Black leg in tomatoes: why did it appear and what to do?
Each owner is looking forward to the moment when he sees the first shoots of the seeds sown by him. With bated breath, he watches the growth of seedlings and their transformation into beautiful, strong, full-fledged seedlings. However, sometimes it happens that this fascinating process is overshadowed by plant diseases. One of the most common problems in tomato cultivation is black leg disease.
In order not to lose all the seedlings, you need to understand the causes, remember the symptoms and ways to deal with this disease. It will not be superfluous to find out as much as possible about him.
What it is?
The disease of seedlings and tomato bushes, popularly known as the black leg, is nothing more than an infection of a plant with pathogenic fungal microorganisms. An inexperienced gardener can easily not notice a problem in the initial stages of its development, and after just a few days, lose all the plants on the site. Such a bitter fate can be avoided with a little effort. Therefore, it is very important to monitor the condition of seedlings, especially after transplanting them into open soil. And knowing a few elementary rules and secrets will help to completely avoid this trouble.
signs
The disease of the blackleg has bright, characteristic signs and a certain sequence of manifestations on the plant. Knowing these signs, you can save healthy seedlings from infection with a fungus. Consider the order of its impact on seedlings.
- Darkening of the base of the stem. The first sign can be seen immediately after germination. If the bottom of the stem is painted dark gray or black, the plant is almost certainly sick.
- Stop development. The infected plant stops growing, the leaves are difficult to form, they are weak.
- The darkening of the stem spreads upwards, the metabolic processes in the plant slow down significantly.
- The resulting leaves curl and dry out.
- The base of the stem becomes thin, knotty and completely black. During this period, moisture and nutrients finally cease to flow into the upper part of the tomato bush.
- The plant breaks, falls and continues to dry out and decompose, infecting the entire environment.
- At the end of the development of the disease, the plant looks like a thin black thread.
The black leg is most often found on seedlings. Young plants are still unable to resist fungal infections on their own, while adult plants, on the contrary, develop immunity to this disease and are much less susceptible to it.
In the case of seedlings, it may take only a few days from the moment of infection to the complete death of the plant.
The reasons
A fungus is a living organism that needs a suitable habitat for development and reproduction. Tomato seedling boxes often harbor pathogenic microbes for several common reasons. The main reason can be safely considered the increased acidity of the soil. Such soil is in itself an ideal breeding ground for fungus. If you add too frequent watering to such soil, you get the effect of a warm, cozy swamp in which the fungus multiplies at cosmic speed.
Fungal organisms do not tolerate the sun's rays very well, so seedlings growing in good light are much less likely to get blackleg than low-light seedlings.
Low indoor temperatures slow down the process of water exchange in the soil. This leads to constant excess moisture, which is also beneficial for fungal diseases, so it is very important that the seedlings are kept warm.
Seedlings that are too dense also create constant shade and dampness at the base of the stems, which is why it is important to thin them out.
If you follow the simple rules for keeping seedlings: light, warm, humid, but not wet, you can easily avoid the development of a blackleg at all.
How to fight?
You need to understand that the fight against the black leg is a laborious and inefficient process. And you also need to accept the fact that plants that have recovered from this disease will be so weak that they are unlikely to be able to produce at least some kind of crop, so it makes no sense to treat it. Given the above facts, the most correct thing will be to perform several sequential actions.
- When the first symptoms of infection are detected, it is important to get rid of all suspicious plants. It is important to remove the plant completely along with the roots, since the blackleg is very contagious - the affected remains of the plant are dangerous for healthy seedlings.
- Since the treatment process is mainly cultivating the land, too thick seedlings will interfere, so the next thing to do is to thin out the seedlings. It is not at all necessary to throw out the "extra" sprouts, they can be planted in a new sterile container with cleaned soil.
- Next, it is important to disinfect the soil with high quality.To do this, the soil must be loosened and carefully sprayed with a one percent solution of manganese. You can also use a formalin solution, but after processing it is necessary to loosen the soil several times so that all the formalin evaporates.
- The stems and roots of healthy plants should be treated with special antifungal drugs called biological fungicides. In the fight against the blackleg, the drugs "Fitolavin" and "Fitosporin" are recognized as the most effective. This part of the treatment is optional, subject to the qualitative implementation of the remaining points.
- After that, it is important to stop watering for 3 days in hot conditions or 5-7 in cool ones.
- The surface of the earth can be sprinkled with charcoal ash - this will make it unsuitable for the re-development of the disease.
- The final stage of treatment will be transplanting seedlings into a new soil. Plants can be planted immediately in the garden or in other sterile containers. When diving (transplanting to another container), it is better to choose containers with a large number of cells so that each bush grows separately. The container and the ground must be disinfected before transplanting.
After all these measures, it is important to properly organize the watering of plants. It is necessary to water abundantly with water at room temperature only in the morning. This will allow water to saturate the plant faster, and its excess will not linger in the ground and will not become a beneficial environment for the re-development of the fungus.
Folk recipes
Almost every disease has its own folk remedy for treatment. Since the black leg is a plant disease, folk wisdom has not bypassed it either.The effectiveness of such methods of treatment is controversial and has not been proven, therefore it is better to use them in combination with generally recognized drugs as a complex therapy.
The most popular folk remedy is an alcoholic lotion. For her, you will need to dilute vodka with water in a ratio of 1: 10 or alcohol in a ratio of 1: 25. The resulting solution should be sprayed on the affected areas of plants 1 time per day.
Another alcohol-based recipe is the treatment of affected areas of the earth with tincture of onion peel. To do this, pour dry onion peel with a glass of vodka, cover tightly and keep this mixture in a dark, cool place for several days. The finished tincture can be diluted with water in a ratio of 1: 1 or used in its pure form. This tincture should be sprinkled on the ground after removing diseased plants once a week.
A good helper in the fight against blackleg, according to the people, is wood ash. Coal from burnt wood should be ground into powder and sprinkled on areas of land affected by the fungus.
When using this method, it is important to reduce the frequency of watering so that the ash does not attack the roots of healthy plants too aggressively.
Prevention
Preventive measures against the occurrence of blackleg should begin even during preparation for sowing seeds. The most important and most reliable measure is the right choice of land for the germination of future seedlings. To date, there are special enriched mixtures sold in soda centers.
When buying a mixture, it is important to pay attention to the labeling: the package must necessarily indicate “For seedlings” or, in extreme cases, “Universal”, you should not use mixtures with other purposes, for example, for citrus fruits.Such mixtures are pre-treated with antifungal drugs and enriched with vitamins and minerals that will help grow quality seedlings.
If, nevertheless, a decision is made to germinate seedlings in home soil, it is worth carefully preparing it.
First you need to select the land. If the seeds will be planted in several containers, it is worth taking the land from different parts of the garden - for each container, a portion from a new site. The selected land should be steamed, this can be done in several ways.
- Pour the earth in a thin layer on a sheet (tray), pour plenty of boiling water and dry in the sun, it is better to repeat the procedure several times.
- Pour the earth on a baking sheet, pour water and calcine in the oven for half an hour. Choosing this method, you need to be prepared for the fact that the smell from the earth will be extremely unpleasant.
- Clean up the ground with steam. In a bucket with small holes (according to the principle of a colander), you need to pour the earth into half of its volume. A bucket with a larger capacity should be filled with water to 2/3 of its volume. Put a bucket of earth on top in a bucket of water, and heat them on a potbelly stove until the water has completely evaporated. After the procedure, the ground must be dried.
An important role is played by the correct preparation of containers for growing. Containers for germinating seeds must have holes for the outflow of water, because excess moisture is an excellent environment for the development of the fungus. The container must be spacious - this will not only allow the seedlings to grow stronger, but also prevent the rapid infection of healthy plants in the event of a fungus: the greater the distance between plants, the less chance of infection.
Before planting, it is important to disinfect the containers, for this it is enough to treat them with a solution of manganese or special antifungal drugs and dry them. It is better to choose peat, multi-section containers for seedlings, since they are pre-treated against fungal diseases.
In addition, a separate planting of seeds will significantly reduce the risk of diseases, if it appears, it will serve as a protective barrier against infections.
Preparing tomato seeds is a simple matter: just wrap the seeds in cheesecloth and soak them in a weak solution of manganese or baking soda for 10 minutes. Before planting, the seeds must be dried so that, together with the evaporating moisture, the microscopic particles of manganese or soda remaining on the surface of the seeds evaporate.
For information on how to deal with the black leg, see the following video.