Fusarium species and mycotoxins in silage maize – results of a five-year monitoring programme

within the context of a five-year silage maize monitoring programme (2010–2014) in the cantons of Aargau and Bern, Agroscope investigated Fusarium infection and mycotoxin contamination of silage maize, as well as the influence of cropping factors including variety, previous crop, tillage, and sowing and harvest dates. Out of 169 harvest samples, 167 showed a mean Fusarium fungus incidence of 57%. A wide variety of Fusarium species was observed; in addition, a number of samples contained mycotoxin levels exceeding the guidance values for feed. Samples from silage maize fields with reduced tillage showed a significantly higher contamination with deoxynivalenol (DON) than samples from ploughed fields. Samples from fields with a later harvest date were more heavily infected with F. graminearum, and higher DON and zearalenone levels were observed. In contrast, previous crop and corn borer infestation did not have a significant influence on Fusarium infection and mycotoxin concentration, whereas the prevailing weather conditions had the strongest effect on Fusarium infection. This study clearly demonstrated that the sowing of early silage maize varieties and early harvesting significantly reduces the risk of Fusarium infection and mycotoxin contamination.