Seasonal Incidence and Efficacy of Bio-rational Insecticides Against Major Insect Pests of Potato Crop

Abstract

An investigation to study, The major insect pest were observed attacking potato variety Kufri Bahar were whitefly (Bemisia tabaci), green peach aphid (Myzus persicae) and potato leafhopper (Empoasca fabae). The peak activity of aphid (13.89 aphid/5 plants) was recording during 4th week of January (3rd meteorological standard week), the highest peak of whitefly incidence (15.67 whitefly/5 plants) was observed during last week of November (47th meteorological standard week) and the peak activity leafhopper was observed during first week of December (49th meteorological standard week) and highest population (10.6 leafhopper/5 plants), respectively. The aphid population showed a significant negative correlation with maximum temperature (Tmax) r= -0.567, p<0.05, minimum temperature (Tmin) r= -0.648, p<0.01 and with mean temperature (Tmean) r= -501, p<0.05. The white fly population showed a signification positive correlation with maximum temperature (Tmax) r= 0.654, p<0.01 and mean temperature (Tmean) r= 0.678, p<0.01 and minimum temperature (Tmin) r= 0.579, p<0.01. Whereas a significantly negative correlation was observed with minimum relative humidity (RHmin r= 0.656, p<0.01 and mean relative humidity (RHmean) r= 0.686, p<0.01. The leaf hopper showed a significant negative correlation with minimum temperature (r= 0.583, p<0.05) and mean relative humidity (r= 0.485, p<0.05). Among the insecticides tested during present study, Thiamethoxam 25% WG @150 gm a.i/ha (T1) was found most effective and economical against sucking pests with maximum tuber yield of 294.45 q/ha and of 1:6:61 benefit cost ratio. Thus the use of Thiamethoxam 25% WG @150 gm a.i/ha can be considered as an effective insecticide for the management of sucking pests on potato crop.