In situ green manuring and herbicide on weed biomass, productivity and profitability of upland rice

Field experiment was conducted at Agronomy Farm, College of Horticulture, Vellanikkara during Kharif (rainy season) 2019 to develop cost-effective weed management strategy for upland rice in Kerala. Treatments consisted of brown manuring (cowpea) by application of 2,4-D 1.0 kg/ha at 25 days after sowing (DAS); in situ green manuring (cowpea) at 25 DAS; oxyfluorfen 0.15 kg/ha on the day of sowing fb hand weeding (HW) at 30 DAS; oxyfluorfen 0.15 kg/ha on the day of sowing fb bispyribac-sodium 0.025 kg/ha at 20 DAS; pyrazosulfuron-ethyl 0.03 kg/ha at 6 DAS fb HW at 30 DAS; pyrazosulfuron-ethyl 0.03 kg/ha at 6 DAS fb bispyribac-sodium 0.025 kg/ha at 20 DAS. Hand weeded control and unweeded control were also maintained. Results revealed that application of oxyfluorfen at 0.15 kg/ha on the day of sowing fb hand weeding at 30 DAS recorded lesser weed density and dry matter production, higher grain (2.74 t/ha) and straw (5.89 t/ha) yields and net monetary returns. It was at par with pyrazosulfuron-ethyl 0.03 kg/ha at 6 DAS fb hand weeding at 30 DAS.