Stripe Rust is Developing on Susceptible Winter Wheat in Franklin County 4/26/03

April 26, 2003

Xianming Chen

I was checking wheat fields for stripe rust in southeastern Washington and northeastern Oregon on April 25. Stripe rust is developing on susceptible winter wheat varieties such as ‘Hatton’ in Franklin County. In winter wheat fields near Kahlotus, few stripe rust pustules were found. In several fields near Connell, more than 80% of wheat plants in the entire field had stripe rust with severity levels ranging from 15 to 30%. However, within the hotspots (rust foci) up to several hundred feet in diameter in these fields, 100% plants were infected, severities were over 60%, and grounds were covered with rust spores. Some fields were recently sprayed with fungicides. It was reported recently that stripe rust was occurring on early-planted spring wheat varieties in the Pendleton area of Oregon.

Such high level of stripe rust infection in the eastern Washington at this time of year has not been seen for many years. Because heavy rust inoculum is already in the region and the weather (frequent rains with wind and cool temperatures) has been very favorable to the disease and will continue being favorable for next 10 days, stripe rust will spread and develop in the eastern Washington. This year, stripe rust will occur on susceptible spring wheat much earlier than it did last year. Therefore, if you grow susceptible winter wheat varieties (such as ‘Hatton’, ‘Weston’, and ‘WPB 470’) or spring wheat varieties (such as ‘Zak’, ‘Challis’, and ‘Jubilee’), you should check your fields frequently and apply fungicides as needed.

If you have any questions on stripe rust, please contact Xianming Chen (Phone: 509-335-8086, Fax: 509-335-9581, E-mail: xianming@mail.wsu.edu).