Novel Irradiation Technology for Phytosanitary Treatment of Food Commodities and Promotion of Trade

The commercial use of ionising radiation as a post-harvest phytosanitary measure to overcome trade restrictions on fresh food commodities is increasing. It involves gamma, electron beam and x ray irradiation to doses less than 1 kGy and enables trade of agricultural products that would otherwise be restricted due to risk-based pest controls on shipments of fresh commodities. However, most irradiation treatments in international standards are specific to one pest species. It is desirable to have generic treatments with one radiation dose applicable to a broad range of different pests. Therefore, research will first identify the most radiation-tolerant pest species in each of the key pest groups for trade (see list below). In phase 2, tens of thousands of individuals of these "most-tolerant" pests will be reared and experiments will be used to confirm efficacious generic doses. These efficacious treatment doses of radiation will be proposed for inclusion in the standards of the International Plant Protection Convention as International Standards for Phytosanitary Measures. These new generic irradiation treatments, plus those already in place, would address over 90% of quarantine issues for fresh fruits and vegetables and be a major accomplishment for the commercial use of phytosanitary irradiation. Factors that might affect treatment efficacy will also be investigated to foster innovation by encouraging novel research and technology that could enhance the effects of ionising radiation on pest species and/or improve radiation tolerance of the fresh commodity (e.g. mode of delivery of the radiation, applied dose rates, oxygen content and any other external factors that may be optimised to improve the phytosanitary measure).
KEY PEST GROUPS FOR GENERIC DOSE PHYTOSANITARY IRRADIATION
• Weevils of the family Curculionidae• Leaf miners of the family Agromyzidae• Mealybugs of the family Pseudococcidae• Scale insects of the family Diaspididae• Eggs and larvae of the order Lepidoptera• All other regulated insect pests other than pupa and adult Lepidoptera• Mites of the family Tetranychidae• Pupae of the order Lepidoptera• Mites in families other than Tetranychidae