Confusion around glyphosate (commonly known as Roundup) and its use in wheat farming has sparked concern among consumers. Is wheat “drenched” in chemicals, or pesticides, before harvest? Are glyphosate residues harming our health? Let’s separate fact from fiction.
What Is Glyphosate?
Glyphosate is a widely used herbicide that helps farmers control weeds. It’s been used for decades in crops like corn, soybeans and wheat. In wheat farming, it’s typically used to control weeds before or immediately after the wheat is planted. It can sometimes applied before harvest, but only under specific conditions.
How is Glyphosate Used in Growing Wheat?
There are four potential uses for glyphosate in wheat, with the first two listed as most common:
- Applications before planting, at planting and after planting, but before wheat emergence ensures minimal weed competition occurs throughout the growing season. This practice is most common in no-till systems.
- Fallow applications, as mentioned previously, are made following harvest when no crop is present to keep weeds from using precious soil moisture. This is most commonly practiced in the Western United States and semi-arid wheat producing regions.
- Pre-harvest applications made after the wheat plant has shut down, when wheat kernel development is complete and the crop has matured. This is prior to harvest and used to dry green weeds and allow the crop to even its maturity. This is an uncommon treatment used in less than 3 percent of all wheat acres; however, it can be used to enable a harvest that would otherwise not be possible, if weather conditions prevent the wheat crop from drying sufficiently to be harvested.
- “Crop destruct” applications are made to a growing wheat crop when weeds, insects, disease or adverse weather preclude the ability to produce a viable crop. This, of course, results in no harvestable grain.
Is Wheat Sprayed with Roundup Before Harvest?
Sometimes, but not usually
Glyphosate may be used at the hard dough stage, when the wheat grain is fully mature and no longer absorbs nutrients or chemicals. Farmers use it to:
- Control late-season weeds
- Help the crop dry down evenly
- Improve harvest efficiency in wet or weedy conditions
This practice is more common in northern regions like Canada and the northern U.S. and rarely used in places like Kansas, Texas, Colorado, Oklahoma or Nebraska, where winter wheat dominates.
Is It Safe?
Yes, when used properly and according to label instructions:
- The EPA sets strict residue limits for glyphosate in wheat (30 parts per million)
- Farmers must observe a minimum 7-day waiting period before harvest
- Wheat kernels are protected by a natural husk called a glume, which is removed during processing and further reduces residue risk
Myth Busting
| Myth | Fact |
| Wheat is drenched in Roundup | Glyphosate is used selectively and sparingly |
| Glyphosate enters the grain | The grain is shielded by a husk and not absorbent at maturity |
| Glyphosate causes gluten sensitivity | No credible evidence links glyphosate to digestive disorders |
Myth #1: Wheat is drenched in glyphosate before harvest
Fact: Glyphosate is not routinely sprayed on wheat before harvest. In the U.S., especially in winter wheat regions like Kansas and Oklahoma, pre-harvest use is rare. When it is used, it’s applied only after the grain is fully mature and no longer absorbs chemicals.
Myth #2: Glyphosate enters the wheat grain and contaminates food
Fact: Mature wheat kernels are protected by a natural husk (the glume), which shields the grain from external substances. Residue testing consistently shows glyphosate levels in wheat are well below EPA safety thresholds.
Myth #3: Glyphosate causes gluten sensitivity or celiac disease
Fact: There’s no credible scientific evidence linking glyphosate to gluten-related disorders. Gluten sensitivity and celiac disease are autoimmune and digestive conditions unrelated to herbicide exposure.
What Do Recent Studies Say?
New research is exploring glyphosate’s long-term health effects. A 2024 study from Arizona State University found that short-term exposure caused brain inflammation and Alzheimer’s-like symptoms in mice. While these findings are concerning, they don’t reflect typical consumer exposure levels from wheat products.
The bottom line: more research is needed, but current regulations and farming practices keep glyphosate residues in wheat well below safety thresholds.
Learn More
National Association of Wheat Growers, The Facts About Glyphosate
- Part 1: How Do Wheat Growers Use Glyphosate? Wheat growers primarily use glyphosate before planting or after harvest to control weeds, especially in no-till systems that help preserve soil moisture. Regulatory agencies worldwide have concluded that glyphosate, when used according to label directions, poses no unreasonable risk to human health or the environment.
- Part 2: Growing a Quality Wheat Crop with Glyphosate Wheat growers use glyphosate strategically to manage weeds and prevent diseases like wheat streak mosaic virus, which can severely impact crop quality and yield. Only a small percentage of U.S. wheat acres receive glyphosate pre-harvest treatment, and these applications occur after the crop has matured, ensuring grain safety and compliance with EPA residue limits.
- Part 3: How Does USDA Collect Farm Data? The USDA collects farm data on pesticide use, including glyphosate, through NASS, which surveys farmers about agronomic practices on a rotating schedule. These surveys focus on usage trends and quantities, not application timing, while other sources provide more detailed insights into when (before planting) and how glyphosate is applied across wheat acres.
- Part 4: Why Does USDA Collect Farm Data? The USDA collects farm data to support food safety, environmental protection and informed decision-making across agriculture, trade and conservation. By gathering confidential, voluntary input from farmers, the agency helps quantify benefits of practices like no-till farming and ensures accurate assessments of pesticide impacts.
- Part 5: Recap Glyphosate is used on roughly 30% of U.S. wheat acres, mostly before crop emergence, with pre-harvest applications limited to about 2% of acres and only after the wheat has fully matured. Studies show that glyphosate residues in harvested wheat remain well below EPA safety thresholds, supporting its responsible use in modern farming practices.
Oklahoma State University, Glyphosate Use as a Pre-Harvest Treatment: Not a Risk to Food Safety
- Glyphosate is occasionally used as a pre-harvest treatment in wheat to manage late-season weeds and improve harvest efficiency, especially in wet conditions. When applied after the crop is fully mature and according to label guidelines, the grain remains protected by its husk, and residue levels stay well below EPA safety limits.
Kansas Wheat, The Truth about Roundup in Wheat
- Roundup (glyphosate) is not routinely used as a pre-harvest treatment in U.S. winter wheat production; most applications occur before or shortly after planting to manage weeds. Experts confirm that claims of widespread pre-harvest spraying are misleading, and scientific evidence supports the safety of glyphosate when used according to label guidelines.
Food and Drug Administration, Questions and Answers on Glyphosate
- Glyphosate is a herbicide that blocks a key enzyme in plant growth, and the EPA has set strict residue limits on food crops to ensure safety. The FDA monitors glyphosate residues in domestic and imported foods, consistently finding levels well below regulatory thresholds, with no evidence of risk when used according to label directions.
Final Thoughts
Wheat farmers are committed to growing safe, nutritious food. Glyphosate is one tool in their toolbox, used responsibly and only when needed. If you’re concerned about food safety, the best thing you can do is stay informed and ask questions grounded in science.