Reducing grain storage losses in developing countries

Authors: Dowell, Floyd; DOWELL, C - Kansas State University

Submitted to: Quality Assurance and Safety of Crops & Foods
Publication Type: Peer Reviewed Journal
Publication Acceptance Date: 5/19/2016
Publication Date: 1/1/2017
Citation: Dowell, F.E., Dowell, C.N. 2017. Reducing grain storage losses in developing countries. Quality Assurance and Safety of Crops & Foods. 9(1):93-100. doi:10.3920/QAS2016.0897.

Interpretive Summary: Stored grain is susceptible to damage and consumption by stored-grain insects such weevils, beetles, and borers. If the insects are not controlled, then losses can be 20-80% within a few months after harvest. Subsistence farmers store 50-75% of grain in developing countries on-farm, but often lack the resources to reduce losses caused by insects. This decreases food security and contributes to malnutrition in these countries that struggle to provide adequate food for their nutritional needs. To address these grain storage problems, we investigated the use of insecticide-treated material and modified atmosphere storage for reducing insect damage in stored maize. Results showed that insecticide treated netting and insecticide treated seed bags protected grain from insect damage for up to nine months if the grain was free from insects before storing. Covering the opening of grain storage containers with treated netting provided good control of stored-grain insects and may offer addition protection for grain silos being promoted in developing countries. Neither treated bags nor netting provided control if the grain contained insects before storage, thus emphasizing the need to provide some means of controlling initial infestations at the time of storage. We also showed that good control of insects can be achieved if the grain is stored in air-tight rigid containers that cannot be penetrated by insects or rodents. Hermetic plastic bags were readily penetrated by insects and rodents, thus negating their ability to protect grain from insects. Modifying the atmosphere by reducing oxygen levels or raising carbon dioxide levels also provided good control of stored-grain pests. These solutions offer farmers in developing countries methods to protect grain from stored-grain insects, thus reducing losses and improving food security.

Technical Abstract: We investigated the use of insecticide-treated material and modified atmosphere storage for reducing insect damage in stored maize. Results showed that insecticide treated netting and insecticide treated seed bags protected grain from insect damage for up to nine months if the grain was free from insects before storing. Covering the opening of grain storage containers with treated netting provided good control of stored-grain insects and may offer addition protection for grain silos being promoted in developing countries. Neither treated bags nor netting provided control if the grain contained insects before storage, thus emphasizing the need to provide some means of controlling initial infestations at the time of storage. We also showed that good control of insects can be achieved if the grain is stored in air-tight rigid containers that cannot be penetrated by insects or rodents. Hermetic plastic bags were readily penetrated by insects and rodents, thus negating their ability to protect grain from insects. We also showed that reducing oxygen levels through the use of a candle in stored environments does little to protect grain from insects. Modifying the atmosphere be reducing oxygen levels or raising carbon dioxide levels also provided good control in stored-grain pests. The solutions outlined in this paper offer farmers in developing countries methods to protect grain from stored-grain insects, thus reducing losses and improving food security.