Diazinon, a colorless to dark brown liquid, is a thiophosphoric acid ester developed in 1952 by Ciba-Geigy, a Swiss chemical company. It is a nonsystemic organophosphate insecticide formerly used to control cockroaches, silverfish, ants, and fleas in residential, non-food buildings. Diazinon was heavily used during the 1970s and early 1980s for general-purpose gardening use and indoor pest control. A bait form was used to control scavenger wasps in the western U.S. Diazinon is used in flea collars for domestic pets in Australia and New Zealand. Residential uses of diazinon were outlawed in the U.S. in 2004 because of human health risks but it is still approved for agricultural uses. An emergency antidote is atropine.
Phenoxy herbicides are two families of chemicals that have been developed as commercially important herbicides, widely used in agriculture. They share the part structure of phenoxyacetic acid.
Glufosinate is a naturally occurring broad-spectrum herbicide produced by several species of Streptomyces soil bacteria. Glufosinate is a non-selective, contact herbicide, with some systemic action. Plants may also metabolize bialaphos, another naturally occurring herbicide, directly into glufosinate. The compound irreversibly inhibits glutamine synthetase, an enzyme necessary for the production of glutamine and for ammonia detoxification, giving it antibacterial, antifungal and herbicidal properties. Application of glufosinate to plants leads to reduced glutamine and elevated ammonia levels in tissues, halting photosynthesis and resulting in plant death.
Protoporphyrinogen oxidase or protox is an enzyme that in humans is encoded by the PPOX gene.
Dicamba is a broad-spectrum herbicide first registered in 1967. Brand names for formulations of this herbicide include Dianat, Banvel, Diablo, Oracle and Vanquish. This chemical compound is a chlorinated derivative of o-anisic acid.
Acibenzolar-S-methyl is the ISO common name for an organic compound that is used as a fungicide. Unusually, it is not directly toxic to fungi but works by inducing systemic acquired resistance, the natural defence system of plants.
Metolachlor is an organic compound that is widely used as an herbicide. It is a derivative of aniline and is a member of the chloroacetanilide family of herbicides. It is highly effective toward grasses.
Dichlorprop is a chlorophenoxy herbicide similar in structure to 2,4-D that is used to kill annual and perennial broadleaf weeds. It is a component of many common weedkillers. About 4 million pounds of dichlorprop are used annually in the United States.
Sulfentrazone is the ISO common name for an organic compound used as a broad-spectrum herbicide. It acts by inhibiting the enzyme protoporphyrinogen oxidase. It was first marketed in the US in 1997 by FMC Corporation with the brand name Authority.
Mesotrione is the ISO common name for an organic compound that is used as a selective herbicide, especially in maize. A synthetic inspired by the natural substance leptospermone, it inhibits the enzyme 4-hydroxyphenylpyruvate dioxygenase (HPPD) and is sold under brand names including Callisto and Tenacity. It was first marketed by Syngenta in 2001.
Acifluorfen is the ISO common name for an organic compound used as an herbicide. It acts by inhibiting the enzyme protoporphyrinogen oxidase which is necessary for chlorophyll synthesis. Soybeans naturally have a high tolerance to acifluorfen and its salts, via metabolic disposal by glutathione S-transferase. It is effective against broadleaf weeds and grasses and is used agriculturally on fields growing soybeans, peanuts, peas, and rice.
4-Hydroxyphenylpyruvate dioxygenase (HPPD) inhibitors are a class of herbicides that prevent growth in plants by blocking 4-Hydroxyphenylpyruvate dioxygenase, an enzyme in plants that breaks down the amino acid tyrosine into molecules that are then used by plants to create other molecules that plants need. This process of breakdown, or catabolism, and making new molecules from the results, or biosynthesis, is something all living things do. HPPD inhibitors were first brought to market in 1980, although their mechanism of action was not understood until the late 1990s. They were originally used primarily in Japan in rice production, but since the late 1990s have been used in Europe and North America for corn, soybeans, and cereals, and since the 2000s have become more important as weeds have become resistant to glyphosate and other herbicides. Genetically modified crops are under development that include resistance to HPPD inhibitors. There is a pharmaceutical drug on the market, nitisinone, that was originally under development as an herbicide as a member of this class, and is used to treat an orphan disease, type I tyrosinemia.
Imazaquin is an imidazolinone herbicide, so named because it contains an imidazolinone core. This organic compound is used to control a broad spectrum of weed species. It is a colorless or white solid, although commercial samples can appear brown or tan.
Bifenox is the ISO common name for an organic compound used as an herbicide. It acts by inhibiting the enzyme protoporphyrinogen oxidase which is necessary for chlorophyll synthesis.
Fomesafen is the ISO common name for an organic compound used as an herbicide. It acts by inhibiting the enzyme protoporphyrinogen oxidase which is necessary for chlorophyll synthesis. Soybeans naturally have a high tolerance to fomesafen, via metabolic disposal by glutathione S-transferase. As a result, soy is the most common crop treated with fomesafen, followed by other beans and a few other crop types. It is not safe for maize/corn or other Poaceae.
Fluazifop is the ISO common name for an organic compound that is used as a selective herbicide. The active ingredient is the 2R enantiomer at its chiral centre and this material is known as fluazifop-P when used in that form. More commonly, it is sold as its butyl ester, fluazifop-P butyl with the brand name Fusilade.
Indaziflam is a preemergent herbicide especially for grass control in tree and bush crops.
Butafenacil is the ISO common name for an organic compound of the pyrimidinedione chemical class used as an herbicide. It acts by inhibiting the enzyme protoporphyrinogen oxidase to control broadleaf and some grass weeds in crops including cereals and canola.
Aclonifen is a diphenyl ether herbicide which has been used in agriculture since the 1980s. Its mode of action has been uncertain, with evidence suggesting it might interfere with carotenoid biosynthesis or inhibit the enzyme protoporphyrinogen oxidase (PPO). Both mechanisms could result in the observed whole-plant effect of bleaching and the compound includes chemical features that are known to result in PPO effects, as seen with acifluorfen, for example. In 2020, further research revealed that aclonifen has a different and novel mode of action, targeting solanesyl diphosphate synthase which would also cause bleaching.
Chlorsulfuron is an ALS inhibitor herbicide, and is a sulfonylurea compound. It was discovered by George Levitt in February 1976 while working at DuPont, which was the patent assignee.
