NSW grain growers have been urged to send wheat stripe rust samples to the Australian Rust Survey following confirmation of a new strain of the fungus which causes the disease at two sites in Victoria’s Mallee and Wimmera regions.
NSW Department of Primary Industries (DPI) rust diseases plant pathologist, Will Cuddy, said the new pathotype was the first detected case of wheat stripe rust virulence in Australia for the resistance gene Yr33.
“Yr33 has been used to breed stripe rust resistant wheat varieties, including EGA Gregory, and these previously resistant wheat varieties are potentially less resistant to the new pathotype,” Dr Cuddy said.
“Wheat varieties which were considered susceptible to the existing and widespread stripe rust pathotype 134 E16 A+ 17+ are also likely to be susceptible to the new strain.
“This season we advise growers to monitor EGA Gregory, Coolah, LRPB Flanker, Axe, B53, Buchanan, Cobalt, EGA Gregory, Forrest, Gauntlet, Grenade CL Plus, Mitch, Steel, Trojan, Viking and Zen.
“By tracking wheat stripe rust in the 2018 crop we hope to keep an eye on the new pathotype and develop appropriate strategies to manage crops.”
Field results from Agriculture Victoria at Horsham suggest the new strain is also the first case of virulence for an identified, but as yet uncharacterised, adult plant resistance gene in wheat.
Wheat stripe rust, caused by the fungus Puccinia striiformis f. sp. tritici, can result in up to 70 per cent yield losses in susceptible wheat varieties and needs a living host, typically wheat and barley grass, to survive.
Spores from the fungus are spread by wind, but they can also be spread on clothing and vehicles that have moved through infected paddocks.
NSW DPI advises growers to be mindful of biosecurity protocols, come clean- go clean, to limit the spread of pests and diseases.
Samples of stripe rust found on any wheat variety should be sent in paper packaging, not plastic, to the Australian Rust Survey, University of Sydney, Reply Paid 88076, Narellan, NSW 2567.
NSW DPI and the University of Sydney have collaborated on stripe rust diagnostics and research since 1980 and latest Cereal Rust Report is available online.
The Australian Rust Survey was funded by the Grains Research and Development Corporation.
Source: NSW DPI