Rust Alert 6/4/10

Rust Alert

June 4, 2010

Xianming Chen

This is an urgent alert on stripe rust for wheat growers in eastern Washington, eastern Oregon, and northern Idaho. In the past week, there were many reports of stripe rust in the Pacific Northwest, except southern Idaho. Stripe rust has been found as north as near Davenport (Lincoln county), Washington. Severity levels range from low to significantly high depending upon varieties and locations.

The unusually highly frequent precipitations in the past two weeks have created the most ideal conditions for stripe rust infection. In the next two weeks, rust severities will increase rapidly on susceptible varieties. As temperatures have been so much lower than normal, HTAP resistance could not fully kick in. Varieties with moderate levels of HTAP resistance may need to be sprayed with fungicides.

Because most of labeled fungicides can only be used before flowering stage and the winter wheat crop have reached boot to flowering stage in the region, the next two weeks will be critical for stripe rust control. Please check your fields, apply fungicides if necessary.

If you have any questions, please feel free to contact me (office phone: 509-335-8086, cell phone: 509-432-5852, e-mail: xianming@wsu.edu) or Dr. Kent Evans (phones: 509-335-4789, 509-335-8715).