Diseases of tomatoes can manifest themselves both in the greenhouse and in the open field. Viral diseases are quite common, and every gardener has encountered some types of tomato diseases. Diseases can harm plants, make fruits unfit for consumption, reduce yields, and the early stages of diseases can be easily overlooked. Viruses and fungi appear closer to autumn. The occurrence of diseases is directly related to environmental conditions. Timely treatment and disease prevention can save your crop. For planting in open ground or a greenhouse, you need to select varieties that are resistant to major diseases.
Fungal diseases
Fungal infections appear on fruits, stems and leaves. The leaves are ill in such a way that brown spots form on them, and a pale yellow zone appears around them. If the weather is humid and warm, such spots grow rapidly. A plaque appears from the bottom of the leaves. It is located over the entire surface of the infected area, or along the contour. Fruits can hurt at different stages of development. Green fruits, after they are sick, are covered with hard spots. The inner tissue of the fetus becomes light brown. The size and shape of the spots can be different – from concentric to ring-shaped. If the tomato disease develops successfully, the fruit turns brown completely.
Fitoftoroz
Late blight refers to fungal diseases. In addition to the usual manifestations, this tomato disease is characterized by the formation of spore-bearing signs, which are the result of repeated or secondary infection. On diseased stems, negative factors such as irregularly shaped spots appear.
The color of these spots is dark brown. They are often interconnected and form necrotic intercepts. Mushroom plaque does not appear on the surface of the plant. Prevention – soil sterilization, removal of diseased tomatoes. For chemical influence, sodium humate and Pseudobacterin are suitable.
Alternaria
Dry spotting, which is also called Alternariosis, entails the appearance of concentric brown spots of a rounded shape. The first manifestations of tomato disease can be seen on the lower leaves. Further, the disease spreads up the plant, and the manifestations become noticeable on the upper tiers. The affected areas are covered with spots with a diameter of 4-7 millimeters. After some time, their size increases, they become larger and can reach 10-15 millimeters in diameter. In protected ground, early manifestations are removed by Quadris, and for open ground, other substances are used – Ridomil and Metaxil.
Antraknoz
Roots of adult plants are exposed to anthracnose. They are covered with brown spots, the bark is flaky, microsclerotia are collected under it. Mature fruits are affected after ripening and can become infected during full ripening or transportation. The causative agent is a fungus that can spread at high humidity, which can be in protected ground. If the leaves and stems of the plant are covered with drops, they can cause the spread of the disease. Treatment can be carried out with chemistry, Agat-25, spraying. Breeders have bred varieties and hybrids of tomatoes that are not susceptible to diseases, and are called F1 Life, Longf, Shelf. 
White spot
White spotting (septoria) is very dangerous, as it can lead to the loss of half of the entire crop. Old leaves, those closer to the ground, are affected. After being coated with stable spots, they turn brown and dry out. The best temperature for the development of spotting can be from 15 to 27 degrees with a humidity of 77%. Even in the remains of the plant, spores of the fungus remain. It is impossible to protect the plant from infection even with the help of chemicals. Some hybrid tomato varieties may be immune to spotting.
Gray mold
Gray rot is very dangerous. Infections spread to the entire stem, and tissues die as a result of necrosis. Visually, the rot resembles a grayish-white coating, its appearance destroys the fruits, and the whole plant simply fades after infection. Generative organs are affected by high humidity. Also, the infection can be transmitted to other crops (which can be very likely in protected ground) that can grow with or near tomatoes. For treatment, experts advise using timely agrotechnical measures, chemical preparations, such as growth regulators and chemical protection. The names of the drugs are Bayleton and Euparen.
White rot
White rot is also called sclerotinosis. A plant can become infected with a disease as a result of mechanical damage. The effect of the disease may increase as a result of a decrease in temperature and an increase in humidity – after cold rains. Poor ventilation in the greenhouse and planting density can also cause the development of the disease. Signs – wilting, rot of the stem, the formation of cavities, the appearance of black sclerotia, white fluffy plaque, the death of the plant. The causative agent of the disease can remain on the remains of the plant and in the soil. Disinfection of the soil, which must be done after the previous planting, will help get rid of the pathogen.
Mučnistaâ rosa
Powdery mildew infects tomatoes through the air, infection is carried out by the spread of conidia. The result of infection is a white coating that appears on the upper or lower side of the leaf. Sometimes appears on petioles and stem. The tissues then die off, and the leaves may fall off. 
Low air humidity is quite sufficient for infection, however, the first signs appear at a humidity of 80-90% and a temperature of 16-20 degrees. Diseased plants grow poorly, the number of fruits and their size decrease. The causative agent is a fungal infection. It is treated by spraying, sodium humate completely destroys the fungal infection. There is one stable hybrid variety – Milano F1.
Verticillosis
The symptoms are most severe during the growing season and during the flowering period. First, the lower leaves wither, spots form on them, which lead to twisting and drying. Further, the symptoms pass to the whole plant. The fungus passes through the vessels and clogs them. Under a microscope, you can see the mycelium, it is not pigmented, that is, colorless. The main thing for the fight is the cultivation of disease-resistant tomatoes, since there is no chemistry for treatment and prevention. Breeders have created a variety of Salting, resistant to verticillium.
Root rot
Root rot is very harmful and it appears on those areas of the earth that are watered too much.
It can occur on the plant immediately after planting, if the soil is already infected with it. On the substrate and open ground, it occurs in areas with excess moisture. The development of the disease occurs throughout the life of the plant. Symptoms – blackening in the root and neck, black leg. As a result, wilting of the sprout can be observed. Sometimes rot can provoke the appearance of other diseases. Unsterile soil and excessive watering can encourage the development of this defect. Treatment and prevention – soil disinfection, dressing of seeds and seedlings, treatment with Rodomil Gold as a preventive measure, treatment of the substrate.
stem cancer
Stem cancer does not manifest itself everywhere, and its appearance depends on the place where the tomato grows. In the open field, stem cancer is rare, but in greenhouses it can destroy the entire crop. 
When stem cancer affects the stems most often, and sometimes the leaves. Gum begins to ooze from the stems, and the flowers become underdeveloped. The development of the didimella virus occurs in wet weather and low temperatures. Treatment – disinfection of the soil, the use of the drug Trichodermin. Sprouts and stems are sprayed with preparations to stimulate growth, Agat-25 or Immunocytophyte. Pathogenic spots are treated with Rovral and chalk paste.
Fusarium wilt
Fusarium affects adult tomatoes and seedlings. Plants wither and die, may be underdeveloped. The first sign is wilting of the top. Tissues become sluggish, and individual leaves wither and curl. The process starts at the top of the sheet. If the stem is cut and examined, browning in the vessels can be seen. Sometimes healthy plants can die in one day, namely at night. The infection spreads through the soil, which should be light and structureless. Fluctuations in temperature and humidity contribute to the development of fusarium. Watering before planting pseudobacterin, growing resistant varieties – these are the methods of struggle.
Bacterial
Such diseases can pose a great threat to the crop. The vascular system is affected and the tomato wilts. Spots appear on fruits and sprouts. Problems begin on the sheeting located below. Humidity and temperature contribute to the development of the disease. Sometimes even spraying and sprinkling does not bring the desired results.
Bacterial mottle
This type of growth disorder is difficult to develop in a greenhouse. Visually determined very easily. The first spots appear on the leaves, later they turn brown. The result of the disease is death.
Mottling develops at high humidity and low air temperature. Mushroom carriers of the disease persist in the seeds. The problem does not appear often; for its treatment, chemical fungicides rich in copper are used.
Bacterial cancer
Bacterial cancer can be very harmful – damage can reach thirty percent of the entire crop. Everything is distinguished by a whole lesion of plants, at the beginning of the infection, the leaves wither. Hotbeds of bacteria become visible on the petioles in the form of brown growths. Wilting starts from the bottom of the plant. The stem also has a yellow pith. The fruits spoil outside, but also inside, covered with white spots.
Internal infection is much more severe than external infection, although the fruits are unsuitable in both cases. For prevention, the seeds are urinated in a solution of TMTD. Copper-containing fungicides are needed for spraying plants during the growing season.
bacterial wilt
Tomato bacterial wilt can be called a quarantine problem. This disease is considered the most dangerous. It is found throughout the territory of the CIS countries. Symptoms of tomato disease are very difficult to see with the naked eye. Tomatoes wither very quickly, after which they die, the infection can go into a chronic stage. Only surviving plants can be treated, others are destroyed. You can fight it by spraying Fitolavin with the addition of liquid glass.
Root cancer
Root cancer is rare, manifested by growths on the roots. They are small, inside them there is a concentration of bacteria. Tomato disease is determined using indicator plants. The source of infection is considered contaminated soil, and in order to avoid the spread of the disease, the roots are injured. Also, the virus dies when the soil is steamed. Soaking seedlings, its roots in Fitosporin is also effective as a fight against cancer.
Wet fruit rot
Wet rot affects green and ripe fruits, this can happen during the growing season, during ripening and during transportation. First, spots appear, in appearance they are depressed and delimited from the healthy zone. For 2-3 days, the pulp rots, turns into a liquid and colorless mass with an unpleasant odor. After that, the skin of the tomato bursts and takes the form of a bag. 
Immature fruits are particularly susceptible to infection. If the storage temperature of the tomato is high, then 5-7 days are enough for it to rot. To prevent this from happening, it is necessary to eliminate pests and maintain the right temperature during storage and transportation.
Black spot
The infection can damage a large part of the crop. The remaining and surviving fruits lose their appearance and taste. Tomato disease proceeds in such a way that the plants become unstable and have an unhealthy appearance. Treatment with chemicals can help solve the problem, the frequency of treatment is 10-14 days.
Viral diseases
Virus diseases of tomatoes can be very harmful. Everything depends on the virus that affected the sprout, the place of growth and the tomato variety itself. The fight against them comes through the destruction of bacteria-carrying insects, the cultivation culture is maintained, agromechanical influences are carried out on plants and their growth process.
Seedlessness
The harmfulness of aspermia has been proven, and depends on the type of virus and the conditions in which the tomato grows. Underdevelopment of generative sprouts, strong tillering – these are the signs of this disease. Any varieties are exposed to it, and the spider mite is considered a peddler, which must also be fought for this reason. 
The leaves become small, change pigmentation, and the flowers get the ability to grow together. In order to prevent the development of the disease, it is necessary to destroy insects that carry the infection, do not use reservations.
Bronze
The wilting of the leaves and their twisting is called bronze. The virus is getting stronger every year. Plants grown in greenhouses are very susceptible to problematic wilting. In addition, a complete loss of the entire crop is possible. Drawings of brown color appear on the fruits, and later on the leaves, which leads to the death of the tops. The disease is not cured, however, at a temperature of 45 degrees, the activity of the virus is canceled.
yellow curl
A very unpleasant moment can be yellow curl. It affects the appearance of ripe tomatoes. Their presentation is lost, the plants are colored unevenly, and the leaves are twisted, become small and deformed as a result of twisting. The carrier of the virus is the whitefly, which must be fought, and treatments are carried out in any possible way. One of the hybrid varieties is resistant to the disease, and is called F1 Senzafin.
Top bushiness
It manifests itself in winter, dots appear on the leaves, which turn white. They darken and cause necrosis. The leaves are stretched and twisted. Infected plants grow poorly, deform, their leaves become coarse. The infection is transmitted by aphids, there is no protection against the disease, to get rid of the problem, processing is carried out by agromechanics. 
Mosaic
Mosaic can quickly damage many plants. It can also lead to a complete lack of harvest.
Leaves are the first to be infected. They become stained, their original shape and color are lost. Together with other viruses, a new tomato disease can form. The virus is resistant to changes in temperature and humidity and is carried by insect pests. For prevention, normal plant growth conditions are observed. Compliance with the rules of crop rotation will help to fight, or rather, prevent many diseases. It is necessary to monitor the place and order of planting, to find varieties that are resistant to common diseases.
Video “Diseases of tomatoes”
After watching the recording, you will learn what diseases of greenhouse tomatoes are and how to deal with them effectively.
