Regardless of greenhouse tomato or open-air tomato, especially in high temperature and drought environment, it is prone to leaf curling with different symptoms. There are five main reasons: 4. The lack of disease. The lack of phosphorus showed purple backs, brown spots on the leaves, the lower leaves rolled up, the leaves turned yellow, and the tip dark brown withered. Can be applied to soil by applying phosphate fertilizer, or foliar application of 0.3% potassium dihydrogen phosphate solution. Magnesium deficiency manifests as: In the first inflorescence, the ash of the lower part of the inflorescence is chlorotic. The yellowish phenomenon appears between the veins. Then it expands upwards to form the yellow variegated leaves. In severe cases, the leaves are stiff or the edges are rolled up. Necrotic spots or brown bands. Magnesium deficiency can be solved by applying 100% solution of full-element fertilizer or foliar spray magnesium sulfate. 5. Hormonal injury. In the prevention of flowering and fruit drop, the use of plant hormones, such as 2.4-D carelessly, stick to the young leaves or growing points, there will be bent leaves or growth points, new leaves can not be normal expansion, green distorted leaf shape. Prevention and control measures: Select the appropriate concentration when using, generally use 20mg/kg ~ 15mg/kg, when the temperature is high, the concentration should be lower. When using, pay attention to prevent the liquid from sticking to the leaves or growth points, and do not spray it. In the event of a phytotoxicity, some nutrient solutions can be given, such as natural brassinolide and love overdose. Emergency Blanket; First-aid Aluminum Foil Blanket; First-aid Blanket; Aluminum Foil Blanket; Aluminum Blanket; Foil Blanket; Emergency Blanket; First-aid Aluminum Foil Blanket; First-aid Blanket; Aluminum Foil Blanket; Aluminum Blanket; Foil Blanket; Luck Medical Consumables Co.,LIMITED , https://www.luckmedical.com
1. Virus disease damage. Virus disease can easily lead to curling of tomato plants, leaf curling and clustering. In severe cases, there are only veins but no mesophyll. Viral diseases are transmitted through contact with poisonous aphids, whitefly, or sap, and high temperature and drought are favorable for this. Control measures: selection of disease-resistant varieties; implementation of crop rotation to reduce the initial infestation source; spraying 1000 times potassium permanganate at the early stage of the disease; using 10% net 1500-2000 times to kill the aphid and acaroid mites.
2. Physiological roll. Before and after the harvest of the tomato, the first ear was slightly rolled, or the whole leaf was curled into a tube and became brittle. This was mainly due to high temperature and drought, and the stomata of the tomato was closed and the leaf curled. Preventive measures: timely watering and fertilizer application after fruiting, covering the shade net, cover during sunny day and night, exposing at night, and not covering cloudy days.
3. Astragalus damage. Symptoms are narrowing of the blade, stiffness, erection, shrinkage or distortion, and finally, baldness. The control agent can be used 1.8% afordin 3000 times.
Tomato leaf roll is a thing