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Re: shikimic acid accumulation after glyphosate treatment
I understand that the pre harvest use of glyphosate on grains and
oilseeds is a registered application in US and Canada. While driving
across Minnesota and Dakota in late august and early september I
observed the aerial spraying and I was perplexed at that time but later
read about the spraying. Roundup ready crops can be sprayed with other
herbicides to finish the crop.
cheers, Joe cummins
Chrys Ostrander wrote:
Glyphosate is, I assume, "registered" as an herbicide (for crops other
wheat, since wheat is not yet Round-up Ready). Is it also "registered"
pre-harvest treatment or is this an extra-legal use of the chemical?
At 10:15 AM 7/4/03 -0400, you wrote:
In western US and Canada grain and oilseed crops are frequently
treated with glyphosate just prior to harvest that treatment provides
a desiccant effect leading to uniform finishing of the seed. If early
frost is predicted the herbicide acts to mature the seed to avoid
costly frost damage. In wheat the herbicide treatment leads to
accumulation of shikimic acid as is shown in the paper below.
Shiikimic acid is a concern because its accumulation to high levels may
produce wheat that promote cancer or to the production in the wheat
of tannins that are toxic to humans and animals. Cattle and horses that
eat bracken fern rich in shikimic acid suffer high cancer incidence or
toxicity from tannins.
J. Agric. Food Chem., 51 (14), 4004 -4007, 2003. 10.1021/jf0301753
Glyphosate Applied Preharvest Induces Shikimic Acid Accumulation in Hard
Red Spring Wheat (Triticum aestivum)
Gail A. Bresnahan,* Frank A. Manthey, Kirk A. Howatt, and Monisha
Department of Plant Sciences and Department of Cereal and Food Sciences,
North Dakota State University, Fargo, North Dakota 58105
Glyphosate is a nonselective herbicide used as a harvest aid in a
variety of crops. Glyphosate is absorbed into the foliage and
translocated to metabolically active regions in the plant where it
interferes with the shikimic acid pathway. Experiments were conducted to
determine the accumulation and distribution of shikimic acid in wheat
treated with glyphosate at soft and hard dough stages of kernel
development and to determine the fate of shikimic acid during milling
and bread making. Elevated levels of shikimic acid were detected
throughout the wheat plant. Shikimic acid concentrations peaked 3-7 days
after treatment and then declined until harvest. Shikimic acid content
was 3-fold greater in flour and 2-fold greater in the bread derived from
treated wheat than nontreated wheat. Similarly, elevated levels of
shikimic acid were found in the crumbs and crust of bread made with
flour from glyphosate treated wheat. Glyphosate applied preharvest
resulted in shikimic acid accumulation in hard red spring wheat and
subsequent end-use products.
Chrysalis Farm at Tolstoy
Grower of Organic Produce & Botanicals
33495 Mill Canyon Rd.
Davenport, WA 99122
"The purpose of agriculture is not the production of food, but the
perfection of human beings"
Masanobu Fukuoka - "One Straw Revolution"