By the OMAFRA Field Crop Team
Harvesting is of course the preferred option but for some producers finding a market for mouldy or corn with high levels of DON content can be difficult this year as well as it takes time to find alternative uses or streams for this corn. Livestock producers, especially those with hogs, cannot feed high DON corn to their animals without considerable blending or additives.
If corn contains low to moderate DON levels, grain cleaning with rotary screen type or gravity-based cleaners for example has been shown to be effective in reducing mycotoxin levels in the remaining grain. The resulting high-DON screenings will be lower volume and easier to deal with than the entire grain mass.
Storing grain until harvest is complete will allow the market to get a better picture of the entire 2018 harvest. Once pressure from harvest eases, it may be easier to assess marketing opportunities for lower-quality grain.
Corn infected with DON can potentially be used as a feedstock for anaerobic biodigesters. However, only a limited number of digesters capable of handling grain corn exist in the province. Grain corn will likely require grinding prior to feeding a digester, as whole kernels will simply sink to the bottom of the digester.
Ethanol plants would seem to be a logical delivery point. However, the ethanol distillation process concentrates DON in the dried distillers grains (DDGs) 3 times higher than the original grain. DDGs are sold for livestock feed, and account for significant revenue for ethanol plants. High DON levels may render the DDGs unsaleable.
Composting grain is impractical and requires significant water addition and active management.
Landfilling contaminated grain is costly and impractical. Costs in excess of $100 / tonne can be expected from municipal landfills.
Burning compromised grain to produce heat is a possible alternative. Corn as a heating fuel is 3 times less expensive than propane or heating oil. However, specialized furnaces or boilers are needed and therefore this is unlikely to be feasible unless the heating system already exists.
Crop destruct of either the grain or standing crop is an option although an unpleasant option. Grain retains a significant fertilizer value, and could be ground up and land-applied as a last resort. Grinding before land applying accelerates breakdown and prevents germination of volunteer plants. This may be the most practical method for handling large volumes of unmarketable grain. Mowing and incorporation of the corn residues have been used in US Midwest states when they have had similar ear rot and mycotoxin issues.
For more ear mould and mycotoxin information as well as other field crop disease management issues , visit the Crop Protection Network Website.