INTEGRATED MANAGEMENT OF MOLE CRICKET ATTACKING POTATO IN EASTERN GANGETIC PLAINS WEST BENGAL

Abstract

In eastern gangetic plains of West Bengal, mole cricket, Gryllotalpa africana, P. de Beau. (Orthoptera : Gryllotalpidae) is one of the important soil pests of potato, causing 5-6% plant damage along with 10-15% tuber damage. With the objective of integrated management of mole cricket, four treatment schedules of different components were evaluated under field conditions at Hooghly (WB) during rabi seasons of 2001-02 to 2004-05. Potato cv. Kufri Chandramukhi was planted during end of November in the plots measuring 3 m x 2 m with 60 cm x 20 cm spacing. The four treatment schedules were replicated five times in randomized block design. Observation was recorded on the per cent plant damage at 7 days interval following the application of various treatments and the data regarding healthy and damaged tubers on number and weight basis were also taken at harvest. All the treatments proved statistically superior over control. The per cent plant damage was lower in T₂2 (i.e. treatment receiving phorate 10G @ 1.0 kg a.i./ha at planting, chlorpyriphos 20EC @ 0.5 kg a.i./ha at 45 DAP, cartap hydrochloride 50SP @ 1.0 kg a.i./ha at 60 DAP and imidacloprid 17.8SL @ 0.04 kg a.i./ha at 75 DAP) followed by T₄ (i.e. treatment receiving phorate 10G @ 1.0 kg a.i./ha at planting, chlorpyriphos 20EC @ 0.5 kg a.i./ha at 45 DAP, Bacillus thuringiensis var. Kurstaki 109 spore count/ml @ 750 g/ha at 60 DAP, imidacloprid 17.8SL @ 0.04 kg a.i./ha at 75 DAP and neem 5000 ppm @ 0.4% conc. at 90 DAP), T₃ (i.e. tuber treatment with Bt @ 750 g/ha, Bt @ 750 g/ha at 45 DAP, neem 5000 ppm @ 0.4% conc. at 65 DAP and repeat neem spray at 80 DAP). The treatment schedule containing only synthetic insecticides also gave more number of healthy tubers (11.64% more than control) as well as more healthy tuber yield (28.79% more than control). The net gain was found maximum in T₂ followed by T₄ and T₃, respectively. Therefore, it may be inferred that the treatment schedule consisting only biopesticides could not control the pest effectively whereas the treatment schedules containing insecticides alone or in combination with biopesticides are more effective against the pest on potato.