Phytophthora Dieback is the name used to describe the plant disease caused by the Oomycete Phytophthora cinnamomi. There are many species of Phytophthora, but P. cinnamomi causes the most severe and widespread damage to native vegetation.
Phytophthora Dieback spends its entire life in the soil. It attacks the roots of plants and causes them to rot. This kills the plant by stopping the uptake of water and nutrients.
Phytophthora Dieback is found all around the Perth metropolitan area causing disease in our native banksia woodlands and jarrah forests as well as affecting plants in private and public gardens, and street-scapes. Up to 40% or 2,300 of the native plants in the southwest of WA
are susceptible to Phytophthora Dieback.
The introduction of the pathogen results in dramatically altered plant communities which have a greater susceptibility to additional threats such as invasive weeds. These changes result in the loss of plant habitats which provide food and shelter for marsupials, birds, reptiles and insects.
The pathogen is able to survive within plant roots and soil during the dry soil conditions commonly experienced during the summer months via special survival spores.
Consequently, once in an area it is unlikely to disappear irrespective of the absence of susceptible plant species.
How does the pathogen spread?
In sloping areas Phytophthora Dieback spreads quickly when the microscopic spores move downwards in surface and sub-surface water flows. It spreads slower up-slope and on flat ground (approximately one metre per year) because it is restricted to movement by root-to-root
However, it is human activity that causes the most significant, rapid and widespread distribution of this pathogen. Road construction, earth moving, driving vehicles on bush roads and stock movement can all contribute significantly to the spread of Phytophthora Dieback.
Bush restoration projects may also inadvertently spread the pathogen. Soil that is warm and moist provides the best conditions for Phytophthora Dieback. These conditions allow the pathogen to produce millions of spores. These spores are attracted to the plant roots by swimming through the soil water.
Dieback management procedures and protocols
Whether or not Dieback has been identified within a natural area, it is necessary to manage for Phytophthora Dieback to prevent its introduction to, or spread within, such areas. Once Phytophthora Dieback becomes established at a site it is very difficult to eradicate it, and
management of the disease must aim to prevent further spread within infected areas and prevent spread of the disease into new areas.
The Town has developed aDieback Management Procedures and Protocols(PDF, 818KB) guide, the purpose of which is to provide specific guidelines regarding the management of Phytophthora Dieback (caused by Phytophthora cinnamomi) throughout the Town of Victoria Park.
The Town is also undertaking monitoring of Kensington Bushland for dieback, through soil and vegetation testing.
The management of Dieback will be also be a strong focus of the forthcoming Kensington Bushland Management Plan.
What you can do?
You can play a vital role in stopping the spread of Phytophthora dieback:
• look out for information signs in Kensington Bushland and follow the instructions
• do not move soil or plant material
• use the boot cleaning stations provided before entering the bushland
• always stay on tracks and paths
• stay out of quarantined areas in bushland and forest.