How to treat tomato leaf curl disease, how to treat tomato leaf curl disease

1. Physiological leaf curling.

Before and after the tomato harvest, the leaves of the first panicle are slightly curled, or the whole leaf is curled into a cylindrical shape and becomes brittle, which is mainly due to high temperature and drought, and the tomato stomata are closed, resulting in the curling of the leaves. Prevention and control measures: watering and fertilizing in a timely manner after fruit set, and covering with shade nets, covering during the day on sunny days, uncovering at night, and not covering on cloudy days.

2. Deficiency of nutrients.

Phosphorus deficiency is manifested as purple-red on the back of the leaves, small brown dots appear on the leaves, the lower leaves are rolled up, the curled leaves turn yellow, and the tips of the leaves are black-brown and die. It can be solved by applying phosphorus fertilizer to the soil, or foliar spraying of potassium dihydrogen phosphate. Magnesium deficiency is manifested in the first inflorescence fruit expansion stage, the lower part of the gray leaves of the plant lose green, yellowing between the leaf veins, and then expand upwards to form yellow-spotted leaves, and in severe cases, the leaves are stiff or the edges are rolled up, and necrotic spots or brown patches appear between the leaf veins.

Magnesium deficiency can be solved by applying all-element fertilizers or foliar sprays of magnesium sulfate 100 times.

3. Viral diseases are harmful.

Viral diseases are easy to cause tomato plants to roll up leaves, the leaves are curled and clustered, and in severe cases, there are only leaf veins and no mesophyll, and viral diseases are transmitted through contact with poisonous aphids, whiteflies or sap, and high temperature and drought are conducive to its occurrence. Control measures: choose disease-resistant varieties; Implement crop rotation to reduce the source of primary infection; spray potassium permanganate 1000 times liquid at the beginning of the disease; Use 10% net 1500 2000 times liquid to kill poisonous aphids and whiteflies.

Fourth, tea yellow mite is harmful.

Symptoms are narrowing, stiffness, erectness, wrinkling or twisting of the leaves, and finally baldness. The prevention and control agent can be sprayed with 3000 times of afudin.

5. Hormone drug damage.

In the prevention and control of flower and fruit drop with plant hormones, if 2,4-d is accidentally dipped in young leaves or growth points, the leaves or growth points will be bent, the new leaves will not be normal, and the chlorophyll will be twisted and deformed. Prevention and control measures: choose the appropriate concentration when using, generally use the concentration of 15 20 mg kg, and the concentration should be lower when the temperature is high.

When using, pay attention to prevent the liquid from dipping into the young leaves or growth points, and do not spray. After the occurrence of pesticide damage, some growth-promoting nutrient solutions can be applied, such as spraying natural brassin, Aiduo harvest, etc.

If it is the upper volume, it affects the growth, and let him spread it almost once, twice completely.

The prevention and control methods of tomato leaf rolling disease include replenishing water, applying fertilizer, and controlling diseases.

1. Replenish water

Tomato leaf curls are mainly due to lack of water, especially in spring and summer, the plant has a greater demand for water, so it must be watered more to keep the soil slightly moist, so as not to evaporate too quickly, and the leaf surface will dry and curl.

2. Apply fertilizer

Tomatoes need fertilizer during the growth period, especially around the flowering and fruiting period, phosphorus and potassium phosphate fertilizers and potassium dihydrogen phosphate can be applied, if the tomato roots can not absorb nutrients, there will be malnutrition, so that the leaves will wither.

3. Prevention and control of diseases

Tomato leaf curls are mainly caused by viral diseases, after the onset of the disease, bacteria invade the inside of the leaves, so that the leaves are dry and curly, and will fall off when serious.

Tomato planting precautions lead mess

Tomatoes like full sunshine, and light intensity is directly related to tomato yield and quality, so good light conditions must always be maintained in cultivation. Tomato light saturation point is 70,000 lux, generally to ensure the light intensity of 3-10,000 lux or more, in terms of light time, there are 11-13 hours of light every day, the plant growth is the best, and the sunshine can also grow and bear fruit normally when the short locust stall is short.

Tomatoes are temperature-loving vegetables, and generally speaking, they can be adapted to tomato growth in the temperature range of 15 to 35 years. The optimal temperature for the seedling stage is 20 25 during the day and 10 15 at night.

The flowering period is sensitive to temperature, and the optimal temperature is 20 30 during the day and 15 20 at night. The suitable temperature in the fruiting period was 24 26 during the day and 12 17 at night. The optimal temperature for fruit coloring period is 20 25 or more, and the coloring is poor above 30.

1. Temperature control: The temperature is controlled between 15-28 degrees Celsius, and good ventilation is maintained. 2. Reduce fertilization

Apply a thin fertilizer every 20-30 days. 3. Disease prevention and control: disinfect seeds and soil, and spray potassium permenate solution during growth.

4. Watering too much: drain the stagnant water, and water it every 5 days or so in the later stage.

1. Temperature control

Tomato leaf curl disease mostly occurs in the summer of high temperature and humidity, when the temperature is higher than 35 degrees Celsius, the leaves will gradually curl, at this time it is necessary to cool down, maintain good ventilation, and control the growth temperature of tomatoes between 15-28 degrees Celsius.

2. Reduce fertilization

Excessive fertilizer is applied during the growth of tomatoes, leaf curling will also occur, and during the cultivation process, a thin fertilizer can be applied at intervals of 20-30 days, and the fertilizer should be diluted with water, and cannot be sprinkled directly on the roots of tomatoes to avoid burns.

3. Prevention and control of diseases

Tomato leaf curling may be the result of a viral disease, which can damage the stems and leaves of the plant after the onset of the disease, in order to prevent disease, the seeds and soil should be disinfected during the planting process, and the tomato should be sprayed with a solution of potassium high fernate during the growth period.

4. Watering too much

Tomatoes are afraid of waterlogging, too much watering during breeding, will make the root system rot, the leaves gradually curl, at this time to discharge the water, the later can be watered once every 5 days or so, in the rainy season to dig a trench in the field to drain, so that the tomatoes grow normally.

As the temperature rises, especially in summer, the temperature is relatively high, and the pesticide damage will occur if you are not careful when spraying, once the drug concentration is too large, the pesticide damage occurs, the surface of the leaf will change color or have spots, and the leaf will also curl upward.

If the crop uses too much fertilizer, it will lead to an increase in the concentration of soil solution in the root system, which will hinder the absorption of water by the root system, resulting in water shortage in the leaves, causing the leaflets to flip and roll up.

For example, when too much ammonium nitrogen fertilizer is applied in the soil, the midribs of the small leaves on the mature leaves are raised, and the leaflets show an inverted bottom shape, and the leaves appear to turn up and roll. Especially in saline-alkali areas, when the salt concentration of soil solution is high, it is also easier to curl the leaves upward.

When the plant is deficient in calcium and some trace elements, it can cause leaf curling symptoms. These are physiological leaf curls, often distributed on the leaves of the whole plant, not accompanied by the symptoms of bright veins mosaic leaves, often occur on the leaves of the whole plant, it is recommended to use Yanwo chelation in the trace element water-soluble fertilizer, rich in a variety of nutrients, not antagonistic, good absorption, effectively alleviate the physiological diseases caused by the lack of nutrients in vegetables, promote the growth of vegetables, and improve the stress resistance of vegetables.

Vegetable topping is too early, which is easy to breed bacteria in the axillary buds, and the phosphoric acid in the vegetable leaves has nowhere to be transported, resulting in the first aging of the lower leaves and the shrinkage of the leaves.

If the crop is planted too early and pruned too heavily, it will not only affect the development of the underground root system, limit the quantity and quality of the root system, but also make the aboveground part grow poorly, affect the normal growth and development of leaves, and induce leaf curling.

Viral diseases can generally be transmitted by aphids, whiteflies, etc. When the plant has a viral disease, all or part of the leaves will appear from top to bottom and curl upward, and at the same time, the leaves will fade green, become smaller, shrink, clump and other phenomena, and in severe cases, there will only be leaf veins and no mesophyll, which is mostly manifested in the heart leaves and upper leaves.

Using a plant-derived product and spraying it once will cure more than 70%, and it will cure all of it after two or three times.