Effective weed management in clusterbean (Cyamopsis tetragonoloba) through post-emergence herbicide

Abstract

A field experiment was conducted at the Research Farm of Agricultural Research Station, Swami Keshwanand Rajasthan Agricultural University, Bikaner during the rainy (kharif) seasons of 2012, 2013 and 2014 to test the effi- cacy of different weed control measures against weeds in clusterbean [Cyamopsis tetragonoloba (L.) Taub.]. The experiment comprising seven weed control 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 days after sowing (DAS) and weedy check was laid out in a randomized block design with four replications. Amongst the herbicidal treatments, post-emergence application of imazethapyr + imazamox 40 g/ha applied at 34-leaf stage resulted in the lowest weed density and dry weight of both grassy and broad-leaf weeds. Application of imazethapyr alone at 40 g/ha applied at 34-leaf stage significantly reduced the density and dry weight of broad-leaf weeds, but it was not effective against grassy weeds. Pods/plant and seed and straw yields, net returns and benefit: cost ratio were also superior with imazethapyr + imazamox 40 g/ha com- pared to the other treatments.