How and how to treat gray rot on tomatoes?
Tomatoes are successfully grown in various regions of our country. A variety of varieties and hybrids helps to choose the most suitable species for the conditions. Nevertheless, there are situations when plants become infected, get sick... Therefore, you need to be prepared for such a situation, to know how you can cope with the problem. In our article, we will consider in detail one of the diseases of tomatoes - gray rot, as well as how to treat it.
Rot is a dangerous fungal infection that affects various vegetable crops, including tomatoes. Getting rid of plants from it is a laborious, long process.... Its success is largely determined by the timeliness of the protective measures taken and the correct diagnosis of the disease.
How does the disease begin?
The disease begins with damage to the injured plant stem. On the affected areas, spots of a gray-brown hue are formed. Then they grow along the stem within 5 days, encircle it... Then the spot brightens, stripes appear in its place. In the first week, there is still no gray rot fungus on the spot. The disease develops in the stem. Part of the stem dies off, through it the nutrition of the plant stops, it withers. Leaves above the affected area turn yellow.
Signs of gray rot are similar to those of pith necrosis. But there is a significant difference. With necrosis, the entire plant will wither, and with gray rot, only the part of the plant that is above the affected area withers. Most importantly, after 7-10 days from the moment of injury, a characteristic ash-gray plaque appears on the spot., by which the disease can be unambiguously identified.
The optimal conditions for the development of the disease are high air humidity. It develops during the formation of fruits, affecting all aerial parts of the plant. At the beginning of infection (of individual plants), the infection spreads relatively slowly... But with the onset of favorable conditions, it quickly infects neighboring plants. If distributed massively, it can destroy most of the crop.
The method of transmission is airborne. Other vegetable crops can be sources of infection: cucumber, lettuce, etc.
Rot types
There are several diseases, united by one name - rot.
Gray rot
Gray mold is a rapidly growing fungus
Fungal disease... Its appearance provokes Botrytis cinerea Pers. The disease can affect fruits grown both in greenhouse conditions and in the open field. For its distribution, high humidity, unbalanced nutrition (excessively applied nitrogen fertilizers) are needed. External manifestations of the disease:
- decay of the fruit of a grayish hue;
- characteristic fluffy bloom;
- leaf spot;
- affected plant stem.
The disease is spread from plant to plant... Having become infected, they rapidly wither and die. If rotten fruits are found, they must be collected and destroyed (burned or buried), but in no case left in the compost heap.
Brown rot
Brown rot is also called phomosis. This disease is very common. The place of plant damage is located next to the stalk.... The fungus enters the fetus due to a violation of its integrity due to rain or wind. Outwardly, it is not always possible to reliably determine the disease, because fruits may have only small brown spots. However, the tomato fruit will be completely rotten. The disease can be provoked by feeding plants with fresh manure, which is extremely undesirable for them.
White rot
The disease is caused by a pathogen Sclerotinia sclerotiorum. The crop is damaged during storage. The primary sources of fungus are compost and soil.
Signs:
- wateriness and discoloration of plant leaves;
- fruits covered with white bloom.
Most often, white rot forms on damaged areas of the fruit.
Additional conditions for the onset of the disease are: soil that has not been disinfected, low temperature in the greenhouse (below 18 ° C) during planting, high humidity.
Top rot on tomatoes
Vertex rot affects tomatoes that are grown in greenhouses and greenhouses. The disease spreads very quickly and can cause great damage to the crop in a short time. The initial symptoms are noticeable even in immature fruits.: Watery spots are much darker than the fruit. Then the stain turns brown, the fruit shrivels and falls off. Fungi may develop at the site of the appearance of rot, but the disease does not have a fungal nature of origin. Main reasons:
- aridity;
- insufficient watering;
- salty soil;
- lack of calcium or its increased content in fertilizers.
Top rot affects a significant number of tomatoes that are grown in greenhouse conditions.
Rhizoctonia or root rot
Root rot of tomatoes, also called black leg, is common.... It is caused by a complex of pests: phytopathogenic fungi: Rhizoctonia, Fusarium, Pythium, Phytophthora, or the phytopathogenic bacterium Erwiniacarotovora. Tomatoes, which are grown in greenhouses using a substrate, are especially susceptible to disease. Up to 70% of young plants can die from this disease.
The main signs:
- softened root collar;
- its blackening;
- the appearance of a constriction.
After the appearance of these signs, the plant withers and dies. The conditions of tomato infection include: high level of air humidity, excessive watering of the substrate, imbalance in feeding with minerals.
Where does rot on tomatoes come from?
Rot is a fungal disease. In order to avoid its unpleasant consequences, you need to know why it appears. Experienced gardeners name a number of unfavorable conditions under which the appearance of different types of rot is possible.
The most common are:
- unsterilized soil or substrate, in which spores of pathogens of various pathologies have survived, will provoke a massive infection of plants in greenhouse structures;
- using untested seeds, especially often their own;
- non-observance of the air humidity in the greenhouse, excessive accumulating moisture when watering plants will lead to fungal infections of vegetable crops;
- no less dangerous and insufficient watering since in this case, the plant lacks nutrition, it weakens, becomes easily affected by all kinds of diseases, including fungal diseases.
Compliance with the temperature, humidity and watering regime will help to grow a decent crop of tomatoes.
Preparations against gray rot
Treatments for tomato gray rot are well established. However, they are often used late, which significantly affects efficiency. The most frequently undertaken measures are not effective enough due to an incorrect diagnosis of pathology.
An integrated approach should be taken for plant protection. The most important thing is the timely identification of the primary foci of the disease. Particular attention must be paid to the careful handling of plants.: this will reduce the likelihood of wounds through which the infectious agent easily infects tomatoes.
During the growing season, it is necessary to regularly inspect the plants in order to identify the first signs of gray rot. Particular attention should be paid to this work when breaking off leaves in wet weather.... If you find foci of the disease, coat the tomatoes with a paste with fungicides. The general processing of plants is carried out if there was no thorough coating of the fruits at the time of the onset of the disease. For continuous treatment, experienced gardeners recommend the use of Topsin M, Bayleton, Euparen multi.
Growth regulators... The use of sodium humate during the growing season significantly reduces the likelihood of the development and mass spread of gray rot.
Biological products... Preventive treatment of plants with a Trichodermin suspension, especially after breaking off leaves, greatly minimizes the development of repeated foci of infection. The same purpose is served by smearing wet spots with a suspension of Trichodermin, Glyocladin. The method is time consuming, but very effective. It is also recommended to spray new cuts of leaf petioles with Trichodermin when they are massively removed. Process the tomatoes during the day to allow them to dry.
There are no hybrids resistant to gray rot of tomatoes, F1 Pilgrim and F1 Vasilievna are tolerant.
Preventive actions
Any disease is easier to prevent than to cure. This statement fully applies to tomatoes. Compliance with agrotechnical requirements for growing tomatoes will help to grow, harvest and maintain a decent harvest. What should you pay attention to?
- Balance mineral fertilizers.
- Accurate handling of plants... Broken twigs can cause disease.
- Soil mulching, which will affect its properties and will not dry out.
- Hypothermia protection during planting.
- Plant protection against unsuitable weather conditions(disembarkation in greenhouse conditions).
- Maintaining the optimal distance between plants for the sufficiency of their receipt of useful substances.
- Timely and thorough soil disinfection.
- Choice and seed processing.
Conclusion
Any kind of rot is very dangerous. She is able to completely destroy the grown crop. Little of, rot is easily transmitted in a short time from one crop to another... In order to avoid unpleasant consequences, take care of the prevention of this disease.