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 AvenafatuaL. and PhalarisparadoxaL. among grass weeds andCayluseaabyssinicaMeisn,C. trigynaL., Chenopodium album L., Corrigoialacapensis Wild, Guizotiascabra(Vis) Chiov, Oxalis latifoliaHBK, PolygonumnepalenseL., RaphanusraphanistrumL., SpergulaarvensisL. 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.