Why do tomato leaves turn white and how to avoid it

What causes the leaves of tomatoes in open ground to turn yellow?

Basically, yellow spots on the leaves of tomatoes grown in open ground appear for the same reasons as when grown under cover. However, there are also some nuances.

1. Low air temperature. This problem is practically unknown to greenhouse tomatoes, but “outdoor” tomatoes can get hypothermia during cold weather, which results in yellowing of the leaves.

2. Damage by diseases and pests. Fusarium, as well as other tomato diseases, can lead to yellowing of the plant's leaves. In addition, this problem may indicate that the plant's roots are infested with pests.

3. Lack of watering. If the weather outside is hot, dry, and the tomatoes do not receive the required amount of moisture, their leaves begin to turn yellow.

4. Excess moisture. Excessive watering is also dangerous and can cause yellow spots to appear on tomato leaves.

5. Deficiency of elements and minerals in the soil. Lack of nutrients, especially nitrogen and potassium, can also cause yellowing. To return the green color to tomato leaves, you need to feed them with complex fertilizer.

6. Damage to roots. If you break the roots of tomato seedlings when planting or damage them when weeding or loosening, the leaves may turn yellow for a short time. As soon as new roots form on the plant, the green color will return.

Classification

Tomato varieties are divided according to the following characteristics:

• Type of use: production, juices, canning, canteens, etc.
• Fruit ripening period: early, mid-ripening, late.
• Growth form: determinate (short), indeterminate (tall).

Tomato is a heat-loving crop. The optimal temperature for development is +23-25 ​​degrees; the plant cannot withstand even short-term frosts. At a temperature of −10, pollen will not appear.

The soil for tomatoes should be fertile and loose, saturated with nitrogen, iron, and potassium. They are very demanding of light, so seedlings are often grown under bright fluorescent lamps.

Tomato seedlings

White spots on tomato leaves: what is it and how to treat

Many gardeners are faced with a situation where they carefully looked after tomato seedlings, monitored their development and eagerly awaited the harvest, and at a certain moment discovered white spots on the leaves of the tomato. Their appearance usually causes alarm and makes the gardener fear for the harvest.

Sometimes such spots are actually symptoms of viral infections or fungal diseases, in which case the seedlings require urgent treatment. However, in some cases, stains may only indicate improper care. However, even in this case, urgent intervention by the gardener is required to save the crop.

Causes of white spots

In this article we will talk about several reasons for the appearance of white spots on tomato seedlings, as well as ways to eliminate them. By following the recommendations given, you will prevent the development of the damaging factor and save your harvest.

Septoria

Dull white spots with a dark border may appear on the lower leaves of the tomato. Visually, they appear to be covered with a gray coating. This symptom is a sign of a fungal disease, which is popularly called white spotting. However, this disease has a scientific name - septoria.

If you start this disease and do not fight it, black dots will appear in the middle of the white spots. After this, the foliage darkens and falls, and the disease spreads to the stem, petioles or fruits of the tomato.

Infection with this fungal disease most often occurs through the soil, but in some cases the cause lies in improper seed treatment. Seeds that are not treated before planting run a significant risk of contracting septoria in the future.

High air temperatures coupled with high soil moisture significantly contribute to the development of this disease. For this reason, the rapid development of white spotting occurs in July.

Affected seedlings are also treated with Fitosporin

It is important to follow the instructions written on the manufacturer’s packaging and observe the recommended concentrations of the solution.

Mosaic

A viral infection that affects tomatoes. For this disease, it does not matter where the tomato grows - in open ground or in a greenhouse. In both cases, plants are equally at risk of developing this disease. Infection most often occurs through seed material. In rare cases - through the sap of seedlings during picking.

During the development of the mosaic, the tomato foliage becomes covered not only with white, but also with dark and light green spots. The foliage takes on a mosaic-like color.

Unfortunately, there is no effective method that will help rid affected plants of this disease. The only thing a gardener can do to save the harvest is to completely pull out and throw away the infected plant so that neighboring plants do not catch the disease. As a preventative measure, the area can be treated with a solution of potassium permanganate.

To reduce the risk of contracting this disease, you should purchase seeds only from high-quality, trusted manufacturers, and also carefully process them before planting.

Lack of microelements

For tomato seedlings, proper care is very important, which must necessarily include fertilizing. Incorrectly selected fertilizer can negatively affect the health of the plant and the quality of the crop. Sometimes white spots on foliage may appear precisely for this reason.

In order to determine what elements the plant lacks, it is worth looking at which leaves have light spots. If spots appear on the lower leaves, the tomato lacks the following substances:

• molybdenum;
• magnesium;
• zinc;
• potassium;
• phosphorus;
• nitrogen.

Spots on young leaves located on top indicate a lack of the following substances:

• manganese;
• chlorine;
• gland;
• sulfur;
• boron;
• calcium.

Preventive measures

Any tomato disease is easier to prevent than to cure, so you need to pay attention to preventing the occurrence of white spots on these fruits.

Important! To determine the exact cause of white spots on tomato leaves, you need to analyze all the growing conditions of the plants.

Basic preventive measures are described below:

1. Hardening off tomato seedlings before transplanting into a greenhouse.
2. Ensure adequate watering of plants, especially in hot weather.
3. Ventilate the greenhouse after watering to reduce humidity.
4. Application of fertilizers containing potassium, nitrogen and boron.
5. Thorough cleaning of last year's seeds and plant debris.
6. Disinfecting the soil before planting tomato seedlings.
7. The location of the greenhouse with tomatoes is away from the potato beds.
8. Enough free space around each tomato bush in the greenhouse.

If tomatoes are grown incorrectly in greenhouse conditions, there is a high probability of diseases that can destroy the entire crop. To prevent this from happening, it is enough to maintain comfortable conditions for plants in the greenhouse and promptly begin treatment of tomato bushes when the first symptoms of diseases appear.

Why do tomato seedlings turn yellow on the windowsill?

Many summer residents grow seedlings on window sills and loggias, starting in winter, in order to get strong and strong plants as the weather warms up. Unfortunately, conditions are not always suitable for obtaining full-fledged healthy seedlings. It all depends on several factors:

• location of windows relative to cardinal directions;
• window and sill dimensions;
• the presence of additional light sources;
• soil quality;
• timely watering and fertilizing;
• drainage.

Growing plants at home is a labor-intensive process that requires skills and some effort. Sowing seeds for picking is carried out in containers quite densely. Excessive planting density can cause yellowing. There is not enough space for the root system; some seedlings oppress others. In this case, they try to remove weaker shoots, giving the opportunity for strong ones to develop.

After diving into separate cups or pots, the roots are partially damaged; in such cases, the tomatoes recover quite quickly with proper care, strengthening the roots. Additional fertilizing in this situation will ensure an increase in green mass in 5-10 days. The plant visually looks stronger, the color becomes intense green.

The most common disease of home-grown tomatoes is fusarium. The leaves turn yellow and fall off over time. At the first signs, seedlings are sprayed with the drug “Fitosporin” and its analogues.

For full development, additional light sources are installed on the windows, extending daylight hours to 5-6 hours.

It is imperative to control the humidity level in containers and regularly loosen the soil. Ventilate the room at any time of the year. Seedlings must be placed in such a way that the plants have enough space to grow. Provide air access and a good drainage layer so that the water does not stagnate after watering.

Why do tomato leaves turn white and how to avoid it

Tomatoes are one of the most popular and sought-after crops in our country, therefore they are actively grown both in open ground and in greenhouses. Failure to comply with cultivation technology, as well as unfavorable external factors, often cause various painful conditions of garden plants, including the appearance of white leaves on tomato bushes.

Brown spot on tomatoes (video)

You should adhere to the following rules for growing tomatoes in home gardening:

It is necessary to plant exclusively healthy plants that are not affected by diseases or pests; Watering should be carried out with warm water, directly at the base of the garden crop; Irrigation activities should be carried out in the morning, which will allow the tomato foliage to dry well; it is very important to promptly remove and destroy all affected plants; it is mandatory to follow the rules of crop rotation; good results are obtained by treating the above-ground part of a tomato bush damaged by the sun with a solution based on the drug “Epin”.

Systematic inspections of tomato bushes make it possible to detect the problem in a timely manner and develop an effective treatment plan.

To enhance growth processes, as well as to increase the resistance of garden crops to temperature and water stress situations, including heat and drought, it is recommended to treat with the drug “Verva”, diluted at the rate of 2.5 ml per 3 liters of water. Spraying of the aboveground part is carried out in several stages, at the flowering stage of each cluster. The average consumption of the working solution is approximately 300 ml for every 10 square meters. m of landing area.

Tomato diseases (video)

Thanks to such treatments, plants grow stronger and are able to actively resist all adverse external influences.

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Tomato leaves turned white after planting, what to do?

High-quality, strong tomato seedlings planted in the ground sometimes make you worry. Its green, elastic leaves can turn white immediately after planting, without changing turgor. What is it - a disease, a problem with nutrition or soil? The reason is completely different.

Reasons for whitening of tomato leaves

Tomato seedlings are usually grown indoors: stable air temperature, absence of precipitation and wind, contribute to the fact that the seedlings grow together, become stronger, and grow green leaves. The only disadvantage of growing seedlings at home is the lack of lighting, which is usually compensated for by artificial light lamps.

In such favorable conditions, seedlings grow of high quality, but tender. She was not used to changeable weather, sharp temperature fluctuations, bright ultraviolet rays, or cold spring precipitation.

Having planted seedlings outdoors, after a few days you can see that the upper leaves have changed color - they have become completely white. If in adult plants the cause may be a disease, attack by pests or a lack of microelements in the soil, then in seedlings this happens for a completely different reason.

Tender plants transplanted into the ground experience stress. It manifests itself in a change in the color of the leaves from green to white, while the whiteness appears evenly, without spots or dots. After some time, these leaves may fall off.

Main Causes of Stress

• bright sun rays;
• sudden changes in day and night temperatures;
• cold ground;
• cool rains;
• strong gusts of wind.

For tomatoes planted in a greenhouse, the main cause is bright sunlight.

What to do if the leaves of tomatoes turn white

Leaves that turn white may fall off over time. You shouldn’t be afraid of this, because the growing point is the top of the plant. New green foliage will emerge from it.

To avoid this problem, after planting, it is advisable to cover the seedlings with agrofibre. Low density non-woven covering material is suitable. To prevent the seedlings from breaking, you need to install arches over the bed that will prevent the shelter from sagging.

To protect young plants from the bright sun, you can use the old proven method. Branches are broken from birch, aspen, or other trees with large foliage. They are stuck into the ground near the tomatoes on the sunny side. A light shadow is formed. After a few days, the leaves on the branches dry out, and during this time the seedlings adapt to the bright sun.

What to spray

To boost the immunity of tomatoes and make it easier to adapt to new conditions, it is recommended to spray with a solution of “Epin” or “Zircon”. The solution is prepared at the rate of 1 ml of the drug per 5 liters of water.

The treatment is carried out one day after planting, spraying the leaves in the morning or in the late afternoon.

If, according to the weather forecast, cold weather is expected on the days chosen for planting seedlings, then it is better to postpone it to a warmer time. The less stress the seedlings experience, the faster they take root in a new place and begin to grow.

The leaves of tomato seedlings may also turn white if part of the roots are damaged during replanting. This shock can be eliminated if you grow seedlings in separate cups. The transplant is carried out together with a lump of earth, which contributes to better survival in the new place.

Prevention

You can prevent the leaves of tomato seedlings from turning white. To do this you need:

• pick up tomato seedlings into separate containers;
• a week before planting, spray with a solution of microelements;
• prepare agrofibre to shelter seedlings from the bright sun and night coolness;
• two weeks before transplantation, carry out hardening;
• choose a day for planting, following the weather forecast;
• one day after planting, spray with Epin, Zircon or other growth stimulants.

Hardening is carried out in stages

This is especially important for tomatoes that grew under artificial light lamps. In the first days, plants are taken out only for a few hours, avoiding sunlight

After a week, the boxes with seedlings are left overnight, covered with thin insulation. You can cover it overnight until transplantation, it depends on the weather.

A week after the start of hardening, they are accustomed to the sun. First, the plants are left in diffuse sunlight, then placed in bright light for two hours. The time is increased by 2-3 hours daily.

The full hardening cycle lasts two weeks.

Why do the leaves of tomato seedlings turn yellow?

Yellowing and signs of wilting, accompanied by spots on the surface of the leaves, may be due to insufficient light. Tomatoes do not tolerate shade well; they must be grown in the sun or use artificial lighting.

The leaves of tomato seedlings turn yellow when the soil is waterlogged. The roots rot and bacteria and fungi form on them. In this case, a certain procedure must be carried out, otherwise the plants will die:

1. The seedlings are carefully removed from the ground, trying not to damage the root system.
2. The roots are inspected, damaged ones are removed, and washed in clean water.
3. Carefully planted in pre-prepared soil with mineral fertilizers.
4. The earth is slightly moistened.

Advice! To prevent and strengthen plants, we recommend adding a weak solution of potassium permanganate to settled warm water when watering.

It is necessary to regularly ventilate the room, regardless of the time of year. Fresh air will not allow bacteria to multiply and become paralytic. If the upper leaves of a tomato turn yellow, this means a deviation from the norm and a lack of microelements in the soil necessary for full growth.

1. Calcium deficiency is characterized by the appearance of yellow spots on adult leaves, the size of which increases hypertrophically. In this case, liming or adding calcium nitrate (20 g per bucket of water) is practiced.
2. Iron deficiency is determined by the yellowing of the central part, and the edges of the leaves remain with green veins. Plants are sprayed with iron sulfate or iron chelate. The same composition is watered directly under the root of the seedlings. The result will be noticeable after the first day.
3. Leaves lighten, veins become red, and stems become brittle when there is insufficient sulfur. Tomatoes are sprayed with magnesium sulfate (10 g per bucket of water).
4. Boron deficiency does not appear immediately; yellowing begins gradually. The veins darken, leaves and stems become brittle, and fruits do not set.
5. With a lack of manganese, the veins remain green, only the spaces between them turn yellow. The first signs are noticeable first on the upper leaves, later the lower leaves turn yellow. Spraying is carried out with a weak solution of potassium permanganate or manganese sulfate (5 g per bucket of water).

To prevent such symptoms and prevent diseases, comprehensive plant feeding is carried out regularly throughout the growing season.

Follow preventive measures

Whitish leaves are a sign of disease, so plants require urgent treatment.
It is much easier to prevent any problem than to solve it:

1. Treat seeds before sowing. This makes it possible to destroy all pathogens that often overwinter on the seed coat. Use a solution of potassium permanganate, hydrogen peroxide or any specialized product for work.
2. Provide plants with all necessary microelements. Fertilizers should be applied within 2 weeks after germination. In this case, it is most convenient to use complex preparations, which contain everything that is needed for tomato seedlings.
3. Observe the norms and frequency of watering. Lack of moisture causes foliage to dry out and weaken plant immunity. And an excess causes infection with fungal diseases that affect the leaves.
4. Be sure to pick the tomatoes into separate containers. The plant needs a lot of space for normal development and growth. Thickened plantings significantly increase the likelihood of contracting diseases and reduce plant immunity; seedlings grow thin and weak.

The leaves may turn white either completely or partially, it all depends on what problem has affected the plant.

1. Harden off seedlings before planting in the ground. Start work 2 weeks in advance, at first keep the plants outdoors for a short time, but increase the period every day. Also gradually accustom tomatoes to the sun so that they do not get burned.
2. Protect plants during hot periods. After planting tomatoes in the ground, the easiest way is to cover them with agricultural cloth during the hottest hours of the day. As for the greenhouse, it can also be covered with agro-canvas or the structure can be whitewashed from the outside, then the whitewash can be easily washed off with water from a hose.
3. Plant on cloudy days. It is best to choose a period when there is no bright sun and the weather is warm, calm. In such conditions, plants adapt quickly.
4. Provide tomatoes with essential microelements. Lack of nutrition significantly reduces resistance to pests, diseases and adverse weather conditions.
5. Carry out preventive treatments against diseases. Most often they are done in the spring and increase resistance to infection for the entire growing season.

Fungal diseases always begin with small lesions on the leaves, but if nothing is done, then very soon the entire surface will be affected

The author of the video creates gentle conditions for plants in case of minor leaf lesions. Place them in partial shade and periodically loosen the soil to improve air exchange.

How to treat seedlings

If you do not take urgent and adequate measures to correct the current situation, the tomatoes may die. First of all, you should try to adapt the sluggish yellowed seedlings, for which:

• spray with phosphate fertilizer (weak solution);
• feed constantly until new leaves grow and the plant is completely restored, saturated with nutrients (nitrate, chloride, phosphate);
• treat the root system with a store-bought stimulant to form new roots.

Note! Experts advise feeding tomatoes with complex fertilizers. Using traditional methods, you can prepare a stock solution of chicken droppings and water the beds. If a stimulant is used, then treatments must be carried out strictly according to the instructions.

If a stimulant is used, then treatments must be carried out strictly according to the instructions.

Basic methods for eliminating errors if tomatoes turn yellow after planting in a greenhouse:

If the lower leaves of a row and the stem of seedlings turn yellow due to damage to the root system or careless loosening of the soil, then use Kornevin for watering. To resuscitate the roots, you can spray tomato bushes with complex fertilizer

Drying and yellowing of leaves due to overheating of seedlings or sudden temperature changes (which often happens during the day and at night in greenhouses, when the leaves begin to turn yellow and dry, lose their elasticity, and the root system weakens) - it is necessary to stabilize the temperature in the greenhouse, place a barrel next to the seedlings with water

So the water will heat up during the daytime and absorb heat, and give it back at night

High acidity and heavy soil harm seedlings. When yellowness appears, you should pay attention to the soil. Before planting tomatoes in the greenhouse, prepare a mixture of peat, garden soil, sifted river sand and ash. Till the soil, dig

If it is noticed that the soil begins to sour and the water begins to stagnate, then the situation can be prevented if after each watering you loosen the soil, thus normalizing the acidity level. If the leaves turn yellow due to a lack of nitrogen, it is worth fermenting the soil with fermented mullein. Prepare a solution: water (20 l.), mullein (1 l.) or spray the bushes with a solution of potassium permanganate containing warm water (10 l.), manganese (1 tbsp.).

Tomato leaves acquire a marbled color due to a lack of iron in the soil. You can make up for the deficiency by adding manure solution and ash (1*10). Experts also recommend taking forest soil, for example, collected near a maple tree, for planting tomatoes in polycarbonate greenhouses. It is this kind of soil that will become balanced and nutritious for tomatoes.

Diseases and pests

Often the tender, juicy roots of tomatoes are attacked by harmful insects:

• the mole cricket, which prefers to feed on organic matter and build nests, causing yellowing of the leaves;
• The wireworm begins to lay larvae on the roots of the tomatoes or nearby, eat the succulent roots, making their way to the stems, as a result of which the leaves begin to lighten, and the bushes may eventually die completely.

In the fight against mole crickets, we use special preparations (Thunder, Medvedka), preparing a solution and pouring it directly into the holes made. Can be used:

• infusion of hot pepper (150 g per 10 liters of water);
• vinegar solution (2 cups of regular vinegar per 1 bucket of water);
• pink solution of potassium permanganate for soil disinfection.

In the fight against wireworms, a composition of sand, sawdust, and the purchased drug Bazudin will be used: mix the ingredients and sprinkle around the plantings.

If the beetle has already been noticed at your summer cottage before, then before planting tomatoes in the greenhouse, you should immediately treat the soil in advance. Why, 3-4 days before transplanting the seedlings, bury small pieces of vegetables strung on steel or sticks, up to 2-7 cm long. Dig into the ground so that the tips peek out. The beetles will begin to climb on them. After 2-3 days, it will be easy to collect the accumulations of insects with your hands and burn them.

A particular danger to the root system of tomatoes is a pathogenic fungus that causes late blight, fusarium and yellowing of leaves.

Important! Pathogenic fungi are contagious. If they live in the soil, they can easily get into tomato seeds from contaminated soil or from garden tools, causing the leaves to turn yellow in the future.

Methods for controlling fungal diseases in tomatoes:

• Mole cricket and wireworm feeding on the root system. The following drugs will help eliminate it: Bazudin, Medvetox. If nematodes appear in the greenhouse, it is recommended to replace all the soil completely.
• Brown spots on leaves and fruits are the result of frequent watering. To correct the situation, you need to start watering the tomatoes moderately and at the root so that droplets of water do not fall on the leaves.
• Yellowing of bushes and leaves from late blight is treated with Bordeaux mixture. To prepare the solution: vitriol (100 g), slaked lime (150 g) and pour water (10 l). Spray, pouring 2 liters. solution per 1m2 plot.
• For fusarium, which affects seedlings and adult plants, it is necessary to spray with the following preparations: Trichodermin, Previkur, Energy.

Note! If no pests are observed in the greenhouse, the root system is intact, but the leaves still turn yellow, then it is likely that infection with fusarium or late blight has occurred. To prevent late blight, you can water each bush with a solution of potassium permanganate (pink), Bordeaux mixture, or special preparations (Hom, Fitosporin)

The reasons are different if the leaves of tomato seedlings turn yellow, but what to do in the greenhouse? It often happens that it is enough to take a closer look, find out the problem quickly and take corrective measures. The main thing is not to leave yellowness and wilting unattended. Otherwise, you may not receive enough harvest or plants due to soil contamination; failure to comply with agrotechnical requirements may soon wither and die completely.

When caring for seedlings, it is important to ensure regular watering and loosening of the soil. Tomatoes are a capricious crop, but if you create normal greenhouse conditions for growth and vegetation and then in open ground, then after establishment they will begin to grow stocky and strong, will not stretch out much, and will be able to independently fight insect pests and fungal diseases

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Why do the leaves of tomatoes in a greenhouse turn white?

Today, tomatoes are one of the most popular products that are always found on the table.

Only sometimes it is quite difficult to grow them even in a greenhouse, since there are times when white spots may appear on the strongest and healthiest bushes.

And not many gardeners know what causes this and how to deal with it. White leaves on tomatoes in a greenhouse - what could be causing this?

Reasons for the appearance of white leaves on tomatoes in a greenhouse

Causes of white spots

Even though tomatoes are an “easy” crop, sometimes problems can arise with them, especially if they are grown in a greenhouse, although a greenhouse is a one hundred percent guarantee that the crop should definitely grow.

But sometimes, due to the fact that there may be temperature changes and poor ventilation in the greenhouse, a number of problems may appear. Most often this happens due to the fact that they are exposed to the sun's rays, and were not previously prepared for this.

Tomatoes have very tender leaves.

If these are sunburns, they usually only affect the upper leaves of the plant. In addition, this can happen due to the fact that the seedlings were not previously prepared for planting in the ground.

If this is not possible, then you can put them on the windowsill, where you can leave them for the whole day.

If you have not done this, then it is best to immediately cover them for the first time when planting, so that the sun does not hit the plant. During the first 11-15 days, the bushes will get used to the soil, and it is possible that they may not like it and then white mold may appear as a “protest” to the soil.

Tomato diseases

The most common diseases with white spots on tomatoes:

• a disease such as septoria;
• white spotting in tomatoes;
• a large lack of many minerals, and as a result the appearance of plaque.

The last problem occurs due to the fact that tomatoes are planted in the same place every year, and at the same time, without giving the required amount of fertilizer, and then the earth takes all the minerals for itself, is completely depleted and, as a result, the plants do not receive vitamins and get sick . Tomatoes do not have a strong immune system at first.

Prevention of white spots

In order to prevent trouble, you can take the advice of experienced breeders and carry out preventive maintenance of tomatoes.

1. An excellent preventive measure would be pre-treatment of all planting seeds.
2. If spotting is noticed on seedlings, it is necessary to remove the damaged bushes from the area.
3. Preventive treatment must be carried out with products that contain large amounts of sulfur.

The seedlings have turned white, how to save them???The leaves of the seedlings are turning white. What to do. SHOCK. TOMATO SEEDLINGS PURPLE. WHAT TO DO?

It is recommended to plant only resistant tomato varieties that are less susceptible to diseases.

Conclusion

In fact, there are quite a few reasons why greenhouse tomatoes may develop white spots. The most important thing to remember is that all plants must be prepared by sunbathing before planting, and the second fact is that moisture and temperature must be constantly monitored.

Ventilate the greenhouse once a day for several hours, and then you should not have any problems. When plaque appears, change the seedlings and remove the leaves. And as soon as a white coating appears on the tomatoes, spray them with the appropriate preparation.

Powdery mildew

This disease first affects the leaves of the plant - they become stained, wither and fall off.

New leaf plates may grow in place of dormant buds, but they will no longer become full-fledged.

Powdery mildew is caused by fungal spores of the following species: Leveilluia taurica and Oidiopsis sicula.

Reasons for appearance

The fungus appears for several reasons:

• increased air humidity (more than 75%) at high temperatures (20 degrees and above);
• high levels of nitrogen content in the soil;
• densely planted seedlings;
• non-compliance with soil moisture regime.

The fungus can also be transmitted from an affected plant to a healthy one.

This happens in the following ways:

1. by air;
2. through water (splashes of water that break off when watering infected seedlings);
3. the gardener himself transmits the fungus by touching a diseased sprout and then touching a healthy one;
4. through parasitic insects.

Signs

Powdery mildew begins to attack the plant from the outside of the leaves. First, a slight pigmentation of small white dots appears (sometimes with a green or yellow tint). Gradually, the spots become larger and cover the entire surface of the leaf. As the disease progresses, the spots become whiter and denser - in the overall picture, the bush looks as if it had been doused with lime.

If you look closely, you can see that the pigmentation is covered with a tiny coating - this is the mycelium of the fungus.

Sometimes gardeners confuse powdery mildew with white spot. It is worth noting that the second disease develops from the inside of the leaf; first discolored and then reddish spots appear on its surface.

How does it develop and why is it dangerous?

Powdery mildew develops very quickly. At first, the fungus affects only small areas of the leaf blades. If no action is taken, the disease will spread to all leaves and cause them to fall off. However, often the affected leaves do not fall off. This is explained by the fact that powdery mildew lives on the plant as long as it shows at least some signs of life.

The danger is that the leaf blades of the seedlings begin to wither, turn yellow and may fall off. New leaves can grow in place of fallen leaves, but they often grow wrinkled and underdeveloped.

White plaque greatly affects photosynthesis, slowing down this process. If you do not start fighting powdery mildew, the seedlings will die.

Traditional methods

Such methods are most suitable for treating the disease in the early stages of its development. The most effective means:

• A solution of soda and soap. Method of preparation: dilute 50 g of soda and the same amount of laundry soap in 10 liters of warm water. Spray the seedlings with the prepared solution 2 times a week until the disease completely disappears. Try to get on both sides of the leaves. The plaque formed on the leaves of tomatoes will prevent the fungus from developing further.
• Serum treatment. It is diluted with water (1 liter of whey per 10 liters of water). The product is sprayed on seedlings 3-4 times with a break of 2-3 days. After treatment, a film will appear on the leaves, which will not allow the fungus to breathe, thereby leading to its death.
• Infusion of wood ash. Add 1 kg of ash to 10 liters of hot water. Leave to infuse for 7 days. After this, pour the solution into another container so that the ash remains in the first. The resulting solution is sprayed on tomatoes every other day until the fungus disappears.

Chemicals

Powdery mildew is killed by fungicides. Products must be prepared according to instructions.

During processing, it is also important to observe safety measures: wear protective clothing and, if possible, ventilate the room.

It is recommended to wear safety glasses to protect your eyes.

Effective drugs:

1. "Topaz".
   Dilute 2 ml per 10 liters of water, stir thoroughly. Treat the plant every two days. The treatment is carried out until the fungus is completely destroyed. The cost of the product is 40-50 rubles.
2. "Tiovit Jet".
   For 10 liters of water you need to take 20-30 g of the drug. Seedlings are treated 5-6 times in 2 months. It is better to start spraying in advance, as this product is an excellent prevention of the development of powdery mildew. Price - 50-60 rubles.

Biological drugs

There are many different biological drugs available on the market. However, the most effective of them are:

• "Epin."
• "Immunocytophyte".
• "Fuzaksin".
• "Monofilin".
• "Baktofit".
• "Gumat".

These products help fight fungus not only in tomatoes, but also in other crops. The drugs are suitable for both the prevention of the disease and its treatment.

Other control methods

If you notice white spots on the leaf blades, you must definitely change the soil. This is explained by the fact that fungal diseases can live in the soil for a long time.

Infected plants must be disposed of immediately to prevent the spread of the fungus.

Sunburn on young seedlings

Considering the question of why the tomato leaves turned white and what to do to save the plants, I would like to immediately draw your attention to the fact that there are many reasons for this phenomenon. Of course, most often the leaves on tomato bushes begin to turn white as a result of some kind of infection or in case of improper care of the crops grown

If you do not want to lose your tomato harvest, carefully study the features and rules of planting and cultivating tomatoes.

So, why do the leaves of tomatoes in a greenhouse turn white, you ask? One of the most common reasons is exposure of young seedlings to ultraviolet rays. Simply put, if the leaves of the tomatoes have turned light green, then we can confidently say that the plants have received sunburn. Most often, a similar phenomenon can be observed during the period of transplanting seedlings from containers or greenhouses into open ground.

Young tomato bushes, which were accustomed to dark areas, were not ready for such drastic changes and became stressed. To prevent this situation from occurring, try to gradually accustom your plants to sunlight. For example, it is recommended to expose seedlings in containers to the street every day. Greenhouse crops need to be opened and ventilated more often.

Main reasons

If the leaves of tomato seedlings turn white, then experienced gardeners, analyzing additional symptoms, can assume:

• sunburn;
• eating disorders;
• soil salinization as a violation of agricultural technology;
• bacterial and fungal diseases, including cladosporiosis, powdery mildew, mosaic, septoria.

See also: White spots on tomato seedlings