Dose-dependent efficacy of noni (Morinda citrifolia L.) leaf powder as a botanical bioinsecticide against Callosobruchus analis F. (Coleoptera: Bruchidae) in stored black soybean seeds

Abstract

Abstract Stored black soybean seeds (Glycine max L. Merr. cv. Detam-1) are highly susceptible to infestation by the bruchid Callosobruchus analis F., which reduces seed quantity and physiological quality during storage. This study evaluated the dose-dependent efficacy of noni (Morinda citrifolia L.) leaf powder as a botanical bioinsecticide for suppressing C. analis F. populations and preserving seed viability. A Completely Randomized Design was applied with six dosage levels (0, 2.5, 5.0, 7.5, 10.0, and 12.5 g of noni leaf powder per 100 g of seeds) and four replications, conducted at the Faculty of Agriculture, Winaya Mukti University, Sumedang, Indonesia, from April to June 2024. Insect mortality, egg, larval, and imago development, and seed quality parameters were assessed across treatments. Results showed a clear dose-dependent response, with increasing noni leaf powder concentration progressively enhancing mortality and suppressing egg, larval, and imago development; 7.5 g per 100 g of seeds was identified as the most effective threshold, achieving high insect suppression while maintaining seed physiological quality. Benchmarked on a dose-normalized basis against moringa and bintaro leaf powders previously evaluated by this research group, noni leaf powder showed intermediate dose-efficiency for reducing seed damage and weight loss. These findings support noni leaf powder as an eco-friendly, low-cost botanical bioinsecticide for integrated pest management in stored black soybean seeds, and contribute comparative, evidence-based guidance for selecting dose-efficient botanical options for postharvest storage.