Field efficacy of newer insecticides against sucking insect pests in castor

Abstract

Field experiments were conducted during 2014, 2015 and 2016 to evaluate the efficacy of four newer insecticides (clothianidin 50 WG @ 25 g a.i./ha, flonicamid 50 WG @ 50 g a.i./ha, acetamiprid 20 SP @ 20 g a.i./ha, thiamethoxam 25 WG @ 50 g a.i./ha) along with two conventional insecticides (profenofos 50 EC @ 250 g a.i./ ha and dimethoate 30 EC @ 250 g a.i./ha) against sucking insect pests viz., leafhopper (Empoasca flavescens) and thrips (Retithrips syriacus) in castor. Based on pooled analysis of three years data, per cent reduction of leafhopper was found to be higher in clothianidin (99.2% reduction over untreated control) followed by acetamiprid (97.6%) and dimethoate (97.2%). Clothianidin provided 95.1 per cent reduction in thrips population followed by dimethoate (89.4%) and acetamiprid (86.6%). Significantly highest seed yield was harvested from the clothianidin treated plots (1116 kg/ha) followed by profenofos (1017 kg/ha) and acetamiprid (1012 kg/ha), which were at par with each other, whereas the lowest yield was recorded in untreated control (729 kg/ha). The maximum net return (` 16068/ha) and benefit-cost ratio (1.70) was obtained with application of clothianidin followed by acetamiprid (` 13548/ha and 1.62) and profenofos (` 13443/ha and 1.61).