Facility vegetable disease chemical control agent type combing

In 2016, China's existing vegetable planting area was 336 million mu, including more than 56 million mu of facilities and vegetables, involving more than 20 kinds of important vegetables such as cucumber, tomato and pepper. Chemical control plays an important role in the prevention and control of vegetable diseases and the sustainable development of the vegetable industry. However, the main pathogens of facility vegetables are becoming more and more serious, which has become an important issue in the chemical control of vegetable diseases, which is related to the service life and market access of fungicides ...

Status of chemical control of vegetable diseases and main types of control agents

Bactericides have an irreplaceable role in ensuring the safe production of crops, but at the same time have an impact on the quality and safety of agricultural products and the ecological environment. Chemical control plays an important role in the prevention and control of vegetable diseases and the sustainable development of the vegetable industry. Chemical prevention and control is developing in a direction of precision, efficiency and environmental friendliness. Some airborne diseases such as downy mildew, late blight, anthracnose, gray mold, leaf mold and powdery mildew mainly rely on chemical control, but the status of chemical control of vegetable diseases is not optimistic, and it does not pay attention to comprehensive prevention and control and relies excessively on chemical control. It greatly increases the risk of resistance to pathogens and excessive pesticide residues. Abuse of abuse is common.

For example, mixing similar drugs; missing the timing of application (seeing the application of the disease to prevent the disease from being effectively controlled, increasing the cost of drug control, increasing the risk of drug resistance caused by pathogenic bacteria); blindly increasing the dosage of the drug caused a large loss of the drug Pesticides in the soil and water environment and vegetables on the residue exceeded; lack of understanding of the characteristics of the drug, not symptomatic application (unreasonable mixed use, carbendazim, thiophanate-methyl to control downy mildew, disease, early blight) Use non-systemic fungicides as systemic agents; use drugs when crops are ill or even heavier; continue to use a large number of drug-resistant agents to control the corresponding vegetable crop diseases; single application means, mainly spray There is no applicator (fine powder machine) and micro-powder "package" suitable for use in high humidity environment and low temperature and illuminating environment; some soil-borne diseases, vascular bundle diseases, systemic infective diseases or disease-transmitting diseases

Vegetable fungicides can be classified into the following types according to whether they have systemic conductivity and the number of active ingredients:

Non-systemic fungicide

Also known as protective fungicides, only used before or at the onset of the disease to prevent the onset. Such as mancozeb, propidium zinc, chlorothalonil, copper hydroxide, basic copper sulfate, copper amide, cyanosin, fluazinam, sulfur, fluke nitrile, fluazinam and the like. It acts by inhibiting spore germination, and the interval of use is generally 7 to 10 days.

2. Systemic fungicide

It can be transported in plants (usually to the apical transport), can be used for spraying or seed treatment, can be transmitted to the new parts of plants after foliar spraying to protect them from pathogens. In addition to its role in preventing pathogenesis, it also inhibits the growth of pathogenic mycelium that has invaded plant tissues, and has a therapeutic effect on the disease that has already occurred. It is often mixed with non-systemic fungicides or processed into a mixture, and the systemic agent. It can improve the level of disease prevention and control.

3. Mixture

The use of mixtures is becoming more and more common, often consisting of a systemic fungicide and a protective biocide, and also consists of two systemic agents. The use of mixed or barrel mixed drugs can achieve the purpose of expanding the sterilization spectrum, increasing efficiency, treating multiple diseases, and delaying the occurrence of pathogenic bacteria resistance. High-risk fungicides are often used in combination with protective fungicides to delay drug resistance.

The fungicides are classified according to the action mechanism as shown in Table 1.

Table 1 Classification of fungicide action mechanism