Climate variability and the daily agroecosystem forecasting accuracy plateau

Changing climate conditions have exacerbated the need for early warning systems that integrate with agroecosystem decision support. Short term forecasts are becoming more common, but it is not clear how current forecasting can practically be improved beyond the accuracy of current federal weather data forecast sources. One possibility is to systematically incorporate trends that are interannual or multidecadal in nature, as well as locally rare events, into current forecasting systems. We examine four types of long term variability that impact the eastern US, including the long term annual trend, El Nino Southern Oscillation, Atlantic Multidecadal Oscillation, and tropical cyclone frequency. Risks associated with two critical crop diseases, Fusarium head blight of small grains and late blight of potato, are assessed for the sixty year period 1950-2009 with respect to these aspects of climate variability. Each of these aspects of variability was significantly related regionally to daily crop disease risk forecasts. These results should be of interest to those implementing ecologically responsible integrated pest management strategies at various spatial and temporal scales as interannual patterns, multidecadal trends and rare events often confound the accuracy of short term forecasts.