Cracks in the bark of an apple tree are usually a concern for gardeners. If you do not start to deal with them in time, there is a possibility of not only reducing the yield, but also the death of the tree. In addition, the disease can very quickly spread to other fruit trees, affecting most of the garden.
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The causes of cracks
Cracks in the bark may indicate the presence of fungal infection, cancer, cytosporosis, pathogenic bacteria, pest attack, podoprevanie or sunburn. The most dangerous cracks are those that have arisen from oncology. This disease is very difficult to treat. The tree can only be saved if the disease is detected in the early stages.
Fungal infection
The apple tree from time to time is affected by pathogenic fungi, which provoke the appearance of cracks. The fungus can appear due to dampness during warming. To cope with a fungal infection, fungicides or Bordeaux liquid are used.
Crayfish
The apple tree can be affected by two types of cancer:
- black (antonov fire);
- nectaria - open or European.
In the case of black cancer, the disease progresses very quickly and harmful. A diseased tree can die within the first four years if left untreated. The disease enters plant tissues through freezing holes, cuts and breaks.
Black cancer occurs due to fungal colonies. They can be identified by their characteristic brown grooves and dark bloom. They ring the trunk, as well as the places where large branches bifurcate.
Then, on the surface of the bark, a large number of black bumps appear, resembling "goose bumps". The bark of the tree begins to crack and flake off, resulting in dark and deep wounds that extend to the core of the tree.
Common cancer develops much more slowly. Reddish growths and bumps appear around deep cracks. This type of cancer affects the trunk, skeletal and lateral branches. The dying off of the bark and the wood itself begins, due to which the protective functions of the apple tree decrease. This negatively affects the quantity and quality of the crop. If the tree is badly damaged, there are disruptions in the carbohydrate and water balance. It starts to fade. The first symptoms of the disease are most often seen during a thaw.
Cytosporosis
Cytosporosis is a fungal infectious disease due to which branches dry out. Shoots cannot receive sufficient amounts of nutrients, since sap flow occurs only in the bark. Fungi release toxins, under the influence of which the bark of the tree becomes rough and begins to dry out, juices stop flowing through it. At first, it becomes dark, then dies off along with the shoots.
The source of infection is usually various injuries, for example, cuts, hollows, small open cracks, ultraviolet burns or frostbite. The fungus gets into wounds with the wind or is carried by insects. The pathogen overwinters in the form of spores on infected branches. With the arrival of heat, humidity increases greatly, due to which the fungus begins to actively develop. Apple trees are especially prone to infestation in the fall.
Bacterial burn
Bacteria spread throughout the tree along with the movement of cell sap. And they penetrate into the plant through wounds that have gotten pollen from an infected crop. Flowers and young green branches begin to dry out very quickly.
The bark is covered with cracks, from which a sticky whitish liquid is released. Then this liquid gradually darkens.
Dead red cambium can be seen through the cracks. Individual shoots and even the entire plant die within a couple of years.
In some cases, the plant can be saved, but only in the initial stages of the disease. To do this, you need to cut off the affected branches with a disinfected tool. Additionally, it is necessary to spray the apple trees with a solution of "Fitolavin" or the antibiotic "Ampicillin". The spraying procedure is carried out 5 times during the growing season.
Frost damage and sunburn
Such damage manifests itself in the form of cracks and necrosis in the bark. In some cases, wood is also affected. Such lesions appear due to severe frosts or sudden temperature changes.
In early spring, the sun's rays quickly warm up the dark trunks, reflecting off the snow. And night frosts cool the plant. This leads to tissue deformation and partial death. As a result, the crust flakes off.
Planting winter-hardy apple varieties is considered the best preventive measure. But if the wounds have already appeared, then they need to be treated with an antiseptic and covered with garden varnish.
Underpinning
The bark supports in those cases when by the arrival of autumn the tree tissues have not yet fully matured. In winter, they are destroyed by moisture and sudden changes in weather. In certain cases, the reason is a weak rootstock or too much snow cover.
Often, only young trees or seedlings are supported. When the bark begins to dry out, it departs from the trunk in a circular manner. After the onset of stable heat, the damaged apple tree can bloom thanks to the supply of nutrients. But the juices stop coming from the root system. The tree dries up gradually.
If the pathological process was detected at the initial stages, the plant can be tried to be saved by grafting.
Sapwood beetles
The sapwood is a reddish bark beetle. On average, its size is about 4 mm. The parasite attacks weakened plants, but in some cases it also settles on healthy apple trees.
The presence of an insect can be detected by the presence of small round holes. With extensive damage to the tree by the pest, cracks appear.
Carpenter butterflies
The larvae of this insect live in the wood of the apple tree. They gnaw their holes in the internal tissues. This leads to a malnutrition of the cells of the tree. Damaged branches gradually lose strength and elasticity, they easily break under the influence of wind.
Severe damage by larvae leads to the death of the tree. Among the signs of the presence of pests, the presence of red wormholes on the bark is distinguished. Caterpillars begin to attack apple trees in spring, when the air temperature rises to +10 degrees.
Bark beetles
The bark beetle is a very dangerous pest for any fruit tree. With mass reproduction, it is able to destroy even a strong adult apple tree in just a couple of months.
When damaged by a bark beetle, the plant is dehydrated. In one summer, it can dry out completely.
Apple tree treatment
There are many reasons for bark cracking. If there is little damage, then the tree often copes with the problem on its own and continues to bear fruit. But a large amount of damage can lead to the death of the plant. In these cases, it is necessary to carry out certain manipulations aimed at saving him.
The damaged areas are treated with a disinfected instrument. It should be cleaned carefully so as not to damage healthy areas.
After stripping, the affected areas are treated with potassium permanganate, hydrogen peroxide or brilliant green. Then these areas are covered with garden varnish and wrapped with opaque polyethylene. Instead of film, you can use burlap or other thick fabric.
The removed parts of the plant should be removed from the site. It is advisable to burn them.
Rescue of an old apple tree
Trees, like all living organisms, are gradually aging. Over time, they also start to hurt. One of the typical diseases in old apple trees is cracking of the bark.
Depending on the scale of the lesion, you can perform certain manipulations to save your favorite plant:
- If the lesions are not too large, then you can remove all the lagging bark with the help of a disinfected metal brush.
- All pests will be removed along with it.
- Then you need to whitewash the cleaned places. For this, a thick solution of lime is used. You can additionally add mullein to the lime. This will make the plant more resistant to disease.
If large areas are damaged, the affected branches are cut down. The saw cut must be treated with an antiseptic and covered with garden pitch to prevent the appearance of pests and fungal diseases.
Do you know why the bark of an apple tree cracks?
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