E-mail this article to
yourself or a friend.
Enter address:


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


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.