Response of winter wheat (Triticum aestivum L.) and weeds to tank mixtures of 2,4-D plus MCPA with clodinafop propargyl

Field and greenhouse experiments were conducted in 2004 and 2005 to study weed control and the response of winter wheat to tank mixtures of 2,4-D plus MCPA with clodinafop propargyl. The field experiments were conducted at Yazd and Oroumieh, Iran, with factorial combinations of 2,4-D plus MCPA at 0, 975, and 1300 g ai ha⁻¹ and with clodinafop propargyl at 0, 64, 80, 96, and 112 g ai ha⁻¹ in four replications. The greenhouse experiments further evaluated the effect of these tank mixtures on weed control, where each herbicide mixture was considered as one treatment and the experiment was established in a randomized complete block design with four replications. In the field experiments, the herbicides were applied at wheat tillering, while in the greenhouse experiments they were applied at the beginning of the tillering stage and at the four-leaf stage of the grass and broadleaf weeds, respectively. The results indicated antagonistic effects between 2,4-D plus MCPA and clodinafop propargyl. The best tank mixture with regard to weed control efficacy was 2,4-D plus MCPA at 975 g ai ha⁻¹ with clodinafop propargyl at 96 g ai ha⁻¹. The wheat grain yield was also increased by the tank mixture of clodinafop propargyl with 2,4-D plus MCPA. Generally, to inhibit clodinafop propargyl efficacy reduction due to tank-mixing with 2,4-D plus MCPA, it is recommended that the application dose of 64 g ai ha⁻¹ should be increased to 96 g ai ha⁻¹.     

Responses of otebo bean (Phaseolus vulgaris L.) to postemergence herbicides

Ontario otebo bean growers have few herbicide options available for weed management. Six field trials were conducted in Ontario, Canada, over a 2 year period (2003 and 2004) to evaluate the tolerance of otebo bean to the postemergence (POST) application of bentazon at 1080 and 2160 g ai ha⁻¹, fomesafen at 240 and 480 g ai ha⁻¹, sethoxydim at 500 and 1000 g ai ha⁻¹, quizalofop-p-ethyl at 72 and 144 g ai ha⁻¹, imazamox plus fomesafen at 25 + 200 and 50 + 400 g ai ha⁻¹, and imazamox plus bentazon at 25 + 600 and 50 + 1200 g ai ha⁻¹. All treatments, including the untreated control, were maintained weed-free during the growing season. The POST application of bentazon, imazamox plus fomesafen, and imazamox plus bentazon caused as much as 9% visual injury and reduced the plant height ≤ 12%, reduced the shoot dry weight ≤ 32%, and delayed maturity but had no adverse effect on the yield of otebo bean. Fomesafen, sethoxydim, and quizalofop-p-ethyl applied POST caused as much as 8% visual injury but this was transient and had no adverse effect on the plant height, shoot dry weight, seed moisture content, and yield of otebo bean, except for quizalofop-p-ethyl, which reduced the shoot dry weight as much as 18%. Based on these results, bentazon, fomesafen, sethoxydim, quizalofop-p-ethyl, imazamox plus fomesafen, and imazamox plus bentazon applied POST have an adequate margin of crop safety for weed management in otebo bean production in Ontario. However, care must be taken to avoid spray overlaps to prevent injury from bentazon, imazamox plus fomesafen, and imazamox plus bentazon.     

Reduced rates of tank mixtures for red sprangletop (Leptochloa chinensis [L.] Nees) and greater club-rush (Scirpus grossus [L.] f.) control in rice

A study on the efficacy of tank-mix combinations on the growth of Leptochloa chinensis (L.) Nees and Scirpus grossus (L.) f. at the 3–4-leaf stage was conducted under glasshouse conditions. Sethoxydim plus cyhalofop-butyl at 8 + 25, 16 + 25, 32 + 25, 32 + 12.5, and 32 + 6.25 g ai ha⁻¹ provided good control of L. chinensis , ranging from 89–95%. However, a comparison of the costs of herbicide mixtures revealed that sethoxydim at 32 g ai ha⁻¹ plus cyhalofop-butyl at 6.25 g ai ha⁻¹ were the most cost-effective among the combinations. For Scirpus grossus , bensulfuron plus 2,4-D dimethylamine at 2.5 + 18, 5.0 + 18, 1.25 + 36, 2.5 + 36, and 5.0 + 36 g ai ha⁻¹ gave good control that ranged from 88–93%. Tank-mixing bensulfuron with 2,4-D at 1.25 + 36 g ai ha⁻¹ was, however, the most cost-effective mixture compared to the other mixtures. None of the tank mixtures tested in this study caused injury to the rice seedlings. However, further field studies need to be undertaken to verify these findings.     

Proper adjuvant selection to enhance the activity of triclopyr combined with metsulfuron on the control of Hedyotis verticillata

A study was conducted to evaluate the combined activity of a tank mixture of triclopyr plus metsulfuron with non-ionic surfactant (NIS), crop oil concentrate (COC), and organosilicon (OS) adjuvants on the control of Hedyotis verticillata under glasshouse and field conditions. The results of both the glasshouse and field experiments showed that 160 g ai ha⁻¹ triclopyr plus 0.2 g ai ha⁻¹ metsulfuron and 320 g ai ha⁻¹ triclopyr plus 0.4 g ai ha⁻¹ metsulfuron, with the addition of 0.25% NIS, 0.05% COC, or 0.05% OS, were effective in controlling H. verticillata . A comparison of the cost revealed that the most cost-effective combination for controlling H. verticillata is 160 g ai ha⁻¹ triclopyr plus 0.2 g ai ha⁻¹ metsulfuron combined with 0.25% NIS.     

Control of weed barley species in winter wheat with sulfosulfuron at different rates and times of application

Field experiments were conducted at five locations in the major wheat production regions of Iran to evaluate the efficacy of sulfosulfuron in controlling weed barley species (including Hordeum spontaneum , Hordeum murinum , Hordeum distichon , and Hordeum vulgare ) in the 2004–2005 and 2005–2006 growing seasons. Sulfosulfuron was applied either postemergence (POST) or preplant-incorporated (PPI) at 0, 20.25, 30.75, 40.5, 51.0, 60.75 or 71.25 g ai ha⁻¹ to plots arranged in a randomized complete block design with four replications. Sulfosulfuron at the recommended rate (20.25 g ai ha⁻¹) failed to provide acceptable control of the weed barley species. However, the level of control increased with the application rate, particularly at rates >51.0 g ai ha⁻¹. Generally, PPI-applied sulfosulfuron resulted in markedly greater control levels than those of a POST application and complete control of H. murinum and H. vulgare was achieved with PPI-applied sulfosulfuron at all rates >20.25 and 30.75 g ai ha⁻¹, respectively. In most cases, the wheat yield increased with the application rate without any crop injury. The highest yield increase (186%) was obtained with a PPI application of 71.25 g ai ha⁻¹.     

Response of black, cranberry, kidney, and white bean to linuron

Dry bean producers in Ontario, Canada, have few herbicide options available for annual broad-leaved weed management and there is little information on the tolerance of dry bean to linuron. The tolerance of black, cranberry, kidney, and white bean to the pre-emergence (PRE) application of linuron at the rates of 0, 500, 1000, 1500, 2000, and 2500 g ai ha⁻¹ was evaluated in field studies conducted in 2005 and 2006 at Exeter and in 2006 at Ridgetown, Ontario. The four market classes differed in their response to linuron. Cranberry and kidney bean were more tolerant to the PRE application of linuron than black and white bean. Linuron applied PRE caused as much as 12% injury in cranberry and kidney bean, 47% injury in black bean, and 56% injury in white bean. Linuron applied PRE at 500–2500 g ai ha⁻¹ had no effect on the height of cranberry and kidney bean but decreased the height by 7, 8, and 15% in black bean and by 10, 13, and 23% in white bean at 1500, 2000, and 2500 g ai ha⁻¹, respectively. Linuron applied PRE at the rates evaluated did not cause any adverse affect on the yield of cranberry, kidney, and white bean but black bean yield was reduced by 16% at 2500 g ai ha⁻¹. Based on these results, there is not an adequate margin of crop safety for the PRE application of linuron in black and white bean at rates >1000 g ai ha⁻¹. However, there is a potential for the use of linuron PRE for weed management in cranberry and kidney bean at the rates evaluated.     

White bean (Phaseolus vulgaris) tolerance to preplant-incorporated herbicides

There is a limited number of registered herbicides in white beans. Field trials were conducted at two Ontario, Canada, locations (Exeter and Ridgetown) in 2001 and 2002 to evaluate tolerance of two white bean cultivars, AC Compass and OAC Thunder, to preplant-incorporated applications of S -metolachlor plus imazethapyr (1600 + 75 and 3200 + 150 g ai ha⁻¹, respectively), flumetsulam plus S -metolachlor ( premixed at 1443 and 2886 g ai ha⁻¹) and cloransulam-methyl (35 and 70 g ai ha⁻¹). There were no differences between the two cultivars in their responses to the herbicide treatments. S -metolachlor plus imazethapyr caused as much as 5% visual crop injury and decreased plant height up to 20%, shoot dry weight up to 39% and yield as much as 21%. Flumetsulam plus S -metolachlor caused as much as 7% visual crop injury and reduced plant height by up to 25%, shoot dry weight by up to 46% and yield as much as 24%. Cloransulam-methyl caused as much as 10% visual crop injury and decreased plant height up to 35%, shoot dry weight up to 55% and yield as much as 44%. There were no differences in seed moisture content among any of the herbicide treatments. This research suggests that the margin of safety of white bean is inadequate to support the preplant-incorporated registration of S -metolachlor plus imazethapyr, flumetsulam plus S -metolachlor and cloransulam-methyl in Ontario.     

Synthesis and herbicidal activity of new 3-(3-bromothiophen-2-yl)-5-(2,6-difluorobenzyl)oxymethyl-5-methyl-4,5-dihydroisoxazole as a paddy field herbicide

A new compound 3-(3-bromothiophen-2-yl)-5-(2,6-difluorobenzyl)oxymethyl-5-methyl-4,5-dihydroisoxazole was synthesized and the herbicidal activity was assessed under glasshouse and flooded paddy field conditions. This compound demonstrated good rice selectivity and potent herbicidal activity against annual weeds at 125 g ai ha⁻¹ under greenhouse conditions. Soil application of this compound showed the complete control of barnyardgrass to the 4th leaf stage at 250 g ai ha⁻¹. Field trials indicated that this compound, combined with pyrazosulfuron-ethyl, controlled annual and perennial weeds rapidly with good tolerance by transplanted rice seedlings from postemergence and soil application. This compound showed a low mammalian and environmental toxicity in various toxicological tests.     

Tolerance of black, cranberry, kidney, and white bean to cloransulam-methyl

The level of tolerance of various market classes of dry bean to cloransulam-methyl is not known. Three field studies were conducted in Ontario, Canada during 2007 and 2008 to determine the level of tolerance of black, cranberry, kidney, and white bean to the pre-emergence (PRE) and postemergence (POST) application of cloransulam-methyl at 17.5, 35, and 70 g ai ha⁻¹. Cloransulam-methyl applied at 17.5, 35, and 70 g ha⁻¹ caused between 13 and 23% injury in black, cranberry, kidney, and white bean, respectively. Cloransulam-methyl applied at 17.5, 35, and 70 g ha⁻¹ reduced the shoot dry weight by between 16 and 28% compared to the untreated control. Cloransulam-methyl applied PRE reduced the height of black bean by 27% and the height of cranberry bean by 25% at 70 g ha⁻¹ and reduced the height of white bean by 19% at 35 g ha⁻¹ and by 37% at 70 g ha⁻¹. Cloransulam-methyl applied PRE reduced the yield of black bean by 29% at 35 g ha⁻¹ and by 43% at 70 g ha⁻¹, reduced the yield of cranberry bean by 43% at 70 g ha⁻¹, and reduced the yield of white bean by 36% at 35 g ha⁻¹ and by 54% at 70 g ha⁻¹. Based on these results, there is not an adequate margin of crop safety for the PRE and POST application of cloransulam-methyl in black, cranberry, kidney, and white bean at the rates evaluated.     

Effect of amitrole and 2,4-D applied preplant and pre-emergence in soybean (Glycine max)

There is limited information on the effect of amitrole and 2,4-D ester applied preplant and pre-emergence in soybean (G lycine max L.) in Ontario, Canada. Six field trials were conducted over a 2 year period (2004 to 2005) at three Ontario locations to evaluate the response of soybean to amitrole or 2,4-D ester applied at 14 days preplant (DPP), 7 DPP, 1 day after planting (DAP), and 7 DAP. The application of amitrole resulted in as much as 5.8, 3.9, 1.7, and 1% visible crop injury in soybean at 7, 14, 28, and 56 days after emergence (DAE), respectively. There was no visible injury in soybean with any amitrole treatment at 56 DAE, except for amitrole applied at 7 DAP, which caused 1% visible injury in soybean at 2310 g ha⁻¹. The application of the 2,4-D ester caused ≤8.3, 9.7, 4.6, and 1.3% visible injury in soybean at 7, 14, 28, and 56 DAE, respectively. The visible injury decreased over time. There was no visible injury in soybean with any of the 2,4-D ester treatments at 56 DAE, except for the 2,4-D ester treatment applied at 7 DAP, which caused 1% visible injury at 1155 g ha⁻¹ and 1.3% visible injury at 2310 g ha⁻¹. Soybean generally responded similarly to amitrole and 2,4-D ester when applied at 14 and 7 DPP; however, soybean was more tolerant to amitrole compared to 2,4-D ester when applied at 1 or 7 DAP. The application of amitrole and 2,4-D ester resulted in no biomass or yield reduction in soybean compared to the weed-free, untreated control at all doses and application timings evaluated. Soybean is tolerant to the preplant and pre-emergence application of amitrole or 2,4-D ester at the doses evaluated.     

Optimizing the performance of diclofop-methyl, cycloxydim, and clodinafop-propargyl on littleseed canarygrass (Phalaris minor) and wild oat (Avena ludoviciana) control with adjuvants

Optimizing the herbicide dose by the addition of adjuvants is an acceptable way to reduce the risk of side-effects from herbicides. Therefore, to detect a suitable adjuvant for diclofop-methyl, cycloxydim, and clodinafop-propargyl against littleseed canarygrass ( Phalaris minor ) and wild oat ( Avena ludoviciana ), six dose–response experiments were conducted. The treatments consisted of diclofop-methyl at 0, 112, 225, 450, 675, and 900 g ai ha⁻¹, cycloxydim at 0, 15, 30, 60, 90, and 120 g ai ha⁻¹, and clodinafop-propargyl at 0, 8, 16, 32, 48, and 64 g ai ha⁻¹ with and without the adjuvants of Frigate, olive oil, and castor oil at 0.2% (v/v) in order to control both littleseed canarygrass and wild oat. Tested herbicides performance was enhanced by all adjuvants against littleseed canarygrass and wild oat. The addition of Frigate and the vegetable oils had the lowest and the highest effect on the performance of all of the herbicides on both littleseed canarygrass and wild oat, respectively, which confirms the solubilizing nature of the cuticular waxes by vegetable oils. A comparison between the two vegetable oils revealed that olive oil exerted a greater control of littleseed canarygrass than did the castor oil. In contrast, castor oil exerted a greater control of wild oat than did the olive oil, which can be related to differences in the leaf surface micromorphology of the weeds.     

Biological activity of pyribenzoxim in winter wheat and associated weeds

Pot and field tests were conducted to evaluate the efficacy of pyribenzoxim for winter weeds in wheat. In the pot tests, pyribenzoxim, at 50 g ha⁻¹, controlled certain biotypes of blackgrass, including a fenoxaprop-P-ethyl-resistant biotype (the "Notts" biotype). A chlorotoluron-resistant blackgrass (the "Peldon" biotype) was not controlled. Cleaver, at the three-to-four-leaf stage, was completely controlled by pyribenzoxim at 30 g ha⁻¹. In the field, the application in December gave good control of common chickweed, but did not control other weeds. No damage to wheat was observed with this rate of pyribenzoxim in December. The application in March gave complete control of blackgrass , hairy chess, and soft brome at 70 g ha⁻¹, and cleaver at 140 g ha⁻¹. The partial control of corn poppy and field violet was achieved. The March application scorched the wheat at 50–70 g ha⁻¹, with prolonged stunting at 100–140 g ha⁻¹. In conclusion, it was shown that pyribenzoxim had potential as a wheat herbicide, but needed further fine-tuning to find an optimum dosage.     

Comparison of different weed management systems and their effects on yield of coconut plantations in Sri Lanka

The influence of five different weed management systems on nut yield of coconut were evaluated to determine an economical and effective method of controlling weeds in coconut plantations in the low country, dry zone in Sri Lanka. Treatments imposed included slashing and mulching around the palms with slash (T1), slashing and removing the slash (T2), application of glyphosate (N-(phosphonomethyl)-glycine) alone at 1.44 kg ai ha⁻¹ (T3), application of glyphosate alone at 2.88 kg ai ha⁻¹ (T4) and cover cropping with Pueraria phaseoloides (T5). All treatments were applied twice a year, except for the cover cropping treatment, T5. Based on a reduction in weed biomass, treatments T3, T4 and T5 were found to be significantly effective over other treatments. Coconut yield was increased significantly ( P  < 0.05) in glyphosate-applied plots at both tested rates. Control of weeds with the lower concentration of glyphosate (1.44 kg ai ha⁻¹) resulted in a 25% increase in nut yield over the uncontrolled weed plots. At this rate, it was found to be the most effective and economical method of controlling weeds in coconut plantations. Cover cropping with Pueraria phaseoloides was effective in controlling weeds in the long-term, but was not economical compared with the glyphosate application.     

Enhanced effect of thiobencarb on bispyribac-sodium control of Echinochloa phyllopogon (Stapf ) Koss. in California rice (Oryza sativa L.)

Bispyribac-sodium {sodium 2,6-bis[(4,6-dimethoxy-2-pyrimidinyl)oxy] benzoate} has recently been introduced to California where it effectively controls Echinochloa spp. in rice ( Oryza sativa L.). However, biotypes of early watergrass ( Echinochloa oryzoides (Ard.) Fritsch) and late watergrass ( E. phyllopogon (Stapf ) Koss.) have evolved resistance to this herbicide. In 2001 and 2002, greenhouse and field experiments evaluated interactions between thiobencarb { S -[(4-chlorophenyl) methyl] diethylcarbamothioate} and bispyribac-sodium on resistant (R) and susceptible (S) late watergrass in California rice. Synergism was assessed using Colby's test and regression analysis. In the greenhouse, thiobencarb at 4480 and 5333 g ai ha⁻¹ synergistically reduced bispyribac-sodium GR₅₀ values on the R and S biotypes by 50–70% without increasing toxicity to rice. Synergism was also observed on S late watergrass in the field when 10 g ai ha⁻¹ bispyribac-sodium was mixed with 1120–2240 g ai ha⁻¹ thiobencarb. These effects could be related to interactions between thiocarbamates and enzymes in Phase I reactions of herbicide metabolism. This synergism results in better control at lower rates allowing a reduction in weed control costs, the herbicide load on the environment and a lower selection pressure towards resistant weed biotypes.     

Less hazardous alternative herbicides to control weeds in immature oil palm

In 2002, the Malaysian government had banned the use of the hazardous herbicide, paraquat. Most growers perceive that paraquat is the most effective herbicide and provides the fastest mode of action to control weeds. An experiment was conducted at MAB Agriculture-Horticulture, Sepang, Selangor, Malaysia, from February 2004 to February 2005 to evaluate the efficacy and ability of the less hazardous herbicides, glufosinate ammonium and glyphosate, as an alternative to the hazardous herbicide, paraquat, in controlling weeds in immature oil palm (<3 years old). The results showed that paraquat needed high rates, 600 and 800 g ha⁻¹, to control weeds effectively. However, lower rates of glufosinate ammonium (200 g ha⁻¹) and glyphosate (400 g ha⁻¹) gave excellent weed control. The results showed that the efficacy of glufosinate ammonium and glyphosate were much better than paraquat. The results also showed that, with no direct contact with the plants, paraquat, glufosinate ammonium, and glyphosate had no adverse effect on the vegetative and generative growth of oil palm in this study. These results proved that the less hazardous herbicides, glufosinate ammonium and glyphosate, could be used as an alternative to paraquat to control weeds in immature oil palm.     

唑嘧磺草胺、丙炔氟草胺与乙草胺混用的联合作用类型及对大豆田杂草的活性

为明确唑嘧磺草胺、丙炔氟草胺与乙草胺混用的联合作用特性及其对大豆田杂草的防除效果,采用温室盆栽法和田间药效试验,分别评价了混配组方的联合作用类型及对大豆田杂草的防除效果.温室盆栽试验结果表明:唑嘧磺草胺、丙炔氟草胺与乙草胺混用对稗草、马唐和苘麻的联合作用类型为相加作用,对反枝苋为相加或增效作用;当唑嘧磺草胺、丙炔氟草胺...     

Red rice (Oryza sativa L.) and barnyardgrass (Echinochloa spp.) biotype susceptibility to postemergence-applied imazamox

Pot experiments were conducted to evaluate the level of imazamox tolerance in five red rice ( Oryza sativa L.) and four barnyardgrass (three Echinochloa crus-galli (L.) Beauv. and one Echinochloa oryzoides (Ard.) Fritch) morphologically distinct biotypes collected from rice fields in northern Greece. The susceptibility of barnyardgrass biotypes to propanil was also studied. Red rice biotypes were not controlled by imazamox applied at 40 g ha⁻¹. In contrast, 80 g imazamox ha⁻¹ provided 56–84% red rice control (averaged across shoot number and fresh weight reduction). Not all barnyardgrass biotypes were susceptible to imazamox applied postemergence. However, propanil applied at 2.6 kg ha ⁻¹ controlled the E. crus-galli biotypes well, but propanil applied at rates of 2.6 and 5.2 kg ha ⁻¹ was not effective in reducing the shoot number and fresh weight of the E. oryzoides biotype. Propanil applied at 10.4 kg ha ⁻¹ reduced the shoot number and fresh weight of this biotype by 78 and 85%, respectively. In most cases, a linear equation ( y  = % of control, x  = g ha⁻¹) provided the best fit for regressions between red rice or barnyardgrass shoot number or fresh weight and imazamox rates. The results of this study suggest that postemergence application of imazamox is not effective against all red rice and barnyardgrass biotypes found in the rice fields of Greece and that significant variability regarding herbicide efficacy among biotypes might exist.     

Effect of the foliar application of diquat herbicide on selected natural area and field crop species

Field experiments were conducted to determine the non-target impact of foliar-applied diquat on selected plant species. Diquat was applied to emerged bracken fern, chain fern, slash pine, soybean, sunflower, cotton, corn, and onion at rates varying from 0.02–4.5 kg ai ha⁻¹ of diquat cation, which allowed for the determination of the no-effect rate and the rate that caused 25, 50, and 100% injury, as measured by visual injury ratings, plant heights, and dry weights. Bracken fern, chain fern, and slash pine were more tolerant to diquat and exhibited regrowth potential at the higher rates. The other six species were not only more susceptible to diquat, but they did not exhibit regrowth potential at high rates. However, these species were able to recover from slight injury caused by the lower rates of diquat.     

Plant sensitivity to atrazine and chlorsulfuron residues in a soil-free system

The sensitivity of 22 major crops, pastures and weeds from the north-east grain region of Australia to atrazine and chlorsulfuron residues was determined in a glasshouse using a soil-free bioassay system. A logistic equation was fitted to the seedling fresh weights as a function of the logarithm of herbicide concentration by non-linear regression and used to calculate the doses for 10%, 30% and 50% inhibition of seedling growth (ID₁₀, ID₃₀ and ID₅₀). The ID₅₀ for atrazine ranged from 0.03 to 0.04 mg a.i. L^–1 for Salvia reflexa Hornem. and barley to 1.47 mg a.i. L^–1 for sorghum. The ID₅₀ for chlorsulfuron ranged from 0.19 to 0.21 μg a.i. L^–1 for lucerne and snail medic to 102 μg a.i. L^–1 for wheat. Based on ID₅₀ values measured, the predicted responses of each species to a range of concentrations of atrazine and chlorsulfuron were classified into four categories ranging from no damage to severe damage. These sensitivity data will assist in planning cropping sequences in soils previously treated with atrazine or chlorsulfuron.     

Allelopathic potential of Trifolium resupinatum L. (Persian clover) and Trifolium alexandrium L. (Berseem clover)

This experiment was conducted in order to determine if Persian clover ( Trifolium resupinatum ) and Berseem clover ( Trifolium alexandrium ) contained water-soluble and methanol-soluble constituents that could affect the seedling growth of four test species; namely, Amaranthus retroflexus , Convolvulus arvensis (field bindweed), Secale cereale , and Sinapis arvensis (wild mustard) . The above-ground tissues of the Persian and Berseem clover plants were collected during the vegetative growth stage and oven-dried. Three concentrations of aqueous and methanolic extracts were used at full-strength (33.3 g L⁻¹), half-strength (16.7 g L⁻¹), and quarter-strength (8.3 g L⁻¹). Distilled water was used as the control. The weed seeds were placed in Petri dishes containing the legume extract or distilled water (control). The seedling growth of the weed species declined with the increasing concentration of the clover extracts. Wild mustard exhibited the highest sensitivity to both the legume extracts. Compared to the aqueous extract, the methanolic extract caused a greater decline in the seedling growth of the weeds. Berseem clover was the stronger inhibitor of the weed seedling growth, as compared to Persian clover. Therefore, the amounts of allelochemicals present might differ in these two clover species. Field bindweed showed the least sensitivity to both the legume extracts. Field bindweed showed more tolerance to the allelochemicals produced by the clover species.