SCREENING OF BRINJAL (SOLANUM-MELONGENA) FOR RESISTANCE TO MAJOR INSECT PESTS

A field experiment was conducted during 1991-92 and 1992-93 in a farmer's field of Siliguri in the foot-hill (tarai) region to evaluate the relative degree of resistance offered by 41 cultivars of brinjal (Solanum melongena L.) to major insect pests. The pests studied were the brinjal shoot-and-fruitborer (Leucinodes orbonalis Guen.), cotton leaf hopper [Amrasca biguttula biguttula (Ishida)], cotton aphid (Aphis gossypii Glover) and the spotted leaf beetle (Epilachna vigintioctopunctata Fabr.). The experimental plots were left for natural infestation, and data on insect population and damages were recorded at 20-day intervals throughout the period of crop growth. Although the analysis of variance showed significant differences among the genotypes screened, no variety was found resistant to any of the 4 pests. However, the relative incidence of the pests showed that 'Nishchindipur Local', 'Muktajhuri', 'Shyamla Dhepa', 'Navkiran', 'Banaras Long Purple' and 'BB 1' were tolerant to the shootborer L. orbonalis, whereas 'Shyamla Dhepa', 'Kalo Dhepa' and 'Banaras Long Purple' were tolerant to the fruitborer L. orbonalis. 'Navkiran' showed tolerance whereas 'R 14' was highly susceptible to all the major pests of brinjal. Hence the varieties having tolerance or even multiple resistance, viz 'Shyamla Dhepa', 'Kalo Dhepa', 'Improved Muktakeshi', 'Banaras Long Purple' and 'BB1' could be used for incorporation in the breeding programme and integrated pest management.