Effect of Sequential Application of Herbicides in Direct-Seeded Rice Under Medium Black Soils of Konkan

A field experiment was conducted at the Agricultural Research Station, Repoli Dist. Raigad (Maharashtra) during the Kharif season of 2019, 2020 and 2021 to study the effect of sequential application of herbicides on weed population, yield and economics of direct seeded rice (Oryza sativa L.). The experiment was laid out in randomized block design with three replications and seven treatments, viz., Oxadiargyl 80 % WP (Pre-emergence, PE) @ 100 g ha-1, Oxadiargyl 80% WP (PE) @ 100 g ha-1 followed by (fb) hand weeding (HW) at 30DAS, Oxadiargyl 80% WP (PE) @ 100 g ha-1 fb Bispyribac-Na @ 25 g ha-1 at 25 days after sowing (DAS), Oxadiargyl 80% WP (PE) @ 100 g ha-1 fb Metasulfuron-methyl + chlorimuron-ethyl @ 4 g ha-1 at 25 DAS, Oxadiargyl 80% WP (PE) @100 g ha-1 fb Carfentrozone ethyl 40% @ 25 g ha-1 at 25 DAS. These weed control treatments were compared with hand weeding twice at 20 and 40 DAS weed-free check, and weedy check. Application of Oxadiargyl 80% WP (PE) @ 100 g ha-1 fb HW at 30 DAS recorded significantly lowest number of weeds m2, dry weight m2 and recorded the higher grain and straw yield (4.02 and 4.87 t ha-1 respectively) and B:C ratio (1.48). Among sequential herbicide treatments, application of Oxadiargyl 80% WP (PE) fb Metasulfuron-methyl + chlorimuron-ethyl @ 4 g ha-1 at 25 DAS recorded the least number of weeds m2 and dry weight m2 as compared to other sequential herbicide treatments.