Ever been to a rugby match and thought, how the heck does that ball get from one end to another?
Big stocky men, built like bricks, standing in the way. But sure enough, it does.
Forming a backline, the ball slowly moves forward, even though it’s being passed behind. So much pushing and shoving by those forwards, until eventually, the ball crosses over the line for a try.
How does this happen? By being very, very strong.
But more so than that, by working together.
This is the idea behind CCDM’s latest project. We’re calling on barley growers to work with us on our new Barley Disease Cohort Project – a pilot project aiming to engage farmers from the South of the WA Wheatbelt in fungicide resistance research.
We’re building up a large rugby team to tackle a big and stocky issue in the South of the WA Wheatbelt – where both net-form and spot-form net blotches are now fungicide resistant to three active ingredients within Group 3 DMI fungicides.
The current spot-form net blotch (SFNB) situation
CCDM researchers have been hard at work analysing over 470 samples of SFNB collected in WA between 2016 and 2018. They found strains collected from South Stirling and Esperance to be highly resistant to active ingredients tebuconazole, propiconazole and prothioconazole (marked in red on map below), and many other strains to be moderately resistant (marked in yellow on map below).
Leader of this research Fran Lopez-Ruiz said the difference between highly and moderately resistant strains was down to the type and number of mutations at SFNB’s fungicide target gene.
“Without getting into the detail of our mutation detection work (stay tuned for that detail next month), we now know that growers with highly resistant spot form net blotch will see fungicide failure in the field,” he said.
“However we’re not sure if growers with moderately resistant SFNB will see fungicide failure, as we have not received reports from the field confirming this yet.”
The current net-form net blotch (NFNB) situation
CCDM researchers were also studying NFNB strains over the same period and were able to classify NFNB as moderately resistant against the same three active ingredients tebuconazole, propiconazole and prothioconazole (marked in yellow on the map below).
They also found strains that were highly resistant, with these strains needing far more fungicide to destroy them (marked in red on the map below).
Fran said just like with SFNB, growers with highly resistant NFNB on their properties will experience a reduction in disease control, but until further research was carried out, he was unsure whether growers with moderately resistant NFNB will see a similar trend in the paddocks.
He said fungicide resistance was a complex process that develops over time in response to chemical inputs, but also crop type, climate and farming practice.
“The early stages of development of resistance to one chemical within a fungicide group may not always negate the future use of that chemical or other chemicals within the group if applied strategically,” Fran said.
“However, at this time we have not got enough empirical in-field data to support profitable long term strategies for managing fungicide resistance, which is why this cohort project is so important.”
Fungicide tips for managing net blotch this season:
- Only spray if necessary – limit applications
- Do not exceed label rates
- Choose mixtures with different modes of action (if available). Overuse of fungicides with the same mode of action will speed up fungicide resistance
- Ideally use DMI-based mixtures (e.g. Prosaro® containing prothioconazole and tebuconazole) only once, followed by mixtures containing other actives (preferably from groups 7 or 11)
- Never apply the same Group 3 fungicide twice in a row. Avoid applying the same mode of action fungicides from the Groups 7 and 11 twice in a row
- Incorporate the use of seed dressing (Group 7), in-furrow (Group 11) and foliar products containing fungicide mixtures from different chemical groups (such as 3 (DMI), 7 (SDHI) and 11 (Qol)) – in combination with limited use of propiconazole and no stand-alone tebuconazole use.
- Avoid using tebuconazole as a stand-alone product in barley for any disease to avoid indirect fungicide resistance selection
- If resistance is present, or suspected, avoid or minimise use of that mode of action – this will only further select for resistance
Join the cohort and help us beat the blotch
Led by our cereal disease researcher, Lorenzo Covarelli, with input from Fran and our director Mark Gibberd, we’re building a cohort of growers to help find out exactly where resistance is occurring in the South of the WA Wheatbelt, and will carry out local field trials to find solutions to managing the growing problem.
Are you a barley grower from the South of the WA Wheatbelt? Join us! Cohort members will work with CCDM by:
- Sending in diseased barley leaves for fungicide resistance research.
- Answering survey questions on management decisions.
- Being part of a cycle of co-innovation with CCDM researchers in helping to find solutions to managing fungicide resistance.
It’s a yearly cycle of co-innovation:
Year 1 Join the cohort and send in diseased barley leaves for research purposes
Year 2 Results from year 1 will allow for better decisions
Results from year 1 will spark field trial ideas
Year 3 Results from year 2 will allow for better decisions
Results from year 2 will spark field trial ideas
And so on!
Register your interest or get more information by contacting cohort co-ordinator Megan Jones at megan.d.jones@curtin.edu.au.
