What’s Happening?
Queensland researchers have found evidence that barley seeds can carry fungicide-resistant disease into developing crops.
Scientists at the University of Southern Queensland (UniSQ) discovered that net blotch can move from infected seed into seedlings.
The findings reveal a previously unrecognised pathway for fungicide resistance to move between crops and seasons.
Why It Matters
The discovery raises an important question for Queensland barley growers: could their planting seed introduce fungicide-resistant disease into a new crop?
Researchers found evidence that net blotch can move from seed to seedlings. This suggests growers may need to consider seed source alongside existing disease-management practices.
However, the findings also raise questions about how widespread the problem is and whether seed testing could help identify lower-risk planting material.
Lead researcher Dr Noel Knight said the discovery introduced another consideration for growers.
“Seed isn’t just planting material. It can be a disease-management decision,” Dr Knight said.
Local Impact
Net blotch is one of Queensland’s economically important barley diseases. It can reduce grain yields and create additional challenges for growers.
The research examined barley seedlots from grower fields across the Darling Downs.
While the findings highlight a potential risk for Queensland barley production, researchers still need to establish how often seed-to-seedling transmission occurs.
For now, the discovery adds to existing knowledge about disease management rather than changing current recommendations.
By The Numbers
- 16 seedlots: Researchers examined barley seed from grower fields across the Darling Downs.
- 13 seedlots: The number in which researchers detected net blotch pathogen DNA.
- $190 million: The approximate annual contribution of Queensland’s barley industry to the state economy.
Zoom In
Researchers investigated whether the barley seed carried markers linked to reduced sensitivity to fungicides.
They then planted one of the higher-risk seedlots and monitored the developing seedlings.
The team subsequently detected the same reduced-sensitivity types in net blotch lesions on those seedlings.
This provided evidence that fungicide-resistant net blotch can move from seed into the next crop.
Importantly, three seedlots showed no detectable net blotch. This suggests researchers may be able to identify lower-risk planting seed.
Zoom Out
Growers currently manage net blotch through several established methods. These include choosing less-susceptible barley varieties, reducing disease inoculum and rotating or mixing fungicides.
The new findings suggest seed source could become another consideration when managing the disease.
However, growers cannot currently access seed testing for net blotch and fungicide resistance.
The study forms part of the Broadacre Cropping Initiative, a joint investment by UniSQ and the Queensland Department of Primary Industries.
What To Look For Next?
The researchers are preparing their findings for publication.
Further studies will examine how widespread seedborne fungicide resistance is and how often transmission occurs across seasons. Researchers will also investigate how environmental conditions influence the process.
Dr Knight said the findings add another consideration rather than replacing existing disease-management advice.
“Rather than sounding the alarm, we’re adding another piece to the puzzle and giving growers another consideration to manage disease risk.”
