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Mecoprop
Mecoprop (also known as methylchlorophenoxypropionic acid and MCPP) is a common general use herbicide found in many household weed killers and "weed-and-feed" type lawn fertilizers. It is primarily used to control broadleaf weeds.Mecoprop at EXTOXNET It is often used in combination with other chemically related herbicides such as 2,4-D, dicamba, and MCPA, which mimic the plant hormone IAA (auxin) and kill most broadleaf weeds by causing uncontrolled growth. The |
Enantiomer
In chemistry, an enantiomer (Help:IPA/English, /ɪˈnænti.əmər, ɛ-, -oʊ-/ Help:Pronunciation respelling key, ''ih-NAN-tee-ə-mər''), also known as an optical isomer, antipode, or optical antipode, is one of a pair of molecular entities which are mirror images of each other and non-superposable. Enantiomer molecules are like right and left hands: one cannot be superposed onto the other without first being converted to its mirror image. It is solely a relationship of chirality (chemistry), chirality and the permanent three-dimensional relationships among molecules or other chemical structures: no amount of re-orientation of a molecule as a whole or conformational isomerism, conformational change converts one chemical into its enantiomer. Chemical structures with chirality rotate plane-polarized light. A mixture of equal amounts of each enantiomer, a ''racemic mixture'' or a ''racemate'', does not rotate light. Stereoisomers include both enantiomers and diastereomers. Diaste ... [...More Info...] [...Related Items...] OR: [Wikipedia] [Google] [Baidu] |
Phenoxy Herbicides
Phenoxy herbicides (or "phenoxies") 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. Auxins The first group to be discovered act by mimicking the auxin growth hormone indoleacetic acid (IAA). When sprayed on broad-leaf plants they induce rapid, uncontrolled growth ("growing to death"). Thus when applied to monocotyledonous crops such as wheat or maize (corn), they selectively kill broad-leaf weeds, leaving the crops relatively unaffected. File:Indol-3-ylacetic acid.svg, IAA File:2-(4-chloro-2-methylphenoxy)acetic acid 200.svg, MCPA File:2-(2,4-dichlorophenoxy)acetic acid 200.svg, 2,4-D File:2-(2,4,5-trichlorophenoxy)acetic acid 200.svg, 2,4,5-T Introduced in 1946, these herbicides were in widespread use in agriculture by the middle of the 1950s. The best known phenoxy herbicides are (4-chloro-2-methylphenoxy)acetic acid (MCPA), 2,4-dichlorophenoxyacetic aci ... [...More Info...] [...Related Items...] OR: [Wikipedia] [Google] [Baidu] |
Clofibric Acid
Clofibric acid is a biologically active metabolite of the lipid-lowering drugs clofibrate, etofibrate and with the molecular formula C10H11ClO3. It has been found in the environment following use of these drugs, for example in Swiss lakes and the North Sea. Some derivatives of clofibric acid are in a drug class called fibrates In pharmacology, the fibrates are a class of Amphiphile, amphipathic carboxylic acids and esters. They are derivatives of fibric acid (phenoxyisobutyric acid). They are used for a range of metabolism, metabolic disorders, mainly hypercholesterole .... See also * Phenoxy herbicides to which the compound is chemically related References 4-Chlorophenyl compounds 2-Methyl-2-phenoxypropanoic acid derivatives {{Ether-stub ... [...More Info...] [...Related Items...] OR: [Wikipedia] [Google] [Baidu] |
Herbicide
Herbicides (, ), also commonly known as weed killers, are substances used to control undesired plants, also known as weeds.EPA. February 201Pesticides Industry. Sales and Usage 2006 and 2007: Market Estimates. Summary in press releasMain page for EPA reports on pesticide use ihere Selective herbicides control specific weed species while leaving the desired crop relatively unharmed, while non-selective herbicides (sometimes called "total weed killers") kill plants indiscriminately. The combined effects of herbicides, nitrogen fertilizer, and improved cultivars has increased yields (per acre) of major crops by three to six times from 1900 to 2000. In the United States in 2012, about 91% of all herbicide usage, was determined by weight applied, in agriculture. In 2012, world pesticide expenditures totaled nearly US$24.7 billion; herbicides were about 44% of those sales and constituted the biggest portion, followed by insecticides, fungicides, and fumigants. Herbicide is also used ... [...More Info...] [...Related Items...] OR: [Wikipedia] [Google] [Baidu] |
Broadleaf Weeds
Broadleaf weeds are dicotyledonous weeds that may grow in lawns, gardens or yards. They can be easy to spot when growing among grasses. They are tougher than grassy monocot weeds, multiply with ease, and can be very hard to eradicate. Basic characteristics Broadleaf weeds can emerge annually, biennially, or perennially, making consistent management difficult. Perennial weeds are often very difficult to control as the weeds regenerate faster than they can be eradicated. Broadleaf weeds, as their name suggests, often have wide leaves and grow from a stem. Most broadleaf weeds develop clusters of blossoms or single flowers as they mature that can be considered undesirable. The roots of most broadleaf weeds are fibrous in nature. The roots can be thin, a large taproot, or a combination. Many broadleaf weeds spread through their seeds and rhizomes, although some only spread through seeds. Popular broadleaf weeds are chickweed, clover, dandelion, wild geranium, ivy, milkweed, plantai ... [...More Info...] [...Related Items...] OR: [Wikipedia] [Google] [Baidu] |
2,4-D
2,4-Dichlorophenoxyacetic acid is an organic compound with the chemical formula . It is usually referred to by its ISO common name 2,4-D. It is a systemic herbicide that kills most broadleaf weeds by causing uncontrolled growth, but most grasses such as cereals, lawn turf, and grassland are relatively unaffected. 2,4-D is one of the oldest and most widely available herbicides and defoliants in the world, having been commercially available since 1945, and is now produced by many chemical companies since the patent on it has long since expired. It can be found in numerous commercial lawn herbicide mixtures, and is widely used as a weedkiller on cereal crops, pastures, and orchards. Over 1,500 herbicide products contain 2,4-D as an active ingredient. History 2,4-D was first reported in 1944 by Franklin D. Jones at the C. B. Dolge Company in Connecticut. The biological activity of 2,4-D as well as the similar hormone herbicides 2,4,5-T, and MCPA were discovered during World W ... [...More Info...] [...Related Items...] OR: [Wikipedia] [Google] [Baidu] |
Dicamba
Dicamba (3,6-dichloro-2-methoxybenzoic acid) is a selective systemic 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. It has been described as a "widely used, low-cost, environmentally friendly herbicide that does not persist in soils and shows little or no toxicity to wildlife and humans." Despite its success in improving crop yields, dicamba has attracted controversy. According to the United States Environmental Protection Agency (EPA), dicamba's primary ecological risk is for non-target terrestrial plants from exposure through spray drift, whereby dicamba inadvertently migrates to non-targeted neighboring areas, damaging those plants. In 2016, dicamba was approved for use in the United States over GMO dicamba-resistant crops created by Monsanto. Dicamba came under significant scrutiny due to its tendency to sp ... [...More Info...] [...Related Items...] OR: [Wikipedia] [Google] [Baidu] |
MCPA
MCPA (2-methyl-4-chlorophenoxyacetic acid) is a widely used phenoxy herbicide introduced in 1945. It selectively controls broad-leaf weeds in pasture and Cereal, cereal crops. The mode of action of MCPA is as an auxin, which are growth hormones that naturally exist in plants. History In 1936 investigations began at Imperial Chemical Industries, ICIs Jealott's Hill research center into the effects of auxins on plant growth looking specifically for a way to kill weeds without harming crops such as wheat and oats. William Templeman found that when indole-3-acetic acid (IAA), the naturally occurring auxin, was used at high concentrations, it could stop plant growth. In 1940, he published his finding that IAA killed broadleaf plants within a cereal field. Templeman and the ICI group were searching for compounds with similar or greater selective activity than IAA or 1-naphthaleneacetic acid in inhibiting the growth of weeds while not adversely affecting the growth of cereal crops. The ... [...More Info...] [...Related Items...] OR: [Wikipedia] [Google] [Baidu] |
Indole-3-acetic Acid
Indole-3-acetic acid (IAA, 3-IAA) is the most common naturally occurring plant hormone of the auxin class. It is the best known of the auxins, and has been the subject of extensive studies by plant physiologists. IAA is a derivative of indole, containing a carboxymethyl substituent. It is a colorless solid that is soluble in polar organic solvents. Biosynthesis IAA is predominantly produced in cells of the apex ( bud) and very young leaves of a plant. Plants can synthesize IAA by several independent biosynthetic pathways. Four of them start from tryptophan, but there is also a biosynthetic pathway independent of tryptophan. Plants mainly produce IAA from tryptophan through indole-3-pyruvic acid. IAA is also produced from tryptophan through indole-3-acetaldoxime in ''Arabidopsis thaliana''. In rats, IAA is a product of both endogenous and colonic microbial metabolism from dietary tryptophan along with tryptophol. This was first observed in rats infected by '' Trypanosoma br ... [...More Info...] [...Related Items...] OR: [Wikipedia] [Google] [Baidu] |
United States Environmental Protection Agency
The Environmental Protection Agency (EPA) is an independent agency of the United States government tasked with environmental protection matters. President Richard Nixon proposed the establishment of EPA on July 9, 1970; it began operation on December 2, 1970, after Nixon signed an executive order. The order establishing the EPA was ratified by committee hearings in the House and Senate. The agency is led by its administrator, who is appointed by the president and approved by the Senate. The current administrator is Lee Zeldin. The EPA is not a Cabinet department, but the administrator is normally given cabinet rank. The EPA has its headquarters in Washington, D.C. There are regional offices for each of the agency's ten regions, as well as 27 laboratories around the country. The agency conducts environmental assessment, research, and education. It has the responsibility of maintaining and enforcing national standards under a variety of environmental laws, in consultat ... [...More Info...] [...Related Items...] OR: [Wikipedia] [Google] [Baidu] |
Stereoisomer
In stereochemistry, stereoisomerism, or spatial isomerism, is a form of isomerism in which molecules have the same molecular formula and sequence of bonded atoms (constitution), but differ in the three-dimensional orientations of their atoms in space. This contrasts with structural isomers, which share the same molecular formula, but the bond connections or their order differs. By definition, molecules that are stereoisomers of each other represent the same structural isomer. Enantiomers Enantiomers, also known as optical isomers, are two stereoisomers that are related to each other by a reflection: they are mirror images of each other that are non-superposable. Human hands are a macroscopic analog of this. Every stereogenic center in one has the opposite configuration in the other. Two compounds that are enantiomers of each other have the same physical properties, except for the direction in which they rotate polarized light and how they interact with different enantiomers of ... [...More Info...] [...Related Items...] OR: [Wikipedia] [Google] [Baidu] |
