THE blight of the WA potato industry is worse than originally reported and it is unclear how and when things will improve now that WA farmers will have to live with the tomato potato psyllid (TPP) and Dickeya dianthicola bacteria.
The Department of Primary Industries and Regional Development (DPIRD) confirmed last week that five properties in the potato-growing areas north and south of Perth have had quarantines lifted after extensive work in tracing the origins of the Dickeya dianthicola bacteria.
The bacteria was detected for the first time in June in a potato crop north of Perth, prompting an immediate biosecurity response.
DPIRD irrigated agriculture executive director John Ruprecht said extensive tracing, surveillance and testing of samples to determine the spread of the bacteria had led to it being detected in dahlia tubers in WA and freesia bulbs imported from Victoria.
Dickeya dianthicola has also been detected on dahlia tubers grown on a commercial property in Victoria.
“From the initial detection, the department has made tracing a priority to not only determine the extent of the outbreak, but to also identify potential pathways and the source of the disease outbreak,” Mr Ruprecht said.
“Twenty-seven properties were sampled and there were tracing activities to some 64 properties.”
In response to these results, other States have been asked to also survey and test for the pathogen.
DPIRD has provided tracing information to other jurisdictions and affected industry bodies to assess the national response options.
Dickeya dianthicola can cause blackleg and soft rot diseases in potatoes and affect other horticultural crops, including some ornamental varieties, chicory and globe artichoke.
“This detection obviously came at a difficult time for our horticulture industry following the detection of the insect pest, tomato potato psyllid, earlier this year,” Mr Ruprecht said.
DPIRD will work with WA industry to develop management options through the WA Certified Seed Potato Scheme, on-farm biosecurity and best management practices to minimise damage from the bacteria.
Mr Ruprecht said as part of this response, DPIRD had developed a rapid and high-throughput PCR test for Dickeya dianthicola – the first of its kind to be used in Australia.
“This new test has significantly reduced the waiting times for testing results, which will benefit ongoing surveillance for the bacteria,” he said.
Potato Growers Australia WA executive officer Simon Moltoni said the disease couldn’t be eradicated and so the response had moved to how best to manage it.
He said the recent experience had pointed out that the industry needed reassurances from growers that they have the best on farm biosecurity practices and that the national biosecurity measures were not foolproof.
“This disease (Dickeya dianthicola) was not on any list (in WA).
“Growers met all the requirements,” Mr Moltoni said.
“They had been very cautious and fulfilled their duty of care.
“But it still came in – which shows there is a loophole somewhere in the national system.”
