by Cabbage is grown by all summer residents. It is a very useful vegetable, but at the same time quite unpretentious in care. However, it sometimes makes gardeners nervous: either caterpillars or slugs gnaw the leaves, or cruciferous flea beetles attack, or suddenly healthy heads of cabbage begin to rot from the inside.
The last problem is especially dangerous because it can only be discovered when it is no longer possible to help the head of cabbage.
Why does rot appear inside the head of cabbage? The reason is most often one of the most dangerous cabbage diseases – mucous bacteriosis, which is also called wet rot.
Causes of mucous bacteriosis
The causative agents of mucous bacteriosis are bacteria of the genus Erwinia. The disease affects cabbage of different species. This occurs mainly in the second half of the growing season and during storage. Most often, cabbage of early, mid-early and mid-season varieties becomes the victim of pathogenic bacteria.
Sources of infection may include unharvested plant debris, infected weeds, water from natural reservoirs used for irrigation, as well as insect pests – cabbage flies, bugs, cruciferous flea beetles, etc.
Often the disease occurs due to excess nitrogen fertilizers. Under the influence of nitrogen, cabbage leaves grow huge, but at the same time they do not have a dense, but a loose structure, due to which pathogenic microorganisms easily penetrate inside.
Hot (25-28°C) and humid weather also contributes to the active development of the pathogen, so in a warm rainy summer the harvest suffers more from wet rot. Weakened plants with mechanical damage are most susceptible to slimy bacteriosis.
Signs of cabbage slimy bacteriosis
There are two variants of development of wet rot.
1. The disease starts from the top, from the outer leaves. They become dark, covered with oily spots, which gradually increase in size, covering the entire leaf. A rotten smell appears. Over time, the disease spreads to the entire head of cabbage, which eventually leads to its spoilage.
2. The spread of mucous bacteriosis begins from the bottom, from the cabbage stump. Pathogens penetrate the plant from the soil. As a result of the infection, the cabbage stump becomes darker, acquires a creamy-gray shade and softens. The disease progresses quickly, affecting the entire head of cabbage. Just like in the previous variant, an unpleasant putrid smell appears. Sometimes, signs of the disease are not visible from the outside at all – the rot inside can be noticed only after cutting. Because of the soft cabbage stump, the head of cabbage simply falls over time.
It is difficult to detect the appearance of wet rot at the initial stage and during storage of cabbage: inside the head of cabbage is already rotting and gradually turning into a slimy mass, and on the outside it still looks quite healthy. The damage can be noticed during this period only by the smell of rot.
How to combat mucous bacteriosis
There is no treatment for mucous bacteriosis. If you have detected the disease at the earliest stage, the head of cabbage can still be used: remove the affected leaves and a few healthy ones, and try to eat the rest as quickly as possible, and only after heat treatment. If the disease has gotten inside the head of cabbage, it can no longer be used for cooking: remove the plant from the garden bed, take it outside the area and burn it.
Only compliance with preventive measures and rules for growing the crop will help protect cabbage plantings from slimy bacteriosis.
1. Crop rotation: you cannot grow cabbage in the same bed two years in a row or plant it immediately after other crops of the cruciferous family (turnips, radishes, horseradish, mustard, horseradish). The crop can be returned to its previous place only after four years. The best predecessors for cabbage are legumes, onions, garlic, tomatoes, peppers and potatoes.
2. Moderation in feeding: to avoid excess nitrogen fertilizers, apply them only at the very beginning of the growing season, then replace them with potassium and phosphorus fertilizers. It will also be useful to add a handful of wood ash to each hole when planting. This natural fertilizer will not only saturate the soil with potassium, phosphorus and essential microelements, but also reduce the acidity of the soil, which will help prevent the development of another dangerous cabbage disease – clubroot.
3. Maintaining the distance between plants: the probability of being affected by mucous bacteriosis increases if agricultural practices are not followed, in particular if plantings are too dense. In such a situation, air circulation is disrupted, the water on the leaves does not dry for a long time, which contributes to the active spread of wet rot.
4. Preventive treatments must be carried out at all stages of growing cabbage. Seeds and seedlings are treated with biopreparations based on hay bacillus (for example, Fitosporin-M) or trichoderma (for example, Sporobacterin). After the fifth leaf appears, the plantings are sprayed with a solution of Gamair. During the period of active growth, treatment with biopreparations (Sporobacterin can be used again) is carried out every 15-20 days.
5. Pest protection is also extremely important, because caterpillars gnaw cabbage leaves, causing mechanical damage and weakening the plant, insects can become carriers of the disease. To reduce the likelihood of being affected by mucous bacteriosis, inspect the plantings for pests throughout the growing season and immediately begin to fight the insects at their first appearance.
6. Growing disease-resistant varieties: varieties and hybrids that are not susceptible to the disease mucous bacteriosis have not yet been bred. However, the likelihood of infection will be lower if you grow cabbage that is resistant to most diseases – for example, such varieties and hybrids as: Airbus F1, Snow White, Galaxy F1, Kazachok F1, Kolobok F1, Mara, Gift.
7. Timely harvesting: Contrary to popular belief, cabbage should be harvested not after the first frosts, but before them, since slimy bacteriosis often affects frozen cabbage during storage.
Follow agricultural practices, do not allow mechanical damage to heads of cabbage, cover the plantings with film during periods of prolonged rain, send only completely whole and healthy heads of cabbage for storage – and the likelihood of the appearance of slimy bacteriosis on your site will be reduced to a minimum.
