Field studies were conducted for seven years (1999 to 2005) to study the effect of abiotic parameters on the activity of Aphis craccivora Koch using multiple regression and correlation analyses. A. craccivora was present through out the year on groundnut and widely fluctuated from season to season. However, the intensity was greater during rabi followed by kharif and summer. Correlation studies revealed that morning and evening relative humidity were significantly positive while minimum temperature showed significant negative correlation during rabi. In kharif, minimum temperature and rainfall had significant negative correlation. During summer, maximum and minimum temperatures, morning and evening relative humidity and wind velocity showed significant negative correlation whereas, remaining parameters fail to show any significant correlation with aphid population. The coefficient of determination (R2) between weather parameters and aphid population during rabi, summer and kharif seasons was 15.47%, 44.58% and 12.70% respectively over seven years of study, suggesting the importance of these parameters in influencing the abundance of A. craccivora.
Groundnut, Aphis craccivora, weather factors, correlation, regression
