Methods for the treatment of root rot of tomatoes - "black leg"

Root rot of tomatoes is triggered by a fungus and develops when certain conditions are created. The people call this disease "black leg". The disease often affects young seedlings, which quickly die as a result. The culprits of root rot are fungi of the genus Olpidium or Pythium, whose spores are extremely common and are found in the topsoil. The fight against the "black leg" must be started immediately.

Root rot symptoms

At significant humidity and elevated temperatures, the mycelium begins to multiply actively. Fungi switch to feeding on tissues of living plants - organic particles present in the soil are no longer enough for them.

Symptoms of root rot damage appear early in the development of tomatoes, even before the leaves open. The lower part of the stem, adjacent to the root collar, blackens and becomes thinner.

The rot quickly spreads to the entire lower part of the seedling, it ceases to receive nutrition and dies. Due to the "black leg", seedlings can disappear in just a few days. At the last stage of the disease, the seedlings lie on the ground, where their final decomposition takes place.

Factors contributing to the development of the disease

Despite the prevalence of the fungus, tomato root rot occurs only with the combined effect of certain factors.

The mycelium enters the active phase under the following conditions:

• soil moisture over 90%;
• increased acidity of the soil;
• non-compliance with the temperature regime;
• a sharp change in growing conditions;
• excessive planting density;
• refusal to disinfect the soil;
• low quality seeds;
• insufficient lighting.

The disease develops rapidly and is almost impossible to treat. Control measures should be aimed primarily at preventing root rot. You can also avoid the disease if you buy tomato seeds that are resistant to the "black leg" for planting.

Control methods

Root rot treatment can only be successful at the onset of the disease.

Experts recommend first removing individual affected seedlings - this will help save the rest of the seedlings. Sick plants are pulled out and thrown away, they are too small to recover, and in the future they still will not give a full harvest.

At the first signs of illness, it is necessary to adjust the care of the seedlings and carry out the appropriate processing:

1. Watering tomatoes is temporarily stopped.
2. If the plantings are too dense, they must be thinned out.
3. Be sure to remove all weakened and disease-bearing seedlings.
4. The earth is loosened and disinfected using a 1% solution of Bordeaux liquid or copper sulfate. You can replace these funds with a weakly saturated solution of potassium permanganate.
5. The seedlings themselves are treated with biological preparations such as "Trichodermin", "Fitolavin", "Fitosporin-M". After 10 days, the seedlings must be sprayed again.

Application of fungicides

In case of mass damage to seedlings, chemical fungicides are used at the initial stage, which have a more powerful effect. These agents act directly on fungi and fungal spores, disrupting their vital functions.

Fungicides decompose rather quickly and do not pose a threat to soil and plants in the future.

Effective drugs to combat the "black leg":

• Ridomil Gold;
• colloidal sulfur;
• "Tiovit Jet";
• Fundazol.

During the preparation of the working solution and the treatment, it is necessary to use protective equipment (mask, rubber gloves, glasses).After spraying the seedlings, ventilate the room and leave it for a while. The drug should be used in the dosage recommended by the manufacturer.

Using folk remedies

By themselves, folk remedies in the fight against root rot of tomatoes are insufficiently effective, but they can be used as part of a comprehensive treatment along with chemicals.

To destroy the "black leg" use:

• Infusion of onion peels. For its preparation, a liter jar of husk is poured with 2 liters of hot water, insisted for two days and filtered. Before use, the infusion is diluted with water in a ratio of 1: 2. Spraying is carried out 2 times a week.
• Vodka. The method is easy to use. Vodka is diluted with water in a ratio of 1:10 and sprayed on the aerial part of the seedlings. The alcohol contained in such a solution has a detrimental effect on the fungus.
• Potassium permanganate solution. Potassium permanganate crystals are known for their disinfecting properties. A weak solution of pale pink color is suitable for treatment. They moisten the soil with it and process the lower part of the stems of the seedlings.
• Chalk and wood ash. Both components are ground into powder, and then mixed in equal parts and powdered with a mixture of the root zone of the tomato stem. A little powder can be sprinkled on the ground near each seedling.
• Iodine solution. The working solution is prepared from a pharmacy iodine tincture and water in a ratio of 1: 4. The finished product is moistened with the upper roots of tomatoes and the lower part of the stalks.

If the foci of the disease are too extensive, the tomatoes are dived and transplanted into a new sterile substrate. Before planting, the roots of the seedlings are soaked for 2 minutes in a solution of "Baktofit" of 0.5% concentration.

If the treatment did not help, and for some reason it is not possible to sow the seeds again, the seedlings are re-rooted. In each seedling, a razor blade is used to cut the stem 5 mm above the lesion site with the "black leg" and place the plant in water so that the leaves do not touch the water surface. After 10 days, the tomatoes will develop new roots and can be re-planted in the ground.

Preventive measures

To reduce the risk of root rot, the following guidelines are recommended:

• Carry out pre-sowing disinfection of seeds and disinfection of soil.
• The seedling soil should have an acidity closer to neutral.
• Seed material should be purchased from a reliable supplier, choosing varieties that are resistant to fungal infections.
• It is advisable to germinate seeds in peat cups so that the roots can breathe.
• The film used to create greenhouse conditions is lifted daily for ventilation and condensation is removed from it.
• It is necessary to water the seedlings so that there is no stagnation of water, the soil should dry out between waterings.
• A small mound of dry sand is poured at the base of each seedling.

Root rot of tomatoes is a formidable disease that can completely "mow" seedlings. To avoid adversity, you should initially create optimal conditions for tomatoes and provide suitable care. Treatment of the disease will be effective only if it is possible to capture its onset.