Effect of Herbicide Combinations on Weed Control Efficacy and Grain Yield of Direct Seeded Rice

A field investigation was conducted during kharif2012 and2013, rabi 2012-13and 2013-14to evaluate the herbicide combination for control of complex weed flora in direct seeded rice at Tamil Nadu Agricultural University Farm, Coimbatore. The treatments comprised of pre emergence (PE)pendimethalin 1000 g/hawith either early post emergence (EPOE) bispyribac sodium 25 g/ha alone or with hand weeding on 45 DAS or hand weeding on 45 DAS alone, PE oxadiargyl 100 g/ha fbEPOE bispyribac sodium 25 g/ha, PE pyrazosulfuron 20 g/ha fb EPOE bispyribac sodium at 25 g/ha, EPOEbispyribac sodium 25 g/ha alone and with chlorimuron + metsulfuron 4 g/ha (tank mix) at 15 DAS and were compared with cono weeder weeding thrice on 20, 40 and 60 DAS, hand weeding on 20, 40 and 60 DAS and unweeded control. PE pendimethalin 1000 g/ha fbEPOEbispyribac sodium 25 g/ha at 25 DAS fb hand weeding on 45 DAS effectively reduced the weed density and dry weight and registered higher grain yield and net returns in direct seeded rice.