Diseases and harmful insects that damage various vegetable crops are serious problems that vegetable growers often face. Cabbage black leg is the most severe disease that damages the roots and bases of vegetable stems.
The infection that causes it is a fungus. Its spores overwinter in the soil, in the spring they fall on the roots of seedlings planted in open ground and begin to develop. From the roots, this fungus gradually begins to spread throughout the plant.
The symptoms of the disease are as follows: blackness appears first at the base of the shoots, then spreading to the entire stem, which begins to rot, becomes deformed and becomes depleted.As a result, the plant dies. How to prevent diseases from appearing on cabbage? What control measures exist against blackleg if the plant is already affected?
Some information about the disease
This fungus affects not only adult plants, but also seedlings. Blackleg usually appears when the soil in the garden or in containers where vegetable seedlings grow is too wet. When the fungus rises from the roots to the stems, they will become soft within a few days, resulting in the death of the vegetable crop.
The causative agents of blackleg are fungi of the genus Oipidium or Pythium. The spores of these fungi are usually located in the upper part of the soil and feed on dead parts of plants. With increased soil moisture, when the fungus gets on the roots of cultivated plants, infection occurs.
If the disease is not detected in a timely manner, the black leg of seedlings or adult plants will spread to other plantings, as a result all plants may die. It is necessary to start the fight as early as possible in order to get rid of the disease.
A disease can appear in seedlings or adult plants for the following reasons:
- plants are planted too often;
- excess moisture in the soil - plants are watered too much and too often, or groundwater comes too close to the soil surface;
- the room where the seedlings grow is poorly ventilated;
- There is too much difference between day and night air temperatures.
The infection spreads especially quickly when the air temperature is too high or when the premises are poorly ventilated. This fungal disease primarily affects the weakest shoots. It is necessary to prevent excessive soil moisture and to ventilate the room where the seedlings are located and the greenhouses more often.
When choosing cabbage varieties for planting, it is better to pay attention to their resistance to unfavorable climatic conditions.
Prevention measures
Measures to combat this disease should begin with preventive measures to prevent the fungus from entering the soil or to destroy it in the soil before planting seeds or seedlings in such soil. What to do to prevent the development of this disease in seedlings? It turns out that the basic rules of prevention are simple, and even novice gardeners can follow them:
- The soil in which the seed is sown must be disinfected. In winter, it should be frozen well, and before planting the seeds, water the soil with a weak solution of potassium permanganate (can be placed in an oven at 180 °C). Usually, soil mixture for planting vegetable crops is purchased in specialized stores, but it is better to disinfect it before planting seeds. It is desirable that the pH of such soil be neutral. Since many vegetable crops do not tolerate high soil acidity, seedlings in such soils grow frail and are therefore more susceptible to various diseases.
- You should not plant cabbage seeds too often. It is better to try to plant them at a distance of 1 - 1.5 cm immediately than to dive or treat them later.
- Cabbage seedlings should be watered in moderation - the soil should not be too wet. The basic principle of watering is as the top layer dries.
- The soil around the plants should be loose so that oxygen from the air can penetrate to the roots. To prevent water from stagnating in the area of the root collar, there should be a layer of sand on top of the soil.
- The fungus that causes the development of blackleg appears not only when the soil is very moist, but also when the air in the room is stagnant.The room where seedlings are grown should be regularly ventilated.
- Once every 7–8 days, cabbage seedlings should be watered with a solution containing phytosporin. For prevention, you can spray the seedlings with a solution of soda or potassium permanganate.
How to deal with black leg in cabbage
If symptoms have just begun to appear, you should water the soil with a weak solution of potassium permanganate, then carefully loosen the soil around the plants and pour a layer of ash, river sand or finely ground egg shells on top.
What treatment should be carried out at the first signs of the disease and what can be done if the black leg has already appeared on the cabbage?
How do we fight blackleg if the disease has already begun to spread throughout the plant? It turns out that in this case any chemicals and folk remedies will be powerless.
All diseased plants should be removed and destroyed, and healthy seedlings should be transplanted into other containers with disinfected soil.
Conclusion
Black leg in cabbage is one of those diseases that can only be prevented. If the root system has already been infected, it is impossible to save the cabbage. It is important to carry out preventive measures to disinfect soil and seed material, create certain conditions for the growth and development of seedlings in order to eliminate the likelihood of developing this serious disease.
