Fusarium species and mycotoxins in maize in Switzerland

At several sites in Switzerland, the Fusarium incidence and the Fusarium species complex was assessed from maize kernels and stem pieces of commercially grown maize hybrids. The Fusarium incidence on kernels ranged from 0.4 % to 49.7 % and from 24.7 % to 83.8 % on stem pieces. Using the agar seed plate method, 16 different Fusarium species were isolated from kernels and 15 from stem pieces. Fusarium species prevalence differed between samples from the north and the south of the country, between kernel and stem pieces, between the different trial sites, as well as between the different years. The dominant species on kernels in the north were F. graminearum (33.0 %), F. verticillioides (28.9 %), F. subglutinans (10.6 %), F. proliferatum (7.0 %) and F. crookwellense (6.2 %). On stem pieces, the most frequently observed species were F. equiseti (36.0 %), F. verticillioides (20.1 %), F. graminearum (9.5 %), F. crookwellense (6.2 %) and F. sublutinans (6.2 %). In the south, the dominant species was F. verticillioides (57.1 %) und the fumonisin concentration in most of the samples exceeded the recommended maximum limits in feed of 5 mg kg-1.