Weed proliferation is one of the most critical yield‐reducing challenges in direct‐seeded rice (DSR) systems. The application of herbicides has emerged as a key strategy for effective weed control in DSR. Field experiments were conducted over 2 years to evaluate efficacy of various pre‐ and post‐emergence herbicides, applied individually as well as in different combinations. Results showed that the highest weed density and dry weight were recorded in the untreated control plots. Bispyribac sodium and fenoxaprop‐p‐ethyl provided selective control of sedges and grasses, respectively. The most effective weed biomass suppression (88%–93%) and highest paddy yields (3.33–3.51 t ha −1 ) were achieved with the sequential application of pendimethalin, bispyribac sodium, and fenoxaprop‐p‐ethyl. A tank mixture of bispyribac sodium and fenoxaprop‐p‐ethyl also showed statistically similar weed control (87%–91%) and grain yields (3.15–3.44 t ha −1 ). Season‐long weed competition in DSR led to a drastic yield reduction of 85–90%. The most favorable benefit‐cost ratios (0.26 in 2016 and 0.32 in 2017) were obtained with the pre‐emergence application of pendimethalin followed by a post‐emergence spray of bispyribac sodium and fenoxaprop‐p‐ethyl at 20 DAS. These findings suggest that an integrated herbicide strategy combining pre‐ and post‐emergence applications is the most effective and economical approach for weed management and yield maximization in direct‐seeded rice.
Hussain et al. (Fri,) studied this question.