Biopesticides for integrated pest management in bitter gourd (Momordica charantia L.)

Abstract

A field study was undertaken at the College of Horticulture, Vellanikkara during 1998-99 to compare the efficacy of two chemical insecticides viz., acephate, carbofuran, two biopesticides based on B. thuringiensis and B. bassiana and their combinations against the major pests of bitter gourd. Carbofuran was applied as granules at seeding, while the other treatments were applied as spray at fortnightly intervals from 35 DAS. It was observed from the study that application of acephate at 0.1 per cent was the most effective insecticide against sap feeders viz., leaf hopper and aphids. The combined application of B. thuringiensis or B. bassiana with acephate 0.05 per cent was also found effective. In controlling hadda beetle also, acephate at 0.1 per cent gave consistently good results. Gallfly infestation was minimum in acephate 0.1 per cent treated plots followed by B. thuringiensis + acephate 0.05 per cent sprayed plots. In the case offruitfly, B. bassiana + acephate 0.05 per cent registered the lowest infestation. The borer infestation was less in B. thuringiensis + acephate 0.05 per cent sprayed plots. This treatment also recorded the highest marketable yield (7573 kg ha") with the highest net profit of Rs. 25,344 ha-I and benefit cost ratio of 3.71 : 1. Studies on the residues of carbofuran by high performance liquid chromatography revealed that application of carbofuran either at 0.6 or 1.2 kg a.i.ha' at seeding resulted in no detectable terminal residue in bitter gourd fruits.