Studies on Sesbania, rice residue mulching and post emergence herbicides on weed growth and yield in unpuddled transplanted hybrid rice

Weeds are a major threat in unpuddled transplanted rice during rainy seasons. To manage weeds by using Sesbania residue green mulch, rice straw mulch and post emergence herbicides in an integrated way, an experiment was conducted in a split plot at Varanasi during the rainy season of 2017 and 2018. The experiment was taken with three mulching treatments in main plots, namely, no mulching (NM), cover crop of Sesbania aculeatea followed by its green residue mulch (SRGM) and rice straw mulch (RRM) in inter rows and five weed management treatments, namely, weedy, hand weeding twice (HWT), post emergence application of bispyribac 25 g a.i ha⁻¹ (BP), penoxsulam 30 g a.i ha⁻¹ (PX), bispyribac 25 g a.i ha⁻¹ + pyrazosulfuron 20 g a.i ha⁻¹ (BP + PS) in subplots replicated thrice. SRGM and RRM were noted to be successful in reducing density and biomass of grasses including Echinochloa colona and sedges and total weed (59% and 49%) biomass compared to NM under weedy conditions. Mulching, integrated with post emergence herbicides proved its potency in not only weed reduction but is also in yield enhancement.