Herbicide

Any chemical agent that is toxic to some or all plants, particularly those categorized as weeds. Historically a variety of substances have been used including salts, carbon disulfide, borax, pyridine, mercurials, and arsenic trioxide. After 1945 synthetic varieties emerged including: amitrole, picloram, 2,4-D, DDT, atrazine, glyphosate, diquat, and paraquat. Herbicides do not always decompose and have created environmental hazards.