Evaluation of some neem-based botanicals on the biology and management of Maize weevil (Sitophilus zeamais Motschulsky) on Maize grains under Laboratory condition
DOI:
https://doi.org/10.71464/rea5hv44Keywords:
Maize weevil, neem botanicals, stored maize, botanical insecticides, varietal resistanceAbstract
Post-harvest losses caused by maize weevil (Sitophilus zeamais) constitute major constraint to maize storage in tropical regions. This study evaluated the biology and management of S. zeamais using neem-based products on three maize varieties under laboratory storage conditions, between March and April 2025. Five neem-derived treatments were tested: neem seed powder, neem bark powder, neem root powder, neem leaf powder, and neem wood ash, each applied at five dosage levels (1–5 g per 20 g maize grains). Permethrin served as a synthetic insecticide standard, while untreated grains served as control. The experiment was arranged in a completely randomized design with three replications. Parameters evaluated included adult mortality, fecundity, adult emergence, seed perforation, percentage seed damage, and grain weight loss. Results showed that neem seed powder produced highest adult mortality, comparable to permethrin, particularly at 3–5 g per 20 g of maize grains. Neem bark powder and neem root powder also demonstrated significant insecticidal activity at higher dosages, whereas neem leaf powder exhibited moderate efficacy. Neem wood ash was largely ineffective at lower concentrations and performed similarly to untreated control. Neem seed powder significantly suppressed oviposition and adult emergence, resulting in minimal seed perforation, low grain damage, and negligible weight loss. Among maize varieties tested, Zakka showed relatively higher resistance to infestation, whereas Sammaz 27 and Sammaz 60 were more susceptible under untreated conditions. However, neem treatments significantly reduced infestation across all varieties. The study demonstrates potential of neem botanicals, particularly neem seed powder, as eco-friendly, affordable, and locally available alternatives to synthetic insecticides for sustainable management of S. zeamais in stored maize.
