Climate, weather, and the heterogeneity of Fusarium head blight
A. B. KRISS (1), L. V. Madden (1), P. A. Paul (1), X. Xu (2)
(1) The Ohio State University, OARDC, Wooster, OH, U.S.A.; (2) East Malling Research, West Malling, UNITED KINGDOM
Phytopathology 101:S221

Fusarium head blight (FHB) is a serious yield-limiting and toxin-producing disease of wheat, which is highly variable in time and space. Empirical quantification of the variation in FHB in relation to climate and weather variation will aid in the advancement of disease forecasting. Three analytical approaches were used to address this heterogeneity. First, window-pane analysis was used to investigate the FHB-weather-climate relationship across multiple years and regions in the U.S. and Europe. Moisture- or wetness-related variables (e.g., daily relative humidity) were found to be positively correlated with FHB intensity in the U.S., and with disease and/or toxin levels in Europe for multiple window lengths and starting times. Second, cross-spectral analysis was used to show coherency between inter-annual variation in FHB from two locations in the U.S. and global climatic patterns, such as the El Niño-Southern Oscillation. There were significant coherencies at one or more inter-annual time scales (i.e., periods), with the climatic indices for winter or spring leading the FHB series by 2 to 9 years. Third, results from a novel spatial analysis of survey data using generalized linear mixed models confirmed that FHB incidence is also heterogeneous on multiple spatial scales, with variation larger at the county or field scale relative to the within-field (sampling-unit) scale. This likely resulted, in part, from environmental variation among counties and fields.

© 2011 by The American Phytopathological Society. All rights reserved.