Vol. 11, Special Issue 9 (2022)

Investigations on “Seasonal incidence of shoot fly, Atherigona approximata (Malloch) and stem borer, Chilo partellus (Swinhoe) infesting pearl millet” were carried out under field condition during Kharif - 2021 at the Instructional Farm, College of Agriculture, Junagadh Agriculture University, Junagadh, Gujarat. Result showed that the infestation of shoot fly started in 33^th standard meteorological week when temperature ranged between 32.9 ℃ (maximum) and 24.3 ℃ (minimum), average relative humidity 70.5 per cent, total rainfall 8.1 mm and 3.5 sunshine hours. The shoot fly infestation increased gradually to maximum (20.67%) on 37th standard meteorological week at 29.1 ℃ maximum temperature and 24.5 ℃ minimum temperature, 92 per cent average relative humidity, 0.9 sunshine hour and 393.4 mm total rainfall. Thereafter, the infestation of shoot fly declined. The infestation of stem borer started in 33th standard meteorological week when temperature ranged between 32.9 ℃ (maximum) and 24.3 ℃ (minimum), average relative humidity 70.5 per cent, total rainfall 8.1 mm and 3.5 sunshine hours. The stem borer infestation increased gradually and reached to maximum (16.67%) on 36th standard meteorological week at 30.1 ℃ maximum temperature and 23.7 ℃ minimum temperature, 88.5 per cent average relative humidity, 179.3 mm total rainfall and 1.4 sunshine hours. Thereafter, the infestation of stem borer declined

The relationship between shootfly and weather factor indicate a highly significant negative correlation with maximum temperature (r= -0.877**) and a non-significant positive correlation with minimum temperature (r= 0.375), while a negative correlation with bright sunshine hours (-0.522) and highly significant positive correlation with morning relative humidity (r=0.802**), evening relative humidity (r= 0.814**) and total rain fall (r= 0.817**). In case of stem borer, highly significant negative correlation with maximum temperature (r= -0.804**), while positive correlation with morning relative humidity (r=0.749**), evening relative humidity (r=0.764**) and non-significant positive correlation with minimum temperature (r=0.319), while negative correlation with bright sunshine hours (r= -0.421) and significant positive correlation with total rainfall (r= 0.681*).