ROUNDUP -- (Good or Bad ??)

UPDATE 2/24/18:  I recently received a critique on the book "Whitewash", a bash piece on GMO's and Glyphosate by Carey Gillam.  The timing and purpose of the book was to educate the public on the cancer causing effects of glyphosate and pressure the EU to not re-register glyphosate for use last fall.  The critique by Karl Haro von Mogal shreds the book and shows how, through the misuse of data,  and using partial truths, the anti-glyphosate crowd is misleading the public for the benefit of the "Organic" movement.  It's a bit difficult to read.  Because of the mirth employed, I had to read it twice to get the straight of the message.  The critique can be read at: < "Whitewash" is hogwash>

    Glyphosate was introduced to the public in 1974 following it's discovery by Monsanto chemist John E Franz in 1970.  Since it's discovery, Glyphosate has been under constant scrutiny with research trying to prove what glyphosate does or does not do.  What we do know is that it has been a very effective herbicide.  We also know that there are some resistant cultivars, and more will become resistant to the effects of glyphosate.  There is no revelation here, all our chemistry has developed resistant cultivars, --it's merely a matter of time.
     Our operation has used a lot of glyphosate and we have been comfortable with knowing that research proved over and over that it is safe for humans and animals.  At times we seem to bathe in the stuff.  We try not to ingest the chemical, but that has probably happened as well.  The first real concern over safety I'm aware of came around 2010, when Purdue professor emeritus, Dr. Don Huber dropped a bomb, stating that Glyphosate and GMO's are harming human, animal and earth's health.  The research that he based his conclusions on has never been duplicated.  With his continual repeating the claim, and the inability to duplicate the results at Purdue and other universities, Purdue disavowed him.  He is the darling of the anti-GMO crowd and continues to lecture world wide on the evils of glyphosate and GMO's.  The next big hit on glyphosate was when the World Health Organization (WHO) through the International Agency for Research on Cancers (IARC) published a statement that glyphosate "probably" is a Group 2a carcinogen.  The label "probably" can be used on a lot of chemistry and preservatives used for growing and processing our food.  Forty three years of research should be able to determine yes or no, --not a "probable".   However, if you want it to be a carcinogen but can't prove it then the next best thing is to damn it with the adverb "probably".   In fact,  Reuters has an investigative arm.  They state that the IARC research conclusions were changed from no evidence of being a carcinogen in the draft version, to a neutral or positive conclusion of being a carcinogen in the final published version.   The < Glyphosate Battle > is an interesting read.   Reuters has been stonewalled by both WHO and the researchers of the IARC on the reasoning for changing their position, --it wasn't apparently the science.   Since WHO's pronouncement, anti-Monsanto/Roundup/GMO activists, using all available media upped the public concern to the point where several countries are considering removing glyphosate from the register of approved herbicides, along with the State of California.
      In the November 2017 edition of No-Till Farmer there is an article on glyphosate titled,  Is Glyphosate Harming Your No-Till Soils?  The article states that the glyphosate molecule is hanging around longer than anticipated.  Glyphosate is negatively effecting some soil microbe communities.  Glyphosate is encouraging some plant diseases.  Glyphosate is interfering with nutrient uptake.  And, glyphosate is effecting mycorrhiza.  Some serious stated findings.
       I have been working with WSU researcher, Tim Paulitz, for several years on glyphosate interaction with soil biota, --principally bacteria and fungi.  Over the years I have gained a lot of respect and confidence in his work and knowledge of glyphosate.  He heads up a lot of glyphosate research and reads journal entries about glyphosate research worldwide.  His own research projects have found no statistical difference in either the bacteria or fungi communities, between ground that has never had glyphosate applied, and ground that has had a lot of glyphosate applied.  He is doing this study over a wide area of the Palouse and is working in three rainfall zones, ---high, medium, low.  I asked him why this study was in conflict with his findings.  His response:
       Tracy, ---- I looked over the No-Till article.  There is nothing new in this article, except the work from Cornell. The rest of the article refers to old work by Robert Kremer. As I mentioned before, he did not have the molecular tools to really address the questions about microbial communities.  He was only working with the small fraction of fungi and bacteria that can be cultured-  less than 1% of what is out there.  Kind of like trying to paint a picture of the world by only looking through a small narrow slit. Rather than trying to rebut his work, I think it is more useful to look at the new work we have done.

        But I will comment on the article from Cornell by Aristilde.  By the way, this article was reviewed by Kremer.  First of all, the No-Till article was misleading in talking about this work, when it said that “beneficial Pseudomonas… decreased when glyphosate seeped into the surface soil layer by leaching or release from glyphosate treated plants”.  In the Cornell paper, they did not work in the soil, or with plants.  All their work was done in the lab in culture. There may have been other work that they did in soil, but I could not find it published.  They took 4 biocontrol strains of the bacterium Pseudomonas and tested them in culture to see how sensitive they were to glyphosate.  Three were relatively insensitive, but one was completely inhibited at 5 mM.  It was also slightly inhibited at 0.5 mM. This is well known- some bacteria have a form of the enzyme that is sensitive to glyphosate, others are insensitive.  Nothing new here. In fact, the original gene that was used in Roundup Ready crops came from a bacterium, Agrobacterium.  But when I converted the molar concentrations into ppm, it came out to 84 ppm and 845 ppm.  Bacteria in the soil environment will never be exposed to these concentrations, unless there is a chemical spill on the soil. So I would say that this study is not really relevant to the real world.  Many things we do in the lab are useful to develop theories and basic understanding, but the key question is, --does this really happen in the real world? If you hit just about any microbe with a high enough concentration of a chemical in culture, growth will be inhibited.  Also remember that bacteria and fungi may behave in culture very differently from in the soil.   In the study they used high tech state of the art metabolomics to show that the shikimic acid pathway and aromatic amino acids were inhibited.  This has been known for 40 years.  These are the target of glyphosate, --an enzyme in the shikimate pathway that plants, bacteria and fungi use to make aromatic amino acids, which are essential.  They also showed you could supply these amino acids to the bacteria and overcome the growth inhibition. Again, this is nothing new.

         Let me address a few other points in the article. The work on Roundup ready soybean and Fusarium was not done with isogenic lines, so the difference could have been inherent differences in the genetic background of the two lines, There is a picture  of petri dishes with bacteria in the article, and says he can tell by looking at them that there are mostly non-beneficials in the glyphosate treatment.  You cannot tell by looking at cultures.  He talks about gene issues, and having transgenic DNA in the soil, --DNA is quickly broken down in the soil, and there is no evidence of these genes being transferred to other bacteria.  He talks about nutrient complications, --again, a non-issue for us since we do not have GMO wheat, --and others from Purdue have rebutted this argument.  The amount of glyphosate in the environment is so small, it does not play a role in chelating nutrients in the soil, which are in much larger concentrations.  He also cites a study on his farm of taking out fescue and then planting soybean, and noted higher levels of fungus on the roots of soybean in the glyphosate take out.  This is classic green bridge effect, and we have known about this risk for 30 years.  

        So, in summary, I think the main risks of glyphosate that our farmers in the PNW have to worry about is the green bridge effect of carrying over root pathogens to a new crop (and we have known this for 30 years) and the risk of developing glyphosate resistant weeds by overuse, --as has happened in the Midwest.  In the end, farmers have to weigh risks with benefits.

        Timothy Paulitz,USDA-ARS,Wheat Health,Genetics and Quality Research Unit,Washington State University, Pullman, WA, Phone- 509 335-7077, 
email: timothy.paulitz@ars.usda.gov

      The Green bridge referenced by Tim P. was discovered and studied by Dr. Jim Cook of WSU.  Root diseases can be carried over from one cultivar to another when planted into a  dying cultivar.  The recommendation is to not plant within 20 days of a Roundup application. Time is part of the recipe for sanitizing a field along with cultivar rotation and cultivar diversity.

HOW DO I SEE THE FUTURE!

         Regardless of  glyphosate or any other chemistry's fate, --they are all under attack, we have to get smarter about raising crops with fewer chemical inputs.  That means we have to learn how to manage cover crops for the purpose of suppressing weed competition and supplying nutrients to our cash crops.  This is a challenge, and the "How-To Book" is just starting to be written for the Inland Pacific Northwest.