A world-first technique that eradicates a devastating plant pathogen on a large scale has been developed by Murdoch University and industry partner Alcoa of Australia.

In just two years, researchers used an old farming method known as fallowing on haulage roads used by Alcoa to eradicate phytophthora dieback from an infected network of roads in South-West Western Australia.

Fallowing involves allowing land to lie idle, helping it to recover. To fallow the haul roads, the roads were closed and quarantined, while any remaining regrowth was controlled for the duration of fallowing.

The trial provided a major breakthrough, and was based on research conducted at Murdoch that showed the pathogen required living plant hosts to survive, and is unable to survive for long periods in the absence of plants as was previously thought. 

Dieback destroys plants' root structure

Phytophthora dieback disease was first recorded in WA in the 1920s and kills plants by destroying their root structure. It has been associated with the deaths of the dominant South-West tree species Jarrah and 40 per cent of plant species growing beneath the forest canopy.

The disease, which is found in more than 70 countries, is spread through infected soil and mud, especially by vehicles and footwear.

Managing the disease has been the subject of decades-long investment and research by Murdoch and Alcoa.

Professor Giles Hardy, who led the team that worked with Alcoa, said the method was already being adapted by government and industry to tackle dieback infestations in different locations.

“Aspects of the fallow approach are being used to try to rid the Fitzgerald River National Park, near Bremer Bay, of dieback,” Professor Hardy said.

“Eradication of this pathogen was previously thought impossible. The method we developed might seem so simple and obvious, but has actually been quite a big journey, and to prove the roads were dieback-free involved new techniques and methods.

“Dieback is a serious threat to South-West WA’s status as a biodiversity hotspot, so we are thrilled to have found a workable solution to prevent its spread in certain circumstances.”

Andrew Grigg, Alcoa Sustainability Manager said: “This collaboration between Alcoa and Murdoch University has had great success. The innovative project not only eradicated the Phytophthora dieback pathogen on a large scale but also solved a significant environmental and business issue for Alcoa.”

Golden Gecko finalists

The project was a finalist for the annual Golden Gecko awards, presented in Perth last night. It received a Merit certificate at the awards, which recognise leading practice and innovation in environmental management and are presented by the State Department of Mines, Industry Regulation and Safety.

An upgraded early warning system at WA ports from Broome to Esperance and a project aimed at understand ghost bat ecology in the Pilbara were joint Golden Gecko winners.