The use of pesticides is the same as that of drugs. First use natural substances, then extract effective components, and then make chemical preparations.
Weeds and aconite are both insect repellent pesticides in ancient Chinese books. Mangrove is an evergreen shrub, which is produced in the middle and lower reaches of the Yangtze River in China, and its fruit is highly toxic. Aconitum carmichaeli is the lateral root of Aconitum carmichaeli, which is poisonous. Aconitum is a perennial herb with tuberous roots, which contains alkaloids-aconitine, which is very toxic. In ancient China, hunters used its juice to paint arrows to kill animals. It was also used in war. Artemisia argyi is still widely used in rural areas of China.
Poisonous plants such as tobacco, pyrethrum and derris are widely used as pesticides all over the world. Pyrethrin and rotenone are substances extracted from pyrethrum and rotenone.
Arsenic (As2O3), realgar (AsS) and orpiment (As2S3), natural minerals containing sulfur and arsenic, and natural sulfur are commonly used as insect repellent, insecticide and rodenticide all over the world.
1858, carbon disulfide (CS2) was first used as a chemical substance to control grape aphids in Europe. Then potato beetles were rampant in the United States, and 1860 was controlled with Paris green. The chemical name of Paris polyphylla green is copper arsenite acetate [(Ch3coo) 2cu 3cu (ASO 2) 2], which is a kind of dark green powder, and can control many pests of fruit trees and vegetables except potato beetles.
In 1882, copper sulfate is used for sterilization. Inadvertently opened a glorious page in the history of fungicides, which is Bordeaux mixture. Bordeaux is a small town on the Atlantic coast of France. It was originally unknown, but it was famous for an accident. A vineyard owner in this place sprayed a mixture of copper sulfate and lime water on the grapes on the roadside to prevent passers-by from picking them casually. Grape downy mildew occurred in 1878. The owner found that the place sprayed with this mixture was not harmed by downy mildew, and the grapes were harvested. After the research of French plant physiologists, it is proved that this mixture has the effect of preventing and treating many plant diseases, and it soon became popular all over the world, and it is called Bordeaux mixture.
Organic synthetic pesticides appeared in the 1920s. Since then, pesticides have been produced on a large scale and become a production department of the chemical industry. Organochlorine pesticides were first used, among which DDT and HCH were widely used.
1874 O. Tseidler, a German chemistry doctoral student, described the synthesis of dichlorodiphenyltrichloroethane in his paper, but did not talk about its insecticidal effect. Later, this compound was also called 223 for short. Because two is di and three is tri in English, it is also called DDT. We are transliterated from DDT, and we have a little image when spraying. More than 60 years later, Miller (P.H.Müller, 1899 ~ 1965), a chemist of J.R.Geigy Company in Basel, Switzerland, made it again and found its insecticidal effect. 1942, the company started mass production. 1944, a large-scale typhus occurred in Naples, Italy. After a few days of extensive spraying DDT, typhus was controlled. 1945 aerial photography in the south Pacific killed mosquitoes, and local malaria was controlled. According to the statistics of FAO, during the period of 1948 ~ 1970, 50 million people were saved from malaria. DDT is widely used to kill leaf roller moth, red bollworm, mosquito, fly, bug, cockroach and so on. Miller therefore won the 1948 Nobel Prize in Physiology and Medicine.
HCH was first made in 1945 by R. E. Slade, a chemist of Imperial Chemical Industry Company. It is made by introducing chlorine into benzene under the irradiation of sunlight or fluorescent lamp. It is named hexachloride because its molecule contains six chlorine atoms, six carbon atoms and six hydrogen atoms. 1946 started mass production. It is as effective as DDT in killing pests, especially in controlling agricultural pests such as locusts, rice borers and wheat midges, and sanitary pests such as mosquitoes, flies and bedbugs.
DDT and BHC are simple to manufacture and have good insecticidal effect, but after long-term use, they will remain in soil and crops for a long time and are not easy to decompose, resulting in a large amount of accumulation in human and livestock, which is seriously harmful to human health. Therefore, after a period of popularity, many countries announced the ban from 197 1 one after another, and China also stopped production and use from 1983.
Shortly after organochlorine pesticides appeared, organophosphorus pesticides appeared, which immediately filled the pesticide gap after organochlorine pesticides were banned. Organophosphorus pesticides are not nontoxic. But most of them will not remain in the environment and organisms for a long time, and can be decomposed into non-toxic water-soluble substances and excreted.
Organophosphorus pesticides began to be developed in Germany after World War I, including Tabeng made by 1932 and Sarin made by 1937. Because it is too toxic, it is not used as a pesticide. 1On March 20th, 995, a poisonous gas incident occurred in Tokyo subway in Japan, that is, sarin was released, which is a highly toxic organophosphorus poison that destroys the nervous system. This incident poisoned more than 5000 people and killed 12 people, which shocked the world.
G. German agricultural chemist Schrade participated in the above research and development. He developed more than 300 kinds of drugs, and after screening, he adopted some of them. TEPP (Tetraethyl Pyrophosphate) discovered in 1938 was first used. Parathion was found in 1944, also known as 1 605, and named diethyl (p-nitrophenyl) thiophosphate vinegar.
1950 melamine chemical company in the United States found that malathion, a low-toxic pesticide, became the most important pesticide, and various organophosphorus pesticides were developed by major companies in Germany, Switzerland and Japan. Malathion is also known as Malaxilong, Marathon, etc. The scientific name is diethyl [(dimethoxy phosphothio) thio] dibutyl ester.
Then trichlorfon developed from 1952 to 1954 and dimethoate from 1956. Dimethoate is the first pesticide with low toxicity to mammals. 1965 monocrotophos was successfully developed. Up to now, more than 100 kinds of organophosphorus pesticides have been used in the world, and hundreds of them have been screened out, and new varieties are still emerging.
Before the 1940s, the earliest rodenticides were brucine, red onion, yellow phosphorus, zinc phosphide (Zn3P2), thallium sulfate (Tl2SO4), barium carbonate (BaCO3) and so on. After the 1940s, ANTU was also called thiourea, 1 080, and its scientific name was sodium fluoroacetate.
Herbicide is a kind of medicine to remove weeds in the field. This is a difficult and skillful job, because these chemicals must remove weeds without harming crops, and weeds and crops are plants. At first, some inorganic compounds were used, such as copper sulfate and ferric sulfate. At present, most of them are complex organic compounds, such as chlorpyrifos and herbicide diethyl ether. Their products have also rapidly developed to hundreds.
Defoliation agent is a herbicide used to defoliate cotton before harvesting, which is convenient for mechanized harvesting. Spraying cotton before harvest will make the leaves fall off quickly, so mechanical harvesting is more convenient and effective.
Plant growth regulators can stimulate the growth of plant cuttings and their roots. The most commonly used are 2,4-drops (or 2,4-drops) and naphthylacetic acid.
In order to improve the efficiency of agricultural production and solve the growing food demand in the world, pesticides are developing with each passing day.