06 March 2012

MYRTLE RUST UPDATE: distribution, workshops & resources

Myrtle Rust is an introduced plant disease that infects many species in the family Myrtaceae. It has naturalised in coastal areas of NSW and Queensland, and has recently arrived in Victoria. 

ANPC Myrtle Rust Workshops

The ANPC’s comprehensive one-day workshop ‘Myrtle Rust – a new threat to Australia’s biodiversity’ has been delivered at 11 NSW regional locations and one in Queensland. Course notes are being fully updated and further national roll-out is planned.

Please register your potential interest in either attending or in helping to organise a workshop by contacting Bob Makinson. 

Information Resources 

State websites: Key websites in the states of occurrence are:
Queensland: www.dpi.qld.gov.au/4790_19788.htm
New South Wales: www.dpi.nsw.gov.au/biosecurity/plant/myrtle-rust
Victoria www.dpi.vic.gov.au/forestry/pests-diseases-weeds/diseases/myrtle-rust

Domestic quarantine provisions are in place – see www.quarantinedomestic.gov.au/myrtle-rust.html for links.

Key Myrtle Rust documents are now centrally available on the new Commonwealth website http://myrtlerust.net.au. These include:
  • The national Plan for Transition to Management of Myrtle Rust (version 1, Nov. 2011), outlining current Commonwealth-funded projects; 
  • Myrtle Rust Forest Industry Issues Paper (Forest and Wood Products Australia - dated ‘June 2011’ but apparently only released in December. This paper attempts to assess the likely impact on commercial forestry in Australia, and contains the only (so far) public post-mortem on the initial 2010-11 response effort.
  • Management Plan for Myrtle Rust on the [NSW] National Parks Estate (Oct. 2011, NSW Office of Environment and Heritage).
An updated Management Plan for the greenlife sector has just been released by Nursery & Garden Industry Australia. The Australian Nursery Industry Myrtle Rust (Uredo rangelii) Management Plan 2012 updates host lists, plant interstate movement controls, and fungicide treatments. This remains by far the most comprehensive guide for everybody in the plant growing and distribution sectors.

Current distribution and host lists 

Myrtle Rust is well naturalised in coastal areas of NSW and Queensland. In these States, the distribution has remained fairly stable over this wet summer (near-coastal areas from Batemans Bay to about Rockhampton, and in Qld inland to about Toowoomba). In January it was detected for the first time in Victoria.

The host-list for Myrtle Rust has expanded greatly. Since its first detection in Australia in 2010, Myrtle Rust has now been found to infect more than 200 native plant species. The severity of infection, and apparent impact on plants, varies greatly between species. Some genera seem to have most or all species consistently prone to severe infection – these include Rhodamnia, Rhodomyrtus, and Gossia. New seasonal growth is also attacked severely in Melaleuca quinquenervia.

Separate host lists for each State, all fairly up to date, are linked from a new Commonwealth site: www.myrtlerust.net.au (select links).

In Victoria: As at 24 Feb. 2012, Myrtle Rust was known from 25 sites in and around Melbourne and one in the Otways region. Most Victorian sites so far are in production nurseries and plant wholesale outlets, but at least one is in public parkland, and following the pattern in the earlier States naturalisation of the rust on plants in open cultivation and in bushland can be expected. However, attempts are still underway to contain Myrtle Rust to the outbreak area.

To report suspected myrtle rust anywhere in Victoria, please telephone DPI on 1800 084 881, and/or email digital photos of the suspect material, plus location and your contact details, to plant.protection@dpi.vic.gov.au.

DPI Victoria is running awareness workshops: next ones are at DPI Knoxfield on Friday 2 March and Friday 16 March – for more details contact plant.protection@dpi.vic.gov.au.

Elsewhere: A variant of Myrtle Rust’s parent ‘species-complex’ (Guava Rust or Eucalyptus Rust, Puccinia psidii sens. lat.) has now been reported from southern China. Specimens were collected from Rose Apple growing in Hainan in 2009, and are confirmed as P. psidii by Zhuang & Wei (2011; Mycostemma 30(6): 853-860). This is the first occurrence on the Asian mainland (Hainan is an island, but only just). The vast diversity of Myrtaceae in South-west Asia and the south-west Pacific is now at great risk from this disease.
Human movement of infected plant material, and probably of spores on clothes and goods, are a major vector for the disease. People travelling from eastern Australia into these regions should take great care to launder all clothing and equipment before departure, especially if trekking or visiting lowland forest areas.

Update prepared by Bob Makinson.

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