Abstract

In Norway, Fusarium diseases and associated mycotoxin contamination in spring oats occasionally cause problems for growers, livestock producers and the food and feed industries. Besides weather factors, such as rainfall and temperature in the critical periods around flowering and before harvest, inoculum production and disease development are influenced by agricultural practices. The occurrence of Fusarium graminearum and DON in oat grain lots do not generally correlate with that of Fusarium langsethiae and HT-2/T-2-toxins. Therefore, to develop a robust disease management strategy, there is a need to reveal the influence of weather and agricultural practice on disease development in oats for both these fungal species. Through various research projects NIBIO researchers have performed field trials to study the effects of straw management, tillage practice, cultivar, and chemical and biological control treatments on the development of Fusarium spp. and mycotoxins in oats. In particular we have investigated whether the amount of straw residues and tillage practice influences the survival of Fusarium spp. in residues, and the subsequent Fusarium spp. infection of the harvested grains. In addition, Fusarium spp. DNA and mycotoxin content (DON and HT-2/T-2) have been analysed in oats from current official cultivar trials. This work has been a collaboration between NIBIO and the Norwegian Agricultural Extension Service. Results will be presented on the Fusarium spp. and mycotoxin contamination of grains harvested from oats grown under various agricultural practices. High incidence of Fusarium avenaceum are often observed in harvested grains as well as straw residues. Fusarium graminearum is also commonly detected. Despite the high concentrations of F. langsethiae DNA and HT-2/T-2 toxins sometimes recorded in oat grain, only low levels of F. langsethiae have been detected in crop residues and air samples. We speculate that the life cycle of F. langsethiae differs from those of F. graminearum and F. avenaceum with regards to survival, inoculum production and dispersal.