Herbicide development

The beginning of chemical weeding in farmland can be traced back to the end of the 19th century. In the prevention and treatment of European grape downy mildew, it was occasionally found that Bordeaux mixture can damage some cruciferous weeds without harming cereal crops; France, Germany and the United States also found sulfuric acid and sulfuric acid. Herbicidal action of copper, etc., and is used for weeding in wheat and other places. The organic chemical herbicide period began in 1932 with the discovery of the selective herbicide dinitrophenol. The emergence of 2,4-Dt in the 1940s greatly promoted the rapid development of the organic herbicide industry. The glyphosate synthesized in 1971 has the characteristics of wide herbicidal spectrum and no pollution to the environment, and is a major breakthrough of organophosphorus herbicides. Combined with the emergence of a variety of new dosage forms and new use technologies, the herbicidal effect is greatly improved. In 1980, the world's herbicides accounted for 41% of total pesticide sales, surpassing pesticides and ranking first.

Among them are O-isopropyl-N-phenylcarbamate [O-isopropy-N-phe-nylcarbamate, abbreviation IPC: C6H5NHCOOCH-(CH3)2], sodium dinitro-O-cresol (sodium dinitro-O) -cresylate) and so on. The most famous herbicide with auxin is 2,4-D, which is thought to disrupt the hormone balance in plants and make physiological disorders, but it is a very effective herbicide for plants other than grasses. It is generally believed that this selectivity is determined by the magnitude of the detoxification effect of the plant species on 2,4-D, or because the concentration of 2,4-D varies depending on the plant species.