Herbicides for weed management in direct dry-seeded rice

A field experiment was conducted during Kharif seasons of 2010 and 2011 to evaluate the efficacy of different herbicides and their combinations in managing weeds of direct dry-seeded rice. The major weeds were Echinochloa colona, Echinochloa crus-galli, Leptochloa chinensis among grasses, Caesulia axillaris and Trianthema monogyna among broad-leaved weeds and Cyperus rotundus among sedge. The lowest total weed density was recorded with azimsulfuron 35 g/ha and cyhalofop-butyl + ready mix of chlorimuron + metsulfuron 60 + 20 g/ha, which were at par with each other followed by fenoxaprop + ethoxysulfuron 60 + 15 g/ha and twice hand weeding at 20 and 40 days after seeding (DAS). The lowest weed biomass was recorded with combined application of fenoxaprop + ethoxysulfuron 60 + 15 g/ha and fenoxaprop + ready mix of chlorimuron + metsulfuron 60 + 20 g/ha. The highest weed control efficiency was recorded with twice hand weeding at 20 and 40 DAS (89.9%) followed by fenoxaprop + ethoxysulfuron 60 + 15 g/ha, fenoxaprop + ready mix of chlorimuron + metsulfuron 60 + 20 g/ha, bispyribac-sodium 25 g/ha and fenoxaprop 60 g/ha over the weedy check. The higher grain yield (3.50 t/ha) was recorded with twice hand weeding (20 and 40 DAS), which was at par with fenoxaprop + ethoxysulfuron 60 + 15 g/ha followed by bispyribac-sodium 25 g/ha alone and fenoxaprop + ready mix of chlorimuron + metsulfuron 60 + 20 g/ha.