Scab on an apple tree: how to treat and how to fight, treatment with drugs and remedies

The problem of many gardeners is pests and diseases of fruit trees. Scab on an apple tree is one of the most common diseases caused by the fungus Venturia unequal. The proposed material provides a description of the specified disease, chemical and folk remedies and the procedure for processing.

Description of the disease and causes of occurrence

Scab is one of the most common diseases of fruit trees, manifested by characteristic formations on the leaves of the apple tree. If timely measures are not taken, it leads to damage to the tree.An apple, after exposure to a fungus, looks shriveled and loses its palatability significantly.

The fungus is transmitted in the following ways:

• atmospheric moisture;
• wind;
• insects.

Scab allows the tree to grow and develop, contributing to the spread of the disease, since it does not interfere with the process of photosynthesis. The fungus overwinters in fallen leaves and tree bark, continuing to live with the onset of spring.

The appearance and development of the disease is facilitated by a large amount of rain in the spring, excessive shading of the garden. As with any fungus, unequal venturia requires high humidity, warmth and shade to develop.

Lessons

Scab affects the tree completely, starting with the leaves, then moving on to the bark, young shoots and fruits. The disease is especially dangerous for young trees - it can lead to the death of an apple tree.

Damaged foliage falls off, the disease, spreading, passes to the bark and young shoots, then to the fruits. The bark cracks and swells, the shoots begin to wither, the fruits shrivel.

Signs of scab

Characteristic signs of the disease:

• in the beginning, small spots of olive color with a greenish tinge appear on the leaves of the tree;
• over time, the spots become larger, they blacken and crack;
• similar marks appear on young shoots and bark, in which cracks and swellings appear;
• with the appearance and growth of fruits, they also become covered with similar spots, wrinkle and lose their visual appeal.

The duration of the incubation period of the fungus, depending on the resistance of the variety and the accompanying conditions, is from six to twenty days. The listed external signs begin to appear after a specified period after infection.

Chemicals

If timely measures are not taken to treat the disease, the yield of the garden will significantly decrease, the size of the fruits will decrease, their appearance will deteriorate and the content of vitamins and other useful substances will decrease. In a short period, the disease can affect up to ninety percent of the garden, which is especially dangerous for young trees.

The following are the most effective chemicals for scab control.

Abiga Peak

This is an antifungal fungicide. They treat trees not only for treatment, but also for the prevention of disease. The therapeutic effect is exerted by active copper, which is formed after spraying and blocks spores, in connection with which obstacles are created in their reproduction and distribution. This tool has the following benefits:

• versatility of application;
• moisture resistant, won't wash off when it rains;
• large spread over the processing area;
• compatibility with other products;
• minor environmental hazard.

The drug does not change the taste and appearance of processed fruits. The product is available in bottles of forty to fifty grams. To prepare the mother liquor, the contents of the container are diluted based on one liter of water. The resulting composition, for use, is diluted in a ratio of one to ten.

Oxychom

This drug has a similar mechanism of action, but is characterized by the presence of two substances:

• copper ions, causing the death of the pathogen;
• oxadixyl, absorbed by foliage and blocking synthesizing processes in the mycelium of the fungus.

Like the previous remedy, the use of oxychoma contributes to the treatment and prevention of the onset of the disease. In addition to high efficiency, the drug has the following advantages:

• long period of protection;
• fast response speed - within two hours of processing.

However, there are also disadvantages. The medicine is not always compatible with individual drugs, especially with the alkaline group.

Pay attention! Oxychom is a substance of the first hazard class, therefore, when used, appropriate precautions and protective equipment must be used.

The drug is available in powder form, five-kilogram packs. For use in ten liters of water, dilute up to fifteen grams of the drug.

Kuprikol

Many gardeners prefer to get rid of scab with Kuprikol. The tool is produced by a colloidal solution with an active substance content of two hundred grams. This form makes it easy to dissolve the drug for use.

Kuprikol is highly effective against fungal diseases, including scab, does not affect the development of the apple tree. During the season, it is necessary to process the tree up to six times. The drug is resistant to atmospheric moisture, highly soluble in the preparation of the composition. Can be used in combination with other products.

Cuprostat

A similar tool to save the garden from scab. The preparation consists of:

• nineteen percent copper;
• for sixteen - from ammonia;
• 26 - from acetic acid.

The drug has the same benefits and mode of action as above. Environmentally friendly product, does not pose a danger to humans and animals. Use with caution near stocked waters.

Produced in liquid form, in canisters of ten and twenty-five liters. More effective in the early stages of the disease. When the disease spreads, the effectiveness is greatly reduced.

For spraying it is necessary to choose a clear, quiet day, the wind speed should not exceed six meters per second. The frequency of processing per season is about three times. The last spraying before harvesting should be done a month in advance to eliminate the presence of harmful substances in the fruit.

Tsikhom

Another drug based on copper oxychloride. Another active ingredient is cineb. The principle of operation is similar to the above means. The effect appears immediately after spraying, the duration of protection is up to twelve days.

Combines well with other products. The processing interval - taking into account the duration of protection - is about twelve days. When processing fruit trees from scab, the drug consumption rate is from six to eight kilograms per hectare.

Produced in ten-kilogram bags, in powder form. Not too dangerous for humans (second class), a greater degree of danger for insects (bees and others).

A week after spraying in the garden, manual work is allowed, mechanized - after three days.

Colloidal sulfur solution

One of the most time-tested drugs. Unlike the above remedies, it does not require penetration into the plant to obtain the desired effect.

Sulfur contained in the composition counteracts the fungus, is favorable for the growth and development of crops, it is one of the necessary components for plant vegetation.

Processing with a solution should be carried out no more than five times during the season. Thirty to eighty grams of the drug is mixed in a bucket of water, depending on the stage and extent of the infection.

It is recommended to treat trees prophylactically and after the first signs of disease appear.

Pay attention! Sulfur is a flammable substance, this should be taken into account when organizing the storage of the drug.

The composition is evenly distributed over the surface of the trees. Sulfur interferes with the respiratory function of the fungus, causing its death. Despite the relative safety for humans (third class), it is necessary to apply appropriate precautions - work in respirators, do not eat or smoke during processing, do not spray in windy weather.

This remedy is one of the simplest and most effective against scab.

Cumulus

Kumulus is another name for the above drug, which is no different from it. The choice of the name of the drug depends on the manufacturer, but the composition of these drugs is similar.

Thiovit Jet

Another contact fungicide with a wide range of applications. Swiss analogue of colloidal sulfur, which has a more lasting effect and has proven itself well in Russian conditions.

Duration of action of the drug - up to ten days after spraying. The specified period may vary, depending on the development of the disease, the level of atmospheric humidity, wind strength and other indicators.

The ratio of dilution of the substance with water is similar to the above remedy. The solution is thoroughly mixed until completely homogeneous. The number of sprays during the season - up to six times.

The product has a moderate degree of danger (third class), but the inhalation of the substance is undesirable.

The medicine is produced in granules packaged in 30-gram bags. Available in 20kg bags for large scale use.

Biological bacterial fungicides

Some soil bacteria counteract fungal pathogens. Therefore, scab can be treated using the following biological bacterial fungicides:

• Planriza - products based on these microorganisms, effectively counteracting scab and destroying the fungus, contributing to the development of plants. In the process of reproduction, bacteria protect crops from diseases and release nutrients that help increase yields;
• Trichodermina is a biological agent that uses the opposing fungus of the same name.Parasitizing on the causative agent of the disease, it leads to its destruction; the effectiveness of the drug is not affected by the level of humidity, but the ambient temperature is important, it must be at least fourteen degrees;
• Phytobacteriomycin - produced in two-, five- and ten percent powder with a high degree of antifungal efficacy. It is characterized by an average level of toxicity;
• Pentafage - a tool based on a complex of five strains of bacterial viruses and biologically active components. In the process of decomposition of the components of the drug, new strains are formed that contribute to the destruction of the fungus. It is used in the form of an aqueous suspension, at a concentration of up to five percent, depending on the stage of development of the disease;
• Gaupsin - a universal remedy against fungal diseases and pests.

All biologics have the following benefits:

• high biological activity;
• increasing plant immunity against diseases;
• improving crop nutrition, soil structure and fertility.

Pay attention! Unlike chemicals, biological agents do not act as quickly, but the duration of protection is much longer, as is the concomitant positive effect of their use.

Systemic fungicides

Under the systemic impact is meant that the drug affects the fungus not only at the site of application, but also redistributed throughout the tree, including inside the tissues. These remedies should be used until the disease has spread, but after treatment, the drug continues to act, regardless of environmental conditions, not washed off by rain and drought.

The duration of the effect is significantly higher compared to contact ones - up to three weeks. However, when re-treatment, it is necessary to choose a drug from a different group, since the fungus adapts to the drug.

Next - more details about the individual chemical groups of systemic fungicides.

Preparations of the strobirulin group

The initial funds of this group were derived from the fungus of the same name, which penetrates the infection and prevents the pathogen from breathing, causing its death.

It is recommended to apply these funds before all others. To exclude adaptation of the fungus, no more than two treatments should be carried out during the season.

Drugs of the triazole group

The mode of action is similar to the above drugs. It is characterized by the rapid onset of the effect of the application, the product is instantly absorbed, so already half an hour after spraying the rain will not affect the result.

The drug promotes plant growth by accelerating the process of photosynthesis. One of the few drawbacks is a quick addiction, so you need to switch to other groups of fungicides.

Copper sulfate solution

The indicated remedy is copper sulfate. It is recommended to use it before the opening of the kidneys, during the initial treatment in the early spring. Substance consumption - one gram per square meter; the solution is diluted at the rate of one hundred grams of the drug per ten liters of water. Processing is carried out from the bottom of the trunk to the top of the crown. The greatest efficiency is observed when spraying once every five years.

Benzimidazoles

Preparations of this group interfere with the process of fission of the nuclei of the fungus, preventing its reproduction and the development of the disease. These are broad-spectrum agents characterized by a long period of protection. Not only trees, but also harvested fruits are treated with the medicine to prevent the development of the disease during transportation.

Chorus

A relatively new drug that has gained popularity among gardeners. It is distinguished by its ability to prevent the development and occurrence of infectious plant diseases, protects and heals trees.

Lack of medicine - low efficiency with a strong degree of development of the disease - for adult trees. It is characterized by local impact, therefore, to ensure the effectiveness of the drug, it must be applied, distributed over the treated surfaces.

Spraying should be done at the beginning of the growing cycle. Effective over a temperature range of three to twenty-five degrees.

Fitosporin M

The newest remedy, effective at any stage of the development of the disease. Created on the basis of a spore culture that suppresses the reproduction of pests. The main drawback of the drug is the instability of the bacterium in natural sunlight, so cloudy weather should be chosen for processing.

Folk remedies

Many gardeners fight scab with folk methods that involve:

• timely cleaning of fallen leaves and fruits to prevent the spread of infection. They are buried in the ground or used to make compost;
• sprinkling with a solution of mustard - eighty grams of the powder is dissolved and injected into ten liters of water. The tree itself and the near-stem zone are processed. Several treatments needed starting in May;
• treatment with potassium permanganate - five grams of powder per bucket of water. The method is identical to the previous one;
• spraying with saline - based on a bucket of water - one kilogram of s alt; produced in early spring, before buds swell;
• application of horsetail tincture - a kilogram of fresh grass is poured with five liters of boiled water, infused for three days. The resulting composition is diluted in a ratio of one to ten. Processing is carried out after the appearance of the first leaves;
• using whey - the composition is filtered through gauze, the whole tree is sprayed, a very effective remedy at any stage of the development of the disease.

Pay attention! Folk remedies are effective in the initial stages of the development of the disease or as a preventive measure, but are not effective for serious infection.

Features of the struggle at different times of the year

Primary processing of trees is carried out in early spring, before the start of the growing season. In summer, in June and July, the garden is re-sprayed with chemical and biological preparations. Substances are combined to eliminate the habituation of the fungus. It is necessary to observe the frequency of treatments, taking into account the duration of a particular drug.

An important factor in the development of the disease in the summer is the weather. If low humidity is established, accompanied by high air temperature, the development of the disease stops. This should be taken into account in determining the frequency of treatments.

Summer spraying should be done early in the morning or late in the evening to avoid burning the leaves with the drug and its premature evaporation without any effect.

In autumn, treatment is carried out after the removal of fruits; to consolidate the achieved effect, it is necessary to remove the affected branches and leaves.

When fighting the disease, it must be taken into account that infection from untreated trees located in a neighboring area is possible. The spores of the fungus can be carried by the wind from the affected garden.

An important measure to counteract scab in the autumn is the fight against insects that carry the disease. They hibernate in the near-stem zone, penetrating trees with the onset of spring and spreading the infection. A circle near a tree, up to two meters in diameter, must be cleaned of pests and treated with pesticides before the onset of cold weather.

How to treat during fruiting

Control measures during the fruiting period include the use of traditional methods or environmentally friendly biological products to prevent the accumulation of toxins in the fruit.

Two weeks before harvest, processing must be excluded. Trees are sprayed immediately after fruit picking.

Consequences

If timely measures are not taken, the development of the disease leads to a decrease and wrinkling of the fruit, a decrease in the content of useful substances in them. The growth and development of the tree slows down. Intense infection can destroy young shoots, up to the death of seedlings.

Prophylactic treatments for apple trees

The development of the disease is easier to prevent by taking appropriate preventive measures.

Spring processing

In the spring, you need to produce:

• introduction into the near-stem circle, up to one meter in diameter, organic fertilizers in accordance with established standards;
• digging the soil in the garden with preliminary cleaning of last year's foliage and fallen branches;
• abundant watering - at least fifteen liters for one tree;
• treatment of wet soil with urea, potassium chloride or ammonium nitrate;
• whitewashing trunks with lime to a height of up to one meter;
• spraying branches and trunk with Bordeaux mixture.

The above activities are carried out before the first buds open.

Autumn processing

Before winter, it is necessary to remove dry branches and leaves from trees, collect and bury or burn fallen leaves to prevent spores from overwintering with subsequent infection in the spring. Trees are treated with chemical, bacteriological or folk remedies.

As can be seen from the presented material, scab on an apple tree is a serious disease that negatively affects the development of trees and leads to a complex damage to the crop. Therefore, adequate measures must be taken to prevent and treat the disease in order to ensure a high yield and normal development of trees.

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