Phytophthora: An Emerging Threat

15th July 2011
Phytophthora: An Emerging Threat

Phytophthora Dieback kills plants and infection is permanent. The pathogen attacks the roots of plants, travels in water and along root systems and is spread in contaminated soil. This can be via small amounts of soil attached to shoes of walkers up to large soil disturbances during major earth works. Highly
susceptible plants die quickly but even those that are not highly susceptible will succumb during long periods of dry weather. The loss of root mass limits the amount of water and nutrients the plant can absorb, leaving it susceptible to insect attack, other diseases and drought stress. The pathogen poses a
significant threat to ecosystems functions by altering and reducing species composition and structural form of the vegetation. Native birds and animals, invertebrates and microflora may all be threatened by these changes in vegetation. There are only three management objectives for Phytophthora Dieback: keeping areas free of infection, limiting the spread and managing infected sites using hygiene, quarantine, and treatment of infected plants.

What you can do to prevent spread:

There are already some known outbreaks of the disease in the Illawarra region, and it is impossible to eradicate Phytophthora from infested areas once present. So limiting further spread is critical to management efforts. You can reduce the chances of spreading the disease by:

  • Preventing the movement of infected soil or plant material
  • Cleaning your shoes when moving in or out of bushland areas
  • Making sure your tools are clean before you start working. This can be done by spraying tools with 70/80% methylated spirits
  • Ensuring your planting material comes from a reputable nursery
  • If you think you may have dieback on your site, you can have your soil tested for the presence of Phytophthora

For more information about what you can do to prevent the spread of Phytophthora visit:

The Royal botanic Gardens Website

or download the ‘Phythophthora Root Rot’ fact sheet.