation developing on a
slightly saline soil. The cutting yields are modest, hay is medium quality
and grazing in later period is poorly productive.
The stands of the ass. Achilleo-Festucetum pseudovinae is
predominant type of plant cover. Salts which are rinsed from the surface
layers of soil are causes the development of this stands. Their floristic
composition, in addition to the species that are typical of the meadow-steppe
vegetation of the continental salinas (halophytes) from the class Festuco-
Puccinellietea, includes plant species that comprise the humid meadows
from the class Molinio-Arrhenatheretea, which are present in the early
spring, and the species that comprise the dry meadows from the class
Festuco-Brometea, which develop later in the season. These sites are good
hayfields early in the spring, and best pasture afterwards.
The stands of the ass. Artemisio-Festucetum pseudovinae are also
degradation stages of the stands of the ass. Achilleo-Festucetum
pseudovinae. Their development, on slightly drier sites, is caused by a
poorly developed (often destructive) surface layer of soil. Therefore, the
cutting yields are modest, hay is poor quality and grazing on them is scarce.
Conclusions
The plant cover on sites of the natural pasture on the solonetz and
saline smonitza located in the vicinity of the town of Bocar are
characterized by 135 taxa. This plant cover is ecological, phytocoenological
and plant-geographic specific. Ecological characteristics result from 42
halophyte taxa (33.33%) with the ecological index S+. Phytosociological
specificity consists 11 phytocoenoses. Class Phragmitetea is present by one
phytocenoses (Bolboschoenetum maritimi continentale). Class Festuco-
Puccinellietea is present by ten phytocenoses (Puccinellietum limosae,
Pholiuro-Plantaginetum tenuiflorae, Hordeetum histricis,
Camphorosmetum annuae, Agrostio-Alopecuretum pratensis, Agrostio-
Beckmannietum, Agrostio-Eleochariti-Alopecuretum geniculati, Halo-
Agropyretum repentis, Artemisio-Festucetum pseudovinae and Achilleo-
Festucetum pseudovinae). Plant-geographic characteristics are endemic
71

Knežević et al.
species of Pannonian Plain Plantago schwarzenbergiana and Stotice gmelini
subsp. hungaricum and also subendemic species of Pannonian Plain
Puccinellia limosa and Roripa kerneri. Taking in consideration the presence
of 42 halophyte taxa (33.33%), the presence phytocoenoses typical for
saline sites and the presence of two Pannonian and two sub-Pannonian
endemic species it was concluded that the studied pasture located in the
vicinity of the town of Bočar (Banat - Serbia) is part of the halobiome of the
Pannonian Plain.
Acknowledgement This study is part of the project TR31016 »Improvement of field
forage crops agronomy and grassland management« supported by the Ministry of
Education and Science of the Republic of Serbia.
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74

Herbologia, Vol. 13, No. 2, 2012
WEED COMPOSITION AND DIVERSITY OF ORGANIC AND
CONVENTIONAL MAIZE FIELDS IN jASZSAG REGION, IN
HUNGARY
Preliminary Communication
Zita Dorner, Phan Quoc Nam, Mark Szalai, Mihaly Zalai, Zsuzsanna
Keresztes
Plant Protection Institute, Faculty of Agricultural and Environmental Sciences,
Szent Istvan University, 2100 Godollo, Hungary
Domer.Zita@mkk.szie.hu
Abstract
This study analyzes weed flora of maize crop in organic fields of
Tamamenti farm in Jaszdozsa and neighbouring areas where maize was
managed by conventional techniques. The aim was to find out the dominance
of weed species (based on cover %) in the fields. In addition, analysing the
influence of farming systems and effects of sampling times on weed flora
were made, and the interaction between farming systems and sampling times
was also analyzed.
Weeds were assessed in lx l sample quadrates randomly placed
within the fields. Assessments were made three times during the maize
growing season in 2011. Cover of weeds on species level was directly
recorded by visual estimation.
There were differences between weed species found in organic fields
and conventional fields. The most dominant weed of both organic and
conventional fields was Echinochloa crus-galli. Average total weed cover
and diversity index of organic maize fields were higher than those in
conventional fields. The effect of farms was significant both on weed cover
and on diversity index. Effects of sampling times on weed cover were
significant but insignificant on diversity index. Number of weed species
depended on farming systems, but not depended on sampling times. A
significant interaction between farms and sampling times on weed cover and
on diversity index were found.
Keywords: farming systems, maize, weed flora, weed cover, weed diversity

Domer et al.
Introduction
The organic approach differs from the conventional farming in lots of
attribute because these farming systems are diverse in their cultivation
structure. For example, the use of pesticides and fertilizers is not allowed in
some systems. Chemicals can be only used in integrated and conventional
systems but their use is forbidden in organic farming. Avoiding the use of
pesticides and fertilizers can result in differences of the weed flora.
Organic farming system was established in the 1980s, to concern with
the environment conserving, healthy food, and environmental friendly
producing techniques. Thus, high yield or quantity is not the most deciding
factor of organic farming productions, quality became the most important
factor (Zalai et al., 2009). In organic maize farms, weeds are important yield
loss factors. They compete with maize for light, water and nutrition reserve in
the soil. Moreover, weeds are the intermediate hosts of crop pathogens which
can decrease the income of production due to yield loss and lower quality.
The most challenging aspect of organic crop production is to prevent
weed infestation. If weeds are controlled mechanically, the abundance of
summer annuals can increase (van Elsen, 2000). The presence of high weed
densities in arable fields can cause significant loss of crop yield and quality
(Christensen, 1993). The yield loss levels depend on weed species, densities
and time of weed emergence compared to the maize crop. Weeds that emerge
together with maize or shortly afterwards cause greater yield loss than weeds
emerging later in the growth cycle of the crop. For example, common
barnyard grass (Echinochloa crus-galli) density of 200 plants m2 reduced
maize yield in the range from 26 to 35% when the emergence of barnyard
grass seedlings occurred between the 1 and 2 leaf stage of maize growth
(Bosnic and Swanton, 1997). The same density, however, resulted in only 6%
yield loss when barnyard grass seedlings emerged after the 4 leaf stage of
maize growth. Importance of time of weed emergence relative to the crop is
very important and described by the critical period for weed control (Raj can,
2001). The critical period is usually defined as growth stages being most
vulnerable to weed competition. In practice, this is referred as the number of
weeks after maize emergence during which the crop must be free of weeds to
prevent yield losses above 5%. This usually ranges 1-8 weeks after crop
emerges (Hall et al., 1992). As for weed densities, the competitive threshold
is used. This is defined as the weed density above which crop yield is
reduced beyond an acceptable amount (Rajcan, 2001). Percentage maize
yield losses ranged from 5% to 34% for redroot pigweed (Amaranthus
retroflexus L.) densities of 0.5-8 plants m'2 (Rajcan, 2001), whereas quack
grass (Elytrigia repens L.) densities of 65, 390 and 745 shoots m'2 reduced
maize yield by 12%, 16% and 37%, respectively. Ambrosia artemisiifolia can
76

Weed composition and diversity of organic and conventional maize fields .
cause considerable yield losses due to competing for light, nutrients and
water reserves in soils. In field experiments, at plant densities 1 m"2, A.
artemisiifolia can cause maize yield losses 0.235 ton ha'1and yield loss 42-54
%, 62 % and 70-71 %, at a weed density of 9, 18 and 26 plants m'2,
respectively (Varga et al. 2002). In another comparable experiment, A.
artemisiifolia at densities of 1 and 2-10 plants m"2 caused 25%, 30-33% yield
losses, respectively (Kazinczi et al., 2007). Abutilón theophrasti reduced the
yield of maize by 31.6% compared with weed-free plots (Kazinczi et al.,
1991). Experiments investigated the competition between Datura
stramonium and maize under field conditions showed that weed densities of
1, 2, 5 and 10 plants m'2, the yield decreased by 31%, 43%, 59% and 63%,
respectively. Competition between Xanthium species and maize crops was
also investigated. Xanthium italicum had the strongest competitive ability
compared with other weed species. At weed densities of 1, 2, 5 and 10 plants
m'2, it caused 87, 82, 96 and 94 % yield losses of maize compared to weedfree
plots. Xanthium strumarium at weed densities of 5 and 10 plant m'2
resulted in 62 and 64 % yield losses of maize (Novák, 2009).
Many recent researches about weed flora of organic farms showed
that organic farming system enhances biodiversity. The diversity of flora is
higher in organic farms than in conventional ones (Kaar and Freyer, 2008).
Using no chemical fertilizers and synthetic herbicides can result in changing
weed composition and density. Organic cropping has been found to support
populations of endangered weed species (Rydberg and Milberg, 2000);
however, the use of herbicides was found to increase the abundance and
number of broad-leaved weed species (Moreby et al., 1994). A lower rate of
nitrogen fertilization was reported to be favourabel for non-nitrophilous
species (Rydberg and Milberg, 2000) and legumes, while the composted
manure has been favoured by nitrophilous species, Chenopodiaceae in
particular (van Elsen, 2000). Weed abundance, species richness and diversity
were lower in conventional fields, where weeds were controlled typically by
herbicides, than in organic fields (Romero et al., 2005). In Hungary, several
studies proved that number of weed species and their total cover were higher
in organic farming systems than in conventional farming systems (Domer,
2006; Zalai, 2011; Domer and Zalai, 2009).
The specific weed community of a field is influenced not only by
climate, soil conditions but also by agricultural technologies in both maize
and previous crop. Therefore, different weed control strategies were needed
to apply in different areas (Berea, 2004). Thus, simply copying of weed
control strategies should not be advised for another area where different
natural conditions and farming technologies can be found. For this reason,
77

Domer et al
different weed assessments are necessary in each farm to improve appropriate
weed control strategies and effective weed control methods.
M aterial and methods
Study was carried out at Tamamenti farm and neighbouring area
which had the same soil type and natural conditions but different agricultural
technologies. Tamamenti farm is located in Jaszdozsa, Central Hungary. In
the farm, there is 1700 ha arable land for plant cultivation such as winter
wheat, spelled, winter barley, oats, winter peas, sunflower, oilseed rape,
maize, oil pumpkin, alfalfa and grass ley. Soil type is chernozem. Weed
control in organic fields were exclusively done by mechanic controls.
Ploughing was done after harvest of previous crop, and followed by
harrowing after 3 weeks. In studied conventional fields the cropping system
was less diverse, conventionally crop rotation included only five annual
crops: winter wheat, winter barley, maize, sunflower and oilseed rape. Weeds
were controlled by soil tillage and herbicides (88 g ha'1tembotrion + 44 g ha"
1izoxadifen-etil in 21 ha'1Laudis) used at 4-6 leaf stage.
Weed assessments were made three times in 2011: first at 14 June,
second at 27 July and the third at 9 September in each studied field. Method
based on the evaluation of covering percentage was used, which has the
advantage of being simple and quick (Zalai et al., 2012). In each assessment,
sampling quadrates of lx l metre were placed randomly, and weed cover was
assessed by visual estimation used the cover percentages of the weed species.
Eight sample quadrates were recorded in each field. All sample quadrates
were placed at least 2 meter distance from the field edges to avoid edge
effects. Sampling was made in four maize fields: 2 organic fields and 2
conventional fields. Total of 32 sample quadrates were assessed each
sampling time, equalled as 96 sample quadrates for the entire study.
All data including number of weed species and weed cover that were
collected from three sampling times in both organic and conventional maize
fields were used for the analyses. Statistical analyses were made by SPSS
program (SPSS 12.0, SPSS Inc) with 95% confidence level. General linear
model was fitted to investigate influence of farming systems and sampling
times on weed cover. The interaction between farming system and sampling
times was also analysed. To investigate diversity of weeds in fields,
Shannon’s diversity index was used (Shannon, 1948; Fig. 1). It is based on
the number of species and their relative abundance (here: relative cover).
78

Weed composition and diversity of organic and conventional maize fields .
H ' = -
R
i — 1
Pi lo§ Pi
Figure 1: The formula of Shannon’s diversity index (R: number of species;
Pi: the proportion of the ith species of all species)
Results and discussion
There were differences between weed species occurred in organic
fields and conventional fields. Echinochloa crus-galli was the most dominant
weed of both organic and conventional fields. Ambrosia artemisiifolia cover
ranked as the second in organic fields; however, this species was absent in
conventional ones. Setaria pumila cover ranked as the fourth in organic
fields, and as the second in conventional fields; although, these covers were
quite close with 1.013% and 1.019% in conventional fields and organic ones,
respectively. Convolvulus arvensis had the third rank of conventional fields,
the eighth of organic fields; however, the cover in organic fields was higher
than in conventional fields. Many weeds such as Ambrosia artemisiifolia,
Persicaria lapathifolia, Datura stramonium, and Lathyrus tuberosus were
recorded in organic fields but were absent in conventional fields (Table 1).
The main reason for their absence could be the herbicide application which
could eliminate non-tolerant species. Beside the different weed control
practice, the weed flora could be also different because of the slightly
different crop rotation of organic and conventional farms.
Table 1. Dominance of weed species (measured by weed cover) between
organic and conventional maize fields in Jaszsag Region, Hungary, 2011
N
u
m
be
r
Weed species
Average
cover in
organic
fields (%)
Rank in
organic
fields
Average
cover in
convention
al fields
(%)
Rank in
conventio
nal fields
1 Amaranthus albus 0.01 18 - NA*
2
Amaranthus
retroflexus
0.84 7 0.09 9
3
Ambrosia
artemisiifolia
5.27 2 - NA*
4
Chenopodium
album
1.20 3 0.49 5
5 Chenopodium 0.02 16 0.34 7
79

Domer et al.
hybridum
6 Cirsium arvense 0.97 5 0.48 6
7
Convolvulus
arvensis
0.71 8 0.65 3
8 Datura stramonium 0.11 11 - NA*
9
Echinochloa crusgalli
13.15 1 1.12 1
10 Fallopia
convolvulus
0.02 15 - NA*
11 Hibiscus trionum 0.96 6 0.62 4
12 Lathyrus tuberosus 0.04 13 - NA*
13 Persicaria
lapathifolia
0.42 9 - NA*
14 Polygonum
aviculare
0.03 14 0.24 8
15 Portulaca oleracea 0.01 18 - NA*
16 Setaria pumila 1.02 4 1.01 2
17 Solanum nigrum 0.01 17 - NA*
18 Sonchus asper 0.05 12 - NA*
19 Xanthium
0.34 10 0.06 10
strumarium
NA*: These species were not present in t le farm.
A significant interaction were found between farms and sampling
times (F = 32.05, /K 0.001). The main effect of farms on weed cover was
significant (F = 134.18, p

Weed composition and diversity of organic and conventional maize fields .
In the first sampling, weed cover of organic fields was higher than of
conventional field with 18.22 and 1.38%, respectively (Fig. 2); mean
difference between them was significant (F=36.56, /?

Domer et al.
50
45
40
3? 35
■ organic field
□ coventional field
1st sampling
2nd sampling
sampling time
3rd sampling
Figure 2. Weed cover of organic and conventional maize fields at three weed
assessment time in Jaszsag region, Hungary, 2011
The main effect of farms on diversity index was significant (F =
12.42, p =0.001), but the main effect of sampling times on diversity index
was not significant (F = 2.63, />=0.078). There was a significant interaction
between farms and sampling times (F= 9.27,/?

Weed composition and diversity of organic and conventional maize fields .
Table 3. Linear model of effect of farm systems and sampling times on
Shannon diversity index
Test of Between-Subjects Effects
Dependent Variable: Shannon’s diversity index
Source
Type III
Sum of
Squares
df
Mean
Square
Corrected 0.816a 5 0.163 8.064 <
Model 10.162 1 10.162 502.364 0.001
Intercept 0.251 1 0.251 12.424 <
Farm 0.107 2 0.053 2.632
Time 0.375 2 0.188 9.271
Farm*Time 1.659 82 0.020
Error 13.026 88
Total 2.474 87
Corrected
Total
a. R Squared = 0.330 (Adjusted R Squared = 0.289)
F
Sig
0.001
0.001
0.078
<
0.001
Figure 3. Shannon diversity indexes of organic and conventional maize fields
at three weed assessment time in Jaszsag region, Hungary, 2011
83

Domer et al.
Conclusions
Sampling time had effect on weed cover but not on diversity index.
Weed covers in organic fields were highest in the second sampling, and
reduced in the third. It can be explained by the weed growth stages which got
maximum cover at the same time of second sampling. By contrast, in
conventional fields, weed germinated later and established highest cover at
the end of growing season. Differences in diversity index between sampling
times were not significant.
There were many differences of presented weed species between
organic fields and conventional fields. The most dominant weed of both
organic and conventional fields was Echinochloa crus-galli. Ambrosia
artemisiifolia ranked as the second cover of organic, but was not present in
conventional ones. Setaria pumila ranked the fourth of organic fields but as
the second in conventional fields. Many weeds such as Ambrosia
artemisiifolia, Persicaria lapathifolia, Datura stramonium, and Lathyrus
tuberosus were recorded in organic fields but were absent from conventional
fields.
Farming systems affected the weed flora in fields. Average total weed
cover and diversity index of organic maize fields were higher than those in
conventional fields. The effect of farms was significant both on weed cover
(F= 134.18, p

Weed composition and diversity of organic and conventional maize fields .
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and conventional winter cereal fields and 15 years ago. 16th IFOAM organic world
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86

Herbologia, Vol. 13, No. 2, 2012
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Herbologia, Vol. 13, No. 2, 2012
Referees of the papers in the Herbologia Vol. 13, No. 2/2012.
Mirha Đikić, Sarajevo, B&H
Drena Gadžo, Sarajevo, B&H
Gabriella Kazinczi, Kaposvar, Hungary
Mira Knežević, Osijek, Croatia
Vaclav Kohout, Prague, Czech Republic
Senka Milanova, Kostinbrod, Bulgaria
Ljiljana Nikolić, Novi Sad, Serbia
Milena Simić, Belgrade, Serbia
Stefan Tyr, Nitra, Slovakia