Effect of herbicide and varying rates of straw mulching on weed dynamics, productivity and profitability of rice

In kharif 2022 and 2023 a field study was conducted in randomized complete block design with three replications for evaluating eleven treatments comprised of sole application of pendimethalin (750 g/ha) and bispyribac- Na (25 g/ha), rice straw mulch (RSM) (4, 6 and 8 t/ha), combination of pendimethalin along with variable rates of RSM, sequential application of pendimethalin fb bispyribac-Na and compared with weed free and weedy check. The study revealed that among the herbicidal and straw mulching treatments, the application of pendimethalin fb RSM 8 t/ha registered significantly the minimum density and biomass of total and all categories of weeds, except broad leaved weeds (BLWs) at 45 DAS. However, it was followed by the application of pendimethalin fb RSW 6 t/ha and pendimethalin fb bispyribac-Na application. The weed-free treatment registered the maximum weed control efficiency (WCE) and the minimum density and biomass of broad-leaved weeds, which was at par with pendimethalin fb bispyribac-Na treatment. Weed-free plot produced the maximum grain yield of 3.98 t/ha, which was at par with the application of pendimethalin fb straw mulching at 8t/ha (3.86 t/ha), pendimethalin fb bispyribac-Na (3.77 t/ha) and pendimethalin fb straw mulching at 6 t/ha (3.74 t/ha) treatments. Further, economic analysis revealed that the sequential application pendimethalin 750 g/ha (Pre) fb bispyribac-Na 25 g/ha (Post) fetch maximum net return (Rs.45,282/ha), which was followed by the integration of pendimethalin 750 g/ha fb RSM 6 t/ha (Rs.31,056/ha) in DSR. These treatments could manage the diverse weed flora and obtain higher grain yield and more significant profit in direct-seeded rice.