Buyer refuses oats desiccated with glyphosate due to quality loss

One of the largest oat buyers in Western Canada will no longer purchase oats if the crop has been desiccated with glyphosate.

Grain Millers Inc., a Minnesota based firm and supplier of ingredients to global food manufacturers, announced its new policy last week in a memo to prairie oat growers.

Terry Tyson, Grain Millers procurement manager in Yorkton, Sask., said the company has been considering the policy for a while.

About three years ago they started to notice problems with oat quality and functionality, which resembled frost damage, but weren’t sure about the cause.

“When mills cut, flake or roll the groat, it is chalky, it’s brittle, it breaks apart and the finished product doesn’t make spec, in terms of granulation or absorption,” Tyson said. “The groat integrity is affected much like an early frost affects groat integrity…. (But) frost damage you can see on the groat. You can control it… by rejecting a truckload or carload…. The damage with this issue is somewhat subtler.”

Tyson said desiccating oats with glyphosate, the active ingredient in Roundup herbicide, has increased in the last five years in Western Canada. He said the practice might have reached a critical mass, where detrimental effects on oat quality have become noticeable.

Nancy Ames, an oat and cereal grain expert with Agriculture Canada in Winnipeg, was surprised by the Grain Millers announcement. She has never heard of glyphosate compromising oat quality.

“I’ve looked through all of the literature and there’s really nothing out there on this,” Ames said. “There has been some research on spraying glyphosate… and its effect on the quality of wheat…. There were some effects on increasing protein and it may have reduced starch.”

Jarrod Firlotte, general manager of Emerson Milling, an oat processor in Emerson, Man., said he hasn’t witnessed any oat problems related to glyphosate.

“It certainly hasn’t been an issue for us. I can’t say I’ve heard a lot of talk about it,” he said. “We have no plans of changing the way we do things.”

On top of the changes to performance and texture, Grain Millers said they discovered that pre-harvest glyphosate was affecting beta glucan levels in the oats.

Beta glucan is a soluble fibre linked to improvements in cholesterol levels and cardiovascular health. Food manufacturers can place a “Heart Healthy” claim on oat-based cereals because they contain beta glucan.

Tyson said an early application of glyphosate causes a shortcut to crop maturity, which may decrease the amount of beta glucan in the oats.

“In order to meet those (Heart Healthy) claims, beta glucan levels in the raw oats (has) to be in excess of four percent.  Other factors can also adversely affect beta glucan levels, but our research demonstrates that premature application of glyphosate can have that effect.” 

Tyson said it appears the timing of glyphosate desiccation is critical.

“The application of glyphosate, if it’s done correctly, we don’t think it causes the same problem,” he said. “Possibly too high a rate, but too early is the biggest culprit.”

  • March 20: International Agency for Research on Cancer, of the World Health Organization, publishes review of laboratory and epidemiological studies on glyphosate. IARC classifies glyphosate as ‘probably carcinogenic to humans.’
  • April 13: Health Canada Pest Management Regulatory Agency issues proposed re-evaluation decision for glyphosate. PMRA scientists say glyphosate is not a health risk when used according to label directions.
  • April 17: The U.S. Environmental Protection Agency says it may recommend testing food products for glyphosate residues. The U.S. has not previously tested food for the popular herbicide because glyphosate was perceived as safe.

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