Sponsored By
Farm Progress

Toxic wheat claims are inflammatory, irresponsible and falseToxic wheat claims are inflammatory, irresponsible and false

Misinformation about potential toxicity of U.S. wheat has been spreading through social media, leading to confusion and fueling anxiety.

December 9, 2014

5 Min Read
<p>In 2014, Oklahoma suffered its worst wheat crop since 1957, harvesting only 47 million bushels. Prior to 2014, the 5-year Oklahoma average was to harvest nearly 116 million bushels annually.</p>

Social media’s self-appointed food experts are doing a hatchet job on American wheat.

Misinformation about potential toxicity of U.S. wheat has been spreading through social media, leading to confusion and fueling anxiety.

The claims are inflammatory, irresponsible and false.

“Wheat in whole form or enriched is central to a healthy diet for the general population and should only be avoided by those clinically diagnosed with celiac disease, gluten insensitivity or a wheat allergy,” said Jeff Edwards, Oklahoma State University Cooperative Extension small grains specialist.

OSU Wheat Genetics Chair Brett Carver agreed, saying wheat remains as natural and true to its heritage as any major food-producing plant.

“Thousands of years of evolution and adoption by human civilizations have made it that way. No other cereal grain has as much dependency on its ancestors and non-cultivated relatives, what the general public may call ‘ancient grains,’ to fuel the development of new and resilient varieties,” he said. “What is changing are some of the techniques – yet still involving natural interpollination – that enable scientists to more efficiently tap those same genetic resources without losing ground to the growing demands of modern society.”

Unfortunately, the blog post that started the recent bout of anxiety and misinformation claimed “common wheat harvest protocol in the United States is to drench the wheat fields with Roundup several days before the combine harvesters work through the fields as the practice allows for an earlier, easier and bigger harvest.”

“Wheat farmers do not ‘drench’ fields with pesticides,” said Angela Post, OSU Cooperative Extension weed scientist. “Application of any pesticide is expensive to the farmer, who already has a tight economic bottom line with little margin for error. A glyphosate application could cost as much as $6.50 per acre just for the chemical.”

For a typical wheat field in the southern Great Plains states, it represents an additional $3,500 in costs that a typical farmer will likely choose not to incur. Furthermore, the common use-rate for glyphosate, the active ingredient in Roundup, is about one quart per acre.

“This is equivalent to evenly and accurately spreading one quart of liquid over a football field,” Edwards said. “Even considering the 10 gallons of water that would be used to dilute the glyphosate for spraying, a more accurate description would be an ‘extremely light mist’ rather than ‘drench.’ This practice might be used occasionally to facilitate wheat harvest and to produce grain that is less contaminated by weeds present at harvest.”

In short, although specific situations may call for a glyphosate application, it is not a common practice of wheat farmers. Edwards, Carver and Post contend a reasonable estimate of the U.S. wheat acreage under this practice would be between zero percent to 10 percent in a given year.

“Many herbicides have labels that allow them to be used as harvest aids or desiccants,” Post said. “Label guidelines are determined through years of testing and require Environmental Protection Agency approval. Glyphosate is labeled for pre-harvest weed control in specific scenarios.”

But what about the “glyphosate residue laden wheat kernels” cited in the original blog post titled “The Real Reason Wheat is Toxic” by the Healthy Home Economist?


Post said the grain is not exposed prior to harvest, when the herbicide might be applied, because individual grains are encased by mother plant tissue called the lemma and palea, which in turn are encased by the outer glume layer.

“Think of the glume as an envelope covering the seed from the elements and holding it in place until harvest,” she said. “The threshing process in the combine separates the grain from these maternal tissues otherwise called chaff. Even with whole wheat the chaff is not consumed with the grain.”

Americans main protection from herbicide residues in food is the EPA’s residue limit set for each commodity where pesticides are likely to be present. In this specific case, EPA does not set a tolerance for wheat flour or other wheat products because glyphosate residues do not concentrate in the grain.

“To give an example, sweet corn has a residue limit of 3.5 parts per million, which is the amount of glyphosate allowable on this product at the time of purchase,” Post said. “Studies investigating glyphosate residues on wheat as soon as three days after application recovered 20 times less glyphosate than the EPA allowable tolerance on a food – sweet corn – commonly eaten by consumers.”

What about the blog’s claim that agricultural producers are “drenching” crops with herbicides? According to U.S. Department of Agriculture data, total pesticide use in the United States peaked in 1981 and then began to steadily decrease. This is true for insecticides, fungicides and herbicides such as glyphosate.

“Herbicide use has remained relatively stable since the mid-1990s,” Edwards said. “Furthermore, the U.S. wheat crop accounts for only 4.5 percent of the total amount of pesticides applied nationwide.”

It is important to note that most glyphosate used at harvest time is done on spring and durum wheat, and mostly in northern-tier states such as North Dakota and Montana, as well as some Canadian provinces. Approximately 75 percent of U.S. wheat acres are winter wheat, and pre-harvest glyphosate application is very uncommon on winter wheat.

“Commercial supplies of wheat grain are subject to government regulations extending from the farm to the storage facilities and into the bakery,” Edwards said. “This intense level of scrutiny is intended to give us as consumers the confidence we need to enjoy, and not to avoid, one of nature’s treasured grains. Avoidance is typically advised only in the case of a known medical condition linked to digestibility.”

Subscribe to receive top agriculture news
Be informed daily with these free e-newsletters

You May Also Like