Vegetos

Abstract

Crop loss estimation was done under artificial condition by releasing known number of Helicoverpa armigera larvae in each treatment. The experimentation was conducted during kharif season on CSH-16 hybrid. Each treatment included separately with known number of larvae viz., 0, 1, 2, 3, 4, 5, 6, 7 and 8. The stage of the larvae released was first instar during flowering, milk and both flowering and milk stages. Maximum grain yield of 101.50 g per earhead was recorded when single larvae per earhead was released and all other treatments differed significantly with each other. There was significant difference with respect to grain yield between flowering, milk and both flowering and milk stages which recorded 89.09, 91.39 and 68.39 g per earhead, respectively. Low grain yield per earhead was recorded when larvae were released at both stages i.e., flowering and milky stages as compared to larvae released once at each stage. Number of larvae released per earhead increased simultaneously reflected in reduction of grain yield.