Efficacy of Insecticides against Major Insect Pests of Okra (Abelmoschus esculentus L.): Impact on Pest Populations, Natural Enemies, Yield and Economic
Jyotirmayee Dalei
Department of Entomology, College of Agriculture, Odisha University of Agriculture and Technology, Bhubaneswar-751003, India.
Abhijit Kar
*
Department of Entomology, College of Agriculture, Odisha University of Agriculture and Technology, Bhubaneswar-751003, India.
Sashanka Sekhar Dash
Department of Entomology, College of Agriculture, Odisha University of Agriculture and Technology, Bhubaneswar-751003, India.
*Author to whom correspondence should be addressed.
Abstract
Aims: The present study evaluates the efficacy of eight insecticides against major okra pests (jassids, whiteflies, and shoot and fruit borer), their safety to beneficial coccinellid beetles, and their economic viability based on yield performance and cost-benefit analysis.
Study Design: Randomized block design with three replications.
Place and Duration of Study: Central Research Station, Odisha University of Agriculture and Technology, Bhubaneswar, during the summer seasons of 2019-20 and 2020-21.
Methodology: Eight insecticides, including flupyradifurone (250 g a.i./ha), diafenthiuron (300 g a.i./ha), and emamectin benzoate (7 g a.i./ha), were applied as foliar sprays at 30 and 45 days after sowing (DAS). Pest populations, fruit damage, coccinellid counts, yield, and incremental cost-benefit ratio (ICBR) were assessed. Data were arcsine-transformed and analyzed using ANOVA.
Results: Flupyradifurone reduced jassid populations by 79.84% (2.47/plant, P = 0.05), diafenthiuron whitefly populations by 79.39% (1.20/plant, P = 0.05), and emamectin benzoate fruit borer damage by 82.35% (4.12% by number, P = 0.05). Emamectin benzoate achieved the highest yield 7.54 t/ha (89.92% increase, P = 0.05) with an ICBR of 1:12.44 (Rs 66,090/ha). Emamectin benzoate, clothianidin, spinetoram, and flupyradifurone preserved coccinellid populations (3.89–4.25/5 leaves, P > 0.05 vs. control).
Conclusion: Flupyradifurone, diafenthiuron, and emamectin benzoate were effective, ecologically safe, and economically viable pest management for okra, supporting integrated pest management strategies. Flupyradifurone, diafenthiuron, and emamectin benzoate were effective, ecologically safe, and economically viable for okra pest management, supporting integrated pest management strategies.
Keywords: Okra, novel insecticides, jassids, whiteflies, shoot and fruit borer, incremental cost-benefit ratio