Phytophthora root rot, a form of 'dieback', is a disease that affects many native plants and ecosystems, important crops and horticultural plants in Australia and throughout the world. Its global spread has been the consequence of trade and human migration.
In Australia, the disease infects an especially large range of mainly woody perennial plant species and is also a major threat to some rare and endangered species.
- Department of the Environment and Heritage, 2009
Image: Phytophthora Dieback resulting in plant death.
Source: Royal Botanic Gardens Sydney and Environmental Trust
Myrtle Rust (Uredo rangelii) 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
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.
What you can do to prevent spread:
For more information about what you can do to prevent the spread of Myrtle rust visit: www.dpi.nsw.gov.au/biosecurity/plant/myrtle-rust