QUARANTINE IN RELATION TO AUSTRALIAN CITRUS IMPORTS AND EXPORTS

The risks of introducing exotic citrus diseases through the importatio n of citrus fruit, seed and budwood are discussed. The experience with citrus bacterial spot in Florida has demonstrated that species identi fication and even pathogenicity testing are no longer adequate; serolo gical and biochemical typing are essential before substantial eradicat ion programs are commenced. A protocol for citrus budwood importations is discussed and an example given of the problems caused by accepting virus-free budwood from an 'approved' source. Allowing entry of virus es endemic to Australia could have disastrous consequences if more sev ere strains with a wider host range are introduced. The orange and man darin stem pitting strains of citrus tristeza virus are examples given . Citrus relatives e.g. ornamentals such as Murraya can be hosts of ca nker, greening and citrus tristeza virus, and should undergo similar q uarantine procedures to those for Citrus spp.