You may have seen in your garden the consequences of a scab on an apple tree. How to deal with it, what methods and means to use to protect your trees, the fruits of the activities of this fungus-parasite? Alas, sooner or later, any gardener is faced with a similar problem, it is not easy to get rid of it, but it is still possible.
About apple scab
The scab is a Venturia inaequalis fungus that is activated under conditions of high humidity. Protracted rains, fogs, dampness - favorable conditions for its manifestation. With the arrival of early spring, the pathogenic fungus begins to attack the young shoots and bark, it clings to them, develops and moves to other parts of the tree. In the advanced stage, the disease causes significant damage to the crop, weakens the vitality of the fruit plantations, and young trees may even die from its invasion.
Traces of apple scab are very easily recognizable: on the ovaries, foliage and fruits first appear greenish-yellow, marsh-colored spots, which subsequently darken and become covered with cracks. Usually the disease begins with the defeat of young leaves, which are located on the top of the shoot - they are most vulnerable. At first, the bright spots are not visible, but over time they turn black, increase in size, merge with each other. Diseased leaves dry up and fall off, the affected areas on the fruit become hard, crack and gradually seize the whole apple.
The pathogenic fungus attacks all varieties of apple trees indiscriminately, most of all he likes thickened gardens and rainy weather, and the first and very young trees are the first to enter the risk zone. Diseases are trees growing in any region. The way out of this situation is active preventive measures, as well as detection of the disease at an early stage (removal of all affected fragments). To initially reduce the likelihood of the disease, experienced gardeners recommend choosing varieties resistant to the disease, which will be discussed a little later.
Scab on apples, photo:
Pictured looks like scab on apple trees
The fungus itself is very tenacious and can calmly winter in untidy foliage. That is why in the autumn it is necessary to scrape the fallen leaves into piles and take them out for the territory. If scorching foliage remains on the earth, then in early spring there will appear traces of the disease on it - small dark tubercles in which fungus spores mature.
The release of spores occurs almost constantly, and humidity only contributes to this process.
Throughout the summer scab fungus throws ripe spores that attack healthy fragments of wood. It is noteworthy that scab activity does not disrupt the process of photosynthesis, the apple tree grows, and the fungus continues to seize the bark, foliage and fruits. Not only is the quality of apples declining, but the tree itself becomes vulnerable to the winter cold, outwardly it looks weak and sick.
Scab on apple trees - how to treat?
A radical method of treatment is pruning of affected branches, destruction of foliage with traces of fungus. After harvesting, remove all affected fruits and branches, peel the bark so that only healthy tissue remains. Obligatory rule should be to clean the fallen leaves with the arrival of autumn, it is a kind of "incubator" for the fungus. The leaves must be burned or buried in the ground beyond the boundaries of the site (if the terrain allows), the soil in the area around the circle of the trunk circle should be carefully dug. It is recommended to whitewash the trunks and sprinkle the crown with 5% solution of copper sulfate. If your tree grows on a green lawn, then it must also be treated with ammonium nitrate (10%).
Spring processing of scab from apple trees is carried out before budding, for this purpose they use Zircon (by the way, they can also irrigate trees in the fall, after harvesting). In the spring, dried branches are removed, the old bark is removed (the one that itself exfoliates), after which the stem itself is treated with whitewash. Wound spots on the branches are covered with garden pitch, and the finished powder diluted in water (sold in special stores) or an aqueous solution of lime with copper sulphate (5 kg + 1 l per 10 l of water) is used as a whitewash. After the apple trees ottsvetut, they should be treated with copper sulphate (1%), preparations "Tsineb" or "Kuprozan". After flowering, the tree is treated with Chorus, which is valuable because it is not afraid of rain, not washed off the branches.
Signs of the disease on the leaves, photo:
Also for these purposes you can use the drug "HOM" (4%), Bordeaux liquid (3%), "Homezin", "Vectra". Irrigation Bordeaux liquid should be abundant - such that the drug literally drips from the branches. In the people, this method is called blue irrigation, because after it the branches, leaves become bluish in color.
Prophylactic treatment of apple trees with the “Skor” systemic fungicide gives good results, it is very concentrated - 1 ampoule should be diluted in 10 liters of water.
Repeated treatment with the same drugs is carried out after 3 weeks or a month. In this case, the struggle consists not only in irrigating the trunk and branches, but also in the area of the near-stem circle, as well as the plants growing nearby.
Preventive treatment, photo:
Subsequent spraying is carried out with the arrival of stable warm weather, periodic treatment of scab in the summer suppresses the development of fungus and protects the trees. For these purposes, the fungicides Fludioxonil, Abiga-Peak, Hamair, and Raek are used. Doses and methods of dilution of drugs are always indicated on the package. Note that the last processing of apples must be carried out at least 15 days before the fruits are removed from the branches.
The drug "Fitoflavin" is used in the summer to create a reliable "shield" against the fungus, 3-4 irrigations are recommended for the entire season, the interval between treatments is 15-17 days (20 ml / 10 l of water). The Strobi fungicide also gives good results; during the summer season they can process trees up to 3 times, the interval between procedures is approximately 14 days.
How to treat apple trees from scab in the summer? If the situation is not too running, then it is better to use the "non-toxic" drug "Zircon". It is made on the basis of the plant purple echinacea, it is also its main ingredient. This tool does not adversely affect the environment, pets and people.
If the apple tree is seriously affected, then it makes sense to use more serious fungicides listed above. Do not forget about the means of protection during the processing of the garden, wear a mask and gloves. It is best to irrigate after rain, in the evening (or early morning), in calm weather.
How to process an apple tree from scab in June? At this time, it is best to use the environmentally safe drug "Fitosporin M" or "Baikal EM-1." These biofungicides strengthen the tree's immunity, are an excellent prevention against a wide range of fungal, bacterial diseases. Thus, the first stage of irrigation is carried out before the blooming of leaves, the second - before flowering, the third (most significant) - after the apple tree has faded. Treatment for scab in the summer is carried out (depending on the situation) every 2 or 3 weeks. If the summer was rainy, then the number of procedures should be increased to 5 or 6 times.
How to deal with scab on apples - on fungicides and fertilizers
First you need to understand the essence of the matter, the specifics of the "work" of fungicides. The fact is that different manufacturers produce products with different names, but most often the main active ingredient is common. When you acquire a fungicide, be sure to study its composition, because from frequent use of the same drug, scab can simply develop immunity to it.
To fight the fungus was effective, experienced gardeners recommend using at least two products with different "working" substance. Also pay attention to the hazard class of the drug, it is always indicated on the packaging. Level III and IV levels are recommended for suburban areas, and there - go at your own discretion. But keep in mind that chemicals for gardening farms is highly undesirable to apply at the dacha.
How to cure apple scab - an important point! Communicate with neighbors in the country, ask if their garden suffers from this fungus. The fact is that if the neighbors showed signs of illness, all your efforts, at best, will provide protection for only one season. If there is such a problem, then the fight against scab should be carried out together, only then can we hope for a positive result.
Preventive treatment is also carried out using those fertilizers that are commonly used for foliar dressings. If we consider these supplements as a medicine, then their concentration should be very high. If preventive irrigation is planned, the percentage of the drug dissolved in water should be low. For these purposes, they use means familiar to all gardeners: potassium salt (15%), ammonium nitrate (10%), potassium nitrate (15%), ammonium sulfate (10%). With the arrival of autumn, the crowns of the trees and the ground under them can be treated with urea dissolved in water (7%) or nitroammophoska (10%). Thus, the apple trees will be fed, and the pests and fungal spores will be destroyed (an overwhelming number of them).
Resistant varieties of apple to scab
To date, the efforts of breeders created more than 150 varieties of apple trees that have immunity against scab.
I will list some of them:
- Variety "Delight", has a sour-sweet fruit with pink flesh, skin color is red, with dark crimson stripes. Cold-resistant cultivar, characterized by high yield. The branches are prone to rapid growth, so “Uslada” needs frequent crown formation.
- Apples "Medunitsa", as is already clear from the name, have a honey taste, they are distinguished by good orezhkost (up to 2 months). It begins to bear fruit in the fourth year of life, gives a harvest by the end of the calendar summer. Crohn is also prone to sprawl, needs frequent pruning, shaping.
- The variety "Star" is resistant to cold and most fruit diseases
- The “Chudnoye” cultivar is distinguished by horizontal growth of branches (self-stiffening) and small size of the tree. The fruits have a pronounced yellow color, their weight can reach 200 g.
- Apple varieties "Moscow winter" grow to large sizes (very high), have a dense leafy crown. It is a frost-resistant cultivar whose fruits are characterized by high keeping quality (can be stored until April). The fruits ripen around the end of September.
- The variety "Orlinka" is distinguished by high yield and unpretentiousness. Skoroplodny sortovidov, fruits ripen around mid-August. Sleepiness is low.
Also, the following apple varieties are resistant to scab disease: Saffron Peppin, Golden Summer, Nocturne, Yekaterinodar, Dawn, Fairy, Red Amber, Talida, Fortuna, Juno, Vasilisa, Rodnichok, Orpheus, Soyuz, Margo, Lyubava, Scythian Gold "" Honey Gold "and others.
What is a scab
Any gardener at least once in his life had to deal with an apple scab, which is quite difficult to handle. Regardless of the region of growing trees, varieties of apple trees, weather conditions, plants sooner or later undergo this insidious fungal disease. Most often, the fungus can be seen on apples that grow in temperate regions. This is due to the fact that the scab loves rainy and wet weather, because these are the most favorable conditions for its development.
Consequences of infection can be irreparable, because the fungus affects not only apple trees, but also pear, cherry, apricot and other fruit trees, as well as bushes with berries. The disease leads to lower yields, and the plants become less resistant to frost.
As a preventive measure, it is advisable to use folk remedies or biologics, which are not toxic either to humans or to beneficial insects.