Spatial dynamics of T2+HT2 toxins in Swedish oats

The contents of T-2 and HT-2 toxins (T2+HT2) were analysed in 677 samples of oats delivered to silos in Sweden during the years 2020–2022. The spatial and temporal variation patterns in the prevalence of elevated T2+HT2 contents were explored and the covariation with temperature means or precipitation sums computed for windows of 15 days and T2+HT2 levels in the previous year were tested. There was a statistically significant spatial variation structure (Moran’s I; p< 0.05) in two of the years, and high T2+HT2 content was positively related to high content the previous year (p< 0.001). There were positive correlations between T2+HT2 content and warm weather in July and negative correlations with precipitation in May and July in two of the years. This is the first time a pronounced regional variability for T2+HT2 is presented. The results can be valuable when searching for safe regions to produce grains intended for food for infants. In a sampling campaign in 11 fields, it was found that T2+HT2-levels can vary substantially within fields.