Life table studies and management of diamondback moth plutella xylostella l through organic approach in cabbage

Abstract

Investigations on the topic were undertaken during 2005 to 2007 at University of newlineAgricultural Sciences, Dharwad and Garag village. Eight life tables of Plutella xylostella have newlinebeen constructed for the first time in Dharwad region (four generations in rainy season and newlinefour in cold season). Only two important parasitoids were recorded on P. xylostella viz., the newlinelarval parasitoid, Cotesia plutellae and the larval-pupal parasitoid Tetrastichus sokolowskii newlinewhich caused 18-44 per cent and 4-48 per cent parasitization of larval period 2 and pupae, newlinerespectively. These were the major key mortality factors. The incidence of C. plutellae was newlinemore in rainy season while, in winter season, T. sokolowskii was predominant. newlineSoil application of neem cake at 500 kg/ha followed by sprays of vermiwash, garlic newlinechilli kerosene extract + cow urine, NSKE 5 per cent and Neemazol at 10 days interval was newlinecomparable to the standard check, 100 per cent RDF+RPP in reducing the pest population newlineand recording high yield. newlineAmong different insecticides tested, spinosad (2.5 SC) at 15 g a.i./ha, emamectin newlinebenzoate (5 SG) at 7.5 g a.i/ha, indoxacarb (14.5 SC) at 35 g a.i/ha proved significantly newlinesuperior in reducing the larval population of P. xylostella, Spodoptera litura and Crocidolomia newlinebinotalis through out the crop period. Spinsoad proved to be highly cost effective (IBCR newline13.71). Among the tested chemicals dipel, novaluron, spinosad and emamectin benzoate in newlinethe mentioned order were found to be safe to the parasitoid. newlineAmong IPM modules evaluated, Adoptable module comprising of mustard trap crop, newlineapplication of neem cake at 500 kg/ha + 50 per cent RDF super imposed with sprays of Bt, newlinespinosad and emamectin benzoate offered good protection against the defoliators and newlineproved cost effective. This was followed by IIHR module. All IPM modules supported good newlineactivity of the parasitoid in the crop ecosystem compared to RPP. newline