Prevalence of fungi and fusariotoxins on oat seed from western Canada, 1995-1997

The mycoflora and levels of deoxynivalenol (DON) on oat seed (Avena sativa) grown in western Canada was determined by analyzing a total of 511 grain samples collected from 39 crop districts in Alberta, Saskatchewan, and Manitoba during 1995-1997. Fungi representing a minimum of 85 species were recovered. Alternaria alternata was the most frequently isolated species from each province. Levels of A. alternata, Bipolaris sorokiniana, and Fusarium graminearum were highest in Manitoba and eastern Saskatchewan. whereas Cladosporium species and Drechslera avenacea were highest in samples from Alberta and western Saskatchewan. DON levels greater than or equal to 0.10 ppm were found in seeds from two Manitoba crop districts in 1996 and three in 1997, with a maximum level of 0.34 ppm. In 1997, DON was also detected in composite samples of seed from three Saskatchewan and two Alberta crop district composites.