Bispyribac-Na, Chlorimuron-ethyl, Direct-seeded rice, Economics, Integrated weed management
A field investigation was conducted during Kharif season of 2014 and 2015 at Varanasi, Uttar Pradesh, to study the effect of integrated weed management on weed flora, yield and economics of direct seeded rice (Oryza sativa L.). Penoxsulam 35 g/ha at 10 DAS fb 1 hand weeding at 35 DAS reduced weed density of various weed flora, viz. Echinocloa colona (7.27%), Echinocloa crus-galli (6.58%), Cynodon dactylon (7.57%) among grasses; Cyperus iria (8.01%), Cyperus difformis (8.26%) and Fimbristylis miliacea (8.67%) among sedges and Ammannia baccifera (10.12%) and Caesulia axillaris (10.10%) among broad-leaved weeds besides other weeds (11.72%) in comparison to penoxsulam 35 g/ha at 20 DAS fb 1 hand weeding at 35 DAS. Penoxsulam 35 g/ha at 10 DAS fb 1 hand weeding at 35 DAS markedly improved growth attributes, viz. plant height, number of tillers/m2, dry matter accumulation, leaf area index and chlorophyll content at 60 DAS and yield attributes, viz. panicle length, panicle weight, number of panicles/m2, number of grains/panicle and test weight. Penoxsulam 35 g/ha at 10 DAS fb 1 hand weeding at 35 DAS statistically influenced the grain and straw yields and harvest index over all other treatments except hand weeding at 15 and 35 DAS. Highest net return (43790.76) and benefit: cost ratio (2.15) was also observed under penoxsulam 35 g/ha at 10 DAS fb1 HW at 35 DAS.