Why yellow spots appear on tomato leaves in a greenhouse and how to save your tomato harvest

• Vegetables

04.06.2019 53366
VK

Spots on tomato leaves are a good indicator of plant health. If you regularly monitor the condition of tomato leaves, you can diagnose the cause of the disease or a nutritional disorder of the bush. Early identification of a problem will help you quickly find out the causes and promptly take measures to eliminate them.

There can be several reasons for the appearance of spots on plants. As a rule, their appearance signals the onset of a disease to which tomatoes are very susceptible. Typically, various spots on tomato leaves begin to appear in the second half of summer, closer to the end of fruiting and harvest. This is quite understandable, since during this period the summer heat still lingers during the day, but the night temperature has already dropped significantly. In addition, there are fogs and cold dew in the mornings, which contributes to the occurrence of fungal diseases. Also, spots may indicate a deficiency or excess of a certain nutrient or gross errors in agricultural technology when growing tomato bushes.

So, let's look at the most common reasons for the appearance of spots on tomato leaves.

Stains left by pests

At the seedling stage, tomatoes should not have pests. It is the gardeners’ fault that they appear. Stains can be left by:

1. Whitefly. This is a gnawing pest, but you can’t avoid it. Firstly, the whitefly lays eggs that look like white spots; the larvae leave yellow dots when feeding. And secondly, the insect is a carrier of sooty fungus, which causes the leaves to turn black.
2. Spider mite. The first manifestation of the pest is yellow dots on the leaves of seedlings. The underside of the plate is covered with a gray coating and thin cobwebs. Appears when indoor flowers are close together or is carried by people and pets. Spreads in dry air and high temperatures.
3. Aphid. A sucking pest, it leaves dots on the leaves, but it is impossible to see them under a layer of small insects. They themselves look like elongated black or red spots.
4. Nightshade miner. Quarantine pest of open and protected ground. The greatest danger is posed by larvae that gnaw passages inside the leaves and leave transparent spots. It is found in the soil and on seed material, from where it gets onto tomato seedlings.

Pests need to be controlled with insecticides, preferably systemic ones. It is difficult to destroy spider mites; the preparations must have an acaricidal effect.

Infectious diseases

The appearance of spots on tomatoes caused by microorganisms is common. In seedlings, they usually appear overgrown, ready for planting in the ground or greenhouse.

There is no cure for viral diseases. Bacterial and fungal infections are controlled with appropriate fungicides. It is imperative to regulate care, since the spread of infection is usually accompanied by high temperature and humidity, and lack of ventilation.

White spots

White spots on tomato seedlings can be caused by infectious diseases:

1. Powdery mildew. Fungal disease. Spots appear, eventually covering the entire leaf. It is a coating that really looks like flour, as can be seen in the photo. Usually, already picked seedlings suffer. The spread of the disease is facilitated by high temperature, humidity and excess nitrogen.
2. Septoria. This fungus is called white spot. Starting from the lower leaves, frequent dots of the corresponding color appear. Then they merge, turn brown, and the plate dies.

Yellow spots

Diseases of seedlings, the external manifestation of which is yellow spots on tomato leaves:

• Root rot. A fungal disease, one of the signs of which is yellow spots on the leaves. At the base of the stem, a brown coating and constriction are clearly visible.
• Fusarium wilt. Fungal disease. It begins with wilting of the top and yellowing of the lower leaves of tomatoes.
• Mosaic. Virus. Yellow dots appear only on young leaves. Gradually they grow and form a bizarre pattern. There is no cure.
• Bacterial wilt. Tomato leaves turn yellow. If the tomato seedlings are large enough, aerial roots form on the target.

Black and brown spots

Dark spots may appear on seedlings due to disease damage:

• Cladosporiosis or brown spot. The fungus is very similar to septoria, only the spots literally immediately become dark. It rarely affects seedlings.

• Sooty mushroom. Appears only in close proximity to infected indoor flowers. Looks like a black coating.

How to help a plant with yellowness?

If the diagnosis is successful, then measures must be taken, otherwise all the yellowing seedlings will die. For prevention, you need to perform a number of simple steps.

• Periodically loosen some of the soil before or after watering. This is done in beds with young tomatoes, planted from pots in greenhouse or greenhouse conditions.
• Plants do not like excess moisture; they need to be watered in a special way. The classic method is rare watering strictly at the root with a good volume (up to 5 liters per hole). In order not to disturb the temperature and humidity in the greenhouse or greenhouse, it is better to water in the first half of the day.

During mineral starvation, fresh tomato seedlings, on the contrary, are treated by leaves, but with a special solution. It is necessary to dilute 1% mineral salts in water and treat the yellowing leaves of the transplanted seedlings for the first few days. This approach is very useful for tomatoes and beneficial for the soil ecology.

Treating yellowed tomatoes with drugs is possible, but not advisable. Typically, gentle stimulants such as Epin are used. The drug, of course, will restore the root system and stimulate the growth of fresh leaves, but it is no longer organic.

Spider mites on a tomato leaf

Preventive measures

Determining the cause of yellowing tomatoes is not easy. It is much easier to follow simple measures that will keep the seedlings healthy:

• observe moderation in watering;
• maintain optimal temperature and humidity levels;
• apply fertilizers in a timely manner;
• monitor the condition of plants in order to recognize diseases in time;
• pest control;
• compensate for the lack of useful microelements;
• do not neglect preventive treatment with fungicides;
• follow the rules of crop rotation;
• regularly disinfect garden tools;
• treat the soil and seed material before planting.

Possible causes of yellowing leaves

Yellowing of leaves is a common phenomenon both indoors and outdoors. Why do the stems and foliage of tomatoes turn yellow? A change in the color of the tops can be caused by errors in care, diseases or an imbalance of substances in the soil.

When yellowing appears on the leaves, do not panic - it is important to quickly and correctly identify the source of the problem

Lack of fertilizers

Lack of nutrients negatively affects the condition of plants

To correctly determine which substance is too little, you need to pay attention to which part of the plant the yellowing began

What happens when there is a deficiency of specific elements:

1. Nitrogen. If there is a shortage, the tops turn yellow or discolored. Young leaves grow small, and the plant itself weakens. Lack of nitrogen also negatively affects fruits.
2. Phosphorus. The appearance of yellow spots on the lower leaves is also characteristic of a lack of phosphorus. The leaves become smaller, their edges curl, and the stem takes on a purple hue.
3. Potassium. The lower leaves of the seedlings turn yellow, curl and die, and the stems become stiff. Changes begin from the edges of the leaf plate, new leaves grow small and thick.
4. Zinc. In addition to yellow spots, brown and gray blotches appear on the foliage. Over time, the leaves die off.
5. Magnesium. The foliage color changes to yellow between the veins. New leaves curl inward, and old ones become covered with brown spots and fall off.
6. Bor. The upper leaves become covered with yellow spots, the veins turn brown. The plant grows in width and sheds flowers.
7. Sulfur. First, the upper leaves turn yellow, then the changes affect the lower branches. The tops become brittle and brittle.
8. Iron. Yellow spots appear in the middle of the leaf blade and along the veins.
9. Manganese. Yellowness appears in the middle of the leaf; near the veins, the color of the spots is heterogeneous, yellow-green.
10. Molybdenum. The first pair of true leaves turn yellow and curl upward. The color change begins with the appearance of small yellowish spots, then covering the entire surface of the plate. The leaf veins remain green.

Root damage

The root system is responsible for feeding the entire plant. Its damage negatively affects the foliage.

A change in the color of the tops can be caused by a depressed state of the roots, which occurs for various reasons:

• pest damage;
• weakening due to excess vegetative mass;
• transplant injuries;
• deep loosening of the soil;
• poor quality seedlings.

Most often, yellowing of foliage is caused by a weakening of the root system, which cannot cope with the nutrition of the tops. The result is starvation and leaf death. The color change of the tops begins from the bottom of the plant.

Often the reason for insufficient development of the root system is poor-quality or improperly prepared seedlings. The plant was grown in small containers, which constrained the roots. Such plants have abundant green mass, elongated upward. After the transplant they often get sick.

Sunburn

Lighting plays an important role in seedling growth. Excessive sunlight can cause foliage to burn and turn yellow. This usually happens during a period when the plants are weakened after being planted in the garden.

The tops may also turn yellow due to lack of light. Thickening of plantings leads to the fact that plants do not receive enough light. As a result, the lower and middle leaves begin to change color and fall off.

Excess moisture

A lack of moisture, as well as its excess, negatively affects the health of tomatoes. With insufficient watering, plants begin to save moisture, trying to reduce its evaporation. In this case, the leaves are rejected.

When there is a lack of moisture, the leaves first curl, then their color changes and they fall off.

With abundant watering, the plant forms excess green mass, the nutrition of which the roots cannot cope with. This leads to insufficient development of the root system and poor absorption of nutrients from the soil. Yellowing of foliage with excess moisture occurs due to a lack of nitrogen.

Plants grown in a greenhouse or greenhouse may turn yellow due to high humidity. The optimal humidity level is 60-70%; as the indicator increases, the tops begin to rot. The situation may be aggravated by low air temperatures.

Pests

Insects can also cause tomato leaves to turn yellow and die:

• whitefly;
• aphid;
• tobacco thrips;
• Colorado beetle.

How to identify the cause

First of all, a visual inspection of the plants is necessary.

Attention should be paid to the following details:

• which leaves are affected by spots - upper or lower;
• on which surface of the leaf plate there is plaque - upper or lower;
• do the spots spread to other vegetative organs - stems, flowers, ovaries and fruits;
• vein condition;
• the presence of damaged vessels on the cut.

Then you should analyze the agricultural practices and conditions for growing tomatoes:

• watering;
• feeding;
• lighting, temperature, ventilation of the greenhouse.

By comparing the symptoms of diseases and the consequences of violations of agricultural practices with the identified problems, we can judge the cause of yellowing of tomato leaves.

Possible diseases

Yellowing of foliage is the first symptom of many diseases.

Diseases that cause yellowing of tops:

1. Chloratic curl - the plant droops and looks weakened, the leaves turn yellow and the roots rot.
2. Cladospirosis - a dark coating appears on the lower part of the bush, which turns yellow over time. The spots spread throughout the plant, and the damaged areas die off.
3. Septoria blight - the lower old leaves are affected first. A small spot appears on the plate, which gradually grows, acquiring a dark outline. The leaves dry out, the stem turns yellow, and the plant dies.
4. Mosaic - the leaf acquires a heterogeneous yellow-green color, deformation of the leaves and fruits occurs, and then their necrosis.
5. Powdery mildew - small yellow spots and white coating appear on the leaves. As the disease progresses, the formations become covered with a damp substance, the fruits crack and rot, the flowers turn black and fall off.
6. Gray rot - the stem becomes covered with gray-brown spots, light stripes appear on it, the leaves turn yellow.
7. Late blight - a white coating appears on the underside of the leaf, then brown oval spots form on the damaged areas, which then spread to the stem. At the same time, the fruits turn black.
8. Brown spot - yellow spots appear on top of the leaf blade, and brown spots on the bottom. The disease develops from the lower branches, gradually affecting the entire tops.
9. Alternaria blight - the leaves turn yellow, black spots appear on them, tissue necrosis occurs and the tops die. Blackened areas form on the fruits.

Dark sunken spots on tomatoes - Alternaria

There are rounded dark depressed spots on the leaves, stems, and fruits. This disease manifests itself in hot weather - Alternaria (macrosporiasis). The size of the spots can reach several centimeters and they will be dry in any weather. The disease causes yellowing of the plant's leaves. A distinctive sign of its appearance is spots of black plaque on the leaves and fruits.

What to do? Treatment with fungicides: Quadris, Hom, Ordan, Profit Gold, Oksikhom, Bordeaux mixture. Treatment with biofungicides: Alirin, Fitolavin, Fitosporin M, Trichodermin

Prevention

The best disease prevention is monthly treatment with chemicals, insecticides, fungicides or biological agents. For example, Aktara can treat fungi, viral diseases of tomatoes can be treated with a solution of karbofos, and in case of bacterial infection – with carbothione.

Follow the timing of fertilizer application. They can be found in the instructions for a particular mineral complex. When flowering, you don’t need to focus on it - fertilize it once every 2 weeks.

Take care of the soil in the fall. You can buy litmus paper at a gardening store and measure the acidity level. If the level is elevated, it must be reduced until the end of autumn, since a decrease in early spring can lead to the death of seedlings.

Don't want to damage the roots? Then carry out hilling and loosening after watering and slightly deepen the hoes and rakes.

Nutrient deficiencies and excesses

It is interesting that curling, yellowing, followed by drying of the foliage and falling of the fruits, is observed both with a lack and with an excess of nutrients in the soil.

• Nitrogen is the best friend and enemy of tomatoes. Excess nitrogen is expressed in curling and increased fragility of leaves on the bush. The deficiency is noticeable in the stunted, pale-colored leaves of the plant.
• Potassium is an immunity aid. With its deficiency, the leaves shrink inward, the edges are bordered with “rust”. An excess of this microelement leads to stunted growth, mosaic pigmentation of foliage, its curling and death.
• Phosphorus is especially important in the early stages of development. Phosphorus starvation leads to leaves curling on the wrong side, changing their color from green to brown-brown.

Many symptoms of deficiency or excess of microelements are very similar in appearance. In addition, with a significant deficiency or excess of one of the elements, the plant’s absorption of others is disrupted.

If visually it is not possible to correctly determine the cause of the disease, then it is better to use complex fertilizers in which nutrients are specially selected for the full development and growth of tomatoes in optimal proportions.

Fertilizers that have proven themselves well are: Ammofoska, Nitrophoska, Diammofoska, Nitroammofoska, Kristalon for tomatoes, Red Giant, Krepysh, Kemira (Universal, Lux), Mortar.

How to cure

Almost all fungal diseases of tomatoes are treatable. If a set of measures is carried out in time, the disease stops at an early stage and the harvest is not lost. The exception is tomato mosaic in the later stages. To stop the spread of the virus, it is necessary to treat the soil and seeds before planting.

Daily inspection of the bush, proper watering, shading of the plant and fertilizing will be the key to a good harvest. What preparations are recommended for a beginning gardener:

"Kuproksat"

Against late blight - “Thanos”, “Kuproksat”, “Ordan”.

For the treatment of fungal infections and increasing immunity - “Previkur”, “Profit” and “Ridomil Gold MC”.

Yellow and white spots on tomato leaves

Most often, light spots on tomato leaves indicate a viral or fungal disease.

Mosaic

Yellow and light green spots on tomato leaves.
Mosaic. Plantings affected by the mosaic virus can lose up to half the harvest. The disease manifests itself at the initial stage as a “mosaic” pattern on the leaves, consisting of alternating yellow and light green spots. Subsequently, individual areas on the leaves darken, and the leaf blades themselves curl. The plant sharply slows down and cannot set fruit. Infection of surrounding plants occurs very quickly.

Often the mosaic occurs “in combination” with another viral disease - streak - which manifests itself as dark necrotic spots on the leaves, as well as dark stripes on the stems and petioles.

How to fight? Viruses are transmitted by insects, as well as through contaminated seeds, so it is necessary to take timely measures to combat pests, as well as treat the seeds before sowing. Infected plants themselves cannot be treated; they will have to be dug up and destroyed. At the very initial stages of the disease, treating tomatoes with 10% whey can help. To stop the spread of infection, the soil should be treated with fungicides (Kuproksat, etc.) or steamed at high temperature.

Read more on the topic

Mosaic of tomatoes

Detailed description of the tomato mosaic virus with photographs. Causes of the appearance and spread of the disease.

Septoria (white spot)

Dirty white spots with dark edges on tomato leaves.
White spotting. The fungus primarily affects leaf blades, which become covered with small, watery, dirty-white spots with a dark edge. Large old leaves are affected first, then younger ones. The parts of the leaf that are not affected by spots turn yellow and die over time. As a result, the growth and development of the plant is greatly slowed down. Most often, tomatoes are affected in open ground under waterlogged conditions.

How to fight? To prevent septoria, plants are treated with the already familiar 1% Bordeaux mixture or 0.3% copper oxychloride suspension, crop rotation is observed, the soil is disinfected and dug deep, and the seeds are treated. During the initial infection, you can help the plant by promptly removing the affected leaves; if the infection is severe, you will have to dig up and destroy the damaged bushes.

In any of the cases described above, it is important to remember that the disease is easier to prevent than to treat, therefore preventive measures and careful adherence to agricultural practices for growing tomatoes should be mandatory items in your gardening

Continuing the topic

Septoria (white spot) of tomatoes

A detailed description of the causes and signs of tomato septoria (white spot). Photos with explanations.

Green and yellow spots on tomatoes - tomato mosaic

In tomatoes affected by this disease, a characteristic mosaic pattern appears on the tops in the form of alternating green and yellow spots. In young leaves, the mosaic pattern is more clearly visible than in older leaves. The disease spreads very quickly to nearby tomato bushes. In the future, yellowish spots may appear on the fruits. This is tomato mosaic , a viral disease. The virus is transmitted by insect pests in the soil, but first of all, infection occurs with seeds. Therefore, to prevent mosaic, it is necessary to choose seeds of hybrids that are immune to this virus. If there is no data on the variety’s resistance to mosaic virus, then the planting material must be pickled in a 1% solution of potassium permanganate for 20 minutes.

Plants affected by mosaic are not treated , but are removed from the site and then destroyed.

Incorrect agricultural technology

Yellow spots on the leaves may also appear due to non-compliance with the rules for growing tomatoes. Usually these are the following reasons:

• high humidity;
• illiterate transplantation;
• mechanical damage to plant roots;
• lack of microelements and nutrients;

Let's take a closer look at these reasons below.

High humidity

If you grow tomatoes in rainy summers, in extremely humid conditions, or in an unventilated greenhouse with frequent watering, yellow spots on the leaves are likely to appear. Typically, the appearance of this symptom in such conditions is caused by a fungus and is treated with appropriate fungicides.

When watering, you need to make sure that drops of water do not fall on the leaves. Under the influence of sunlight, these drops will turn into a kind of lenses and lead to burns of the leaves and the appearance of spots.

Transplantation and root damage

These two reasons overlap with each other, since usually the roots are damaged during the transplanting process

To avoid this problem, when replanting it is necessary to handle the roots of the tomatoes very carefully, do not tear them off, and carefully place them in the hole

Nutritional deficiencies

If this is the reason, the tomato usually lacks zinc, copper, boron, molybdenum, sulfur or magnesium with nitrogen. To solve the problem, it is necessary to feed the plants, and in the future do not forget about the procedure for applying fertilizers.

A lack of all of these minerals causes spots of varying sizes and characteristics on tomato leaves. Let's get acquainted with the symptoms in order to know exactly which microelement the plants lack.

• Nitrogen - a lack of this mineral manifests itself as a uniform covering of all leaves with small yellowish spots.
• Copper - in this case, the bush does not become stained, but the greenery becomes noticeably paler and light green.
• Sulfur - the leaves noticeably turn yellow, becoming hard to the touch.
• Magnesium - the foliage is covered with small spots of a brownish-yellow hue.
• Manganese - yellowing of the leaves is accompanied in this case by subsequent rotting of the affected parts.
• Phosphorus - with a lack of this mineral, the top of the tomato bush turns yellow.

Sometimes yellow spots can also be caused by improper lighting of tomato bushes - often too intense, but sometimes by excessive shading.

Video on the topic:

Why did the leaves start to turn yellow?

Having observed this situation, experienced biologists have identified several factors. It’s not difficult to eliminate them, the main thing is to notice the problem in tomato seedlings as quickly as possible. We are talking about the following manifestations.

• Partial yellowing of several lower leaves.

This usually happens when transplanting tomatoes from small pots into boxes or soil. It's all about the root system. The plant, adapting to the new environment, increases its growth rate. New roots grow, but the leaves simply do not have time. To avoid yellowing on the first leaves, it is necessary to replant the plants in good soil in time.

• Yellow leaves with a blue tint.

This indicates that the plants have experienced a temperature change. Perhaps the tomato was damaged by frost - this is a common mistake of those who are in a hurry to plant seedlings in a greenhouse or greenhouse as quickly as possible. The color of the leaves changes again due to the root system, because everything in plants is interconnected. The normal food chain has been disrupted. Subsequently, the rate of growth and development of fruits changes.

• Sharp yellowing of the lower leaves of tomatoes.

There may be two reasons for this: the roots are crowded or the root system was damaged during loosening. There is nothing to worry about, the plants need to be created in comfortable conditions and given time to restore the root system.

• Dry soil.

The primitive lack of watering also manifests itself in the yellowness of the leaves. The movement of nutrients should occur from the lowest root. To achieve this effect, you need to water very abundantly, but as rarely as possible. Light spraying will not have an effect specifically for tomatoes.

• Micronutrient deficiency.

Depending on where the spots or spots appear, a deficiency of certain elements or minerals can be identified. Nitrogen deficiency causes medium-sized yellow spots throughout the tomato plant. Copper deficiency is expressed by the plant turning pale from the very bottom, but without specific spots. A lack of sulfur leads to yellowing and hardening of the leaves - it is easy to compare a healthy leaf and a hardened one by touch. Manganese deficiency affects the plant with sharp yellowing and rapid death. If only the top turns yellow and no spots appear, then there is definitely not enough phosphorus. There may also be an excess of it, expressed in the yellowness of the entire leaf area.

• Diseases.

More precisely, a fungal disease called fusarium. Externally, the disease is expressed by the yellowness of the leaves and their lethargy. It is very easy to identify: if watering is carried out according to the schedule, and the plants are in a clearly unhealthy state, corresponding to the symptoms of the disease, then this is fusarium. In the treatment, “Fitosporin” is used, which is used to treat the seedling up to 4 times every two weeks. With Fusarium wilt, the fungus attacks the roots of tomatoes very unexpectedly. The spores remain in the soil for a long time, and only manifest themselves when there is excess heat and moisture. Moreover, the plant externally shows the opposite signs: it looks like it is drying up, and has not been watered for several days. If the roots of tomatoes “catch” the infection, then this will definitely affect the yield. Sometimes the fungus is carried by untreated seeds. How does a fungal disease begin to manifest itself? First, the root system is disrupted, and then everything goes up the nutritional chain to the top. Peak of the disease - the plant does not absorb minerals. Tomato fruits on diseased stems are suspiciously small.

Fighting methods

What to do if spots appear on tomatoes? Since there are many problems that cause yellowing of tomato foliage, it is important to correctly identify the source of the problem and eliminate it. If the tops have turned yellow due to illness, you should not leave things to chance

Diseases are treated with chemicals and folk remedies.

Chemical and biological agents

Fungicides are effective against most tomato diseases.

The following drugs are used in treatment:

• "Abiga Peak";
• "Barrier";
• "Ordan";
• "Bravo";
• "Thanos";
• "Ditan";
• "Revus";
• "Quadris";
• "Consento";
• "Fitosporin";
• "Fundazol";
• copper sulfate;
• Bordeaux mixture.

Insecticides are used to control pests:

• "Iskra M2";
• "Confidor Extra";
• "Decis Profi".

Strengthen the root system with the help of growth stimulants:

• "Epin";
• "Heteroauxin";
• "Larixin";
• "Novosil";
• "Kornevin".

Correcting ground imbalance

As soon as it becomes clear which element is missing in the soil, it is necessary to feed it with special additives:

1. Phosphorus. The deficiency is eliminated with the help of “Superphosphate” - 15 g per 10 liters of water, the dosage is designed to treat 1 square meter. m.
2. Magnesium. Foliar treatments are carried out with magnesium nitrate - 5 g per 10 liters of water.
3. Potassium. Use potassium sulfate - 8-10 g per 10 liters of water. Treatment is carried out once every 4-5 days; after 3 procedures, a solution of the drug should be added to the soil - 15 g per 1 square meter. m.
4. Boron deficiency is corrected by spraying with a 1% boric acid solution. The procedure is carried out in the evening.
5. Iron. The bushes are sprayed with a 1% solution of copper sulfate or iron chelate. These products are suitable for foliar treatments.
6. Manganese. The seedlings are sprayed with a 1% solution of potassium permanganate.
7. Molybdenum. Plants should be treated with a solution of ammonium molybdate - 2 g per 10 liters of water.

Traditional methods

You can restore the nitrogen balance with urea - 1 tbsp. l. drug per 10 liters of water. The dosage is calculated for 1 square. m. Foliar treatments are also effective - 1 tsp. for 10 liters of water. During the procedure, the above-ground part of the plant is sprayed.

Organic fertilizers are also used to saturate the soil with nitrogen:

• mullein - 1 liter of fertilizer per 10 liter bucket of water;
• bird droppings - 500 g per 10 liters of water;
• wood ash or soot - 250 g per 10 liters of water.

Agrotechnical techniques

If there is excess moisture, stop watering for several days. To restore balance, add urea to the soil - 1 tsp. solution per 1 sq. m.

To prevent the plants from burning, an additional awning or canopy is installed on the garden bed for several weeks after planting. As soon as the seedlings take root, the cover can be removed.

When planting seedlings, keep a distance to prevent crowding. The distance between plants should be 70 cm.

If the leaves on the tomatoes begin to turn yellow due to lack of light, they cannot be replanted. It is better to thin out the tops by removing leaves that shade each other.

Restoring the root system takes a long time

During this period, it is important to provide the plant with sufficient nutrition and watering.

You can restore the balance of beneficial microelements with the help of additional fertilizing with “nitroammophoska” - 1 tsp. drug per 10 liters of water. Treatment is carried out once every 3-4 days in the evening until the yellowing of the leaves stops.

Why do tomato leaves wither and die?

Causes of drooping leaves:

• non-compliance with agricultural technology standards;
• diseases.

Yellowed leaves of tomato seedlings close-up.
Improper care of plants consists of:

1. dense planting;
2. unsuitable site;
3. insufficient, excessive amount of water;
4. incorrectly selected soil;
5. lack, excess of sunlight;
6. overheating, hypothermia;
7. in humid air;
8. drafts;
9. improper feeding.

When seedlings are planted densely, they shade each other. There is competition for sunlight. The bushes are stretching out. There isn't enough room for the roots. There is a struggle for water and nutrients. The result is a limp bush. Blackleg disease may occur.

The fungal disease fusarium causes wilting of tomato leaves. At the same time, the roots acquire a red color and the leaves turn yellow. Diseases can be defeated only at an early stage of development. If the bush can no longer be cured, it must be removed and burned. Cultivate the land.

When there is enough water in the plants, they are in a state of turgor. Deficiency causes them to wither. Excess moisture can lead to root rot and black leg.

Good lighting is necessary. Light is needed for photosynthesis. When planting seedlings early in a greenhouse, you can use additional lighting - fluorescent lamps. But you should not illuminate the plant during the day. Some processes in the plant take place only in the dark.

If the plants are in a greenhouse, the air temperature during the day should not be higher than 28°C, and at night – 18°C. Optimal – 24 – 26oC. At a temperature of 38–40°C, leaves begin to fall. Regular ventilation is required.

Tomatoes love warmth. Cold weather can cause drooping leaves. At temperatures below 15o C they do not absorb phosphorus, at 10o C they do not absorb nitrogen. Feeding the bushes should be balanced.

Prevention of tomato diseases

Perhaps, we have considered all the most likely causes of spots on tomato leaves. It also became clear what to put into the sprayer. It remains to clarify one more point. What should we do for prevention? How to prevent pathogens from reaching your garden beds?

By and large, you won’t find anything special in the list of preventive measures. Everything is familiar, a lot is already being done, something is being planned. So, to reduce the risk of tomato infection, we need:

• 1. Select disease-resistant varieties and hybrids. This is especially true for viral and bacterial infections;

2. Treat the seeds before planting. The biofungicide Planriz has proven itself well as a disinfectant. Dissolve 1 milliliter of Planriz per liter of water and soak the seeds for about 6 hours;

3. Maintain crop rotation. Do not plant tomatoes in the same bed year after year. It is difficult to adhere to this rule in a greenhouse, so after harvesting, be sure to plant green manure. For example, mustard or calendula;

4. Do not thicken the plantings and regularly ventilate the greenhouses. Still, most pathogens actively develop at high humidity;

5. Do not overdo it with watering. Read about how to properly water tomatoes HERE;

6. Carry out preventive treatment of plants with folk remedies, biological products, and, in case of high probability of damage, with chemical fungicides;

7. Break off the lower leaves. By the beginning of August, it is enough to leave 3-4 top leaves on each bush;

8. Remove suspicious leaves. If you notice an incomprehensible speck, carefully tear off the leaf and take it away from the greenhouse or tomato bed;

9. Remove tops from the beds. Let it rot in compost;

10. Treat greenhouses. The method of fumigating greenhouses works perfectly when a piece of wet woolen cloth is thrown into a bucket of hot coals and the greenhouse is kept closed for a day.

In conclusion, we would like to add that in rare cases, spots on tomato leaves can be caused by a lack of nutrients. We have a large TABLE with photos and descriptions of symptoms of deficiency of a particular substance.

Feed your tomatoes in a timely manner, inspect the tops and remember that for every disease there is a treatment.

We wish you success and great harvests!

Spots on tomatoes - diagnosis

For your convenience, we have compiled a table for diagnosing problems with tomatoes by leaf color. You can immediately go to this table with photos of the most common spots on tomato leaves to make it more convenient for you to determine the cause of the problem and determine countermeasures. For a more detailed description of possible tomato diseases or other problems associated with disruption of the supply of nutrients to the tomato bush, read on.

Bronze angular spots, rings or circles

How it manifests itself:

The change in color of the leaf blade, mentioned above, is the first symptom of the disease. Subsequently, angular spots, circles or bronze-colored rings form on the leaves. Then they turn brown. Large concentric pale brown spots appear on green fruits. As the tomatoes ripen, these spots turn yellow.

Conditions for active development:

Most often, the virus affects open ground tomatoes. The infection is carried by harmful insects, namely thrips. The greater the number of pests, the more actively the disease spreads.

What to spray:

The fight against spotted wilt virus comes down to the destruction of insect vectors. Insecticides like Aktara, Confidor, etc. are used against thrips.

Depressed brown spots

Did the top leaves suddenly wilt? And then depressed round spots of a black-brown hue appeared on them? This is how anthracnose announces itself - another tomato disease caused by a fungus.

How it manifests itself:

Anthracnose affects adult fruit-bearing plants. The spots first appear on the leaves, but then spread to the fruits. A hollow on a tomato is a characteristic sign of the disease. Depressed spots can appear not only on growing fruits, but also on those that are removed from the bush and ripen at home.

Conditions for active development:

Extremely high air humidity (90%) and drops of water on plants create a favorable environment for the pathogen anthracnose.

What to spray:

To control the disease, drugs containing sulfur are used. For example, Thiovit Jet or Cumulus-DF. In addition, copper-containing agents are traditionally used against fungi. For example, Oxychom, Hom or 1% Bordeaux mixture. Among the antifungal drugs, it is also worth noting Bravo, Ditan, Flint, Polyram.

Gray-white spots with a dark rim

How it manifests itself:

Initially, the fungus affects old leaves in the lower part of the bush: many watery, barely noticeable spots appear. Then they lighten and a red-brown halo forms around them, which later turns black. Near the spots, the leaf surface turns yellow. Over time, the leaves dry out and fall off.

Conditions for active development:

Septoria is a disease of mid-summer, as it develops rapidly at high air humidity (90-95%) and high temperatures (+20°C-25°C). True, neither a decrease in humidity nor a cold snap will affect the activity of the pathogen. This is why it is dangerous - its survivability.

What to spray:

For preventive purposes or when planting seedlings in open ground, treatments with biofungicides are effective. For example, Alirin or Fitosporin. As for “chemicals,” we recommend spraying plants with Revus, Bordeaux mixture, Oksikhom or Hom.

Small dark round spots with a yellow border

When many dark brown spots with a yellow halo are visible on the leaves of tomatoes, our enemy is Phoma. In other words, Phoma rot. Its causative agent is a fungus that lives in the soil, the remains of tops or on the tomato’s neighbors in the greenhouse - on peppers.

How it manifests itself:

Over time, the spots form concentric rings, grow and become covered with a black coating of spores. The most unpleasant thing is that Phoma affects the fruits. A rotten spot appears at the stalk. Gradually, rot “devours” the tomato from the inside. What kind of harvest are we talking about here?

Conditions for active development:

Phoma rot loves high air humidity and a large amount of nitrogen in plant tissues. So don’t get carried away with nitrogen fertilizing!

What to spray:

Chemicals: Hom, Oxychom, Bordeaux mixture. In addition to treatments, do not forget to pick off and remove diseased fruits and leaves away from the beds.

What to do if the lower leaves of tomatoes turn yellow

Yellowing of the lower leaves is less dangerous than yellowing of the upper ones, since it does not always indicate a disease of the plant. Most often, the plant gets rid of older leaves in order to direct all its resources to the development of fruits.

Yellowing of the lower leaves does not always indicate a serious problem

In order for tomatoes to feel good, you must follow the recommendations we gave above:

1. Water the plants regularly but moderately.

2. Avoid hypothermia.

3. Conduct complex fertilizing in a timely manner.

4. Fight diseases and pests.

5. Replenish the deficiency of elements. For example, yellowing of the first two pairs of true leaves, which is accompanied by their curling upward, may indicate a lack of molybdenum. In this case, yellowness first appears in the form of small spots, and then covers the entire surface of the leaf. The leaf veins remain green. In this case, it is necessary to treat the tomatoes with a solution of ammonium molybdate (2 g per 10 liters of water).

The yellowed lower leaves will sooner or later dry out and fall off on their own, but it is better to remove them yourself so that the plants do not waste nutrients on them.

To avoid damaging the skin on the tomato stem, remove the leaves carefully.

To do this, lower them down, press them against the stem and only then carefully pull them up

Answers to frequently asked questions

The leaves of the seedlings have turned yellow, what should I do?

Determine the cause of the problem? Most likely it's due to improper care. This is much more common than diseases and pests.

Will the seedlings survive?

It all depends on the severity of the problem and what caused the yellowing. Lack of nitrogen and drought are easily corrected, but overwatering and fungal infection are serious problems.

Is it possible to plant yellow seedlings in the garden?

If they are not sick with fungal diseases, then it is possible. It is likely that they will take root and produce a harvest.

Other causes of yellow spots

The author of the video shows another reason for the appearance of yellow spots on the leaves. They appear after a hailstorm.

Errors in agricultural technology

In addition to diseases, the cause of yellow spots that appear can be considered to be improper care of plants and mistakes in their agricultural technology made by vegetable growers themselves.

Sunburn

The appearance of yellow spots on the leaves of tomato seedlings and adult plants can be caused by improper lighting of young and adult plants. This is usually explained by the fact that it is too intense, but damage can also occur from a lack of it.

Sunburn can also cause your tomatoes to develop spots. Their color can range from white to light yellow and they form on hot days, with strong insolation. They often form in places where drops of water fell when watering plants during the day, and on tomato seedlings - because they were unprepared in the sun. The intensity of the spots can vary: from rare, single specks to completely covering the entire surface of the leaves. In their place, the tissue is so damaged that it dies (necrosis), so burns are very dangerous.

You can avoid their appearance if you grow tomato seedlings in the brightest place in the room - on the windowsill. After planting it in a greenhouse, for the first few days you need to cover the bushes from the sun with a covering material, such as lutrasil.

You cannot water tomatoes during the day, when the intensity of the rays is maximum; it is better to do this only in the evenings or early in the morning. You also need to water the plants at the roots, and not sprinkle them on the leaves. If burns have already appeared, then the tomatoes need to be sprayed with Epin, which will help the plants recover from damage.

High humidity

In greenhouses, tomatoes become covered with yellow spots in conditions of high humidity if the room is not ventilated for a long time or the tomatoes are watered too often. Usually the cause of yellowing is fungal diseases, for which humidity is an ideal condition for development.

When yellow spots appear, you need to adjust the volume of water poured under the plants and the frequency of watering

It is important to remember that tomatoes require abundant but relatively infrequent watering (about 2 times a week). In this case, it is necessary to ensure that droplets of moisture do not fall on the surface of the leaves, where they turn into peculiar lenses that provoke burns.

Malnutrition

The color of tomato foliage depends on what nutrients enter the plant from the soil. Often, a deficiency of certain elements leads to the formation of yellow spots. For example, if there is enough organic matter in the soil, but little copper, then the lower leaves of tomatoes begin to turn yellow, they become pale, light green in color. If there is a lack of manganese, this is manifested by the blanching of the lower leaves and the fact that the young leaves of adult bushes grow small and spotty.

Iron deficiency is manifested by the fact that the leaves begin to quickly turn yellow and disappear, and nitrogen deficiency – by the appearance of yellow-green spots on them, distributed evenly over the surface of the plates. Insufficient magnesium content can be determined by the fact that not only yellow, but also dark red or brown pigmentation appears on the leaves, and they themselves curl upward. The problem of deficiency of nutrients in the soil can be solved by regularly feeding tomatoes with fertilizers in which they are contained.

Other reasons

A tomato may become covered with yellow leaves not only due to diseases. A common cause is root damage. Mechanical damage is caused by careless loosening of the soil near the tomato. The leaves of the lower tier begin to turn yellow.

The root system of tomatoes has good recovery, so this goes away on its own. It is recommended to add organic fertilizer to the soil near the plant.

Another reason is poor-quality fertilizer or its shortage. Any plant, including tomatoes, change their color if they lack copper, iron, manganese or sulfur. Yellowing of greenery may indicate nitrogen starvation. As a result of a lack of magnesium, the tomato will become covered with yellow pigments.

Yellowing of leaves on seedlings

The leaves of young plants may begin to turn yellow due to natural reasons. Transplanting seedlings from pots to garden beds is stressful for the plants. Yellowness on the leaves indicates the adaptation of tomatoes to new conditions. This happens due to a temporary failure in the supply of nutrients from the root system to the tops. To maintain viability, the plant rejects the lower leaves.

If the problem is caused by planting stress, only the lower leaves will be affected by the color changes. After a few days, the leaves should fall off; if this does not happen, they are removed manually.

Other reasons for yellowing seedlings:

• small container;
• watering errors;
• hypothermia;
• nitrogen deficiency;
• insufficient lighting;
• soil acidification.