Effect of Weed Control Methods on Weeds and Wheat (TriticumAestivum L.) Yield

A field experiment was conducted from June to December during 2010/11 crop season at HARC to study the effect of herbicides rates on weed dynamics and yield of wheat ( Triticumaestivum L.) variety “HAR 604” in randomized complete block design with three replications. the herbicides rates: clodinafop-propargyl(0.065,0.080, 0.105kgha -1 ) and isoproturon (1.00, 1.25, 1.50kgha -1 ), hand weeding at tillering and weedy checkwere used. The crop was infested with Avenafatua L . and Phalarisparadoxa L . among grass weeds and Cayluseaabyssinica Meisn , C. trigyna L ., Chenopodium album L. , Corrigoialacapensis Wild , Guizotiascabra (Vis) Chiov , Oxalis latifolia HBK , Polygonumnepalense L ., Raphanusraphanistrum L ., Spergulaarvensis L. and Tagetesminuta L. among broadleaved weeds. Hand weeding followed isoproturon at 1.50 kg ha -1 significantly reduced density and dry weight of weeds. Among herbicides, isoproturon provided better control of broadleaved and total weeds, whereas; clodinafop-propargyl proved better than isoproturon in controlling grass weeds. Hand weeding and hoeing at tillering resulted in lowest weed dry weight. Highest grain yield (2289.4 kg ha -1 ) in was recorded in hand weeding followed by isoproturon at 1.5kg ha -1 (2177.3 kg ha -1 ). The highest straw yield was recorded in hand weeding followed by isoproturon 1.50 kg ha -1 , and harvest index was also maximum with hand weeding. Maximum N-uptake was also recorded in these treatments. Post emergence herbicides and /or hand weeding and hoeing at tillering can further enhance the weed suppressive effect of the crop.