Postharvest Phytosanitary Radiation Treatments: Less-Than-Probit 9, Generic Dose, and High Dose Applications

With world trade in agricultural commodities increasing, the introduction of exotic insects into new areas where they become pests will increase. Interest in the use of irradiation as a phytosanitary treatment for agricultural commodities is growing worldwide, particularly since International Plant Protection Convention (IPPC) and Codex Alimentarius standards now endorse and facilitate trade based on this disinfestation method. Irradiation is broadly effective against insects and mites at doses that do not compromise quality of most commodities. Unlike other disinfestation techniques, irradiation does not need to kill the pest immediately to provide quarantine security, and therefore live - but not viable or sterile - insects may occur with the exported commodity making inspection for the target pests redundant. Generic irradiation treatments are being developed to control broad groups of insects or insects in all commodities, and will expedite new trade in agricultural products. High dose or default dose treatments are also being used by determining an irradiation dose at the upper limit of what is believed to control the insect groups that infest a commodity without specific data for the quarantine species of concern. For quarantine insects on poor or rarely infested hosts, or that are effectively managed as a result of effective preharvest area-wide pest management for export under a systems approach, the probit 9 standard for quarantine treatment efficacy - 99.9968% mortality - can be replaced by risk-based less-than-probit 9 approaches that reduce the severity of the quarantine treatment and the number of insects required for testing during treatment development. The availability of generic and high dose treatments makes irradiation an attractive option compared with other quarantine treatments.

KEYWORDS irradiation, postharvest, quarantine, phytosanitary treatments, agricultural trade, IPPC, probit 9, generic dose, high dose