Sustainable Solutions for Wheat Grain Protection: Evaluation of Inert Materials against Rice Weevil (Sitophilus oryzae L.)

Abstract

This study investigated the potential of three readily available inert materials – apple wood ash, kaolin, and silica – for controlling the rice weevil (Sitophilus oryzae L.), a pest of stored grains. We evaluated their efficacy at three concentrations (2%, 4%, and 8%) against adult weevils over an 8-day treatment period. Apple wood ash emerged as the most potent material, achieving a remarkable 100% cumulative mortality rate on the eighth day at the highest concentration, statistically exceeding the performance of kaolin (90%) and silica (40%). The untreated control group exhibited a significantly lower mortality rate of 6.66%. Beyond immediate mortality, both apple wood ash and kaolin demonstrated outstanding ability to protect wheat grains from infestation damage. Treatment at 8% significantly reduced the emergence of new adult weevils, minimized grain damage percentage, and mitigated of weight loss. Apple wood ash displayed remarkable effectiveness, with protection values exceeding 95% for all three parameters (emergence: 96.02%, damage: 89.09%, weight loss: 91.68%). Kaolin also performed well, achieving close to 90% protection in all categories (emergence: 89.55%, damage: 84.13%, weight loss: 88.24%). Conversely, silica displayed a significantly lower efficacy, with protection values hovering around 55% for all parameters (emergence: 56.40%, damage: 51.48%, weight loss: 56.64%). These findings highlight the promising potential of readily available inert materials, particularly apple wood ash and kaolin, as eco-friendly alternatives to synthetic insecticides for managing rice weevil populations in stored wheat. Their integration into pest management programs offers a sustainable and effective approach to minimizing grain losses and preserving food security.