Effect of New Molecules of Herbicide on Weed Infestation, Growth and Yield of Kharif Rice

The research was conducted to study the effect of different herbicides on weed infestation, growth and yield of kharif rice. Field trail was conducted during the kharif season of 2020 at the Instructional Farm, Jaguli, Bidhan Chandra Krishi Viswavidyalaya, West Bengal, under a randomized block design with nine treatment combinations. The variety Satabdi (IET-4786) was selected for the experiment and transplanted with the spacing of 20 cm × 10 cm. Treatments included various doses of UPH-814, a combination of bensulfuron methyl and pretilachlor, pyrazosulfuron ethyle, pretilachlor and hand weeding. The predominant weed species included Cynodon dactylon, Echinochloa spp., Cyperus spp., and various broadleaved weeds. Results showed that hand weeding achieved the lower weed population at all growth stages, among herbicidal treatments, particularly the combination of bensulfuron methyl and pretilachlor (T6) which result highest weed control efficiency at 60 DAT (80.77%) and UPH-814 (T3), were highly effective in controlling weed flora.Among all the herbicidal treatments minimum weed population at 30 DAS, 45 DAS, 60 DAS obtained in T3, pre-emergence application of UPH 814 (S) @ 2500 g ha-1. These treatments also resulted in the highest dry matter accumulation (810.90 g/m-2) at the time of harvest, grain and straw yields, with T6, Bensulfuron methyl 0.6%+ Pretilachlor 6% GR @10000 g/ha achieving a grain yield of 3.67 t/ha and a straw yield of 4.31 t/ha. Thus, UPH-814 and the combination of bensulfuron methyl and pretilachlor are promising options for effective weed management in kharif rice.