Fungicide is used for the prevention and cure of plant diseases caused by different kinds of pathogenic microorganism pesticide, generally refers to fungicides. But in the world, is usually as the floorboard of the medicament for the prevention and control of all kinds of pathogenic microorganisms. With the development of fungicide, and distinguish between kill bacteria agent, kill the virus, kinds and algicide, etc. According to the survey, the world is harmful to the plants of pathogenic microorganisms (fungi, bacteria, rickettsia, mycoplasma, viruses, algae, etc.) there are more than 80000 kinds. Plant diseases caused huge losses to agriculture, the world’s crops reduce output of about 5 trillion kg per year on average. Has repeatedly occurred in the history of the severe famine caused by some kind of plant disease epidemic, even a large number of people starve to death the evil. Use of bactericide is a economic and effective prevention and control of plant diseases.
The role of fungicide way has two kinds: one is the protective fungicide, the other is the systemic fungicide.
First, protective fungicide
Protective fungicide basically has the following categories: sulfur and inorganic sulfur compounds, such as sulfur, suspending agent, solid lime sulfur agent, etc.; Copper agents, mainly bordeaux mixture, copper ammonia mixture, etc.; Organic sulfur compounds, such as TMTD, zineb, generation, ammonium, mancozeb, etc; Phthalic acid and ammonium, such as captan, against bacteria and sterilization Dan Dan, etc.; Antibiotics, such as jinggangmeisu, destroy the blast element, more oxygen and amphotericin, etc.; Other classes, such as leaf blight spirit, bacterial leaf blight net, chlorothalonil, ning heads, etc.
2, action way
In plant body or body direct contact with the pathogen, kill or inhibit pathogenic bacteria, making them unable to enter plant, so as to protect plants from the dangers of pathogenic bacteria. Such fungicide known as protective fungicide, its function has two aspects:
1, contact with pathogens directly kill pathogenic bacteria after spraying, namely “sexual contact antiseptic effect”.
2, sprayed agent on the plant surface, when pathogens falls on a plant in contact with the agent and poison, referred to as the “reasons antiseptic effect”.
Second, systemic fungicide
Systemic fungicide basically has the following categories: benzene and imidazoles, such as benomyl, carbendazim, probenazole, sulfur bacteria spirit and methyl sulfur bacteria spirit, etc. Two formyl amine, such as different bacteria urea, ethylene sclerotium; Organophosphorus, such as rice blast net, net, three different rice blast ethyl phosphonic acid aluminum, etc.; Phenyl amide class, such as armor frost spirit; Sterol biosynthesis inhibitor class, this kind of fungicide including 13 morpholine, ammonia spirit, butyl saite, thioridazine bacteria organism and b bacteria organism, imazalil and mi amide, triazole alcohols and triadimefon, etc., from the point of view of chemical structure, they respectively belonged to morpholine, pyrazole Lin, pyridine, pyrimidine, imidazole, 2, 4 – triazole compounds. Sterol synthesis inhibitors class fungicide with protective and therapeutic effect, has a wide sterilization spectrum.
2, action way
Systemic fungicide used on a certain parts of the object before can be absorbed by crops, and transport to other parts of objects in the body, has the performance of fungicide known as the “systemic fungicide: systemic insecticide. There are two kinds of mode of transmission:
(1) to the top of transduction, namely after the drug is absorbed into plant with transpiration flow at the top of the plant to the parietal lobe, the shoot apex and leaf and leaf margin. At present, a lot of the systemic fungicide category.
Diction is the basic transmission, namely drug absorbed by plants in the phloem after conduction down the transportation of the product of photosynthesis.
The principle of 3, fungicide control of plant diseases
In a nutshell, fungicide is compound of pathogenic microorganisms have poison effect. But the word “sterilization” meaning is not limited to “kill” pathogenic microorganism growth and spore germination two layers of meaning. Can kill pathogenic microorganism bactericide bactericidal effect, can inhibit pathogens spores germination and growth of antiseptic bacteriostasis, both role can achieve the purpose of prevention and cure on agricultural production. Fungicide role in a different way, using methods that vary, but fundamentally, fungicide principle of the prevention and treatment of diseases of three, namely chemical protection, chemical treatment and chemical immunization.