Strategies to reduce DON contamination of wheat with different soil tillage and variety systems

Abstract

With the focus on minimizingFusarium head blight and the deoxynivalenol (DON) contamination of wheat a three year crop rotation system starting with forage maize and followed by two years of winter wheat was combined with three soil tillage systems and selected plant varieties with varying susceptibility toFusarium infection.Higher DON concentrations were generally observed in wheat grain when the soil was mulched rather than ploughed, depending on the mass of maize residues remaining on the soil surface. Maize residues are the most important source ofFusarium inoculum. Infected maize residues had a main impact on the level of DON contamination in wheat grain particularly in the first year after maize cultivation. When the maize stubble was chopped before mulching, the decomposition of the residues was speeded up and the DON contamination of the wheat grain was lower. In the second year following the maize crop, the decomposition of the maize residues/Fusarium biomass was nearly complete and the infection risk was reduced considerably. An influence of the susceptibility of the maize variety against stem rot on the DON concentration of the succeeding winter wheat crop was not observed. The less susceptible wheat variety was suitable for controlling the higher infection risk deriving from the introduction of maize in wheat rotation and the use of mulching techniques.

Uptake of deoxynivalenol by earthworms from Fusarium-infected wheat straw

“…The major toxin produced by F. culmorum is the trichothecene mycotoxin deoxynivalenol (DON) (Wagacha and Muthomi 2007). Higher DON concentrations have been recorded in wheat grain when the soil was mulched compared with ploughing due to higher mass of infectious plant residues remaining on the soil surface (Oldenburg et al 2007). …”

Fungal contamination and <i>Fusarium</i> mycotoxins in cereals grown in different tillage systems

“…Similarly, limited tillage systems increase the number of Fusarium spores in the soil (Parry et al, 1995;Oldenburg et al, 2007).…”

“…Narrow cereal rotation systems, in combination with conservation tillage, are potentially more likely to promote Fusarium infection than wide cereal rotations including legumes or catch crops, and/or ploughing. It is therefore recommended to optimize tillage systems to control Fusarium infection in cereal production (Oldenburg et al, 2007).…”

Within-field variation of mycotoxin contamination of winter wheat is related to indicators of soil moisture

“…Agricultural practices play an important role in the infection, colonization and development of fungi and their production of DON and ZEA in the infected kernels (Champeil et al 2004a). Tillage practices (conservation or notillage), short intervals between susceptible host plants (crop rotations that include high proportions of cereals and maize) and low resistance level among the wheat cultivars have been described to be important driving factors that can considerably enhance the mycotoxin accumulation in mature wheat grain (Yi et al 2002;Champeil et al 2004b;Parylak 2004;Brennan et al 2007;Oldenburg et al 2007).…”