Recently, many gardeners have been trying to use greenhouses to grow tomatoes. Lush green tomato bushes protected by polycarbonate attract with bright, fleshy and juicy fruits that ripen several weeks faster than ground ones. And although plants are protected from weather surprises, numerous diseases tomatoes in a greenhouse made of polycarbonate become a real scourge of vegetable growers.
Over the years, diseases in tomatoes become more and more common, and in a greenhouse, the infection quickly spreads among the seedlings. Among the causes of diseases, several can be identified:
- violation of agrotechnical growing conditions;
- significant susceptibility of selected tomato varieties to pathogens;
- increased humidity inside the greenhouse;
- contamination of greenhouse soil with pathogens;
- choosing unhealthy seeds.
Before growing tomato seedlings, the greenhouse must be disinfected and the seeds must be treated. It is necessary to periodically ventilate the room and inspect the bushes.If at least one diseased plant appears, it should be removed immediately and the causes and type of disease should be found out. Diseases of tomatoes in a greenhouse can be divided into three large groups.
Fungal diseases
If a fungus appears in a greenhouse, it can spread very quickly and destroy the crop. Its appearance is usually promoted by high humidity. A significant number of tomato diseases in the greenhouse that require urgent treatment are caused by the fungus.
Anthracnose
Its pathogen is often transmitted from weeds. The fungus is considered a weak pathogen and can exist for a long time in a dormant state in the soil, but with a sharp increase in humidity and temperature, it wakes up. The first signs of tomato disease appear on ripe fruits in the form of small depressed spots, then turning into dark rings. The tomatoes begin to rot inside. Green fruits, stems, leaves, as well as the soil around the bushes are also affected. To prevent fungal disease of tomatoes, the following measures should be taken:
- when purchasing seeds, choose a certified product;
- control the level of humidity and temperature in the greenhouse;
- remove growing weeds in a timely manner;
- tie the bushes to pegs, preventing the fruits from coming into contact with the ground;
- periodically alternate sowing tomatoes in a greenhouse with other crops;
- spray the seedlings with fungicidal solutions.
Late blight
This is the most dangerous of the fungal diseases of tomatoes in a greenhouse; its signs are clearly visible in the picture:
- brown foliage;
- the appearance of powdery plaque on the lower leaf blade of seedlings;
- dark spots on the fruit.
Gradually, the tomatoes begin to rot, and the entire crop is lost.
Many home methods are effective for preventing and treating tomato diseases. The fungus is afraid of garlic. Garlic spraying in the greenhouse should begin from the moment of formation. ovaries on tomato bushes and carried out every two weeks. You can also add a little potassium permanganate to the garlic infusion. A good preventive measure against tomato diseases in a greenhouse is spraying with a solution of table salt. Before the procedure, you need to inspect the bushes and remove already damaged leaves. A 2-3 percent saline solution forms a thin film on the foliage, which protects it from the penetration of fungi.
Having planted tomato seedlings in the ground, after about ten days you can begin weekly kefir spraying. They will be a good prevention against diseases. Iodine added to water with milk will protect plants from fungi and speed up the ripening of tomatoes.
Ash ones have proven themselves well processingwhich are carried out after planting tomato seedlings, during budding and when the ovaries appear. Seedlings are effectively protected from tomato disease by spraying with an infusion of dried and crushed tinder fungus. They should be started during the formation of the ovaries and carried out with a frequency of once every 10 days. If signs of late blight appear, you need to treat the tomato bushes additionally.
An original method for increasing disease resistance of tomatoes in a greenhouse was proposed by scientists from Germany. In a simpler version, the method consists of piercing the hardened stems of tomatoes with pieces of copper wire up to 4 cm long. The puncture is made about 10 cm above the ground, the ends of the wire are bent down.Copper in microdoses enhances respiratory and oxidative processes in plants, improving the production of chlorophyll in tomato seedlings.
Fusarium
The fungus that causes tomato disease, is activated at high humidity and temperature. Symptoms appear as:
- yellowed and falling lower leaves;
- deformed petioles;
- pinkish-yellow coating on the root collar of plants.
Gradually, the fungus grows inside the stem, the plant weakens and dies.
Prevention of this tomato disease includes the following:
- the fungus accumulates in the soil, so you need to change the soil in the greenhouse or disinfect it;
- after harvesting, all tomato tops should be destroyed;
- Tomato disease can be caused by excess nitrogen - you should not get carried away with manure feeding of plants;
- you need to make sure that there is a layer of earth 10-15 cm thick above the root collar, so the tomatoes need to be hilled;
Root rot
This dangerous tomato disease often appears when the soil moisture in the greenhouse is high. Although it mainly affects the roots of tomatoes, its signs are also visible on the above-ground parts of the plants:
- the stem in the lower part becomes thinner, withers and dies;
- the leaves first wither during the day and are restored at night; as the disease develops, they already dry out;
- the stem seems to be torn apart, and the root neck of the tomatoes turns black.
To treat tomato disease, the following measures are necessary:
- damaged tomato bushes must be destroyed immediately;
- dry the soil with sand and provide ventilation in the greenhouse;
- sprinkle the root part of the plants with calcined sand or ash;
- to stimulate the growth of additional roots, add a layer of steamed peat on top;
- treat with a fungicide and water the tomato roots with a growth stimulator.
If a tomato disease has affected too many plants, it is better to completely change the soil in the greenhouse and replant tomato seedlings.
Alternaria blight
When this occurs tomato diseases in the greenhouse, dry brown spots appear on all parts of the plant, including fruits. As they grow, they lead to wilting and death of tomatoes.
Signs of Alternaria blight can be distinguished from late blight:
- with the first disease, the spots remain dry at any time, and their outlines are rounded, with clear boundaries;
- As the disease progresses, the leaves turn yellow, which does not happen with late blight - it produces large, blurry spots.
When signs of disease appear on plants, fungicide treatment should begin.
Cladosporiosis
This fungal disease of tomatoes has another name - brown spot. It is especially common in greenhouses and affects tomatoes during the flowering period. Brown spots appear first on the lower leaves of tomatoes, and then spread to the fruits. If there are already lesions, you need to treat with fungicides, and after harvesting the tomatoes, treat the greenhouse with a solution of copper sulfate.
Gradual withering of seedlings
In greenhouses, the phenomenon of slow wilting of tomatoes is often observed. It can be caused by several reasons.
- Sclerotinia appears first as whitish spots on the leaves. Then the entire plant becomes discolored and dies. When the first signs of tomato disease appear, you need to replace the soil in the greenhouse or disinfect it.
- Didimella fungus causes symptoms such as black spots on the stalks of tomatoes. Bordeaux mixture will help cope with it.
- One of the most dangerous and common tomato diseases in greenhouses is gray rot.. It very quickly takes over the greenhouse space and destroys all tomato seedlings. Gray rot is carried with the soil, so it is necessary to disinfect it and normalize the temperature and humidity in the greenhouse.
Powdery mildew
This is a common tomato disease in greenhouses; the photo shows the affected plants.
It occurs when drip moisture forms in the greenhouse. Its first signs appear in the form of a white coating on the leaves, reminiscent of spilled flour. With development tomato diseases leaves curl and fall off, the plant dies. Powdery mildew is difficult to control. As means of control, you can use spraying solutions:
- colloidal sulfur;
- copper sulfate;
- mullein with added urea;
- soda ash with urea;
- whey;
- dry mustard;
- garlic infusion.
Viral diseases
This type of tomato disease is dangerous because no effective control methods have yet been found against it. Therefore, it is easier to prevent them by treating the seeds and soil with a solution of potassium permanganate before planting.
Aspermia
The tomato disease was first discovered in the 40s of the last century. Its main features:
- excessive bushiness of the tops of plants;
- inhibition of growth of the main and side shoots;
- wrinkled, curled leaves;
- deformation of fruits.
Tomato necrosis
The causes of this tomato disease are associated with factors such as:
- insufficient illumination of plants;
- poor ventilation in the greenhouse;
- excessive watering;
- saturation of the soil with nitrogen fertilizer.
Mosaic
Tomato disease appears as light green spots on leaves. The speed of plant development decreases, and the virus persists on the seeds.
Bacterial
The most dangerous bacterial diseases of tomatoes in a greenhouse - photo. Treating them is very difficult - it is almost impossible to save the crop, so it is better to carry out preventive work before planting tomatoes:
- disinfect seeds;
- annually change the top layer of soil and disinfect the soil in the greenhouse;
- diseased plants should be removed and burned as quickly as possible;
- disinfect used tools.
Black spot
Symptoms of tomato disease first appear on the leaves in the form of small brown spots, which gradually increase in size and cover all parts of the plant, including the fruits. Gradually it dies. To combat the disease, it is necessary to thoroughly spray tomato seedlings with bactericidal solutions and Bordeaux mixture. But the most important thing:
- detect and remove affected parts of plants in a timely manner;
- make sure that the tomato seedlings are not too thick;
- annually change or disinfect the soil in the greenhouse;
- After setting the fruit, you can remove the lower leaves on the tomato bushes.
Tomato cancer
This dangerous tomato disease begins with wilting and curling of the lower leaves of the seedlings. On sections of the stems you can see darkening and a yellow empty core. Spots also appear on the fruits, due to which the tomatoes lose their presentation. High humidity in the greenhouse and temperature contribute to the development of cancer. In the fight against tomato disease, copper-containing fungicides provide effective assistance, but timely prevention is better.
Pests
Tomatoes in greenhouses have a variety of pests that can cause disease symptoms. Therefore, you should regularly carefully inspect the bushes in the greenhouse and the soil around them.
Spider mite
The pest is very small in size; it entwines tomato bushes with a thin web and sucks out the plant juice. As a result, tomato leaves dry out and fall off. Ticks usually exist in colonies and hide on the undersides of foliage, under clumps of soil and fallen leaves.
To combat the tomato pest, the following measures will help:
- since they die in high humidity, you can water the plant abundantly and cover it with a plastic bag;
- up to half of the insects are destroyed by wiping the leaves with soap and water;
- It is good to spray tomato seedlings with garlic or onion infusions, and you must also wet the underside of the leaves;
- Dandelion infusion is also effective;
- thoroughly spraying tomatoes with phosphorus and sulfur preparations will also be beneficial;
- Ticks are afraid of ultraviolet radiation, which can be used in the fight against them - you need to irradiate all the nooks and crannies where they hide.
Whitefly
These pests of tomatoes in the greenhouse are small insects, the larvae of which stick to the leaves and feed on the juice. They can be detected by some signs:
- the appearance of flying midges resembling a moth above the seedlings;
- the appearance of a white cloud if you shake a tomato bush;
- the presence of a black coating, which is caused by an accompanying fungus;
- shiny sticky coating on tomato leaves.
Means to combat whitefly:
- glue traps - their disadvantage is that beneficial insects are also destroyed;
- Wipe the underside of the tomato leaves with cold water and soap;
- significantly reduce the temperature in the greenhouse - to about 10 degrees;
- Spray tomato seedlings with infusions of garlic or yarrow.
Gnawing owl
This tomato pest, which are caterpillars up to four centimeters in size, are invisible, as they hide in the soil during the day and feed on the plant at night. After wintering, adult caterpillars gnaw tomato stems, and the larvae feed on the pulp of the fruit, penetrating inside. At night, the caterpillars reach the fruits and leaves of tomatoes, gnawing them. One individual can spoil 10 bushes during the night.
To fight, you can use various folk remedies:
- butterflies will be repelled by spraying seedlings with a decoction of tomato tops or an infusion of wormwood or tobacco;
- you can catch them using sweet bait in the form of fermented juices and jam;
- It is necessary to periodically loosen the soil in the rows in the greenhouse;
- remove weeds from the beds more often, especially in August, during egg laying.
Wireworm
Damage to the roots and stems of tomatoes is caused by the larvae of click beetles - yellow caterpillars. The fight against wireworms must be carried out comprehensively:
- when planting tomato seedlings, you need to put a handful of onion peels in each hole - this measure will repel the pest;
- dry mustard can successfully replace onion peel;
- Green manure will also help, the wireworm is especially afraid of peas and beans;
- using crushed eggshells or ash, you can reduce the acidity of the soil in the greenhouse - this is an effective measure against any pests of tomatoes;
- You can use traps in the form of a fishing line with pieces of potato strung on it - it is placed in the ground at a depth of 10 centimeters, and after a while it is destroyed along with the caterpillars.
Root nematode
Pests of tomatoes in a greenhouse are small worms that feed on the roots of tomatoes, weakening them. They also produce toxins that form growths on the roots of tomatoes. The plant loses the ability to fully receive nutrients and dies. An excellent preventive measure against tomato pests is the use of trap plants. The soil is sown with green manure plants - peas, soybeans, vetch or other crops. Their roots secrete substances that attract larvae. The pest invades the root system of green manure, after which the plants are mowed down and embedded in the soil. The pest dies before completing its development cycle.
Medvedka
This dangerous pest even reaches greenhouse tomatoes. It lays eggs in the soil, from which larvae emerge after three weeks. They gnaw the roots of plants. You can fight mole crickets with folk remedies:
- sow the rows of tomatoes with marigolds or calendula;
- water the soil around the tomatoes with solutions of onion peels or chicken droppings;
- fill the rows with sand soaked in kerosene;
- traps placed in the ground are effective;
- Crushed eggshells mixed with unrefined vegetable oil will be a destructive bait for the pest and at the same time an excellent fertilizer for tomatoes.
Conclusion
In order not to lose the harvest of delicious tomatoes grown with such labor and love, you need to choose healthy seeds, strictly adhere to the rules of agricultural technology and carry out preventive treatments in the greenhouse in a timely manner.
