Anti-GMO groups obsess about superweeds, the non-existent glyphosate-created pest


Read the latest “analysis” on GMOs from Consumer Reports and you’ll “learn” that glyphosate, the chemical developed by Monsanto (its patent is now expired), as Roundup–often but not exclusively paired with herbicide tolerant GM seeds—has led to an “explosion” in what are popularly known as “superweeds.”

The use of genetically modified seeds has … led to about a 10-fold increase in farmers’ use of glyphosate. But that in turn has created a new problem for farmers to battle: a rising number of “superweeds” that have now become immune to glyphosate. “This defeats one of the major reasons why GMOs were introduced in the first place,” says [Michael] Hansen, Ph.D., senior scientist at Consumers Union.

Doug Gurian-Sherman, a activist scientist at the Center for Food Safety, made identical claims when he was a lead scientist at the Union of Concerned Scientists before he was eased out of UCS almost a year ago. Superweeds are a “plague”, he has contended:

It sounds like a bad sci-fi movie or something out of The Twilight Zone. But ‘superweeds’ are real and they’re infesting America’s croplands, Overuse of Monsanto’s ‘Roundup Ready’ seeds and herbicides in our industrial farming system is largely to blame. And if we’re not careful, the industry’s proposed ‘solutions’ could make this epidemic much worse.

Well, Gurian-Sherman and Consumer Reports are over the top wrong.

Let’s start with the use of the term “superweed.” You now see it in stories all the time, even in the mainstream media and in usually reliable sources. But for the most part it’s a meaningless term. Andrew Kniss, associate professor of weed biology & ecology at the University of Wyoming responding to a story in the journal Nature:

I was a little disappointed to see the term “superweeds” in any type of scientific publication. I have repeatedly expressed my displeasure with this term, and my graduate students know better than to ever use the word around me. To see it in a publication as reputable as Nature is exceptionally frustrating.

Many activists use the word to describe a weed that can out compete with other plants, particularly food crops, in ways never seen before on farms. They conjured images out of the Little Shop of Horrors: monstrous, hideous creatures leaving carnage in their wake, as Missouri Farm Bureau head Blake Hurst once wrote. But that’s not the case. In fact, attempts by farmers to stave off bugs, fungus and weeds reach back thousands of years. Hardy weeds that have developed resistance to herbicides, including organic herbicides, have always “plagued” modern farming.

Weeds, just like humans and all living things, have a fierce survival instinct. When a chemical–natural or synthetic–is applied to fields to kill them, random “protective” mutations allow a handful to survive. Over the years, that hardy handful of weeds propagate, and eventually the farmer is faced with a so-called “superweed.” It’s how evolution works.

So let’s dump the scare jargon: superweeds are not ‘super’ in any real sense of the word; they are just weeds that have evolved to evade a particular weed management strategy. If you have ever seen a dandelion so short that it has almost no stem, you’ve seen a superweed. That dandelion’s super power is crouching down, so that lawnmowers can’t get it before it goes to seed. But really, we are talking about weeds that have evolved to withstand applications of our most commonly used herbicides, including glyphosate.

Periodic resistance to pesticides has been growing for about 40 years–in parallel with the rise of large scale farming, both conventional and organic. Contradicting the dire picture painted by Hansen and Gurian-Sherman, there’s been no sudden increase in resistance since genetically modified crops were introduced. In fact, as we’ve reported at Genetic Literacy Project, the level has fallen somewhat since glyphosate resistant crops were introduced. Glyphosate has actually improved the situation with herbicide resistant weeds by decreasing the use of atrazine, which was the most popular herbicide before RR crops came along.

Some weeds have even managed to evolve ways to resist many different herbicides. In an herbicide-free environment, certain weeds will grow faster and bigger, physically crowding out other plants (including desirable crops). They’ll take water and soil nutrients as well as physical space. It doesn’t matter whether the crop is conventional, organic or genetically modified; weeds will act exactly the same way. Resistance comes from using an herbicide that has one mechanism of action—a small number of weeds will be able to survive the herbicide, and return to plague the crops that received the herbicide.

In other words, there is no crisis; weed management is complex; glyphosate is not the devil in plant form. All of which makes the hyperbolic comments spewed by Consumer Reports, once a reliable independent consumer-focused magazine, all the more disappointing. CR is now claiming dozens of weeds now resist glyphosate, which means, it concludes, that the herbicide is “losing its effectiveness.”

While the International Survey of Herbicide Resistant Weeds does count 32 weeds that resist the main action of glyphosate and similarly acting herbicides, the same survey shows there are 150 weeds overall that resist some kind of herbicide. In other words, disease resistance is not a problem unique to glyphosate. It’s relationship to genetic engineering is minimal. And here’s something you won’t read in Consumer Reports: Independent international agencies tracking weed resistance show that it has subsided somewhat since genetically modified crops were introduced. The down trend is modest, so it’s not a reason to stand up and cheer. But the facts belie the hysteria generated by campaigning scientists—let’s call it, in Al Gore’s words, an “inconvenient truth” to hard-edged ideologues.

Instead of promoting fear and perpetuating the myth of Godzilla-like monster plants wreaking havoc on humanity, the Weed Science Society of America recommends a number of practices that any farm (organic, genetically modified, or conventional non-GMO) can take:

• Apply integrated weed management practices, including multiple herbicide modes-of-action with overlapping weed spectrums in rotation, sequences, or mixtures.
• Use the full recommended herbicide rate and proper application timing for the hardest to control weed species.
• Scout fields after herbicide application to ensure control has been achieved. Avoid allowing weeds to reproduce by seed or to proliferate vegetatively.
• Monitor site and clean equipment between sites.

Many farmers are using these practices. But they will never entirely eliminate the damage wrought by weeds, fungi, insects and other pests and the collateral problems that flow from agents used to combat these pests. Let’s not lose sight of the fact that pesticide control is a central component of modern agriculture, whether you run a conventional or organic farm. Crop losses before harvesting average 35 percent worldwide currently. What would those losses be without pesticides? More like 70 percent, say agricultural experts.

Andrew Porterfield is a writer, editor and communications consultant for academic institutions, companies and non-profits in the life sciences. He is based in Camarillo, California. Follow @AMPorterfield on Twitter.

Jon Entine, executive director of the Genetic Literacy Project, is a senior fellow at the World Food Center Institute for Food and Agricultural Literacy, University of California-Davis. Follow @JonEntine on Twitter

  • Benjamin Edge

    It is the patent on Roundup that has expired, not the trademark. Patents are allowed for a maximum of 20 years, whereas trademarks can be renewed indefinitely for 10 year periods.

  • Stuart M.

    Excellent article, I too was so annoyed when anyone spoke about “superweeds.” “Oh No! A superweed! What can we do??? Well, do what you did before there was Glyphosate… plow it under. Oh…okay…

    Couple of typos: …wreaking havoc on humanity…

  • JohnDoe

    Antibiotic use has also led to an explosion of antibiotic resistant bacteria. Within only a few years after the introduction of streptomycin to treat TB, there were strains appearing that were resistant to it. The lesson is that when evolutionary pressure is applied, organisms with beneficial traits survive and see their traits enriched in the local population.

    The same holds for weeds. They could become “superweeds” to natural pesticides too. We simply need to use more integrated and measured approaches when dealing with these emerging threats, be they superweeds or superbugs.

    • Vm

      One reason antibiotics still work is because there are many kinds of antibiotics and we can change around or combine them if resistance develops

      Imagine if there was an anti-antibiotic movement. Fewer young people get into the business. Fewer investors would fund start ups. Government agencies would have more stringent laws for approval, which means more money spent on more tests and red tape i.e. more expensed. The public would buy less antibiotics, i.e. less sales.

      With all the above factors fewer companies would get into the business. That would result in fewer kinds of antibiotics being available.

  • @FarmGirlJen

    Concur. Herbicide resistance is an agronomic issue, not a biotech issue. there are 5 other classes of herbicide resistance more severe than glyphosate and occurred before glyphosate. Stewardship of the technology is important for it to work most effectively.

  • GM Rumsey

    Herbicide resistance is a biotech issue, when 60 million acres in the US have glyphosate resistant weeds to say it isn’t is ridiculous. Also, saying that glyphosate is used sparingly when US department of Agriculture states in 2002/110 million pounds were used and in 2012/283.5 million pounds was used. That’s the last year they have on record, quite convenient there are no new statistics. Last year Texas wanted to use propazine to rid the 3 million acres of cotton of glyphosate resistant weeds. This is a serious problem and adding new crops resistant to new herbicide/pesticide will not change the result. Once again they will become resistant and so more chemicals will be needed.

    • JoeFarmer

      What makes you think that weight of herbicide applied is a remotely useful metric?

    • hyperzombie

      when 60 million acres in the US have glyphosate resistant weeds to say it isn’t is ridiculous

      So, 600 million plus acres have Beyond resistant weeds, almost the entire USA has tillage resistant weeds, along with fire resistant weeds, and there are even hand weeding resistant weeds. And what is wrong with using propazine, better than using cyclizine or paraquat.


    I am pretty sure you mean the patent has now expired. “glyphosate” by itself was never a trademark, and RoundUp is still a live trademark.

    Trademarks, unlike patents, are immortal as long as they are used to denote the source of a product.

    • Good4U

      What you stated is true, however the key element in the regulatory arena, at least in the U.S.A., is not patent protection. The U.S. EPA (wisely) does not concern itself with patents. The key element is the age of the data subsequent to the date of the first registration of the technical substance. Patent law is an entirely separate matter.

  • Vm

    In general its like this

    year -1 = farmer is able to produce food at cost X
    year 0 = herbicide introduced, farmer able to produce food at cost X – Y
    year 50 = herbicide resistance widespread. Farmer able to produce food at cost X again

    Y = the cost needed for other weed control measures
    Why is cost at year 50 still equal to cost at year -1? Because herbicide resistant weeds have the same cost in “other” weed control measures and the same negative effect on crop yield as normal weeds

    What is better, 50 years of low cost crops or 0 years?

    • SageThinker

      To me, it is zero years, if you also factor in “externalities” such as the health costs of the effects of herbicide use. Of course, this must be on a case-by-case basis depending on the herbicide and the health effects, but so must be the calculation regarding the value of “Y” in your equation. I would rewrite your equation as “Total Cost = X – Y + Z” where “Z” is the human health and ecological cost of the herbicide, which is often not well quantified at year zero, as it is not in the interest of the entity selling the herbicide to do so, nor is it in the farmer’s economic interest to do so, generally, but only in terms of conscience, because in our system, the health and ecological costs are generally externalized in economic terms (though not in moral terms as you cannot escape karmic accounting).

      • Vm

        the toxicity to humans and ecological damage vs the benefits of more and cheaper food. Well the benefit of more and cheaper food seems pretty large

        • SageThinker

          That is a good question and one for all of humanity to make together, on many levels. I personally would choose to avoid herbicide use altogether. I also do not buy your claim that herbicide use results in more and cheaper food, as i think that the calculation that you are making is based on the current agribusiness model of food production. I question the whole system of accounting, which is rooted deeply in a worldview that monetizes everything. Smaller-scale farming can provide good living for many people, and many people want that kind of life, and food can be produced as part of a good lifestyle. The world would not go hungry without herbicides, unless the current system of production and distribution along with the inherent inequality among people in terms of wealth and therefore access to food, is maintained strictly, and this is certainly not a requirement for me. I would love to see change in our basic relation to the land and to each other, and not have everything completely determined by a monetary value that ignores so much of reality.

          • Steven Blackthorne

            “Smaller-scale farming can provide good living for many people, and many people want that kind of life, and food can be produced as part of a good lifestyle.”

            The first half of this sentence is pretty astounding. “Smaller-scale farming can provide good living for many people”. I would vigorously dispute this. As in any other industry, economies of scale and mechanization are the keys to making farming both physically tolerable and economically profitable. If small-scale farming could provide a good living, it would be doing so now. As a boy who grew up on a small farm, I can tell you that it is back-breaking, dirty, and very low-paid work. Small farmers go broke, and sell out to larger farmers, who are more efficient for the reasons I just named.

            There still are many small farms in the US, but one key observation about them is that almost all of those farmers have full-time jobs in town. They cannot make a living, much less a good living, from their farms. When I was a boy, in the 60s and 70s, both of my parents had to have full time jobs in town to make ends meet. We were typical in that. Most of the kids I went to school with were from small farm families. In every case, the parents, or at least dad, had a full-time job in town. Those were far less competitive times, on good, fertile soil, with plenty of water, too.

            The only farm kid I knew whose dad made a living from farming, alone, had 1,200 acres of wheat. Now, there’s a crop that will earn you a living. Even there, the capital investments were enormous. One man could farm 1,200 acres by himself because he had a lot of expensive equipment. He could harvest his whole crop in one day with his combine. To justify owning a $250,000 combine, though, you need a big farm.

            The second part of your sentence “many people want that kind of life” makes me chuckle cynically. I have observed that many people do, indeed, romanticize about living on, and running a small farm, but my impression is that it is mostly people who have never done so, and who don’t have a clue what is actually involved.

            Finally, you say “food can be produced as part of a good lifestyle.” It already is. Large, highly mechanized farmers actually have a good lifestyle. They make enough money to live a good life. The romantic picture of a small farm being a good lifestyle is sweetly naive.

          • Vm

            good points

          • JoeFarmer

            “I personally would choose to avoid herbicide use altogether.”

            That’s great if you’re a gardener. But if you’re farming, you have to control weeds somehow. And that means either using herbicides, thermal control (flame weeding) or tillage.

            “Smaller-scale farming can provide good living for many people…”

            Try looking at history, and think about the farm exodus that started circa WWI and continued through the 1960s and even in to the 1970s. People left farms because it was hard work and had little income potential.

            Then do a little pro-forma. How many pounds of veggies would you need to sell to replace your current income? What would it cost you to produce those pounds of veggies? I’ll guarantee you haven’t done that. But let me know what you come up with!

          • SageThinker

            I drive a Fiat tractor. I believe in tillage, judiciously. I also believe in the wheelie hoe and hand weeding. Small scale. Human scale. It works. And there is a great influx of youth who want to farm. It’s been written about. It connects people to the land, and to their food, and what people are lacking is connection. As for spreadsheets on my own agronomy, i’m still alive. I believe that producing healthy food in an ecologically sound way is always good.

          • JoeFarmer

            “I drive a Fiat tractor.”

            And I ride a Moto Guzzi. The difference is I know that Italian motor vehicles are for entertainment, not for getting work done.

            “I also believe in the wheelie hoe and hand weeding.”

            Which proves you don’t farm for a living. Not that I thought you did…

            “And there is a great influx of youth who want to farm.”

            Of course they do, until it gets hard. It wouldn’t be tough to re-code “Guitar Hero” into “Farm Hero” on the PS4.

            “…and what people are lacking is connection.”

            Not around here there’s not. Maybe in Boston where you live in tiny apartments stacked like cord wood and have to take public transit to work in a cubicle. And back again, over and over.

            “I believe that producing healthy food in an ecologically sound way is always good.”

            That’s hardly a revolutionary thought. I’m farming land that’s been in the family for over a century.

          • hyperzombie

            I drive a Fiat tractor.

            Yikes, didn’t they have any REAL tractors?

            I believe in tillage, judiciously.

            Wow, that is so bad for the soil. Save time just dump your soil in the closest river.

            Small scale

            Yep cause small scale everything else works so good.

          • Vm

            smaller scale huh?

            there’s no reason why small scale farmers can use GMO crops with or without “organic” techniques

            “GMO acreage increases globally, especially among small farmers”


      • RJB

        What are the moral terms and karmic accounting for people starving or suffering from malnutrition as a result of policies dictated by wealthy urbanites who are highly insulated from the realities of life of others?

  • Steven Blackthorne

    I enjoyed the article very much, and your main point is well-taken. That is, so-called “superweeds” are super only in one respect, as the term is usually used. That is, they are resistant to glyphosate. They do not have any other special powers. Given that anti-GE activists are generally opposed to the use of Roundup, you would think that they would welcome the emergence of glyphosate tolerance, if it truly did render the herbicide useless.

    A few quibbles and typos:

    1) “Weeds, just like humans and all living things, have a fierce survival instinct.”

    Plants don’t have instincts. This sentence was like fingernails on a blackboard, from a scientific standpoint. Any species responds to evolutionary selective pressure, a better term that you could have employed here, and that you explained without naming it, as such.

    2) “(it’s trademark is now expired)” and “It’s relationship to genetic engineering is minimal.”

    “It’s” should be “Its” here. Someone has already pointed out that it’s the patent, not the trademark, that has expired.

    3) “Instead of promoting fear and perpetuating the myth of Godzilla-like monster plants wrecking havoc oh humanity,,”

    The word “oh” was intended to be “on”, I think. Also, delete the second coma.

    4) “Many activists use the word to describe a weed that can out compete with other plants”

    The term should be hyphenated, IE “out-compete”, and you can delete the word “with” after it, such: “Many activists use the word to describe a weed that can out-compete other plants”.

    • SageThinker

      While we’re at it, there is a double comma in a gasping melodramatic moment, although that may be intentional in the vein of e.e. cummings. “Instead of promoting fear and perpetuating the myth of Godzilla-like monster plants wrecking havoc oh humanity,,the Weed Science Society of America recommends…”

      Oh, you caught that one already, and wrote “delete the second coma” to which i would concur, let’s delete the whole coma altogether.

      • JoeFarmer

        So in addition to your formidable knowledge of physiology, biology and organic chemistry, you keep your Chicago Manual of Style at the ready?

        A renaissance man you are!

  • Fruitwriter

    Since superweeds are only super in that they have evolved to become resistant to one or more herbicides, it is interesting that people who won’t use herbicides, like organic farmers, seem so concerned about them. They haven’t become resistant to a hoe. Herbicide resistance is a concern to those who use herbicides, and they need to use resistance management techniques to protect these tools.

    • Farmer Sue

      Using a hoe? Maybe organic gardener do that, but it’s not earth-friendly nor is it practical. Try that on a farm with real acreage (not a garden).
      Also, hoeing is tilling. Tilling the soil is BAAAAD for the environment.
      And the farmer next door to the organic guy who can’t control his weeds? Those weeds end up in the farmer’s crop. Not very responsible co-existence.

    • hyperzombie

      There are hoe resistant weeds, lots of grasses and thistles, then there are also the biomimics that look like the crop till it is too late.

      • Good4U

        Fruitwriter should try hoeing yellow nutsedge in his little subsistence garden. Can you imagine…every time he hoes one plant he creates dozens, sometimes hundreds, of new ones. After one growing season he would be crying out for an effective herbicide.

        • hyperzombie

          So true, hoeing the crop making more weeds… They are so clueless.

        • JoeFarmer

          Yep, any perennial weed that shoots out rhizomes…

          Or yellow woodsorrel.

          But if you use the classic herbicides to control, you’re a bad guy. Trifluralin (Treflan) or Dual (metolachlor). Hmmm…

      • Dominick Dickerson

        Vavilovian mimicry is so neat. I mean its a pain in the ass for farmers I’m sure, but from a plant science perspective it’s the coolest.

  • Anna

    interestingly, the emergence of weed resistance to glyphosate was declared unlikely according to the patent holders (1991, iirc). kinda makes it hard to be confident in either their “science” or veracity …

    • JoeFarmer

      Show your source or shut up. Glyphosate came on the market in 1974, not 1991, genius.

      Glyphosate was used around the world for 22 years before the first case of resistance showed up – 1996 in Australia, not related to biotech crops.

      So yeah, thanks for nothing.

      • Anna

        I remember the claims; see for example introductory passages (and citation) here:

        • Anna

          here’s Monsanto’s statement to the USDA, 1993 (see page 56):

          • Jackson

            This link is also broken for me.

          • Anna

            try my second attempt at posting the link, posted with the title of the document (it’s a pdf, and will take a bit of time to load)

          • Anna

            here is the search line I used to bring up the document using a google search: Petition for the determination of non-regulated status: Soybeans with a Roundup Ready Gene Monsanto# 93-089U

          • Anna

            I didn’t claim to be Einstein, nor to be a genius, JoeFarmer ^_^ was having a trouble with the paste function ( occasional manifestation of a Mac glitch). So here again is the ncbi link (and the pdf link of Monsanto’s 1993 petition is now working on this computer)

          • Cairenn Day

            Why did part of the Monsanto seed use agreement, detail that farmers needed to plant a ‘refuge’ of non traited plants? Maybe you should stop listening to what other city folks tell you and instead, try listening to the FARMERS who what they are talking about.

          • Anna

            sorry, see:

            in case the link isn’t working (as in previous post), you can search for:Monsanto, Petition for the determination of non-regulated status: Soybeans with a Roundup Ready Gene Monsanto# 93-089U addressed to Mr. Michael A. Lidsky

        • Jackson

          Link is broken.

        • JoeFarmer

          Your link doesn’t work, Einstein.

  • Anna

    (repeated from earlier discussion): link to document stating Monsanto’s claim (1993) that the development of weed resistance was “unlikely” (which seemed implausible at the time, is demonstrably false, and makes their other claims and ‘scientifically backed statements’ seem a wee bit dubious at best)

    • hyperzombie

      Poor Anna, how come you dont complain about Beyond resistant weeds? They both came out at the same time, yet beyond has 125 resistant weeds and Glyphosate only 38?

      • Anna

        actually, my post was not about weed resistance per se, but the claims of Monsanto re: the development of weed resistance.

  • Willard M

    All we need to do is invent more superer poisons and spread them around more and more!

    • Willard M

      Better living through CHEMICALS!

      • RJB

        Better living through being an urban apex consumer who is out of touch with reality and has no problem with telling others how to live their life, but screams like a spoiled child when they are told they need to change!

        • Willard M

          ‘urban apex consumer.’ How do you know things about me? Or are you just ASSuming?