In almost every region, apple trees are prone to such an insidious disease as scab. It causes irreparable damage to the garden, reducing the yield and winter hardiness of the tree. Every gardener should know how to recognize the disease, what measures to take if the trees are already affected by scab.
In this article, we just consider these relevant issues. We learn how to deal with scab on an apple tree, how to do it in summer and autumn, and also how dangerous this disease is for a tree.
Table of contents
What is scab: where does the disease on apples come from and is it harmful to humans?
First, we learn what a scab is and where it comes from. Scab is a fungal disease that is widespread throughout Russia. It is caused by marsupial fungi that affect not only the leaves, but also the fruits of the plant. The scab is very insidious, as it often disguises itself as other diseases, so for beginners in gardening it is difficult to determine reliably. This leads to outbreaks of the disease, which cause great harm.
The most common scab can be found in regions with a temperate climate, where it is especially wet and cold spring. In rainy summer scab can hit up to 90% of the garden. In addition, the disease not only reduces the yield of the tree, but also the performance of the fruit. Affected fruits are poorly stored, lose their vitamin value, become unattractive. The tree rarely dies from scab, but its winter hardiness decreases, which can lead to freezing.
Fighting scab is not easy, but necessary.The disease tends to move from one tree to another. If scab pathogens have settled in the garden, then all plants should be treated.
How can I identify a disease in apple trees?
To understand how to cure a garden, it is important to know how to identify a scab on apples. Disputes overwinter in unripe fruits and in fallen leaves. In early spring, when the humidity is high enough, spores dissipate. They are easily carried by the wind and birds, attached to the leaves of the plant. An outbreak of the disease occurs at high humidity.
The development of the fungus occurs on the apical leaves of the shoots at a temperature of about 12 degrees. At the initial stage, you can find subtle light olive spots or young leaves of the tree. This is how the disease develops. Already during this period it is necessary to begin the struggle with the disease. In the process of development on the leaves brown spots are formed, and the ovaries, pedicels and shoots become infected with fungus, and begin to rot.
Even after harvesting, the fungus continues to grow both in the fruit and on the fallen leaves. In autumn, the last stage of spore ripening takes place, which easily endures winter. Affected fruits deteriorate during storage, their keeping quality is reduced.The cunning of the disease is that it affects the garden throughout the season, even late varieties of fruit trees cannot withstand the disease.
If you miss the moment and do not fight the disease, then it goes to the fruits that are unsuitable for storage and processing.
What does it look like?
There are several reliable signs, in the presence of which you can talk about scab:
- the presence of round olive spots on young leaves of apple trees;
- in the case of spring damage, the size of the spots reaches 13 mm, and in the autumn the spots are much smaller, up to 2-3 mm;
- when the disease is neglected, dark spots of almost black color also appear on the fruits of the apple tree;
- as the fruits grow, the spots crack, their edges become light;
- the presence of a large number of ugly and small fruits on the tree;
- early fall foliage during spring infection;
- bark swells up on the tree, then it cracks and flakes;
- affected shoots slow growth and die.
As you can see, scab affects all parts of the tree, so it is difficult not to notice the disease.Apples look unpresentable and sometimes they do not want to eat at all.
Treatment methods for fruit trees in autumn and summer
To cure the scab on apples and prevent infection of other fruit trees, it is necessary to resort to comprehensive control measures. In the initial stages of the disease and as a preventive measure, you can use folk remedies.
When running the disease without the use of chemicals no longer do. How and what preparations to use, when to carry out treatments for scab - these are the main issues that concern gardeners.
You may also be interested in the following articles on the subject of apples:
How to get rid of the disease by chemical means: what to spray and process?
Before using chemicals, it is important to know the basic rules for their use:
- When spraying trees it is impossible to use the same preparation constantly. This is due to the fact that there is an adaptation of the fungus to the substance contained in its composition.
- Only fungicides of the 3rd and 4th class of danger are allowed on the plot. Use industrial preparations for the garden can not. Substances that are contained in their composition, can accumulate in the fruit and penetrate the skin, which harm human health.
- The treatment is carried out only with a special sprayer, distributing the mixture evenly over the surface of the tree.
- Spraying is carried out only with the use of personal protective equipment, as well as in favorable weather.
- Garden treatment of scab should be carried out in conjunction with preventive measures.
The most popular means in the fight against scab on apple and pear, which showed good results, can be considered the following preparations that can be processed apple trees:
- fungicide "Raek". The substances contained in the preparation, penetrate into all parts of the plant.The effect of the drug lasts for the next 3-4 weeks. The tool is resistant to washing off with rain. Up to 4 treatments are allowed per season. The first time spraying is carried out before blooming buds, then - during budding and after flowering. The last treatment is carried out during the formation of the crop, three weeks after flowering;
- drug "Skor". During the season, only two sprays are allowed using this drug. The validity of a substance on an apple tree is up to 20 days;
- "Horus". This drug has proven itself when the temperature drops to +3 degrees. It is resistant to washing with rain, the effect of the drug lasts up to 30 days. Processing is carried out two times: before bud break and after flowering;
- Complex fungicide "Strobe". Treatment with this drug is carried out three times, after which you need to apply different means from it. The strobe protects the tree not only from scab, but also other fungal diseases. The term of the drug - 35 days;
- Fitolavin. This drug belongs to the group of antibiotics. It is used against scab on fruit trees. During the season 4 treatments are allowed, the interval between which is 15-20 days.
Recently, biological products have been used in horticulture, which are less toxic but have a detrimental effect on the fungus. These include "Fitosporin", "Gamar".
How to deal with traditional methods and cure apple trees?
If the disease in the garden is not too common, then you can try to stop its development with the help of folk methods.
- At the first signs of the disease of fruit trees, the garden is treated with a solution of mustard. To do this, dry mustard powder is mixed with a small amount of water, then bring the solution to 10 liters of warm water. A freshly prepared solution is sprayed on an apple tree and stem circles. Processing should be carried out immediately after the rain. It is especially important to spray the apple tree in spring and early summer, when the disease can still be stopped.
- Good help from scab and potassium permanganate solution. After spraying on the leaves of the tree may appear dark harmless spots. Processing is carried out repeatedly.
Treatments for apple trees with mineral fertilizers can be attributed to folk remedies for scab. In spring, trees are sprayed with a solution of one of the fertilizers:
- potassium salt;
- potassium nitrate;
- ammonium nitrate;
- potassium sulfate.
In the autumn you need to spray the tree and the barrel circle with a solution of urea.
Prevention and protection of apple trees
Every gardener knows that it is much easier to prevent a disease than to cure it, so scab prevention is an important event. What to do to prevent scab damage on apple trees?
- Plant the most resistant to defeat varieties. It is important to remember that the same variety behaves differently in different climatic zones. Choose varieties that are suitable for the local climate.
- In autumn, all the fallen leaves, fruits and branches must be collected and removed from the site.
- With the onset of stable frosts, they dig up the soil around the trees so that the spores are not in favorable conditions.
- After harvesting, you need to clear the bark of the tree to healthy wood, then bleach the trunk, adding copper sulfate to the solution.
- A good preventive measure will be compliance with the cultivation of apple trees. Scab most often develops in dampness at thick plantings and unkempt trees,in too shaded places. Planted an apple tree in a well-lit place, in time to carry out sanitary cleaning of the garden.
Below is a short video on how to get rid of scab on apples:
Conclusion
The scab causes great harm not only to the apple tree, but also to the neighboring fruit trees in the garden. For a successful struggle and the preservation of the health of the garden, it is important to detect the disease in time and take all the necessary measures for complex treatment.
Every gardener should remember that disease prevention is half the success on the path to a healthy harvest. Do not neglect garden cleaning and preventive spraying. In case of more serious damage to the apple trees should be resorted to chemicals.