Sequential application of insecticides for management of leaf eating caterpillar, Spodoptera litura (Fabricius) (Lepidoptera: Noctuidae) in bidi tobacco nursery

Abstract

An experiment was carried out for two years (2017-18 and 2018-19) in randomized block design at Bidi Tobacco Research Station, Anand Agricultural University, Anand, Gujarat (India) to evaluate, the sequential application of insecticides for management oh leaf eating caterpillar, S. litura. In tobacco, nursery, use of neem seed kerne extract (NSKE) (500 g 10 L^-1 water) at the time of 30-35 days after seeding (DAS) followed by any of the recommended insecticide i.e: chioipyrifos 50 % + cypermethrin 5 % EC at 0.055 % (10 mL 10 L^-1 water, 275 g a.i/ha) or emamectin benzoate 5 % SG at 0.0025 % (5g 10 L^-1 water, 12.5 g a.i./ha) or chlorpyrifos 20% EC at 0.04 % (20 mL 10 L^-1 water, 200 g a.i/ha) or quinalphos 25 % EC at 0.05% (20 mL 10 L^-1 water, 250 g a.i/ha) 45 DAS, for effective and economical management of leaf eating caterpillar, S. litura. In an experiment in laboratory with same insecticides used for field experiment  were evaluated in completely randomized design for relative efficacy in order of the persistent toxicity. The-highest toxicity up to ten days was registered in cholrpyiiphos 50% + cybernethrin5% EC  followed by emamectin benzoate 5% SG, quinalphos 25% EC and chlorpyrifos 20% EC. The NSKE @ 5%  registered least persistence toxicity.