Herbicides

Herbicides are chemicals used to kill plants.

Major Herbicide Manufacturers
Herbicides are sold by 3M Company, Agriliance, Amvac, Arvesta, Atochem, Baker, BASF, Bayer CropScience, Cedar, Dow AgroSciences, Drexel, DuPont, Feinchemie, FMC, Ghardat, Gowan, Griffin, Ishihara Sangyo, Lesco, Monsanto, Monterey, Syngenta, Terra, Ube Industries, Uniroyal, United Phosphorus, and Valent.

Pollution of Waterways
According to a 1999 U.S. Geological Survey publication, "Herbicides are the most common type of pesticide found in streams and ground water within agricultural areas. The most common herbicides in agricultural streams were atrazine and its breakdown product deethylatrazin (DEA), metolachlor, cyanazine, alachlor, and EPTC. All 5 of the parent compounds rank in the top 10 in national use." (Since then, cyanazine has been banned in the United States)


 * "One of the most striking results for shallow ground water in agricultural areas, compared with streams, is the low rate of detection for several high-use herbicides other than atrazine. This is probably because these herbicides break down faster in the natural environment compared to atrazine. Studies show that break-down products of metolachlor, alachlor, and cyanazine are much more commonly found in ground water than are the parent compounds."


 * "The herbicides most commonly found in urban streams, in addition to atrazine and metolachlor, are simazine, prometon, 2,4-D, diuron, and tebuthiuron, all of which are commonly used in nonagricultural settings for maintenance of roadsides, commercial areas, lawns, and gardens. Prometon and 2,4-D have among the highest frequencies of urban use. Of the urban herbicides, 2,4-D, simazine, and diuron also have substantial agricultural use, ranking in the top 25 nationally. Diuron and 2,4-D were not detected as frequently as other compounds with similar use, probably because the analytical method for these two compounds is less sensitive and resulted in fewer detections than for other compounds, even when concentrations were similar. As in streams, the most frequently found herbicides in shallow ground water in urban areas were atrazine, DEA, simazine, and prometon. Unlike streams, however, metolachlor was seldom detected, probably because of its lower urban use and lower persistence in the environment compared to the other herbicides."

Classification of Herbicides
Herbicides are classified into the following groupings:
 * Amide Herbicides
 * Anilide Herbicides
 * Arylalanine Herbicides
 * Chloroacetanilide Herbicides
 * Sulfonanilide Herbicides
 * Sulfonamide Herbicides
 * Thioamide Herbicides
 * Aromatic Acid Herbicides
 * Benzoic Acid Herbicides
 * Pyrimidinyloxybenzoic Acid Herbicides
 * Pyrimidinylthiobenzoic Acid Herbicides
 * Phthalic Acid Herbicides
 * Picolinic Acid Herbicides
 * Quinolinecarboxylic Acid Herbicides
 * Arsenical Herbicides
 * Benzoylcyclohexanedione Herbicides
 * Benzofuranyl Alkylsulfonate Herbicides
 * Benzothiazole Herbicides
 * Carbamate Herbicides
 * Carbanilate Herbicides
 * Cyclohexene Oxime Herbicides
 * Cyclopropylisoxazole Herbicides
 * Dicarboximide Herbicides
 * Dinitroaniline Herbicides
 * Dinitrophenol Herbicides
 * Diphenyl Ether Herbicides
 * Nitrophenyl Ether Herbicides
 * Dithiocarbamate Herbicides
 * Halogenated Aliphatic Herbicides
 * Imidazolinone Herbicides
 * Inorganic Herbicides
 * Nitrile Herbicides
 * Organophosphorus Herbicides
 * Oxadiazolone Herbicides
 * Oxazole Herbicides
 * Phenoxy Herbicides
 * Phenoxyacetic Herbicides
 * Phenoxybutyric Herbicides
 * Aryloxyphenoxypropionic Herbicides
 * Phenylenediamine Herbicides
 * Benzoylpyrazole Herbicides
 * Phenylpyrazole Herbicides
 * Pyridazine Herbicides
 * Pyridazine Herbicides
 * Pyridazinone Herbicides
 * Pyridine Herbicides
 * Pyrimidinediamine Herbicides
 * Pyrimidinyloxybenzylamine Herbicides
 * Quaternary Ammonium Herbicides
 * Thiocarbamate Herbicides
 * Thiocarbonate Herbicides
 * Thiourea Herbicides
 * Triazine Herbicides
 * Chlorotriazine Herbicides
 * Fluoroalkyltriazine Herbicides
 * Methylthiotriazine Herbicides
 * Triazinone Herbicides
 * Triazole Herbicides
 * Triazolone Herbicides
 * Triazolopyrimidine Herbicides
 * Uracil Herbicides
 * Urea Herbicides
 * Phenylurea Herbicides
 * Sulfonylurea Herbicides
 * Pyrimidinylsulfonylurea Herbicides
 * Triazinylsulfonylurea Herbicides
 * Thiadiazolylurea Herbicides
 * Unclassified Herbicides

External Resources

 * Common Herbicides, Guide to the most common herbicides including trade names and manufacturers
 * Common Herbicides for Fruit and Vegetable Weed Control, University of Tennessee Extension.

External Articles

 * Different pesticides dominate in different land-use areas, U.S. Geological Survey.