Influence of intercrops on incidence of major pests of brinjal and their natural enemies

Among thirteen intercrops tried with brinjal intercropped with cluster bean (4:1) was cost effective which recorded the lowest shoot damage (115%) and fruit damage on number and weight basis by Leucinodes orbonalis (17.0 & 17.3%, respectively) and the lowest mean population of Coccidohystrix insolitus (41 nos/3 leaves) and Aphis gossypii (26.6 nos/3 leaves). No incidence of Henosepilachna vigintioctopunctata, Myllocerus spp., Amarasca devastans and Bemisia tabaci was noticed in brinjal intercropped with cluster bean. The population of natural enemies, coccinellids, syrphids and spiders were high in brinjal intercropped with cluster bean, recording 4.3, 3.1 and 1.9 nos/plant, as compared to brinjal as a pure crop. The highest cost benefit ratio of 1:2.70 was recorded in brinjal + cluster bean intercropping system while it was 1:1.62 in brinjal, as a pure crop.