Archive for July, 2015

The Evils of Roundup?

The last couple of months have been pretty busy for this Plant Doctor. As I begin to get the almonds ready for harvest by cleaning up the weeds on the orchard floors, I look back at all the herbicide recommendations I’ve made over the years and wonder about all the questions that come up about “the evil Roundup”. Yes, I recommend a lot of it. Out of the 8000 acres I take care of probably over half get at least one application, and only 140 of those acres is GMO Roundup Ready. What is it that everyone is so up in arms about?

Roundup

Roundup (glyphosate) is “toxic” and causes cancer: I have read many studies and many discussions about studies that claim to show that glyphosate causes cancer. I have yet to find a study that hasn’t been disproved by a number of researchers and scientists. The one study many people seem to point to regarding Roundup and cancer is the one done on rats by Seralini. You can find plenty of information on how bad that study was. None of that information can be taken seriously. A long discussion on the topic of Roundup and cancer can be viewed on Reddit as well. There are plenty of other “studies” that people seem to find but I’ve yet to see one that hasn’t been picked apart through scientific reviews. Studies showing links to glyphosate causing autism and being found in breast milk have also been busted. Following the science is a bit tedious and time consuming and I can’t say I’ve looking into everything but the studies I have looked at touting adverse health effects of glyphosate don’t seem to lead to anything credible.

Now it is true that the International Agency for Research on Cancer, an arm of the World Health Organization, issued a report that classified glyphosate as a “probable” cause of cancer. Micheal Specter’s article on Roundup and Risk Assessment in the New York Times points out that “ ‘Probable’ means that there was enough evidence to say it is more than possible, but not enough evidence to say it is a carcinogen..” The dictionary definition of probable is “supported by evidence strong enough to establish presumption but not proof”. Proof is something that is lacking in the link between glyphosate and cancer. Many studies have been done and no connection has been found. There are many things on the IRAC list of probable carcinogens. Glyphosate has many benefits and without any real proof of harm there is no credible reason not to use it.

GMO FARMING

Roundup is overused in GMO crops and is producing “super weeds”: Weeds that are resistant to herbicide are not unique to glyphosate. Resistance management drives many decisions on pesticide use. I advise the farmers I work with to only have one herbicide resistant crop and do not plant that back to back in the same field. Roundup is not the only herbicide I use and most of the time when I use it, it is in combination with another product since combinations slow down the development of herbicide resistance. I certainly won’t refute that there are weeds resistant to glyphosate. But there are weeds resistant to other herbicides as well so it isn’t “Roundup” but it is the way people use it that causes the problems.

Roundup is killing the soil: There was an article in the NY Times about soil degradation and glyphosate use. Looking at the article and the actual study (if you can call it that) there are so many variables that were not taken into account that you can hardly attribute the effects just to the glyphosate use. The fact that glyphosate is widely used and that these effects are not widely reported makes me think the claim is not justified. But I am open to the possibility that further research may uncover some issues in the future. If that happens, adjustments will be made to incorporate the new information into our decisions. New information is always welcome. The farmers I work with have not seen any adverse affects of glyphosate use. Most of the production problems we deal with can be clearly identified as to causes (that doesn’t mean fixing them is all that easy).

bees-gmos

Roundup is killing the bees: The study that is commonly cited uses a methodology that really doesn’t fit real world conditions.  In this study bees were fed a sugar solution laced with levels of glyphosate expected to be found after a typical field application. Hardly real world conditions. The EPA has done many studies and have found no toxic effects on bees. In a post at ScientficBeeKeeping.com there is a quote with references that states “there is no strong evidence that the spraying of Roundup or generic glyphosate herbicide is directly causing significant bee mortality.  However, Drs. Jim and Maryann Frazier have legitimate concerns about the effect of some adjuvants—especially the organosilicones [27], [28]. ” Glyphosate is rarely sprayed on flowering crops and the majority of the time you are spraying it on small weeds before they bloom so it isn’t likely bees would be picking up much glyphosate in pollen, even at field applied levels. Probably the biggest problem with glyphosate and bees is more of an issue of it working so well that now there are no weeds for them to supplement their nutrition. The Scientific Bee Keeping post touches on that as well. But European honeybee colonies used to pollinate crops are actually starting to increase which suggests that the increased use of glyphosate is not damaging their populations. Those that would like to find some kind of link to glyphosate and bee decline have now pointed to wild bumblebee decline and the lack of weeds these species have to forage on. But new research suggests that climate change may be the issue of declining bumblebee populations.

I’m sure there will still be many people who don’t like “Roundup”, Monsanto or GMOs. The sure volume of false information and poor science that is out there for those that want to ingest it pretty much ensures a steady diet for those who have their minds made up. As for me, I have crops to care for and farmers that need to produce those crops to earn a living and feed a growing population. Glyphosate is an inexpensive, effective tool so lacking any good scientific reason not to continue using it, I’ll continue to recommend it where it is needed, when it is needed and in line with good Pest Management practices.

Do you have a question about crop protection practices or a topic you would like me to explore? Leave me a comment or, if you are on Facebook, you can post a question on the public group Pesticide Myth Busters and let the community there help you find a answer.

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