Last year, tomato yellow leaf curl virus disease broke out in our province, causing many vegetable farmers to suffer heavy losses. So far people have talked about “poisonous†discoloration. Now it is time for the spring tomato planting season, so the prevention and treatment of this disease has become a hot issue of vegetable farmers' advice. Many farmers have yet to understand the degree of knowledge of the yellow leaf curl virus disease. In order to correctly understand this disease and effectively prevent and treat yellow leaf curl virus disease, the main points of this disease identification and control are described below. First, the typical symptoms Yellow leaf curl virus disease is a systemic disease. In the early stage of tomato infestation, the upper leaves first showed yellowing type mosaics. The leaf margin is broad-bright yellow (pictured). The leaf margins are rolled up, become smaller, thicken, and the leaves are stiff. The susceptible plants grew slowly or stagnated, internodes shortened, the plants became dwarfed, the upper part of the stems became thicker, more branches were branched, the leaves became smaller and thicker, the deformed rod-shaped leaves were brittle, the leaves were wrinkled, the upward curled, the growth points Yellowing, the symptoms of the lower old leaves are not obvious. Due to its systemic infection, the symptoms of the upper young leaves are obvious and the lower ones are not obvious. When the disease is severe at the late stage, the plant growth is stagnant and dwarf, and fruit set-up is difficult after flowering. The fruit does not turn normally, resulting in reduced yield or no harvest. Second, the cause of the disease Tomato yellow leaf curl virus has two transmission routes: one is Bemisia tabaci, the other is grafted virus. B. tabaci passer poison. There are more than a dozen biotypes of B. tabaci, of which the B-type B. tabaci is a major mediator for its rapid propagation, strong adaptability, and high efficiency of transmission. Grafting and poisoning. Studies have shown that susceptible scions are grafted onto normal rootstocks, or that normal scions are grafted onto susceptible rootstocks, which can cause whole-system disease. The virus seed and frictional contact are not transmitted, so the outbreak of yellow leaf curl virus disease is closely related to the outbreak of Bemisia tabaci. There were significant differences in the incidence of tomato yellow leaf roll virus disease in different cultivation seasons. The summer-autumn tomatoes sown from May to July were severely affected, and the overwintering tomatoes sown from September to October were less severe. That is, the onset is heavy in the high temperature season and mild in the cold season. In addition to tomatoes, host plants susceptible to infection with yellow leaf curl virus include dozens of species such as mandala, heart-leaf tobacco, tobacco, kidney bean, porteriana, papaya, and many other poisonous plants and tomatoes of different mouths. Overlapping growth seasons allow the virus to multiply and cause cross-infection. Third, treatment methods 1. Use resistant varieties. Selection of disease-resistant varieties, such as: Diffany (powdered fruit), Zidali (red fruit), Dili (red), Feitian, Guanghui, 74-112, Geli, domestic Zheza 301, Suhong 9, etc. Variety. Currently in Hebei, only Zidali, Dilio, Diffany, and 74-11 have demonstrations. Others have not yet entered, so the introduction of species requires careful and formal channels, and it is hoped that the demonstration will be followed by promotion. 2. Strengthen field management. Including fertilizer management, timely pruning and other cultivation measures to promote robust growth of plants. Can also be sprayed Ye Lubao, brassinolide, glutinous calcium, Ruipei green and other nutrients, improve plant resistance to disease. In the pastoral area, the infected plants were found during the period of childbirth and were removed and buried in a timely manner. After the crop is harvested, the straw, deciduous and surrounding weeds are completely removed, keeping the field clean and reducing the source of insects. In greenhouse cultivation, we must also do a good job of smoking and killing insects in the shed to prevent the spread of Bemisia tabaci. 3. Intercropping. According to the feeding habits of B. tabaci, intercropping with some of the more host plants of B. tabaci may reduce the population density of B. tabaci in tomato crops. If tomato and cucumber intercropping are used, the incidence of tomato yellow leaf rolling virus disease can be significantly reduced. 4. Biological control. Insect nets were set up: 60-mesh insect nets were set in the nursery and planting shelters to prevent the infestation of the whitefly. If the temperature in the facility is too high, you can use the 60-mesh insect net only at the lower tuyere, and use the 40-mesh insect-proof mesh at the upper tuyere. Trapping the yellow plate: Using the yellowish habit of Bemisia tabaci, hang a sticky yellow plate in the cultivated field to trap and kill the whitefly. Parasitic parasites: The artificial release of the citron wasp in cultivated fields can effectively control the damage of Bemisia tabaci. 5. Chemical control. B-type Bemisia tabaci resistance is very strong, must adopt comprehensive measures of physical, chemical and biological control, with the emphasis on the early period of growth and development, from the sporadic occurrence of Bemisia pneumoniae spray application. For seedling irrigation, the root canal administration can be controlled by 25% methacrylate dispersible granules or 22.45% alisma microcapsule suspension concentrates. The effective period can be as long as 25 to 30 days. The method is to spray the seedlings 2 to 3 days before transplanting with Aketai 1500 to 2500 times (or a sprayer water plus 6 to 8 grams of medicine) or after using Alika's 10 ml water sprayer to spray the seedlings. In addition to the spray blade, it penetrates into the soil. On average, 2 to 3 kilograms of spray liquid per square meter of nursery bed have a good effect on pest control. The spray application may use 25% Aktai water dispersible granules 2500 to 4000 times solution or 22.45% alisma microcapsule suspension suspension 3000 times solution or 10% imidacloprid wettable powder 1000 times or 2.5% green kungfu agent 1500 times liquid annihilation. The seedling stage can be sprayed with 20% Virus A wettable powder 500 times liquid or 1.5% Phytophthora seedling oil 1000 times liquid. Crepe Machine,Crepe Making Machine,Crepe Cake Machine,Electric Crepe Maker Guangzhou New Power Catering Equipment Manufacturing Co.,Ltd , https://www.gznewpower.com