Weed control in clusterbean through post-emergence herbicides

Field experiment was conducted at Bikaner for two consecutive years during Kharif seasons of 2012 and 2013 to test the efficacy of different weed control measures against weeds in clusterbean Cyamopsis tetragonoloba (L.) Taub. The experiment consisting of seven treatments, viz. imazethapyr 40 g/ha, quizalofop-ethyl 37.5 g/ha, fenoxaprop-p-ethyl 50 g/ha, imazethapyr + imazamox 40 g/ha, pendimethalin 0.75 kg/ha as pre-emergence (PE), hand weeding twice at 20 and 40 DAS and weedy check. Among herbicids, post-emergence application of imazethapyr + imazamox (ready mix) 40 g/ha applied at 3–4 leaf stage (around 20 DAS) recorded lowest weed density and dry weight of both grassy and broad-leaved weeds with maximum weed control efficiency (88.1%). Application of imazethapyr alone at 40 g/ha applied at 3–4 leaf stage (around 20 DAS) significantly reduced the density and dry weight of broadleaved weeds but not effective significantly against grassy weeds. Yield attributes i.e pods/plant, seed and straw yields, net return and B: C ratio were also superior with imazethapyr + imazamox 40 g/ha applied at 3–4 leaf stage (around 20DAS).