Can pesticide fungicides be divided into several types? What are the characteristics?
There are two ways of action of fungicides: one is a protective fungicide, and the other is a systemic fungicide.
The protective fungicide directly contacts the pathogenic bacteria in vitro or on the surface of the plant, killing or inhibiting the pathogenic bacteria, making it unable to enter the plant, thereby protecting the plant from the pathogen. Such bactericides are called protective bactericides, and their effects are twofold: one is to directly kill the pathogenic bacteria by contact with the pathogenic bacteria after spraying, that is, the "contact bactericidal effect"; the second is to spray the agent on the surface of the plant body, When the pathogenic colony is exposed to the agent on the plant and is poisoned, it is called "residual bactericidal effect".
The systemic fungicide is applied to a certain part of the crop body and can be absorbed by the crop and transported to other parts of the crop body in the body. The fungicide having such properties is called a "systemic fungicide". Systemic insecticides have two modes of conduction: one is apical conduction, that is, after the drug is absorbed into the plant, it is transmitted to the top of the plant with transpiration to the top leaves, buds and leaves, and leaf margins. Most of the current systemic fungicides are of this type. The other is to conduct to the base, that is, the drug is absorbed by the plant body and then transmitted downward along the transport of the photosynthesis product in the phloem.
The principle of bactericides for controlling plant diseases: Simply put, bactericides are compounds that have a toxic effect on pathogenic microorganisms. However, the term "sterilization" is not limited to "killing" the growth of pathogenic microorganisms or the two layers of spore germination. The fungicide capable of killing the pathogenic microorganism can play a bactericidal action, and can inhibit the bactericidal action of the spore germination or growth of the pathogen, and both of the effects can achieve the purpose of preventing disease and treating diseases in agricultural production. The action of fungicides is different, and the methods of use are also different, but fundamentally, the principle of fungicides to control diseases is no more than three, namely chemical protection, chemical treatment and chemical immunity.
