Weed dynamics and crop productivity in kharif rice (Oryza sativa L.) under different establishment methods and herbicide treatments

The present study was conducted during the kharif season of 2024 at the Post Graduate Research Farm, M S Swaminathan School of Agriculture, Centurion University of Technology and Management, Paralakhemundi, Odisha. The objective was to evaluate the effect of herbicides on weed dynamics and crop productivity under different establishment methods. The experiment was laid out in a split-plot design with 2 main plots and 10 subplots, replicated thrice. The main plots consisted of 2 establishment methods: transplanted rice (TPR) and dry-seeded rice (DSR). Subplots included 5 weed management treatments: W1 to W5, comprising combinations of pre- and post-emergence herbicides, W4: hand weeding (HW) and a weedy check (W5), using the test variety RNR-15048. TPR exhibited superior weed suppression (35 % higher WCE), improved growth, yield attributes and recorded 33 % higher yield over DSR. Among weed control treatments, W3 (Pretilachlor 600 g ha-1 PE fb Pyrazosulfuron ethyl 10 % WP 20 g ha-1 at 20 DAT/S) was most effective, with 83–93 % weed control efficiency which was only 5–18 % less than HW. Though HW achieved the highest yield, W3 registered the highest benefit-cost (B:C) ratio of 1.66, outperforming HW due to reduced labour dependency, which resulted in a 41 % lower B:C ratio in HW. Despite higher cultivation costs, TPR showed a 33 % higher B:C ratio than DSR. Thus, W3 in either TPR or DSR is recommended as a labour-saving and cost-effective weed management strategy, especially vital amidst growing labour scarcity in Indian agriculture.