Blueberry farmers faced challenging news last week as Tasmania abandoned containment rules for a fungal fruit infection, but new research may provide a solution to organic growers.
The fungal disease - which can cause severe defoliation, stunted growth and plant-death - was previously regulated as a serious threat to crops and required infected farms to cease trading to limit the spread.
But a technical review panel of Biosecurity Tasmania, industry stakeholders, farmers and interest groups concluded that the state's strict containment plan was no longer effective and would only inhibit local producers from accessing domestic markets.
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While treatment options exist for non-organic growers, organic farmers are armed with less straightforward mitigation methods, something that Tasmanian Institute of Agriculture associate professor Kara Barry hopes to change.
What solutions are there?
"There are positives in deregulating for organic growers in that any that were infected premises can now sell within Tasmania, and a lot of the smaller growers do have quite a big Tasmania and local market as part of their business," professor Barry said.
The challenge for organic growers now, she said, was navigating export laws like the ones in South Australia, that require growers to spray their crops with copper or other chemical compounds to protect crops from the fungus.
"The research that we're doing is trialing a range of organic products. We've got one that seems to be standing out to be better as a more consistently effective product," she said.
Polyoxin-D, or Intervene, has shown promise as an organic option that, while not as effective as chemical alternatives, could suppress fungal outbreaks.
Although only recently developed, researchers at TIA believe the product could warrant certification as an organic fungicide if it continues to show positive results.
The only catch is in how it's delivered.
Professor Barry said Intervene's active ingredient was only deliverable as 'wettable granules' that required chemical compounds, rendering the product unsuitable for organic certification.
"We hoped it would become available as an organic product. It isn't at the moment, however, we could still hopefully get a minor use permit for it".
So what's next?
Tasmanian chief plant protection officer Andrew Bishop said with a large number of cases recorded last season, deregulation of blueberry rust containment was a logical step that would reopen the door to domestic markets for organic farmers.
"We ended up with the perverse situation that producers with blueberry rust could actually send their product to any state in Australia but not move it within Tasmania," Mr Bishop said.
"A number of these businesses had existing markets, then suddenly we said, well, you can't trade into them and you can imagine for struggling small business that's massive,"
"If we'd maintain the current position this next season, we'd have seen more spread and effectively we could have ended up with a majority of producers basically being regulated out of business".
But the changes also mean scientific trials can be run domestically without fear of being shut down by containment rules.
With the support from the Tasmanian government, professor Barry said a three year trial beginning next year will see TIA research non-fungicide and non-spray options for rust management.
Next year will also see local grower workshops, and on-property defoliation trials and the establishment of weather stations on farms to capture microclimate data.
"Defoliation may be a useful tool to break the disease cycle in evergreen and semi-deciduous varieties, if it does not reduce yield too much," she said.
