Can tomato virus disease be transmitted? What caused it? Ask an expert to talk about it.

In recent years, tomato yellow leaf curl virus disease has a serious trend in some areas of China. The author introduces the symptoms, causes and prevention suggestions of the disease, hoping that the majority of growers will pay attention to it and avoid serious economic losses. Suggestions on controlling tomato yellow leaf curl virus disease are as follows.

First of all, symptoms

The infected tomato plants were dwarfed, the top leaves turned yellow and became smaller, and the leaf edges rolled up. Early-growing plants are seriously dwarfed and cannot blossom and bear fruit normally. Only the upper leaves and buds showed symptoms later, and the results were small and red, so they could not be eaten.

Second, the cause of disease

Tomato yellow leaf curl virus disease is mainly transmitted by Bemisia tabaci, and it spreads for life after infection. Therefore, Bemisia tabaci is a serious greenhouse, which is easy to cause the occurrence and epidemic of the disease. But Bemisia tabaci eggs do not spread the virus, nor do seeds and mechanical friction spread the virus. In addition, excessive application of nitrogen fertilizer makes plants delicate and poor drainage is more serious.

Third, prevention and control methods

1. Select disease-resistant varieties and cultivate strong seedlings. The earlier the disease harms tomato plants, the higher the incidence rate, so it should be controlled from seedling stage. Select disease-resistant varieties to achieve early prevention and early control. Weeds around the seedbed should be cleaned up, and the soil of the seedbed should be disinfected to reduce the source of the disease.

2. Pay attention to Bemisia tabaci. Attention must be paid to the control of Bemisia tabaci. It can be fumigated with isoprocarb and interspersed with spray; Or choose abamectin, chlorpyrifos, nitenpyram, flonicamid, spirodiclofen, dinotefuran, etc. Spray the whole field every 7- 10 days, and pay attention to drug rotation to avoid drug resistance.

3. Agricultural measures. Properly control the amount of nitrogen fertilizer to keep the field moist. Fertilization and irrigation should be carried out many times, ventilated in time to avoid high temperature in the shed and adjust the temperature and humidity. Increasing the application of organic fertilizer can promote the growth of plants and improve their disease resistance. During the growth period, 806 plant growth liquid can be used to wash or irrigate roots, and gene activator can be sprayed to improve plant immunity. Clear weeds and fallen leaves in the field in time to reduce the source of insects. When tying vines, pruning, forking, dipping flowers and picking fruits, the healthy plants should be treated first, and then the diseased plants should be treated. Pay attention to fully scrub hands and tools with soapy water or trisodium phosphate solution to reduce human transmission.

4. Implement crop rotation. The seriously ill plots should be rotated with crops other than Solanaceae for more than three years. Such as planting cucumbers, beans, grapes and so on. Avoid intercropping and continuous cropping in different stubbles to reduce and avoid the spread of tomato virus disease soil and residues; Poisonous weeds in nurseries and planting sheds should be thoroughly removed to reduce the source of poison; Popularize formula fertilization technology, spray Aiduoshou or plant protection elements to enhance the host's disease resistance.

5. Chemical control. Before tomato seedlings are separated, planted, tied and raked, 0.2%-0.4% potassium dihydrogen phosphate mixed solution or 1: 20-40 times soybean milk or soybean milk powder is sprayed with 1% soapy water to prevent contact infection. Spraying 1 times NS-83 resistance enhancer 100 times before and after planting can enhance tomato disease resistance. At the initial stage of the disease (usually in the 5-6 leaf stage), spray protection was started, and the formula was a bucket of water (15kg)+ 10g urea+12g antaisheng+ningnanmycin 500-fold solution+brassinolide or Aiduo 6000-fold solution, spraying for 4 days 1 time.