A world authority on potato cyst nematode (PCN) is assisting the Department of Agriculture, Western Australia in planning the preliminary stages of a survey to prove State-wide freedom from the pest.

Senior Scientist Dr John Marshall of Crop and Food Research, Lincoln, New Zealand, visited the Department’s Nematology Laboratories at South Perth to discuss sampling strategies and the validation of the testing systems which will be used during a three-year project to confirm the absence of PCN from Western Australia's potato-growing areas.

Dr Marshall has developed expertise in the biology and detection of PCN over 30 years of research dedicated to this pest.

PCN was first detected in WA in 1986 in a potato-growing area at Munster on the southern boundary of Perth. It was the first time PCN had been detected in Australia and Dr Marshall helped shape the initial response to the detection. On his advice a policy was developed which included annual surveys. PCN has not been found in WA since 1989.

Dr Marshall believes it is most likely that PCN has died out on those sites where it was first detected, largely because the organism’s host plant was removed. Potatoes are no longer grown at those sites and much of the area is being developed for housing.

Soil samples will be tested again from the sites of original infestation and from other potato-growing properties in the Perth district. Samples will then be tested from all other potato-growing regions of Western Australia, including properties which produce seed potatoes.

Samples from the surveyed areas will be assessed by biological testing and the use of DNA technology developed by Dr Marshall and his colleagues in New Zealand.

Because PCN had been detected previously, some importing countries presently apply export endorsements or restrictions to Western Australia's potato exports.

The main purpose of surveying for the pest over the next three years is to prove that WA is free from PCN.

It can be expected that substantial benefits in market access and exporting will result from a declaration of Area Freedom.

Sam Calameri, Agricultural Produce Commission and chairman of the Potato Producers’ Committee, said if WA could be declared free of PCN it would be of great benefit to the potato seed export trade.

Some 2000 ha of potatoes are grown annually in Western Australia, producing 10,000 tonnes of seed potatoes and 87,000 tonnes for domestic consumption, processing and export.

Dr Marshall will continue to collaborate on the project from his headquarters in the south island of New Zealand.

The project is led by senior nematologist Dr Vivien Vanstone, supported by technical officer Sarah Collins and Peter Phillipe, PCN Manager, Western Australian Quarantine and Inspection Service (WAQIS).

Dr Satendra Kumar, quarantine plant pathologist, Nuccia Eyres, surveillance officer, and quarantine plant pathology staff will assist with this work.

The Western Australian PCN survey is being funded by Horticulture Australia Ltd, with additional support from the Potato Growers Association of Western Australia and the Department of Agriculture.