Australia
August 31, 2012
Cereal disease authorities are urging grain growers to closely monitor crops following an acceleration in reports of stripe rust in wheat.
Disease experts, supported by the Grains Research and Development Corporation (GRDC), say growers should also be considering implementation of rust management plans to reduce the risk of yield loss.
As temperatures rise, reports of stripe rust are likely to become more widespread over the coming weeks.
Stripe rust has been reported in crops growing in central and western Victoria, as well as in many parts of South Australia, including Eyre Peninsula, the Mallee and Lower and Mid North regions.
Stem rust of wheat has also been found on volunteer wheat growing in the Victorian Mallee, serving as a reminder that there has been some carryover of this disease. Stem rust is favoured by warm and humid conditions and is therefore likely to be observed in crops from mid spring, especially following a wetter than average spring.
Australian Cereal Rust Control Program (ACRCP) Consultative Committee chairman Grant Hollaway says monitoring of crops is vital in thwarting the potential for significant crop losses due to rust.
Dr Hollaway says growers can monitor crops by visually assessing thicker patches and by walking through a paddock to get a more accurate assessment of the whole crop. Growers should inspect the lower parts of the plant, the stem and the leaves for rust symptoms.
“Timing is critical for the effective control of rust diseases with fungicides. Varieties that are Susceptible (S), Moderately Susceptible (MS) and Moderately Resistant to Moderately Susceptible (MR-MS) will need to be monitored regularly if fungicide protection has not been applied at sowing,” Dr Hollaway said.
“In these cases, fungicide application should be considered at the first appearance of symptoms. Monitoring should then continue, as protection periods following foliar fungicides will vary according to chemical product and growth rate of the crop.
“Varieties that are S and MS will need further protection where there is early detection of rust.”
Dr Hollaway recommends that growers who are not sure how susceptible their varieties are, or which is the best approach to take, check with their local agronomist, plant pathologist, regional variety guide or visit the Rust Bust website at www.rustbust.com.au.
The Rust Bust campaign was launched last year by the ACRCP Consultative Committee to encourage growers to be proactive and plan their rust management strategy early in response to what was the worst disease risk in nearly 40 years.
Supported by the GRDC, the Rust Bust gives growers tips on effectively managing rust and adopting a ‘select and protect’ strategy.
“Variety selection along with disease management is crucial in minimising disease risk because a rust outbreak can slash grain returns by more than half,” Dr Hollaway said.
“The ultimate goal of the campaign is to encourage growers to phase out susceptible and very susceptible varieties from their rotation where possible but if these cultivars are grown, then farmers need a management plan ready in advance in case of a rust outbreak.”
In the meantime, growers who detect or suspect rust infection in their crops should notify their neighbours so they too can manage rust in their crops.
Authorities say disease reporting and sample collection is important, enabling the grains industry to maintain awareness of outbreaks and spread. Growers and advisers should send leaves or stems carrying suspected rust infection, in paper envelopes, to: Australian Cereal Rust Survey, Plant Breeding Institute, PO Box 4011, Narellan, NSW 2567.
Sample information (location, variety if known, date) and collector’s contact details (preferably an email address so results can be reported) should be included with the sample.
More information about cereal rust prevention and management strategies is available from the Rust Bust website, www.rustbust.com.au, or via the GRDC’s cereal diseases online information hub, www.grdc.com.au/rustlinks.
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