On-farm experiments over 5 years in a grain maize/winter wheat rotation: effect of maize residue treatments on Fusarium graminearum infection and deoxynivalenol contamination in wheat

Abstract

Over the course of 5 years, different maize residue treatments were conducted on 14 zero tillage on-farm sites in Switzerland to evaluate their effect on the development of Fusarium head blight (FHB) and the contamination with the mycotoxin deoxynivalenol (DON) in winter wheat grains and wheat straw following grain maize. Two experimental series with three and five different treatments were carried out, respectively. Fusarium graminearum (Schwabe) was the predominant FHB-causing species with an overall incidence of 15% infected wheat grains. A significant correlation between symptoms in the field, F. graminearum incidence and DON content in wheat grains and wheat straw was observed. The average DON content in both wheat grains and wheat straw was approximately 5,000 μg/kg and thus several times higher than the European maximum limit of 1,250 μg/kg for unprocessed small-grain cereals for human consumption. Of all grain samples, 74% were above the maximum limit. Pooled over both experimental series, the average reduction of DON in grains through treatments of the maize residue compared with a control treatment ranged between 21 and 38%. The effect of various other factors, including the year, the wheat variety, the site, the maize hybrid and the production system was evaluated as well. The year and the wheat variety were the most important FHB influencing factors. Over all treatments, the variety Levis showed a fivefold higher average DON content compared with the variety Titlis. From different categories of maize residue particles, intact pieces of 5-15 cm length were strongly correlated with F. graminearum incidence and DON content in grains. During the time course of this study, the recommendation from a preliminary version of the internet-based DON forecasting system FusaProg to apply or to omit a fungicide treatment was correct in 32 out of 42 cases. The results are currently being used to optimise the FusaProg models. This study has shown that in a grain maize/winter wheat rotation, the DON content in wheat grains frequently exceeded the European maximum limit, even with a thorough treatment of maize residues and less susceptible wheat varieties. Hence, in order to reduce the contamination risk in a zero tillage system, the crop rotation needs to be modified.

Airborne and Grain Dust Fungal Community Compositions Are Shaped Regionally by Plant Genotypes and Farming Practices

“…Thus, the selection of wheat cultivars for their resistance to different wheat diseases affects the infection of wheat not only by the fungal phytopathogens but also by the other members of the fungal community. In addition, our results provide evidence that cropping history might influence both the diversity of fungal phytopathogens (51,52) and the overall diversity of the fungal community. These findings are similar to those previously published by Nicolaisen et al (9).…”

The variability of the occurrence of Fusarium culmorum in winter wheat grain in relation to climatic conditions and cultivation methods

“…in crops (Moszczyńska, Pląskowska, 2005). However, sowing wheat after a preceding crop of corn may induce considerable infection of grain by mycotoxins (DON, NIV and ZEA) of Fusarium fungi (Vogelgsang et al, 2011).…”

Infection conditions of Fusarium graminearum in barley are variety specific and different from those in wheat

“…In Switzerland, F. graminearum (FG) is the most occurring species in barley and wheat (Schöneberg et al 2016;Vogelgsang et al 2011) and the typical symptoms are discoloured and shrivelled grains (Parry et al 1995). Apart from reduced grain quality and yield, FG produces mycotoxins such as deoxynivalenol (DON) (Bottalico and Perrone 2002;Osborne and Stein 2007).…”