In the article we will talk about the diseases of tomatoes, descriptions of the most common are given. From the material, you will learn how to prevent them and treat affected plants. Gardeners want to get big harvests, the more offensive it is to see when the fruits of their own labors literally disappear before our eyes. After all, plants, like all living things, can be subject to various diseases.
What can tomatoes hurt?
If you want to know what diseases of tomatoes threaten the tomato crop, there are 4 main groups. These are diseases:
- bacterial;
- mushroom;
- viral;
- non-infectious diseases of tomatoes.
The first group includes:
- stem pith necrosis;
- root cancer;
- black bacterial spot;
- wet fruit rot;
- bacterial wilting;
- bacterial cancer;
- southern late blight;
- fusarium wilting;
- bacterial mottling.
To the second:
- fusarium wilting;
- cladosporiosis;
- stem cancer;
- root rot;
- verticilliasis;
- white rot;
- gray rot;
- powdery mildew;
- anthracnose;
- alternaria;
- late blight;
- septoria.
The third group includes the following diseases:
- bronze;
- aspermia;
- yellow curl;
- bushiness of the top;
- the threadiness of the leaves;
- mosaic.
The fourth group of tomato diseases includes:
- hollow fruit;
- apical rot of fruits;
- stolbur.
Tomato bacterial diseases
With necrosis of the core of the stem, the disease begins to affect first well-developed bushes. In this case, brown spots form on the stems, which crack over time. Parts of the sheet are curled up. The damaged plant withers soon.
This disease also affects the fruits. On immature, a light mesh is formed, which does not disappear until maturation.
The most favorable temperature at which bacteria develop is + 26– + 28 ° С. At + 41 ° C, they die. The main source of infection is seed. To prevent the appearance of the disease, pickle the seeds with a solution of potassium permanganate before planting. If you do not grow seedlings yourself, purchase them only in reliable, trusted places. It helps to prevent the onset of the disease by growing resistant tomato hybrids, varieties such as, for example, "Red Arrow", F1 "Maeva" and F1 "Resento".
Since necrosis of the pith of the stem occurs in greenhouses where the humidity is high, ventilation is necessary after watering. You can water the tomatoes early in the morning and then keep the greenhouse doors open until evening. Necrosis can also occur due to the use of a large amount of nitrogen fertilizers with a lack of potassium and phosphorus.
Root cancer
When it occurs, growths appear on the lower part of the stem. To prevent this, it is necessary to injure the roots of the tomato as little as possible. After all, pathogenic bacteria enter this part of the plant only if it is damaged.
It will help to prevent such steaming of the soil before planting seeds, picking, soaking the roots of seedlings before planting in the preparation "Fitosporin M", removing plant residues after the growing season, digging the site.
General recommendations for combating bacterial diseases of tomatoes
Necessary:
- Use only healthy seeds. For prophylaxis, before sowing, you need to lower them for 15–20 minutes in hot water, the temperature of which is + 45– + 50 ° С, then cool for 3 minutes in cool water. After that, you can sterilize the seeds in aloe juice, at the same time giving them additional nutrition. For this, tomato seeds are soaked in aloe juice for 6-8 hours.
- Observe the crop rotation, growing tomatoes in one place for no more than two years, but it is better for 1 year and planting the nightshade there again no earlier than 3-4 years later.
- After the end of the season, it is necessary to remove a layer of soil 5–7 cm high in the greenhouse, carefully destroy plant residues.
- Plant disease resistant tomato hybrids and varieties. So, relatively immune to bacterial cancer "Siberian early ripening", to black bacterial spot: "Lightning", "Crown", "Juliana", "Potok" and F1 hybrids "Kronos", "Excellent", "Volzhsky". Variety "Ballada" is well resistant to black bacterial spot and Alternaria.
To prevent bacterial cancer, it is necessary to shed the soil with the Gamair suspension 1-3 days before planting seedlings or seeds, dissolving 2 tablets of this drug in 10 liters of water.
If you notice that one or more fruits are affected by rot or other diseases, pluck them, burn them or dispose of in another way, but do not put them in compost or leave them on the site.
Such diseases are often spread due to high humidity. Therefore, to prevent them, stop watering for a while and carry out daytime airing. If the leaves are affected, prune them, if the tomato disease is very widespread, remove parts of the plants or the bushes themselves completely. Collect healthy fruit that has a light green and always shiny surface. In boxes in a sunny or warm shady place of the room, they ripen. Spray the plantings with Fitosporin M. This remedy also helps well for the prevention of various diseases of tomatoes. It is enough to dilute 1 tbsp in 10 liters of water. l. of this drug and spray plants that are 100 sq. m. area or water 3-4 square meters. m. soil.
Against black bacterial spot, as well as late blight, spraying tomatoes with a solution of "Fitosporin M" with a concentration of 0.1% will help the first time a week after planting seedlings in the ground, then after 2-3 weeks.
Fungal diseases
This kind of infection is caused by various fungi. Late blight is the most common disease of nightshades, including tomatoes. Most often it appears on cloudy cold nights. Therefore, from the second half of July, it is recommended to tightly close greenhouses and greenhouses in the evening, and put a film on open ground tomatoes overnight.
If you have well-calcified soils, then such a soil is most attractive for phytophthora and other fungal diseases. Thickened plantings can be another reason. In such places, ventilation is worse, the humidity is higher, which is what phytophthora spores love. If brown spots appear on the leaves, stems, and then on the fruits, which grow quickly, this is late blight. To defeat a dangerous tomato disease, at the first sign of its occurrence, it is necessary to stop watering, cut off the affected tomato leaves with scissors, periodically rinsing the instrument in a solution of potassium permanganate.
Affected tomato fruits must be removed and disposed of, the rest must be put in a box and put to ripen. If the disease has not yet entered into full force, then the following measure will help to avoid damage to healthy fetuses: pour water into a basin or bucket, the temperature of which is + 45 ° C. Dip the tomatoes in it for one minute, then dry them.
Tomatoes left on the bushes can also be saved. For this, the plants need to be watered very rarely, only in the morning, so that during the day most of the moisture is absorbed into the soil, and its excess evaporates. If the weather is damp and humid, do not water at all, just loosen the soil around the bushes. If the soil is wet, you need to feed the tomatoes with potassium and phosphorus fertilizers, spray them with solutions of trace elements and "Fitosporin M".
Disease of tomatoes verticilliasis most often occurs in greenhouses, when tomatoes begin to bloom. First, the lower leaves acquire a light yellow spot, then the disease spreads higher, the foliage of the whole plant dries up, and it dies.
The parasitic fungus is found in soil with a low organic content and is activated at temperatures below + 20 ° C. Increasing this indicator to + 25 ° C avoids new infections.
Fusarium wilting outwardly resembles verticillosis, but at the first - a stronger chlorosis of the leaves. When this fungal disease appears, the cotyledons turn yellow on young plants and the seedlings wither. On older ones, the lower leaves turn yellow and wither, and the tops are attached. When symptoms of this disease appear, it is necessary to spray the plants and shed the soil with drugs of the benzimidazole group ("Benazol", "Fundazol"), they are able to restrain the development of the disease.
To prevent fusarium wilting, plants are watered with a solution of "Pseudobacterin-2" or "Planriz". It is possible, when growing seedlings, to water the soil around it with a suspension of "Glyokladin" or "Trichodermina" and add it when transplanting plants to a permanent place.
Powdery mildew
Several drugs will help to defeat this tomato disease. It:
- "Quadris";
- "Strobe";
- "Tiovit Jet";
- Bayleton.
They are used to process tomatoes of open ground and protected. "Quadris" will also help with late blight disease, Alternaria, and "Strobi" - with late blight.
Mosaic viral disease
It is most often found in this group of viral infections. When it occurs, the leaves curl, turn yellow and dry out.
Control measures: cultivation of varieties resistant to this virus, sterilization of soil, pots, washing garden tools. The spread of the disease can be reduced by sterilizing the pinching tools or by pulling off the stepsons by hand without touching other parts of the plant.
In the prevention of most diseases of tomatoes, compliance with crop rotation, cleanliness in the greenhouse, destruction of plant residues, non-thickening of crops, treatment with biological preparations will help. If the scale of the disease is large, it is necessary to remove the heavily affected plants and treat the rest with biological or chemical preparations.
For ways to protect tomatoes from late blight, see this video:
