Abstract

An experiment on effect of weather parameters on activity of sapota bud borer, Anarsia achrasella Bradley on sapota was carried out under middle Gujarat conditions at Anand Agricultural University, Anand. The higher population (6.00 to 17.50 larvae /50 twigs) and bud damage (14.50 to 36.11%) of A. achrasella were found during January to May. The correlation between bright sunshine hours and larval population (r=0.500) as well as bud damage (r=0.559) was highly significant and positive. The morning relative humidity, evening relative humidity, mean relative humidity, evening vapour pressure, rainy days and rainfall were highly significant and negative with larval population of A. achrasella and its damage in sapota orchard. Mean temperature, morning vapour pressure, mean vapour pressure and wind speed had significant negative correlation with bud damage. Regression analysis of larval population indicated those bright sunshine hours, wind speed, mean temperature, evening vapour pressure and morning relative humidity, the partial regression coefficients were found significant except wind speed and coefficient of determination (R²) was 0.39. Whereas regression analysis of bud damage showed that wind speed, evening vapour pressure and morning relative humidity were non-significant, the partial regression coefficients were found significant and coefficient of determination (R²) was 0.45.

Key words: Weather parameters, Anarsia achrasella, activity, sapota.