Weed management in rice as influenced by nitrogen application and herbicide use

A field experiment was conducted for two consecutive rainy seasons of 2010 and 2011 at Varanasi (U.P.) to evaluate the effect of nitrogen application and weed management on transplanted rice and associated weeds. Puddled transplanting recorded significantly reduced weed density and heigher weed control efficiency at 60 days after transplanting (DAT) as compared to unpuddled transplanting. Butachlor 1.5 kg/ha followed by cono-weeding at 20 and 40 DAT recorded significantly higher plant height, no. of tillers/hill, dry matter accumulation, leaf area index, 1000-grain weight, no. of panicles/hill, grains/panicle and grain yield as compared to pretilachlor 0.75 kg/ha followed by azimsulfuron 35 g/ha at 15 DAT, and butachlor 1.5 kg/ha followed by azimsulfuron 35 g/ha at 15 DAT. Significantly higher yield components and rice grain yield were recorded with the application of 1/4 at 10 DAT, 1/2 at tillering and 1/4 N at panicle initiation as compared to conventional scheduling of nitrogen application.