The range of growth of mountain ash is very wide, it can be seen throughout the European plain, in Primorye, in the Far East, in Siberia. Rowan, even, is one of the plants that make up the upper limit of the woody vegetation of the mountains, so it can often be found in the mountainous regions of the Caucasus, Kyrgyzstan, Kazakhstan, and the Urals. Under natural conditions, the tree grows near roads, in forest glades and in undergrowth, near water bodies. Rowan is actively used in the creation of alleys, landscaping of parks and squares.
Literally, the Latin name of mountain ash is Sorbus aucuparia, which translates as “attracting birds”. However, mountain ash attracts not only birds, but also pathogenic microorganisms and insect pests.
What rowan is sick with.
Rowan, whether it is an adult tree or a young plant, is equally susceptible to diseases. The overwhelming majority of diseases are caused by pathogenic microorganisms of fungal origin. What could be the reason for the appearance and spread of these infections?
As you know, high humidity and certain temperatures are a favorable environment for the development of fungal organisms and pathogens, in this case, are no exception. Therefore, the main reason for their appearance is the increased level of humidity, accompanied by warm spring-summer weather.
If the spring turned out to be warm, then signs of the presence of diseases can be seen already in May-June, and, if the spring weather did not indulge in warmth, then they will appear not earlier than mid-summer.
Depending on the causative agent of the infection, traces of its presence may appear on the leaves, trunk and branches of the tree. So, on the leaves, various spots will be visible, covering part of the leaf plate or its entire surface. Affected foliage is usually deformed. It is twisted, dry and easily falls off in very weak gusts of wind. With the active spread of infection, this phenomenon will soon become widespread. In addition to the fact that the mountain ash will quickly lose its decorative effect, the infection will weaken the tree, which, in turn, will affect its frost resistance.
This is a disease caused by ascomycete fungi. The number of their genera is enormous - over 6,000, and the number of species is ten times greater.
The disease affects the leaves and branches of the tree. Dark, brown-black spots appear on the leaves, which, over time, merge, covering the entire leaf plate. Dents form on the branches, disrupting the flow of nutrients in the plant.
If the disease is started, the anthracnose will spread so much that the entire above-ground part of the tree will simply die off. The leaves, trunk and branches of a tree will dry out under the influence of pathogenic microorganisms. In hot and dry weather, the sections of the trunk affected by the fungus will crack, and in wet and rainy weather they will rot. To prevent such a tree from becoming a breeding ground for infection for neighboring plants, it is better to destroy it. If the disease was detected at its initial stage, first of all, it is necessary to cut off all the affected areas and carry out treatment with fungicides, which include "Abiga-Peak", "Oxycom", copper sulfate.The substances that make up the preparations are introduced into plant tissues, reducing the aggressive effect of the pathogen in already affected areas, and also suppress the activity of the microorganisms themselves. In the future, such treatments are repeated once every one and a half, two weeks.
The causative agent of the infection lives in fallen leaves, where there is always a fairly humid environment and on plant debris in the soil.
In addition to high humidity, its spread is facilitated by the increased acidity of the soil, as well as the lack of phosphorus and potassium.
Spotting (White, Brown, Gray)
Septoria, the name of the disease is consonant with its causative agent - Septoria mushrooms. And its other name - White Spot, already speaks of the results of the pathogen's impact on the plant.
If the rowan foliage noticeably loses its decorative effect, and the spots that appear become more and more noticeable, spreading over the entire leaf area, then the tree is most likely affected by White Spot. The spots characteristic of Septoria have a well-defined dark border and a light center. Little by little, fungal spores will begin to develop in the affected areas. A tree weakened by a disease is no longer able to withstand other diseases, infections and pests.
To get rid of White Spot, branches and leaves with traces of the disease are removed and burned. The tree is sprayed with fungicide solutions. Such drugs as "Skor", "Ordan" or "Profit Gold" have shown high efficiency in the fight against this disease. The latter, by the way, continues to operate even in rainy weather.
Irregular reddish-brown spots on leaves with clusters of black spores in the center are characteristic features of Brown Spot. The disease often appears in the second half of summer.
Black spores, or, as they are also called pycnidia, are not recommended to be touched, since, from touch, they will immediately scatter and settle on other plants. If they are found, you should immediately start treating the tree with chemical fungicides, such as Ridomil Gold, Ridomil or Horus. Brown spot affects absolutely all types of mountain ash.
Along with Brown Spot, in the same period - the second half of summer, Gray Spot may appear. Gray spot differs from the previous disease in that it affects both sides of the leaf and, if the disease is started, the leaf looks like one continuous spot interspersed with black spores. In this case, chemical fungicides are indispensable. In the fight against gray spot, copper-containing preparations will help, including: "Skor", "Kuproksat", "Fundazol". When the disease is detected at the initial stage, it is possible to carry out treatment with biological fungicides, for example: "Fitosporin", "Gamair", etc. However, in the absence of an effect and an increase in the area of lesions, it is nevertheless necessary to switch to chemical preparations.
Viral ring mosaic.
Typically, the viral mosaic attacks plants in the spring. If a tree is affected by this disease, then with a high probability, sooner or later, you will have to get rid of it. The virus enters plants at the cellular level and cannot be cured. The disease manifests itself on the leaves, they are covered with alternating yellow spots of irregular shape, more often, in the form of oblong rings. Then the leaves wither, dry and fall off.
Prevention of this disease is the treatment with "Alirin". Moreover, in addition to spraying the plant, the solution of the drug must also be added to the soil of the trunk circle.
It should be noted that fungal diseases affect plants much earlier than we see signs of infection.
The bodies of this pathogenic microorganism, for example, are formed in the second half of summer and remain on the affected plants or their remains until spring. The spring breeze easily spreads the spores of the fungus, populating plants with them, while the characteristic signs of the disease become visible only by mid-July.
So, on the leaves, sometimes on both sides, a white, cobweb-like bloom appears. It spreads especially quickly on young plants, affecting their shoots as well. If yellow, brown or black dots are visible on the leaves, then the degree of infection is already high. Such drugs as "Previkur", "Fundazol", "Acrobat MC" have an effective effect on the fungus, stopping its development and the processes it starts in plants. Treatment with drugs is carried out from one to four times by spraying plants with a frequency of 8-10 days.
Rowan is a fruit tree, so Monoliosis or fruit rot does not bypass it either. Pathogenic fungi, which are the causative agents of Monoliosis, further provoke another disease - necrosis that affects the leaves and berries of mountain ash.
Microorganisms are carried by insects, get on plants with wind and rain. In the winter, the causative agent of the infection settles in the stalks and, with the arrival of warm weather, spreads over the plants.
In this case, a biological fungicide - "Fitosporin-M" will be effective to fight the disease. Some gardeners practice the treatment of a plant with an iodine solution, for the preparation of which 10 ml of the drug is diluted in 10 liters of water. The treatment is repeated at least every 3 days and at least 3 times.
The main preventive measure is to preserve the integrity of the berries and shoots. If possible, they should not be damaged by birds, insects, garden cutting tools, etc.
Many gardeners are probably familiar with the signs of the disease - these are small rounded dark spots, on which plaque appears over time, where the spores of the pathogenic microorganism are located. The causative agent of the infection lives in fallen leaves and plant debris, and is especially active after a period of prolonged rains. Traces of his presence can be found already at the beginning of summer.
To get rid of the scab, all parts of the plant affected by it, including: leaves, branches and berries, including fallen ones, are removed and burned. Then, repeatedly, treatment is carried out using a chemical fungicide.
In the future, as a prevention of the appearance of scab, it is necessary to regularly weed and loosen the near-trunk circle.
Rust is most likely to infest the mountain ash if a juniper grows next to it. The fact is that first the infection affects the juniper, on the tissues of which growths are formed. It is from these outgrowths that the spores of the rust fungus spread to other plants and shrubs, infecting them too.
The signs of the disease are clearly visible on the foliage. Oval spots of a characteristic color appear on the upper side of the leaf plate, and spore outgrowths form below.
Treatment of affected plants is carried out not only with chemical fungicides, but also with agents that include sulfur, for example, "Cumulus".
Mountain ash necrotic diseases.
It is almost impossible to detect pathogenic fungi - the causative agents of Non-Tyreous necrosis at the initial stage. Often, the signs of the disease are species only when fungal growths, the so-called stroma, which have a pink color, protrude through the cracked bark. Their appearance means the death of that part of the branch or trunk where they are found.
The affected parts of the tree can only be cut and burned. And for the purpose of prevention, treat rowan with Bordeaux liquid, which has a protective and antiviral effect.
This type of necrosis spreads much faster than the previous disease. The necrotic tissues are oval in shape and, over time, become covered with bark. In a short time, these formations are able to completely encircle a branch or a thin trunk.
Many small tubercles begin to grow under the bark, the tops of which protrude to the surface. In spring or summer, you can see a certain mucous mass - these are spores of the fungus - the causative agent of the infection.
A tree infected with cytosporosis cannot be cured; it is cut down and burned to prevent infection of other plants and shrubs.
Prevention of the appearance of cytosporosis, as in the previous case, is spraying rowan with Bordeaux liquid. It is important to carry out the treatment before bud break, so the likelihood of the destruction of pathogens at the initial stage increases. By the way, this tool will contribute to a longer storage of the crop and preservation of its quality, if a tree is sprayed a month before picking the berries. In addition, it should be borne in mind that the concentration of the working solution used at the stage of early treatment and subsequently will be different. Also, you should remember about the need to comply with safety measures when working with the drug.
Necrosis of this species is also of fungal origin. The trunk of an infected tree turns yellow and the bark cracks. Over time, the number of cracks increases, they grow and the bark lags behind the trunk, branches. The wood darkens and the wood gives off an unpleasant odor.
Unfortunately, this necrosis is one of the diseases that cannot be treated. Rowan tree affected by Black Necrosis is cut down and burned. Therefore, in the fight for a tree with necrotic diseases, the prevention of their appearance comes to the fore. In addition to early treatments, the tree should be inspected regularly and the affected areas should be removed in a timely manner to avoid spreading the disease to other plants.
Mountain ash pests. Control and prevention measures.
The number of insects related to mountain ash pests is quite impressive - about 60 species. These are ticks, beetles, butterflies and other insects. The vast majority of them are polyphages, in other words, they are omnivorous. That is, they can migrate to mountain ash from other plants, where they have already affected the buds, leaves, fruits, shoots, etc. But the measures to combat them are different and are taken depending on one type or another.
A characteristic feature of the insect is the elongated part of the head, for which it received this name. For the same reason, the insect is also called an elephant. Weevil is a small beetle belonging to one of the largest families, numbering more than 50 thousand species. Of these, on the territory of Russia, there are about 5 thousand species. The insect hibernates in the bark or in fallen leaves. With the onset of spring, when the air temperature reaches +10 .. + 12 degrees, the insect crawls out of the shelter, settling on a tree. At first, the weevil feeds on the buds, and after the appearance of the foliage, it passes on to it, gnawing holes in the leaf plates. Damage to the leaves affects the processes of photosynthesis occurring in the plant, and, in large areas of damage, also on the vegetation processes of the tree.
In the spring, it is necessary to regularly inspect the tree and, if weevils are found, shake them off, first spreading a cloth or film under the tree, and then destroying them. You should also spray the tree with a solution of "Karbofos", since there is a very high probability that the beetle has already managed to lay eggs, from which, later, larvae will appear. In order to prevent the appearance of a weevil, treatment with copper sulfate can be carried out.
It is a small beetle, the size of which does not exceed 1 cm. The bark beetle is a typical tree-eating insect that lives under the bark. The beetle sharpens wood, making its way to its most juicy and vital layers. By the way, one of the signs of damage to a tree by a bark beetle is drill meal, which remains on the surface after the beetle sharpens its moves. The bark beetle is also dangerous because it can carry spores of pathogenic fungi into the deep layers of wood.
In the fight against the bark beetle, it is recommended to use the drug "Aktara", which is quite effective and well known to many gardeners.You can also carry out the treatment with solutions of "Confidor", "Lepidocide", spraying the tree after the end of flowering and, then, again after 15-17 days. In addition, it is recommended to keep the trunk circle clean, ensuring its regular weeding and loosening.
The main harm is caused by moth caterpillars, eating fruit trees, which include Rowan... Insects are especially active during the flowering period, attacking plants, they gnaw its flowers, buds and leaves. After the end of flowering, the caterpillars go into the soil, where they pupate. In autumn, butterflies appear from pupae, which are dangerous in that they lay eggs under the bark of a tree and in spring the entire cycle of their development is repeated.
To combat moths, the treatment is advised to be carried out before the flowering of mountain ash, using "Chlorophos", "Karbofos", as well as "Cyanox".
In early spring, you can spray the tree with a solution of copper sulfate. For its preparation, 100 grams of the substance is dissolved in 10 liters of water. And so, in order to be guaranteed to get rid of the presence of the moth, before the buds bloom, the tree is treated with Nitrafen.
This is a rather small insect, which can not be noticed with the naked eye, only the damage caused to it will be visible. On the leaf, on both sides, turrets appear - Gauls, brown. Such formations on the leaves disrupt photosynthesis, as a result, the tree does not receive the required amount of nutrients. This, in turn, affects its growth and development.
The gall mite is very prolific, it gives up to 3, 4 generations per season and hibernates easily in fallen leaves.
The most effective drug in the fight against this pest is a solution of colloidal sulfur. To prepare the working solution, about 100 grams of the drug are diluted in 10 liters of water. The resulting solution is sprayed on both the trunk and branches.
In order to prevent its appearance, it is necessary to remove fallen leaves in a timely manner and loosen the soil of the trunk circle.
This insect prefers rowan fruits. The butterfly lays eggs directly on the ovary. The larvae emerging from the eggs damage the berries, feeding on their pulp and making moves.
In the fall, the caterpillars go into the ground, where they spend the winter and pupate. In the spring, small butterflies appear, the wingspan of which does not exceed one and a half centimeters.
To combat the pest, in the last days of June, the tree is treated with chlorophos solution, at the rate of 20 grams per ten-liter bucket of water.
As you can see, such preventive measures as timely cleaning and burning of fallen leaves, loosening the soil to a depth of at least 10 cm will help keep the tree from being damaged by many pests, and the mountain ash moth is no exception.
As you know, aphids feed on plant sap. The rowan aphid sucks the juices from the green shoots, buds and leaves of the tree. As a result, dried leaves, deformed and twisted shoots, in which the processes of movement of nutrients and moisture are disrupted, and, accordingly, a weakened tree.
Aphids lay their eggs directly on the young shoots of the tree, where they spend the winter. Therefore, this pest must be dealt with exclusively with insecticides. Spraying with solutions of Aktellik and Decis preparations is effective against rowan aphid.
Despite its name, this pest does not refuse from rowan berries. It is a rather small insect, dark brown in color with transparent wings. Its larvae grow up to one and a half centimeters in length, have a shiny, wrinkled yellow body. It is the larvae that cause the greatest harm, affecting rowan berries.
The larvae hatch after one or two weeks, from the eggs, which the female of the insect lays on the fruit ovaries of the mountain ash. Fertility of the female is 60-80 eggs. The larvae spend winter in the soil.In the spring, when the soil warms up to a temperature of +12 .. + 15 degrees, the pupation process begins, which takes a little more than two weeks. Sawflies are quite active even at an air temperature of +16 degrees.
It should be noted that in the fight against this insect, you can do without chemicals. Gardeners advise using an infusion of white mustard powder. To prepare the infusion, 10 grams of powder is poured with one liter of water and left for a day. To make a working solution for spraying, the resulting infusion is diluted with water in a 1: 5 ratio (that is, 1 part of the infusion to 5 parts of water).
This is a small insect, which got its name due to the presence of a kind of shield, consisting of a huge number of hairs. The main damage to the plant is caused by the larvae feeding on its juice. With a massive invasion of the scale insect, all branches can be strewn with it. Its presence in such an amount causes the death of shoots and the subsequent death of branches. In extremely advanced cases, the death of the entire plant cannot be ruled out.
To combat the pest, the tree is sprayed with insecticidal preparations. However, before processing, you should carefully read the instructions, otherwise all efforts made and spent funds will be in vain. For example, some drugs will start working only when certain weather conditions occur. For example, such a remedy as "Prophylactin", used against scabbards, is effective at an air temperature of at least + 4 degrees. Also, experts recommend alternating the preparations with which the treatments are carried out so as not to cause some adaptation to the agent in insects and thereby reduce its effectiveness.
Also, you should remember about regular loosening of the soil, especially in the autumn period when preparing the garden for winter, as well as cleaning fallen leaves.
As you can see, it is not at all difficult to prevent the defeat of mountain ash by diseases and pests. Minimal care, consisting in regular inspections of the tree, weeding the tree circle, loosening it and cleaning the fallen leaves, will avoid many problems and keep the tree healthy. And mountain ash, in turn, will keep us healthy.