Farmers who grow tomatoes know that there are many pests and diseases of tomatoes, especially tomatoes grown in greenhouses. Among them, there are more tomatoes, which are the phenomenon of tomato leaf rolling. The leaf is divided into leaf curls and physiological leaf curls caused by the disease. Today, Xiaobian will introduce the symptoms, causes, preventive measures and precautions of the tomato leaf.
First, the symptoms of tomato leaf curl
The leaves of the rolled leaf are curled upwards on both sides. In severe cases, the rolled leaves are simple, and the leaves become thick and brittle. Rolling leaves are the most common symptom in tomato cultivation, and the degree of lightness and weight of the leaf is very different. From the whole plant point of view, some plants only have lower leaves and leaves, some are only the middle and lower leaves, some are the top leaves, and some are the whole leaves.
Second, the reasons for the tomato leaf
1. Variety Variety Some early maturing varieties, loquat varieties and varieties with weak disease resistance are prone to leaf rolling.
2, poor water absorption capacity, poor root development, or injury, seedlings are not timely seedlings, plant root water absorption capacity is reduced, easy to roll.
3. The soil moisture or nutrient conditions are not suitable. Soil dry early water shortage, or excessive soil moisture caused by root hypoxia, or low organic matter content in soil, or lack of nutrients such as phosphorus, potassium, calcium, magnesium, iron, manganese, copper, or excessive application of nitrogen fertilizer In particular, too much ammonium nitrogen causes curling.
4. The temperature is not suitable for daytime temperatures exceeding 35 degrees, or nighttime temperatures below 6 degrees. Or the temperature is high, and the relative humidity in the air is low.
5, the blade is too fast to lose water, such as a cloudy day after a cloudy day, or the temperature inside the protection ground is high and suddenly a large release, so that the blade is too fast to lose water.
6. Pruning improper planters are prone to curling when they are pruning and picking the heart too early or too heavy.
7. Plant growth is poor. Tomato plants are prolonged, or the plant growth is too weak, or too many plant results may occur.
8. Diseases caused by disease or phytotoxicity Plants infected with virus disease, leaf mold, or suffering from mites, or 2, 4 - drops of phytotoxicity, are easy to induce plant leaf rolling.
Third, the prevention measures of tomato leaf rolling
1. Choose the superior species that are not easy to roll, or have strong resistance to stress.
2, to protect the root system development using nutrient é’µ root protection seedlings, or timely seedlings, to cultivate age-appropriate disease-free seedlings. After the seedlings are slowed down, it is necessary to pay attention to the control of water seedlings, and avoid root damage during the operation of farming.
3. Strengthen field management
Apply enough fully decomposed organic fertilizer as base fertilizer, cover it with plastic film, and frame it at the right time. After entering the fruiting period, the topdressing and watering of the first ear and the second ear should be followed by the application of nitrogen, phosphorus and potassium compound fertilizer to supplement the nutrients and promote the growth of the tomato branches and leaves. Make timely and proper watering to keep the soil moist. In the hot season, it is necessary to change the watering in the evening. In the low-temperature season, it is necessary to adopt insulation measures in the low-temperature season. In the hot season, measures should be taken to reduce the wind or to release the wind for a long time.
4, pay attention to cover the sunshade when the light is too strong, you can use the shade net to cover.
5, timely and reasonable pruning
Pruning at the right time (usually when the length of the side branches is more than 7 cm). When the plant grows vigorously, the side branches can be removed early; when the plant grows weak, the side branches can be delayed. When tying the vines, the ears should be adjusted to the inside of the rack to adjust the leaves to the outside of the rack; when topping, 2-3 leaves should be kept on the top inflorescence to prevent strong sunlight from burning the fruit.
6, to avoid the occurrence of phytotoxicity, the rational use of plant growth to regulate the treatment of flowers to prevent phytotoxicity.
7. Foliar fertilizer is introduced into the fruiting stage, and the leaf surface is sprayed with 0.3% potassium dihydrogen phosphate solution.
8, prevention and treatment of disease, timely prevention and treatment of viral diseases, leaf mold, mites and so on.
9. Spraying the heat-resistant agent with the copper sulfate 1 000 times solution or the zinc sulfate 1 000 times solution to spray the plant can improve the heat resistance of the plant.
4. Remedial measures for tomato leaf rolling
1. Rolling leaves caused by improper management should take early improvement measures to take management measures to improve environmental conditions.
2, pay attention to avoid the occurrence of sunburn fruit early removal of sunburn fruit, cover the sunshade net, you can increase the number of watering or watering.
Five, the note of the tomato leaf
1. The plant causes leaf rolling due to its weak growth, which occurs mostly during the fruiting period.
2. Generally, the leaves of the plants at the vents will be heavier.
3, lack of nutrients caused by the leaves, when the nutrient elements are insufficient, it will be accompanied by small leaves, deformed, necrotic spots, leaves become purple, yellow, brown and other symptoms.
4, the leaf caused by excessive nitrogen, when the ammonium nitrogen is too much, will be accompanied by the rib bulge in the leaflets on the mature compound leaves, the leaflets are inverted stern shape; due to too much nitrate nitrogen, accompanied by lobular curling symptoms.
5, the leaf caused by the phytotoxicity, generally 2, 4 - drops of phytotoxicity, will accompany the new blade deformity shrinkage.
6, the leaf caused by the virus disease, will accompany the leaves chlorotic, smaller, frustrated leaves, the fruit is convex and concave unequal symptoms.
7, the leaf curl caused by leaf mold, accompanied by yellow spots on the leaves, grayish brown velvet mold on the back of the leaves and other symptoms.
8, the wrinkles caused by the sassafras, will be accompanied by narrowing of the leaves, stiff erect, wrinkled or twisted deformed, and finally bald and other symptoms.
The above are the symptoms, causes, preventive measures and precautions of the tomato leaf rolling. The leaf curl will cause the sunburn of the tomato, and the strong light will directly shine on the fruit surface, so that the number of fruit burning will increase, and many fruits will be diseased, resulting in the fruit of the victim. There is no commodity value, which affects the income of farmers, so farmers must pay attention.
For the wonderful pictures and popular comments on the tomato leaf, you may be interested in the following recommended content, welcome to read.
Packing Net or Glass Bottle Net
Packing Net,Packaging Nets,Packaging Net,Fruit Packaging Net
Changzhou Satidi Import and Export Co., Ltd. , https://www.guanjiejts.com