Biopesticide granules based on essential oils for the protection of wheat grain during storage

Abstract: Biopesticide granules based in cereal by-products and essential oils were developed for wheat protection during storage. The elaboration process of the granules was performed by an extrusion process. The essential oils used were selected from their known insecticidal and fungicidal activity. Insecticidal tests using the biopesticide granules have been conducted against Rhyzopertha dominica and Sitophilus oryzae in contact with wheat grain simulating storage conditions of temperature and relative humidity. The insecticidal effect was evaluated after 14 days. The mortality of both species was dependent on the nature, concentration, and release rate of the essential oil. The highest mortality reached was of 93% for a high load of insects (100 insects/kg of wheat grain). In addition, fungicide essays were carried out against Aspergillus westerdijkiae and Penicillium verrucosum. The germination and growth of the microorganisms and ochratoxin A (OTA) production were evaluated. The results were strongly dependent on the essential oil nature released by the biopesticide granules. The findings suggest that the obtained biopesticide granules could be an alternative solution for the control of infestations in stored crops.