Paper short abstract:

Satisfactory white fly control (> 50% mortality) in ladysfinger field was achieved with extract of Polygonum plants and spinosad. Polygonum was effective achieving more than 60 % mortality at 3 and 7 days after spraying. Bio-pesticides, safer to environment can be incorporated in organic farming.

Paper long abstract:

Ladysfinger (Abelmoschus esculentus L.) (Moench) is an annual vegetable crop grown in tropical and sub-tropical areas of the globe. The crop is susceptible to various pests of which white fly (Bemisia tabaci Genn.) causes heavy damage. It is very difficult to control this pest because the fruit is consumed after little cooking. This practice could lead to human health hazards arising from toxic residues in the fruit. This field study evaluated the efficacy of extracts from plants such as Polygonum hydropiper L. and Pongamia pinnata L., microbial insecticides like spinosad 45 SC (Saccharopolyspora spinosa Mertz & Yao) and Beauveria bassiana against B. tabaci infesting ladysfinger during post-kharif season. Methanol was used as solvent for extract. The plant parts are used in different ways for pest control in tribal areas under the sub-Himalayan region of north-east India. Imidacloprid 17.8% SL was used as check. Four sprays at 12-day intervals were made, starting with the initiation of infestation. Total white fly numbers per leaf were counted at 3, 7 and 11 days after treatment (DAT). Satisfactory white fly control (> 50% population suppression) was achieved with extract of Polygonum plants (5% concentration) and spinosad. The Polygonum extract was very effective, achieving more than 60 % mortality at 3 and 7 days after spraying. Plant extracts and microbial insecticides are biopesticides having less or no hazardous effects on human health and environment. Thus they can be incorporated in organic farming in vegetable cultivation.

Key words: Bio-pesticides, vegetables IPM, organic farming