Printer Friendly

Allelopathic potential of various plant species on Hordeum spontaneum.

Introduction

Weed cause considerable economic losses in crop production and therefore weed management is necessary in agriculture. Chemical methods are commonly used to control weed [10] but, today agriculture has become heavily reliant on the use of synthetic herbicides [23]. This reliance has resulted in many environmental effects such as contamination of ground water resource [21] and development of herbicide resistance weed biotypes, so far more than 290 weed resistant biotypes toward herbicides have been identified [13,31,12]. Management methods that decrease requirements for synthetic herbicides are needed to reduce adverse environmental impacts. One approach is the use of allelochemicals to control weeds [28,1,27].

Allelopathy is a chemical interaction (stimulatory as well as inhibitory effects) between plants (microbes and higher plants) [19,28] later defined allelopthay as direct or indirect effects of one donor plant on a recipient plant. Allelopathy may be used in several ways in weed control. Just as crop plants are bred for disease resistance, crop plants can be bred to be allelopathic to weeds common to specific regions [28,29,14,39]. The most practical and immediate way to use allelopathy in weed control is to use allelopathic cover crops in rotations, or apply residues of allelopathic weeds or crops as mulches [28,2,5]. An equally promising way to use allelopathy in weed control is using extracts of allelopathic plants as herbicides [4,32]. For example cover crops, such as legumes, manage to suppress weeds in corn and increase grain yield [15,43]. In addition, rye as cover crop caused significant reduction of density and biomass of several weed species in corn and soybean [18,20].

Several crops are known to have allelopathic effects on other crops, e.g. sugar beet (Beta vulgaris L.), lupin (Lupinus lutens L.), maize (Zea mays L.), wheat (Triticum aestivum L.), oats (Avena sativa L.) and barley (Hordeum vulgare L.) [28]. The initial step towards the development of allelopathic cultivars in breeding programs is the evaluation of crop germplasm for cultivars that are likely sources of high allelopathic activity. Corresponding screening programs were recently done for e.g. rice [7,6,24,22], wheat [34,39] and oat.

Wheat is the most important crop in Iran and annually sown in more than 6 million hectares and produce around 14.5 million ton grain yield. Wild barley (Hordeum spotaneum) is one of the most important weed in wheat production area in southern Iran. There is no appropriate selective herbicide for controlling this weed. This study was therefore conducted to evaluation the effect of different plant species water extract on wild barley. This information is a prerequisite for the development of biological weed control methods for wheat production.

Material and Methods

Twenty plant species were selected for allelopathic potential on wild barley and wheat.

Plants were grown in pots in a greenhouse. At the beginning of flowering, the plants were harvested, separated into leaves and roots and air-dried. The dried material of each plant was ground in grinder and soaked in distilled water for 24 hours at room temperature (28 [+ or -] 4) at the ratio of 1:20 (1 g plant material per 20 ml water). Each extract was filtered through a Whatman #42 filter paper. The sterilized filtrate was designated as full strength (100%) then used to prepare 25, 50 and 100% concentration by diluting with distilled water. The extract stored at <5 ?C before and during its use in the experiment.

A Whatman #42 filter paper was then placed on the sand surface in into 9-cm diam. petri dishes. 10 mL of the extract was applied into the each petri dishes. Deionized water was used for the control. Fifteen non dormant seed of wild barley were placed, equally spaced, in a circle on the filter paper placed on the surface of each petri dish. Then petri dishes were placed incubated in light at 27[degrees]C temperature for 5-7 days. Germination and root and shoot growth were taken for 10 randomly selected germinating seeds. Germination was defined as root emergence. Root and shoot growth was determined by measuring root and shoot length to the nearest tenth of a millimeter. Effect of water plant extract also was examined on wheat seed germination and growth.

The experiment was conducted using a completely randomized design with four replications. The analysis of variance was conducted using the Genstat software (ver. 12). Means were separated using the LSD test and statistical significance was evaluated at P 0.05.

Results and Discussion

Phytotoxic Effects Of Leaf Extracts On Wild Barley:

Plant leaf extracts effects on wild barley seed germination and root and shoot growth are shown in Table 1. Except sunflower, soybean and cotton, all plant extracts reduced wild barley seed germination significantly in comparison to control. Reduction in seed germination ranged from 7 to 43%. Sugar beet extract showed the highest inhibition against wild barley germination. After sugar beet, cowpea, ramina bean, mung bean, sorghum and safflower show considerable reduction in seed germination. Root growth of wild barley was significantly reduced by most, except six (millet, chickpea, sunflower, corn, oat and soybean), leaf extracts when comprised with control. Reduction of wild barley root length by leaf extracts of different species ranged from 2.5-59.8%. Sugar beet, sorghum and safflower were more phytotoxic against wild oat root growth than other species. Shoot growth of wild barley, also significantly reduced by various plant leaf extract, except millet and chickpea (Table 1). Leaf extract of sugar beet, safflower, red bean, alfalfa and ramina bean showed the highest inhibitory effects on wild barley shoot length. The inhibitory effect of leaf extract from most legumes (i.e. cow pea, mung bean, red bean ramina bean and alfalfa) and broadleaved species were more than cereals.

Phytotoxic Effects of Stem Extracts on Wild Barley:

Leaf water extract from different plants species showed inhibitory effects on germination and root and shoot growth of wild barley (Table 2). All water extract except safflower reduced wild barley germination compared to distilled water control. Ramina bean stem extract showed the highest reduction (40% reduction compared to control) in wild barley seed germination. All extracts showed a significant inhibitory effect on root elongation of wild barley (Table 2). Nine species reduced wild barley root growth more than 30% and five species (ramina bean, sorghum, mung bean, red bean and cow pea) reduced root growth more than 40%. Except sorghum and rice, extract from other cereals were less effective compared to broad leaf species. There is also significant reduction in shoot growth of wild barley by all plants (except safflower) water extract with the highest reduction for sorghum and sunflower. There are different phytotoxic effects in plant leaf and stem. For example chick pea and sunflower stem water extract significantly reduced root growth but leaf extract of these species showed no significant inhibitory effects.

Phytotoxic Effects of Root Extracts on Wild Barley:

The effects of plant root extracts on wild barley seed germination and root and shoot growth are shown in Table 2. Reduction in wild barley seed germination was ranged from 5.4 to 34.6 and significantly reduced by 40% of the plant species extract. Plant root extracts reduce wild barley root growth by 0 to 51.1% and shoot from 6.8 to 48.5%. Extract from sugar beet, alfalfa and cotton reduced root and shoot growth more than 40%. Root extract from cowpea, safflower and chickling pea also, highly reduced wild barley root growth. Rapeseed and soybean were least effective in root and shoot growth inhibition. Root extract generally was less phytotoxic than stem and leaf extract.

Phytotoxic Effects Plant Extracts on Wheat:

Extracts were evaluated for phytotoxicity on wheat germination and root and shoot growth (Table 4). Most of species which reduced wild barley growth also reduced wheat root growth. Mung bean, sugar beet, cowpea and safflower leaf extract causes more than 40% reduction in wheat root growth. Rice and red bean stem extract showed the highest reduction against wheat root growth compared to control. Root extracts of mung bean, sugar beet, chickling pea, alfalfa and sunflower showed the highest inhibitory effect on root growth of wheat.

Although leaf extract of sunflower, chick pea and chickling pea significantly reduced wild barley germination and root and shoot growth, they showed no significant inhibitory effect on wheat root growth. In relation to stem extract species such as ramina bean, mung bean and chick pea which seriously reduced wild barley germination and root growth had no significant effects on wheat root growth. Other stem extracts which had no significant effects on wheat root growth were barley, wheat, rapeseed and cotton. Safflower and sorghum root extract also showed no significant effects on wheat root growth while, significantly reduced wild barley germination and growth.

Comparison of Inhibitory Effect of Different Parts of Plants:

Inhibitory effect of leaf, stem and root extract of different species are shown in Fig 1. There is considerable variation in distribution of allelochemicals in different plant parts. Species likes cowpea, red bean and alfalfa showed high inhibitory effects by leaf, stem and root extracts. Inhibitory effects of these three parts also were similar in barley and oat. Sugar beet showed high inhibitory effects in both leaf and root extracts. In sorghum, mung bean and ramina bean inhibitory of leaf and stem was higher than root extracts. Safflower, cotton and corn stem extract showed lower inhibitory than leaf and root. Root inhibitory effect was low in ramina bean and wheat while leaf inhibitory effect was low in sunflower, chick pea and millet.

Discussion:

Results clearly demonstrated that most of the plant species tested inhibited seed germination and root and shoot growth of wild barley and wheat. In some situation germination responses to different extracts were not significantly different yet root and shoot lengths were significantly affected by extracts (Tables 1, 2 and 3). These means that some extracts targeted root and shoot growth and may have potential for postemergence weed control. In comparison some of the plant extracts evaluated in this study act by inhibiting seed germination (for example, sugar beat, cowpea, rice and ramina bean) and may have potential for preemergence weed control. Extracts from broadleaf plants such as sugar beet and legumes such as alfalfa, red bean, cow pea, ramina bean, mung bean were generally more phytotoxic than those from cereal plants (Fig. 1). Except in this area was sorghum and wheat leaf extracts and rice stem extract. This information has important implications for weed control in cereal-based cropping systems. This implication can be adding to beneficial effects of legume crops in rotation with cereals likes' wheat. In addition allelopathic legume crops can be used as cover crops and their residues can be incorporated or applied as mulch to control weeds. This operation can reduce herbicide and N input (through nitrogen fixation) costs in cereals production. Timing of application should be chosen carefully since some of the crops inhibit wheat growth. [38] reported germination inhibition of some crops from residues and leachates of crimson clover (Trifolium incarnatum) and hairy vetch (Vicia villosa). They also reported that V. villosa residues may suppress weed germination through allelopathy. [2] evaluated the toxic effects of four legumes and showed that the use of velvetbean (Mucuna pruriens) and other legumes as living cover crops or dead mulches could contribute to reduction of weed seed bank in soils and in the improvement of corn production, delaying weed appearance.

In the plant species evaluated, leaf and stem extracts were more effective in reducing seed germination and root and shoot length of wild barley than root extracts (Fig. 1). [8,25,36], Tawaha and [36] and [42] made similar observations on other plant species. However some plants, such as millet, chickling pea, cotton and alfalfa, showed more phytotoxic effects in root than in leaf and stem extracts. Variations in different plant parts extract effects may indicate the presence of different allelochemicals or concentrations of allelochemicals in different plant parts. For example, [22] and [3] reported that sorgoleone, an allelochemical of sorghum, constituted more than 80% of root exudate composition but none was found in immature and mature leaves and stems of sorghum [41]. In contrast, sorghum shoots produce higher amounts of cynogenic glucosides whose phenolic breakdown products inhibit plant growth [9,37,30,40] showed that similar allelochemicals are presented in shoot and root of Australian wheat genotypes, it has been observed that leaf extracts of wheat is the most phytotoxic plant part extracts in both germination and radicle tests [25,11]. Leaf extracts of Artemisia princeps also decreased seedling elongation of receptor plants more than root and stem extracts [16].

Most of the evaluated plant extracts were phytotoxic to both wild barley and wheat seed germination and root and shoot growth. However, wheat was less sensitive to leaf extract of sunflower, chick pea and chickling pea and stem extract of ramina bean, mung bean and chick pea than wild barley. It has been observed that different seed showed different sensitivity to plants extract [26,8,17]. In practice, timing and type of use of these allelopathic plants as cover crop or mulches should be chosen carefully to minimize effects on wheat growth. On other hand, breakdown patterns of allelochemicals of various plant species under field conditions require investigations.

Conclusion:

Most plant species evaluated in the present study, in particular, sugar beet, sunflower, safflower, legume crops such as red bean, ramina bean, chick pea and chickling pea, significantly reduced the germination and root and shoot growth of wild barley and have great potential for management of this weed in wheat production systems. Additional work is required to test the efficacy of residues or extracts from these plants on weed control under field conditions and to isolate and identify allelochemicals involved. This information also may allow the development of biosynthesized herbicides and other biologically based weed control methods in sustainable crop production.

[FIGURE 1 OMITTED]

References

[1.] Bames, J.P., A.R. Putnam and A.J. Aasen, 1987. Isolation and characterization allelochemicals in rye herbage. Phytochem, 26: 1385-1390.

[2.] Caamal-Maldonado, J.A., J.J. Jimenez-Osorina, A.T. Barragan and A.L. Anaya, 2001. The use of allelopathic legume cover and mulch species foe weed control in cropping systems. Agron. J. 93: 27-36.

[3.] Czarnota, M.A., A.M. Rimando and L.A. Weston, 2003. Evaluation of root exudates of seven sorghum accessions. J. Chem. Ecol., 29: 2073-083.

[4.] Dayan, F.E., 2002. Natural pesticides. P: 521525. In D. Pimentel (ed.) Encylopedia of pest management. Marcel Dekker, Inc., New York.

[5.] Dhima, K.V., I.B. Vasilakoglu, I.G. Elefterohorinos and A.S. Lightourgidis, 2006. Allelopathic potential in cereal crops. Mulches on grass weed suppression and sugar beet development. Crop Sci., 46: 1682-1691.

[6.] Dilday, R.H., W.G. Yan, K.A.K. Moldenhauer,

K.A. Gravois, 1998. Allelopathic activity in rice for controlling major aquatic weeds. In Allelopathy in Rice, pp: 7-26. Ed. M Olofsdotter. Los Banos, Philippines: IRRI Publishing.

[7.] Dilday, R.H., J. Lin and W. Yan, 1994. Identification of allelopathy in the USDA-ARS rice germplasm collection. Aust. J. Exp. Agric., 34: 901-910.

[8.] Ebana, K., W. Yan, R.H. Dilday, H. Namai and K. Okuno, 2001. Variation in the allelopathic effect of rice with water soluble extracts. Agron J., 93: 12-16.

[9.] Einheling, F.A. and J.A. Rasmussen, 1989. Prior cropping with grain sorghum inhibits weeds. J. Chem. Ecol., 15: 951-960.

[10.] Giudence, V.L., 1981. Present status of citrus weed control in Italy. Proc. INt. Soc. Citrus. 2: 458-487.

[11.] Guenzi, W.D., T.M. McCalla and F.A. Norstad. 1967. Presence and persistence of phytotoxic substances in wheat, oats, corn and sorghum residues. Agron. J., 59: 163-165.

[12.] Heap, I., 2005. International survey of herbicide resistant weeds. Herbicide Resistance Action Committee, North American Herbicide Resistance Action Committee and Weed ci. Soc. Am. Internet: http://www.weedscience.org.

[13.] Holt, J.S. and H.N. LeBaron, 1990. Significance and distribution of herbicides resistance. Weed Techol, 4: 141-149.

[14.] Jensen, L.B., B. Courtois, L. Shen, Z. Li, M. Olofsdotter and R.P. Mauleon, 2001. Locating genes controlling allelopathic effects against barnyardgrass in upland rice. Agron. J., 93: 21-26.

[15.] Johnson, G.A., M.S. DeFelice and Z.R. Helsel, 1993. Cover crop management and weed control in corn (Zea mays). Weed Technol., 7: 425-430.

[16.] Kil, B.S. and K.W. Yun, 1992. Allelopathic effects of water extracts of Artemisia princeps var. orientalis on selected plant species. J. Chem. Ecol, 18: 39-51.

[17.] Koloren, O., 2007. Allelopathic effects of Medicago sativa L. and Vicia cracca L. leaf and root extract on weeds. Pak. J. Biol. Sci., 10: 1639-1642.

[18.] Liebl, R., F.W. Simmons, L.M. Wax and E.W. Stoller, 1992. Effect of rye (Secale cereale) mulch on weed control and soil moisture in soybean (Glycine max). Weed Technol., 6: 838-846.

[19.] Molisch, H., 1937. Der Einfluss einer Pflanze auf die andere-Allelopathie. Jena, Germany: Fischer (Jena).

[20.] Moore, M.J., T.J. Gillespie and C.J. Swanton. 1994. Effect of cover crop mulches on weed emergence, weed biomass and soybean (Glycine max) development. Weed Technol., 8: 512-518.

[21.] National Research Council, 1993. Soil and Water Quality: An Agenda for Agriculture. National Academy Press, Washington, DC.

[22.] Nimbal, C.I., J.F. Pedersen, C.N. Yerkes, L.A. Weston and S.C. Weller, 1996. Phytotoxicity and distribution of sorgoleone in grain sorghum germplasm. J. Agric. Food Chem., 44: 13431347.

[23.] Ohno, T., K. Doolan, L.M. Zibilske, M. Liebman, E.R. Gallandt and C. Berube, 2000. Phytotoxic effects of red clover amended soils on wild mustard seedling growth. Agric. Ecosyst. Environ, 78: 187-192.

[24.] Olofsdotter, M. and D. Navarez, 1996. Allelopathic rice in Echinochloa crus-galli control. p. 1175-1182. In H. Brown et al. (ed.) Proc. of the 2nd Int. Weed Control Congress, Copenhagen, Denmark.

[25.] Oueslati, O., 2003. Allelopathy in two durum wheat (Triticum durum L.) varieties. Agric. Ecosys. Environ. 96: 161-163.

[26.] Perez F.J., 1990. Allelopathic effect of hydroxamic acids from cereals on Avena sativa and A. fatua. Phytochem. 29: 773-776.

[27.] Putnam, A.R., 1988. Allelochemical from plants as herbicides. Weed Technol., 2: 510-518.

[28.] Rice E.L., 1984. Allelopathy. 2nd Edn. Orlando, Florida, USA: Academic Press.

[29.] Rice, E.L., 1995. Biological control of weeds and plant diseases: advances in applied allelopathy. University of Oklahoma Press.

[30.] Se'ne, M., T. Dore and C. Gallet, 2001. Relationship between biomass and phenolic production in grain sorghum grown under different conditions. Agron. J., 93: 49-54.

[31.] Shaner, D.L., 1997. Herbicide resistance in North America: History, circumstance of development and current situation. In: Weed and Crop Resistance to Herbicides, De Prado, R. Jorrin J. and Carsia Torres L. Eds. Kulwer Academic Publishers, Dordrecht, The Netherlands.

[32.] Singh, H.P., D.R. Batish and R.K. Kohli, 2003. Allelopathic interactions and allelochemicals: New possibilities for sustainable weed management. Critical Reviews in Plant Sciences, 22: 239-311.

[33.] Singh, H.P., D.R. Batish, S. Kaur, N. Setia and R.K. Kohli, 2005. Effects of 2-benzoxazolinone on the germination, early growth and morphogenetic response of mung bean (Phaseolus aureus). Ann. ppl. Biol., 147: 267-274.

[34.] Spruell, J.A., 1984. Allelopathic potential of wheat accessions. Dissertation Abstracts International, B Sciences and Engineering. Ph.D. Thesis, University of Oklahoma, USA 45: 1102B.

[35.] Tawaha, A.M. and M.A. Turk, 2003. Allelopathic effects of black mustard (Brassica nigra) on the germination and growth of wild barley (Hordeum spontaneum). J. Agron. Crop Sci., 189: 298-303.

[36.] Turk, M.A., M.K. Shatnawi and A.M. Tawaha, 2003. Inhibitory effects of aqueous extracts of black mustard on germination and growth of alfalfa. Weed Biol. Manag, 3: 37-40.

[37.] Weston, L.A., R. Harmon and S. Mueller, 1989. Allelopathic potential of sorghum-sudangrass hybrid (sudex). J. Chem. Ecol., 15: 1855-865.

[38.] White, R.H., A.D. Worsham and U. Blum, 1989. Allelopathic potential of legume debris and equeous extracts. Weed Sci., 676-79.

[39.] Wu, H., J. Pratley, D. Lemerle and T. Haig, 2000a. Evaluation of seedling allelopathy in 453 wheat (Triticum aestivum) accessions by Equal-Compartment-Agar-Method. Aust. J. Agric. Res., 51: 937-944.

[40.] Wu, H., T. Haig, J. Pratley, D. Lemerle and M. An, 2000b. Distribution and exudation of allelochemicals in wheat (Triticum aestivum L.). J. Chem. Ecol., 26: 2141-2154.

[41.] Yang, W., B.E. Scheffler and L.A. Weston, 2004. SOR1, a gene associated with bioherbicide production in sorghum root hairs. J. Expl. Bot., 55: 2251-2259.

[42.] Yarnia, M., M.B. Khorshidi Benam and E. Farjadzadeh Memari Tabrizi, 2009. Allelopathic effects of sorghum extracts on Amaranthus retroflexus seed germination and growth. J. Food Agric. Environ, 7: 7790-774.

[43.] Yenish, J.P., A.D. Worsham and A.C. York, 1996. Cover crops for herbicide replacement in no-tillage corn (Zea mays). Weed Technol., 10: 815-821.

Hamid Reza Miri

Assistant professor, Islamic Azad University, Arsanjan Branch Arsanjan, Fars, Iran.

Hamid Reza Miri: Allelopathic Potential of Various Plant Species on Hordeum Spontaneum

Corresponding Author

Hamid Reza Miri, Assistant professor, Islamic Azad University, Arsanjan Branch Arsanjan, Fars, Iran.

Tel: +989171022603; Fax: +987297622483; Email: hrmiri@iaua.ac.ir
Table 1: Phytotoxic effects of plant leaf extracts
on wild barley germination and root and shoot
growth.

 Root

 Germination Length Reduction
Plant Scientific name (%) (mm) (%)

Sugar beet Beta vulgaris 52.5 7.7 59.8
Sorghum Sorghum bicolor 65.8 8.7 54.8
 Carthamus
Safflower tinctorius 68.3 8.7 54.8
Cowpea Vigna unguiculata 60.8 9.8 49.2
Mung bean Vigna radiate 65.0 9.9 48.6
Red bean Phaseolus sp. 70.0 10.6 44.9
Ramina bean Phaseolus sp. 63.3 11.3 41.4
Wheat Triticum aestivum 70.0 11.4 40.6
Alfalfa Medicago sativa 71.4 12.0 37.9
Cotton Gossypium hirsutum 86.7 12.2 36.8
Rice Oryza sativa 75.0 14.8 22.9
Chickling pea Lathyrus hirsutus 74.2 15.0 22.3
Barley Hordeum vulgare 75.0 15.3 20.6
Rapeseed Brassica napus 76.7 15.3 20.6
Soybean Glycine max 85.8 16.0 16.7
Oat Avena sativa 80.0 16.2 15.9
Corn Zea mays 78.3 16.6 13.7
Sunflower Helianthus annuus 85.8 18.1 5.9
Chickpea Cicer arietinum 75.8 18.5 3.9
Millet Setaria italica 80.0 18.8 2.5
Control 93.5 19.3 0.0
LSD 8.4 3.2

 Shoot

 Length Reduction
Plant Scientific name (mm) (%)

Sugar beet Beta vulgaris 15.0 62.7
Sorghum Sorghum bicolor 25.1 37.3
 Carthamus
Safflower tinctorius 19.0 52.6
Cowpea Vigna unguiculata 25.7 35.8
Mung bean Vigna radiate 25.3 36.8
Red bean Phaseolus sp. 18.1 54.8
Ramina bean Phaseolus sp. 22.3 44.4
Wheat Triticum aestivum 28.7 28.4
Alfalfa Medicago sativa 20.8 48.1
Cotton Gossypium hirsutum 33.4 16.7
Rice Oryza sativa 33.6 16.2
Chickling pea Lathyrus hirsutus 31.9 20.5
Barley Hordeum vulgare 35.9 10.6
Rapeseed Brassica napus 32.4 19.3
Soybean Glycine max 27.1 32.5
Oat Avena sativa 31.2 22.2
Corn Zea mays 38.5 3.9
Sunflower Helianthus annuus 35.3 12.0
Chickpea Cicer arietinum 38.0 5.1
Millet Setaria italica 40.3 -0.4
Control 40.1 0.0
LSD 3.5

Table 2: Phytotoxic effects of plant stem extracts
on wild barley germination and root and shoot
growth.

 Root Shoot

 Germination Length Reduction Length Reduction
Plant (%) (mm) (%) (mm) (%)

Ramina bean 50.8 14.2 49.6 27.4 47.8
Sorghum 60.0 14.6 48.2 23.0 56.1
Mung bean 64.2 16.9 40.2 36.6 30.4
Red bean 59.2 16.9 40.1 30.0 42.9

Cowpea 62.5 16.9 40.0 32.9 37.4
Rice 58.3 17.7 37.3 27.9 46.8
Chickpea 65.8 18.5 34.5 38.8 26.1
Alfalfa 64.2 19.2 31.8 31.7 39.7
Chickling pea 71.7 19.5 30.8 41.5 21.0
Sunflower 70.8 20.9 26.0 25.0 52.4
Soybean 70.0 21.3 24.4 34.5 34.4
Rapeseed 70.8 22.1 21.8 38.7 26.3
Oat 75.0 23.2 17.8 34.7 33.9
Barley 67.5 23.3 17.5 29.4 44.1
Cotton 74.2 23.9 15.4 44.6 15.0
Wheat 70.0 24.4 13.4 33.7 35.9
Safflower 84.2 26.9 4.6 50.3 4.3
Corn 63.3 27.3 3.2 38.9 25.9
Millet 76.7 27.4 2.8 42.0 20.0
Control 84.7 28.2 0.0 52.5 0.0
LSD 7.3 2.7 3.2

Table 3: Phytotoxic effects of plant root extracts
on wild barley germination and root and shoot
growth.

 Root Shoot
Plant Germination Length Reduction Length Reduction
 (%) (mm) (%) (mm) (%)

Sugar beet 63.3 13.2 51.1 23.1 48.5
Alfalfa 58.8 15.0 44.2 26.2 41.5
Red bean 72.9 15.6 42.0 26.0 41.9
Cotton 80.4 15.9 40.8 27.1 39.5
Cowpea 76.7 16.6 38.4 30.4 32.1
Safflower 72.9 16.6 38.2 26.1 41.7
Chickling pea 78.3 16.6 38.2 34.1 24.0
Sorghum 70.8 19.7 26.9 32.1 28.3
Mung bean 77.1 20.1 25.3 35.5 20.9
Oat 77.1 21.3 20.8 36.5 18.7
Millet 76.7 21.9 18.7 38.8 13.5
Barley 71.7 21.9 18.6 36.2 19.2
Sunflower 78.3 22.2 17.4 35.6 20.6
Chickpea 77.1 23.4 12.9 40.0 10.7
Rice 80.4 23.9 11.3 37.8 15.6
Corn 80.0 23.9 11.2 37.5 16.4
Wheat 72.1 25.3 5.8 38.9 13.2
Ramina bean 72.8 25.9 3.6 38.8 13.5
Rapeseed 85.0 28.4 -1.6 41.8 6.8
Soybean 81.7 28.2 -1.1 39.1 12.9
Control 89.9 27.9 0.0 44.8 0.0
LSD 13.4 2.4 3.5

Table 4: Phytotoxic effects of plant leaf, stem
and root extracts on wheat root growth.

 Leaf Stem

 Length Reduction Length Reduction
Plant (mm) (%) (mm) (%)

Red bean 17.2 37.6 15.0 47.6
Sugar beet 14.7 46.5 -- --
Chickling pea 24.3 11.6 18.7 34.8
Alfalfa 19.9 27.7 26.5 7.8
Sunflower 28.6 -4.0 20.9 27.2
cotton 20.5 25.5 27.2 5.4
Mung bean 14.6 46.8 27.0 6.0
Chickpea 25.8 6.3 27.4 4.5
Cowpea 15.9 42.3 22.9 20.1
Millet 24.4 11.3 20.2 29.6
Romana bean 19.9 27.6 27.9 2.8
Corn 27.6 -0.3 23.5 18.2
Soybean 26.8 2.7 30.5 -2.8
Safflower 16.2 40.9 18.9 34.1
Sorghum 19.8 28.1 22.4 22.1
Rapeseed 20.7 24.8 26.8 6.8
Rice 22.4 18.5 13.1 54.3
Oat 25.5 7.3 24.5 14.7
Barley 20.5 25.3 28.0 2.4
Wheat 19.6 28.9 26.9 6.4
control 27.5 0.0 28.7 0.0
LSD 4.1 3.7

 Root

 Length Reduction
Plant (mm) (%)

Red bean 13.9 51.6
Sugar beet 15.4 46.6
Chickling pea 15.5 46.1
Alfalfa 16.2 43.6
Sunflower 16.8 41.5
cotton 18.4 36.1
Mung bean 19.4 32.7
Chickpea 19.5 32.2
Cowpea 20.8 27.8
Millet 21.2 26.5
Romana bean 22.6 21.4
Corn 23.2 19.3
Soybean 26.2 9.0
Safflower 26.6 7.5
Sorghum 26.9 6.5
Rapeseed 28.1 2.5
Rice 28.2 1.8
Oat 27.8 3.3
Barley 28.3 1.5
Wheat 28.5 1.0
control 28.8 0.0
LSD 3.3
COPYRIGHT 2011 American-Eurasian Network for Scientific Information
No portion of this article can be reproduced without the express written permission from the copyright holder.
Copyright 2011 Gale, Cengage Learning. All rights reserved.

Article Details
Printer friendly Cite/link Email Feedback
Title Annotation:Original Article
Author:Miri, Hamid Reza
Publication:Advances in Environmental Biology
Article Type:Report
Geographic Code:7IRAN
Date:Nov 1, 2011
Words:4758
Previous Article:Effect of osmopriming on harvested seed vigor of Maize (Zea Mays L.).
Next Article:Inhibitory effects of sunflower root and leaf extracts on germination and early seedling growth of amaranth and purple nutsedge.
Topics:

Terms of use | Privacy policy | Copyright © 2018 Farlex, Inc. | Feedback | For webmasters