Abstract. The noctuid, Helicoverpa armigera, is the most damaging pest of chickpea worldwide, and plant resistance is an important component for managing this pest. To develop cultivars with resistance to insects, it is important to understand the role of different components associated with resistance to insects. Therefore, we characterized a diverse array of chickpea genotypes and for organic acid profiles in the leaf exudates that are associated with resistance to H. armigera. Chickpea leaf exudates contained five major organic acids, which were identified as malic acid, oxalic acid, acetic acid, citric acid, and fumaric acid. The high performance liquid chromatography (HPLC) profiles of the leaf exudates of nine chickpea genotypes showed that amounts of malic acid were 2 negatively correlated with leaf feeding by H. armigera larvae at flowering and maturity, and with pod damage. Oxalic acid showed a negative association with leaf damage in detached leaf assay, while the amounts of acetic acid were negatively correlation with larval weight, and damage rating at flowering and maturity. Citric acid levels were negatively associated with damage rating at flowering. Implications of using HPLC profiles of organic acid leaf exudates to breed for resistance to H. armigera have been discussed.

Host-plant resistance is one of the major components of integrated pest management programmes against the noctuid pod borer Helicoverpa armigera (Hü bner) in chickpea. Survival and development of H. armigera on nine chickpea genotypes were compared using two food substrates, namely fresh leaves and pods, and artificial diets containing lyophilized leaf or pod powder of the same genotypes. Among the genotypes used, six showed different levels of resistance to H. armigera, while three were used as susceptible checks. Using leaves and pods, five of the resistant genotypes yielded lower larval weights compared to one of the susceptible checks used. Significant differences between four of the resistant and two of the susceptible genotypes were also observed when using artificial diets containing leaf or pod powder, but the rankings were different from that on the fresh leaves and pods. On both substrates, four resistant genotypes resulted in lower larval survival, pupation, adult emergence and fecundity when compared to one of the susceptible checks. A similar trend was also observed for larval survival and development when using F 1 hybrids based on four of the resistant genotypes. Survival and development of H. armigera on the two food substrates, fresh leaves and pods and artificial diets with lyophilized leaf or pod powder, were highly correlated, suggesting that incorporation of lyophilized leaves or pods into the artificial diet can be used to assess antibiosis to H. armigera in chickpea.

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