Population dynamics of gram pod borer (Helicoverpa armigera) in relation to weather factors under Tamil Nadu condition

Pheromone technology possesses enormous potential as one of the tools in IPM. Population dynamics of gram pod borer, Helicoverpa armigera was studied using sex pheromone lures developed at Tamil Nadu Agricultural University, Coimbatore. Result showed that the peak emergence of H. armigera adults during 51st (8.25 moths/trap/week) and 52nd (8.00 moths) standard weeks followed by 1st standard week (7.25 moths). The correlation and regression analysis indicated that the emergence of H. armigera adults had a significant negative association with minimum temperature while, other parameters (maximum temperature, relative humidity, rainfall and rainy days) had no influence on H. armigera activity. The simple liner regression analysis showed a R2 value of 0.528 revealing that 52.8% of the variation in the trap catches of H. armigera was influenced by minimum temperature alone.