Studies on the Seasonal Incidence and Bio Efficacy of Newer Insecticides Against Onion Thrips Thrips tabaci L

Abstract

The present investigation entitled Studies on the seasonal incidence and Bio-efficacy of newlinenewer insecticides against onion thrips (Thrips tabaci L.) was conducted at Vegetable newlineresearch farm, Institute of agricultural science, Banaras Hindu University during the rabi newlineseason of 2021-2022. newlineThe experiment was laid out in Randomized block design with seven treatments and newlinethree replications. The treatments consisted of sixchemical insecticides (cyantraniliprole newline10.26% OD at 75,60,90,45 g.a.i/ha, lambda-cyhalothrin 5% EC, and fipronil 80% WG) and a newlinecontrol. All the recommended agronomical practices were followed to raise onion crop newline(variety Agri-found red). The seasonal incidence of T. tabaci was studied by recording the newlinethrips population per plant at weekly interval after transplantation till the harvest of the crop. newlineThe insect incidence was correlated with weather factors to understand the population newlinedynamics.The efficacy of different insecticide against T. tabaci was evaluated using different newlinetreatment. Foliar application of pesticides on the crop was carried out two times at interval of newline14 days. First pesticide application was done 30 days after transplanting. The sprayer was newlinecalibrated before use to regulate the quantity of spray solution as per requirement. newlineObservations on thrips were recorded before and after each spray. there were seven newlinementioned treatments replicated thrice.Observations were taken one day before treatments newline(pre-treatment) onthe 1st, 5th, 10thand 14th days after each spray.The sampling unit for newlinerecording the thrips population was innermost leaves of per plant and 5 plant selected from newlineeach plot and replications . Mean thrips population under different treatments was subjected newlineto the analysis of variance at 5% level of significance.The first appearance (4.64 thrips/plant) newlineof T. tabaci on the onion crop was observed during 50th standard metrological week. During newlinethis period maximum and minimum temperature was 24.6 and 8.60 C, respectively. The newlinerelative humidity was 94% (morning) and 44%(evening). Th