Early knowledge could be the key to keeping Queensland’s barley crops thriving according to 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 ten barley fields across southern Queensland and analysed them using a DNA surveillance method.

Of the ten barley fields, two were in Oakey, two in Yalangur and the rest in the Western Downs.

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 ten 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.”

This article appeared in On Our Selection News, 24 August 2023.