|MURRAY, T. - Washington State University|
|ROBERTS, D. - Washington State University Extension Service|
Submitted to: Meeting Abstract
Publication Type: Abstract Only
Publication Acceptance Date: 3/30/2011
Publication Date: 6/13/2011
Citation: Murray, T.D., Chen, X., Roberts, D., Jin, Y. 2011. Role of barberry in stem rust epidemics and race diversity in Washington and Idaho, U.S.A., 2007-2009. Meeting Abstract. Page 166 in Oral Presentations.
Technical Abstract: Stem rust of wheat and barley is a chronic disease in eastern Washington and northern Idaho that typically doesn’t cause significant damage because it’s too dry and cool for optimal disease development. Nevertheless, epidemics occur in localized fields and cause significant damage in some years. Despite extensive eradication efforts in Washington from 1944-1981, barberry was not completely eradicated and has made a comeback in some areas. In 2007, two fields of spring barley with severe stem rust were identified in Stevens and Whitman Counties, WA with over 60% yield loss. Samples were collected from these two fields and analyzed at the USDA-ARS Cereal Disease Lab in St. Paul, MN. Fourteen races of Puccinia graminis f. sp. tritici were identified from these collections. Stem rust samples collected from wheat and barley in 2008 and 2009 from other areas of eastern WA and northern ID led to the identification of 11 and 22 races, respectively. Stem rust epidemics in this region are likely the result of inoculum from barberries and not urediniospores from other regions. Because of these outbreaks, we conducted surveys to locate barberries based on anecdotal reports and Barberry Eradication Program records. Barberry bushes were found in over 20 locations in Whitman and Stevens Counties, WA, and Latah County, ID. Consequently, the PNW Barberry working group was formed with state and federal personnel from Idaho, Montana, Oregon and Washington to investigate reports of stem rust and barberries and to educate the wheat and barley industry about this forgotten disease.