Effect of herbicides and their combinations on weed growth and yield of transplanted rice

Abstract

A field experiment was carried out at Norman E. Borlaug Crop Research Centre of G.B.P.U.A.& T, Pantnagar U.S. Nagar, Uttarakhand during Kharif season of 2012 and 2013 to find out the efficacy of different herbicide combinations in transplanted rice. The experimental site was silty clay loam in texture, medium in organic carbon (0.66%), available phosphorus (27.5 kg/ha) and potassium (243.5 kg/ha) with PH 7.3. Echinochloa colona, Echinochloa crus-galli, Leptochloa chinensis, Alternanthera sessilis, Ammania baccifera, Caesulia axillaris and Cyperus iria were the major weeds in experimental field. Bispyribac-sodium + ethoxysulfuron 25 + 18.75 g/ha having statically similar with pretilachlor 750 g/ha fb ready mix of chlorimuron-ethyl + metsulfuron-methyl 4 g/ha and bispyribac-sodium + ready mix of chlorimuron-ethyl + metsulfuron-methyl 20 + 4 g/ha resulted in significantly lowest total weed density, dry matter accumulation and highest weed control efficiency, respectively. The maximum grain yield was recorded with twice hand weeding at 25 and 45 DAT, which was statistically at par with bispyribac-sodium + ethoxysulfuron 25 +18.75 g/ha, pretilachlor 750 g/ha fb ready mix of chlorimuron-ethyl + metsulfuron-methyl 4 g/ha, bispyribac-sodium + ready mix of chlorimuron-ethyl + metsulfuron-methyl 20 + 4 g/ha and pretilachlor 750 g/ha fb ethoxysulfuron 18.75 g/ha over the weedy check.