What are the prevention and treatment methods for tomato wilt?

For people who grow tomatoes, they are prone to various diseases, so prevention work needs to be paid special attention. Tomato wilt is the most common disease, especially in the late stage of the disease, it is easy to cause the whole plant to wither and die. Therefore, in order to better grow these crops and increase yields, of course, we must also understand the effective prevention and control methods of tomato wilt.

1. Harmful symptoms

Also known as wilt disease and "plague", it is a soil-borne vascular disease that is difficult to prevent and control, and often occurs concurrently with bacterial wilt. The disease usually occurs during the flowering and fruiting period, and often dies during the peak fruit-bearing period. In the early stage of the disease, the middle and lower leaves of the plant wilt around noon, and can recover in the morning and evening. Later, the wilting symptoms gradually worsen, and the leaves gradually turn yellow from bottom to top and do not fall off until they die. Sometimes the disease only occurs on one side of the plant, while the stems and leaves on the other side grow normally. The base of the stem is water-soaked close to the ground, and pink, white or blue-green mold develops when humidity is high. Pull out the diseased plants and cut open the base of the diseased stems, where you will see that the vascular bundles have turned brown.

2. Causes of disease

1. Fields with continuous cropping, heavy clay and acidic soil, and a large number of wilt pathogens accumulated in the soil.

2. There are a certain amount of underground pests such as nematodes in the soil, and pathogens invade the roots through the wounds caused by the pests.

3. The seeds used for breeding are contaminated with bacteria, the nutrient soil used for breeding seedlings is contaminated with bacteria; or the organic fertilizer is contaminated with bacteria, or the organic fertilizer is not fully decomposed, the dung maggots harm the roots, and the bacteria invade through the wounds and cause harm.

4. Fields with excessive nitrogen fertilizer and insufficient phosphorus and potassium.

5. After continuous rain or heavy rain, the sky suddenly clears up and the temperature rises rapidly; or it is sunny and rainy, and the weather is hot and humid.

3. Prevention and control methods

1. Before transplanting or after harvesting, clear the weeds in the field and around it, and burn or compost them in a centralized manner; deep plow the land to kill stubble and dry the soil to promote the decomposition of diseased and residual plants and reduce the sources of disease and insects.

2. The nutrient soil for seedling cultivation should be sterile soil and should be exposed to the sun for more than three weeks before use.

3. Rotate crops. Severely diseased fields should be rotated with cruciferous vegetables, melons, onions, garlic and other vegetables for 3-5 years. If cucumbers are planted, they must be grafted with black seed pumpkins.

4. Choose disease-resistant varieties and disease-free, coated seeds. If they are not coated, the seeds must be sterilized with a seed dressing or soaking agent.

5. Seedling transplanting, cover with medicated soil after sowing, and spray insecticide and disinfectant once before transplanting. This is the key to disease prevention.

6. Choose fields with convenient drainage and irrigation, dig drainage ditches, lower the groundwater level, and ensure that there is no water accumulation after the rain stops; clean the ditches in time after heavy rain to prevent moisture retention and reduce field humidity. This is an important measure to prevent diseases.