Stripe Rust Forecast: Potential for a Severe Outbreak This Year

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Note the yellow-orange urediniospores of stripe rust on winter wheat leaves in this image. Pustules are typically long and narrow, which differs from the scattered, individual pustules of leaf rust and stem rust.

Stripe rust is continuing to develop on winter wheat across the region, due to weather conditions that favor rust infection and spread. In Whitman County, Washington, stripe rust is about one month earlier than normal and similar to the severe epidemic years of 2011 and 2016. Growers should be scouting all winter wheat fields and may want to use a fungicide with their herbicide application if their wheat variety is moderately susceptible or susceptible, based on the rating in the Seed Buyers Guide. They should also treat their winter wheat if stripe rust is found on 2-5% of the plants in a field. Be sure to plant spring wheat that is resistant to stripe rust as well.

Additional rust updates will be released as the growing season continues and conditions change. You can find additional information on stripe rust, including photos showing rust percentage, under Foliar Fungal Diseases in the Disease Resources section of the WSU Wheat and Small Grains website.  Source: http://smallgrains.wsu.edu/stripe-rust/

For questions or comments contact Tim Murray by email (tim.murray@wsu.edu), by phone (509) 335-7515, or Twitter (@WSUWheatDoc). For additional information contact Dr. Chen at xianming@wsu.edu or (509) 335-8086; or Mike Flowers at (541) 737-9940 or at Mike.Flowers@oregonstate.edu.

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