Friday, May 10, 2013

Glyphosate Effects

"Claims have been made recently that glyphosate-resistant (GR) crops sometimes have mineral deficiencies and increased plant disease. This review evaluates the literature that is germane to these claims. Our conclusions are: (1) although there is conflicting literature on the effects of glyphosate on mineral nutrition on GR crops, most of the literature indicates that mineral nutrition in GR crops is not affected by either the GR trait or by application of glyphosate; (2) most of the available data support the view that neither the GR transgenes nor glyphosate use in GR crops increases crop disease; and (3) 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."

"Since the herbicide glyphosate (N-(phosphonomethyl)glycine) was commercialized in 1974, it has become the most widely used herbicide in the world, due largely to the wide scale adoption of transgenic, glyphosate-resistant (GR) crops after their introduction in 1996 (Figure (Figure1).1). In GR crops, this relatively high use rate herbicide (commonly 0.5 to 2.0 kg/ha/application) is often used multiple times in a growing season. Use of other herbicides declined steadily, while glyphosate use increased in the three major GR crops (Figure (Figure2).2). The increasing incidence of evolved, GR weeds, as well as weed shifts to naturally glyphosate-tolerant weed species, has resulted in increased use rates and numbers of applications of glyphosate, as well as other herbicides, per growing season in GR crops. Since its introduction, glyphosate has been considered a toxicologically and environmentally safe pesticide, due to its low mammalian toxicity, relatively short environmental half-life, and extremely low activity in soil due to its binding to soil minerals (reviewed by Duke et al.). Furthermore, only green plants, some fungi, and a limited number of microorganisms have the target site, 5-enolpyruvylshikimic acid-3-phosphate synthase (EPSPS), of the herbicide. EPSPS is an enzyme required for synthesis of the essential aromatic amino acids phenylalanine, tyrosine, and tryptophan."

The scientific community is starting to get it.  It looks like they think the system is not corrupted as much as I think it is.  What you read in this article does not explain what I saw with my own eyes last summer and years previous.  There is an unknown Entity causing the GR system to unravel.

They may be right.  If we have good yields this summer with few problems, the system IS NOT as corrupt as I think it is.  That gives us more time to study the problems but also gives more time to ignore the problems of a GR cropping system.

I don't see as many Marestail escapes this spring as I've seen in the past.  Farmers are going back to residuals and more sprays per year to control GR resistant weeds.  About that time though the whole explodes in our face again.  I have seen way too many 20 bushel losses of yield to GR resistant weeds in soybeans.

This article alludes to the problems out there but does not pinpoint what I see going on.

What do you think?

Ed

5 comments:

  1. Thank you for posting something that is counter to your view. As you know I am a supporter of gmo crops and I appreciate the crop and user safety of glylhosate. Gmo crops for us have been a god send. I cant wait for dicamba and 24-d resistant soybeans.

    I'm going to watch our crops closely this summer to try to observe some of the things you've observed in gmo crops. If you are right about a broken system I want to see it with my own eyes. We will see what the season brings. Good luck to you

    David Seck

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  2. A spammer talking about spam, talk about irony. Please disable anonymous commenting, Ed, real users like David would still be able to comment in several different ways.

    Studies based on test plots are great, but real life results are important too, because test plots just don't cover the variety of soils, GM seeds, weather, rain, and farming practices. We need these results too.

    The PDF you linked mentions formaldehyde in passing, but does not even show it in their graph about the degradation path of AMPA, nor the concentration of resulting formaldehyde or its potential toxicity.

    Similarly, the paper mentions that GR plants with one copy of the GR gene are only 50% less sensitive to glyphosate than non-GR plants, and that the newly adapted GR-tolerant weeds obviously don't die, so it's proof that glyphosate does not prevent the absorption of manganese or other minerals. These weeds are not corn or soybeans to be compared with. The other evidences about nutrition presented in the paper seem to be more scientific though.

    The paper also never mentions Round-up, whose surfactant changes the whole compound and makes it even more toxic.

    These are just a few examples of the many unknown facts about GR crops that we are still missing. It doesn't necessarily mean it's bad, just that we don't have the full picture yet. All things considered, the paper seems to be a rather objective summary of 232 other studies and papers, but it addresses only the 3 points mentioned in the abstract, there are dozens of other questions about GR or other GM crops. I think many of the negative effects observed could be partly linked to the predominance of glyphosate and GR crops more than the toxicity of Round-up or problems with genetic engineering. It makes the monoculture situation even worse than it used to be. There is of course much more Round-up in the environment, and it introduces new problems, but there are also less of the more toxic herbicides.

    The paper would be more readable with a table of content too... ;)

    ReplyDelete
  3. I have several good posters who comment under Anonymous, thus I have not cut them off. I hear what you are saying.

    David,

    If this year stays wet and cool, who knows what will happen. Maybe corn yields will actually go up. I don't think so. Just maybe the problem was exacerbated by last year's drought but I don't think so in the long run.

    Those original trait insertions drug in a bunch of bacteria which have mutated in my opinion.

    Watch your crop emerge
    look for deformed plants and seeds
    look for milk leaking out the stalks
    look for premature death of plants
    look for pink leaves which indicate sugars didn't get where they were supposed to

    Ed

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  4. Ed,

    How wet are you now? Looks like you took a good whoopin this week. Guys really moving back to strong rates of 2-4D and residuals for soybeans this spring from what I can tell. Many more really enjoying the benefits of good rates of Banvel/D in the fall. Had 6 tenths last nite and today. We worked all week up to that point.

    Hope you can get something planted soon.

    Phil A.

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  5. Hi Phil,

    Yes it is looking more like 2 years ago every day. We never planted until June 5 that year and had a very good crop so there is hope. I am sure many are looking at preventive planting insurance vs a crop hard again.

    Ed

    ReplyDelete