Fungicide

A bactericide is a type of chemical that kills or inhibits fungi or bacteria. The bactericide can kill or inhibit the growth and reproduction of the pathogen by the virulence of the agent in vitro or in the plant. Some fungicides are not toxic to fungi, but can interfere with fungal pathogenesis or affect the pathogen-host relationship and improve plant defense capabilities. From the end of the 18th century to the 1950s, research on organic fungicides was intensified in search of substitutes for copper and mercury preparations. The most influential factor should be the bactericidal action of the dithiocarbamate derivatives reported by Würsdale et al in 1934. This discovery opened up a new era of organic compounds as fungicides. Following the discovery of the bactericidal activity of thiram, thiram and thiram, in 1935 DuPont discovered the bactericidal activity of the daisen sodium, which was put into production in 1943. After the 1960s, dithiocarbamate fungicides gradually developed into the world's largest class of fungicides. Nearly 300 varieties of organic fungicides have been commercialized so far, and benzenes have dozens of varieties such as pentachloronitrobenzene, hexachlorobenzene and chlorothalonil, and trichloromethane-based fungicides are mainly eliminated. Bacterium and captan. After the 1950s, organic mercury and various fungicides such as terpenoids, organotins, organophosphorus and agricultural antibiotics have been put into practical use. Ethyl thiophanate and thiophanate-methyl developed by Japan's Cao Da Chemical Company in 1969 and 1970 are the two best varieties, especially the latter are widely used in vegetable and fruit trees. In the 1960s, when Japan developed a fungicide for the control of rice sheath blight, it successfully launched organic arsenic fungicides such as Fumeijing and Tianan. It is particularly worth mentioning that a good amount of systemic fungicides have appeared in the heterocyclic fungicides. A breakthrough in the progress of systemic fungicides was actually started in 1960 when Uniroyal discovered the systemic bactericidal activity of rust. In 1966, the rust and oxidized rust were simultaneously commercialized. Later, benomyl, tetramorpholine, thiophanate-methyl, and azine were present. In the 1970s, triazole endoscopic fungicides represented by triazolone were widely recognized. However, the above-mentioned systemic fungicides have a poor effect on many important diseases of oomycetes. In 1977, Ciba-Geigy of Switzerland successfully developed the excellent systemic fungicide metalaxyl for controlling diseases caused by oomycetes. Not only high efficacy, low dosage, but also two-way conductivity, so that the systemic fungicide enters a new stage of widespread use. China is one of the countries that used elements and inorganic chemicals to control plant diseases very early. It has been recorded in many famous works in ancient times (see the history of pesticide development). The most widely used in the 1950s were inorganic fungicides and copper and mercury preparations. Substituted benzenes such as pentachloronitrobenzene have also found applications. Dithiocarbamates and organoarsenic formulations were widely used in the 1960s. In the 1970s, carbendazim was developed and developed into one of the most productive fungicides in China. At the same time, China's agricultural antibiotic Jinggangmycin is also widely used in the prevention and treatment of rice sheath blight. Since the 1980s, such as rice sulphate, ethylphosphorus, such as organophosphorus; triazolone, tricyclazole, and indole in heterocyclic fungicides; thiophanate-methyl, chlorothalonil, and nail cream Many excellent fungicides such as Ling have been promoted and applied.