Grain growers are being warned to keep an eye out for a new pathotype of leaf rust, particularly if they grow Fitzroy and Yarra barley, after the first report of virulence for Rph3 in Australia.
The warning is contained in the latest Cereal Rust Report released by the Australian Cereal Rust Control Program, which is supported by growers through the Grains Research and Development Corporation (GRDC).
The new pathotype was identified from a leaf sample collected from experimental plots near Warwick in Queensland.
It is a mutation of a pathotype common in northern NSW and Queensland last year, where it reached epidemic levels in some crops of cv. Grout, and now combines virulence for Rph2 and Rph3.
Growers are also being urged to monitor wheat crops for stripe rust, with recent weather favourable to its development and early reports starting to filter in of outbreaks in commercial crops in northern New South Wales.