Fungicide resistance detected in Queensland barley

Early detection is key to keeping industry growing tall

They say knowledge is power, and early knowledge could be the key to keeping Queensland’s barley crops thriving.

That’s been the principal message out of research by University of Southern Queensland (UniSQ) Centre for Crop Health Senior Research Fellow, Dr Noel Knight.

Dr Knight has been conducting research monitoring for fungicide-resistant diseases in barley plants across southern Queensland, and the results have shown resistance is more common in Queensland than growers might have suspected.

“Fungicide resistance is generally only reported when there is a field failure,” Dr Knight said.

“But once you notice it in the field, it’s already a big problem.

“By that stage, a large shift in the pathogen population has already occurred and the issue is challenging, or even impossible, to control.”

To conduct his research, Dr Knight took net blotch disease samples from 10 barley fields across southern Queensland and analysed them using a DNA surveillance method.

Dr Knight investigated whether any of the genes responsible for fungicide resistance were present in the samples and, if so, how prevalent they were.

From the samples taken from 10 southern Queensland barley fields, Dr Knight was able to detect resistance genes for Group 3 fungicides in 34 per cent of the regional population, and up to 68 per cent in individual fields.

While this may seem concerning, Dr Knight said it was not cause for alarm. Rather, these results highlighted the importance of growers using this knowledge to their advantage and adjusting their strategies early.

“The emergence of fungicide resistance is a concern as chemical applications may become less effective at controlling fungal disease,” he said.

“If growers apply fungicides expecting a certain level of control, and that doesn’t occur, it may lead to unexpected yield and financial losses.”

Dr Knight likened the effects of fungicide resistance in barley to that of antibiotic resistance in humans. He said that was why it was important for growers to have a robust disease management strategy to maintain the effectiveness of each chemical in the field.

“Barley growers in Queensland currently have access to three fungicide groups for controlling net blotch disease, and losing the efficacy of even one group reduces disease management options and puts more pressure on the remaining groups to be effective,” he said.

“In the worst-case scenario, an entire fungicide group may be compromised.”

Dr Knight said growers with suspected or confirmed cases of fungicide resistance should consult with local and regional experts to gather the latest information for their region.

“The Australian Fungicide Resistance Extension Network (AFREN) is an excellent resource for regional contacts and management approaches,” he said.

UniSQ supported Dr Knight’s innovative research through a 2022 Capacity Building Grant.

Dr Knight’s research was conducted in collaboration with the Centre for Crop and Disease Management, the Queensland Department of Agriculture and Fisheries, and UniSQ’s Broadacre Cropping Initiative.

Learn more about the research from UniSQ’s Institute for Life Sciences and the Environment.

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