Cabbage has black stems - why and what to do?

One of the most dangerous cabbage diseases is blackleg, which can destroy a large number of seedlings. To prevent widespread infection, it's important to take preventative measures and know how to combat the disease. The disease is caused by a fungus, whose spores are found in the soil and can overwinter there.

When planting, the fungus attacks the root zone and stem of the plant, causing the seedlings to become thin, the stem to break, and they to die.

Reasons

Under favorable conditions, fungal spores multiply very quickly. There are many factors that contribute to the active spread of infection, including:

• ignoring crop rotation rules;
• increased soil moisture levels;
• rainy summer;
• elevated soil pH;
• oversaturation with nitrogen fertilizers;
• small distance between bushes;
• dry, air-impermeable soil;

The spread of the disease can also be facilitated by insufficient lighting and damage to the roots or above-ground parts of plants.

Symptoms

The disease attacks seedlings at various stages of development. Blackleg can affect both seedlings and seeds at the germination stage, as well as established plants planted in contaminated soil. In the former case, there is almost no chance of saving the seedlings. The roots of young plants have a watery structure; after a while, they begin to rot, and the weak shoots bend to the ground and die.

Cabbage planted in contaminated soil experiences thinning and blackening of the root collar. As a result, the stem begins to dry out, which can lead to stunted seedling development. Cabbage heads often form, but these will rot. If cabbage is infected in the final stages of growth, dull and wilted foliage is observed, along with the appearance of fungal sclerotia.

Prevention

Preventing blackleg is much easier than treating it later. You can plant varieties resistant to this disease, such as "Kazachok." The following varieties are susceptible to blackleg:

• Glory;
• Number one;
• Belarusian 455;
• Amager 611;
• Moscow late;

Seed preparation

Before planting, seeds must be treated, as pathogens can overwinter in them. Planriz has proven effective; a 1% solution is applied to the seeds 24 hours before planting. Some gardeners soak the seeds for 2 hours in a solution of Fitosporin-M, dissolved in water at a rate of 4 drops per 200 ml of water. Seeds can also be disinfected using:

• Barrier;
• Baktofit;
• Pseudobacteria;
• Phytoflavin-300;

After treatment, the seeds are warmed in hot water at 50 degrees Celsius. This procedure will protect the seeds and sprouts.

Soil

Since fungal spores can be present in the soil, it must be disinfected before sowing. This should be done approximately two weeks before planting. There are several ways to eliminate pathogenic flora in the soil:

1. Steaming in a water bath.
2. Calcination in the oven at 100 degrees for 30-40 minutes.
3. Pouring boiling water or a hot solution of potassium permanganate.

The soil in a garden bed or greenhouse can be disinfected with colloidal sulfur; 5 grams per square meter is sufficient. Some use wood ash (100 grams per square meter); it regulates soil acidity and protects cabbage from blackleg. You can also water the soil with a 1% solution of Bordeaux mixture, manganese, or copper sulfate. In addition to these common remedies, there are special preparations for combating harmful bacteria and fungi. The most popular are Trichodermin and Barrier.

Treatment

Disease control must be drastic: affected seedlings are destroyed, the soil from the holes is removed and disinfected with a solution of potassium permanganate or copper sulfate. To kill any remaining fungal spores in the soil and prevent infection of the remaining seedlings, special products are used:

Fitosporin-M

Preparation and use:

Dissolve six grams of powder in a bucket of room-temperature water and let it steep for 1-2 hours, stirring occasionally. Spray the above-ground parts of plants with the resulting liquid in the morning or evening.

"Previkur Energy"

Dilute 25 ml of the concentrated solution in 10 liters of settled water. Apply the solution to the leaves of young plants. Apply 3-4 times depending on the severity of the infestation.

Seedlings can also be watered with a 0.5% solution of potassium permanganate, soda or 1% Bordeaux mixture.

Grown seedlings can be treated and can be left in place. However, such cabbage is not suitable for storage. At the first signs of disease, the plants should be watered with potassium permanganate and the soil should be sprinkled with wood ash. Some gardeners recommend burying a tablet of "Gliokardin" under the roots.

What to do if cabbage is re-infested

If the disease reoccurs, you can help the plants by taking the following measures:

• bury a gliclazide tablet at a depth of 1 cm;
• regularly loosen the soil and hill up the bushes;
• water the roots with a weak solution of potassium permanganate;
• sprinkle the soil with ash;
• Treat the plants with a solution of "Trichodermin", prepared from 100 ml of the substance and 10 liters of settled water, the treatment is carried out in cloudy, cool weather; in case of a large area of ​​infection, the treatment is carried out at least 5 times;

Helpful tips

1. In the initial stages, you can use folk remedies, for example, an infusion of onion peels.
2. The soil for cabbage should be loose, moisture-retentive and well-aerated.
3. Avoid planting too densely, as this will promote the development of the disease.
4. When transplanting seedlings that become diseased before planting, they are planted so that the darkened part is underground.
5. Plants that come into contact with the source of infection are quite difficult to treat; the most effective drug in this case is considered to be "Baktofit".
6. Compliance with agricultural technology is the best means of preventing diseases and pests.

Conclusion

Blackleg is a disease that can destroy seedlings in the early stages of development, but it's less dangerous for established plants. To protect cabbage from this scourge, it's important to follow proper agricultural practices and thoroughly disinfect containers, soil, and seedlings.