Relating fusarium head blight in wheat to rainfall patterns using GIS and weather radar data in southern Ontario

摘要

Fusarium head blight and Gibberella ear rot are serious diseases affecting wheat and corn, respectively, in southern Ontario, with significant crop losses and mycotoxin contamination occurring in certain years. Rainfall is critical to epidemics for both diseases. Relating Fusarium outbreaks to canopy wetness is problematic due to the spatial and temporal variability of rainfall and an insufficient network of rain gauges. Site specific measurement of rainfall is required to analyse or predict epidemics. The weather radar network covers much of the agricultural areas of Ontario. A crop/rainfall monitoring programme is currently under development at the University of Guelph. Some results from a 1998 study of spore counts, disease (as measured by accumulated mycotoxin and visible symptoms), and rainfall events for winter wheat are presented here. Data were obtained from 30 sites over approximately 200km2 in southwestern Ontario while the wheat crop was heading. During this time, an isolated rain event passed through the middle of the area. This was measured using U.S.A. National Weather Service WSR-88D weather radar data that was assimilated into a GIS along with data on the subsequent spatial pattern of Fusarium occurrence. These occurrences were correlated to the rainfall patterns. Recent developments with Environment Canada weather radar is permitting this data to now be used for these studies, with a higher spatial resolution than the WSR-88D grid data. These results demonstrate the utility of integrated crop monitoring, climatic data acquisition, and GIS for crop management.