Biosecurity Tasmania is undergoing investigations after a potato disease known as mop-top virus was detected in Australia for the first time.

The virus was found on a farm in north-west Tasmania, after being confirmed by diagnostic testing.

Biosecurity Tasmania’s chief plant protection officer Susanna Driessen told media that a farmer had alerted authorities earlier in 2025, and the authorities were now working to find out how far spread the virus may be.

“We are working with the grower to understand where material might have moved and also how material came onto the property,” she said according to news.com.au.

“This constitutes the first detection of mop-top virus in Australia, it may not represent the site of introduction.

“We’re quite early in the stage of this detection. What we’re doing at the moment is working with industry, working with the grower to understand where material might have moved and also potentially how material came onto the property.”

Mop-top virus comes from exotic plants and can be transmitted via a soil-borne fungus vector call spongospora subterranea which can cling to machinery and other materials. This pathogen can cause powdery scabs in potatoes, in turn reducing the vegetable’s quality and crop yields. The affected potatoes become distorted and the skin can crack with rust coloured arcs, streaks or flecks that can be seen in the flesh. That being said, the affected potatoes are still considered safe for human consumption, and there are no risks to food safety or human health associated with mop-top virus.

Risk mitigation measure have sine been put in place on the to attempt to contain the disease on the affected farm, but no wider restrictions have been put in place on the industry.

According to abc.net.au TasFarmers chief executive Nathan Calman said the detection was very concerning, and he called for a swift and strong response plan.

“It probably represents a significant failure in our biosecurity protocols,”  Mr Calman said.

“We need to contain the outbreak to the single farm it has been detected on.”

Tasmania’s Minister for Primary Industries Gavin Pearce – who is also a potato farmer on the state’s north-west coast – said an incident management team had been created, and that he wanted the issue dealt with immediately.

According to abc.net.au Tasmania produced the most potatoes during the 2023/24 season, with up to 479 thousand tonnes of the vegetable being grown.