Stripe rust update 04/17: Pressure low in Eastern Washington

By Dr. Xianming Chen

On April 13 and 14, we were planting spring cereal nurseries and taking the first notes of the winter nurseries at Mount Vernon, Wash. The winter plants were at jointing stage ranging from Feekes 4 to 6. Wheat stripe rust was up to 60 percent severity on susceptible varieties. Barley stripe rust up to 40 percent severity was observed on susceptible varieties. Although barley stripe rust was relatively uniform and severe compared to this time of the last year, the severity of wheat stripe rust is normal for this location. 

On April 15, we were checking winter wheat fields in Benton County, Walla Walla County, Columbia County and Garfield County and in Umatilla County in Oregon. Winter wheat ranged from Feekes 3 to 6. No rust was found on wheat plants, but stripe rust was found on wild grass in our winter wheat stripe rust monitoring nursery at the Hermiston Station, Ore. No stripe rust was found in the monitoring nursery at Walla Walla, different from the observation of stripe rust at this location this time of the last year. 

Similarly, stripe rust was observed on wild grasses, but not on wheat plants in our winter wheat nursery and breeding nurseries at Central Ferry in Garfield County on March 30, when we were planting spring cereal nurseries. 

As stripe rust pressure is currently low in the eastern Pacific Northwest, fungicide application is not recommended in the early growth season for winter wheat, unless stripe rust is observed in fields. 

Stripe rust in the country 

In addition to Washington and Oregon, wheat stripe rust has been reported so far in Louisiana and Texas.