Yield losses of up to 80 per cent if cereal diseases take hold

Farmers are urged to be aware of cereal diseases threatening their crops, with recent rain and heavy stubble loads promoting a higher presence of the diseases.

While farmers are emptying the rain gauge, they are also cautious about the threat of yield-robbing disease to crops.

Heavy stubble loads and recent rain have created conditions that can promote a higher presence of cereal diseases.

One of the culprits, crown rot, can reduce yields by 80 per cent when high infection rates occur.

NSW Department of Primary Industries cereal pathologist at Tamworth, Steve Simpfendorfer, said fusarium crown rot was a major disease threat for both wheat and barley.

He said in cases where there was high levels of infection from crown rot durum wheat varieties could experience yield losses of 80 per cent.

“In bread wheat varieties, you might see 60 per cent losses, and barley yield losses can be up to 40 per cent,” he said.

Mr Simpfendorfer said last season, there were some of the highest levels of crown rot in cereal crops that he had seen in his 25-year career.

“We have had a run of good seasons … there is a high amount of stubble and biomass,” he said.

The biomass and stubble level were considered risk factors for crown rot.

Measurement techniques can be used, including testing the amount of fusarium crown rot in stubble.

An example of crown rot in a cereal crop.

Mr Simpfendorfer said that NSW DPI monitored 663 samples, and it was found that they had high to very high levels of infection.

Rain has arrived to deliver what is considered an ideal autumn break.

However, the wet weather is adding to the risk of cereal diseases.

Data from the Bureau of Meteorology tallying the seven-day rainfall for NSW townships shows Narrandera had 60mm, Griffith 3mm, Cobar 11mm, Coonabarabran 46mm.

Brad Baxter of NSW DPI, Wagga Wagga, said there had been reasonable rainfall post-harvest.

He highlighted his concerns about cereal diseases on the NSW DPI Agronomy podcast hosted by NSW Department of Primary Industries project officer, northern cropping systems, Penny Heuston of Warren.

Mr Baxter said there had been reports of crown rot in some early-sown oats to the east of Wagga Wagga.

“It is something to be aware of for anyone with early-sown oats,” he said.

Mr Baxter also urged growers to be on the lookout for stripe rust during the upcoming season.

“Our biggest risk with stripe rust is complacency; we are coming off some big (crop years), and it can be harder to control in those bigger cropping years,” he said.

In addition to stripe rust, there was also some septoria in crops last year.

“The risk, actually starts at the end of harvest, any remaining stubble from the 2022-23 crop is going to be a risk in 2024 if the pathogens survive,” he said.