Diseases of apple trees

Diseases of apple trees, both trees and seedlings, can not only deprive them of their harvest, but also cause death. Experienced gardeners recommend in advance to attend to the study of the list of diseases dangerous to the apple tree, as well as measures for their treatment and prevention.

In this article, we list the main types of apple diseases of infectious, physical and mechanical origin. It should be borne in mind that only carefully planned disease control measures are effective, taking into account not only the positive, but also the negative consequences of using a particular agent.

Many chemicals have a high level of toxicity and, despite their effectiveness in treating apple diseases, can harm fruits and human health. It is also necessary to observe all the precautions that are included in the instructions for use of the medicinal product.

The study of this article will help determine the type of disease of apple trees and choose the measures necessary to cure it that will save the harvest.

Diseases of apple trees: lichens

apple diseases

Such diseases of apple trees as lichens affect all varieties of fruit and berry crops. A favorable factor for their development is the increased level of moisture resulting from too close proximity of trees and shrubs.

In such conditions, the lighting and ventilation regime suffers, therefore a damp environment is formed, which contributes to the spread of various types of moss and lichens that cause tree diseases. These harmful organisms can quickly migrate to neighboring plants, as evidenced by the sparse crown, weak, slowly growing shoots.

The lichen-covered bark of the apple tree stores moisture, which contributes to the formation of cracks in frosty winters. Subsequently, harmful insects hibernate under the exfoliated bark. The very appearance of lichen indicates a reduced immunity of the plant.

How to deal with the disease: it is necessary to regularly remove lichen thallus from the trunks and branches, and in the fall, spray the trees with a solution of ferrous sulfate, also called ferrous sulfate, at the rate of 300 g of composition per 10 liters of water.

Fungal lesions of the trunk and bark - common diseases of apple trees, description

apple diseases

The trunk and bark of an apple tree are often affected by fungal infections, which are referred to as cancers. Consider several types of cancer affecting apple trees:

1. Common apple crayfish (European) is caused by the activity of a fungus called Neonectria galligena and appears as long brown spots. Gradually, their surface dries up and becomes covered with cracks, through which ulcers surrounded by callus tissue appear.

Over the course of several years, they increase in size and become deeper, the gradual dying off of wood leads to the death of the tree. Young apple trees die within 2-3 years. The spread of cancer through the tree is carried out by spores that mature in whitish (and then dark) seals around the ulcers.

Thus, not only the trunk is affected, but also branches, foliage, fruits. Open sores are most often formed on the trunk of a tree, while closed cancers infect the branches, creating solid, dense patches.After a while, they crack.

The leaves of the apple tree are also covered with brown spots, then they gradually dry out and fall off. In a similar way, fruits are affected, which begin to rot quickly.

The fungal infection continues to live and develop in the wood and other parts of the plant. A wide range of diseases with common cancer leads to massive lesions of tree crops, provided they are crowded in a limited area. The risk factor is the weakened state of the seedling and the presence of traces of mechanical damage and frost breaks.

How to deal with the disease: first of all, you need to take care of the quality of the planting material, you should choose seedlings without damaging the shoots. It is also imperative to follow all the recommendations for growing crops, regularly cutting and destroying dry branches and foliage.

Single ulcers that appear in the places of branching of skeletal branches can be disinfected with a solution of ferrous sulfate (1%), and then covered with a layer of natural oil paint. It is also shown annually in the spring, before the leaves appear, to treat trees with Bordeaux liquid or similar preparations like "Abiga-Pica", "HOM".

2. Black cancer on apple trees is caused by the appearance of the fungus Sphaeropsis malorum Berck and most often affects the skeletal branches in the places of their branching. This is evidenced by indentations of a reddish-brown shade with a tendency to darken.

The surface of the bark is covered with pycnidia containing spores. The surface of the bark turns black, becomes covered with bumps, cracks, and as a result, whole layers dry out and flake off in large pieces. Cancer-infected leaves and fruits also become covered with dark putrefactive spots. In case of a disease of the standard part of a tree, cancer destroys it within 2 years.

This disease also quickly spreads in close plantings of fruit and berry crops, roaming from apple trees to pear trees. This leads to the necessary measures for cutting diseased branches of the skeletal type, from which the crowns of trees lose their decorative qualities. Infected plant parts are carriers of infection.

How to deal with the disease: similar to the case of common apple cancer, the health of the seedlings and adherence to all agrotechnical recommendations play a major role. As a preventive measure, irrigation with Bordeaux liquid (1%) and its analogues is carried out annually.

The affected branches are cleaned, disinfected with an already known solution of copper sulfate, followed by applying oil paint. Dried branches are subject to cutting and subsequent destruction.

Drying of the bark

Often, the deformation and drying of the bark of apple trees is of an infectious origin and is called cytosporosis. Its pathogens on apple trees are the fungus Cytospora (varieties schulzeri and carphosperma), on pear and apple trees, Cytospora microspora Roberh.

In the course of the development of the disease, the standard parts, the surface of the bark and branches are covered with convex brown seals, which gradually open, damaging the integrity of the bark. It begins to become covered with tubercles, and then crumbles. The disease spreads to the wood, the branches begin to dry out.

Risk factors are the low quality of seedlings, the presence of mechanical injuries as a result of frequent pruning of branches, sun and frost injuries. Infected tissues of bark, wood, foliage retain foci of the disease.

How to deal with the disease: Prevention and treatment measures are the same as in the case of infection with black cancer.

Diseases of apple trees in the spring

The causative agents of the so-called spring diseases develop in the bark of trees throughout the winter, and with the onset of warm weather they manifest themselves most actively. These include the fungus Tubercularia vulgaris Tode, which causes necrosis of the bark of shrubs and deciduous trees.

Affected shoots and foliage turn brown and dry. The bark becomes covered with reddish seals, which dry out over time and acquire a dark color.Gradually, the affected areas of the bark and fibrous tissues die off, pathogens remain in them.

Often the source of mass disease of apple trees is red currant, whose bushes are often affected by this fungus.

How to deal with the disease: Prevention and treatment are the same as those against common cancer.

In the spring, another mushroom called the comb, Schyzophyllum commune Fr. It develops on trees weakened by frostbite, causing trunk rot. Fruit and berry trees and shrubs fall under its action.

Symptoms of infection are grayish-white fruiting bodies in the form of numerous thin caps that have spread along the trunk and branches of the tree. The disease spreads very quickly and causes the tree to dry out. The infection continues to live inside the fruit bodies and woody tissue.

How to deal with the disease: as in the case of cancer, destruction of dry branches, cleaning of unhealthy parts of the plant, disinfection of wounds and preventive irrigation with the help of already familiar preparations is shown.

Root rot and scab

Damage to the trunk by root rot or scab can destroy the apple tree. The source of root rot is the fungus Armillaria mellea (Vahl.) P. Kumm., Also called honey agaric. It grows on tree roots and tree stumps, spreading under the bark through cord-like plexuses of mushroom filaments called rhizomorphs.

Fruiting bodies have the appearance of a mushroom with a yellowish-brown cap and an annular film under it. This peripheral rot starts at the roots, but eventually destroys the trunk of the tree, covering it with numerous brown spots. The fungus persists not only in the infected parts of the plant, but also in the soil, infecting surrounding trees and shrubs.

How to deal with the disease: with the onset of the disease, it is necessary to treat the soil around the tree with compounds containing copper. In large gardens, it is recommended to treat the roots with a mixture of insecticides and fungicides. The so-called tank mixture includes 0.2% of foundation and 0.4% of "HOM".

Therapeutic and preventive procedures are identical to those given above. Scab disease (fungus Venturia inaegualis Wint.) Is no less dangerous for apple trees. It appears in the form of dark green spots covering the leaves, after which they turn yellow and fall off. The size of the spots varies depending on the season: in spring and early summer they are large, then they become smaller.

The fruits also turn brown and become inedible. Scab reduces productivity and deprives apple trees of their decorative qualities, lowers their immunity and resistance to cold. A suitable environment for the fungus is high humidity in the spring and summer. Scab is dangerous only for the apple tree, remaining in its infected tissues, fallen leaves and dry branches.

How to deal with the disease: The foliage that has fallen from a diseased tree must be removed from the garden and destroyed. Shown are spraying of apple trees at the stage before and after flowering. For this, Bordeaux mixture and its analogues, "Skor", "Raek", are used.

Powdery mildew

Infection with powdery mildew threatens curling and drying of foliage, as well as slowing down the growth of shoots. Its causative agent is the fungus Podosphaera leucotricha Salm., Which manifests itself as a milky white cover on the surface of leaves and flower petals, which infects the rest of the tree and neighboring plantings.

Gradually, the leaves curl and die off, the shoots stop growing and change shape. The buds affected by powdery mildew do not bear fruit, and the apples are covered with a hard, reticulated, rusty bloom.

Favorable conditions for the development of the disease are plantings thickening, lack of light and ventilation. Powdery mildew disease is dangerous not for apple trees alone, but for pear plantings, albeit to a lesser extent. Fungal spores persist in leaves, buds and bark.

How to deal with the disease: as in the case of scab disease, it is necessary to promptly remove infected plant residues from the site, as well as take preventive treatment measures.

Leaf lesions

The appearance of uncharacteristic spots on the foliage of apple trees indicates the presence of an infectious infection, or an injury of mechanical or thermal genesis. One of the causative agents of leaf infection is a fungus (Gymnosporangium tremelloides Hartig).

Less commonly, branches and apples are infected. The surface of the leaves is covered with reddish pads with clusters of black dots in the middle, on their backs spore-containing cones are formed, first orange, then brown.

Infection of the apple tree occurs as a result of the proximity to the carrier of the fungus - the Cossack juniper. The spores overwintering in its bark migrate to the apple tree, infecting it.

How to deal with the disease: in the period before and after flowering, trees are treated with already familiar copper-containing products.

Leaves are often affected by brown spot caused by fungi Phyllosticta mali Prill, et Del. and Ph. briardi Sacc. In the first case, the fungus covers the leaves with yellow spots with a dark border, which have an angular shape.

The second type of mushroom gives spots of light color without a border - round and angular. Fruit bodies are formed in the dying tissue, yellowed foliage falls off, in which the spores of the fungus persist.

How to deal with the disease: preventive and therapeutic measures are identical to those given above. The fungus Ascochyta piricola Sacc., Which causes the ascochytic spot, is dangerous for both the apple tree and the pear.

Infection is indicated by gray spots, which eventually merge, the process of formation of bodies carrying spores is underway. Yellowed dry foliage falls off, retaining spores in its tissue.

How to deal with the disease: The disease is treated in the same way as brown spot.

Another reason for the appearance of spots on the leaves can be chlorosis, associated with a decrease in photosynthesis due to a lack of nutrients or mechanical damage to the plant.

How to deal with the disease: it is necessary to establish the causes of the development of chlorosis in time. Bordeaux mixture and its analogues are used for spraying, copper sulfate solution and oil-based paint - for disinfection and healing of wounds.

Diseases of apple trees and their seedlings

Young apple trees at 1-2 years of age, as well as young shoots of adult trees, often become victims of moniliosis caused by the fungi Monilia cinerea Bon. f. mali Worm, and M. fructigena Pers. In the first case, the plants get burned, causing drying out of all parts of the tree. In the second case, the process of fruit rotting begins, especially in those places where the moth has visited.

The decaying tissue gradually becomes covered with spore-containing, rounded gray pads. Spreading together through the air, moisture and insects, the spores infect nearby apples, causing them to darken and dry out. If you leave them on the branches, the focus of infection will remain and will serve as a source of infection.

How to deal with the disease: it is necessary to promptly remove the affected apples, carrion, dry branches. Shown is the traditional double spraying with Bordeaux liquid or its substitutes. In especially difficult situations, after 10-12 days, it is possible to carry out the third procedure.

Rolling the leaves

Ailments of apple trees, manifested in the twisting of foliage, threaten other crops as well. It is necessary to identify them as early as possible in order to avoid mass infection. One of the pathogens is the mushroom Pestalotia malorum Elenk. et OM.

Their defeat leads to the appearance of rounded gray-brown spots, which gradually merge, then pads bearing spores appear. The foliage takes on a brown color and dries up, continuing to remain a source of infection.

How to deal with the disease: as in the case of other leaf diseases, it is necessary to remove fallen leaves from the site and carry out preventive spraying with already known drugs.

Tobacco necrosis caused by the Tobacco necrosis virus (TNV) is systemic in nature and is characterized by a gradual death of leaves, beginning with the stage of spotting. Other manifestations of the virus are deformed leaves, oppression of buds, slow growth of shoots.

Numerous representatives of fruit and berry, vegetable, flower, industrial crops are exposed to it. The virus spreads through plant sap and zoospores.

How to deal with the disease: the health of the seedlings plays an important role, it is equally important to follow agrotechnical recommendations. With the appearance of the first symptoms of the virus, it is necessary to remove the infected parts of the plant with their subsequent destruction.

All garden tools used to trim diseased tree parts should be thoroughly disinfected with solutions containing alcohol or potassium permanganate.

Diseases of young apple trees

Young apple trees are affected by a variety of diseases, the greatest danger of which is damage to the bark caused by exposure to low temperatures. If an adult specimen of an apple tree has a chance of recovery, then young plants die within a few days.

One of these dangerous diseases is cancer that affects the bark of the apple tree, caused by the bacterium Pseudomonas syringae van Hall. This disease leads to the formation of burn-like spots all over the bark and leaves. With a burn, they are related by the formation of blisters and crimson spots.

The developing process of decay is accompanied by the appearance of a pungent odor characteristic of fermentation. Gradually, the tree dies. The chronic form of cancer is characterized by the appearance of ulcers on the surface of the trunk and branches, which enlarge, secrete juice and mucus, and then dry out.

The spread of bacteria is carried out by wind, insects, gardening tools and infected seedlings.

How to deal with the disease: The measures to deal with the disease are the same as for other cancers.

Fruit affections

In the process of bud formation, flower ovaries on apple trees can be affected by phytoplasm (Apple proliferation, Apple witch's broom). A characteristic manifestation of the disease is the formation of the so-called witch's brooms.

The causative agent is activated in the second half of summer: the shoots of apple trees are abundantly overgrown with thin long and very frequent shoots. Their small leaves have an atypical jagged outline.

Affected apple trees bear small flattened fruits that have no taste. Flowering in such trees is late, and the inflorescences have an unhealthy green tint and ugly shape, the foliage turns yellow and falls off early.

The stem part of the apple tree is often covered with root shoots. A diseased seedling can be identified by its small growth and increased bushiness. In addition to the apple tree, witches' brooms successfully develop on quince, being transmitted through planting material, grafts, seeds and remaining in the shoots of a diseased plant.

How to deal with the disease: you can prevent infection by adopting all the recommendations regarding the choice of seedlings, disinfection treatment of garden tools, prevention of the disease.

Diseases of apple trees: description of non-infectious lesions and their treatment

Non-infectious diseases of apple trees include hardening and darkening of the surface of the apple skin, called corking. The cause of the disease is the spring freezing of the shoots, which harms the flower ovaries and half-opened buds - they turn brown and begin to fall off. The foliage dries up, and the apples become deformed and corky.

How to deal with the disease: It is not difficult to protect the garden from the frost that occurs in the spring by building a fire that creates a curtain of smoke.Spunbond and similar materials will protect bushes and very young and still weak trees.

A small amount of snow in winter and frequent temperature drops have an adverse effect on apple trees. Large daily jumps from thaw to frost lead to alternate thawing and freezing of the bark and its cracking.

The bark of the affected trees is covered with light spots (mainly from the south and southwest), the growth of branches, the formation of ovaries and flowers slows down. In August, the bark can crack and begin to lag behind the woody tissue, which in turn begins to die off throughout the trunk and on the branches.

All this weakens the trees, the risk of infection by infectious diseases increases. In case of freezing of the root system, the tree may dry out at the beginning of the summer period. Mechanical damage to apple trees can also lead to their death.

Branches of apple trees can break under the weight of sleet in winter or a bountiful harvest in summer. Strong winds and careless transportation also often damage them. To protect young apple trees, it is recommended to tie them up with a rope or twine, shake off the adhering snow in winter.

Newly placed seedlings need to be tied to a support to prevent damage to the trunk. Any wounds at the site of fractures must be disinfected with copper sulfate and covered with a layer of linseed oil paint. Cuts and breaks are the starting point for wood cracking, which ultimately leads to the death of the apple tree.

Diseases of apple trees pictures