Seasonal Activity of Aproaerema modicella in Groundnut in Saurashtra Region of Gujarat
Field studies were conducted for twelve years (1994 to 2005) to develop and validate the forecasting model on the activity of groundnut leaf minor (GLM) during different seasons such as summer, kharif and rabi in relation to weather parameters. The leaf miner incidence based on male moth catches in pheromone traps was high during the rabi crop season and reached peak from November to January. Correlation studies between weather parameters and male moth catches of GLM revealed significant positive correlation between maximum temperature and bright sun shine hours while minimum temperature, morning and evening relative humidity and rainfall showed significant negative correlation during kharif. In rabi, maximum temperature and bright sun shine hours had significant positive correlation while minimum temperature had significant negative correlation. During summer, maximum and minimum temperature and soil temperature at 10 and 20 cm depth and bright sun shine hours had significant negative correlation whereas, the remaining parameters failed to show any significant correlation with the male moth catches. The predicted values of occurrence of GLM using regression equation showed minimum deviation from the actual values of GLM population during certain months, indicating the feasibility of predicting the population occurrence using the prevailing weather factors.