Comparative Evaluation of Biopesticides for the Management of Leucinodes orbonalis Infesting Brinjal

Abstract

Brinjal shoot and fruit borer, Leucinodes orbonalis, is a major pest of brinjal that causes serious damage to shoots and fruits. This field study evaluated the relative efficacy of selected biopesticides and biorational insecticides against L. orbonalis during the Kharif season of 2023 at the College of Agriculture, Hassan. The experiment was laid out in a randomised block design with eight treatments and three replications. The treatments comprised Metarhizium rileyi, Beauveria bassiana, azadirachtin 1,500 ppm, Metarhizium anisopliae, azadirachtin 10,000 ppm, spinosad 45% SC, chlorantraniliprole 18.5% SC as the standard check, and an untreated control. Two sprays were applied: the first at the initiation of infestation and the second 15 days later. Shoot infestation was recorded 3, 7, and 14 days after each spray, whereas fruit infestation was recorded at harvest. Chlorantraniliprole recorded the lowest pooled shoot infestation (2.78%) and fruit infestation (17.26%). Among the tested biopesticide and biorational treatments, spinosad recorded the lowest pooled shoot infestation (3.72%) and fruit infestation (19.06%), followed by azadirachtin 10,000 ppm. Entomopathogenic fungi were less effective than spinosad and azadirachtin but performed better than the untreated control. The findings indicate that spinosad and azadirachtin may be useful components of an integrated management programme for L. orbonalis.