The occurrence of diseases and insect pests has systematic characteristics, and comprehensive control should be carried out. By analyzing the occurrence characteristics and common types of vegetable diseases and insect pests in greenhouses, appropriate control techniques can be found to improve the cultivation level of greenhouse vegetables.
一、Common pests and diseases of greenhouse vegetables
1. Downy mildew
Downy mildew is also a common disease in greenhouses. Like hot and humid environments, it will threaten many vegetables, such as peppers, cucumbers, tomatoes and other common vegetables, which may be infected. This disease is the most common in greenhouse vegetable cultivation. Diseases vary greatly, depending on the type of vegetables, the symptoms and severity of downy mildew are different.
2. Sclerotium disease
Sclerotinia sclerotiorum is a soil-borne disease caused by fungi. Cucumbers can easily get this disease. In the local greenhouse vegetables, cucumbers account for a large proportion, so sclerotinia disease is very common.
The disease mainly causes damage to fruits, stems, tendrils, etc., usually from the seedling stage to the mature stage, and the damage takes a long time. Sclerotium infection usually leads to spoilage, with watery spots on the infected area, followed by white hyphae.
3. Thrips
Thrips mainly infect eggplants and legumes, and their insect morphology is different in different periods. Thrips are a kind of pest with strong viability. They can be reproduced year-round in the greenhouse, with an average of 15 generations per year. They are extremely harmful to vegetables.
4. Whitefly
There are mainly two kinds of whiteflies, whiteflies and whiteflies. Bemisia tabaci and whitefly will multiply under proper conditions. Whitefly will reduce the photosynthetic efficiency of vegetable leaves and affect the growth level of vegetables.
二、Control measures for greenhouse vegetable diseases and insect pests
1. Agricultural control technology
First of all, choose good varieties. For greenhouse vegetable planting, the characteristics of greenhouse high temperature, high humidity, low light, and large temperature difference between day and night should be considered, and high temperature, high humidity, disease resistant varieties can be selected first. In the scientific selection of seedlings, to verify this seed, select diseases and insect pests that are not sown with healthy seeds, and soil treatment.
At the same time, site preparation and soil disinfection should be done in time. Common pests and diseases should be combined. The mixed disinfectant should be evenly sprinkled on the soil before sowing to kill pathogenic bacteria and pests in the soil. The use of drugs should be used interchangeably, rather than long-term use of a drug to prevent drug resistance.
Strengthen cultivation management, rotate crops regularly, and cannot grow the same vegetable for many years. Once pests are found, all diseased leaves, fruits, plants, etc. must be removed in time to reduce the base of pests. After the last harvest, the greenhouse can be thoroughly cleaned and disinfected in time.
Vegetable fertilization should use organic fertilizer as much as possible to test the soil fertility status. According to the test formula of soil fertility conditions, fertilization can meet the needs of various nutrients in the process of vegetable growth, promote the healthy growth of vegetables, and reduce the occurrence of diseases and insect pests.
2. Physical and biological control technology
Physical control and biological control belong to modern scientific control technology. Compared with traditional drug control, it has little harm to vegetables and the environment, and has no drug residues. It can be vigorously promoted in the process of organic vegetable planting. Some insects have a distinct tendency to certain colors.
Based on this feature, insect sticky boards of a certain specification and color can be hung in the field to trap and kill pests. For example, you can hang yellow sticky insect boards to attract white flies and aphids. Hang blue armyworm trays to lure palm thrips.
In addition, some pests also have obvious phototropism and can be used to attract and kill pests. For example, high-pressure mercury lamps, incandescent lamps, and vibration frequency insecticidal lamps can attract and kill noctuid pests. In addition, high temperature sterilization is also an effective physical control measure.
After the summer vegetables are harvested, the surface of the field can be covered with mulch or greenhouse film. As the temperature in the mulch increases, various soil-borne diseases and insect pests can be completely killed. Biological control technology mainly uses the reproduction of biological pesticides and natural enemies to achieve control effects.
For example, spraying biological agents such as Beauveria bassiana in the greenhouse can effectively control whiteflies and other pests without causing drug residues. It can also release the natural enemies of pests and prey on them, reducing the number of pests at the source.
3. Drug control technology
Pesticide control is a traditional pest control method. In the process of producing pollution-free vegetables, the use of pesticides is not prohibited, but the use of pesticides should be minimized. At present, chemical control is still the most important pest control method, especially in the epidemic and outbreak stage of various pests.
Chemical control technology is not only targeted, but also effective. However, in the specific use of chemical control technologies, the basic principles of "strictness, accuracy, and appropriateness" should always be followed to ensure that pesticide residues meet the requirements of relevant standards.
Specifically, first of all, we must do a good job of monitoring and prevention. On the basis of a comprehensive investigation, the main diseases and pests with specific characteristics and rules are clearly identified, and the occurrence of early damage is controlled as early as possible to ensure "early treatment, less treatment, and timely prevention and control".
Second, a reasonable choice of drugs is needed, that is, when pests and diseases occur due to a certain cause, it is first necessary to clarify whether chemical control measures are required. When necessary, the types of diseases and insect pests should be accurately judged, and the characteristics of pesticides should be mastered in order to achieve suitable drugs on this basis.
In summary, in the process of greenhouse vegetable cultivation, it is necessary to actively strengthen the research on the prevention and control of vegetable diseases and insect pests in the greenhouse. Some farmers do not understand that the prevention and control of vegetable diseases and insect pests are in place, and the excessive use of pesticides leads to drug residues and affects human health. It is necessary to continuously optimize the production technology of supporting vegetables, apply fertilizers scientifically, and use chemical and physical control technologies rationally. Only in this way can we give full play to the role of science and technology and truly improve the yield and quality of pollution-free vegetables.
