Varietal preference of pulse beetle, Callosobruchus maculatus (F.) in greengram

Abstract

Eighty five greengram accessions were evaluated against the pulse beetle, Callosobruchus maculatus (F.) to find the sources of resistance under laboratory condition. Accessions which exhibited lesser growth index (GI) during the preliminary ‘free choice’ test were further subjected to ‘force choice’ test for confirmation of resistance. Though, no accession was found immune to infestation, yet showed significant differences in terms of oviposition, developmental period, adult emergence and seed weight loss. Three accessions viz, KM-12-10, KM-11-32 and KM-11-10 revealed lesser adult emergence (21.34, 30.64 and 34.92%, respectively), prolonged developmental period (32.21, 31.82 and 34.59 days, respectively) and lesser index of suitability (0.041, 0.047 and 0.049, respectively) as compared to the highly susceptible M1319B, which exhibited 84.05% survival, developmental period of 23.75 days, and index of suitability 0.081. Correlation between GI and other growth parameters on the accessions indicated that the GI had negative relationship with developmental period (-0.0987) and significant positive relationship with adult emergence (0.985) and weight loss (0.959). Hence, these accessions might be effectively used as promising donors for developing resistant varieties, and for reducing post harvest losses.