What to do with mouldy corn

There are several ways to sell – or dispose of – corn with high DON levels

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With comparatively high mycotoxin issues this year’s corn crop, Ontario farmers are increasingly wondering what to do with infected grain.

But while circumstances may not be ideal, options do exist – some perhaps more appealing than others.

Why it matters: Finding a market for mycotoxin-infected corn is not easy, but there are options. However, many factors can influence whether those options are practical.

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Closeup of fully ripe corn cobs ready to be harvested. Leaves are dry and bent outwards. There are many corn plants in background, blurry.
Ripe corn plants with a dusting of snow

The usage of the high DON level corn is a topic of increasing worry for farmers. A summit will be taking place the week of Nov. 12 to try to find industry-wide solutions for managing the corn. In the meantime, here are some options for managing high mycotoxin corn. Ernie Hardeman, Ontario’s ministry of agriculture food and rural affairs, recently visited a farm along with Grain Farmers of Ontario officials to discuss the issue.

Delivering to elevators still an option

Mycotoxin infected corn can be brought to the elevator, though financial penalties and the risk of outright rejection increase in conjunction with toxicity (measured in parts per million). The threshold for rejection is also not fixed, making it more difficult – and frustrating – for farmers to know if a load will be accepted. Some are finding loads not accepted at one elevator will be accepted at another – with a lower measurement.

Indeed, the same load of grain might be rejected one day then accepted the next.

“The end user has introduced testing and discounts that we have to follow,” says Vicki Michinski, grain originator for Great Lakes Grain – a division of Southwestern Ontario’s Agris Co-operative Ltd. “Standards do change. Rates change in accordance to area and where the corn is going.”

Michinski says larger loads are more likely to be accepted since mycotoxins can be more easily diluted with the overall load. She adds her company tries to work with each individual farmer as issues arise. An important part of that is ensuring load samples provide genuinely fair representations of the load as a whole.

“We’re in the middle here. If we ship a load to [our end buyers] and it’s at five parts per million, they reject it from us,” she says. “It’s a challenging year, but as a co-op we’re working through it.”

Cleaning and storing to improve marketability

Ontario Ministry of Agriculture, Food and Rural Affairs (OMAFRA) maintains a number of resources covering mycotoxin issues in grain. These resources say producers can effectively clean mycotoxin from corn using rotary or gravity-type cleaning systems – so long as the infection rate is between low and moderate – to help improve marketability.

Ministry resources also say storing contaminated corn until a more complete picture of the 2018 harvest develops is an option. Storing mycotoxin-laden corn is not a simple process, however, and extra steps should be taken to avoid aggravating the problem (see “Storage tips for mouldy corn” for more). Mouldy corn should also be stored separately from clean grain.

Albert Tenuta, field crop pathologist with OMAFRA, says diluting contaminated corn with clean corn to achieve better overall quality is a useful practice at elevators and for others working with larger quantities of grain. At the individual farm level, though, it’s much more difficult to do.

“You don’t want to make good corn into bad corn,” he says. “It really depends on what [moisture] levels are. If it’s six, seven, eight per cent or more you need a lot of good corn to dilute it, You’re still at the mercy of sampling and may not get the expected outcome.”

If someone were to dilute their crop anyway, Tenuta says it’s good practice to ensure at least some clean corn is separately saved. It might come in handy if further quality modifications are required.

Ethanol possibilities

“We’re looking at approximately three times the levels [of mycotoxin] in dried distillers’ grain. At that point CFIA regulations kick in,” says Andrea Kent, vice president of communications and public affairs for Greenfield Global – a large ethanol manufacturer maintaining three distillation plants in Ontario.

Kent says her company recognizes the difficulty being experienced by all players in the supply chain this year. Any corn shipments that are rejected, she says, are very well tested.

Other options

OMAFRA lists several other ways to unload and use mycotoxin-infected grain.

Digestor feedstock
Corn infected with mycotoxins can potentially be used in anaerobic digestion, but only a limited number of digesters capable of handling grain corn currently exist within Ontario. In addition, grain used in this way needs to be ground prior to entering the digester (whole kernels sink to the bottom and will not break down properly).

Mouldy corn can still be used for ethanol. However, the distillation process concentrates mycotoxins in the leftover dried distillers’ grain, which can make it unfit for use as animal feed. This is a problem because the sale of distillers’ grain to livestock farmers constitutes a significant portion of revenue for ethanol producers. Consequently, opportunities to sell corn to ethanol are limited.

Furnace and boiler fuel
Corn can be harvested and sold as a fuel for heating. While cheaper than oil and propane, though, purchasers would already need specialized corn furnaces or boilers to make the arrangement feasible.

“Last resort” crop residue
Although an otherwise “unpleasant option,” corn can be reincorporated into the soil by grinding and applying as a fertilizer. This, says the ministry, might be “the most practical method for handling large volumes of unmarketable grain.” Mowing and incorporating corn residues in field that have not yet been harvested is also an option.

Composting grain or dumping it at the landfill, OMAFRA says, are impractical and can be very expensive. Consequently, they are not advisable courses of action.

In light of the current reality, Grain Farmers of Ontario issued a statement to members encouraging them to directly contact Agricorp to start the crop insurance assessment process – even if they do not have immediate issues. This, says the organization, is because the assessment process will take some time. Here’s the link to the latest information from Agricorp.

The next few weeks

According to Tenuta, only 25 to 30 per cent of Ontario’s corn crop has been harvested as of  early November, thanks in part to a combination of wet weather and time spent driving grain from elevator to elevator.

However, the situation in some areas of the province – the southwest specifically – is not uniformly dire.

“Once this weather turns and people can get back out there, it might not be a bad idea to go after the good quality corn right away,” says Tenuta. “It would help fill contracts and gives you time to plan for what to do in other fields as well.”

About the author


Matt McIntosh

Matt is a freelance writer based between Essex County and Chatham-Kent. He is interested in all things scientific, as well as rock n' roll, hunting and history. He also works with his parents on their sixth-generation family farm.



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