Strategic Integration of Rice Residue Mulch, High Seeding Rates and Pre‐Emergence Herbicide Mixtures for Weed Management in Zero‐Till Wheat

ABSTRACT Weed management in wheat is becoming more difficult due to declining effectiveness of post‐emergence (POST) herbicides. Although pre‐emergence (PRE) herbicides remain effective, a single application is insufficient to control all weed cohorts. Field studies were conducted in India to combine PRE herbicides with non‐chemical measures for weed control. The experiment was conducted in a split‐split plot design with three levels of rice residue mulch (0, 4, 8 t ha −1 ) in main plots, two wheat seeding rates (100 and 125 kg ha −1 ) in sub‐plots and five weed control treatments‐ pendimethalin + metribuzin (PRE), pendimethalin + metribuzin followed by ( fb ) sulfosulfuron + metsulfuron (POST), pyroxasulfone (PRE) fb sulfosulfuron + metsulfuron (POST), weed‐free control and weedy check in sub‐sub plots. Results revealed that rice residue mulching at 8 t ha −1 reduced the dry matter of Phalaris minor and broad‐leaved weeds by 48%–50% and 56%–60%, respectively, at 60 days after sowing (DAS) compared to weedy check. Similarly, a higher seed rate of 125 kg ha −1 reduced total weed biomass by 11%–14% compared to the lower seed rate at 60 DAS. The strategic integration of higher seeding density, 8 t ha −1 rice residue, and a PRE herbicide mixture (pendimethalin 1.5 + metribuzin 0.210 kg ha −1 , applied beneath the mulch) reduced total weed biomass by 98% and improved wheat productivity compared to weedy check, without mulch and lower seeding rate treatment combination. This study suggests for an integrated strategy tailored to the rice‐wheat system to manage weeds, rice residues and enhance wheat productivity.