Identification of tolerant genotypes against pulse beetle as a source to reduce post harvest losses in pigeonpea [Cajanus cajan (L.) Millisp.]

The present study intends to screen 52 pigeonpea genotypes for bruchid infestation under controlled conditions using no-choice assay. The results revealed significant differences among the genotypes considering parameters like growth index (GI), egg numbers and adult emergence. The genotypes viz., ICP 89049, IPA 37 and Dholi dwarf DB had low average values for GI (0.45, 0.48 and 0.48 respectively), number of eggs after 20 days (14.5, 21.5 and 28), and adults emerged after 30 days of oviposition (9.0, 7.0 and 4.5, respectively) when compared to the genotypes Asha (higher GI: 1.10) and IPA 7-6 (having 98.0 eggs after 20 days of incubation). Concerning associations among different traits, the GI had significant positive correlations with number of eggs laid (0.484), and number of adults emerged at 15-30 days (0.638). The GI showed a negative relationship with proportion of seed coat (-0.162) and seed hardness (-0.197). The traits that are less preferred by the bruchids include hard seed with less seed diameter and high proportion of seed coat. The tolerant genotypes viz. ICP 89049, IPA 37 and Dholi dwarf DB identified here could be deployed in breeding programs for reducing post harvest losses in pigeonpea.