Detecting Patterns of Wheat Stripe Rust Pandemics in Time and Space

Pandemics of wheat stripe rust from 1950 to 1990 were analyzed with data from five key regions in different geographical areas in northern China. Epidemics in one region were correlated with epidemics in other regions. Spatial correlation coefficients increased as spatial distance decreased. The epidemic time series of the source region, where rust occurs year round, was not correlated with lagged epidemic series of regions in the dispersion area. Average epidemic indices of one region were associated with distance from the source region and latitude of the region. Time series analysis also was used to determine temporal pattern (...)