Integrated use of pesticides in grain storage in the humid tropics

• Malaysian Agricultural Research and Development Institute, Malaysia
• National Postharvest Institute for Research and Extension, Philippines

Co-operative efforts between research and industry groups within Australia have developed and implemented integrated pest control programs that have virtually eliminated losses due to pests in bulk stored cereals in this country. The current project seeks to further develop effective treatments and to determine data relevant to storage of high-moisture grains and legumes in the tropics. It will include studies to determine: how high levels of grain moisture affect the biological activity of grain protectants and fabric treatments, including treatment of bag stacks; the comparative effects of a range of cereal and legume species on biological activity of grain protectants; and how phosphine fumigation affects germination of seed fumigated at high moisture levels. Field trails in Australia, Malaysia and the Philippines will evaluate fabric and grain protectant treatments developed in the project and test any necessary integration with fumigation and other control measures.
Scientists in Queensland will conduct basic research on the performance of grain protectants and fabric treatments at high levels of grain moisture and relative humidity. They will also study the comparative efficacy of protectants on a range of grains and develop theories to describe these behaviour patterns. Parallel studies on kinetics of pesticide decay will be carried out in collaboration with the scientists in ACIAR Project 8311.
Before beginning field trials, each regional research group will conduct surveys of the pesticide-resistance status of major pest species in the region, establish typical strains in laboratory culture and verify minimum effective doses in local grains. Field trials will involve treatment of building fabrics, bag stacks and grain bulks in commercial storages, using treatments and application rates suggested by the basic studies. The teams will bioassay grain samples and determine residues analytically.
Support studies in Queensland will determine the effect of phosphine fumigation on germination of seeds with high moisture content.
It is expected that the research will not only develop systems of integrated pest control to reduce storage losses, but will provide basic understanding of how grain moisture and grain species influence the biological activity of pesticides used to protect stored grain.