Bioefficacy of imazethapyr and chlorimuron-ethyl in clusterbean and their residual effect on succeeding rabi crops Punia S. S.1, Singh Samunder1, Yadav Dharambir1 1Department of Agronomy, CCS Haryana Agricultural University, Hisar-125 004 (Haryana), India Abstract Bioefficacy and phytotoxicity of imazethapyr and chlorimuron in clusterbean and its carryover effect on succeeding rabi crops was studied in field experiments at CCSHAU, Hisar during kharif 200607 and 2007–08. Weed flora of the experimental field was dominated by Digera arvensis, Trianthema portulacastrum, Physallis minima, Corchorus olitorius, Solanum nigrum and Cyperus rotundus. Postemergence application of chlorimuron at 6 and 8 g/ha although provided good (90–92%) control of weeds but caused 20–30% injury to clusterbean resulting in severe yield reductions. PPI (pre-plant incorporation), PRE (pre-emergence) and POE (post- emergence) application at 21–28 DAS at 80–100 g/ha of imazethapyr provided season long control (85–95%) of clusterbean weeds. POE application of imazethapyr at 80 and 100 g/ha although caused mild injury to clusterbean in terms of yellowing of leaves and stunted crop growth upto 7 DAT, but it diminished within three weeks without any yield reduction. Maximum seed yield (1424 kg/ha) of clusterbean was obtained with imazethapyr at 100 g/ha PRE which was at par with weed free check, but during 2007, PRE application of imazethapyr at 80 g/ha gave maximum seed yield (1720 kg/ha) which was at par with its application at 80 and 100 g/ha as PRE, PPI or post-emergence 21 DAS. Chlorimuron and imazethapyr, irrespective of their dose and time of application, did not cause any injury to wheat, barely and chickpea planted as succeeding crop after harvest of clusterbean, but both these herbicides caused severe injury to mustard. Top Keywords Efficacy, Crop injury, Residual effect, Mustard, Wheat, Barely, Chickpea. Top |