RIRDC - Research Compendium 1993

Rural Industries
Research & Development Corporation

Research Compendium 1993 - 1994

Research Project

REVIEW OF PHYTOPHTHORA DISEASES IN AUSTRALIA

Objectives

To undertake a state and territory analysis of the diseases caused by Phytophthora. For each state and territory the problem to be broken down into:

the Phytophthora species involved and the crops affected;
economic impact;
current management;
current research;
research and development priorities and potential returns; and
general conclusions and recommendations.

Background

In Australia, diseases caused by Phytophthora species occur in a wide range of horticultural industries, in pastoral, ornamental and forestry industries and in many national parks and reserves. Diseases caused by Phytophthora are of significant economic importance and impose limitations on the productiveness and further expansion of many crops Australia-wide. In national parks, reserves and state forests, Phytophthora threatens conservation values, reduces species diversity and may cause species extinction. Economically it also affects tourism, reduces timber quality and harvestable volumes and may indirectly increase salination of water supplies.

Outcome

Plant pathogenic Phytophthora species are responsible for significant economic losses across horticultural, ornamental and pasture crops in Australia. It was estimated that direct loss due to Phytophthora disease was at least $223 million across these industries in 1991-1992, equivalent to 3.23% of the estimated gross value of these industries in Australia. Losses to the forestry industry in both softwood plantations and state forests and cost of disease management are significant in Western Australia, South Australia and Victoria. Phytophthora disease imposes severe limitation to the expansion of several industries especially in the ornamental sector.

In 1993, 84% of diseases caused by Phytophthora species were considered able to cause greater damage and loss or were unable to be controlled. Phytophthora cinnamoni is the most widespread and causes disease in many plant species across a range of commodity species and in national parks and state forests in most states.

Other species that are widespread and cause considerable damage and loss include P. clandestina (subterranean clover), P. cactorum (pome and stone fruits), P. nicotianae (tomato, ornamentals), P. infestans (potato), P. cryptogea, P. megasperma, P. parasitica, P. citricola (ornamentals, native species).

Implications

Five key areas were identified for R&D on Phytophthora in Australia: