Types of apple burns and how to treat them

Types of apple burns and how to treat them

Many gardeners try to grow apple trees. But sometimes they have problems. And one of the frequent difficulties is the appearance of burns.

Causes

If the apple tree is suddenly covered with burns, the reasons can be very diverse, the sun is far from always to blame. Often, pathological bacteria are the real source of the problem. They mainly operate in the southern regions of the country. Separate messages about their activity come from the Voronezh region, from the vicinity of Tambov and from the south of the Far East. If the pathogen is the microorganism Erwinia amylovora, it is most active when the air warms up to 25 degrees.

Another favorable condition for it is relative humidity from 80 to 90%. In order for the diagnosis to be accurate, a special study will be required. Bacterial burns of apple trees are often provoked by the microbe Pseudomonas syringae. The term of the highest activity of both microorganisms coincides, and both of them are forced to carry out phytosanitary quarantine measures. Therefore, at the slightest suspicion, you need to contact specialized organizations; another ailment can hit the apple tree after spraying in violation of the technology of work.

Varieties and symptoms

Monilial burn of apple trees is one of the main dangers for this crop. A similar lesion manifests itself in the spring, when flowers die and flower stalks disappear, when branches suffer and dry out.In autumn, the disease passes into the stage of fruit rot. It lowers the yield and reduces the quality of the remaining fruits.

A monilial burn that covered large branches and a trunk looks like this:

  • the bark is cracked and swollen;
  • she seemed to have moved away from the wood;
  • cracks appeared along the trunk;
  • these cracks end in ulcers.

Young (developing the first year) shoots are covered with scaly skin. The bark in different places has an unequal geometry. But everywhere its surface is smooth, light brown. Manifestations resemble a normal sunburn. When winter comes, the trees are covered with dried leaves; still weak ovaries and remaining flowers are visible everywhere.

Fruiting branches with moniliosis are subjected to algae aggression. Their colonies are clearly visible. On the shoots of the first year of development, you can find villi that contain a growing mycelium. The surface of the bark may be covered with white or cream-colored pustules, including fungal spores.

When an apple tree is affected by moniliosis, its fruit buds are dull in color and have excessive pubescence. They are not completely covered with scales. As soon as the flower opens, it becomes clear: the stamens and pistil have acquired the same brown color. The plant does not produce nectar, and therefore pollinators fly around it indifferently. Changes also affect the leaves: reddish dots are visible on them, and sometimes the entire surface turns red.

All these signs are important - they allow you to accurately recognize the nature of the disease.

The microorganism that provokes a bacterial burn spends the winter only in the affected trees. It is the ulcers that survived the cold season that turn out to be the main "culprit" of its spread.Even when the bark is completely intact, microbes can enter through the flowers or through the stomata. If you start the development of the disease, the tree can be completely affected. Sometimes this leads to its death.

An early symptom is the death of individual groups of flowers. They rapidly darken, sometimes completely blacken. The opening of the kidneys is impossible, but, having changed radically in color and dried up, they will remain in place. Then the branches will wither and die, after which the turn of shoots will come. At first, these parts look like they are oversaturated with moisture.

Soon, the exudate (liquid of plant tissues) will come out, its drops will be clearly visible on the bark. Young parts of the tree wither, while their tips are bent into hooks. Even dying leaves remain in their place. At the same time, the further spread of microbes continues. For their movement to new areas, they use the arterial vessels in the central part, as well as the veins of the leaves and the peduncle.

If a pathological microbe manages to get into the newly formed fruits, they will quickly darken and dry out. But, like everything else, they will retain their places. Ripe fruits that have become ill with a burn have small dead spots of almost black color. The presence of exudate is not a strictly mandatory phenomenon. Possible infection of immature fruits occurs through pores or various deformations.

If the apples are infected from mid-July to the end of August, greenish spots of a watery texture will initially appear on them. Soon they will become an intermediate shade between red and brown. At the same time, exudate flows from the stomata, outwardly resembling milk. First of all, the branches and trunk are affected in the upper parts of the shoot. The movement of the infection further occurs along the parenchyma of the cortex.

Patients with a bacterial burn of the cortex have spots of a dark green color. Many of these spots have a watery texture. The border of the affected areas and healthy plant tissue is barely perceptible in appearance. There is a detachment of the epidermis with the appearance of peculiar "bubbles". Cracking of the bark at a later stage makes the boundary of the lesions more clear around the entire perimeter.

But this is no reason for reassurance. If wedge-shaped ulcers are seen, then one can fear that they will destroy the entire tree. On warm days, drops of milky liquid ooze from diseased areas of the apple tree. Gradually, the tissues of the tree become drier, a specific microflora develops in them. This is expressed in the fact that the exudate turns brown.

How to treat?

Modern methods of treatment of monilial burns are quite effective. Before buds open, any previously affected tree organs must be cut out. Destroy and dry flower stalks, and individual thin branches. This technique allows you to reduce the aggressiveness of the infection and make therapeutic measures more effective.

At the same time, an apple tree is sprayed using preparations containing copper:

  • chloroxide;
  • Bordeaux composition;
  • "Abigu Peak".

As soon as the buds open (but even before flowering begins), diseased plants are treated with "Fundazol" or "Horus". After them, the treatment with the already named drugs is repeated. Counteraction to a bacterial burn, which has covered only a few branches, should be carried out with the help of Bordeaux liquid.

It is used five times during flowering:

  • when the flowers are closed;
  • after opening 1/5 of the flowers;
  • when opening 75% of flowers;
  • when petals fall out;
  • once flowering is complete.

In autumn, when apple trees go into a dormant state, single branches are cut.For young shoots, the cutting radius is 200-250 mm, for old shoots - 100-150 mm. To exclude the resumption of infection, it is required to uproot wild fruit and berry plants in the garden. In the future, it is recommended to select the most resistant varieties to infection. It is also important to normalize the acidity of the earth, to adjust the balance of trace elements.

Important: the treatment of any ailments of apple trees with copper sulfate should be done with great care. Often it is this that provokes the occurrence of new burns. The probability of such a development of events is especially high in case of violation of the terms of processing.

Of the special plant antibiotics, Fitolavin and Gamair are best suited to combat bacterial burns. The second is safer, but less efficient.

"Gamair" is optimal for preventive spraying. They are carried out from the first spring days until the end of the growing season. If the disease still struck the apple tree, you should proceed to the use of more effective means. "Fitolavin" in the form of a solution is used when the buds separate, when flowering occurs and the ovaries are formed.

All drugs can not be used during the flight of bees; It is also worth abandoning the use of "human" drugs.

How to prevent problems?

For gardeners, it is not difficult to prevent moniliosis. As soon as spring comes, it is required to examine the plants. Dried branches are cut from apple trees, and thickened crowns are cut. If there are peelings of the bark somewhere, these places should be cleaned. The same is done with lichen foci. Important: all cuts and cuts must be covered with paint that is safe for trees or treated with garden pitch.

The trunk is whitened, as are large branches. Prevention of moniliosis includes the use of fertilizers based on phosphorus and potassium. Be sure to clean up debris and vegetation residues left over from last year. The soil in the trunk circle and some distance beyond it needs to be dug up. Young trees are watered 2 or 3 times per season with root development stimulants.

It is important to water the apple trees and ensure the continuous moistening of the earth. An additional support measure is a special treatment that deters pest invasions. It is useful to fight certain diseases that increase the risk of contracting moniliosis. When using synthetic products, the manufacturer's recommendations must be strictly followed. Do not rely solely on "artisanal" means - many of them are ineffective.

If infection of new trees with fire blight cannot be avoided, the rate at which the infection travels can be reduced. To do this, it is necessary to strictly observe phytosanitary restrictions in places that have not yet been infected. This requirement is important for valuable plants.

It is categorically unacceptable to import planting material from foci of bacterial infection. In case of severe damage, the trees are removed from the ground and burned completely, without using the wood for any other purpose.

Methods for the prevention and treatment of monolial burns on fruit trees, see below.

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The information is provided for reference purposes. Do not self-medicate. For health issues, always consult a specialist.

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