Evaluation of integrated pest management module for insect pests of castor (Ricinus communis L.)

Abstract

A field experiment was conducted to evaluate integrated pest management (IPM) module in castor using threepopular cultivars(DCH-519, DCH-177, DCS-107) and compared with farmers' practice and untreated control. IPMmodule comprised of mechanical control of gregarious stages of tobacco caterpillar and older larvae of semilooper, economic threshold level based application of thiodicarb 75WP @ 375 g a.i./ha against tobacco caterpillar (at 25% foliage damage), indoxacarb 15.8EC @ 75 g a.i./ha against capsule borer (at 10% capsule damage) and dimethoate 30EC @ 250 g a.i./ha against leafhopper (at 10% hopper burn damage) superior in reducing the insect pest population over farmers' practice. In the IPM module, the mean population of semilooper, tobacco caterpillar, leafhopper and capsule borer damage was 0.3 larvae/plant, 0.8 larvae/plant, 16.2 leafhoppers/3 leaves/plant and 10.3% capsule damage as against 0.6 larvae/plant, 2.3 larvae/plant, 20.7 leafhoppers/3 leaves/plant and 16.5% capsule damage in farmers' practice, respectively. IPM module found safer to its larval parasitoid, Snellenius (Microplitis) maculipennis as compared to farmers' practice. The higher mean castor seed yield (1348 kg/ha) and avoidable yield loss (67.6%) was obtained from IPM module over farmers' practice with seed yield of 1008 kg/ha and avoidable yield loss of 55.5%. Further, higher net profit of ` 26889/ha and incremental cost-benefit ratio of 1:5.95 was recorded in IPM module as compared to ` 15584/ha and 1: 3.97 under farmers' practice.