Bio-efficacy of insecticides against yellow stem borer (Scirpophaga incertulas Walker) in rice (O. sativa L.) ecosystem of Varanasi region

Abstract

An experimental trial was conducted during Kharif season of 2016-17 and 2017-18 at the Agriculture Research Farm, Institute of Agricultural Sciences, Banaras Hindu University, Varanasi to evaluate the bio-efficacy of newer insecticides against yellow stem borer. The stem borer infestation varied from 3.85 to 7.85 per cent. Among the various insecticidal field evaluations against yellow stem borer, flubendiamide 20% WG @ 25 g a.i./ha was found best effective treatment against yellow stem borer recording overall mean per cent dead heart (DH) of 3.91 followed by Chlorantraniliprole 18.5 % SC @ 30 g a.i./ha (4.23%), Lamda Cyhalothrin 5% EC @ 20 g a.i./ha (4.94%), Fipronil 5 % SC @ 50 g a../ha (5.24%) and Thiamethoxam 25% WG @ 25 g a.i./ha (5.73%) respectively during 2016-17. During 2017-18 again Flubendiamide 20% WG @ 25 g a.i./ha was found best effective recording overall mean per cent dead heart (DH) of 4.28 followed by Chlorantraniliprole 18.5 % SC @ 30 g a.i./ha (4.93%), Fipronil 5 % SC @ 50 g a../ha (5.42%), Lamda Cyhalothrin 5% EC @ 20 g a.i./ha (5.55%) and Thiamethoxam 25% WG @ 25 g a.i./ha (5.93%), respectively. The highest main grain yield 5.10 t/ha during 2016-17 and 4.77 t/ha during 2017-18 was recorded from the plots treated with Flubendiamide 20% WG @ 25 g a.i./ha. While the lowest mean grain yield 3.38 and 3.00 t/ha was harvested from the plots treated with Neem (Azadiractin 0.15 % EC) @ 4 ml/liter during Kharif 2016-17 and 2017-18, respectively.