Relationship of physico-morphic characters of Okra cultivars with their resistance to Helicoverpa armigera

Abstract

Resistance to plants is often attributed to physical, morphological, physiological, biochemical, molecular and genetic characteristics of the plants. As the information about the relationship between physico-morphic characteristics of commercially grown okra cultivars and resistance or susceptibility to Helicoverpa armigera is lacking, therefore, in the present study relationship between physico-morphic characteristics and resistance or susceptibility of okra cultivars to H. armigera was evaluated. The heights and stem girths of comparatively resistant varieties were statistically greater as compared to intermediate resistant and comparatively susceptible varieties. Contrarily, hair densities on leaf midrib and leaf lamina were comparatively less in case of comparatively resistant varieties as compared to intermediate resistant and comparatively susceptible varieties. With one exception in each category, no significant differences were observed regarding area, moisture, thickness of leaves and fruit length of okra varieties. The leaf area was slightly greater in comparatively resistant varieties. Similarly, fruit was found to be significantly more in case of comparatively resistant varieties as compared to intermediate resistant and comparatively susceptible varieties. It was also observed that fruit and shoot infestation was the maximum on comparatively susceptible cultivars while infestation was significantly lower on comparatively resistant cultivars. Similarly, the pest produced significantly more eggs and larvae on comparatively susceptible cultivars as compared to comparatively resistant ones. As comparatively resistant okra varieties viz. Bhindi Punjab Selection, Arka Anamika and Bhindi Sabazpari suffered less damage and yielded more and are therefore, recommended for cultivation to avoid damage by Helicoverpa armigera.