Deoxynivalenol and nivalenol in commercial wheat grain related to Fusarium head blight epidemics in southern Brazil

► Deoxynivalenol and nivalenol were found in Brazilian commercial wheat grain. ► Co-occurrence of these toxins in the same grain sample was predominant. ► Levels of toxins were comparable and most samples were below 750 μg/kg. ► A positive relationship was found between kernel damage and toxin levels. ► Widespread occurrence of nivalenol has agronomic and toxicological implications.