Efficacy of herbicides on weed dynamics and yield of direct seeded rice (Oryza sativa L.)

A field trial was conducted during the Kharif- 2024 at the Research cum Instructional Farm of Shaheed Gundadhur College of Agriculture and Research Station, IGKV, Jagdalpur, Chhattisgarh, to evaluate the effectiveness of various herbicides on weed dynamics and yield performance of direct seeded rice under rainfed conditions. The study was laid out in a Randomized Complete Block Design (RCBD) with ten treatments, each replicated three times. The findings of the study indicated that performing hand weeding twice, at 25 and 50 days after sowing (DAS), was the most effective method for reducing overall weed density (19.67 m-2) and the total dry weight of the weed flora (11.04 g m-²), while also significantly improving weed control efficiency. This treatment also resulted in the highest grain and straw yields (40.19 and 54.51 q ha-1, respectively). These results were statistically comparable to those obtained from the sequential application of Pendimethalin 38.7% CS @ 1000 g a.i. ha-1 fb Bispyribac Sodium 10% SC @ 25 g a.i. ha-1. Similar performance was also observed with Pretilachlor 50% EC @ 750 g a.i. ha-1 fb Bispyribac Sodium, as well as the sole application of Bispyribac Sodium. In contrast, the weedy check treatment showed the lowest performance across all evaluated parameters. Thus, the combination of Pendimethalin followed by Bispyribac Sodium proved to be an effective and economically viable weed control option for direct seeded rice.