Western Australia
August 20, 2013
Stem rust on wheat.
The Department of Agriculture and Food is reminding wheat growers to monitor crops for stem and leaf rust following several reported cases in the central and southern Wheatbelt.
Stem rust has been found at low levels in a Halberd wheat hay crop growing near Varley. Early sown Yitpi crops may also be at risk in these areas.
Leaf rust has been confirmed on crops of the susceptible wheat variety Stiletto from Kondinin and Karlgarin and on the moderately susceptible variety Yitpi at Hyden. Other reports have been received of leaf rust infected Stiletto crops in surrounding areas and from the lower great southern.
Department plant pathologist Kith Jayasena advised growers in these areas to keep a close watch on their wheat crops for potential early appearance of both stem and leaf rusts.
“Early sown varieties that are known to be susceptible to either of these rusts will need closest attention,” Dr Jayasena said.
“The timing of fungicide application is important as early application at first rust detection in susceptible varieties will provide the greatest yield benefit.”
Previous trials conducted by the department in the Esperance area indicated that stem rust can reduce yields in susceptible and partially susceptible varieties by 10 to 53 per cent. Severe rust pressure can result in losses of up to 90 per cent on susceptible varieties.
“If any stem rust is detected before head emergence, growers are advised to spray susceptible and moderately susceptible crops as soon as possible with an appropriate fungicide at a high rate,” Dr Jayasena said. “For crops with intermediate resistance, continue to monitor and spray if infection exceeds an average of five per cent of random stems infected.”
More information on wheat rust management from the Farmnotes: ‘Managing stem rust of wheat’, ‘Managing strip rust and leaf rust of wheat’ and ‘Foliar fungicides registered for use on wheat in WA – 2013’ is available online at www.agric.wa.gov.au.
Information on susceptible wheat varieties is available from the ‘Wheat variety guide for WA 2013’, also online.
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