Botanic Gardens Trust, Sydney, Australia

5. Managing Phytophthora Dieback

Use this site to obtain information on how to manage Phytophthora Dieback

  • In home gardens
  • In nurseries
  • In natural areas

Preventing and Managing Phytophthora Dieback in home gardens

Remember good hygiene practices are essential to keeping Phytophthora Dieback out of your garden and reducing its spread.

The brochure Facts about Phytophthora explains what Phytophthora is, how it is spread and how it affects plants and the Factsheet provides details on how to prevent its spread and caring for infected plants in your home garden. Although you can treat infected plants, infection is permanent, so you must be prepared to maintain strict hygiene practices once you have identified Phytophthora Dieback in your garden. You can treat you plants to improve their resistance and help maintain their health but you are unlikely to get rid of the disease once a plant has become infected. The Factsheet will assist you with how to protect and treat you garden plants.

Developing and implementing management plans for Phytophthora Dieback in Nurseries

As with home gardens, good hygiene practices are essential to keeping Phytophthora Dieback out of your nursery and reducing its spread.

Use the information in the brochures Facts about Phytophthora which explains what Phytophthora is, how it is spread and how it affects plants and Factsheet which provides details on how to prevent its spread and caring for infected plants in your home garden and nursery as an introduction to Phytophthora Dieback and its management.

Phytophthora Dieback kills plants and infection is permanent & management objectives are

  • Keeping it out
  • Limiting the spread and
  • Reducing the impact, using
    • Hygiene
    • Quarantine and
    • Treatment or destruction of infected plants.

The five strategies approach developed to manage Phytophthora Dieback in your bushland is equally applicable to managing the disease in the nursery. The main difference is that it’s much easier to manage in a nursery as you have so much more control of plant health. Infection is permanent, so destroy any infected stock and prevent contamination by using good hygiene practices.

The five strategies are

  1. Understand Phytophthora Dieback
  2. Assess for risk of disease
  3. Adjust work practices to reflect risk
  4. Inform all staff, contractors and visitors and 
  5. Treat infections.

These five steps are explained in our brochure, and more details can be found below.

More details on each of these steps are available in Management of Phytophthora cinnamomi for Biodiversity Conservation in Australia, a document prepared for the Department of Environment and Heritage in 2006. More information about this document can be found in the References, links & further information section.

Developing and implementing management plans for Phytophthora Dieback in Natural Areas

The five strategies approach has been developed to manage Phytophthora Dieback in natural areas and is explained in our brochure. Use this strategy to understand the steps required to manage Phytophthora Dieback and the reference section for more details.

The five strategies are

  1. Understand Phytophthora Dieback
  2. Assess for risk of disease
  3. Adjust work practices to reflect risk
  4. Inform all staff, contractors and visitors and 
  5. Treat infections.

More details of the five strategies are provided below and further details are available in Management of Phytophthora cinnamomi for Biodiversity Conservation in Australia, a document prepared for the Department of Environment and Heritage in 2006. More information about this document can be found in the References, links & further information section.

1. Understand Phytophthora Dieback

In order to manage successfully, you need to have a good understanding of what it is you are trying to manage. Because the disease Phytophthora Dieback is caused by a living organism, it’s important that you understand the requirements of this organism in order to manage it. 

Phytophthora Dieback, a plant disease caused by the water mould Phytophthora cinnamomi, occurs in most states of Australia and was once thought to be native to NSW. The findings from the study by Dr C. Howard show that the genetic variation is not greater than found elsewhere in Australia and that there is also a considerable imbalance of mating types, which indicate that Phytophthora cinnamomi is an introduced species in NSW.

The study did reveal that there is a greater amount of genotypic diversity in diseased areas in close proximity to urban areas, indicating that human activity is linked to higher genetic variation in Phytophthora cinnamomi. Disturbingly for land managers the study also revealed that different genotypes found in NSW vary in their pathogenicity on multiple hosts. Put simply, a species may be tolerant to one or more genotypes of Phytophthora cinnamomi but not all genotypes. So although Phytophthora cinnamomi may have been found in an area where there appears to be little effect on the plants present, this could change if a different genotype was introduced into an area. Reinfestation by a new genotype could devastate what appears to be a tolerant ecosystem or species.

Phytophthora Dieback kills plants and infection is permanent. So the only three objectives available are

  • Keeping it out
  • Limiting the spread and
  • Reducing the impact, using
    • Hygiene
    • Quarantine and
    • Treatment or destruction of infected plants.

Use the information in the brochure Facts about Phytophthora which explains what Phytophthora is, how it is spread and how it affects plants and the Factsheet which provides details on how to prevent its spread and caring for infected plants.

The Background Document for the Threat abatement plan disease in natural ecosystems caused by Phytophthora cinnamomi 2007 (PDF file 456 KB) complements the statutory National Threat Abatement Plan (TAP) and provides a wealth of information. The TAP outlines the actions proposed to abate the threat and addresses the statutory requirements of the document. The background document provides supporting information on matters such as the biology of the pathogen, its population dynamics, spread, diagnosis and impacts on biodiversity and management measures. Use this document for more detailed background to Phytophthora Dieback and measures available to manage the disease.

Another great resource is the document by E O’Gara, K Howard, and B Wilson & GE StJ Hardy (2005) Management of Phytophthora cinnamomi for Biodiversity Conservation in Australia. Appendix 1 in Part 2 of the document provides background information on the biology and epidemiology of P. cinnamomi. It provides a good description of the organism, what it looks like, its life-cycle, how it’s spread and rationale for current management approaches. Part 2 - Appendix 1 Phytophthora cinnamomi (PDF file 690 KB).

2. Assess for risk of disease

As outlined in the five strategies approach, once you understand the disease then you can assess your risk, looking at such things as your climate, vegetation, soil type, water movement across the landscape, levels of human activity, etc. The brochure explains how to take soil samples for laboratory analysis, which can be done at any laboratory that is set up for testing or contact the Plant Disease Diagnostic Unit at the Royal Botanic Garden, Sydney for information and pricing at pddu@rbgsyd.nsw.gov.au or 02) 9231 8186. 

A great resource is the document by E O’Gara, K Howard, B Wilson & GE StJ Hardy (2005) Management of Phytophthora cinnamomi for Biodiversity Conservation in Australia which has four parts including National Best Practice Guidelines and two parts dealing with risk assessment; Part 3 - Risk Assessment for Threats to Ecosystems, Species and Communities: A Review (PDF file 1.9 MB) and Part 4 - Risk Assessment Models for Species, Ecological Communities and Areas (PDF file 502 KB). The second document describes the models for assessing the risk of P. cinnamomi to biodiversity in Australia. These models were developed after a review of previous and current studies, unpublished information and expert opinion, in Part 3. Please refer to the recommendations presented in the beginning of the document before using the models. 

All the sections of the document are available on the Commonwealth Government environment website and a detailed outline of the document is in the References & Links section below.

3. Adjust work practices to reflect risk

Managing Phytophthora Dieback - Guidelines for Local Government (PDF file 788 KB), prepared by the Dieback Working Group in Western Australia (2000) is a great document to assist land managers, particularly Local Government managers, to develop Phytophthora Dieback Management Procedures.

Look at other great documents that have been developed by other organisations within Australia to assist in developing Best Practice Guidelines for the Management of Phytophthora Dieback in your area. 

There are National Best Practice Guidelines available on the Commonwealth Government environment website (see detailed outline of documents in the References, links & further information section), provides both background information, models and tools for assessment, planning and  management along with practical advice on such things as developing a range of things like signage and hygiene solutions.
 
Examples of some of the hygiene solutions for vehicles and people from Appendix 2 of the National Guidelines are shown in the photos.

carwash
hygiene-kit

foot-bath

The automatic wash-down facility at the entrance to Alcoa’s Huntly bauxite mine in the south-west of Western Australia, designed to remove soil from trucks and light vehicles entering the mine, thus minimising the probability of introducing Phytophthora cinnamomi to the predominantly disease-free site. Photo: E O’Gara A hygiene kit, containing equipment and information to facilitate the cleaning and disinfection of footwear, small tools and equipment against Phytophthora. The Department for Environment and Heritage in South Australia actively promotes the assembly and use of such kits amongst stakeholders. Photo: R Velzeboer, Department for Environment and Heritage in South Australia The Anakie Scrubber footwear cleaning station consists of a metal ramp and disinfectant bath with an immersion plate for the cleaning of footwear prior entering uninfested areas. Photo: D Peters, Parks Victoria

4. Inform all staff, contractors and visitors

Develop material and protocols to inform all your staff, visitors and particularly contractors to your site on the ways that Phytophthora Dieback is being managed.  Only with everyone’s help and cooperation will you be able to manage the risk.

5. Treat infections

The document developed by the Commonwealth by O’Gara et al., as mentioned above, is a great resource here too. 

phytophthora poster