Field efficacy of certain insecticides and biopesticides against maize stem borer, Chilo partellus infesting maize (Zea mays L.)

The maize stem borer, Chilo partellus (Swinhoe) is one of the destructive pests of maize crop. The management of C. partellus was done using different treatments under field conditions and experiment was laid-out in randomized block design with three replications during the rabi season of 2022-2023 and benefit cost ratios of all the treatments were also calculated. The activity of maize stem borer on maize commenced from 46^th standard week (3 week of November, 2022) and continued till the crop harvesting stage with maximum maize stem borer population (2.4 larva/plant) in the standard week (4 week of December, 2022) when the corresponding maximum (29.65 °C), minimum temperature (18.8 °C), relative humidity (80.85 %), and sunshine (6.87 h ) at 7 and 14 h. Total eight treatments viz., Chlorantraniliprole 18.5% SC 0.5ml ml/lit of water, Emamectin benzoate 5% SG 0.4 g/lit of water, Novaluron 10% EC 1.5 ml/lit of water, Spinosad 45% SC 0.5 ml/lit of water, Beauveria bassiana WP 5 g/lit of water, Nisco sixer plus 1ml/lit of water and Neem oil 5% @ 5 ml/lit of water and Untreated control were tested. The different insecticides and biopesticides treatments revealed that all the treatments were superior over control. Among the treatment Chlorantraniliprole 18.5% SC (0.66) which found most effective followed by Emamectin benzoate 5% SG (0.87) in comparison to control (6.02). The highest crop production (22.01 q/ha) was recorded Chlorantraniliprole 18.5% SC treated field with benefit-cost ratio of 1:2.60 followed by Emamectin benzoate 5% SG (21.09 q/ha) with 1:2.55 B:C ratio in comparison to control (9.5 q/ha) with 1:1.29 B:C ratio. Present study revealed that synthetic chemicals shows better results in combating to the pest infestation compare to the botanicals.