Bio Efficacy and Economics of Systemic Insecticides against Whitefly in Potato

A field experiment was conducted at Potato Research Station, S. D. Agricultural University, Deesa during 2018-19 and 2019-20 for evaluation of efficacy of insecticides against whitefly in potato. The seven different treatments viz. T1: Control, T2: Seed treatment with imidacloprid (200 SL) @ 0.04% followed by foliar sprays of imidacloprid @60 gm a.i./ha at 85% emergence + second spray with thiamethoxam 25WG @100g a.i./ha, T3: Foliar spray of diafenthiuron 50WP 350 g a.i. at 85% emergence, T4: Foliar spray of diafenthiuron 50WP 350 g a.i. at 85% emergence followed by second spray of diafenthiuron  after 10 days, T5: Foliar spray of castor oil @0.05% at 85% emergence, T6: Foliar spray of diafenthiuron 50WP 350 g a.i. at 85% emergence  mixed with castor oil @0.05%, T7: Foliar spray of diafenthiuron 50WP 350 g a.i. at 85% emergence  mixed with castor oil @0.05%  by second spray with  diafenthiuron  after 10 days.  Based on pooled data of two years, the significantly highest per cent reduction (i.e. 68.57 %) after 2nd spray was recorded in T7 i.e. foliar spray of diafenthiuron 50WP 350 g a.i. at 85% emergence mixed with castor oil @0.05% by second spray with diafenthiuron after 10 days which was at par with T4 (Foliar spray of diafenthiuron 50WP 350 g a.i. at 85% emergence followed by second spray of diafenthiuron after 10 days). The tuber highest yield and benefit cost ratio were also recorded with T7.