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ARS Home » Pacific West Area » Pullman, Washington » WHGQ » Research » Publications at this Location » Publication #297369
Title: Stripe rust epidemiological regions, virulence dynamics, pathogen reproduction modes, yield losses, forecasting models, and management in the United States

Author
item Chen, Xianming
item SHORMA-POUDYAL, DIPAK - Washington State University
item WAN, ANMIN - Washington State University
item WANG, MEINAN - Washington State University
item CHENG, PENG - Washington State University
item Evans, Conrad
item ARIZA, LOREN - Washington State University

Submitted to: Meeting Abstract
Publication Type: Abstract Only
Publication Acceptance Date: 7/1/2013
Publication Date: 8/21/2013
Citation: Chen, X., Shorma-Poudyal, D., Wan, A., Wang, M., Cheng, P., Evans, C.K., Ariza, L. 2013. Stripe rust epidemiological regions, virulence dynamics, pathogen reproduction modes, yield losses, forecasting models, and management in the United States. Meeting Abstract. 11th International Epidemiology Workshop. Page 32.

Interpretive Summary: Stripe rust of wheat is one of the most important diseases in the US. Areas where the fungus is able to survive summer and/or winter were determined using historical weather data based on the biological requirements of the pathogen. Monitoring the disease is conducted through collaboration throughout the country. A new set of wheat lines each with a single resistance gene has been recently established and used to differentiate pathogen races. The reproduction modes of the pathogen were determined by virulence and molecular characterization of natural populations, somatic hybridization of isolates under artificial conditions, rust surveys on alternate hosts of Berberis and Mahonia species, and survival ability of teliospores. Potential yield loss and fungicide response for major winter and spring wheat cultivars are determined every year, and the data are used for guiding stripe rust management on an individual-cultivar basis. A set of prediction models has been developed and used to forecast potential yield losses. Recommendations for stripe rust control are made based on disease forecast and monitoring data, weather conditions, pathogen races, and types and levels of resistance of individual cultivars. Rust updates and recommendations are delivered directly to growers through e-mails, websites, and telephones. The effective management of stripe rust has prevented major damage and saved growers multimillion dollars every year.

Technical Abstract: Stripe rust of wheat, caused by Puccinia striiformis f. sp. tritici (Pst), is one of the most important diseases in the United States. Epidemiological regions were determined based on epidemic patterns, cropping systems, geographic barriers, weather patterns, and inoculum exchanges. Areas where Pst is able to survive summer and/or winter were determined using historical weather data based on the biological requirements of the pathogen. Monitoring the disease is conducted through collaboration during the crop growth season throughout the country. A new set of wheat lines each possessing a single resistance gene was recently established and has been used to differentiate Pst races. The changes in frequency and distribution of individual virulence genes and races were determined based on the data over the years. The reproduction modes of Pst were determined by virulence and molecular characterization of natural populations, somatic hybridization of Pst isolates under artificial conditions, rust surveys on alternate hosts of Berberis and Mahonia species, and survival ability of teliospores. Annual yield loss for each state is estimated by collaborators based on disease severity and fungicide application. In the Pacific Northwest, potential yield loss and fungicide response for major wheat cultivars and susceptible checks are determined every year using completely randomized split-block design experiments for both winter and spring crops. The data are used for guiding stripe rust management on an individual-cultivar basis. Weather factors affecting stripe rust were identified through correlation analysis with historical weather and disease data. A set of prediction models was developed and has been used in each year to forecast potential yield losses for susceptible cultivars using December temperatures and combinations of various weather factors throughout the entire winter season. Recommendations for effective management of stripe rust, including mainly growing resistant cultivars and appropriate fungicide application, are made based on disease forecast and monitoring data, weather conditions forecasted for the near future, Pst races, and types and levels of resistance of individual cultivars. Rust updates and recommendations are delivered directly to growers through e-mails, websites, and telephones. The effective management of stripe rust has prevented major damage and saved growers multimillion dollars every year.