Huber’s claims in Maui lack evidence

huber150Yesterday, Dr. Don Huber spoke in Maui as part of an event that kicked off a political campaign to ban genetically engineered crops from the island. The same day, a letter to the editor by Dr. Harold Keyser, a retired soil scientist from the University of Hawaii, appeared in the same paper that gave a spotlight to the Huber event.

Due to a time constraint, Huber took about 10 minutes to answer a few questions, so there was not the time for Keyser to ask a question at this event.* Dr. Keyser’s letter to the editor is republished with his permission here.

Poster Child for Anti-GMO Movement Continues to Make Unsubstantiated Claims

By Dr. Harold Keyser

For the past three years, Don Huber, a retired plant pathologist from Purdue University, has been touring the country to promote his sensational claims about a new organism he discovered living in genetically modified (GM) crops, especially those treated with glyphosate (Roundup). This mystery organism supposedly causes severe problems in plant health, animal health and numerous disorders in humans. And now this tour comes to Maui.

It is based on allegations for which data is not provided or available. This is not how science works, and making unsubstantiated claims in public about harm to our health is irresponsible and sad.

Typically a scientist shares their work with other scientists, through presentations at professional meetings or seminars and in scientific publications so that it can be evaluated by peers regarding its accuracy, reproducibility and relevance – science and society have benefited greatly from this process, and, science has a very effective baloney detection kit.

While it is understandable the public is susceptible to being misled on the topics of GMOs by those who believe that opinion is equivalent to evidence-based scientific studies, these particular accusations are in clear conflict with actual evidence from numerous well respected academics in published papers. Just as disconcerting, Dr. Huber has not presented any data or peer reviewed papers to back up his assertions, and has refused to produce samples of the “new organism” to other scientists for further study.

I co-discovered a previously unknown group of symbiotic soybean-rhizobia from China, and once we published our findings in the journal Science I was obliged by accepted scientific protocol to provide these new organisms to any and all requestors so they could verify, falsify or expand on the discovery. Any professional scientist, Dr. Huber included, is obliged to do no less; in science, what is claimed without evidence can be dismissed without evidence.

Further, his claims have been refuted by every peer review of the matter. The academics who have responded include the Journal of Agricultural and Food Chemistry, The Ohio State University Extension Service, Biofortified, the Purdue University Extension Service and the Iowa State University Extension Service. A paper by Dr. Stephen Duke in the Journal of Agricultural and Food Chemistry addresses these allegations head on. The paper states that “neither the glyphosate resistant (GR) transgenes nor glyphosate use in GR crops increases crop disease and that yield data on GR crops do not support the hypotheses that there are substantive mineral nutrition or disease problems that are specific to GR crops.”

Even his own colleagues at Purdue University, his former employer, have challenged Dr. Huber, writing that there is no evidence to support his allegations. In response to these vacuous claims, University of Florida scientist Dr. Kevin Folta has even launched a petition at to demand that Huber either release his study material to the scientific community or stop the misinformation.

In April 2010, the National Research Council of the U.S. National Academy of Sciences issued a report titled, “The Impact of Genetically Engineered Crops on Farm Sustainability in the United States,” which concludes U.S. farmers growing GM crops “… are realizing substantial economic and environmental benefits – such as lower production costs, fewer pest problems, reduced use of pesticides, and better yields – compared with conventional crops.”

GM crops have undergone a rigorous safety assessment following internationally accepted guidelines, and no verifiable cases of harm to human or animal health have occurred. Dr. Huber’s claims are in direct conflict with the weight of scientific evidence supporting the safety and beneficial impacts of GM crops. These reviews and analyses come from our most prestigious scientific bodies and were produced independent of sponsorship by any corporation.  Given the lack of documented safety problems and the proven benefits of GM crops, apparently their most significant risk is not to use them.

An open, fact based exchange of information is essential to discussions about genetic engineering including its benefits and risks. This is not that. The organizations that are responsible for bringing Dr. Huber here to promote imaginary threats are doing a great disservice to the public and to science, and they should simply ask for the evidence.

HaroldKeyser300Harold Keyser, Ph.D. is a retired soil microbiologist, volunteering with Cooperative Extension on Maui to provide education on soil fertility, nitrogen fixation in legumes, and agricultural biotechnology when not volunteering at his son’s nursery. He received degrees in plant science, ecology and soil science from UC Davis, and was a researcher and educator with USDA ARS and the University of Hawaii’s College of Tropical Agriculture and Human Resources.

*An earlier version of this post incorrectly suggested that Dr. Keyser was singled out from the crowd as the reason why he was unable to ask a question. The editors regret the misunderstanding.


  1. Since their advent, billions of people have consumed GMO food with complete safety. If these alarmist could have their way, millions of people in 3rd world nations would starve through anti GMO defacto genocide. In the future, all food will be modified to increase nutrition, prevent disease, lower costs and promote life extension especially needed for peoples in countries that may be affected by global climate change.
    These same people here on Maui killed the Superferry (to save whales) and have driven up the cost of living for everybody through burdensome environmental regulations. They operate in a world of ignorance.

  2. As Kevin Folta has written, when is the good Dr. Huber going to share his findings with the CDC and the FDA? If this is so dangerous, it must be reported !!! If he’s holding back info that can prevent millions from dying, he should be sued to disclose to the CDC and the FDA. Isn’t this criminal negligence?

  3. What if a farmer were to spray a field RR soybeans with glyphosate at rate 3 times higher than normal, let’s say maybe a rate of 96 ounces per acre and he sprayed it not twice but three times during the growing season. Do think that would have any effect on Mn, Fe, Ca, colbalt and iron uptake by the plant or maybe tying up some of the micronutrients within the plant?
    When a farmers sprays glyphosate on RR soybeans late in the season especially when the pods are almost fully developed where does some of the glyphosate go? None of these studies address that possible scenario.
    There is an experiment done in the early 2000’s on what happens when farmers started spraying roundup ready cotton late in this season when cotton balls already formed. So many days after the farmers sprayed the glyphosate the cotton bulbs started falling off the cotton plants and many farmers assumed that the roundup ready gene wasn’t working properly. What actually was going was the glyphosate was starving the plant of essential micronutrients that were necessary for the bulb to stay on the cotton plant. Since glyphosate works systemically it moves to the shoots , roots and to the reproductive parts of the plant. Thus proving that glyphosate can have an effect on nutrient update.

  4. I should make a minor correction to my last comment about RR cotton. The cause of the cotton heads falling off when the cotton was sprayed when it was flowering was do to the fact that the pollen of the RR cotton doesn’t express the RR trait very well so the glyphosate will cause the pollen to die, thus making the head fall off. Here is the link to the website:

  5. Thanks for you questions Paul. I will respond to both messages here.
    The work by Pine and colleagues at NC State shows the effect on flowering structures as a mechanism for sensitivity of late season applied glyphosate on RR cotton, as you noted. The subsequent Bolagrd II/RR flex system apparently does not have that sensitivity. An abstract of the field research on this is found at this website: I looked for the full paper online, and could not find it other than behind the pay wall linked to the abstract site.
    Glyphosate does have the intrinsic ability to bind Mn, Fe, Ca and Co. The degree to which this actually occurs in soil solution would determine any substantial effect on plant uptake. The concentrations of these nutrients are much greater than would be found for glyphosate in soil solutions, meaning that those nutrient concentrations would not be reduced appreciably by glyphosate addition to soil, even at the highest recommended application rates (see the Journal of Agriculture and Food Chemistry link in my article above, pages 3-6).
    Within the plant, the ratio of these minerals to glyphosate would also be very large, making it unlikely that the chelator properties of glyphosate would interfere substantially with plant mineral nutrition (see the Journal of Agriculture and Food Chemistry link above, pages 10-11).
    A very general conclusion is that glyphosate is used at rates well below what would interfere with nutrient availability in soils or plants from binding through chelation.
    I hope this helps.

  6. Why would any sane farmer spray at 3 times the recomended rate? I read your NC State article and will forward it to our local cotton seed supplier.

  7. Some farmers will try anything to kill roundup resistant weeds. I’ve seen more than one farmer spray their soybeans 3 times with glyphosate. I don’t know the rate they were spraying at but I’m sure it was higher than normal. Though there actually was a farmer that I did hear of who did sprayed 96 ounces per acre.

  8. I also wonder if the the EPA or FDA does any random testing on soybeans that have been sprayed with a higher than normal rate of glyphosate when the bean pods are in development phase to see if they exceed the safety requirements for levels of glyphosate, that should be or not be in our food supply?
    After all it’s the EPA’s & FDA’s job insure we have a safe food supply!

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