Look out for wheat rust as temperatures rise

Author: Natalie Lee | Date: 19 Aug 2015

Image of Wheat stripe rust

Several cases of rust in wheat have been reported in Western Australia and growers are encouraged to monitor crops carefully as temperatures rise, which can favour development of rust diseases.

Department of Agriculture and Food (DAFWA) plant pathologist Geoff Thomas said growers should check crops carefully, as managing rust at low levels in a crop was far more effective than when it was well established.

Mr Thomas, who leads a crop disease project conducted by DAFWA and supported by the Grains Research and Development Corporation (GRDC), said seasonal conditions had favoured the development of wheat rust, as well as other diseases including powdery mildew, barley leaf rust and sclerotinia.

“Reports of wheat rust made to the DAFWA newsletter PestFax include stripe, leaf and stem rust, which can all significantly reduce wheat yields on susceptible varieties, given appropriate environmental conditions,” he said.

“Stripe rust - which has been found on susceptible varieties Calingiri and Bonnie Rock in the eastern grainbelt this year ­has been very rare in WA over the past few seasons.

“Stem rust has been reported at just a couple of locations in wheat regrowth in central, eastern and northern areas.

“Leaf rust has been detected at low levels in the popular wheat variety Mace in crops across the grainbelt.”

Mr Thomas said a new leaf rust pathotype was first detected in WA in 2013 and if this pathotype was present in infected crops, Mace would be moderately susceptible to the disease.

Other wheat varieties with increased susceptibility to this leaf rust pathotype included Corack, Emu Rock, and Wyalkatchem.

Mr Thomas said these reports were a timely reminder to keep an eye out for the presence of rust.

“Monitoring priorities include wheat varieties susceptible to rusts and crops in areas where regrowth wheat has been allowed to mature,” he said.

“Remember to look into the bottom of the crop canopy and stems, to check for the presence of stem rust.

“Fungicides that may have already been applied for powdery mildew are also effective on leaf rust, and will restrict the progress of rust if it is present in the crop.”

Information on the susceptibility of varieties to rust is available from the 2015 Wheat Variety Guide for Western Australia, available at the DAFWA website by searching ‘wheat variety guide’.

Information on developing a rust management strategy can be found on the Rust Bust website, which includes a ‘Rust Bust Management Checklist’.

If rust is detected on crops, samples should be sent to the University of Sydney Plant Breeding Institute for pathotype analysis.

Rusted plant samples can be mailed in paper envelopes (not plastic wrapping or plastic-lined packages) to the Australia Cereal Rust Survey Plant Breeding Institute, Private Bag 4011, Narellan, NSW, 2567.

The Australian Cereal Rust Control Program (ACRCP), based at the University of Sydney, is one of the GRDC’s core investments to monitor, assess and develop a rust management strategy for Australian growers.

GRDC Project Code DAW00229, USU00067

Region West