Quarantine treatment of fresh fruits using irradiation - recent development in market potential and future prospects for Asia and the Pacific

Agricultural exports are important sources of foreign exchange for many developing countries in Asia and the Pacific. These horticultural commodities from countries endemic with quarantine pests, especially fruit fly of the Tephritidae family, have to be treated to satisfy strict regulations on plant protection and quarantine in major importing countries. The prohibition of ethylene dibromide (EDB) as a food fumigant by the US Environmental Protection Agency in 1984 followed by Japan's Ministry of Agriculture, Forestry and Fisheries in 1987, have jeopardized trade in fresh fruits and vegetables originating from tropical and sub-tropical countries. Alternative treatments to satisfy quarantine regulations have been used with limited degree of success. Irradiation by gamma rays has been demonstrated as a viable alternative. The USDA Animal Plant Health Inspection Service (APHIS) accepted irradiation as a quarantine treatment against various species of fruit fly infesting Hawaiian papaya in early 1989. The North American Plant Protection Organization also accepted irradiation as a quarantine treatment of fresh fruits and vegetables in late 1989. A review will be made on the status of research and development on irradiation as a quarantine treatment especially as viable method to overcome trade barriers on tropical fruits. Research carried out under the sponsorship of FAO and IAEA in the past five years demonstrated that a minimum radiation dose of 150 Gy is effective to disinfest fruits and vegetables against all species of fruit fly tested without affecting the quality of host commodities. A minimum dose of 300 Gy is effective against mango seed weevil, mites and other insects which are subject to quarantine restrictions in certain importing countries. An international protocol to demonstrate the efficacy of irradiation as a quarantine treatment on a practical scale will be described. 10 refs, 4 tabs