Evaluation of acaricides and insecticides against the spidermite and aphid on bhendi

摘要

Okra, Abelmoschus esculentus L. (Moench) an important vegetable crop in tropics is ravaged by more than 30 insect pests at different growth stages. Among them, the carmine spider mite, Tetranychus cinnabarinus Boisd, often causes complete failure of the crop (Cherian, 1931). The attack by this mite results in yellowing, crumbling, curling and misting of leaves. The leaves are covered with heavy webs which adversely affect the photosynthetic activity of the leaves, eventually dry up and fall off (Singh and Singh, 1993). In severe cases, flowering and fruit formation are affected (Singh et at. 1991). Even malformation of fruits, leads to loss of its marketability. To control this pest, acaricides viz., dicofol, ethion and wettable sulphur have been recommended (Rai and Singh, 1996). The aphid, Aphis gossypii is also a serious pest occurring in the early stage of the okra crop, causing heavy yield loss. Some of the systemic insecticides are highly effective against aphid on bhendi (Sharma et at. 1996). To find out some alternative chemicals, carbosulfan 25 EC, Bifenthrin 10 percent WP, and a neem based product, Neemitaf were evaluated for their bioefficacy in field condition and the results are discussed in this paper.