First, poor root development, injury damage, weak water absorption capacity, and the lack of water in plants. Second, the temperature is abnormal. When the temperature exceeds 35°C, not only photosynthesis is weakened, but also the structure of the chloroplasts is destroyed and the leaves are wilted. When the nighttime temperature is lower than 6°C, there will be a low-temperature barrier, so that the back of the upper leaves of the plants will turn upward and the leaves will be dark green and dull. Leaf margins gradually become dry or individual leaves wilting and dry. Third, high temperatures and dry soils. High temperature leaves have large water transpiration and more water loss. In order to reduce the transpiration of water, the stomata on the leaves closes, resulting in the blade gathering or curling, which is a physiological protection. Fourth, excessive soil moisture. Not only did the roots grow slowly, the roots became shallow, and when the roots became dark, they died. Furthermore, excessive soil moisture led to a decrease in the oxygen content of the soil, and the roots were subjected to anaerobic respiration, which forced the root system to undergo anaerobic respiration, resulting in anaerobic respiration. Alcohol, lactic acid, etc., are accumulated in plants to cause poisoning to the plants, resulting in malnutrition in the plants and rolling leaves. Fifth, the booth suddenly exploded. In particular, under the action of dry wind, a large amount of water leaves on the windward side of the plant can be wilted, causing the leaves to gather up or curl up. At the same time, a large amount of air will reduce the temperature inside the greenhouse. If the temperature is too low, the back of the upper leaves of the plants will roll upwards. Shrink. 6, lack of nutrition. The low content of organic matter in the soil and the lack of essential elements all cause abnormal plant growth. In particular, when the fruit is sitting or after harvesting the fruit, it needs a lot of nutrients. If there is no effective supply, the first fruiting leaves will be slightly curled. Or, the whole plant leaves are tube-shaped and become brittle. Seven, iron deficiency, manganese and other trace elements in the soil. Will also roll leaf, this leaf is often accompanied by yellowing and purple leaves and other symptoms. VIII. Over-application of nitrogenous fertilizers, especially when there is a large amount of nitrate nitrogen, the small leaves curl. Nine, pruning, picking up too much, too few leaves on the plant. There are few photosynthetic products produced by the leaves, which can not meet the needs of fertility, affect the normal metabolic activities, and thus the leaf upturn phenomenon. In addition, when the pruning and picking are done too early, the phosphate absorbed by the roots is transported upwards through the lower leaves to the upper fresh leaves. Since the pruning is transported too early, it accumulates in the lower leaves and hardens and curls. Tomato leaf rolling performance: upper leaf and lower leaf Reasons for curling tomatoes: First, after the fruitful period of the entrance, the tomatoes encountered high temperature and dry weather and could not add water in time. At this time, the leaf area was large, and the high temperature and strong light enhanced the transpiration of the leaves, and the lower leaves of the plants were easy to curl up. Especially at the vents, the rolls of tomatoes are often heavier. Second, summer temperatures are high. Some growers do not pay attention to lowering the drug concentration. Once the drug concentration is too high, phytotoxicity occurs, the surface of the leaves will change color or spot, and the leaves will also curl up. Third, excessive application of nitrogen fertilizer, resulting in an increase in soil solution concentration, will cause the tomato leaflets to turn over, roll; saline-alkali soil solution concentration is high, there will be upward leaf curling phenomenon. 4. It is easy for the picking buds to breed prematurely and the phosphoric acid in the leaves has no place to transport, causing the leaves to age and the leaves to curl. V. Viral diseases are generally transmitted by insecticidal insects such as aphids and whiteflies. Damaged tomato leaves appear chlorotic, smaller, wrinkled, and curled. Leaf curling, mostly manifested in the heart and upper leaves, prone to occur under high temperature and strong light. Tomato rolls on the coping method: First, after the planting of tomatoes to drought-proof exercises before fruit setting, timely watering and fertilizer application after fruiting, cover shade nets in midsummer to prevent high temperature and drought. Second, the high temperature season in summer should try to reduce the drug concentration, once the phytotoxicity occurs, can be sprayed or sprayed with alizarin lactone in a timely manner. Third, the use of nitrogen fertilizer during tomato growth should not be excessive, increasing phosphorus and potassium fertilizers, especially in summer to prevent tomato plant growth, but also should control the use of nitrogen fertilizer. It is also necessary to choose to grow tomatoes in non-saline areas. Saline-alkali land can be soillessly cultivated or soil reformed. Four, removal of tomatoes Lateral branches also called snoring, generally in its length to 7 cm or more, if the snoring is too early, the leaf assimilation area is reduced, to excessive foliage, plant growth in the aboveground, while affecting the development of the root system , Absorption capacity of water absorption and absorption, and then induce leaf curling. Commonly there are tomatoes once to branch, snoring, picking leaves too much, after the leaf curling is the truth. 5. Use anti-virus varieties. Seeds should be soaked with 10% trisodium phosphate for 20-40 minutes with clean water. Spray imidacloprid or acetamiprid to prevent aphids and other transmission pests, and spray the virus A500 times mixed with ningnan meromycin 300 times antivirus disease, it is indirect protection against leaf rolling. The reason for the curling of tomatoes: First, the temperature difference between day and night in summer is small, in order to prevent tomatoes falling due to leggy caused by fruit, some farmers spray naphthalene acetic acid is correct, but the concentration is too large, the first two days after spraying tomato leaves will show rewind, the third day The leaves will return to normal. Generally, the use concentration of naphthalene acetic acid is 20-30 PPM, but the use concentration of naphthalene acetic acid exceeds 50 PPM. The rewinding time may be longer, and some will fall. Second, the previous period of excessive drought in the soil, sudden excessive watering in the later period, will lead to inhibition of leaf transpiration, the leaves show self-protection will appear when the rewind. 3. When 2,4-D is used for flowering, the concentration is too large or sprinkles on the leaves, making the leaves thicker, shrinking or curling downwards. In addition, spring is cultivated in the field, and 2,4-D butyl ester is sprayed around the wheat field to control weeds in the field. The floating of the liquid medicine is also likely to cause phytotoxicity, resulting in abnormal deformation of the leaves. Tomatoes under the rolling leaf coping methods: First, when the rewinding is severe, the cytokinin can be sprayed with more than 6,000 times the amount of love. Second, avoid excessive drought, but do not water too much after the drought, especially pay attention to avoid pouring water at high temperatures at noon. Third, the use of 2,4-D when the concentration must not be too high, the amount used should not be too large, be careful not to drop the drug on the leaves, should not be sprayed, with 2,4-D butyl ester weeding Keep away from vegetable sheds or apply when closing. In short, no matter whether the tomato leaves are curled upwards or downwards, they are all physiological diseases. As long as the above-mentioned corresponding measures are taken in production to strengthen the cultivation and management, these physiological diseases naturally occur or even do not occur. Poly-Lok Endo Appliers,Laparoscopic Hemoclip Applier,Vascular Clip Applicator,Surgical Clip Applier For Slae Qingdao DMD Medical Technology Co., LTD , https://www.conston-tech.com
Causes of tomato physiological curling mainly include the following aspects: