Scab on the apple tree is a common disease, trees die from it very rarely, but when the disease yields are greatly reduced.
Apples take an ugly shape, their size decreases, the amount of nutrients and vitamins decreases. Fruits are stored less, and their taste deteriorates, the tree loses attractiveness, and the winter hardiness of the apple tree decreases.
How does scab appear on the apple tree
Causative agent of the disease marsupial mushroom - unequal venturia, the disease is common in temperate regions and where cold and humid spring is possible. From scab, not only the quality and quantity of the crop is deteriorating, but also the apple tree.
Scab can appear on any apple tree, despite its variety, do not believe that any variety is immune to this disease. The defeat of the fruits can reach up to 90% and even up to 100% in areas with long summer rains - the North-West of our country and the North Caucasus, the disease affects the old apple trees more.
For the active development of the fungus, a humid environment is necessary, young leaves most affected at the ends of the branches. First, light spots become visible, after a while an olive coating appears on the surface of the spots, they gradually combine and begin to blacken, pedicels and ovaries are also affected.
Dark, rounded spots form on the fruits, in this area the apple tissue becomes solid, often it begins to crack. If the fruits fall ill at a young age, then they become not beautiful and crooked. The causative agent of the disease hibernates in uncleaned foliage, with the onset of spring heat, small black tubercles form on it, and spores mature there. Rainy weather greatly helps this process.
Attention! Over the summer, several generations of fungal spores ripen, infecting the remaining leaves and apples.
The disease develops rapidly in damp areas and in thickened landings, where ventilation is complicated.
Apple Scab Fight
The main thing in the treatment of this disease is the destruction of the source of infection - infected leaves. In the autumn of each year, after harvesting the fruits, you need to collect the fallen leaves and burn them. Affected apples must also be destroyed, the trunk circle near the apple tree must be dug up. So you can destroy the remaining leaves with the spores of the disease. If a lawn is broken under a tree, then it can be treated with a 10% solution of urea or ammonium nitrate. When the buds begin to bloom, the tree needs to be sprayed with a growth stimulant.
Dry branches need to be cut, areas where bark lesions are visible, need to be cleaned to healthy wood, after which they need to be whitened. If these methods do not help, then you will have to use chemicals. Several treatments over the summer will help contain the scab.
There are 2 processing methods:
1. Early in the spring, when young leaves begin to appear, it is necessary to process the trees with the composition "Skor". Dilute 1 ampoule of the drug in a bucket of water, another treatment is carried out after flowering, 4% solution of copper oxychloride or 1% copper sulfate;
2. "Blue spraying" - processing of apple trees with a 3% solution of Bordeaux liquid, with this treatment the apple trees become bright blue. Abundantly treat the most affected plants in early spring. This method is effective for young trees and in wet areas.
If the trees grow in a well-ventilated place, then they can be treated with 1% copper chloride. The first time the apple trees are sprayed during the formation of the buds, the second time is sprayed immediately after flowering, the third treatment is performed after 2-3 weeks.
Together with the Bordeaux mixture, a 2% solution of iron sulfate is sprayed, plants and the soil around the tree are sprayed with it. This must be done before budding, you can repeat the procedure to enhance the effect, but no later than 2 weeks before harvesting the fruits.
It must be remembered that the treatment must be performed in dry weather, in the morning or in the evening using protective equipment.
Some gardeners advise destroying the scab using saline, it is prepared by dissolving 1 kg of salt in a bucket of water. This treatment delays the vegetation of plants a little, but helps in protecting against frosts and in combating scab. Helps treating trees with infusion of horsetail, trees are treated in early spring, when the first leaves appear. In a bucket of water insist 3 days 1/3 of a bucket of horsetail.
It is important that your neighbors also use protective measures against scab, otherwise the infection may persist and come back to you.
Useful apple scab tips
When simple methods of control do not help, you will have to use chemicals. In this case, several rules must be followed:
• Trees are treated simultaneously with pruning infected leaves, shoots and fruits;
• In most cases, only 1 active ingredient is used in the preparations, for this reason the following treatment must be done with another agent so that the pathogen is not used to the chemical;
• Do not use tools intended for industrial use in the garden near the house;
• Apple trees are resistant to scab, they are treated for prevention in a favorable year for the disease, medium-resistant - once a year, the rest - several times a year.
Compliance with these rules will help to eradicate the disease, and will assist in prevention.
Preventive actions
In order to preserve the harvest and not treat the trees, it is better to carry out preventive measures in advance. This will provide an opportunity to save money, time and effort.
These works include:
1. It is advisable to plant apple seedlings in high places;
2. Trees cannot be planted densely, for good lighting and better ventilation, it is necessary to trim thickening crown and dry branches on time;
3. Choose varieties resistant to scab;
4. You need to monitor the amount of essential nutrients in the soil.
We must not allow the trees to starve and do not overfeed the plants with nitrogen.
Even after all the fruits are harvested, the fungus develops both on the harvested and remaining fruits, and on the flying leaves. In the autumn, spore maturation occurs, and diseased fruits are poorly stored. The insidious scab is that the trees suffer from it throughout the entire warm season, even varieties of late ripening are sick.
Prevention should begin in the fall, timely care of plants will make it possible to prevent the emergence and spread of the disease, or at least (in an unfavorable year) to reduce the negative impact.
Autumn prevention consists in collecting and destroying flying leaves, cleaning dead bark, removing damaged and dried branches, because on such material the fungus is waiting for the winter. The cleaned places are treated with a solution of copper sulfate (make a solution of 1 tbsp. L. Chemical in 1 liter of water) or just whitened cleaned places on the apple tree.
