Management of onion thrips by sequential strategy

Abstract

Field experiments were carried out during rabi season for three years of (2016-17, 2017-18 and 2018-19) for the management of onion thrips by sequential strategy. In the sequential strategy the insecticides consists of dimethoate 30 EC @ 200, lambda-cyhalothrin 5 EC @ 15 and quinalphos 25 EC @ 300 g a.i./ha; bipesticide: Metarhizium anisopliae 1.15 wp @ 5 g and botanical: NSE 5% and these were tested alternatively for control of onion thrips with untreated control. Among the sequential strategy, lambda-cyhalothrin 5 EC @ 15 g a.i./ha, followed by Metarhizium anisopliae 1.15 wp @ 5 g/l. followed by NSE 5% found most effective for control of thrips of onion at 3rd, 7th and 14th days after spray and this strategy recorded av. survival of thrips in the range 6.67-16.67 thrips/plant as against 28.67-31.33 thrips/plant in untreated control showing 1.2 rating of white patches on leaves. There was remarkable impact of this sequential strategy in on the yield of onion i.e. 261.73 q/ha marketable onion bulbs as against 160.65 q/ha in untreated control with ICBR ratio 1:17.38 and B:C ratio 1:1.59.