Stripe Rust Already An Issue For Central Washington Fields

Washington State University is forecasting stripe rust in the upper range of severe epidemics for the "eastern" Pacific Northwest.  WSU says 40-60% yield losses are possible for  susceptible varieties in the coming season.

Strips rust has already been reported in winter wheat fields in Washington’s Lincoln, Adams and Franklin counties.  Rust incidence and severity were more in the south than the north.

WSU's Xianming Chen said a fungicide application is recommended for the winter wheat fields planted with moderately resistant to susceptible varieties with stripe rust ratings 3 to 9 at the time of herbicide application, and a second application may be needed 20 to 30 days after the first application, which can be determined by whether active stripe rust appears in the field after the first application.

Next Steps For Washington Wheat Growers

As many resistant varieties (stripe rust ratings 1 and 2) have only high-temperature adult-plant (HTAP) resistance, which will not be effective until the weather gets warm and plants reach the middle jointing stage (Feekes 7), stripe rust can develop on these varieties.  Chen said any wheat fields should be checked for stripe rust. If active rust is found, fungicide should be applied at the timing of herbicide application.

Refer to 2026 First Stripe Rust Forecast for the Eastern Pacific Northwest for stripe rust ratings of wheat varieties.  For spring wheat, resistant varieties (stripe rust ratings 1 or 2) should be selected for planting.

Chen said if for any reason varieties in the other categories (stripe rust ratings 3 to 9) are going to be planted, fungicide application will be likely needed at the time of herbicide application.

To help growers select the right fungicide for their operation, WSU has developed this Table which has active ingredients, application rate, control effect, effective duration, total limit per crop, and stage or date of application restriction.

Stripe Rust Reported Across The Country

in addition to stripe rust being reported in central Washington, it was also reported in the Pendleton, OR area on January 27, outside of  Davis, CA on February 9, and in central Texas on January 12.

Chen noted the observations of stripe rust in the Davis area of California were also unusually earlier than normal.  The occurrence of stripe rust in Texas in January is an indication of severe epidemic in the southern Great Plains and potentially epidemics in the central and northern parts of the Great Plains.

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