Signs and treatment of scab on an apple tree, how to deal with drugs and folk 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 Venturia Unequal fungus. The proposed material provides a description of the specified disease, chemical and folk remedies and the procedure for processing.

Description of the disease and the cause

Scab is one of the most common diseases of fruit trees, which manifests itself as characteristic formations on the leaves of the apple tree. If you do not take timely measures, it leads to damage to the tree. The apple, after exposure to the fungus, looks shriveled and significantly loses its taste.

The fungus is transferred in the following ways:

• atmospheric moisture;
• by the wind;
• insects.

The scab allows the tree to grow and develop, contributing to the spread of disease as it does not interfere with photosynthesis. The fungus hibernates in fallen leaves and bark of trees, continuing its vital activity with the onset of spring.

The appearance and development of the disease is facilitated by a large amount of rain in the spring, excessive shade of the garden. As with any fungus, unequal venturia require increased humidity, warmth and shade for development.

Lesions

Scab affects the tree completely, starting from 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 the apple tree.

The damaged foliage falls off, the disease spreads to the bark and young shoots, then to the fruits. The bark cracks and swells, the shoots begin to fade, the fruits shrivel.

Signs of scab

Typical signs of the disease:

• first, small spots of olive color with a greenish tint appear on the leaves of the tree;
• over time, the spots become larger, they blacken and crack;
• similar traces 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 the 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 worsen 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 scab chemicals.

Abiga Peak

It is an antifungal fungicidal preparation. Trees are treated with it not only for treatment, but also for the prevention of disease. The active copper, which forms after spraying and blocks spores, has a healing effect, and therefore there are obstacles to their reproduction and distribution. This tool has the following advantages:

• versatility of application;
• resistant to moisture, does not wash off during rain;
• wide spread over the processing area;
• compatibility with other means;
• an insignificant environmental hazard.

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

Oxyhom

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

• copper ions, causing the death of the causative agent of the disease;
• oxadixil 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 after treatment.

However, there are also disadvantages. The medicine is not always compatible with certain drugs, especially for alkaline drugs.

Note! Oxyhom is a substance of the first hazard class, therefore, when applied, appropriate precautions and protective equipment must be used.

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

Cupricol

Many gardeners prefer to get rid of scab with Cuprikol. The product is produced in a colloidal solution with an active ingredient content of two hundred grams. This form allows the preparation to be easily dissolved for use.

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

Cuprostat

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

• nineteen percent copper;
• sixteen - from ammonia;
• twenty-six - from acetic acid.

The medicine has similar benefits and mode of action as above. An environmentally friendly product that does not pose a danger to humans and animals. It should be used with caution near stocked reservoirs.

It is produced in liquid form, in cans of ten and twenty five liters. More effective in the early stages of the disease. With the spread of the disease, the effectiveness is significantly reduced.

For spraying, you must 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 one month in advance to eliminate the presence of harmful substances in the fruits.

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Tsikhom

Another preparation based on copper oxychloride. Another active ingredient is zineb. The principle of operation is similar to the above means. The effect is manifested 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 treating fruit trees from scab, the consumption rate of the drug is from six to eight kilograms per hectare.

It is produced in 10-kilogram bags, in powder form. Not too dangerous for humans (second class), it poses a great degree of danger to insects (bees and others).

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

Colloidal sulfur solution

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

The sulfur included in the composition counteracts the fungus, is favorable for the growth and development of crops, it is one of the necessary components for the vegetation of plants.

Treatment with a solution should be carried out no more than five times during the season. From thirty to eighty grams of the drug is stirred in a bucket of water, depending on the stage and degree of spread of the infection.

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

Note! 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 it to die. Despite the relative safety for humans (third class), appropriate precautions must be taken - 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

Cumulus 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.

Tiovit Jet

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

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

The drug is distinguished by a moderate degree of danger (third class), but the ingestion of the substance into the respiratory tract is undesirable.

The medicine is produced in granules, packaged in thirty-gram bags. For large-scale use, it is produced in twenty-kilogram bags.

Biological bacterial fungicides

Some soil bacteria work against fungal pathogens. Therefore, scab can be cured using the following biological bacterial fungicides:

• Planriza - means based on the indicated microorganisms, effectively counteracting scab and destroying fungus, promoting the development of plants. In the process of reproduction, bacteria protect crops from diseases and release nutrients that help to increase yields;
• Trichodermina is a biological agent that uses the 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 should be at least fourteen degrees;
• Phytobacteriomycin - produced in two, five and ten percent powder with a high degree of anti-fungal effectiveness. It is characterized by an average level of toxicity;
• Pentaphage - a drug 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, with a concentration of up to five percent, depending on the stage of development of the disease;
• Gaupsin is a universal remedy against fungal diseases and pests.

All biological products have the following benefits:

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

Note! Unlike chemical agents, biological agents do not act so quickly, but the duration of protection is significantly higher, as well as the concomitant positive effect from their use.

Systemic fungicides

The systemic effect means that the drug affects the fungus not only at the site of application, but is also redistributed throughout the tree, including inside the tissues. These funds should be used until the disease has spread, but after treatment, the drug continues to act, regardless of environmental conditions, without being washed off by rains and drought.

The duration of the effect is significantly longer compared to contact, up to three weeks. However, when reprocessing, it is necessary to choose a drug of a different group, since the fungus adapts to the drug.

Further - in more detail about the individual chemical groups of systemic fungicides.

Preparations of the strobirulin group

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

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

Triazole group preparations

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

The medicine promotes plant growth by speeding up the process of photosynthesis. One of the few disadvantages is quick addiction, so it is necessary to switch to other groups of fungicides.

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Copper sulfate solution

The specified agent is copper sulfate. It is recommended to use it before the kidneys open, during the initial treatment in the early spring period. 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.

Preparations of benzimidazole groups

Preparations of this group interfere with the process of division 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 are treated with medicine, but also the harvested fruits, to prevent the development of the disease during transportation.

Horus

A relatively new drug that has gained popularity among gardeners. Differs in the ability to prevent the development and emergence of infectious diseases of plants, protects and heals trees.

The disadvantage of the drug is low efficiency with a strong degree of disease development - for adult trees. It is characterized by the localization of the 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 in the temperature range from 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 bacteria in natural sunlight, therefore, cloudy weather should be selected for processing.

Folk remedies

Many gardeners are struggling with scab with folk methods that involve:

• timely cleaning of fallen leaves and fruits to prevent the spread of the infection. They are buried in the ground or used to make compost;
• spraying with mustard solution - eighty grams of powder is dissolved and injected into ten liters of water. The tree itself and the near-stem zone are processed. Several treatments are 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 salt; produced in early spring, before the buds swell;
• the use 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;
• the use of 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.

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

Features of the fight at different times of the year

The primary processing of trees is carried out in early spring, before the beginning of the growing season. In summer, June and July, the garden is re-sprayed with chemical and biological agents. The substances are combined to eliminate the addiction 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 a high air temperature, the development of the disease is suspended. 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 in order to exclude burns of the leaves by the preparation and its premature evaporation without exerting an effect.

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

When fighting the disease, it is necessary to take into account that infection is possible from untreated trees located in a neighboring area. Fungal spores can be carried by the wind from the affected garden.

An important measure of countering scab in the autumn is the fight against insects that carry the disease.They winter in the near-stem zone, with the onset of spring they penetrate trees and spread the infection. A circle around a tree, up to two meters in diameter, must be cleared of pests and treated with pesticides before the onset of cold weather.

How to heal during fruiting

Control measures during the fruiting period include the use of folk methods or environmentally friendly biological products to exclude the accumulation of toxins in the fruits.

Two weeks before harvesting, processing must be excluded. Spraying of trees is carried out immediately after harvesting.

Effects

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

Preventive treatments for apple trees

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

Spring processing

In the spring, it is necessary to produce:

• application of organic fertilizers to the near-stem circle, up to one meter in diameter, in accordance with the established norms;
• digging the soil in the garden with preliminary harvesting 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 of trunks with lime to a height of one meter;
• spraying branches and trunk with Bordeaux mixture.

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

Autumn processing

Before winter begins, it is necessary to remove dry branches and leaves from trees, collect and bury or burn the fallen leaves in order to exclude the wintering of spores 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 culture. Therefore, adequate measures must be taken to prevent and treat the disease in order to ensure high yields and normal development of trees.