An Overview of Phytosanitary Irradiation Requirements for Australian Pests of Quarantine Concern

Phytosanitary irradiation is used to prevent the introduction or spread of unwanted plant pests and diseases found in horticulture commodities, both in a domestic and international trade setting. Australia started exporting irradiated horticulture commodities to New Zealand in 2004. Since then, exports of irradiated products have continued to grow as phytosanitary irradiation has become more widely accepted for the treatment of plant pests by our international trading partners. Domestically, Food Standards Australia New Zealand (FSANZ) now allows irradiation of all fresh fruits and vegetables using an irradiation dose of 150 to 1000 Gy for all insect pests. To facilitate further domestic and international trade in Australian irradiated horticulture products, we conducted a literature review to perform the following: (1) identify information gaps (minimum absorbed irradiation dose) for Australian pests of quarantine concern, and (2) identify where differences may exist between the minimum absorbed dose and the regulated dose set, and that is accepted by Australia and key international trading partners. In Australia, a minimum absorbed dose of 400 Gy can be used to treat all insect pests of quarantine concern. However, a lower minimum absorbed dose of 150 Gy is used for many fruit fly species that are important for domestic and international trade. For a limited number of priority insect and non-insect pests highlighted by the horticulture sector, there were gaps found for minimum absorbed irradiation dose in the literature. These pests include Vineyard snail, Serpentine leaf miner and Fuller’s rose weevil. Studies to establish the minimum absorbed dose for Vineyard snails, Serpentine leaf miners and Fuller’s rose weevil are recommended. In addition to the gaps identified for irradiation dose, there is merit in conducting further research to refine (lower) the minimum absorbed dose for specific pests and priority commodities where irradiation has an impact on quality. A reduction in dose may not only benefit product quality but will also reduce both treatment time and cost.