Bio-efficacy of new molecules chlorantraniliprole and emamectin benzoate against rice stem borers

The bio-efficacy of two new molecules rynaxypyr 0.4 G and 18.5 SC (chlorantaniliprole) and emamectin benzoate 5 SG at different doses against rice stem borers were studied in comparison with fipronil, carbofuran and profenophos on rice variety “Swarna” (MTU-7029) at the Central Research Station Farm, Orissa University of Agriculture and Technology, Bhubaneswar during wet season, 2012 and dry season, 2013 with recommended agronomic package of practices. The results revealed that rynaxypyr 0.4 G @ 50 g a.i. ha-1 to be the best treatment for the control of the pest by reducing the dead heart (80.21% and 87.48% during wet and dry seasons, respectively over control) and white ear head (72.56% and 86.16% reduction, respectively over control) with highest grain yield of 5.1 t ha-1 and 5.5 t ha-1 during wet season and dry season, respectively. Recommended insecticides like fipronil, profenophos and carbofuran were least effective in control of stem borer with lower grain yield. The highest C:B ratio (1:6.81) was due to rynaxypyr 0.4 G@ 40 g a.i. ha-1 during dry season, 2013 and second highest (1:5.80) during wet season, 2012.

Author : NY Chanu* and BK Sontakke