How you sometimes want to bite off a piece of a delicious apple, bake a juicy fruit in the oven with honey or bake an airy pie. When buying apples at the market or in a store, we do not even suspect how much labor has been invested by gardeners in caring for a fruitful tree.
- What diseases are dangerous for the apple tree?
- How to save an apple tree from black cancer
- The causative agent of black cancer on trees
- Types of tree cancer
What diseases are dangerous for the apple tree?
The apple tree, especially in the old garden, is susceptible to many diseases, some of which can destroy the tree forever:
- Powdery mildew. It is dangerous in that it affects the vital areas of the apple tree. An off-white, flour-like coating appears on shoots, leaves, bark and even buds. The leaves, turning yellow, dry up quickly, the shoots stop growing, the tree gradually fades away. Upon the arrival of winter, the disease slows down, remaining to winter in the affected areas of the apple tree. But with the arrival of spring, the activity of the mycelium is restored.
- Scab. Fungus that infects the leaves of the apple tree. Over time, brown bloom can move to flowers, stalks, a young seedling. In case of illness, the leaves dry quickly and fall off. The disease is not fatal for the plant, however, the scab greatly spoils the quality and appearance of the fruit.
- Cytosporosis. Diseases of the bark of the apple tree. The fungus in the form of dark ulcers affects large areas of the plant, going deeper. With improper care and watering, cytosporosis can kill the plant.
- Fruit rot. Rotten brown spots appear on the fruits of the apple tree, the disease quickly spreads to neighboring apples, making the fruits absolutely inedible.
- Bacterial burn. It affects young seedlings, is a quarantine disease, manifests itself in the form of blackening and a change in the shape of the leaves on the tree. If left untreated, fire blight will spread to all plants in the garden.
- Black apple crayfish. The disease has other names - fire, antonov fire. It affects the entire tree, but infection of the trunks is considered the most dangerous. In this case, the tree may die forever. The fungus enters the heart of the tree through wounds caused by freezing of the plant or sunburn. The disease settles in the bark and rotten apples, where it hibernates, waiting for a good opportunity to resume its destructive properties.
Red-brown spots appear on the bark with black cancer, which become darker in the process of disease progression. The skin of the bark swells, becomes blistered, sags and completely falls off. In the foci of black cancer, the bark becomes rough of the corresponding color - black.
The fruits of the ailing tree are covered with depressed spots. After that, the apple rots and becomes completely black. The fruit is mummified right on the branch and remains in this state on the tree.
How to save an apple tree from black cancer
Young trees do not get black cancer. Most often this mushroom is found in gardens from the age of 20. In order to avoid the appearance of such a disease, young trees should be carefully looked after and thoroughly watered. If the disease has nevertheless seeped into your garden and infected the apple tree, you should take some measures:
- Get rid of diseased branches
- Clean up black cancerous wounds
- Close up the hollows
- Destroy Rotten Fruit
- Check the condition of the tree and cuts every 15-20 days
- Whitewash trunk and branches in spring and autumn
Correct cutting must be done with a sharp, sharpened tool. Slices are made taking into account the capture of 1 - 2 cm of the living area. So, the likelihood of relapse disappears. After cutting, the cut is treated with 1% -3% copper sulfate for disinfection. Then cover with putty.
Even if the tree has recovered, it is not worth grafting cuttings from it. The disease can manifest itself over time. Most of all, apple trees are susceptible to disease in the spring, when it is warm and humid outside. There are known apple varieties that do not suffer from black cancer. These include Papirovka, Cinnamon striped, Pepin saffron, etc.
The causative agent of black cancer on trees
The causative agent of black apple cancer is Sphaeropsis malorum Peck. This fungus belongs to the class Deuteromycetes. Dark brown, often black, pycnidia reach a diameter of 1.5 - 5.5 cm. The unicellular spores of the fungus are colorless. After ripening, they acquire a brown or brown color. Sometimes they also consist of a partition of 24-30x10-12 microns.
It reproduces vegetatively with the help of pyknospores. The source of infection is a spore living in damaged bark and branches. Attacking weakened trees, black cancer is able to destroy the apple tree. Temporary detection of the disease and proper treatment will lead to healing. After the rehabilitation period, the tree will be completely healed.
Black cancer affects more than just the apple tree. Less often, pear and other stone fruit trees fall under its negative impact. The disease manifests itself identically to an apple tree, and is treated in the same way.
Types of tree cancer
In addition to black cancer, fruit trees suffer from common and root cancers.
Common cancer affects the bark of a tree, skeletal branches and branches of the second order. Very rarely, the disease affects the fruits of the plant. When a tree is damaged by low temperatures, wounds are formed, which most often overgrow without problems. If spores of a parasitic fungus penetrate into a fresh crack, the apple tree becomes ill with cancer. And the wounds do not heal anymore.
The disease spreads similarly to black cancer. Yellow spots appear on the bark. Then, in the focus of the disease, the bark begins to die off and dry out. Over time, it will fall off completely, leaving a trail of nodules and swellings. Spores of the fungus are transferred by the wind during the warm summer period. In winter, the disease lulls.
Root cancer appears due to the efforts of a rod-shaped bacterium that lives in the soil. A large number of fruit plants of 18 different families are affected. Bacteria enter the roots of the tree through wounds and cracks, multiplying there through rapid division. Growths and nodules form on the roots, which, when rotting, release a huge amount of harmful bacteria. They are able to live in the soil for about two more years.
The root collar of a tree is the most dangerous place for root cancer. In this case, the tree is doomed to death. A favorable soil for bacteria is the land, in which seedlings and seedlings are grown in the same place for a long time.
Experienced gardeners know perfectly well what tree diseases look like. They read the necessary books and guidelines for tree care. It is not enough just to plant a tree, you should always be ready to protect it, because plants are living beings. Their death is unacceptable.
An experienced gardener will tell about the cancer that affects the apple tree in the video: