Assessment of new-generation herbicides for effective weed management, yield enhancement, and economic returns in direct-seeded rice

This study was conducted during the samba season 2023 to assess the effectiveness of selected new-generation herbicide formulations for weed management in direct-seeded rice, with emphasis on crop yield and economic returns. (cv. TKM 13). The experiment was laid out in a Randomized Block Design (RBD) with ten treatments and three replications. The treatments comprised integrated weed management strategies involving pre-emergence, early post-emergence, and post-emergence herbicide applications, either alone or in combination with hand weeding, and were compared with a weedy check and hand weeding twice at 15 and 30 DAS. Pre-emergence treatments included pretilachlor, pyrazosulfuron-ethyl, and a ready-mix of pretilachlor + pyrazosulfuron-ethyl, followed by hand weeding at 15 DAS. Early post-emergence options consisted of metsulfuron-methyl, bispyribac-sodium, triafamone + ethoxysulfuron followed by hand weeding, and metsulfuron-methyl + chlorimuron-ethyl followed by hand weeding at 30 DAS, while 2,4-D was applied as a post-emergence treatment. All herbicide-based treatments resulted in a significant increase in grain yield compared with the weedy check. Although manual weeding alone proved highly effective, its field-level adoption is constrained by escalating labour costs and limited labour availability. Among the chemical interventions, the early post-emergence application of triafamone + ethoxysulfuron at 40 g A.I. ha^-1 followed by hand weeding at 30 DAS emerged as the most effective and environmentally sustainable option. In addition to improving yield, this treatment sequence substantially enhanced economic returns, recording higher gross and net returns as well as a superior benefit-cost ratio, thereby establishing it as the most profitable and efficient weed management practice for increasing productivity in direct-seeded rice.