|Milus, Eugene - U OF ARKANSAS|
|Jackson, Lee - U OF CALIFORNIA-DAVIS|
Submitted to: Cereal Rusts and Mildews Conference European and Mediterranean Proceedings
Publication Type: Abstract Only
Publication Acceptance Date: June 1, 2004
Publication Date: July 1, 2004
Citation: Chen, X., Milus, E.A., Long, D.L., Jackson, L.F. 2004. 2004. Impact of wheat stripe rust and races of puccinia striiformis f. sp. tritici in the united states. 11th International Cereal Rusts and Mildews Conference European and Mediterranean Proceedings. Page A2.11. Technical Abstract: Stripe (yellow) rust, caused by Puccinia striiformis f. sp. tritici, is one of the most important diseases of wheat in the US. Historically, it was most destructive in the western US (Washington, Oregon, Idaho, California) and sometimes caused damage in the south-central states (Texas, Louisiana, Arkansas). Since 2000, it has become increasingly important in the Great Plains (Oklahoma, Kansas, Colorado, Nebraska) and the south-central states. In 2000, the disease occurred in more than 20 states and estimated yield losses were 250,000 t ($27,000,000). In 2001, stripe rust was more widespread and caused severe damage in the Great Plains, and estimated losses were 1,100,000 t ($119,000,000). In 2002, stripe rust caused considerable damage in the western and south-central states, and yield losses were estimated at 220,000 t ($24,000,000). The national yield loss in 2003 was estimated at 2,420,000 t ($267,000,000), the highest in the last decade. In addition to the above losses, millions of dollars were spent on fungicide applications each year. The recent epidemics were attributed to the rust-favorable weather conditions and new races that overcame resistance in wheat cultivars. Among the 109 races identified from the early 1960's to 2003, 40 new races were identified in the last four years. Since first detected in 2000, a group of races that have common virulences on Lemhi, Lee, Fielder, Express, Yr8, Yr9, Clement, and Compair has become predominant. Races identified before 2001 were previously published (Chen et al., 2002; Line, 2002), and races identified since 2001 are presented in Table 1. High-temperature, adult-plant resistance, which is in major wheat cultivars in the Pacific Northwest (Washington, Oregon, and Idaho) and some cultivars in the Great Plains has prevented even greater losses.