Fusarium species and DON contamination associated with head blight in winter wheat over a 7-year period (2003-2009) in Belgium

The occurrence of Fusarium species in winter wheat in southern Belgium (Wallonia) and the deoxynivalenol content in 692 samples collected in commercial fields in the region's main cereal growing area were investigated. The main Fusarium species associated with head blight in wheat were identified at levels that varied from year to year. Interactions between fungal species causing head blight in wheat were detected, most of them positive. The years 2007 and 2008 were very conducive to the disease and there was a strong correlation between mean annual deoxynivalenol content and number of days with a mean relative humidity above 80% over a period starting from 7 days before the mean flowering date and ending 16 days after this date. A two-stage approach, based on type of year (at risk or not) and agricultural practices during risk years has been developed to help cereal storage companies reduce the risk of mixing sound and deoxynivalenol-contaminated lots at harvest and to limit the number of analyses.