Studies on effective herbicidal weed management practice in direct seeded rice under western Ghat zone

In direct seeded rice (DSR) cultivation, weed is the major constraint mainly due to absence of puddling in field. The yield loss due to weed interference is huge, may be up to 100%. In this perspective, the present experiment was conducted to study the “Studies on effective herbicidal weed management practice in direct seeded rice under western ghat zone”. The dry weight and density of weeds were recorded at different growth stages and consequently herbicide efficacy was evaluated. Experimental results revealed that pre-emergence (PRE) herbicide effectively controlled the germination of grassy weeds. Application bispyribac-sodium as post-emergence (POST) following PRE herbicides (Pyrazosulfuron ethyl or oxyflourfen) or as tank-mixture with metsulfuron methyl 10% + chlorimuronethyl effectively reduced the density and biomass accumulation of diverse weed flora in DSR. Herbicidal treatments improved the plant height, yield attributes and grain yield (2.7 to 4.2 times) over weedy check. Differences in sensitivity values of weed dry matter and WCE across the crop growth stages also suggest that at 15, 30 and 60 days after sowing, herbicides most effectively controlled sedges, broad leaves and grasses, respectively. Based on the grain yield and herbicidal WCE, it can be concluded that the combined application of PRE application (EPOST) of Pyrazosulfuron ethyl 10% WP0.030 kg a.i./ha at 8 DAS + application of Byspribic sodium 10% SC @ 0.030 kg a.i. /ha at 20 DAS or PRE application of oxyflourfen 23.5% EC @ 0.150 kg a.i/ha at 2-3 DAS.+ POST application of Byspribic sodium 10% SC @ 0.030 kg a.i. /ha at 20 DAS. as PRE followed by bispyribac-sodium as POST or tank-mixture of Pyrazosulfuron ethyl + bispyribac sodium can effectively control different weed flushes throughout the crop growth period in DSR.