Energy budgeting and economics of weed management in dry direct-seeded rice

A field experiment was conducted at Main Research Station, Hebbal, Bengaluru during Kharif 2016 and Kharif 2017 to study the effect of different herbicide combinations and weed management methods on yield, energetics and economics of dry direct-seeded rice. The experiment consisted of 12 treatments and replicated thrice in RCBD design. Among various weed management treatments hand weeding at 20, 40 and 60 DAS recorded significantly highest paddy grain and straw yield in hand weeding at 20, 40 and 60 DAS (5.50 and 7.22 t/ha, respectively) and found at par with application of bensulfuron-methyl + pretilachlor as pre-emergence fb bispyribac-sodium (5.39 and 7.16 t/ha, respectively). Weedy check recorded significantly lowest yield (1.40 and 2.32 t/ha, respectively). Among the various herbicide combinations, sequential application of bensulfuron-methyl + pretilachlor as pre-emergence fb bispyribac-sodium was found to be the most energy and economically efficient weed management strategy in dry direct-seeded rice and had maximum value of total output energy (169090 MJ/ha), net energy returns (157444 MJ/ha), energy use efficiency (14.52), net returns (’ 59,276/ha) and benefit cost ratio (2.93).