Sprayed Before Harvest: Desiccant Herbicides in Our Grain

Oct 14, 2026 · @Thomas Abshier

Some wheat, oats, beans, and other grains that reach your table were sprayed with an herbicide about a week before harvest. The spray does not help the crop grow. It kills the plant so the field dries down evenly and the combine can run on schedule. The practice is called preharvest desiccation, and on October 13, 2026, Dr. Robert Malone and Dr. Jill Glasspool Malone published a proposal in Malone News asking the President to phase it out over three years.

I want to walk through their argument, add what I see as a physician, and be clear about where the evidence is strong and where it is still open. My conclusion is that they are right on the central point: a chemical exposure that isn’t needed to produce the food should carry the burden of justification.

What preharvest desiccation is

A grain crop near maturity is not uniformly ripe. Some heads are dry, some stems are still green, and late weeds may be growing through the canopy. Traditionally, farmers either waited for the field to dry on its own or cut the crop into windrows (swathing) to dry on the ground before combining.

Desiccation replaces that waiting with a spray. The herbicide kills whatever is still green, and within days the field is ready. The chemicals used include glyphosate (the active ingredient in Roundup), paraquat, diquat, sodium chlorate, saflufenacil and carfentrazone, depending on the crop and what its label allows.

The benefit is to the harvest schedule, not to the grain. A mature wheat plant makes no more kernels because it was sprayed. That distinction is the hinge of the whole argument.

How it became routine, and what we don’t know

Preharvest glyphosate use took hold in northern grain regions in the 1980s and 1990s. Charles Benbrook’s 2016 analysis traced a rise in these “harvest-aid” applications from the mid-2000s, especially on wheat, barley, and edible beans in the northern states.

Over the same period, total U.S. agricultural glyphosate use rose from roughly 7.7 million pounds in 1990 to nearly 250 million pounds in 2014. Most of that growth came from weed control in herbicide-tolerant crops, not from desiccation. The Malones are careful to say so.

Here is the problem. USDA surveys record which herbicides go on which crops and in what amounts, but the public national summaries do not reliably separate a preharvest spray from a spring weed treatment. So no one can confidently say what share of American wheat or oats is desiccated in a given year. We should count a practice that puts chemicals on food a week before harvest. That alone would be a modest and useful reform.

Why the timing matters

A May spray has months to break down, wash off, and be diluted by growth before the grain is cut. A spray seven days before harvest does not. Some glyphosate labels allow application to mature wheat with a seven-day interval before harvest.

Glyphosate is also systemic: the plant takes it up and moves it through its tissues, including toward the seed. Washing or rain cannot remove what is inside the kernel. Paraquat and diquat act differently, as contact killers, and each chemical has its own residue profile, so the risks should not be lumped together. But the question is the same for all.

The legal ceilings on glyphosate residue have risen as these uses expanded. Under 40 CFR §180.364, the tolerances the Malones cite are:

Commodity	Tolerance in 2000 (ppm)	Current tolerance (ppm)
Wheat grain	5	30
Oat grain	20	30
Field corn grain	1	5

These are the maximums allowed by law, not what you typically find on store shelves, and not every increase is due to desiccation. Still, a tolerance answers only one question: is this much residue acceptable? It does not ask whether the residue needed to be there at all. That second question is the one EPA has not systematically asked, and it is the right one.

What the human evidence shows, and what it doesn’t

Exposure is nearly universal. CDC researchers (Ospina et al., 2022) found glyphosate in the urine of about 81 percent of Americans sampled in the 2013–2014 NHANES survey. Glyphosate did not exist in commerce before the 1970s.

The studies that follow from that exposure point in a consistent direction, but they are early:

• Pregnancy and birth weight. Gerona et al. (2022) found glyphosate in 186 of 187 pregnant women in an Indiana high-risk cohort; higher first-trimester levels were associated with lower birth-weight percentiles.
• Newborn development. Lesseur et al. (2021) reported associations between maternal AMPA (glyphosate’s breakdown product) and anogenital distance in female infants, though some glyphosate associations did not hold after adjustment.
• Metabolic disease. Li et al. (2023) used NHANES data to associate higher urinary glyphosate with type 2 diabetes, with lower HDL cholesterol accounting for a small part of the link.
• Animal work. Rodent studies report changes in ovarian hormone production, sperm development, and endocrine signaling, and one 2024 study found glyphosate combined with 2,4-D worsened reproductive effects of a Western-style diet.

The human studies are observational: they show association, not cause. None of them can tell us how much exposure comes from desiccation versus other uses. Many animal studies used doses or commercial formulations that do not map neatly onto dietary residue. The cancer question remains contested between IARC and the regulatory agencies.

But uncertainty cuts in a particular direction here. When an exposure is optional, unresolved safety questions are a reason to remove it, not to keep it until harm is proven. We don’t require proof of injury before removing an unnecessary drug from a patient’s list.

Beyond the dinner plate

Herbicides leave the field through runoff, drainage, erosion, and drift. USGS monitoring has found glyphosate in American streams and rivers, and EPA’s own ecological assessments flag risks to non-target plants and animals from paraquat and diquat. Aquatic plants and algae are especially exposed, since these chemicals are built to stop plant growth.

Soil is a living system of bacteria, fungi, nematodes, and earthworms that cycle the nutrients our food is made from. Research shows glyphosate can shift soil microbial communities. In naturopathic medicine, we think in terms of terrain, in the body and in the ground. A late-season spray that adds to the chemical load on both, for convenience, is hard to defend.

The farmer’s side

Farmers did not adopt desiccation out of carelessness, and any honest case has to explain why.

• Short, wet seasons. In northern states and the Canadian prairies, a crop left standing into a rainy fall can sprout in the head, mold, lodge (fall over), or be lost to an early snow. Desiccation shortens that window of risk.
• Green weeds at harvest. Late weeds can jam combines and raise grain moisture, which costs money in drying or price docks.
• Cost and labor. Swathing is an extra pass with extra equipment, and mechanical drying burns fuel. Margins in grain farming are thin.
• Regulators say it’s safe. The EPA says residues within tolerance pose no meaningful risk.

These are real. They also argue convenience and cost, not whether the crop can be grown and harvested without the spray. Organic grain farmers do it every year. Corn, the largest U.S. grain crop, is mostly left to dry in the field. Where the weather risk is genuine, a narrow, documented exception is better than a routine practice. And a three-year transition with USDA help is a reasonable way to absorb the cost.

One caution on mechanics: an Executive Order cannot by itself ban a registered pesticide use. Under federal pesticide law (FIFRA), EPA must go through notice, comment, and a cancellation or label-amendment process, and registrants can contest it. An order can set the policy and deadline and direct the agencies to begin. That is what the Malones propose, and it is realistic.

The proposal: a three-year phaseout

The Malones ask for an Executive Order under the Make America Healthy Again initiative directing EPA and USDA to end routine preharvest desiccation of food crops. It is deliberately narrow: no ban on herbicides for in-season weed control, no interference with no-till farming, no new cultivation system.

1. Year one. EPA opens the regulatory process to withdraw desiccation uses from pesticide labels. USDA works with growers, extension services, and equipment makers, and farmers get advance notice.
2. Year two. Restrictions take effect first for crops where non-chemical harvest methods are readily available, with technical help from USDA.
3. Year three. EPA completes actions to end routine desiccation on food crops. Any emergency exception must be specifically justified.

Alongside the phaseout, they ask agencies to measure how many acres are desiccated now, compare residues in treated and untreated crops, track human exposure and stream contamination as the practice ends, and review whether past tolerance decisions ever considered the availability of non-chemical harvest. That research would document the results without becoming a reason to delay.

I support this proposal. It removes one identifiable source of exposure, asks nothing of farmers that their grandfathers didn’t already do, and puts the burden of proof where it belongs. Their article lists contacts at the White House, EPA’s Office of Pesticide Programs, USDA, and HHS for readers who want to write in.

What you can do now

Policy takes years. Your kitchen does not.

• Buy organic for the desiccated crops. Oats, wheat, barley, lentils, chickpeas, and dried beans are the foods most often desiccated. Certified organic rules prohibit synthetic preharvest herbicides. If you buy organic for only a few items, start with oatmeal, breakfast cereals, bread and flour.
• Look for residue testing. Some brands carry a third-party “glyphosate residue-free” certification. It is not the same as organic, but it tests the finished product.
• Prioritize pregnancy and young children. The developmental studies, though early, concern exactly these groups, and children eat more grain per pound of body weight.
• Eat whole and varied. A diet built on vegetables, fruit, quality protein, and a variety of grains spreads out any single exposure.
• Support the gut. Fiber, fermented foods and adequate hydration support normal elimination, and the microbiome is one system the glyphosate literature is watching.

None of this calls for fear. It calls for proportion: reduce an avoidable exposure where it is easy, and support a policy that would reduce it for everyone.

References

1. Malone JG, Malone RW. Stop Spraying Poison on Our Food Before Harvest. Malone News (Substack). October 13, 2026.
2. Benbrook CM. Trends in glyphosate herbicide use in the United States and globally. Environmental Sciences Europe. 2016;28:3.
3. U.S. EPA. Glyphosate; Tolerances for Residues. 40 CFR §180.364.
4. Ospina M, et al. Exposure to glyphosate in the United States: Data from the 2013–2014 NHANES. Environment International. 2022;170:107620.
5. Gerona RR, et al. Glyphosate exposure in early pregnancy and reduced fetal growth. Environmental Health. 2022;21:95.
6. Lesseur C, et al. Maternal urinary levels of glyphosate during pregnancy and anogenital distance in newborns. Environmental Pollution. 2021;280:117002.
7. Li W, et al. Association of glyphosate exposure with multiple adverse outcomes and potential mediators. Chemosphere. 2023;345:140477.
8. Chitolina R, et al. Subacute exposure to Roundup changes steroidogenesis … in rat ovaries. Toxicology and Applied Pharmacology. 2023;473:116599.
9. U.S. EPA. Preliminary Ecological Risk Assessment for the Registration Review of Paraquat. June 26, 2019.

This article is for general education and is not individual medical advice.