Mycotoxin-producing Fusarium Species Occurring in Winter Wheat in Belgium (Flanders) During 2002-2005

Deoxynivalenol (DON) content and Fusarium spp. (Fusarium graminearum, Fusarium culmorum, Fusarium avenaceum, Microdochium nivale and Fusarium poae) of mycotoxin-producing Fusarium species in winter wheat in Belgium (Flanders) were determined. Field trials were set up in the varietal testing network of Flanders Agricultural Centre for Small Grains (Roeselare - Beitem, Belgium) and followed up during growing seasons 2001-2002, 2002-2003, 2003-2004 and 2004-2005. Fusarium infection and DON contamination were mainly influenced by location and environmental parameters. Mean DON levels ranged from 0 to 15 mg/kg. Over the period of four growing seasons cvs Deben, Ordeal and Napier had the highest DON contamination. Seasonal and local weather conditions before and during flowering together with local crop husbandry measures (crop rotation, soil preparation) seemed to be of great importance in explaining the variation in results obtained. At Bottelare a positive correlation between disease index and DON content was found for the growing seasons 2001-2002 and 2002-2003, but not the season 2003-2004. Fusarium graminearum and F. culmorum were in general the most frequently occurring Fusarium spp. in Flanders over the 4 years but the composition of the Fusarium population varied strongly from location to location and from year to year. Fusarium graminearum predominated in areas especially where maize was cultivated, whereas in areas with more small cereals in the crop rotation more F. culmorum was present. Also temperature played a role in the composition of Fusarium spp.