Brett Blankenship, a wheat grower from Washtucna, Wash., and president of NAWG said the claims that glyphosate was being dumped on wheat crops are not true.

KANSAS CITY — The National Association of Wheat Growers (NAWG) has countered claims on the Internet that growers were “drenching” wheat crops with glyphosate shortly before harvest.

“The concern that Roundup is being dumped onto wheat plants is just patently not true,” Brett Blankenship, a wheat grower from Washtucna, Wash., and president of NAWG, told Milling & Baking News. “We’re very sensitive that we are the front line in the production of a consumer product. We’re very aware that we produce a food product. That’s why we are very careful.

“We know it’s a safe product to use according to the label. That’s the way we use it. It would not wind up in any consumer product.”

The apparent source of the Internet “blowup” of accusations that the use of glyphosate, commonly referred to as Roundup, a popular herbicide from Monsanto Co., was making wheat toxic was a Nov. 13, 2014, article by Sarah Pope, writer of The Healthy Home Economist blog, titled “The real reason wheat is toxic (it’s not the gluten).” Ms. Pope holds a bachelor’s degree in economics from Furman University and a master’s degree in government administration from the University of Pennsylvania and worked 10 years in information technology before becoming a food blogger and author.

“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,” Ms. Pope wrote. “Pre-harvest application of the herbicide Roundup or other herbicides containing the deadly active ingredient glyphosate to wheat and barley as a desiccant was suggested as early as 1980. It has since become routine over the past 15 years and is used as a drying agent 7-10 days before harvest within the conventional farming community.”

Ms. Pope supports her article with comments from Stephanie Seneff, Ph.D., of the Massachusetts Institute of Technology, and from two wheat farmers. Dr. Seneff claims that wheat exposed to glyphosate “releases more seeds resulting in a slightly greater yield.”

“In a nutshell, Dr. Seneff’s study of Roundup’s ghastly glyphosate, which the wheat crop in the United States is doused with uncovers the manner in which this lethal toxin harms the human body by decimating beneficial gut microbes with the tragic end result of disease, degeneration and widespread suffering,” Ms. Pope said in her Dec. 13 blog.

Numerous experts cited multiple discrepancies in Ms. Seneff’s comments, including the claim that glyphosate applied shortly before harvest caused wheat plants to produce more kernels, when in fact the plant would be mature and longer in a reproductive phase. They also noted that a mature wheat plant could not absorb glyphosate. The product works by being absorbed by green plants.

Ms. Pope also cited U.S.D.A. data saying that 99% of durum, 97% of spring wheat and 61% of winter wheat were treated with herbicides as of 2012, compared with 88%, 91% and 47%, respectively as of 1998, implying that glyphosate use has increased, although there is no reference to glyphosate in the numbers.

Mr. Blankenship noted that 70% of wheat acres don’t receive any Roundup, and where it is used, it’s mainly for conservation purposes in no-till fields. He noted that Roundup is used for fallow applications on his wheat acreage, applied more than a year before the crop is harvested. Most farmers who do use Roundup or another herbicide for weed control do so mostly near planting before the wheat emerges, he said.

Ms. Pope’s story was quickly quoted by numerous anti-glyphosate, anti-Monsanto crusaders as “proof” of such use of the herbicide. Numerous other bloggers and studies have decried that the extensive use of glyphosate contributes to diseases such as Alzheimer’s, cancer, diabetes, celiac, gluten intolerance and others.

“Many conventional wheat farmers in America, driven by greed and carelessness, flood their wheat crops with Roundup just before harvest in order to slightly boost yields and reduce harvest time,” said Ethan A. Huff, in Global Research on Dec. 12, 2014. “But the end result is Roundup being absorbed directly into the wheat kernels that end up processed on your dinner plate.”

NAWG is attempting to counter the Internet accusations with five articles titled “The truth about glyphosate” on it’s the Word on Wheat blog.

“Broadly speaking, glyphosate use is limited in the wheat industry, if even used at all in some wheat fields,” NAWG said on its blog. “In fact, it is applied to less than 30% of wheat acres in the U.S., according to an independent consumer research firm, GfK.”

NAWG notes that an increase of no-till wheat production to reduce soil erosion and moisture loss in the Great Plains over the last 26 years has “led to an observed increase of glyphosate use in the industry … however, applications are still low compared to other commodity crops.”

There are four times glyphosate tends to be used in wheat production, NAWG said, with the two most common being before, the first being at and after planting but before wheat emergence and the second to control weeks during fallow, when no crop is growing.

A third approved use (the one attacked by Ms. Pope) of glyphosate is “Pre-harvest applications made seven days or more prior to harvest as a harvest aid to dry green weeds and even the maturity of a wheat crop so that it may be harvested before end of season frosts occur. This is highly uncommon treatment used in less than 2% of wheat acres; however, it can be used to enable a harvest that would otherwise not be possible.”

“I have not heard of any reports of an increase over the norm,” Mr. Blankenship said when asked if he had heard of increased use of Roundup before harvest this year because of weed problems resulting from ample moisture, especially in soft red winter wheat areas.

A fourth use is referred to as “crop destruct” made to a growing wheat crop when weeds, insects, disease or adverse weather negate a viable crop, which results in no harvestable grain.

“We’re just trying to respond to the public’s lack of understanding of how this product is used and what it is used for,” Mr. Blankenship said of NAWG’s response to the flurry of Internet activity. “We live in a time when if you don’t respond to things that aren’t true, then it’s assumed that it might be.”

The World Health Organization’s International Agency for Research on Cancer (I.A.R.C.) presented summary findings in March stating that glyphosate (and insecticides malathion and diazinon) were “probably carcinogenic to humans based on convincing evidence that these agents cause cancer in laboratory animals.”

Monsanto countered, noting U.S. Environmental Protection Agency statements that glyphosate poses no cancer risk to humans when used correctly. Roundup has been on the market for more than 40 years. Monsanto has commissioned an independent review of the I.A.R.C. study by at least 10 experts provided by the Canadian division of Intertek Scientific and Regulatory Consultancy.