Onion rust: declared pest

Page last updated: Tuesday, 30 July 2019 - 3:49pm

Please note: This content may be out of date and is currently under review.

Onion rust (Puccinia allii) is a disease of plants in the onion family, including onions, garlic, chives, spring onions and leeks.

This disease is not known to occur in Western Australia. Early detection and reporting of onion rust will help protect the Western Australian onion and garlic industries.

What plants are affected? 

Onion rust is most severe on garlic and chives but also affects onions, spring onions and leeks. It is sometimes called garlic rust.

What to look for

  • Rust appears on the leaves as bright orange or dark brown bumps along the leaf veins.
  • Black or orange spores break out of the lesions as the infection develops.
  • When rust infection is severe the leaves may die.
Onion rust symptoms on garlic leaf.

Survival and spread 

  • The rust fungus produces many spores which are spread by wind and rain splash.
  • Onion rust can be spread on infected planting material such as shared mother bulbs.
  • Garlic imported for human consumption may carry onion rust to new areas if planted in home gardens.


Crop losses can be severe, depending on the strain of rust and the plant host. Even a few lesions can reduce marketability in crops like spring onions where the leaves are consumed.

Status in Western Australia 

Puccinia allii (D.C.) F. Rudolphi 1829 is considered absent from Western Australia and is a quarantine pest. It is a prohibited organism under section 12 of the Biosecurity and Agriculture Management Act 2007.

Western Australia's Pest Freedom for onion rust is supported by general and specific surveillance, specific import requirements to prevent its entry, and legal requirements to report any occurrences of the pest.

Report suspect disease 

Several species of rust which can affect onions, garlic and chives are not found in Western Australia. Any rust symptoms that appear on onions, garlic, shallots or chives should be reported.

It is important that any suspect disease occurrence is reported. Early detection and eradication will help protect Western Australian onion and garlic growers. Please make a report using MyPestGuide or contact the Pest and Disease Information Service (PaDIS) to report this pest.

Report pest observations

Contact information

Pest and Disease Information Service (PaDIS)
+61 (0)8 9368 3080