What is the problem with the yellowing or yellowing of the two sides of the main vein of the tomato

Tomato, also known as tomato, is a Solanaceae plant, an annual or perennial herbaceous plant, with the progress of the times, more and more people have a soft spot for tomatoes. Tomato has now become a well-known "Internet celebrity vegetable", and the reason why it is becoming more and more famous is that tomato is a vegetable that many people like to eat, and its nutritional value is also very high. When people planted tomatoes, they found that the leaves turned yellow, and many people simply thought that the weather was the cause and did not pay attention to it, resulting in a serious reduction in tomato yield.

<> low temperature can also cause yellowing of leaves, and when the temperature is too low, it is difficult for plants to absorb nutrients and cause yellowing of plants due to lack of fertilizer. Pay attention to the time of discharge and temperature changes. First of all, it is necessary to check whether there are pests and diseases in tomatoes, and if there are pests and diseases to strengthen drug management, if it is a lack of fertilizer and water, it should be applied more farm fertilizer, farm fertilizer, long fertilizer effect, high dish, good taste, beautiful appearance, and it is also very good for sales Iron deficiency and zinc deficiency is easy to cause yellowing of leaves, because iron and zinc are not easy to flow, although the root system absorbs iron and zinc is insufficient, but it can not be supplemented with the old leaves below, so it will cause iron deficiency and zinc deficiency in the growth site to yellow.

The yellowing of tomato leaves is just one symptom of the plant, which is called a pathology in plant pathology. However, only the symptoms are sometimes difficult to determine**, so it is necessary to combine other symptoms and symptoms on the plant, etc., the reason for the yellowing of tomato leaves may be: poor absorption of nutrients by the roots of the plant, or the utilization rate of nutrients is not high, and this situation is also related to improper fertilization of successive years.

During tomato planting, especially in autumn, yellowing of leaves often occurs. Tomato leaf yellowing is very common, don't panic too much, the main reason is temperature discomfort, improper fertilization, pesticide damage, virus disease, etc., as long as the organic titanium boron calcium foliar fertilizer is sprayed through the temperature tube in time, it can help to improve the photosynthesis rate of plants, so that nutrients are better absorbed and converted to plants, and reduce yellow leaves.

This is due to the malnutrition of tomatoes, which should be supplemented immediately with nutrient-rich chemical reactions.

It may be because you have watered too much and the roots are flooded, so you have such symptoms.

This shows that tomatoes are very lacking in nutrients and water, so it will lead to it, and we should also supplement tomatoes with some urea or compound fertilizer.

Tomato scab scab is a fungal disease, it is easy to occur in the environment of high temperature and humidity, mainly harms the leaves of eggplant, the small round spots of gray green can be seen on the leaves in the early stage of the disease, and the symptoms of the disease in the later stage are manifested as the small round spots expand to a large area of light gray-brown, generally speaking, if the concentration of the drug is too large, or the pesticide varieties used when spraying are exceeded, it is easy to produce pesticide damage, this situation is especially obvious at the beginning or end of spraying. Once it happens, it's irreversible. Unless the application time is not long, you can spray water to dilute the spots.

The final prevention and control method: pull the quilt in sections, properly shade after noon, and spray water or foliar fertilizer to strengthen leaf protection when the light intensity is high. This problem is a more complicated problem, because the yellowing of tomatoes is caused by many reasons, so different control measures should be taken according to different reasons, and the yellowing of crops is divided into two types: physiological yellowing and pathological yellowing.

Nutritional imbalances. Insufficient or excessive nitrogen, phosphorus and potassium fertilizers will lead to yellowing of leaves, which requires that when fertilizing, fertilization should be carried out according to the law of fertilizer demand at each stage of tomatoes, and blind fertilization should not be done.

High planting density, poor ventilation and heavy rainfall. It is easy to cause a large area of tomato leaf yellow. It is recommended to use pyrimycoamine or pythium or azoxycyclamine for prevention and control.

As one of the essential nutrients for tomato growth, iron is an important component of iron-containing enzymes in tomatoes. Iron-containing enzyme is a constituent substance of coenzyme in the process of chlorophyll synthesis in tomato, and it is also one of the combined components of pigments. Therefore, the lack of iron in tomato will cause the physiological symptoms of yellowing of the young leaves at the tip.

The young leaves of tomatoes are yellow, gray-yellow spots appear at the base of the leaves, expand outward along the leaf veins, sometimes the interveins are scorched and necrotic, the symptoms develop from the top to the stems and leaves, and the yellowed leaves between the leaf veins also grow on the axillary buds, generally too much phosphorus fertilizer is used in the soil, the soil is too wet, increase the application of organic fertilizer, adjust the soil pH, and apply sulfur powder on the alkaline soil to reduce the pH value. Foliar sprays of iron urea or ferrous sulphate can also be used.

It can be prevented with medication. Some pesticides can prevent tomatoes from developing these symptoms.

1) Increase soil temperature and promote root absorption. Generally speaking, leaf yellowing caused by physiological magnesium deficiency has little effect on fruit development.

2) Apply magnesium sulfate 2-4 kg mu.

3) Control the amount of nitrogen and potassium fertilizer, and excessive nitrogen and potassium fertilizer will have an impact on magnesium absorption.

The mesophyll is yellow, the veins are still green, and the leaves first appear in the middle and lower leaves or the leaves near the fruit, which is manifested as the leaves are spotted yellowing or yellow-whitening along both sides of the main vein, and the leaf tips, main veins and lateral veins remain green. It tends to occur during the fruit expansion period. The cause is physiological magnesium deficiency.

During the low temperature stage from October to March every year, due to the low ground temperature, the absorption function of the root system is affected, and it is caused by the inability to absorb magnesium. There are more fruits in the plant. In the case of root senescence, physiological magnesium deficiency is also susceptible.

Summary. This occurs when the root system of the plant absorbs nutrients poorly, or does not use nutrients well. In addition, this situation is also related to continuous stubble and improper fertilization, such as the application of non-rotten organic fertilizer caused by root burning, and long-term continuous application or excessive application of chemical fertilizer caused by soil compaction, and the high concentration of salt ions in the soil leads to poor root growth and uncoordinated nutrition.

What's the deal with yellowing of the top leaves of a tomato?

The pro is inquiring for you.

This occurs when the root system of the plant absorbs nutrients poorly, or does not use nutrients well. In addition, this situation is also related to continuous stubble and improper fertilization, such as the application of non-rotten organic fertilizer caused by root burning, and long-term continuous application or excessive application of chemical fertilizer caused by soil compaction, and the high concentration of salt ions in the soil leads to poor root growth and uncoordinated nutrition.

Summary. The yellowing of the leaves on the top of tomatoes belongs to the yellowing of tomatoes, which needs to be cleaned in time, crop rotation, irrigation and stuffy sheds for more than 15 days, and appropriately postpone the sowing date. Seedling stage:

The heart leaves are shriveled, the leaf color is slightly yellow, and the plant is short. Flowering period: The plant is significantly dwarfed and grows slowly.

Fruiting period: the disease is aggravated, the leaf edge is seriously rolled, the leaf quality becomes hard and the edge is small, and the fruit is not commercial. Late Growth:

The leaves are curled yellow and shrunken, but do not affect the yield.

The yellowing of the leaves on the top of tomatoes belongs to the yellowing of tomatoes, which needs to be cleaned in time, crop rotation, irrigation and stuffy sheds for more than 15 days, and appropriately postpone the sowing date. Seedling stage: the heart leaves are shrivelled, the leaf color is slightly yellow, and the plant is short.

Flowering period: The plant is significantly dwarfed and grows slowly. Fruiting period:

The disease is aggravated, the leaf edge is seriously rolled, the leaf quality becomes hard and the edge is small, and the fruit is not commercial. Late growth: the leaves are curly yellow and shrivelled, but do not affect the yield.

It grows vigorously and is not short.

The heart leaves are yellow. Okay, the reason for the yellowing of the upper leaves of the tomato is the lack of nutrient fertilizer. The yellowing of tomato leaves is caused by a lack of water and fertilizer.

The reason for the yellowing of the upper leaves of tomato is that the virus is infected, and the root system is injured and absorbed. It is a physiological disease that may be related to the lack of iron and zinc in tomatoes.

The heart leaves are yellow. The growth is very vigorous.

Tomatoes can only absorb nutrients through the roots, if the soil lacks water, it is easy to cause the branches and leaves to wither, and the leaves will show signs of yellowing.

It could be a lack of water.

If the watering is normal, the branches and leaves and the soil are not infected with fungal diseases, and the tomato has a yellow condition, it is likely that it is due to a lack of trace elements, and some trace elements can be supplemented regularly to make the tomato grow robust.

There is no shortage of water. If there is no shortage of water, see if it is a problem with trace elements.

It is a physiological disease: 1. Tomato potassium deficiency: the leaf margin of the middle and lower leaves of the tomato loses green and yellowing, and the yellowing is limited to the leaf edge.

Potassium deficiency can seriously affect the development of young fruits, reduce fruit quality, and also cause physiological diseases such as tendon rot. 2. Tomato magnesium deficiency: the lower leaves of tomato are generally yellowed and develop from bottom to top, mostly caused by magnesium deficiency.

When magnesium deficiency occurs, the leaves lose green, the chlorophyll content is low, and the photosynthesis is weak, which seriously affects the accumulation of organic nutrients and can cause a significant reduction in yield. Causes: Deficiency in facility cultivation has long been recognized as a cause of soil deficiency.

However, the occurrence of nutrient deficiency in facility cultivation is not caused by soil nutrient deficiency, but due to a combination of factors such as weak sunlight, low ground temperature, soil compaction, high soil solution concentration, severe hypoxia in the soil, low number of roots, root aging, low activity, physiological dysfunction, and poor ability to absorb fertilizer and water. The actual situation is that the amount of fertilizer applied in facility cultivation, whether it is organic fertilizer, or nitrogen, phosphorus, potassium, micro-fertilizer and other fast-acting fertilizers, is far more than the amount of fertilizer applied in the field, which is generally 5-10 times the amount of fertilizer applied in the field; On the contrary, the amount of watering for facility cultivation is only about half of the rainfall + watering amount in the field.

In the case of small amount of fertilizer, large amount of watering, and heavy loss of fertilizer, field cultivation does not occur, or rarely occurs, and nutrient deficiency disease does not occur! Could it be that the soil cultivated in facilities with a large amount of fertilizer, less watering, and less fertilizer loss is lacking in fertilizer elements? On the contrary, through soil testing, it was found that most of the facilities had significantly more fertilizer elements in the soil, and the concentration of soil solution was high.

Control methods: In view of the above reasons, in facility cultivation, maintaining a high soil temperature, creating suitable environmental conditions for root growth and development, improving the low temperature resistance and frost resistance of crops, promoting root development, and improving root activity are the most important technical measures for the prevention and control of nutrient deficiency and physiological diseases.

The middle and lower leaf margins of tomato lose green and yellow, and yellowing is limited to leaf margins, which is mostly caused by potassium deficiency. Potassium deficiency in tomato plants can seriously affect the development of young fruits, reduce fruit quality, and cause physiological diseases such as tendon rot. Potassium deficiency has been more common in recent years, and the reasons are that the use of organic fertilizers is low, and attention is not paid to increasing the application of potassium fertilizers; Second, the vegetable field has a large amount of watering, serious potassium leaching, and a large amount of potassium required by tomatoes, so it is easy to show potassium deficiency; Third, the soil temperature in the greenhouse is low, which affects the growth and development of the root system, and the root system is underdeveloped, low activity, and poor absorption capacity, which is very prone to potassium deficiency and other deficiency diseases.

In order to prevent the occurrence of potassium deficiency, the indoor soil temperature should be increased firstly, so as to promote root development and improve fertilizer absorption capacity. Second, pay attention to spraying or watering "Tianda 2116" to promote hair roots, improve the absorption capacity and stress resistance of tomato plants and roots. Third, organic fertilizer and potassium fertilizer should be added, potassium fertilizer should be applied in the fruiting period, and combined with spraying, potassium dihydrogen phosphate sprayed outside the root (note that it cannot be mixed with manganese and zinc) and potassium sulfate.

A disease is not necessarily a disease, and I think there may be a number of reasons:

1. Water, too much water is easy to cause the roots not to breathe, serious root death, which affects the water absorption of the plant, of course, less water is also easy to plant yellow.

2. Light, if the light is not enough for a long time, the yellow leaves will be yellow, and the sun exposure of potted plants should also be avoided.

3. If the temperature is too high, it will wither.

5. The fertilization is too heavy, and the leaves are burned and the buds are burned.

The landlord's description is not detailed, and it is recommended to compare which reason is the right medicine, hehe.

Tomato bacterial spot disease, mainly harming leaves, produces water-stained small dot spots at the beginning of the disease, dark brown after enlargement, and turns brown or black in the middle and late stages of the disease. The stems, leaves, vascular system, and xylem do not change brown.

Prevention and control methods start spraying at the beginning of the disease, spray once every 7 10 days, and continue to control 2 3 times. The agent can choose 47% Garinon wettable powder 600 800 times liquid (125 165 grams per mu), 700 times Pulik water-soluble liquid (130 grams per mu), 800 times Fenghu amine wettable powder (125 grams per mu, 600 times DT wettable powder (165 grams per mu, 700 times wettable powder (130 grams per mu).

Tomato leaves are deficient in magnesium, generally because the tomato root system is not good, or excessive potassium fertilizer leads to the absorption of magnesium, you can spray amino acid foliar fertilizer plus magnesium sulfate or calcium magnesium nitrate, and spray it continuously once every 5 days.

Spot is tomato early blight, has begun to live, the adult stage of the leaf is damaged, mostly from the lower leaves of the plant upward, the initial water-soaked dark green lesion, after the expansion of the round or irregular shape of the ring spot, the edge has a light green or yellow halo, the middle is concentric ring, when the wet spot grows black mold, when the leaf falls off. It can be used with flusilazole, benzo. Azoxystrobin, iprodione, bromonitrile, pyraclostrobin and other foliar fertilizer sprays were sprayed continuously every 7 days.