"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,2 as well as weed shifts to naturally glyphosate-tolerant weed species,3 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.4). 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
Friday, 10 May 2013
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