Submitted to: Wheat Newsletter
Publication Type: Research Notes
Publication Acceptance Date: March 1, 2005
Publication Date: July 25, 2005
Citation: Chen, X., Wood, D.A., Penman, L., Ling, P. 2005. Epidemiology and control of wheat stripe rust in the united states, 2004. Annual Wheat Newsletter, 51: 240-242. Interpretive Summary: This report in the Annual Wheat Newsletter summarizes our research results in 2004. Summery covers research findings in the following aspects: 1). Monitoring rusts, predicting epidemics, assessing yield losses, and identifying races of Puccinia striiformis f. sp tritici; 2). Test wheat germplasms and breeding lines for rust resistance; 3). Determine genetics of resistance, develop molecular markers and clone genes for resistance to stripe rust; and 4). Determine effectiveness and use of foliar fungicides for rust control.
Technical Abstract: Wheat stripe rust (Puccinia striiformis f. sp. tritici), leaf rust (P. triticina), and stem rust (P. graminis f. sp. tritici) were monitored throughout the Pacific Northwest (PNW) using trap plots and field survey in 2004. The diseases were accurately predicted for the PNW using monitoring data and predictive models based on resistance of wheat cultivars and environmental factors such as temperature and precipitation. Through cooperators in many other states, wheat stripe rust was monitored throughout the United States. In 2004, wheat stripe rust occurred in 17 or more states including Alabama, Arkansas, California, Colorado, Indiana, Kansas, Louisiana, Minnesota, Missouri, Nebraska, Ohio, Oklahoma, Oregon, South Dakota, Texas, Washington, and Wisconsin. Wheat stripe rust was much lighter and its damage was much less in the Great Plains in 2004 than in 2003. However, the disease continued destructive in Pacific West (California, Oregon, Washington, and Idaho). Stripe rust alerts were sent to growers through e-mails and news releases to implement control with fungicide applications. As a result, most of fields grown with susceptible or moderately susceptible cultivars were appropriately sprayed with fungicides in the Pacific Northwest. The on-time application of fungicides prevented major losses. The wheat yield losses by stripe rust in Washington State were estimated as 1.5% for winter wheat and 3% for spring wheat. A total of 11,756,000 bushels of wheat yield losses caused by stripe rust in the United States was estimated in 2004 (http://www.cdl.umn.edu). In the Pacific Northwest, leaf rust occurred in some areas but the severity levels were low except in northwestern Washington. Stem rust was not observed.