Corn Contaminated With Smut Can Still Create Quality Silage

With wet conditions across much of the U.S., producers should be on the lookout for corn smut. The good news is that affected crops can still be used for silage with a careful inoculant choice and close monitoring. 

 

"While producers may see a drop in corn yields due to smut contamination, the crop is still valuable and can be successfully ensiled," says Renato Schmidt, Ph.D., Forage Products Specialist, Lallemand Animal Nutrition. "The fungus that causes smut does not itself produce toxins, and studies in sheep have shown it does not affect feed intake." 

 

Corn smut is caused by the growth of Ustilago maydis, which thrives in conditions of high humidity, poor pollination or damage from insects or equipment. Once the plant is infected, the fungi's cells divide quickly and expand. This leads to large gray galls that contain black spores, typically on the corn ear tip. 

 

The resulting galls decrease grain yield anywhere from 9 to 40 percent. When fed, Ustilago maydis can affect feed efficiency. Feed digestibility also can be reduced when infestation levels reach 50 percent or greater.3 Research shows total digestible nutrients (TDN), net energy for maintenance (NEM) and net energy for gain (NEG) values of corn silage decreased around 0.5 percent, 0.02 mcal/g, and 0.02 mcal/g, respectively, for each 10 percent rise in smut-infested plants. 

 

When corn contaminated with smut is ensiled, the disease also can restrict the rate and extent of fermentation and predispose the plant to further mold growth and the production of mycotoxins, Dr. Schmidt warns. 

 

"Corn contaminated with smut can still be used for silage, but we strongly recommend using an inoculant that is research-proven to help drive a fast, efficient initial ensiling fermentation and inhibit the growth of detrimental spoilage microbes during feeding," Dr. Schmidt advises. "This can help keep the silage stable."

Video: Independent Seed, National Impact | On The Brink: Episode 9

A survey of 200 independent seed businesses reveals what Canada's seed sector actually contributes — and what it stands to lose.

On the Brink, Justin Funk, a third-generation agri-marketer, shares the findings of a national survey conducted in early 2026. The numbers reframe the conversation: independent seed companies in Canada represent upwards of $1.7 billion in dedicated seed infrastructure, approximately 3,000 full-time equivalent jobs in rural communities, and an estimated $20 million in annual community contributions. And roughly 90% of Canada's cereals, pulses, and other small pollinated crops flow through them.

The survey also asked how dependent these businesses are on public plant breeding to survive. The answer was unambiguous. For policymakers evaluating the future of publicly funded breeding programs, Funk argues the economic case for this sector and the case for public plant breeding are the same argument.

On the Brink is a cross-country video series exploring the future of plant breeding in Canada. Each episode features voices from across the industry in an open, ongoing conversation about innovation and long-term investment in Canadian agriculture.