Performance Story: Post Harvest DON reduction Strategies for Canadian Western Spring Wheat, Durum and Barley
Dr. Rex Newkirk, University of Saskatchewan
Deoxynivalenol (DON) is the major secondary metabolite produced by Fusarium graminearum. F. graminearum can infect cereals such as: wheat, durum, barley, rye and corn. This toxin can make the grain unmarketable for producers. This study examined methods to recover high quality (low DON) wheat and barley from infected seed lots.
Seed sorting by BoMill (Near Infrared Transmittance single seed sorting), air fractionating grain cleaning, the combination of the two and oxidation of the mycotoxin through introduction of Ozone gas produced by an ozone generator into the air stream of an aeration bin during grain drying immediately following harvest. The BoMill technology effectively sorted both wheat and barley into high and low DON fractions resulting in recovery of significant quantities of low DON wheat especially when using the Fusarium calibration combined with the appropriate vitreous kernel setting and precleaning. Air fractionation effectively separated infected wheat and barley based on relative grain density but the air speed settings had a significant impact. The combination of air fractionation followed by sorting of mid DON fractions on the BoMill was the most effective method of recovering high quality wheat and barley from material that otherwise had few marketing opportunities. Abrasion of grain followed by air fractionation failed to reduce DON levels. Ozone treatment during drying by aeration significantly reduced DON concentration (up to a 50% reduction) and would be effective when grain is only marginally too high to market but in more extreme cases the combination of air fractionation and BoMill sorting are recommended.
Key findings include:
DON levels can be reduced in fusarium infected wheat and barley by adding ozone gas to the air inlet during grain drying and aeration.
Fusarium infected wheat and barley containing high levels of DON can be effectively detoxified and sorted into low DON factions using simple air fractionating grain cleaner or a BoMill NIRS grain sorter
A combination of grain cleaning followed by BoMIll sorting was the most effective method of recovering low DON grain.
Abrasion of grain followed by air classification did no reduce DON levels, however, grinding with a hammer mill prior to incorporation into the diet did.