White spots on the leaves of tomato seedlings: causes and treatment
Perhaps there is not a single gardener who would not grow tomatoes. Although tomatoes can hardly be attributed to capricious crops, but without proper care, they can get sick. White spots may appear on the leaves, having different shades and sizes. The reasons for the appearance of white spots can be different, consider the most common of them.
Why did they appear?
Nightshade crops are considered the most popular plants among gardeners. When growing tomatoes, they need constant care: from sowing seeds to picking seedlings and planting bushes in the ground. It is necessary to maintain optimal temperature and humidity so that signs of tomato disease do not appear.
If white spots appear on the leaves, it is necessary to find out the causes of their occurrence. Let's consider the main ones.
- Fungal infections. They can be considered the main cause of planting material diseases. The appearance of light or brown spots on the leaves will indicate a fungal infection.
- Viral infections, which pose a serious problem for seedlings. One of the most insidious viral diseases is considered to be “mosaic”, at the first symptoms, the leaves begin to acquire a multi-colored color.
- Parasites. The whitefly can cause great harm to the plant, its larvae wrap the leaves in cobwebs, after which white spots appear on them and the plant dies.
- Burns. If the seedlings are not hardened, but planted immediately in a permanent place, unprepared sprouts will start to hurt.
Planting seedlings in a permanent place should be carried out only after the plants have been prepared for new conditions. To do this, the seedlings are taken out for some time from the room to the air and left for hardening. The time should increase every day. When the plants have adapted to the new weather conditions, they can be planted in the ground. In this case, damage to the leaves by sunburn will be reduced.
In the first days after planting the seedlings, it must be shaded and protected from the scorching sun on the bushes.
White spots on the lower leaves may appear due to a lack of essential trace elements in plants, such as phosphorus, nitrogen, potassium, calcium, molybdenum and magnesium. If spots appear on the upper leaves, this indicates that the plant does not have enough chlorine, iron, manganese, boron. To cope with this problem is not difficult, you just need to purchase a suitable fertilizer in a specialized store.
in the greenhouse
In order to put a plate with a fresh salad of tomatoes and herbs on the table in the summer, you need to take care of the seed material in the winter. Seeds before planting are recommended to be placed for some time in potassium permanganate. After such treatment, the risk of disease in tomato seedlings will be less.
Seeds are sown in specially prepared containers and provide them with the right conditions. It is necessary to ensure that the room has a comfortable temperature for their growth and the optimal amount of moisture.Seedlings are planted in the ground when the sprouts become strong and have a height of at least 20 cm. After planting in open ground, the plant is shaded to protect the leaves from burning, otherwise their tips will begin to dry and twist. Sunburn can affect both the upper and the inner part of the leaf, as a result, they begin to dry out and fall off.
If white spots appear on the seedlings, it is necessary to remove the infected plants. At the first signs of the disease, it is important to quickly get rid of the cause, otherwise all the bushes may die.
To protect plants, seedlings are treated with fungicidal preparations. Processing is carried out after 12-14 days. Many gardeners prefer to process seedlings with environmentally friendly biological products. One such remedy is iodine solution. To prepare it, you need to take:
- iodine - 15 drops;
- milk - 500 ml;
- warm water - 5 liters.
Tomato seedlings are sprayed with this composition after 2 days.
For processing, you can use another effective method. You need to take:
- laundry soap - 1 bar;
- bucket of warm water.
Often, gardeners use an infusion of wood ash and potassium permanganate.
Tomatoes in greenhouses can often be affected by cladosporiosis. Usually this pathology occurs in the middle of summer. Varieties with reduced disease resistance or hybrids begin to develop spots. When plants are infected with cladosporiosis, leaves begin to fall off en masse, which leads to a decrease in yield.
Symptoms of brown spot or cladosporiosis:
- the first spots appear on the lower part of the plants and then begin to move to other areas;
- the spots are gray in color, and then change color to a darker one;
- due to the development of the disease, dry leaves begin to curl and fall off.
Sometimes the disease can affect not only leaves, but also flowers and fruits. If the plant is not treated, the disease in greenhouse conditions can persist for a long time, up to ten years. The development of cladosporiosis can be activated if the room has high humidity (above 80%) with an air temperature of about 22-25 degrees.
When plants are infected, it is necessary to monitor the temperature and humidity in the greenhouse and process the inventory so that the disease does not spread to healthy bushes.
At the first appearance of the disease, it is necessary to remove the affected leaves. It is better to stop watering and try to ventilate the room more often. For greenhouse cultivation, it is worth choosing varieties with high disease resistance.
You can get rid of cladosporiosis by disinfecting and replacing the soil. Plants are treated with "Pseudobacterial" or use "Fitosporin". After 18-20 days, the bushes should be processed again.
A lot of trouble can be caused by a viral mosaic disease, which can affect plants both in the greenhouse and after planting in the ground. Seeds are most often infected, so the material should be purchased only from reliable manufacturers and processed before sowing. With a mosaic, the leaves begin to be affected by spots of different shades, they acquire a kind of mosaic pattern. It is difficult to fight this disease, therefore, at the first sign, diseased plants must be pulled out and disposed of. After that, the entire area should be treated with potassium permanganate.
In the open field
Before planting seedlings in the ground, plants are hardened for several days.Under the bright scorching rays of the sun, plants without prior training can get burned, and then transparent spots will appear on the upper leaves. To help the seedlings and heal them from burns, you can use the Espin tool, they are recommended to treat the bushes in the evening.
After getting burns, the color of the leaves can no longer be changed. But when using the drug, the bushes will be able to recover, and new green leaves will appear. Bushes are treated with Espin once a week. 3-4 treatments should be carried out. Plants that get sunburned will be weaker and will start fruiting a week or two later.
Kinds
When white spots appear on the leaves of seedlings, it is necessary to find out what disease the plant has undergone. It could be:
- powdery mildew;
- white rot and brown spot;
- septoria;
- late blight.
powdery mildew
Often, gardeners notice that a white-gray coating has formed on the lower part of the leaves, then the spots turn yellow on the upper part. Soon the green leaves begin to dry out and die. The cause of the disease may be high humidity. In rainy and foggy weather, the fungus begins to become more active.
At first, the infection affects the lower leaves, gradually spreading to the entire plant. If tomatoes are affected by powdery mildew after flowering, they will begin to crack and rot.
Septoria or white spot
Usually, the disease can affect plants that are planted in the ground. If small bright dots and spots with a dark gray border appear on the leaves, one can judge the development of the disease. After the appearance of the disease, the plant stops growing, and dry leaves remain on the bush, which have twisted.Due to septoria, you can lose the entire crop of tomatoes.
What to do?
To get a good crop of tomatoes, plants need constant care. In the event of the development of the disease, it is urgent to take measures and treat the seedlings with special preparations.
To get rid of powdery mildew, plants should be fed with potassium and phosphorus, while nitrogenous fertilizers should not be applied, since their excess reduces the plant's immunity. Against powdery mildew, fungicides "Fundazol" or "Fundazim" can be used. During the period when flowering takes place, the plant is treated with "Pseudobacterin".
In addition to these drugs, you can use folk remedies. To do this, take whey, aged for 2 days, dilute it with water in a ratio of 1 to 9 and treat diseased plants.
Many gardeners often encounter late blight, not only tomatoes, but also potatoes are susceptible to this disease.
Signs of late blight:
- brown-brown spots with a whitish edging appear on the leaves, which increase very quickly;
- on the lower part of the leaf, a light coating appears, resembling a cobweb;
- leaves turn yellow, curl and dry;
- stems become dry and brittle.
The disease can spread very quickly, as it is transmitted from one bush to another in a short time. It is necessary to tear out the affected bushes so that the disease does not pass to healthy plants. If large areas are affected by late blight, it is worth spraying the plants with special preparations diluted with water. To combat late blight, boric acid, "Fitosporin", "Gamair" are used.
Prevention
At the first signs of tomato diseases and the appearance of white spots on the leaves, urgent measures should be taken and treatment begun, otherwise the crop may die.
In order to prevent the emergence and spread of diseases in the greenhouse and on the site, it is necessary:
- observe comfortable conditions in the greenhouse;
- before placing the seeds in the soil and before planting seedlings, treat them with disinfectant solutions;
- in case of severe damage to plants, they must be immediately pulled out;
- add the necessary trace elements to the soil;
- when planting plants in sunny areas, make sure that they are shaded at first.
For growing tomatoes, you should choose a place well lit by sunlight. When planting bushes, it is necessary that the distance between them is at least 60 cm, this will ensure proper ventilation, and they will be less susceptible to viral and bacterial diseases. If you plant bushes close to each other, with abundant watering or in the rainy season, late blight may develop.
During watering, you should try to pour water under the root and avoid getting drops on the leaves so as not to cause a burn to the plants. When applying fertilizer, it is important not to overdo it with their amount. This is especially true for nitrogen preparations.
When planting tomatoes, you need to prepare the bed in advance. To do this, it needs to be dug up and weeds removed. The plant is often affected by late blight, so you should not plant tomatoes in the place where the potato used to be, which is also susceptible to this disease.
To prevent plants from getting sunburn, you need to plant seedlings in places that will be more shaded. In this case, the seedlings quickly adapt to new conditions, the bushes will develop strong and healthy.
How to save whitened seedlings, see the next video.