Photosynthesis: A plant physiological parameter to evaluate the damage caused by American bollworm, Helicoverpa armigera (Hübner) in cotton cultivars

Plant morphology and physiological functions may alter with insect herbivory. The objectives of this study were to study Helicoverpa armigera (Hübner) herbivory and its effects on the photosynthetic rates of cotton cultivars. Cotton cultivars (transgenic and non transgenic) were sown in field. The laboratory reared American bollworms of same instar were allowed to feed on cotton cultivars to estimate the damage in terms of photosynthetic rates. A significant difference in photosynthetic rates of cotton cultivars was observed after 48 and 72 hours of H. armigera release. This study will be helpful in identifying how insect herbivory affects the nutritional and energy reserves of plants and will also aid in the Integrated Pest Management (IPM) tools to identify pest damage.