Good season brings disease challenges
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SOUTH Australian grain growers are being urged to stay alert to disease threats building in crops despite the promise of a good season.
SARDI researcher Hari Dadu and Hart research intern Molly Edmondson will highlight the importance of disease management, clean seed and variety choice when they present at the Hart Field Day on Tuesday, September 15.
“We are receiving a lot of disease enquiries at the moment, especially if I’m looking at pulses and cereals in general,” Mr Dadu says.
Ascochyta blight has been reported across lentil-growing regions, while botrytis grey mould has been detected in parts of Yorke Peninsula and sclerotinia white mould on Eyre Peninsula.
Cercospora leaf spot and chocolate spot have also been detected in faba beans, while disease concerns are emerging in cereal crops, including net form net blotch and leaf rust in barley and powdery mildew and stripe rust in wheat.
“We have seen ascochyta blight in the Mid North and we have seen cercospora leaf spot and chocolate spot in faba beans,” Mr Dadu says.
For lentil growers, one of the key messages is the importance of starting with clean seed. Research at Hart is examining the impact of lentil seed quality on ascochyta blight, including seed treatments and foliar fungicides.
“The trial is looking at ascochyta blight in lentils and comparing when we’ve got infected seed — with a known infection of 85 per cent — to clean seed,” Ms Edmondson says.
“We’re seeing how different fungicide treatments compare and trying to work out what the best approach is when you do have some known infection in your seed.”
Mr Dadu says seed health is critical because seedborne infection is one of the main pathways for ascochyta blight, making seed quality testing an important tool for reducing disease risk.
“The threshold level is so low, because if you have two per cent or more disease in the seed, then you’re propagating disease and passing to the next season,” he says.
The trial is also examining whether seed treatments can help maintain plant establishment where infected seed is used, with early results in pot trials indicating a seed treatment provided at least a 10 per cent benefit in plant retention per square metre.
As the 2026 Hart research intern, Ms Edmondson has been working closely on the ascochyta blight in lentils research and says the Hart Field Day is a good opportunity to see the trial and learn more about identifying and managing disease.
The disease challenge will also be explored by SARDI researcher Tara Garrard, who will provide an update on barley net form net blotch and cereal disease.
A GRDC-funded project, supported by Hart, is examining integrated disease management strategies for net form net blotch, which Mr Dadu says has become increasingly damaging over the past four to five years.
Of particular concern is the emergence of fungicide resistance, with researchers recently identifying a net form net blotch isolate carrying mutations associated with resistance to three fungicide groups.
“We are running out of options in terms of fungicides and we just have to quickly understand what is important and what is the easiest way of managing net form net blotch,” Mr Dadu says.
“The easiest way that we can think of is choosing the right varieties.”
Mr Dadu, Ms Edmondson and Ms Garrard will join researchers and industry experts presenting the latest research and seasonal insights at the Hart Field Day on Tuesday, September 15.
Admission is $45 (students $15), including access to all rolling sessions, guest speakers and a Hart Field Day Guide.
The Hart trial site is 10 kilometres north of Blyth, just off the Blyth to Brinkworth Road.
For tickets or more information, head to hartfieldsite.org.au and look for Events/Hart Field Day.
