Antracol Fungicide Trend Report

Fungicide, also known as biocides, bactericidal algaecides, microbicides, etc., generally refer to chemicals that effectively control or kill microorganisms in the water system - bacteria, fungi and algae. Internationally, it is generally a generic term for agents that control various pathogenic microorganisms.

Early fungicides were inorganic compounds, such as sulfur powder and copper formulations (see Bordeaux), which are still in use today. In 1914, I. Rim of Germany first used organic mercury compounds to control wheat smut, marking the beginning of the development of organic fungicides.In 1934, W.H. Tisdale of the United States discovered the bactericidal properties of dimethyldithiocarbamate, and organic fungicides began to develop rapidly thereafter. Developed in the 40s and 50s, there are three main series of organic sulfur fungicides: Fumei, Daisen (such as Daisen zinc) and trichloromethylthiocarbaimide, in addition to organic chlorine, organic mercury, Organic arsenic fungicides have also developed. Most of these fungicides are protective agents and have limitations in application.Since the 1960s, more chemical types of fungicides have emerged, the most important of which is the advent of systemic fungicides.In 1965, Japan developed the organophosphorus bactericide rice blast. In 1966, the United States developed the rust-free spirit. In 1967, the United States developed benomyl. In 1969, Japan developed thiocarbazone. In 1974, the Federal Republic of Germany developed oxazolone, 1975. In the United States, tricyclazole was developed in the United States. In 1977, Mexico developed the metalaxyl. In 1978, France developed aluminum triethylphosphate. The systemic agent represented by the above has become the mainstream of the development of fungicides since the 1970s. At the same time, agricultural antibiotics have also developed rapidly. Organic mercury, organic arsenic and certain organochlorine fungicides are being phased out due to toxicity or environmental pollution problems. A new generation of systemic agents has further expanded the market for fungicides due to improved control effects. By the 1980s, there were more than 200 types of fungicides. According to the survey, worldwide sales of fungicides reached US$2.54 billion in 1985, accounting for 18.4% of total pesticide sales.In 1984, the sales of systemic agents in biocides accounted for 44.2%, and non-endrols accounted for 55.8%. In the past half century, the development of fungicides has mainly focused on the prevention and treatment of fungal diseases, and the research and development of agents for controlling bacteria and viruses has not been sufficiently developed. Since the 1950s, China has mainly developed protective fungicides. Since the 1970s, it has begun to develop systemic fungicides and agricultural antibiotics, and has stopped using organic amalgams. Due to the complicated application technology of fungicides, the development speed is not as fast as that of pesticides. However, the protective effect of fungicides on agricultural production has been increasingly recognized by farmers. With the modernization of Chinese agriculture, the development of fungicides will surely accelerate.

There are many ways to use fungicides, and each method of use is designed according to the law of disease occurrence. The common methods of use are: spraying the crops on the ground, disinfecting the soil and disinfecting the inoculum.For the field crop spraying, the factors affecting the field defense effect of the fungicide are not only the three aspects of the agent, the environment, and the crop, but the application technology of the fungicide is higher than the application technology of the insecticide and the herbicide, especially It is necessary to fully understand the law of the occurrence and development of diseases, because the occurrence and development of diseases are not as clear as pests and grasses.There are two points to note about spraying crops in the field: first, the type and concentration of the agent. The choice of the type of the drug depends on the type of disease, so it is necessary to make a correct diagnosis of the type of disease before it can be prescribed. For example, rice blast can be selected from rice glutinous rice, rice glutinous rice, tricyclazole, wheat powdery mildew, rust, triazolol, triadimefon, etc., and peanut leaf spot should be selected from methyl thiophanate. However, it should also be noted that if the same disease occurs on different crops, sometimes the same agent cannot be used. For example, Bordeaux mixture can prevent downy mildew, but it is easy to cause phytotoxicity to cabbage, so it is not suitable for controlling cabbage downy mildew. After the type of the drug is selected, the appropriate application concentration is selected according to the type of the crop and the growth period, the type of the bactericide, the dosage form, and the environmental conditions.

Application in industrial circulating cooling water1. Quaternary ammonium salt fungicides: dodecyl dimethyl benzyl ammonium chloride, dodecyl dimethyl benzyl ammonium bromide, tetradecyl dimethyl benzyl ammonium chloride, poly season Ammonium salt, etc.2, Chlorine-containing fungicides: chlorine, chlorine dioxide, sodium dichloroisocyanurate (euchlorine), sodium trichloroisocyanurate and so on.3, Peroxide fungicide: hydrogen peroxide, peracetic acid, etc.4, Oxazolines: isothiazolinone, benzisothiazolinone, etc.5, Aldehydes: glutaraldehyde, etc.Application in the waterborne coatings industryOxazolines: isothiazolinone, benzisothiazolinone, etc.

The insecticidal or bactericidal virulence of the agent, commonly referred to as "lethal dose", means that the dose required to kill half (50%) of the biological population (median lethal dose, mg/kg) is often abbreviated as LD50. If the concentration represents a dose, it is "lethal concentration", abbreviated as LC50. The bactericide is expressed as ED50 or EC50, ie the dose or concentration required to inhibit 50% spore germination.Spore germination assayDifferent liquid medicines are sprayed on the surface of the slide or the plate, and the spore suspension is quantitatively added. After the liquid is contacted, the percentage of spore germination is examined by a certain culture time.Inhibition zoneMix the suspension of the spores or hyphae of the pathogen with the agar medium, and after condensing, place a circular filter paper (about 6 mm in diameter) that is sterilized and has different concentrations of the drug solution on the plane of the medium. After the time, due to the diffusion of the drug solution, the growth of the pathogen is inhibited, that is, a "suppression circle" is formed. The size of the suppression ring was measured to compare the virulence of the biocide.Growth rate assayThe drug solution was added to the agar medium, and the bacteria were condensed, and after 24 to 48 hours, the colony growth was observed, and the growth rate was calculated and compared with the growth rate of the control group containing no drug.