Myrtle Rust – Forest Industry Issues Paper
This report outlines and reviews the potential implications and exposure of the recent discovery in Australia of the exotic plant-disease Myrtle rust (Puccinia psidii). It also aims to provide options to mitigate the impact of Myrtle rust in both the short and longer term. This type of rust has a large range of hosts across the Myrtaceae family, including Australia’s commercial Eucalyptus and Corymbia hardwood plantations.
Initial testing suggests that this strain can germinate under cooler minimum temperatures than strains previously studied overseas; therefore it could spread into much of Australia’s temperate plantation regions. It affects trees from seedling stage through to 2–4 years of age, once trees are 3–4 metres high and in mature foliage the impact of the rust is greatly diminished.
A severe rust infection could cause loss of stocking, uneven growth and loss of productivity over a full rotation length, with an estimated annual loss of $105 million.
There is likely to be an impact on native forests, which may reduce both the effectiveness of regeneration and also species diversity. This could add to the costs of regeneration after harvesting and/ or lengthen rotations.
The report includes a list of operational, research and biosecurity options.