Eco-Friendly Botanical Seed Treatments for the Management of Storage Insect Pests and Preservation of Seed Quality in Pearl Millet (Pennisetum glaucum L.)

Abstract

The present study evaluated the efficacy of botanically derived seed treatments for managing insect pests and maintaining the quality of stored pearl millet [Pennisetum glaucum (L.)] under ambient conditions. Certified seeds of the variety “Dhanshakti” were treated with eight botanicals—eucalyptus leaves, garlic powder, marigold leaves, turmeric powder, lemongrass, citrus leaves, garden mint leaves, and ginger leaves alongside an untreated control. The seeds were stored for four months, and observations were recorded on seed damage, weight loss, and germination percentage. Among the treatments, eucalyptus leaves were most effective, reducing seed damage (4.58%) and weight loss (3.44%) while maintaining the highest germination (88.9%). Garlic powder ranked second (seed damage 5.44%, weight loss 4.08%, germination 85.7%), followed by marigold leaves (6.34% damage, 83.1% germination). Turmeric powder, lemongrass, and citrus leaves showed moderate protection, sustaining germination above 79%. Garden mint and ginger leaves were less effective, with ginger leaves showing the highest damage (7.98%) and lower germination (76.5%) among the botanicals. The untreated control exhibited maximum damage (11.18%), weight loss (8.38%), and the lowest germination (69.7%). Their action is mediated by diverse bioactive compounds: eucalyptol in eucalyptus acts as a fumigant and contact insecticide, allicin in garlic interferes with enzymatic and microbial activity, and thiophenes in marigold or curcuminoids in turmeric disrupt insect development and feeding. These mechanisms underline the eco-friendly, sustainable, and farmer-compatible nature of botanical treatments, making them vital tools for reducing post-harvest losses and enhancing food security in millet-growing regions.