Classification and function of fungicides commonly used in fruit trees

In the process of fruit tree cultivation and production management, we often use a variety of fungicides when we control all kinds of fruit tree diseases. Understanding and understanding the classification and function of fungicides will be of great help to the selection and use of fungicides for disease control of fruit trees in the future.

Classification of fungicides: fungicides are agents that can inhibit or kill fungi, bacteria, or diseases, which can be divided into:

1. Before the pathogen reaches or invades the host plant, the protective agent is applied to the plant surface to prevent the spore germination or kill the germinating spore, so as to protect the plant from the pathogen. Such as Bordeaux solution, Dyson zinc, bacillus, etc., are generally not water-soluble, can withstand wind and rain erosion and erosion for a long time.

two。 After the disease of the plant, the plant surface is applied to kill the fungi that have entered but most of the bacteria are still growing on the host surface, such as powdery mildew fungicides are often used to control. Eradication agents are often used in the dormant period of crops if the tree used in winter whitening agent or high concentration of stone sulfur mixture to kill overwintering bacteria. Some eradication agents can also be used in agricultural tools and soil disinfection to kill bacteria and nematodes, such as formalin and so on.

3. Internal inhalation fungicides can infiltrate into the tissue through the plant epidermis, and retain or produce metabolites with transport and diffusion in the rest of the plant, in order to protect plants from bacteria or treat diseases, such as verapamil, benzoate, topiramate and so on. This kind of agent is resistant to Rain Water scour and is effective against deep bacteria, but it is also easy to cause resistance to bacteria.

4. Antibiotic fungicides use the metabolites of some fungi to kill or inhibit other fungi. Also known as biological agents, such as distemper, Chunlemycin and so on.

According to the classification of the above fungicides in the process of fruit tree cultivation and management, we should analyze all kinds of diseases on fruit trees and carefully select all kinds of fungicides according to control purpose, disease control time and season. in order to achieve the purpose of chemical control of fruit tree diseases.

Usage of fungicides for fruit trees:

The main results are as follows: 1. The method of plant surface application is called plant surface application. There are five common methods: spray, spray powder, dry white, root irrigation, foam wound, and so on.

2. Medicament treatment of seeds, seedlings, scions, cuttings and other breeding materials, etc., in order to eliminate the bacteria attached to or inside the surface of these materials and ensure that the sowing materials do not bring dangerous diseases.

3. Soil chemical treatment is one of the important measures of chemical protection to apply fungicides or nematodes to eliminate plant pathogens or pathogenic nematodes in soil. This method is mainly used to control fruit tree root diseases or soil-borne vascular bundle diseases, nematode diseases and so on.

Notes on the use of fruit tree fungicides:

Choose the right spraying time

Excessive spraying time will not only cause waste, but also reduce the effect of prevention and control. When using fungicides, the fungicides should be used in time according to the occurrence regularity of different crop diseases and the specific conditions of the diseases. usually, the time of using fungicides should be controlled before or in the early stage of the disease.

Careful mixed use of drugs

Many fungicides are alkaline pesticides, so they can not be mixed with pesticides that are easy to decompose and fail in case of alkaline substances. For example, Bordeaux liquid and stone-sulfur mixture are alkaline and cannot be mixed with dimethoate, 1605, dichlorvos and so on. This all results in the loss of physiological activity or failure of insecticidal ability of insecticidal microorganisms.

Scientific use of pesticides

The spraying times of fungicides are mainly determined according to the residual period and meteorological conditions. Generally every 10 murmurs are sprayed once every 15 days, a total of 2 murmurs are sprayed 3 times. If there is a rainy day after spraying, the spray should be replenished in time. Spray requires fine and uniform fog points, and strive not to leak spray.

Beware of drug damage

In general, drug damage is easy to occur in the flowering stage of seedlings and booting. In addition, it is more likely to cause crop drug damage under the conditions of high temperature and drought, strong sunshine or heavy fog, high humidity and so on.

In addition, the use of fruit tree fungicides, it is necessary to strictly prevent drug damage, such as seedlings and booting flowering stage is easy to produce drug damage, it is best to use fungicides carefully during the period.