Efficacy of new generation herbicidal combination for weed management in direct seeded rice (Oryza sativa L.)

Weeds are the main yield limiting factor that can potentially reduce crop yields and is one of the main constraints in the larger scale implementation of direct seeded rice. Therefore, the present experiment was conducted at Periyanarkunam during Navarai 2021 to study the efficacy of new generation herbicidal combination for weed management in direct seeded rice. The experiment was laid out in split plot design replicated thrice with main plot treatments comprised of three direct seeded rice establishment methods viz., dry seeded, drum seeded and manual wet seeded rice. The sub-treatments were nine weed management practices with combination of herbicides with hand weeding viz., Pre-emergence application of bensulfuron methyl 0.6%+pretilachlor 6% GR @ 10 kg/ha on 8 DAS (Days after sowing), early post- emergence application of triafamone 20%+ethoxysulfuron 10% WG @ 200 g/ha on 12 DAS, post-emergence application of metsulfuron methyl 10%+chlorimuron ethyl 10% @ 20 g/ha on 25 DAS, twice hand weeding on 25 and 45 DAS and un-weeded check. Among the main treatments, drum seeded rice recorded lower weed population and dry matter production, higher weed control efficiency, weed control index, crop resistance index and herbicide efficiency index and higher grain yield which was at par with manual wet seeded rice. Regarding the weed management practices evaluated pre-emergence application of bensulfuron methyl 0.6%+pretilachlor 6% GR @ 10 kg/ha on 8 DAS fb (followed by) post-emergence application of metsulfuron methyl 10%+chlorimuron ethyl 10% @ 20 g/ha on 25 DAS fb hand weeding on 45 DAS (S8) registered lower weed population, dry matter and higher yield compared to unweeded check. Hence, drum seeded rice coupled with pre-emergence application on 8 DAS fb post-emergence application on 25 DAS fb hand weeding on 45 DAS (M2S8) is an economically feasible method for effective control of weeds.