Stripe rust has been found in commercial fields of winter wheat in Walla Walla, Benton, Grant, and Adams counties, said USDA ARS research plant pathologist Xianming Chen, Ph.D. in his second stripe rust forecast of 2016.
Chen and his team observed the foliar disease on less than 1% of the plants, and said it may be difficult to spot. Despite the low incidence, its presence coupled with cool and wet weather prompted him to predict potential yield losses of up to 26% on susceptible varieties.
Weather has an impact on stripe rust development. The possibility of a wet spring combined with the early detection of stripe rust are indicators that growers and consultants should be vigilant in their field scouting.
In many parts of the Pacific Northwest, now is the time to scout winter wheat fields for stripe rust. Should you find it or if you’re growing a susceptible wheat variety, consider including a fungicide with your herbicide application. If you have yet to plant spring wheat, look at planting a resistant variety and avoid planting varieties that are susceptible to stripe rust.
Take advantage of the Variety Selection Tool, which provides stripe rust ratings on most commercially grown varieties. Ratings of 5 to 9 indicate moderate to severe susceptibility, respectively.
Regional extension specialist Ryan Higginbotham (firstname.lastname@example.org or 509-335-1205) works with the WSU Cereal Variety Testing program. Extension plant pathologist Tim Murray (email@example.com or 509-335-7515) specializes in wheat diseases. Look for him on Twitter @WSUWheatDoc.