Growers are encouraged to be more vigilant in the detection and control of wheat leaf, barley leaf and wheat stripe rusts as all three have recently being found in Victorian cereal crops.
Agriculture Victoria Plant Pathology Senior Research Scientist Dr Grant Hollaway is advising growers and consultants to inspect their cereal crops for symptoms to determine if they need to apply foliar fungicides.
“Growers should check the latest disease resistance ratings in the Victorian Cereal Disease Guide to identify which varieties are the most vulnerable to infection,” Dr Hollaway said.
“If conditions continue in favour for rust development, these diseases have the potential to cause more than 50 per cent yield loss in susceptible varieties.
“Wheat stripe rust is also expected to develop rapidly in crops during the next six weeks as temperatures increase.”
Dr Hollaway said it was important to note that many adult plant resistance (APR) genes are less effective during cooler conditions, providing less protection in the advanced early sown crops.
“Since the detection of a new wheat leaf rust strain in Victoria in 2014, many varieties are now more susceptible to the disease than before. Growers therefore need to be more vigilant with its control,” he said.
“Fungicide application may be necessary in some cases. Since leaf rust prefers warmer temperatures than stripe rust, leaf rust is not expected to increase quickly until October.”
Barley leaf rust has been identified in the Mallee and Wimmera this season and will affect most barley varieties. Growers should check resistance ratings and monitor crops accordingly.
Dr Hollaway is encouraging any growers who find rust to send a sample to the Australian Cereal Rusts Survey to help researchers understand the distribution of rust species and whether any new pathotypes have emerged. More information can be found on the Rust Bust website.
Agriculture Victoria and the Grains Research Development Corporation work together on research into rust diseases.
Read a more detailed article about rust diseases authored by Dr Holloway.
Source: Agriculture Victoria. Download the Victorian Cereal Disease Guide