Glyphosate Weed Control Herbicides

                                                                                     Glyphosate

Glyphosate (IUPAC name: N-(phosphonomethyl)glycine) is a broad-spectrum systemic herbicide and crop desiccant.

It is an organophosphorus compound, specifically a phosphonate,

which acts by inhibiting the plant enzyme 5-enolpyruvylshikimate-3-phosphate synthase.

It is used to kill weeds, especially annual broadleaf weeds and grasses that compete with crops.

Farmers quickly adopted glyphosate for agricultural weed control, especially after Monsanto introduced glyphosate-resistant Roundup Ready

crops, enabling farmers to kill weeds without killing their crops. In 2007, glyphosate was the most used herbicide in the United States' agricultural

sector and the second-most used (after 2,4-D) in home and garden, government and industry, and commercial applications. From the late 1970s

to 2016, there was a 100-fold increase in the frequency and volume of application of glyphosate-based herbicides (GBHs) worldwide, with further

increases expected in the future. This was partly in response to the global emergence and spread of glyphosate-resistant weeds, requiring greater

application to maintain effectiveness. The development of glyphosate resistance in weed species is emerging as a costly problem.

Glyphosate is absorbed through foliage, and minimally through roots, and transported to growing points. It inhibits a plant enzyme involved in the

synthesis of three aromatic amino acids: tyrosine, tryptophan, and phenylalanine. It is therefore effective only on actively growing plants and is not

effective as a pre-emergence herbicide. An increasing number of crops have been genetically engineered to be tolerant of glyphosate (e.g.

Roundup Ready soybean, the first Roundup Ready crop, also created by Monsanto), which allows farmers to use glyphosate as a post-

emergence herbicide against weeds.

While glyphosate and formulations such as Roundup have been approved by regulatory bodies worldwide, concerns about their effects on

humans and the environment persist, and have grown as the global usage of glyphosate increases.  A number of regulatory and scholarly reviews

have evaluated the relative toxicity of glyphosate as an herbicide.