By Tim Murray (Reprinted from 2018) High-temperature adult-plant resistance, frequently referred to as HTAP resistance, is used widely in PNW winter and spring wheat varieties to help reduce the impact of stripe rust. This time of year, when we’re transitioning into warmer spring temperatures, is when I often get the question “how warm does it need to be for HTAP ... Read More »
By Dr. Xianming Chen USDA-ARS Since the last update on March 19, stripe rust of wheat has been developing fast in the Pacific Northwest, and many winter wheat fields have been applied with fungicides at the herbicide timing. We have been planting spring cereal nurseries and collecting stripe rust data from winter nurseries at some of the experimental fields. On April ... Read More »
By Dr. Xianming Chen On March 18, we were checking wheat fields in Franklin, Benton, Walla Walla, Columbia, Garfield, and Whitman counties. Wheat plants ranged from Feekes 3 to 6. Stripe rust was found in all counties. In Franklin County, stripe rust has developed quickly since the field check on March 3, forming rust foci (hot spots) of several feet in diameter. In Horse ... Read More »
From smallgrains.wsu.edu Weather data collected by USDA’s Dr. Xianming Chen from November 2025 to February 2026 indicate severe epidemic levels of stripe rust. Highly susceptible varieties could experience yield losses of 40-60%. Commercial fields will likely have yield losses between 8% and 40% without a fungicide application. Read the rest of the article here. Read More »
By Dr. Xianming Chen USDA-ARS Research Plant Pathologist Wheat stripe rust is forecasted to be in the upper range of severe epidemic (40-60% yield losses on susceptible varieties) in the 2026 growing season for the eastern Pacific Northwest, based on the predication models using the weather data from November 2025 to February 2026. The models predict highly susceptible varieties to have 55.8% yield ... Read More »
By Xianming Chen USDA-ARS Research Plant Pathologist Based on the weather data of November and December 2025, stripe rust in the 2026 wheat growing season is predicted to be in the upper range of severe epidemic level (40-60% yield loss on susceptible varieties). Using a set of forecast models based on the weather data of these two months, potential yield ... Read More »
By Dr. Xianming Chen So far, we have completed recording stripe rust data of our winter crop nurseries in various locations including Central Ferry, Mount Vernon, Wallla Walla, Lind, and Pullman (Palouse Conservation Field Station, Plant Path Farm, and Spillman Farm) in Washington and Hermiston, Ore. Wheat stripe rust developed to 90-100% severities on susceptible varieties in all locations except the ... Read More »
From Dr. Xianming Chen Since the last stripe rust update on May 7, stripe rust has been developing in the Pacific Northwest (PNW), especially in Washington. After the update, we received a report of stripe rust in commercial fields of winter wheat in Franklin County. On May 9, we checked the fields planted with Piranha CL+ and Nova AX, and stripe ... Read More »
By Dr. Xianming Chen On May 6, we were checking fields around Pullman, Wash. Winter wheat and barley ranged from Feekes 5 to 7. We were able to find stripe rust on susceptible checks in all our experimental fields at the Palouse Conservation Field Station, Plant Path Farm, and Spillman Farm. The incidence was low (<0.01%) in all locations, as ... Read More »
By Dr. Xianming Chen Research Plant Pathologist, USDA-ARS In the last two weeks, we were planting spring cereal nurseries and checking winter wheat fields in various locations. So far, we have found stripe rust in our disease monitoring and germplasm screening fields in various locations except those around Pullman. On April 9, our crew found stripe rust in our winter ... Read More »
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