What is Myrtle rust?
Myrtle rust (Puccinia psidii s.l.) is a newly described fungus that is closely related to the Eucalyptus/Guava rusts. These rusts are serious pathogens which affect plants belonging to the family Myrtaceae including Australian natives like bottle brush (Callistemon spp.), tea tree (Melaleuca spp.) and eucalypts (Eucalyptus spp.).
Myrtle rust is distinctive in that it produces masses of powdery bright yellow or orange-yellow spores on infected plant parts. It infects leaves of susceptible plants producing spore-filled lesions on young actively growing leaves, shoots, flower buds and fruits. Leaves may become buckled or twisted and may die as a result of infection. Sometimes these infected spots are surrounded by a purple ring. Older lesions may contain dark brown spores. Infection on highly susceptible plants may result in plant death.
Living with myrtle rust
Tools to use
Permits issued by the Australian Pesticides & Veterinary Medicines Authority (APVMA) enable chemical treatments to be applied:
- PER12319 are relevant to commercial businesses
Factsheets and further information are available on the myrtle rust resources page.
Slowing down disease spread
The NSW Office of Environment & Heritage maintains a map of myrtle rust distribution through the Atlas of NSW Wildlife. General observations can help provide information about the impacts that myrtle rust is having in NSW.
The Office of Environment & Heritage has identified high value environmental assets and threatened species at risk and is monitoring these sites.
National parks, local councils and other organisations that manage tracts of natural vegetation continue to implement biosecurity measures to protect threatened plant species and vegetation communities and to ensure the risk of spread to new areas by workers and visitors is reduced.
New hosts and detections in previously uninfected areas of NSW are referred to the Department of Primary Industries because myrtle rust remains a notifiable pest under the Plant Diseases Act.
An Interstate Certification Assurance (ICA) arrangement, ICA-42 Production Nursery freedom, treatment and inspection for Myrtle Rust has been developed to assist businesses trading in myrtle rust host plants to comply with interstate quarantine requirements.
What can I do
- use awareness material
- read advise packages and biosecurity guidelines for your industry or interest group
- develop a myrtle rust management plan for your business
- apply fungicides according to APVMA permits
- replace diseased plants with non-susceptible plants (for example plants not in the myrtaceae group)
- practise vehicle and personal biosecurity hygiene
Host list and distribution in NSW
There are over 100 known naturally susceptible host species in NSW. Areas most suceptible to infection are the NSW eats coast and ranges. The distribution of Myrtle rust in NSW is shown by red and green zones.
Myrtle rust is not reportable in NSW
If you live in NSW it is no longer reportable.
Resources and factsheets
Information is available on the resources page for home gardeners, bush regenerators, nursery and garden industry and the tea tree industry.
Myrtle rust response in NSW (2010-2012)
An historical summary of how NSW responded.
- NSW Office of Environment & Heritage Management Plan for Myrtle Rust on the National Parks Estate (www.environment.nsw.gov.au)
- Tea tree industry (www.attia.org.au)
- Nursery and garden industry (www.ngia.com.au)
- Australian native foods (www.anfil.org.au)
- New Rural Industries Australia (www.nria.org.au)
- AQIS (www.daff.gov.au)
- Victoria (www.dpi.vic.gov.au)
- Western Australia (www.agric.wa.gov.au)
- Queensland (www.dpi.qld.gov.au)
- Northern Territory (www.nt.gov.au)
- Australasian Plant Pathology Society (www.appsnet.org)