Black apple cancer treatment methods

Recently, gardeners have increasingly begun to notice such a disease as black cancer on their fruit trees. Most often, this disease affects exactly apple trees (in second place are pears). Apple tree cancer can infect large gardens. Black apple cancer is considered a dangerous disease that can seriously damage fruit trees, up to their death.

What is Black Cancer?

Black apple cancer or "antonov fire" is a dangerous fungal disease that is almost ubiquitous. This disease is especially common in the southern, northern and central regions (most often found in the southern regions). Also, black cancer is often diagnosed in areas where sharp fluctuations in air temperature often occur, especially in the autumn period.

It is believed that this apple cancer affects weakened trees and its development is caused by faulty agricultural technology, damage by various pests and diseases (especially stem), as well as the presence of frost-sunburn. But when a healthy apple tree is infected, there is a possibility of self-healing.

Quite often, this disease affects fruit trees that grow on loamy heavy soils, where there is an excess of moisture. Outbreaks of black cancer occur after a bountiful fertile year.

The causative agent that causes this disease is the fungus Sphaeropsis malorum. The fungus reproduces by spores, which are released by pycnidia in wet weather. The spores disperse and travel to healthy areas of the tree, infecting it. Infection of an apple tree occurs in the temperature range from +3 to +40, and the most favorable temperature for infecting a tree is +22 - + 28. It is under these conditions that the spores of the fungus germinate after about 6 hours. At a lower temperature, the spore requires up to a day to grow. On a tree, spores can persist for up to two years.

This type of fungus can infect fruits, leaves, stem bark, as well as skeletal branches. A photo showing this fungus is shown below.

Of all the possible lesions, the most dangerous is tree bark infection. In this case, apple trees begin to bear fruit poorly.

Trees affected by this disease appear charred. It is because of its appearance that the black cancer got its second name - "Antonov fire". A large number of affected areas on the bark and skeletal leaves leads to rapid drying of the leaves and indicates the imminent death of the apple tree. The death of a fruit tree, if nothing is done and not treated, occurs within a couple of years (approximately 3-4 years).

The disease has virtually asymptomatic onset. Later, the following symptoms of the disease appear on the tree:

• rounded brownish depressions in the form of spots are formed on the bark, which practically do not attract attention;
• in the future, in place of these spots, a sooty black bloom forms;
• after a short period of time (may be very short), the affected area begins to "char";
• healthy bark, as a result of increased tissue growth, rises at the edges of the spot;
• a gap forms on the border between the diseased and healthy bark, which leads to the formation of cracks;
• cracks are located in areas surrounding the site of the disease;
• in the future, large cracks are formed on the bark, as a result, it exfoliates and the wood is exposed;
• bare wood begins to turn black quickly;
• over time, the state of the bark of the apple tree worsens.

Sawing off damaged branches gives only a temporary improvement and most often it all ends with uprooting the fruit tree.

In the photo below you can see how apple trees look like, affected by black cancer.

When flowers, leaves and fruits are affected, similar symptoms are observed as when the bark is infected. The course of the disease is best seen on the leaves.

Symptoms of black apple cancer on leaves:

• reddish or brownish-brown spots appear on the foliage;
• they are formed after bud break;
• at the beginning of the disease, the spots are small and scattered over the entire surface of the leaf;
• spots, reaching a size of 6 mm, begin to turn brown;
• the spot may outwardly resemble a blade;
• a gray part forms in the center of the spot;
• the stain begins to blur;
• the gray part of the spot even fills the space between the leaf veins;
• then new spots appear;
• spots seem to come out of one another;
• the disease affects the entire leaf blade.

As a result, the leaf dries up prematurely, and it falls off. Leaf fall begins two months before the fruit ripens. After it, there is a noticeable decrease in the quality of the fruit.

The disease of the fetus also has a similar picture:

• fruit damage occurs before ripening;
• dark subcutaneous spots form on the fruits;
• the damage spreads from the place of damage by insects;
• spots quickly spread over the entire surface of the apple;
• then darkening of the pulp occurs;
• the fruit takes on a wrinkled appearance and dries out rather quickly;
• on apples, black cancer takes the form of black rot.

A distinctive feature of the development of infection on fruits is the color of the spots (brown or dull black) and a noticeable roughness. This can be clearly seen in the photo below.

Also, cancer affects ovaries and unripe fruits, even those that are in storage.

Flowers that are affected by a fungus look like those burnt by fire. Their petals turn brown and begin to curl. The pistil and stamen turn black.

It is known that the causative agent of black apple cancer can survive the winter, hibernating in its bark, as well as in other infected areas. If you suspect this disease, you can use a magnifying glass to examine the tree. If there is a fungus on the apple tree, then small dots that are located around the ulcers will be clearly visible in the magnifying glass. These spots are called pycnidia. In them, the spores of the pathogen (pathogenic fungus) mature. Pycnidia are laid under the upper skin. It bursts at the time of the maturation of the spores. It is the presence of pycnidia that is an accurate sign of black cancer.

Video "Black crayfish of fruit trees"

You can find out more information about this infection in this video.

How to prevent

In order to prevent infection of the apple tree with this dangerous disease, preventive measures should be taken. Control measures for this disease include the following:

• in autumn and spring, it is necessary to carefully clean the bark from fruit trees with iron brushes;
• all the dust that has formed after peeling off the bark must be burned;
• timely carry out all the necessary sanitary and preventive measures, which include pruning trees, tying young apple trees, pest control through collective processing and spraying with biological products, cutting dry and diseased branches;
• in addition to pest control, do not forget about carrying out preventive procedures to avoid infection of the apple tree with other diseases;
• monitor the correct care;
• carry out enhanced weed control throughout the season;
• prevention of frost and sunburn, as well as cracks in the bark. To do this, whitewash the boles, as well as the bases of the skeletal branches on the apple tree.

In order to carry out all the preventive procedures correctly, you must first know about all the necessary measures and prepare for them in advance.

You can also plant varieties of apple trees in your garden in advance that have increased resistance to this disease: Cinnamon striped, Borovinka, Pepin saffron and Papirovka.

One simple rule should be remembered - in order for your garden to produce a high-quality and large harvest, preventive measures are required, since it is much easier to prevent a disease than to cure it.

How to cure

However, preventive measures are not a panacea, they do not give a 100% result, and the apple tree can still become infected with this dangerous disease. In this situation, it is necessary to properly treat the tree in order to most effectively and completely defeat this ailment. Therefore, the question naturally arises: how to properly treat an already infected tree?

In order to treat black apple cancer, you need to do the following procedures:

• treatment must begin with the gentle removal of bark and branches that are severely affected by cancer;
• all the resulting wounds and wounds must be lubricated with linseed oil or oil paint based on it. Also, wounds can be treated with garden varnish, pharmacy brilliant green or paint. This process is shown in the photo below;

• then it is necessary to begin to heal the remaining, intact part of the tree. cleaning of the affected fragments is carried out;
• disinfection is carried out with a solution of copper sulfate. Other preparations are also suitable, but they must necessarily contain copper in their composition;
• as a disinfectant, without cleaning the tree, you can use a strong solution of potassium permanganate. They need to thoroughly wash the entire trunk and branches;
• also for disinfection, you can use a saturated solution with table salt, to which a couple of drops of iodine are added beforehand;
• sometimes you can find information that ordinary washing powder was also used as a disinfectant material;
• experienced gardeners suggest treating the tree with physiological putty after stripping, which is prepared from fresh mullein and clay in a 1: 1 ratio;
• leaves affected by cancer after flowering are treated with Bordeaux liquid;
• the affected branches, bark and leaves are destroyed. They are collected and burned.

The process of treating infected apple trees is clearly visible in the video posted above.

Black cancer is a dangerous disease for the apple tree, neglect of prevention and treatment is fraught with the loss of a whole tree, which could grow for a long time and give good yields. The process of treating black apple cancer requires a responsible and attentive approach.