Chandele, A.G.Kharbade Satappa B.2018-06-132018-06-131996http://krishikosh.egranth.ac.in/handle/1/5810052405The present studies were carried out to find out the relative bioefflcacy of different formulated products of Bacillus thurlnglensls varieties viz., kurstakl, thurlnglensls, kurstakl X alzwal and alzwal against Earlas vlttella (Fabricius) on okra under laboratory and field conditions during Kharlf 1994, Kharlf 1995 and Summer 1995 at Agril. Entomology Section, College of Agriculture, Pune. The observations on biology of the pest, LT50 and per cent fruit damage and yield of marketable fruits of okra were recorded. The B.t. products tested were Dipel 8 L, Delfin WG, Biolep WP, Bioasp WP, Halt WP formulations of B.t. var. kurstakl, Agree WP B.t. var. kurstakl X alzwal, Biotox WP B.t. var. thuringiensls and Centari WG B.t. var. aizwai. Studies carried out under laboratory condition revealed that the formulations of B.t. var. kurstakl viz., Dlpel 8 L (LT50 24.71 hrs.), Delfin WG (LT50 29.07 hrs.) and Halt WP (LT50 29.92 hrs.) were observed to be more effective followed by the formulations of B.t. var. thurlnglensls, Biotox WP (LT50 31.25 hrs.), B.t. var. kurstakl X aizwai Agree WP (LT50 37.06 hrs.), B.t. var. aizwai Centari WG (LT50 42.20 hrs.). The larval mortality starts from 12 hrs after the treatment and reached to its peak at 60 hrs after the treatment. The corrected mortality and LT50 value indicating similar trend of efficacy. Under field conditions, B.t. var. kurstakl was found to be more effective when per cent fruit damage and yield of marketable fruits of okrarbaken into consideration. While, B.t. var. thurlngien3ls was moderately effective followed by B.t. var. kurstaki X aizwai and B.t. var. aizwai. The average yield of marketable fruits of okra during the year 1994-1995 as influenced by different B.t. treatments ranged from 60 to 76.56 q/ha as against 35.15 to 49.15 q/ha in untreated plots. While, per cent fruit damage ranged from 11.90 to 24.90 per cent as against 42.14 per cent in untreated control. All B.t. treatments/observed to be significantly superior over control. The present findings are indicative for the incorporation of B. t..s in development of Integrated Pest Management for E. vittella.ennullThesis