Glyphosate is a broad-spectrum systemic herbicide used to kill weeds, especially perennials. It is typically sprayed and absorbed throught the leaves, injected into the trunk, or applied to the stump of a tree, or broadcast or used in the cut-stump treatment as a foresty herbicide. Initially patented and sold by Monsanto in the 1970s under the tradename Roundup, its U.S. patent expired in 2000. It is now also available in other formulations, its U.S. patent expired in 2000. It is now also available in other formulations, e.g. Resolva 24H, which contains glyphosate and diquat. Glyphosate is the most used herbicide in the USA. In the US, 5-8 million pounds are used annually in US agriculture.
