Srivastava, R.M.Kunwar, Roopam2021-09-302021-09-302021-09https://krishikosh.egranth.ac.in/handle/1/5810176466The current study was carried out at Vegetable Research Centre, GBPUA&T, Pantnagar, Uttarakhand during Rabi crop season of 2020-21. Seasonal incidence of sucking insect-pests, viz., aphid, leafhopper, thrips and whitefly were observed from 46th-05th SW (3rd week of December to 1st week of February). The peak activity of M. persicae and A. gossypii (10.56 and 8.97/3 compound leaves) was observed during 51st SW while the population of whitefly, leafhopper and thrips reached at peak on 49th SW with 13.81, 5.35, and 12.40 mean counts/3 compound leaves respectively. The correlation studies indicated a negative correlation of M. persicae and A. Gossypii population with temperature (maximum) (r= -0.77** and r= -0.75**), and a positive correlation (r= 0.67* and r= 0.66*) with relative humidity (minimum). Whitefly and leafhopper population displayed a positive correlation with maximum temperature (r=0.74**and r= 0.71**), and a negative correlation with maximum (r= -0.65* and r= -0.63*) and minimum relative humidity (r= -0.69* and r= -0.64*). The thrips population exhibited a positive correlation with maximum temperature (r= 0.70*) and a negative correlation with maximum (r= -0.64*) and minimum (r= -0.63*) relative humidity. The regression analysis indicated that the studied weather factors influenced population of aphid (M. persicae, R2= 0.79, and A. gossypii, R2= 0.75), whitefly (R2= 0.77), leafhopper (R2= 0.75), and thrips (R2= 0.74) on potato with reasonable accuracy. Comparative studies of different insecticide treatment for the management of aphids revealed that treatment T6 (First spray: Imidacloprid 17.8 SL @ 0.04% + Second spray: Thiamethoxam 25 WG @ 0.05%) was the most effective insecticide combination against aphids (76.84% reduction over control) with highest yield of 30.10 t/ha and maximum benefit cost ratio (1:2.14). However, in the case of whitefly T3 (First spray: Diafenthiuron 50 WP @ 0.10% + Second spray: Thiamethoxam 25 WG @ 0.05%) was found as the most effective treatment (72.93% reduction over control) with maximum yield of 29.06 t/ha and highest benefit cost ratio of 1:2.00. Different soil incorporated insecticides evaluated against major sucking pests (whiteflies, leafhoppers and aphids), revealed that higher dose of Fipronil 0.3 G @ 25 kg ha-1 (T4) was found to be more effective and superior in reducing infestation of these pests with a high per cent reduction 79.38%, 80.98%, and 78.68% respectively over control with highest yield of 31.48 t/ha and maximum benefit cost ratio of 1:2.27 and it can be used as an alternative for Phorate 10 G.EnglishThesis