Mycotoxins and toxigenic fungi on cereal grains in western Canada.

Toxins occasionally present on cereal grains in the field in western Canada include ergot alkaloids produced by Claviceps purpurea and trichothecenes produced by Fusarium species, particularly Fusarium sporotrichiodes and Fusarium graminearum. HT-2 toxin, T-2 toxin, diacetoxyscirpenol, and deoxynivalenol are the main trichothecenes encountered. During storage of cereals, the predominant toxins and toxigenic fungi are ochratoxin A and citrinin produced by Penicillium aurantiogriseum, P. chrysogenum, and P. verrucosum and sterigmatocystin produced by Aspergillus versicolor. The incidence of toxin-contaminated grains is extremely low relative to the volume of grains produced. Occurrence of toxins is influenced by field moisture, temperature, and bin storage conditions of a particular year. The risk of toxin production is highest in durum wheat and lowest in oats.