‘From Common to Critical in less than 10 years.’

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Myrtle rust (Austropuccinia psidii)

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What is myrtle rust?

Myrtle rust is a disease caused by the exotic fungus Austropuccinia psidii (formerly Puccinia psidii, initially identified as Uredo rangelii). Overseas there are known to be several strains of P. psidii. At this stage Australia has only one strain.

Myrtle rust threatens trees and shrubs in the Myrtaceae family of plants which includes Australian natives like bottle brush (Callistemon spp.), tea tree (Melaleuca spp.) and eucalypts (Eucalyptus spp., Angophora spp., and Corymbia spp.). The disease can cause deformed leaves, heavy defoliation of branches, reduced fertility, dieback, stunted growth, and plant death.

Source: Department of Agriculture, Water and the Environment: Myrtle rust (Austropuccinia psidii)

 

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Many will have heard of the Myrtle Rust disease that is attacking dozens of Myrtaceae species in the wild – Llllypillys, Rhodamnias, Rose myrtles, Paperbarks and many more. Few of us would realize just how much damage it has wrought on our native forest ecosystems. Three species once common in the Tweed are now on the brink of extinction and many more look set to follow.

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Volunteer group Earth Learning has been collecting a selection of affected species and propagating them under license as part of a Saving Our Species initiative. The plants are direct clones of parents in the wild. The idea is to preserve a genetic representation of these iconic species, some with restricted range, which are barely hanging on in the wild.

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Earth Learning member botanical specialists have closely cooperated with NSW National Parks under licence to collect Rhodamnia rubescens (Scrub Turpentine) and Rhodomyrtus  psidoides (the Native Guava).  Once regarded as common, these species are now listed as Critically Endangered in the wild due to Myrtle Rust, which is wind blown, and reaching all lowland and highland areas of the Tweed/ Border Ranges, reducing the plant's ability to flower, fruit and reproduce.

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The first cuttings were collected by Lui Weber and delivered to Limpinwood Gardens Nursery for propagation in 2019. Various populations were visited to ensure the sample was 

stratified to increase and enhance the diversity of the genetic material for a known plant species. 

 

The healthy and surviving cuttings were 'potted-on' by volunteers. Particular special acknowledgement should be made about the long hours and intense dedication to this project by Marion Riordan.  Her leadership, time and effort was truly a sacrifice, particularly as during this time, the project was also affected by COVID restrictions and closures of the QLD/NSW state border for an extended period of time. 

 

The collection of plant material was mapped and tracked befitting such a special botanical collection and a copy of the final spreadsheet details were conveyed to Mt Annan Botanical Garden to evaluate which of the specific populations and plant material were to be admitted into the national collection. The requested species were shipped in late 2022.

 

The remaining materials have been distributed to other regional botanical gardens (Lismore and the Sunshine Coast), the Mullumbimby Arboretum, the University of Queensland, as well as local privately held sites with appropriate land tenure with nature protection and aspect/conditions suited to the species. This acts as an additional insurance policy to the primary site.

 

Locations were identified and agreement sought with private landholders in Limpinwood, Farrants Hill, Coffs Harbour, Mullumbimby, Main Arm, Goonengerry, Coopers Creek, Wilsons Creek and Uki to hold propagated plant material sourced largely from the Tweed and Richmond Valleys.

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Links to pages and PDFs are in "Further Information" below.

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Further Information  (Please note, external links below open in a new window.)

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• Myrtle Rust in Australia – a National Action Plan

  • Myrtle Rust National Symposium 2021 (Video presentation by Craig Stehn.
    NSW - Saving our Species Myrtle Rust program - 10 mins)

  • Myrtle Rust National Symposium 2021 (Video presentation various presenters.
    Toward Recovery Myrtle Rust program - 2 hours, 10 mins.)

 

Myrtle Rust Management and Treatment

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• NSW NPWS Management Plan for Myrtle Rust on the National Parks Estate

• Hygiene guidelines:  (PDF link) Protocols to protect priority biodiversity areas in NSW from Phytophthora cinnamomi, myrtle rust, amphibian chytrid fungus and invasive plants

• NSW DPI: Production Nursery Freedom, Treatment and Inspection for Myrtle Rust

• AgVIC: Treating myrtle rust in home gardens

 

Additional information

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• NEW!  Most of Lord Howe Island closed to visitors after outbreak of plant fungus (17/03/23)

• NEW!  Landcare Australia: Myrtle rust: A threat to Australia’s unique biodiversity

• Australian Network for Plant Conservation - Myrtle Rust information hub

• Commonwealth Dept AWE: Myrtle rust (Austropuccinia psidii)

• NSW DPI: Myrtle rust in Australia  |  Myrtle rust.  July 2015 Primefact 1417 First edition (PDF)

• NEW! NSW DPI: web site search query "myrtle rust"

• Business Queensland: Myrtle rust

• Biosecurity Tasmania.  Myrtle rust  (PDF)

• Landcare Research New Zealand - Beyond Myrtle Rust