Exotic watch: Citrus canker

Rebekah Pierce, Plant Biosecurity Officer, NSW DPI

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An exotic plant pest is a disease causing organism or an invertebrate not present in New South Wales and which threatens agricultural production, forestry or native and amenity plants.

Citrus canker is a highly contagious bacterial disease, widespread in many tropical and subtropical citrus-growing regions of the world. All commercial citrus cultivars are susceptible to citrus canker. Canker spots blemish fruit, making fruit unmarketable. Severe infection can lead to defoliation, dieback and premature fruit drop.

New South Wales (NSW) is currently free of citrus canker. An eradication effort is underway in the Northern Territory and Western Australia.

Lesions on a tangelo

Introduction of citrus canker into NSW can occur with the movement of infected plants or plant parts including nursery trees and propagation material. Budwood should only be imported through legal channels and tested in post-entry quarantine facilities before release. Once introduced, citrus canker is easily spread with the movement of water including wind-driven rain, irrigation and in water droplets on contaminated tools, equipment, orchard workers, birds and insects.

There is no effective control for citrus canker. Management guides focus on practices for prevention. Citrus growers must remain vigilant and report any suspicious disease symptoms to ensure Australia's citrus industry remains free of citrus canker and other exotic citrus diseases.

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Information on how to recognise and protect your property from citrus canker is available from the NSW DPI website. Information about exotic pests and biosecurity for citrus orchards is available in the industry manual and is available from the Citrus Australia website.

If you suspect citrus canker in Australia call the Exotic Plant Pest Hotline on 1800 084 881.

More information

For more information on exotic pests, contact Rebekah Pierce.