Morpho physico-chemical components of resistance to pod borer, Helicoverpa armigera (Hübner) in pigeonpea [Cajanus cajan (L.) millspaugh]

The experiments were conducted at CCS HAU, Hisar (Haryana) to study the morpho physico-chemical components of resistance to pod borer, Helicoverpa armigera in pigeonpea with different sowing dates. In different four sowing dates, the minimum pod infestation (1.70%) was recorded in (D₄) 3^rd week of July sown crop, whereas, it was observed maximum (4.54%) in (D₂) 1^st week of July sown crop. In different pigeonpea varieties, the minimum mean pod infestation (2.45%) was recorded in AL-201, whereas, the maximum mean pod infestation (3.72%) was recorded in Pusa-992. The glandular (type A) and non-glandular (type B) trichomes on pods of top and middle canopy of the plant and pod wall thickness were associated with resistance to H. armigera, whereas, the non-glandular lengthy (type C) trichomes and pod length were associated with susceptibility to this insect. The expression of resistance to H. armigera was also associated with the high amount of fat, phenol and tannin content. Crude protein and total soluble sugar content were responsible for higher pod infestation.