Insect infestations in stored grains are a major post-harvest problem worldwide. They lead to weight loss, reduced nutritional quality, contamination, and lower market value. Traditional chemical fumigants such as phosphine have been widely used, but their effectiveness is declining due to insect resistance, and they raise environmental and health concerns. As a result, plant-based alternatives like peppermint, eucalyptus, and citral oils are being explored because they are biodegradable, relatively safe, and have strong insect-repellent or insecticidal properties. However, a key limitation is that these plant-derived substances often have strong, persistent odours. When applied in grain storage systems, these odors can be absorbed by grains, affecting their taste, smell, and overall market quality. This creates a practical barrier to large-scale adoption of plant-based pest control methods.
The main challenge, therefore, is balancing effective insect control with the preservation of grain quality, particularly by preventing odour transfer from plant materials into stored grains.
Key questions are: 1. How can encapsulation, controlled-release formulations, or physical separation techniques be used to prevent odor migration from plant-based insect repellents into stored grains while maintaining their insecticidal effectiveness?
2. How can the insect-repellent efficacy of plant-derived materials (e.g., peppermint, eucalyptus, and citral oils) be utilized for stored-grain protection while preventing the transfer of their strong odors into the grain?