As early as 1932, Lange and Krueger discovered the role of Organic Phosphorus compounds in crop protection and carried out extensive research work at the end of the 19th and early 20th centuries. They synthesized in 1944 codified as E605 compounds, Organic Phosphorus compounds in the use of a major breakthrough, because many of the subsequent compounds are from the compound for the structure of the mother slightly modified. Subsequently, Organic Phosphorus compounds with its broad-spectrum, highly efficient insecticidal activity, easy to use, easy to degrade under natural conditions, etc., become the main force in the pesticide, the number of varieties and production capacity to occupy the first long. Not just pesticides, Organic Phosphorus compounds are still fungicides, herbicides and plant growth regulators and other pesticide fields also have a great market.
However, Organic Phosphorus pesticides due to long-term use caused by a large number of pests to its resistance, but also in the production and use of unsafe, its toxicity and residue is also high. Therefore, some countries have adopted some of these highly toxic varieties of banned and restricted use or elimination of measures, such as the US Environmental Protection Agency has plans to re-examine its toxic organic phosphorus varieties a total of 23. There are also a number of varieties produced and used in our country, as in Table 6-2 underlined for the United States to re-examine varieties.
However, China is a large resource of phosphorus, in the adjustment of pesticide varieties how to make full use of resources, but also placed in front of us a problem. China now also has a certain percentage of pesticide plants in the production of organic phosphorus pesticides, in terms of equipment and equipment there is a basis. Therefore, the most economical way is to China's organic phosphorus toxic products to replace, to develop more efficient, low toxicity of organic phosphorus varieties. For the development of national conditions and pesticides, we should produce some of China's organic phosphorus pesticide varieties, especially foreign registration in China, but the patent or protection period has not yet expired products are often efficient, safe, and good environmental compatibility Characteristics, for the replacement of methamidophos and other insecticides have important significance.
According to the chemical structure of organic phosphorus insecticide can be divided into: phosphate, phosphorothioate, dithiophosphate, pyrophosphate, phosphonates, phosphoramides and so on. The first three varieties of organic phosphorus insecticide occupies an important position.