First Stripe Forecast of the 2023 Season

Stripe rust figure 1.

Dr. Xianming Chen, USDA-ARS plant pathologist, is predicting stripe rust severity to be in the lower range of a moderate epidemic in his first forecast for the 2023 growing season released January 10. These predictions are based on air temperatures in November and December and equate to a yield loss of 0-15% for currently grown commercial varieties. This forecast is slightly better than the January 2022 forecast of 0-17% yield loss. Reduced severity is the result of colder temperatures during December 2022 compared with December 2021. Also recall that the 2022 crop season was an unusual year for stripe rust given that rust developed late in the season. Although the late appearance allowed the rust to develop and produce spores to infect the newly emerging winter wheat crop, very limited precipitation in September was not conducive to plant emergence or rust infection and there was limited rust development and overwintering.

Although this forecast is good news, there is a long way to go to harvest. Dr. Chen’s models don’t account for snow cover, and the rust potential going forward depends on snow cover and temperatures through the remainder of January and February. Given more time, Dr. Chen’s March predictions are typically most accurate and is when we will have a much better idea of late winter impact on survival of the stripe rust fungus.

Dr. Chen also included results of variety testing and fungicide efficacy studies in this report. I encourage you to take a look at his update as you are considering the best spring wheat varieties to plant and/or your fungicide program for this spring.

Stay tuned for more rust updates as conditions change. In the meantime, you can find additional information on stripe rust, including photos showing rust percentage under the Foliar Fungal Diseases and updated rust ratings for winter and spring wheat varieties in my presentation “Identification & Management of Winter Wheat Diseases: WSU/WI/WWCC Last Chance Pesticide Recertification, December 9, 2022” in the Disease Resources section of the WSU Wheat and Small Grains website.



Tim Murray.

For questions or comments, contact Tim Murray via email at, via phone at (509) 335-7515, or by following him on Twitter @WSUWheatDoc.