Effect of wood chip application on root growth of oak seedling and weed control in northern Iran

It was hypothesized that wood chips can serve as a mulch to improve the growth of young trees by facilitating the development of their root systems, inhibiting weed germination, and suppressing weed growth. The present study was carried out in Ghorogh Nursery, Golestan Northern Iran, in order to investigate the impact of wood chips applica- tion on root growth of oak （Quercus castaneifolia） seedlings and control of weed. A three centimeter wood chip layer was used on the soil surface as the mulch treatment with bare soil as the control. The number of new roots, the length of exciting roots and the density of weeds were meas- ured after 5 and 12 weeks. Results showed that wood chip application had significant positive effect on the length of excising roots after 5 and 12 weeks compared with control seedlings. Also, weeds were reduced to near zero levels in treated plot. Our findings suggested that wood chip layer on the soil surface in the nursery can conserve soil moisture and prevent nutrient leaching from the rooting zone as well as diminish weed growth which consequently lead to production of high quality seedling.

The influence of stocking levels,clone,fertilization,and weed control on surface CO_(2)efflux in a mid-rotation Pinus radiata D.Don plantation in Canterbury,New Zealand

Silvicultural practices applied in managed forest plantations may help counteract the effects of climate change by influencing soil surface CO_(2)efflux(Fs).Understanding the effects of silvicultural practices on Fs will provide unbiased estimates of carbon fluxes and allow better silvicultural decisions for carbon sequestration.Therefore,we assessed how Fs differed seasonally across silvicultural practices(i.e.,stocking levels,clone,fertilization and weed control treatments)and evaluated the effects of soil temperature(Ts)and soil volumetric water content(θv)on Fs across these practices for a mid-rotation(14 year-old)Pinus radiata plantation in the Canterbury region of New Zealand.There were significant differences in Fs(p<0.05)over the four seasons,three levels of stocking,and five clones.The effects of fertilization and weed control applied 12 years previously on Fs were insignificant.Annual estimate of Fs(mean±1 standard deviation)from the study site was 22.7±7.1 t ha^(-1)a^(-1)in the form of CO_(2)(6.2±2.1 t ha^(-1)a^(-1)in the form of C).Fs values were consistently higher in plots with 1250 stems ha^(-1)compared to 2500 stems ha^(-1),which may be related to a strong soil resource limitation because of the close spacing in the latter plantation.Significant differences in Fs across clones suggest that variations in carbon partitioning might explain their growth performance.Silvicultural treatments influenced Fs response to soil temperature(p<0.05),resulting in models explaining 28-49%of the total variance in Fs.These findings provide insights into how silvicultural management decisions may impact Fs in mid-rotation radiata pine plantations,contributing towards developing more precise and unbiased plantation carbon budgets.

A Computer System for Forecasting the Threshold Period for Crop Weed Control

In this article, a model of a weed control threshold forecast system has been established, with related model solving, data checking, database setting up, and system engineering illustration. Moreover, it is tested by a software with data from a sugar cane planting experimental field in Yunnan, China. The methodology behind the detailed system analysis, design, and engineering has been discussed. The issue of how to create a dynamic data-dependent forecast model of a threshold forecast system, whose threshold changes according to the change of planting environment has been solved. Hence an effective solution has been initiated for further development on an agricultural expert system.

Effects of Different Herbicides on Weed Control,Agronomic Characters and Grain Quality of Coix lacryma-jobi L.

[Objectives]The paper was to study the effects of different herbicides on weed control,agronomic characters and grain quality of Coix lacryma-jobi L.[Methods]Six commonly used herbicides were selected for the trial,including atrazine SC,butachlor SC,monosulfuron WP,MCPA-starane EC,clopyralid AS and tribenuron-methyl WP.[Results](i)Atrazine,butachlor and monosulfuron had no chemical injury to C.lacryma-jobi L.,while clopyralid caused slight chemical injury.(ii)The fresh weight control effects of atrazine,butachlor and monosulfuron on weeds increased first and then decreased.The initial control effect of MCPA-starane and clopyralid reached more than 90%;the control effect of monosulfuron increased gradually in the late stage,reaching 97%at 60 d post spraying,and the overall control effect was optimal.(iii)Compared with manual weeding,herbicides had no significant effect on plant height of C.lacryma-jobi L.However,compared with no weeding,other herbicides except tribenuron-methyl inhibited plant growth to a certain extent.Herbicides had different effects on main stem diameter,tiller number per plant and grain number per plant of C.lacryma-jobi L.(iv)Different herbicides had no significant effect on 100-grain weight,but had significant effect on yield.(v)Compared with manual weeding,atrazine,butachlor and clopyralid decreased the protein content of C.lacryma-jobi L.,and the use of atrazine,butachlor,monosulfuron,MCPA-starane and tribenuron-methyl decreased the fat content of C.lacryma-jobi L.;butachlor and MCPA-starane decreased the glycerol trioleate content of C.lacryma-jobi L.Compared with no weeding,chemical herbicides had no significant effect on the protein content,while atrazine decreased the fat content,and butachlor and MCPA-starane decreased the glycerol trioleate content of C.lacryma-jobi L.[Conclusions]The use of herbicides significantly increases crop yield compared with no weeding,but has an impact on agronomic characters and grain quality.

Weed Control Strips Influences on the Rubber Tree Growth

Hevea brasiliensis (rubber tree) is the most widely cultivated tree species for producing natural rubber latex whose productivity can be reduced by weeds. Field experiment was carried out during two years to evaluate the growth of rubber tree plants submitted to different weed control strips (0-weed-free, 50, 100, 150, 200, 250, 300, 350, and 400-(weedy cm) and to determine the critical width of weed control strip during the establishment of rubber tree plantation. Weed community was composed mainly by Urochloa decumbens (90%). The width of the weed control strip influenced on the initial plant growth of rubber trees, reducing the plant height, stem diameter, leaf area, and aboveground dry mass accumulation. In consequence, crop plantation was affected by the width of weed control. The critical width of the weed control strip for establishment of a rubber tree plantation was within 100 cm.

Influence of Post Emergence Application of Glyphosate on Weed Control Efficiency and Yield of Transgenic Maize

Field experiment was conducted during kharif 2009 and rabi 2009-2010 at Tamil Nadu Agricultural University, Coimbatore to evaluate the weed control efficiency and yield potential of glyphosate resistant transgenic maize. Treatments consisted of two transgenic maize hybrids named Hishell and 900 M gold with application of glyphosate as post emergence at 900, 1800 and 3600 g a.e/hathese were compared with non-transgenic counterpart maize hybrids with application of atrazine as pre-emergence at 0.5 kg/ha followed by one hand weeding at 40 Days After Sowing along with need based insect control practices. Post emergence application of glyphosate at 900, 1800 and 3600 g a.e/ha in transgenic maize hybrids was recorded with lower weed density and higher weed control efficiency compared to other treatments. Higher grain yield was recorded with post emergence application of glyphosate at 1800 g a.e/ha in transgenic hybrid 900 M Gold and 3600 g a.e/ha in transgenic hybrid Hishell during kharif 2009 and rabi 2009-2010 seasons, respectively.

Evaluation of New Formulation of Oxyfluorfen (23.5% EC) for Weed Control Efficacy and Bulb Yield in Onion

A field experiment were conducted for two years at Agricultural Research Station, Bhavanisagar of Tamil Nadu Agricultural University, during kharif season of 2009 and 2010 to evaluate the new formulation of oxyfluorfen (23.5% EC) on weed control in onion. Weeds constitute one of the biggest problems in agriculture that not only reduce the yield and quality of onion but also utilize essential nutrients. Hence, weed control is essential for increasing onion production. Based on two years field experimentation, it was found that pre-emergence application of oxyfluorfen (23.5% EC) at400 g.ha-1 gave significantly lower total weed density, weed dry weight and higher weed control efficiency at all the intervals. Application of new formulation of oxyfluorfen (23.5% EC) at200 g.ha-1 as pre-emergence herbicide can keep the weed density and dry weight below the economic threshold level and increase the bulb weight (42.56 and43.87 g) and yield (15940 and15610 kg.ha-1) in onion. Unweeded control accounted for lower bulb yield which inturn reflected through higher weed index of 60.6 and 56.1 per cent, respectively during both the years, due to heavy competition of weeds for nutrients, space and light.

Influence of Rice Residue Management Techniques and Weed Control Treatments on Soil Available Plant Nutrients in Rice-Wheat Cropping System

Rice-wheat is the predominant cropping system of fertile soils of Indian, Pakistan, Bangladesh and Nepal falling in the alluvial Indo-Gangetic Plains (IGP). Management of rice residues produced after the harvest of rice crop and before sowing of the next wheat crop is a big challenge in that area. Mostly farmers burn rice residues assuming it low profile fodder and of little use. Burning of rice residues deprives the fields from many plant nutrients as they are lost during burning along with environmental pollutions and other issues. A field study was conducted for two consecutive years at the experimental area of the Department of Agronomy, Punjab Agricultural University, Ludhiana (India) to assess the impact of different rice residue management techniques and weed control treatments in wheat on soil available plant nutrients in rice-wheat cropping system. The experiment was laid out in split plot design with three replications. In main plots, five rice residue management treatments viz., no rice residue, rice residue 5 t·ha-1 (surface), rice residue 6 t·ha-1 (surface), rice residue 7 t·ha-1 (surface) and rice residue 5 t·ha-1 (incorporation) were settled and in sub plots, four weed control treatments i.e. clodinafop 60 t·ha-1, sulfosulfuron 25 t·ha-1, mesosulfuron + iodosulfuron 12 t·ha-1 and control (unweeded) were arranged. Results of the study revealed that surface application as well as incorporation of rice residues improved the organic carbon and NPK status than no rice residues. Among the residue management practices, incorporation of rice residues 5 t·ha-1 significantly improved the soil organic carbon, available nitrogen, phosphorus and potassium than no rice residue treatment in the 0 - 15 soil layer during both the years. Same trend was observed for 15 - 30 cm soil layer but differences were less wide than 0 - 15 cm soil layer. Among the weed control treatments, organic carbon was not significantly influenced. Herbicide treated plots registered significantly higher available nitrogen, phosphorus and potassium than control (unweeded) treatment in the 0 - 15 cm soil layer during both the years.

Effects of Different Herbicides on Maize Growth and Weed Control in Maize Fields

Effects of four herbicides(paraquat, acetochlor, nicosulfuron and atrazine) on the growth of maize and control effect of plant quantity and fresh weight of weeds were studied. The results showed that 15 days after spraying the herbicides on weeds,the prevention and control effect of paraquat on weeds was the optimum, and its effects on the plant quantity and fresh weight of weeds were above 81.57%; the prevention and control effect of acetochlor on weeds was the second best; the prevention and control effect of atrazine on weeds was the worst, and its effects on the plant quantity and fresh weight of weeds were only 51.04% and 37.86%. After 30 or 45 days, the prevention and control effect of atrazine and nicosulfuron on weeds in the maize fields was better than the other herbicides, and their effects on the plant quantity and fresh weight of weeds were higher than 70.00% and 85.00%. Acetochlor and paraquat had certain phytotoxicity to the growth of maize after about 15 days, and its leaves became yellow and grew slowly. On the whole, nicosulfuron had good prevention and control effect on weeds and had no phytotoxicity to the growth of maize.

Weed Control Efficacy and Citrus Response to Flazasulfuron Applied Alone or in Combination with Other Herbicides

Field experiments were conducted to evaluate the phytotoxicity of flazasulfuron on citrus species and efficacy on weeds when applied alone or in combination with other herbicides. Grapefruit was the most sensitive and tangerine was the least sensitive to flazasulfuron. Injury to grapefruit was 70% with the application of flazasulfuron at 0.20 kg a.i. ha–1 at 60 DAT and was reduced (5%) when flazasulfuron at 0.05 kg a.i. ha–1 was tank mixed with glyphosate at 0.84 kg·a.i.· ha–1. Flazasulfuron alone at all rates did not control grass weeds and common ragweed. Florida/Brazil pusley was moderately controlled with high rates of flazasulfuron from 30 to 45 DAT;however, control did not exceed 75%. There was good control of Spanishneedles (78% - 85%) and horseweed (73% - 81%) with flazasulfuron at all rates at 30 DAT but control declined later in the season. Tank mix of flazasulfuron with glyphosate improved flazasulfuron efficacy on grass and broadleaf weeds. Flazasulfuron at 0.07 kg a.i. ha–1 plus glyphosate at 1.70 kg a.i. ha–1 was more effective in controlling grass weeds (83%) at 60 DAT and provided the highest control (79%) of Florida/Brazil pusley at 45 DAT. There was excellent control (75% to 94%) of Spanishneedles and adequate control of eastern black nightshade and common ragweed with flazasulfuron tank mixed with glyphosate or diuron. This study showed that flazasulfuron alone does not adequately control grasses and some broadleaf weeds in citrus and tank mixing it with glyphosate or diuron improved flazasulfuron’s efficacy. However, injury to grapefruit was observed at rates which effectively controlled weeds. Further studies are needed to determine the most suitable flazasulfuron rate that could be used to manage weeds in grapefruit.

Evaluation of Preemergence Herbicides for Crop Safety and Weed Control in Safflower

Weed management in safflower (Carthamus tinctorious L.) is a major challenge for growers due to very limited herbicide options available, particularly for broadleaf weed control. Field experiments were conducted at the Montana State University Southern Agricultural Research Center (MSU-SARC) near Huntley, MT in 2015 and 2016 to evaluate preemergence (PRE) soil-residual herbicides for crop safety and season-long broadleaf weed control in safflower. Among all herbicide programs tested, only sulfentrazone (105 g&middot;ai&middot;ha-1) alone or with pendimethalin (1064 g&middot;ai&middot;ha-1) caused 4% to 12% early-season visible injury to safflower, although the injury was not evident beyond 30 DAT. Sulfentrazone alone or with pendimethalin and pyroxasulfone (59 g&middot;ai&middot;ha-1) with pendimethalin had a season-long residual activity on kochia [Kochia scoparia (L.) Schrad] and Russian-thistle (Salsola tragus L), with 89% to 99% control at 60 DAT, and up to 98% reduction in weed density compared with dimethenamid-P (213 g&middot;ai&middot;ha-1) and S-metolachlor (433 g&middot;ai&middot;ha-1) at 65 DAT. Pyroxasulfone (59 or 118 g&middot;ai&middot;ha-1) alone or dimethenamid-P with pendimethalin provided a moderate to good control (65% to 79% at 60 DAT) of kochia and Russian-thistle. However, the end-season control of kochia or Russian-thistle was inadequate ( S-metolachlor alone program. Safflower grain yield with sulfentrazone alone or with pendimethalin, pyroxasulfone alone or with pendimethalin, and dimethenamid-P with pendimethalin averaged 3559 kg&middot;ha-1, which was 195% higher compared with the nontreated check. In conclusion, sulfentrazone and pyroxasulfone or dimethenamid-P in combination with pendimethalin will be effective PRE herbicide programs for kochia and Russian-thistle control in safflower.

Evaluation of Weed Control Efficacy and Seed Cotton Yield in Glyphosate Tolerant Transgenic Cotton

Cotton is one of the important crops that have been genetically altered to address challenges with weed and insect control. The research was conducted with glyphosate resistant cotton hybrids during winter irrigated season of 2009-10 and 2010-11 at the experimental site of Tamil Nadu Agricultural University, Coimbatore, with the objective, to find out the weed control efficacy and yield of transgenic cotton hybrid with the application of glyphosate. Glyphosate was applied as post-emergence application on 25 and 65 DAS at 900, 1350, 1800, 2700, 3600 and 5400 g a.e./ha in MRC 7347 BG-II RRF test hybrid. These treatments were compared with hand weeding on 15 and 30 DAS and unweeded control. In both sprays, post-emergence application of glyphosate 2700, 3600 and 5400 g a.e./ha registered lower weed density and higher weed control efficiency in transgenic cotton hybrid compared with other treatments. Seed cotton yield (3195 and 3092 kg·ha-1 during 2009-10 and 2010-11 respectively) was significantly higher in post-emergence application of glyphosate at 2700 g a.e./ha. Increased use of transgenic cotton with herbicide and pest resistance has resulted in more efficient insect and weed management practices.

Weed Control, Environmental Impact, and Net-Profit of Two-Pass Weed Management Strategies in Dicamba-Resistant Soybean (<i>Glycine max</i>) Using Conventional Tillage

Traditional two-pass weed management strategies need to be compared with new strategies in glyphosate/dicamba-resistant soybean. Weed control, soybean yield, partial profitability and environmental impact (EI) were evaluated in glyphosate/dicamba-resistant soybean using dicamba applied alone or in a tank-mix with dimethenamid-P applied preemergence (PRE). Trials were conducted at three locations during 2014 and 2015. Several PRE herbicides provided excellent control of broadleaf and grass weeds. Dicamba provided > 91% control of broadleaf weeds, and the addition of dimethenamid-P improved grass control. All weed species at the trial locations were controlled > 94% following a postemergence (POST) application of glyphosate. Weed interference reduced soybean seed yield 33% where no herbicide was applied. A single POST application of glyphosate had the lowest EI. Several treatments improved early-season weed control and reduced early-season weed density and biomass compared to glyphosate and had similar EI values. In this study, there was no benefit to yield or partial profit by including a PRE herbicide for weed management;however, the inclusion of multiple modes-of-action in a herbicide program may reduce the selection for herbicide-resistant weeds.

Weed Control Practices and Varying Sowing Dates Effects on Seed Production of Pearl Millet (<i>Pennisetum americanum</i>L.) under Semi-Arid Environment

Peral millet being drought tolerant has substantial potential to contribute in food security ensuring the food, fodder and nutritional value in different Asian and African countries. Susceptibility to abiotic and biotic factors and low productivity are the main reasons for decreasing productivity and area of millets. In this context, evaluation of the effect of weed control practices and varying sowing dates on grain yield of kharif season grown pearl millet (Pennisetum americanum L.) was demonstrated at post graduate agriculture research station, University of Agriculture, Faisalabad during 2015. Forage pearl millet was sown at three different sowing dates i.e. mid-June, end of June and mid-July and four weed control practices viz. weedy check (no weeding), twice hoeing at 15 and 30 days after sowing (DAS), weed control using herbicides i.e. application of Atrazine (Awax 38 SC) &#64;330 g a.i. ha-1 at 15 DAS, and twice foliar applications of 10% Sorghum water extract (Sorgaab) (at 15 and 30 DAS). The experiment was laid out in randomized complete block design (RCBD) under split plot arrangement, comprising of three replications. The treatments with varying sowing dates were randomized in main plots and weed control practices were in subplots. Results showed that the highest plant height (279.51 cm), leaf area (2777.80 cm2), fresh weight of leaves per plant (155.57 g), maximum number of grains per head (3162.0) and grain yield (3419.7 kg&middot;ha-1) were obtained in the treatment combination of 30th June sowing × twice weed hoeing (at 15 and 30 DAS) while, maximum 1000-grain weight (8.45 g) was observed in treatments where weeds were controlled by hoeing (at 15 and 30 DAS). Moreover, cultural weed control practices reduce significantly weed density, fresh and dry Wight of weeds. In sum, it is concluded that to reduce the weed-crop competition and to gain higher productivity of pearl millet, field should be weed free 20 - 45 days after sowing.

Broadleaf Weed Control in Sunflower (<i>Helianthus annuus</i>) with Preemergence-Applied Pyroxasulfone with and without Sulfentrazone

A field study was conducted at two locations in Kansas, USA in 2011 and 2012 to test weed control efficacy and crop response to preemergence-applied pyroxasulfone alone and in combination with sulfentrazone in sunflower. Treatments included three rates of pyroxasulfone (100, 200 and 400 g·ha-1) applied alone and tank-mixed with sulfentrazone at 70, 140 and 280 g·ha-1. Commercial standards sulfentrazone at 140 g·ha-1 + pendimethalin at 1390 g·ha-1 and sulfentrazone at 140 g·ha-1 + S-metolachlor at 1280 g·ha-1 were also included. Pyroxasulfone at 100 g·ha-1 controlled Palmer amaranth 87% at 3 weeks after application (WAA), but control decreased to 76% at 6 WAA. Increasing pyroxasulfone rate to ≥200 g·ha-1 or tank mixing with sulfentazone at 140 g·ha-1 provided ≥90% Palmer amaranth control for at least 6 WAA. Sulfentrazone alone at 70 g·ha-1 controlled Palmer amaranth 77% at 3 WAA, but control dropped to 69% at 6 WAA. Increasing sulfentrazone rate from 70 to 140 or 280 g·ha-1 increased control to >90% at 3 WAA, but did not maintain acceptable control at 6 WAA. Tank mixing sulfentrazone at 140 g·ha-1 with pendimethalin at 1390 g·ha-1 or S-metolachlor at 1280 g·ha-1 controlled Palmer amaranth ≥90 and 84% at 3 WAA and 6 WAA, respectively. The lowest rate of pyroxasulfone (100 g·ha-1) controlled kochia 98% and the control was complete with all other treatments. However, no treatment provided as much as 90% puncturevine control at 3 WAA and the control was commercially unacceptable (<75%) at 6 WAA. No treatment visibly injured sunflower anytime during the season or reduced sunflower plant population.

Field experimental study on pullout forces of rice seedlings and barnyard grasses for mechanical weed control in paddy field

Pullout forces of rice seedling and barnyard grass were tested by universal testing machine controlled by WDW-5 type microcomputer to obtain the pullout forces of rice seedling and barnyard grass.The measured pullout force was used to improve the weeding rate and reduce the rice seedling damage rate caused by mechanical weeding device.According to the measured continuous curve of pullout forces of rice seeding and barnyard grasses in weeding period,the best range of force required to pull out barnyard grasses from soil with no injury and damage to rice seedlings was discussed.Reasons for the difference in the pulling force were analyzed.Results show that,with the increment of the number of single cell rice seedlings the pullout force increases.The pullout forces of single cell rice seedlings and barnyard grasses at first increased slowly reaching the maximum value followed by rapid drop and finally it remained steady.The minimum pullout forces recorded during rice seedlings at the first and the second weeding periods were 2.57 N and 9.70 N,respectively,while the minimum forces during the first and second weeding periods were recorded as 1.24 N and 7.51 N,respectively,for barnyard grasses.The results show that the pullout forces of weeding to rice seedlings and barnyard grasses should be within 1.24 N to 2.57 N and 7.51 N to 9.70 N respectively in the first and second weeding periods.

Comparison of efficiencies and costs of different weed control methods in paddy production in Iran

Using of efficient and inexpensive method for weed control has an important role in increasing efficiency and reducing costs of production.In this study,field experiments were carried out to evaluate the efficiency and costs of several weed control methods in paddy production during summer in Mazandaran,the north province of Iran in 2011.Seven weed control treatments(T1 to T7)were applied at three stages of rice growth(20 and 35 days after transplanting and grain harvesting time).Weed density,weed dry weight,labor used and economical comparison were determined in the basis of a complete randomized block design with three replications.Results showed that there were no significant differences among efficiencies of six treatments(except for weedy check method(T6)treatment).The minimum weed density and dry weight were obtained at herbicide+hand weeding once(T5)and herbicide application once(T7)treatments during all three stages.The costs of weed control were different among the treatments.Selection of control method has an important role in reducing labor.Hand weeding twice method(T1),because of its high weeding cost,hard work and worker restriction in the required time,is not useful.Powered weeding twice method(T2),due to its zero environment pollution,reducing costs of weed control and high benefit/cost,is the best and most appropriate treatment.Amount of weed damage in weedy check method(T6)varied between 30.5%and 45.3%.

Weed control through allelopathic crop water extracts and S-metolachlor in cotton

Weeds are one of the most important biological constraint to cotton production,and result-ing in a yield losses of up to 90%.The evolution of hundreds of resistant weed species,the lack of new herbicide chemistries,and the increase in weed management costs are all mak-ing weed management more arduous for the growers.Hence,a field experiment was con-ducted to investigate the efficacy of allelopathic crop water extracts(ACWEs)alone and in combinaton with one third rate of S-metolachlor 717g ai.ha-1for effective weed man-agement in cotton.The treatments investigated were;weedy check,sorghum+brassica water extract(WE)at 1.5Lha 1,sorghum+sunflower WE at 1.5Lha-,sorghum+bras-sica+sunflower WE at 1.5Lha-1,sorghum+brassica WE at 15L ha-1+S-metolachlor at 717 g a.i.ha-l,sorghum+sunflower WE at 1.5L ha-1+S-metolachlor at 717 g a.i.ha-1,sor-ghum+brassica WE+sunflower WE at 1.5Lha-1+S-metolachlor at 717 gaiha-,and S-metolachlor at recommended rate of 2.15 kg ai.ha-1.Results revealed that pre-emergent application of sorghum+brassica water extract(WE)at 1.5L ha-1 was the best treatment in terms of effective dry biomass reduction(40%)of Trianthema portulacastrum and Cyperus rotundus,and increase in seed cotton yield(12%).The second best treatment was sorghum+sunflower WE at 1.5Lha-1+S-metolachlor at 717g ai.ha-1 with yield increase of 11%over the weedy control.In comparison,S-metolachlor at recommended rate 2.15kg a.i.ha-1 recorded only 4%decrease in weeds dry biomass reduction and 8%increase in seed cotton yield.Hence,it can be predicted that binary combinaton of sorghum and brassica WE at 1.5 Lha-1 or binary combination of sorghum+sunflower WE at 15Lha-1 with one third dose of S-metolachlor (717g aiha-l)can be used for effective weed management and increase in seed cotton yield.Furthermore,adoption of this technique will also reduce the herbicide application,which is not only benefcial for the ecosystem but,also minimize the evolution of herbicide-resistant weed species.