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Use of glyphosate to dry seeds may lead to health problems
(Sunday, July 6, 2003 -- CropChoice news) -- J Cummins:
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 promotes 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 S0021-8561(03)00175-4
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 Chakraborty Department of Plant
Sciences
and Department of Cereal and Food Sciences, North Dakota State
University, Fargo, North Dakota 58105
Abstract:
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. |