The wheat disease stripe rust has been found in a handful of isolated areas of the Pacific Northwest.

The fungus was found on “isolated hotspots” on UI Magic in Morrow and Gilliam counties in Oregon, and two commercial fields near Walla Walla, Wash.

It was also found at low levels in experimental fields near Pullman, Central Ferry and Walla Walla, said Xianming Chen, USDA Agricultural Research Service plant geneticist.

Recent conditions have been favorable for stripe rust development, said Christina Hagerty, assistant professor of cereal pathology at Oregon State University.

“Late arrival of rust this year is good news for growers,” she said. “The earlier rust arrives in the season, the bigger dent it typically makes on yield.”

For highly susceptible varieties, such as UI Magic and Mary, it is best to spray when rust is first found rather than wait for flag leaf emergence, Hagerty and other OSU researchers said in a recent alert to growers.

Farmers should be prepared for a second spray, Hagerty said in the alert.

“Rust is never a disease to chase,” she said. “We need to stay on top of it with timely applications in infected fields of susceptible varieties.”

In his report, Chen recommended fungicide application for susceptible and moderately susceptible varieties of winter wheat before the flowering stage.

He also advised farmers to check fields planted to moderately resistant varieties.

“Growers should check fields immediately in southcentral and central Washington, Oregon, and southern and central Idaho for stripe rust,” Chen said in a report. “Fields in the Palouse region of Washington and Idaho and farther north should be checked starting about (May 22).”

UI Magic is known to be susceptible to stripe rust. During years of disease pressure, growers should utilize fungicides, said Hannah Kammeyer, Pacific Northwest regional commercial manager for Limagrain, which developed the variety with the University of Idaho.

Limagrain is releasing two new Clearfield wheat varieties with improved stripe rust tolerance in collaboration with UI — VI Voodoo and VI Presto. Certified seed will be available this fall, Kammeyer said.