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2-Methyl-4-chlorophenoxyacetic Acid
MCPA (2-methyl-4-chlorophenoxyacetic acid) is a powerful, selective, widely used phenoxy herbicide. The pure compound is a brown-colored powder. MCPA has been extensively used in agriculture to control broad-leaf weeds as a growth regulator primarily in pasture and cereal crops field since 1945. The mode of action of MCPA is as an auxin, which are growth hormones that naturally exist in plants. Overdose application of MCPA acts as an herbicide and results in abnormal growth. History In 1936 investigations began at 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 w ... [...More Info...] [...Related Items...] OR: [Wikipedia] [Google] [Baidu] |
Phenoxy Herbicide
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 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 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:2,4-Dichlorophenoxyacetic acid structure.svg, 2,4-D File:2,4,5-T.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 acid (2,4-D) and 2,4,5-trichlorophenoxyacetic ac ... [...More Info...] [...Related Items...] OR: [Wikipedia] [Google] [Baidu] |
