It’s time to curtail pre-harvest glyphosate

Glyphosate is under siege nationally and internationally. Stopping its pre-harvest use might be a logical step to quell the uprising and preserve the world’s most popular herbicide for other applications.

This wouldn’t stop activists from railing against what they view as an evil cancer-causing poison, but it would go a long way to addressing the issue of glyphosate residues in food.

The general public doesn’t understand and probably can’t be made to understand the concept of maximum residue limits. For them, any level of weed killer in their bagel, doughnut or hummus is too much. It just shouldn’t be there.

It doesn’t matter if it’s a part per million, per billion or per trillion. It doesn’t matter if the level is one-tenth what’s deemed as acceptable and safe. It’s hard to argue with a general population that’s scientifically illiterate.

The vast majority of the measurable glyphosate in harvested crops is the result of pre-harvest applications. Glyphosate used as a weed burn-off before seeding shouldn’t be an issue, and early season application to glyphosate-resistant crops should not be a source of measurable residue, either.

It’s the application leading up to harvest that causes measurable residues. Producers are being told not to apply until crops are below 30 percent moisture, but not everybody follows that advice. As well, maturity can be highly variable across a field.

Officially, glyphosate is not considered a desiccant. Pre-harvest use is supposed to be for the control of perennial weeds, not for crop dry down. However, not every producer views it that way. Frankly, glyphosate is over-used and carelessly applied all too often because it’s comparatively cheap.

Back in the 1970s and 1980s, Roundup was $24 a litre and was only cost effective for spot applications. If you’re old enough, you may remember Focus on Inputs, led by Ken Goudy of Melfort, Sask., which tried to establish a generic Roundup manufacturing facility. Those were the days before Roundup Ready canola.

It was Goudy who first told me about the potential to use glyphosate pre-harvest, saying this use was common in Europe. At the time, it seemed strange to be spraying a weed killer on a crop not long before putting it in the bin.

When Roundup came off patent and generic manufacturing drove the price down, use skyrocketed. For farmers, the main worry has been the rise of glyphosate-resistant weeds. Now we should be worried about losing the chemistry altogether.

The international report labelling glyphosate as a probable carcinogen has been widely discredited, but the damage has been done.

We will see more and more food companies stipulating that they don’t want grain in which glyphosate has been applied pre-harvest. Unfortunately, pre-harvest use is so common in some areas that tiny amounts of glyphosate might be measurable even in crops that weren’t sprayed.

You hate to give in to the activists and fear mongers. Nothing short of a complete ban would make them happy. And yes, pre-harvest glyphosate is a great tool and it would be sorely missed. Many farming practices would have to adjust. Swathing crops might even make a comeback.

But maybe it’s time to be proactive — better to forego one use for glyphosate than risk having all uses further stigmatized. Eliminating or at least drastically reducing glyphosate residues in food could be accomplished if pre-harvest use ended.

Kevin Hursh is an agricultural journalist, consultant and farmer. He can be reached by e-mail at

About the author


  • richard

    Yes its hard to argue with a public who is scientifically illiterate…. Its even harder to argue with a producer who consumes nothing he produces, yet wonders why others don’t want to eat it either???

    • Happy Farmer

      As a farmer and consumer I don’t know where you get the idea farmers don’t eat what they produce. I, and most likely all other farmers buy their groceries at the same stores as everyone else.
      It also seems from my viewpoint that you assume farmers are just blindly doing what “The Company” tells us. How many farmers have you had a discussion with to verify your view?

      • richard

        Sorry, I didn’t say anything about your blind subservience to “the company”….. but if the shoe fits wear it…? How many producers do you know that grind their own wheat and durum for bread and pasta? How many do you know that make curry, hummus and falafel from their lentils and chickpeas? How many raise a hog or even some chickens let a alone a garden to produce winter food? Thats right, less than one percent….. The balance complain about low price of commodities…..and the high price of food??? Furthermore do you guys really believe the public is unaware that while you are out desiccating your wheat, durum, barley, oats, lentils, peas and chickpeas…. you have no desire to eat any of them? But its the consumer how is “ignorant and misinformed” right? As long as you guys continue thinking nothing but commodity, you will find yourself increasingly being treated as one yourself.

        • Happy Farmer

          I see by your response you did not read my response very well. As usual comments made are only to question and provide no real interaction.

          Ill try again in simpler terms. I am a farmer. I (my wife) shops at most major grocery chains for our food. All farmers I know do the same shopping. Therefore, we as farmers are eating the same food as the majority of others are. We are not scared of eating what we produce, whether from the farm or grocery store.

          I and most farmers I know are not “blindly” following what we are told. The complexities of how we make daily decisions are not worthy of explanation to anyone. They are ours alone to make. This is why we are very aware of how easily anyone can be misled in todays’ world. This applies to each one of us, whether we are farmers or consumers. One thing I know for sure, each of us must always be willing to look beyond our bias in order to “walk in the other persons” shoes. Yes, that applies to me and you. So I respectfully ask myself – How many consumers have I talked to? And again, I respectfully ask you – How many farmers have you talked to?

          • richard

            Thank you for making my point for me….. farmers do not eat what they produce….they buy groceries at the store, which hardly inspires confidence with city consumers…..If producers will not eat what they desiccate why should anyone else?…..Your “complexities of daily decisions….not worthy of explanation” attitude, is precisely why consumers push back for transparency in food production…. Furthermore why do I constantly hear farmers complaining about the low price of commodities and the high price of food? What an absurd dichotomy… Until farmers learn to grow their own food again they will continue be treated like the commodities they produce…

          • Happy Farmer

            If the food supply is as bad as you say, why would I (and other farmers) eat from it? If my crop has been desiccated, processed and sold in a store, am I not eating the same food as others? SO, Farmers are eating the same food as everyone else, not sure why this is not understood by some…!!.. Maybe I will make a special t-shirt for my grocery shopping days that says “Proud to eat what I produce”. That should start a great conversation where I can inform people of fact based science.
            I did not say I wont talk about how I raise my crops, just not about how hard it is today to make daily decisions that are workable for all, especially my profitability.

          • richard

            Yeah and if the food supply was so clean why would you and millions of dollars annually be required to defend it over and over and over with the same lame platitudes? ……Truth smacks, it never requires wishful thinking to drive it…. Glyphosate has achieved biological obsolescence (thirteen weed species on sixty million acres USDA)…. It has been abused and is about to become a footnote in the annals of agricultural hubris….. Sorry, there is no defence for willful ignorance other than more willful ignorance ie. herbicide stacking. This is why reactionaries spend their entire lives reacting, with denial ad nauseum

          • Happy Farmer

            Why do I and others defend our food supply?…Because there is a concerted effort out there by a vocal minority to discredit it…..Same lame platitudes-true on both sides.

  • Welderone

    European scientists have found glyphosate to be an unsafe product. France has already put a deadline on the use of grain farmers in their country from using glyphosate. Germany is now in the process of banning glyphosate. So anyone living in Europe is scientifically literate when it comes to the use of glyphosate. As people in Canada are also when they agree with the European scientists. As far as grain farmers that are pro glyposate. I think Kevin has given you the main reason in his article. Comparatively cheap.

    • Verna Lang

      European scientist have found glyphosate to be unsafe? Did I miss Switzerland leaving Europe recently? Because scientists working for the Swiss Federal Office for Food Safety and Veterinary Affairs (FSVO) found that glyphosate levels are not a health risk. They concur with the scientists of the German BfR and the EU’s EFSA. The following is from the announcement of the results of a study carried out by the Swiss scientists:

      The results of the study are reassuring
      In this study, 243 food samples were collected from the retail trade in Switzerland and analyzed. These were mainly foods in which glyphosate residues were expected to be found, namely grain products and legumes.

      60% of these samples did not contain glyphosate. The remaining samples contained them but in very low concentrations and well below the maximum limit allowed. Therefore, these foods do not pose a health hazard. These residues would be dangerous for health if you consume eg 72 kg of pasta, 655 kg of bread, 10 kg of chickpeas or 1600 liters of wine per person per day.

      Unlike other countries, Switzerland prohibits the treatment of fields with glyphosate just before harvest. As expected, Swiss products were contaminated but to a much lesser extent. The study also showed high concentrations in imported cereal products such as durum wheat pasta and pulses. But even in these foods, the residue content was below the maximum allowable levels and therefore did not pose a health hazard.

      (Bold added for emphasis)

      A word of caution about the 1600 liters of wine per day. The ethanol will kill you long before you can get remotely close to that 1600 liters of wine. But why should anyone worry about a known carcinogen and poison like ethanol when there is glyphosate to panic about?

      • Happy Farmer

        Thanks for posting that information.

        As a farmer I would be in favor of reducing any or all of the practice of desiccation. Sidenote, I do not desiccate any crops.

        • Verna Lang

          Dessication with glyphosate only makes sense in northern climates where it comes to a choice between losing your harvest to ice and snow or not. If used as directed, the glyphosate is applied only after the seeds or part being used for food is dry to the point where they are incapable of taking up anything applied to the plant. Making sure farmers are educated about that application method is where the efforts should be made, not spreading ignorance and fear about something that does not happen with the majority of the harvest.

          • richard

            So why does it end up in the seeds of crops that have been desecrated?…..Lentils, peas, oats, barley and durum come to mind…..just an accident I guess? … And why do the companies who process these crops warn against/prohibit the use of glyphosate as a growth regulator…. just a coincidence I guess?….One thing I know is that the deflect, deny and denigrate approach of industry apologists is only hastening the demise of their favourite drug…..

          • Verna Lang

            Look at the discussion from the study done in Switzerland from my original comment. Remember they chose foods most likely to have traces of glyphosate. Just because something is detected in food with a sensitivity that didn’t even exist a decade or so ago does not mean it is a dangerous amount.
            If you are spreading fear about traces of glyphosate, you are being a useful idiot for ambulance chasing litigation lawyers in the US. In their case, they are chasing ambulances in private jets. Where do you think all the money for testing and spreading fear, uncertainty and doubt about those glyphosate results in the media comes from? Or do you think those multi-millionaire lawyers are doing this out of the goodness of their non-existent hearts? Unlike the Swiss study that was done with government money, there is no effort to publish the results in any scientific journal where the data and testing methods can be scrutinized.

          • richard

            I guess all the processors, the importing countries and the test results must be wrong….. … Glyphosate is finished….get used to it.

          • Damo

            YAY! A return to atrazine and other dangerous chemicals. Hope you like going back 40 years in the past to a time when the danger was real and not a talking point of tort-loving thugs and unscrupulous businessmen selling snake oil.

          • richard

            You can go back forty years if thats the best you can do….. the rest of us will move forward quite nicely without an obsolete chemical (thirteen weed species on sixty million acres resistant to glyphosate, USDA)

          • Damo

            Don’t know who the rest of us is, but the majority of the world choose glyphosate for a reason. It isn’t the taste.

          • richard

            And now they will have to choose a new drug because glyphosate is finished…. I think its called herbicide stacking which is simply code for toxicity stacking or stacked resistance…. Can you spell desperation?

  • Ted Kuntz

    Clear evidence was available as early as 2009 that formulations that include glyphosate are toxic to human cells at concentrations deemed safe for human consumption. One study has shown that 93% of individuals tested show levels of glyphosate in their urine. Average levels of glyphosate in urine of children in this study eclipsed 3.5 parts per billion. This is highly disconcerting given that another
    study shows glyphosate-related damage to the liver and kidneys of rats
    at levels as low as 0.05 parts per billion.

    The recent court ruling on the carcinogenicity of glyphosate heard evidence that for four decades Monsanto maneuvered to conceal Roundup’s carcinogenicity by capturing regulatory agencies, corrupting public officials, bribing scientists and engaging in scientific fraud. There is no reason t trust Monsanto.

    But its hard to argue with those who put money ahead of health.

    • Joel Peru

      Do you a a source for the study that showed glyphosate-related damage to the liver and kidneys of rats at levels as low as 0.05 parts per billion?

      • Looks like he is talking about this study:

        “Multiomics reveal non-alcoholic fatty liver disease in rats following chronic exposure to an ultra-low dose of Roundup herbicide”

        Here is a report on why this study is flawed:

        To summarise, the study used questionable sample material from aged rats from another flawed study conducted several years earlier, and there statistical analyses was also questionable, resulting in a study with little statistical power.

      • Mike Hatt

        You might find some info from the court documents of the recent landmark court decision in the U.S.. I fall asleep reading court documents, but seriously how do you fight a system that can refute any independent study because they have financial ties? Look into the approval process for aspertame. It’s hilarious, the fda head at the time changed the rules to give his own vote a greater value because they were deadlocked at 2 votes a piece. Result was aspartame approval. Lol!

    • Mike Hatt

      I spent 15 years spraying glyphosate by way of backpack sprayer in a forestry setting. Scientifically illiterate….excuse me, but what experience does this writer have with this pesticide other than writing “opinion ” pieces, bias is quite evident here. It is quite bad, and that’s all I’ll say, because I was censored on for a lengthy post with reference material.

  • richard

    You obviously missed my point…. Clearly a large portion of the public is scientifically illiterate, a large portion of the public is illiterate period…. I was trying to compare the authors contempt of ignorance with the contempt of an intelligent consumer who witnesses a modern western producer consuming NOTHING he grows? That fact is hardly a ringing endorsement of industrial agriculture at its proponents belief in itself…….and its absurd fascination with technology….. Can you spell hypocrisy?

  • ” found evidence this causes problems with the gut at acceptable limits. A new study reveals exactly the same evidence”

    What study is this Sheryl? I asked in a previous thread and you did not answer, but if you are going to make this claim please supply the citation.

  • Mike Hatt

    The enzyme targeted by glyphosate has been found in the gut microbiome of humans. Cornucopia institute 2013.

  • I’m not seeing the link, can you post the title of the study and I will search for it myself.

    “Not saying I’m sure this is 100% the cause, but the evidence is mounting”

    That’s not evidence, that’s just an example of the post hoc ergo propter hoc fallacy. Some people you worked with are sick with undefined illnesses, so you are blaming the thing you dislike, what else were you spraying? whats your diet like? what other work were you doing? Do you exercise? Drug, alcohol or tobacco use? Far too many con-founders to draw any type of conclusion.

    • Denise

      You can find the information yourself but here’s one anyway.…/glyphosate-linked-health-issues-disorders-disease…

      • No kidding Denise, anyone can find information for themselves? You do realise I asked for the reference so I knew the exact study that Sheryl McCumsey was talking about, that way I can assess the same information that she read for myself. I have asked Sheryl to supply the reference several times but she won’t.

        Your link had references to the heavily flawed work of Seralini, I have already posted a link to a report that discusses the flaws in that study, your link also references the even more flawed Swanson study which is nothing more that some nonsense correlations using graphs with altered axes to make the data fit.

        What I am really after Denise is to find out what study Sheryl was talking about when she said:

        “…causes problems with the gut at acceptable limits. A new study reveals exactly the same evidence”

        My guess is that she is referring to the recent Rammazi institute studies, however if she actually read these studies she would find that these studies do not show this. Hopefully Sheryl can provide the reference she is talking about.

    • Denise

      Here’s another.


Stories from our other publications