author(s)
Y Sai, M Sreekanth, DV Sairam Kumar and V Manoj Kumar

abstract
An experiment was conducted to study the morphological and biochemical factors of pigeonpea [Cajanus cajan (L.) Millsp.] associated with resistance to Helicoverpa armigera and Maruca vitrataa during Kharif 2014 at Regional Agricultural Research Station, Lam, Guntur, Andhra Pradesh, India. Among the morphological factors, trichome density on upper and lower surface of leaf showed significant correlation with correlation coefficient (r) being = -0.631 and -0.742, respectively with pod damage due to H. armigera and correlation coefficient (r) being -0.512 and -0.603 with pod damage due to M. vitrata, respectively. Thus, the genotypes having higher density of trichomes on leaves suffered less pod damage due to pod borers. Among the biochemical factors, sugars and proteins present in flowers showed significant correlation with correlation coefficient (r) being 0.610 and 0.679, respectively with pod damage due to H. armigera. Further, there exists a strong correlation between proteins, phenols and sugars with flowers with correlation coefficient (r) being 0.717, -0.702 and 0.772, respectively against pod damage due to M. vitrata. Similarly, phenols and sugars present in pod walls exhibit a strong correlation with correlation coefficient (r) being -0.672 and 0.642, respectively against pod damage due to M. vitrata. The sugars present seeds showed strong significant correlation with correlation coefficient (r) being 0.699 against pod damage due to M. vitrata. Thus, proteins and sugars present in flowers, pod walls and seeds showed positive correlation and phenols showed negative correlation against pod damage due to pod borers in pigeonpea, respectively.