Fusarium graminearum was first identified in Manitoba in 1923, but no serious outbreaks were reported until 1984. Since then, surveys in western Canada conducted by the Grain Research Laboratory have found F.graminearum in an ever-expanding area, now reaching into northern B.C. F. graminearum is only one of many species of Fusarium , but it is considered the most important one in Canada because of the impact it has on yield and grain quality, its ability to produce several different toxins, and its abundance in eastern Canada and the eastern prairies. In eastern Canada, it appears to be well established in all the cereal growing areas. In western Canada, F. graminearum is found most frequently in the black soil zone. This zone is also the area of highest rainfall on the prairies.
Infection is associated with rainfall during the flowering stage.
The infection is spread by wind, but the pathogen may also be spread by planting infected seed. The maps illustrate the relationship among F. graminearum, F. avenaceum and F. culmorum, the black soil zone, rainfall and temperature on the prairies. Fusarium head blight is most successful when rainfall occurs during the flowering stage, usually in July. This map shows the 30 year average precipitation for July in the crop districts of western Canada. Many areas of western Canada have precipitation levels in July equivalent to those of southern Manitoba, indicating that moisture levels at flowering will likely promote further westward spread of F. graminearum .