Content
- 1 The causative agent and reasons for the appearance of black cancer on an apple tree
- 2 What does black cancer look like on an apple tree?
- 3 What can be confused with
- 4 Is the disease dangerous for humans?
- 5 How and with what to treat black cancer on an apple tree
- 6 Preventive measures
- 7 Varieties of apple trees resistant to black cancer
- 8 Conclusion
Black cancer on an apple tree is one of the diseases that requires the close attention of any gardener. The success of tree treatment will depend on the timeliness of measures taken.
The causative agent and reasons for the appearance of black cancer on an apple tree
The synonymous name for the disease is fireweed. Its causative agent is the fungus Botryosphaeriaceae. It is this that attacks fruit trees under certain conditions. Where the fungus accumulates, the color of the wood changes: it becomes like charred.
And although black cancer most often affects the apple tree, other trees can also be affected. The biggest danger of the disease is the speed of its spread. Spores can be spread throughout the garden area by wind and precipitation.
Trees with a weakened immune system, as well as old apple trees, are at risk of being affected by black cancer.
The mechanism of spore penetration is simple: they enter through the damaged bark and then remain there until favorable conditions occur. Most often, the first signs begin to appear with the onset of warm weather.
What does black cancer look like on an apple tree?
It should be borne in mind that in the early stages it is almost impossible to recognize the fungus. To minimize risks, you need to regularly pay attention to the apple tree, inspecting it for damage.
Before starting treatment for black cancer, you need to determine the disease. You can use photos, videos, and the experience of gardeners for this.
If the fungus penetrates the tree through the bark, the crop may die within three years. The duration of the incubation period is 2-3 weeks. Upon examination, you can notice damage on the bark, which is surrounded by purple-brown spots; they gradually grow and change color to black.
Neglected black cancer on an apple tree means deep dark dents on the trunk, peeling of the bark
You can also suspect a disease when examining flowers: their color becomes brown, the petals become deformed and dry out. A characteristic sign is the blackening of the pistils and stamens.
Black cancer affects fruits when they are ripe. The incubation period lasts 6-9 days, after which dark spots appear on the skin of the fruit, prone to growth. The apples shrink and gradually become mummified.
As the black cancer progresses, the leaves become covered with red-brown specks, which gradually grow and change their color to gray. Without treatment, the leaves dry out and die. The completely green mass falls off within two months if no measures are taken.
What can be confused with
It should be borne in mind that the apple tree can not only not be saved from black cancer, but also be completely destroyed if the disease is incorrectly identified.
Important differences from similar infections:
- Cystoporosis: gray spots on the bark that do not turn black over time.
Externally, the trunk with cytosporosis appears worn out
- Common cancer.
With ordinary cancer, dark red growths appear on the surface
- Moniliosis: the color of the fruit becomes black with a bluish tint.
Moniliosis weakens the immune system, so the apple tree is often affected by several infections at once
Is the disease dangerous for humans?
Touching the affected tree is not harmful to humans. But it should be borne in mind that eating infected fruits is prohibited.
How and with what to treat black cancer on an apple tree
If the fungus has infected the trunk or skeletal branches, and the disease has developed to extreme stages, then such a tree cannot be saved. It should be uprooted and burned. In the early stages, the apple tree can be saved by using several methods.
Work algorithm:
- Cleaning the bark from signs of cancer.
- Collection and destruction of affected foliage and fruits.
- Disinfection of a stripped barrel.
- Preventing the spread of disease.
Fungicides for black apple cancer
Without chemicals, treatment of this disease is impossible. The use of fungicides is one of the effective ways to destroy black cancer in apple trees and prevent an epidemic.
The entire crown of the tree must be treated to eliminate all fungal spores. You should not dig up the soil around the trunk deeply, so as not to damage the roots and provide an opportunity for infection to penetrate into the trunk. It is enough to loosen the soil and spray it with fungicide.
Effective remedies for black cancer - Bordeaux mixture, Fitosporin, Vitaros, Horus
Antibiotics for black apple cancer
The use of this group of drugs is widespread in Europe. Most often they are used for bacterial infections, but they are also effective for fungal infections.
The main agents are streptomycin and tetracycline. To cure an apple tree from black cancer, it is enough to use any form of the drug in the spring: powder, solution or capsules.
One of the options for eradicating the disease is to spray the trees with a solution of streptomycin. To do this, you need to combine 5 liters of water and 1 g of the substance. The second treatment is required after 15-20 days. If necessary, the treatment can be repeated several times.
According to European scientists, the toxic effect of antibiotics is lower than that of fungicides
Injections into the trunk
During the growing season, it is possible to use stem vaccinations with streptomycin. There is a certain algorithm of actions for this procedure:
- On the bark where there are no cracks, you need to drill holes 2 cm deep. They should be located at a height of at least 1 m from the ground.
- Pour 4% streptomycin solution into the hole and then seal it with a stopper.
The essence of the procedure is the introduction of the drug into the trunk of the plant. It can penetrate 2 m up and 1 m down. Injections should be performed up to five times, maintaining an interval of seven days.
The medicine must be administered using a special device
Folk remedies
Opponents of chemicals are looking for ways to destroy black cancer on apple trees using improvised methods. Step-by-step treatment consists of regular use of folk remedies. The effectiveness of the procedure depends on the degree of progress of the disease.
Antiseptics can replace products such as laundry soap, fresh sorrel, and washing powder. You need to dilute them with water and then use them to clean the trunk of rot. You can also wash off fungal spores with a strong solution of manganese.
A common remedy for black cancer on an apple tree is clay mash. To prepare it, you need to pour the mixture 2 cm above the layer, and then leave it to steep for 2-3 hours. Periodically you need to stir the mash to get a uniform consistency.
You need to add fresh mullein to a bucket of clay in a 1:1 ratio. The result should be a product similar in thickness to sour cream.
You need to treat all the cuts with the finished mash, wrap the wound with a cloth or bandage, and then soak it in the medicine again. Throughout the season, the applied bandage must be moistened with water.
An alternative to cloth bandages is a garden bandage.
Instead of clay mash, you can prepare nigrolic putty. To do this you need to mix the following ingredients:
- 140 g nigrol;
- 40 g wax;
- 60 g of ash.
The resulting product must be applied to a trunk cleared of cancer. Periodically, the ointment must be reapplied until a new bark forms.
Agrotechnical methods
To save an apple tree from black cancer, you should follow certain rules:
- pruning must be timely and competent;
- treat all wounds and cracks with garden varnish;
- if the plantings are thickened, they need to be thinned out;
- balanced tree feeding.
You can only plant healthy and strong seedlings with a good root system purchased from a trusted supplier
Preventive measures
You can prevent the appearance of black cancer on an apple tree using the following actions:
- When planting apple trees, you must maintain a distance to prevent the fungus from spreading to other crops.
- Proper preparation of a tree for winter: removing debris, whitewashing the trunk.
- Organization of drainage systems to prevent stagnation of moisture in the soil.
- Only those varieties that are adapted to the local climate should be planted on the site. If you grow a tree in the wrong region, it will be weakened, as it will direct all its forces to fight the surrounding conditions.
Varieties of apple trees resistant to black cancer
Not only compliance with agricultural practices, but also the choice of a suitable seedling is the prevention of black cancer. There are no varieties that are absolutely resistant to the disease, but there are species whose immune systems are quite strong:
- Among the summer ones are Alva and Papirovka;
- Autumn ones are Fridorm or Borovinka;
- Winter ones are Jonathan, Haralson; Bolotovskoe.
The varieties that may suffer most from black cancer are: Scarlet Anise, Memory Kovalenko, Champion, Vanda, Bananovoye, Antonovka
It should be borne in mind that even if the variety has suitable characteristics, poor care and planting will be predisposing factors to the development of the disease. Young seedlings can also be affected, although most often signs of infection can be seen on old trees.
Conclusion
Black canker on an apple tree is a serious disease that cannot be cured in advanced stages. The most effective way to save a tree from disease is to follow the rules of agricultural technology and grow fungus-resistant varieties.In the early stages of black cancer, it is recommended to use several treatment methods at once.
