Efficacy of Tank-Mix Herbicide and Insecticide Combinations for Management of Weed and Pests in Soybean [Glycine max (L.) Merrill.]

In India, soybean (Glycine max) is mainly grown as rainfed crop. The higher incidence of weed and pests during growth period are one of the important menaces in getting higher yield of this crop. A field experiment was conducted during 2013-2014 and 2014-2015 on vertisol soil at Agharkar Research Institute, Pune (MS), India, to evaluate bio-efficacy of compatible tank-mix combinations of herbicide and insecticides to manage the weed and insect-pests in soybean. Tank-mix application of quinalphos and imazethapyr (68.17 m^-2) resulted in significantly lowest weed density followed by imazethapyr (69.33 m^-2) at 30 Days after Sowing (DAS). At 45 DAS imazethapyr (26 m^-2) recorded significantly lowest weed density, whereas it was non-significantly different due to various treatments at 60 DAS. Sole application of imazethapyr and in combination with Rynaxypyr recorded lowest weed dry matter at 30, 45, and 60 DAS. Application of Rynaxypyr+imazethapyr at 30 DAS (67.36%) and at 60 DAS (85.52%) and sole imazethapyr at 45 DAS (81.66%) recorded higher weed control efficiency than the rest of the treatments. Number of leaf roller and tobacco caterpillar larvae per meter row length (mrl^-1) at seven days after treatment was significantly less in treatments involving insecticides. Visual defoliation score was significantly less in treatments involving insecticides than weedy check and sole herbicide.