How to treat apple from bark exfoliation
Tree bark diseases pose a great threat to the apple tree. It would seem that in winter the gardener has nothing to fear, because this is a time of respite and rest for the trees. Unfortunately, this is not so - diseases affect plants throughout the year, and in autumn and winter, trees are most vulnerable to damage to bark and wood. This article is devoted to the causes of exfoliation of the bark on the apple tree and methods of treatment and prevention of this unpleasant phenomenon.
Why does the apple-tree bark peel off
The cause of cortical disease is usually the presence of active sources of infection (bacteria and pathogens) on the trunk and branches. This leads to the development of infections during the growing season, including late autumn and the beginning of winter, when the temperature in the street does not drop below zero. The presence of wounds on the shoots formed after pruning, the fall of a large hail, a hurricane wind, or breaks on broken branches under the snow are open gates for infection.Damage to the tree bark can also be caused by feeding birds (woodpeckers, tits) that feed on the larvae of pests living under the bark of an apple tree. The culprits of diseases of the tree bark are fungal pathogens, which also have the ability to infect flowers during the flowering period of the apple tree, and then fall into shoots. Fungal diseases are very dangerous and capable of affecting the fruit crop.
Important! The gardener should not be touched by the businesslike, brightly colored woodpecker that appeared in the garden, his presence means unpleasant news - some of the trees are infected with a bark beetle.
The most dangerous diseases leading to stratification of the cortex are gangrene and black apple cancer.
Causes and symptoms of diseases:
- Gangrene bark - pathogens are conidia Pezicula alba and Pezicula malicorticis. This is a dangerous disease, especially in nurseries and young apple orchards - infected trees can die soon after planting. The bark of infected shoots darkens, dries and wrinkles, after which it often exfoliates from the trunk. Saplings affected by diseases die, and on the thick branches of old trees, longitudinal strips of dying bark form. Conidial spores of gray color are active and capable of infection throughout the warm period, from spring to autumn, penetrate shoots through mechanical damage (after pruning, vaccination, feeding of pests). Autumn infections are one of the most dangerous because they lead to the formation of extensive wounds that spread to most branches or trunk.
- Black cancer, the causative agent of the disease are spores of the fungus Neonectria galligena. Mostly infected branches and young apple shoots. Necrosis occurs on the affected areas, as well as a thickening of the edges of the wound, there are influxes from the cortex. The fungus also develops inside the wood of infected shoots. A brown-red mycelium appears on the dead tissues of the cortex inside the wounds and develops from late autumn to spring. In our climatic conditions, black cancer infection occurs mainly in the fall, most often due to pathogens present on fallen leaves, wounds after cuts, agricultural treatments or frost damage.
Animals and Pests
Young delicate apple barks are enjoyed by rodents such as hares and mouse voles. A special danger for apple trees occurs in the winter. At this time, it is difficult for rodents to get food under the thickness of snow, so they go to orchards in search of food.
Did you know? Some Amazon tribes, still living in a primitive communal system, consider the larva of the local bark beetle a delicacy and very satisfying food.Larvae are obtained from under the bark of dead trees, they are painted white, their thickness reaches 2 cm, and their body length is 4 cm.
The result of the activity of rodents is hanging tatters torn into shreds of the trunk. Through the wounds left from the teeth of mice and hares, the infection subsequently penetrates the wood, and as a result, the tree becomes sick.
Burns and frostbite
Necrosis on the trunk covering is formed in a place that has been frostbite or damaged by sunlight. Typically, trees get sunburns in early spring, from the end of March to the end of April, as a result of which the layer of bark detaches in whole layers. The wood of the apple tree damaged by sunburns acquires a burgundy hue at the site of the lesion. Prevention of sunburn is timely spring whitewash.
In winter, the apple bark can be damaged as a result of exposure to severe frosts. After winter frostbite, deep cracks appear on the trunk. The color of the trunk of a frostbitten branch does not change color. The apple tree can heal wounds received from frost on its own, during the movement of the juice, so gardeners after frostbite do not treat cracked trees with garden varieties or any other healing paste.
Important! Experienced gardeners recommend whitewashing wood in early spring, even before the buds swell. During this period, the sun becomes active, even aggressive.
To reduce the possibility of sunburn on a tree, the gardener exposes the stem and lower part of the skeletal apple branches to whitewash. To protect the tree bark from frostbite and sunburn in the winter, whitewashing is carried out in the fall. For this procedure, choose the time closest to winter, for example, in early November. The timing is determined by the fact that autumn is rich in precipitation, which can partially wash away the whitewash from the apple tree.The whitewashing procedure is repeated in early spring in order to protect the tree from burns during the summer. Whitewashing is applied to the tree trunk, starting from the border with the soil. Also, the lower part of the skeletal branches is treated with whitewash, approximately 50–70 cm from the base. Whitewashing has a liquid consistency, so it is convenient to apply it to the surface of the apple tree with a flat wide paint brush.
How to cook whitewash:
- Mix water and lime per 10 l of water 1 kg of lime. After mixing water and lime, a quenching reaction occurs, which causes whitening of whitened water.
- When the slaking of lime is over, a couple of kilograms of fresh horse manure and 100 g of copper sulfate are added to the mixture.
- The solution is thoroughly mixed a second time until a uniform, thick liquid is obtained and is immediately used for its intended purpose.
Improper tree care
Damage to the tree cover can sometimes cause improper care of the apple tree, for example, exceeding the recommended dose of fertilizers. A large amount of nitrogen in top dressing can cause rapid growth of wood, behind which a slowly growing woody shell will not be in time. The discrepancy in the growth rate contributes to the appearance of breaks in the cortex.
Methods of treating apple from bark exfoliation
Damage to apple trees can be treated in two ways, both medically, using chemicals, and mechanically, using wood cleaning and applying dressings.
Such treatment involves the complete cleaning of the affected areas using a knife or other tool with a sharp cutting edge. Also, disinfecting fluids and mixtures are used in the treatment, which completely isolate the damage from contact with the external environment.
Important! Sometimes gardeners prune diseased branches, removing directly the area of damage.It seems necessary to cut wood that seems healthy because spores of fungal diseases can affect wood at a distance exceeding 25–30 cm
After each use of the cutting tool or before moving on to working with another tree, the knife or secateurs are soaked for 5 minutes in a liquid containing chlorine to disinfect. For these purposes, you can use "White", a tool for bleaching fabrics.The peeled bark of an apple tree.
With the mechanical method of treating the apple tree, all branches on which the symptoms of the disease are visible are ruthlessly removed. Thick branches are cut with a hacksaw with small teeth, and thin shoots are cut with a garden pruner with well-sharpened blades. Sharp secateurs blades are a guarantee that removal will take place with minimal damage to the wood, without creases. The truncation site of the affected branch is determined as follows: it should be 30–40 cm higher from the detected focus of the disease.
If damaged by animals
For extensive and serious damage to the woody shell, a normal garden var is applied. Affected areas of animal wood are cleaned from damaged bark and a bandage is applied over a layer of a garden var.
If, as a result of the disease, a large hollow has formed on the trunk, it is also cleaned of dead wood, and then covered with a mixture of sand and cement. This is done so that precipitation and oxygen, which could cause the onset of decay, do not get into the hollow in the future.
Bark beetles are a very dangerous pest for fruit trees. The dense population of the apple tree by the bark beetle leads to the undoubted death of the plant, it is impossible to cure such a tree. At the first signs of the appearance of a bark beetle in any part of the apple tree, the gardener should remove the infected branch and burn it.Small damages resulting from the harmful activity of insects or birds are cut with a knife to clean wood, and then the cleaned surface is treated with a thick clay solution or any oil-based paint for wooden surfaces. After cleaning the bark, tar or products containing mineral substances should not be used, as they will cause an additional burn of the wood, and, possibly, the wood will dry out.
With temperature differences
Small long cracks in the bark may appear on the apple tree. They arise due to a sharp transition from the thaw to subzero temperatures. Typically, such damage to the gardener can notice with the advent of spring. Cracks lead to peeling and falling of the woody shell. These injuries can also not be ignored, because in the future, spores of fungal diseases may develop in these wounds or they will be occupied by pests.
To help the tree, the gardener should use a knife to clean off the edges of the longitudinal wound, then rub copper sulfate into the damage, and make the treatment of the damage with a thick mixture of clay and mullein or garden varieties. After the treatment, the longitudinal crack is wrapped in polyethylene, which contributes to the rapid healing. After 30 days, the polyethylene is removed and replaced with a natural burlap dressing.
If the bark on the trunk has departed due to fungal diseases, the apple tree must be treated with chemicals such as fungicides. Chemistry is applied not only to the damaged area, but they also process the entire surface of the tree. The treatment is carried out immediately, as the first signs of the disease will be noticed.
For treatment with chemicals, a hot day without precipitation is chosen. If it started to rain a few hours after the treatment, the treatment must be repeated when the raindrops dry on the trees. Chemicals are applied to the branches of an apple tree using a garden sprayer using the spray method.
Important! When starting work with chemicals hazardous to health, the gardener should use all safety precautions: wear clothing that covers his arms and legs completely, a respirator, glasses and a hat.
Against the bark beetle
After the detection of pests, the chemical treatment of the plant is carried out immediately with one of the chemical preparations: Confidor Extra, Calypso, Pirinex, Arrivo. It should be remembered that these drugs are insecticides and are dangerous not only for the bark beetle and its larvae, but also for bees and other beneficial insects.A diseased tree can be treated with an organic preparation, such as Bitoxibacillin, but it should be borne in mind that it has a weak effect on the pest and requires multiple treatments (at least five), with an interval of 7-10 days.
To get rid of diseases, the surface of the tree is treated with chemicals specially designed to fight infections.
Did you know? A small titmouse can, flying in the garden, eat a lot of insects per day, whose weight significantly exceeds its own.
Infectious diseases treatment:
- Bark cancer. It’s difficult to fight this disease on the apple tree. Infection can develop at a distance of up to 30 cm from the site of infection. The main procedure that limits the development of the disease is the cutting of infected shoots and the fight against bark beetles. Wounds after pruning and hail should be carefully coated with garden paste, with a high degree of infection in the garden - sprayed with fungicides. One of the most effective drugs in the fight against fruit tree cancer is the drug Topsin M 500 SC.
- Gangrene bark. Chemical protection against stem gangrene should be applied after heavy and prolonged rains, from the stage of the appearance of buds to harvesting fruits. Mechanical damage or wounds after trimming should be treated with a paste containing the substance thiophanate, for example “Funaben Plus 03 PA”.
Preventive protection of apple trees from bark diseases should be carried out regularly throughout the year. The time when the largest number of infections develop that contribute to stratification of the cortex is a warm period with high humidity, which contributes to the development of pathogens. Immediately after harvesting, it is recommended that apple trees be treated with Topsin M 500 SC (1.5 l / ha) or Viflo Chitosol Silver (5-7 l / ha).
How to prevent illness:
- Prevention in the fight against gangrene bark basically consists in cutting infected shoots, the cut is carried out below the site of infection. In order to minimize the risk of infection, it is recommended to use (in early spring, after pruning) preparations from the benzimidazole group, such as Topsin M 500 SC.
- Black Cancer Prevention: planting proven, high-quality planting material from nurseries with a good reputation, as young trees often become infected in breeders with bark infections.
- To protect the apple tree from getting frost bark, gardeners additionally insulate the trunk and skeletal branches of the plant. For insulation use burlap or natural cotton fabrics, wrapping them in several layers around the trunk and branches. Fabrics are fastened around the tree with soft wire or twine. In severe frosts, such warming is not very effective, but it will not be out of place during the difference in daily temperatures.