Potato Mop-Top Virus Spreads to Six Tasmanian Sites, Prompting Seed Stock Testing Push
Potato mop-top virus (PMTV) has been confirmed at four additional properties in Tasmania, bringing the total number of affected sites in the state to six.
Biosecurity Tasmania, which first announced the detection on August 13, said the virus had not previously been identified in Australia and may have been present in Tasmania for up to two years. The latest cases include properties in the north and north-west of the island, as well as a small research plot in the south. Two detections were made in seed potatoes, and four of the sites are directly linked.
PMTV, which is spread through soil and affects tuber quality, causes rust-coloured arcs in potato flesh. While not harmful to consumers, it can reduce yields and compromise the processing quality of potatoes, much of which in Tasmania is destined for the frozen goods sector.
In response, Biosecurity Tasmania has imposed restrictions on the movement of potatoes, machinery and equipment at the affected properties.
“Biosecurity Tasmania has been undertaking tracing activities associated with the detection and, in collaboration with industry, has expanded general surveillance efforts to sampling and testing seed potatoes currently held in storage,” the agency said in a statement.
“All potato growers need to remain vigilant for any signs of disease in potato plants and potato stock.”
With planting due to begin by the end of September, industry leaders have called for rigorous testing of seed stock. TasFarmers chief executive Nathan Calman said: “The concerning thing moving forward is that we now need to test all lines of seed potato ahead of the upcoming planting season to make sure that producers have confidence that what they put in the ground isn’t going to inadvertently spread the virus, or put their crops at risk.”
He added that it was positive that tracing efforts had been effective so far, but the long-term impact remained uncertain. “What’s not known is how it will interact with potato production in the Tasmanian landscape and climate.”
Susannah Driessen, Tasmania’s chief plant officer, said the immediate focus was on tracing and containment. “In acknowledgement of how close we are to planting, and the availability of seed potatoes to test, we’re doing a general surveillance approach in collaboration with industry,” she said.
She urged property owners to be cautious in handling soil and plant material. “Some of the risk associated with moving the virus is particularly with soil,” Dr Driessen said. “If you’ve got equipment, ensuring that they are absolutely cleaned down, not moving soil off the property, not moving plant material off the property. Really focused on keeping the virus where it is.”
