Effect of Different Integrative Weed Management Tactics on Paddy (Oryza sativa L.) during kharif in terai Region of West Bengal

Abstract

Background: Now a days chemical control measures alone develops resistance in different weed species. Integrative weed management techniques are more effective and sustainable than chemical management. Based on these facts, a field experiment was conducted during kharif, 2019 and 2020 at Uttar Banga Krishi Viswavidyalaya to investigate the impact of integrative weed management treatments on growth attributes, yield attributes, yield, weed indices and economics of paddy. Methods: The experiment was laid out in randomized block design with four replications. In each replication, five integrated weed management treatments were done namely, pretilachlor + paddy weeder (P1), pyrazosulfuron followed by metsulfuron methyl + chlorimuron ethyl (P2), bispyribac sodium + paddy weeder (P3), completely no weed (P4) and No treatment (P5). Result: Among the chemical and integrative weed control options, bispyribac sodium + paddy weeder i.e., treatment P3 showed significantly better results than others in case of all the growth attributes and yield attributes except 1000-grain weight. Significantly higher grain yield than all other treatments were recorded in treatment P4 i.e., complete weed free (6.68 t ha-1) followed by treatment P3 i.e., bispyribac sodium + paddy weeder (6.54 t ha-1). Among all the treatments, weed indices like weed control index (80.17, 72.30 and 82.51% at 30, 45 and 60 DAT, respectively) and weed control efficiency (76.48, 79.01 and 80.79% at 30, 45 and 60 DAT, respectively) showed highest results on all the dates whereas weed persistence index at 90 DAT (0.91) and weed index (2.10%) were calculated lowest in treatment P3 i.e., bispyribac sodium + paddy weeder after treatment P4 i.e., completely no weed treatment. This study also indicated rice treated with P4 i.e., weed free showed highest gross return (₹116700 ha-1) and rice treated with P3 i.e., bispyribac sodium at 15 DAT + paddy weeder at 30 DAT showed highest net return (₹59269 ha-1) and benefit:cost (2.07).