What symptom does tomato (tomato) roll leaf disease have? What kind of medicine should I take? How to prevent and cure?

Whether greenhouse tomatoes or open-field tomatoes, especially in high temperature and drought environment, leaf curling phenomena with different symptoms are easy to occur. What are the symptoms of tomato leaf roll disease? What kind of medicine should I take? How to prevent and cure?

With regard to tomato leaf curling, it can be divided into upward curling leaf and downward curling leaf. No matter the tomato leaf curls up or down, it is a physiological disease. The main reasons are as follows:

The reason for curling leaves on tomatoes:

First, after entering the peak fruiting period, tomatoes encountered high temperature and dry weather and could not replenish water in time, at this time, the leaf area was large, high temperature and strong light enhanced leaf transpiration, and the lower leaves of the plant were easy to curl up. Especially in the vents, tomato curls tend to be heavier.

Second, the summer temperature is high, some vegetable farmers do not pay attention to reduce the drug concentration, once the drug concentration is too high, the leaf surface will change color or spots, and the leaf will also curl upward.

Third, excessive application of nitrogen fertilizer will lead to the increase of soil solution concentration, which will cause tomato leaflet to turn over and roll up; when the concentration of soil solution in saline-alkali area is high, the leaf will curl upward.

Fourth, coring too early is easy to make axillary buds grow, and the phosphoric acid in the leaves has no place to transport, resulting in leaf aging and leaf curling.

Fifth, virus is generally transmitted by aphids, whitefly and other virus-borne insects. The damaged tomato leaves will show symptoms such as chlorosis, shrinking, curling and so on. Leaf curl, mostly on the heart leaf and upper leaf, is easy to occur under high temperature and strong light.

Control methods of curling leaves on tomatoes:

First, carry out drought-resistant exercise after tomato planting to before fruit setting, timely watering and fertilization after fruit setting, and covering the sunshade net in midsummer to prevent high temperature and drought.

Second, the concentration of drugs should be reduced as much as possible in the summer high temperature season. Once the drug damage occurs, you can spray water or spray antidote to damage foliar fertilizer in time.

Third, the use of nitrogen fertilizer during the growing period of tomato should not be excessive, and the application of phosphorus and potassium fertilizer should be increased, especially in summer to prevent the overgrowth of tomato plants, the use of nitrogen fertilizer should be controlled. We should also choose to plant tomatoes in non-saline-alkali areas as far as possible, and soilless cultivation or soil improvement measures can be implemented in saline-alkali land.

Fourth, the removal of side branches of tomato is also called branching, which is generally carried out when it grows to more than 7 centimeters. If it is branched too early, the assimilation area of leaves will decrease, too many branches and leaves will be removed, and the aboveground growth of the plant will be poor, and at the same time, the development of root system will be affected. The ability of absorbing water and fertilizer is weakened, and then leaf curling is induced. It is common for tomatoes to branch, branch and pick too many leaves at one time, and this is the reason why curling leaves occur later.

The reason for the curling leaves of tomatoes:

First, the temperature difference between day and night in summer is small, in order to prevent tomato from falling flowers and fruits caused by overgrowth, it is correct for some vegetable farmers to spray naphthalene acetic acid, but when the concentration is too high, the tomato leaves will show rewind on the first and second day after spraying, and the leaves will return to normal on the third day. The general concentration of naphthalene acetic acid is 20-30PPM, but the concentration of naphthalene acetic acid exceeds 50PPM, the rewinding time may be longer, and some will drop flowers and fruits.

Second, the soil is too dry in the early stage and suddenly watered too much in the later stage, which will lead to the inhibition of leaf transpiration and reverse roll when the leaves show a state of self-protection.

Third, when dipping flowers with 2mem4murD at flowering stage, the concentration is too high or sprinkled on the leaves, making the leaves thicker, wrinkle or curl down. In addition, when cultivated in the field in spring, the surrounding wheat fields were sprayed with 2mem4murD butyl ester to control weeds in the wheat field, and the floating liquid was also easy to cause drug damage, resulting in abnormal curling of the leaves.

Control methods of curling leaves under tomatoes:

First, when the rewinding is serious, it can be alleviated by spraying Yeshuo tomato special disease-resistant liquid fertilizer.

Second, avoid excessive drought, but do not water too much after drought, especially at noon when the temperature is high.

Third, the concentration of dipping flowers must not be too high, and the usage should not be too large. Be careful not to drop the liquid on the leaves, and it should not be sprayed. When weeding with 2p4murD butyl ester, try to stay away from the vegetable greenhouse area as far as possible, or when the greenhouse is closed.

According to the above description, no matter whether the tomato rolls up or down, it has a great relationship with drug use, so it is recommended that growers, from the seedling stage, use tomato-specific disease-resistant liquid fertilizer (spraying) + tomato-specific seaweed long-term water-soluble fertilizer (flushing) to promote developed root system, good growth, less yellow leaves, long picking period, disease resistance, increase production and save fertilizer.