CAS 1071-83-6 C3H8NO5P , Glyphosate Herbicide For Crop Desiccation

Description

In 2008, United States Department of Agriculture (USDA) Agricultural Research Service (ARS) scientist Stephen O. Duke and Stephen B. Powles – an Australian weed expert – described glyphosate as a "virtually ideal" herbicide. In 2010 Powles stated: "glyphosate is a one in a 100-year discovery that is as important for reliable global food production as penicillin is for battling disease."

As of April 2017, the Canadian government stated that glyphosate was "the most widely used herbicide in Canada",at which date the product labels were revised to ensure a limit of 20% POEA by weight.[failed verification] Health Canada's Pest Management Regulatory Agency found no risk to humans or the environment at that 20% limit, and that all products registered in Canada at that time were at or below that limit.

Mode of action

Glyphosate interferes with the shikimate pathway, which produces the aromatic amino acids phenylalanine, tyrosine and tryptophan in plants and microorganisms – but does not exist in the genome of animals, including humans. It blocks this pathway by inhibiting the enzyme 5-enolpyruvylshikimate-3-phosphate synthase (EPSPS), which catalyzes the reaction of shikimate-3-phosphate (S3P) and phosphoenolpyruvate to form 5-enolpyruvyl-shikimate-3-phosphate (EPSP).Glyphosate is absorbed through foliage and minimally through roots, meaning that it is only effective on actively growing plants and cannot prevent seeds from germinating.After application, glyphosate is readily transported around the plant to growing roots and leaves and this systemic activity is important for its effectiveness.Inhibiting the enzyme causes shikimate to accumulate in plant tissues and diverts energy and resources away from other processes, eventually killing the plant. While growth stops within hours of application, it takes several days for the leaves to begin turning yellow.Glyphosate may chelate Co2+ which contributes to its mode of action.