Author
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SHARMA-POUDYAL, D. - Washington State University |
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Chen, Xianming |
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RUPP, R. - Washington State University |
Submitted to: International Journal of Biometeorology
Publication Type: Peer Reviewed Journal Publication Acceptance Date: 5/10/2013 Publication Date: 6/1/2013 Citation: Sharma-Poudyal, D., Chen, X., Rupp, R. 2013. Potential oversummering and overwintering regions for the wheat stripe rust pathogen in the contiguous United States. International Journal of Biometeorology. 58:987-997. Interpretive Summary: Stripe rust is one of the most important diseases of wheat. Epidemics are more frequent in the regions where the pathogen can oversummer and overwinter. Regions for potential oversummering and overwintering of the stripe rust fungus were determined in the contiguous United States using long-term means for temperature, relative humidity, rainfall, dew point, and snow depth. A survival index was developed. The pathogen can oversummer in the most regions north of latitude 40N, particularly Washington, Idaho, Montana, Oregon, and California. It cannot survive summer in Louisiana, Mississippi, Alabama, and Florida in the most regions south of 40N. Highlands of Arizona, Colorado, North Carolina, New Mexico, Nevada, Tennessee, Utah, Virginia, and West Virginia in the Rocky or Appalachian Mountains have climatic suitability for summer survival. Winter survival can occur in most regions south of 40N and the Pacific Coast. The pathogen cannot overwinter in the most regions north of 40N and east of the Rocky Mountains. Most wheat-growing regions in the United States are either suitable for oversummering or overwintering. Both oversummering and overwintering can occur in Arizona, California, Idaho, North Carolina, New Mexico, Oregon, Pennsylvania, Virginia, Washington, and West Virginia. These regions may provide primary inoculum for stripe rust epidemics in their own regions and surrounding regions. The information of the pathogen potential survival regions will be useful for control of stripe rust throughout the US. Technical Abstract: Epidemics of wheat stripe rust, caused by Puccinia striiformis f. sp. tritici (Pst), are more frequent in the regions where Pst can oversummer and overwinter. Regions for potential oversummering and overwintering of Pst were determined in the contiguous United States using a survival index (SI) ranging from 0 (most unfavorable) to 10 (most favorable) developed based on long-term weather data. The pathogen can survive in cool summer in the most regions north of latitude 40°N, particularly Washington, Idaho, Montana, Oregon and California. Due to limiting high temperatures, it survives marginally during summer in Arkansas, Delaware, Georgia, Iowa, Illinois, Indiana, Kansas, Kentucky, Massachusetts, Missouri, Ohio, Oklahoma, Rhode Island and Texas. Similarly, unfavorable hot summer restricts summer survival of the pathogen in the most regions south of 40°N except for highlands in the Rocky or Appalachian Mountains. Warm winters favor fungal survival in most regions south of 40°N and the Pacific Coast, including Alabama, Arkansas, Arizona, California, Florida, Georgia, Idaho, Louisiana, Mississippi, New Mexico, Nevada, Oregon, South Carolina, Texas and Washington. Severe winters do not allow survival in most regions north of 40°N and east of the Rocky Mountains, whereas less severe winter in Delaware, Illinois, Indiana, Kansas, Kentucky, Massachusetts, Maryland, Michigan, Missouri, North Carolina, New Jersey, New York, Ohio, Oklahoma, Pennsylvania, Rhode Island, Tennessee, Utah and Virginia permits marginal survival of Pst. Most wheat growing regions have climatic suitability for either oversummering or overwintering. Both oversummering and overwintering can occur in the Pacific Northwest (Idaho, Oregon and Washington), Arizona, California, North Carolina, New Mexico, Pennsylvania, Virginia and West Virginia. These regions may provide primary inoculum for stripe rust epidemics in their own and surrounding regions. |