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Apple trees infected with a marsupial fungus called Venturia unequal, are covered with yellowish-green spots, which gradually turn brown or black. Infected leaves crack and fall early, and the fruits shrivel, deform and develop poorly. The disease, known as scab, destroys the immunity of the tree and reduces yields. It is not easy to cure apple trees, but it is possible if you regularly take care of and treat with special means.
Traditional methods
The range of fungicides is rich and diverse, but not all gardeners agree to spray fruit trees with chemical preparations. Natural remedies are safer, but are intended for the treatment of apple trees that are sick with scab for the first year. If you properly treat plants with such compounds and take preventive measures, it is highly likely that the fungus will die. Folk recipes failed? Have to buy fungicides.
Horsetail, mustard and manganese
Leaves recently bloomed and covered with pale spots? It is recommended to pick three buckets of field horsetail and pour over settled water. Cover with a sheet of iron or a lid, set aside in a corridor or under a shed. After 3 days, separate the liquid from the meal and spray the apple from the tops to the roots.
The fungus will also destroy mustard powder, which is used 4–5 times per season. Apple trees are treated with a sharp solution after:
- the appearance of the first leaves;
- bud formations;
- falling petals when the flowers turn into the ovary;
- before ripening fruit.
Dissolve 80–90 g of greenish powder in a bucket of settled warm water. Stir so that the mustard is completely dissolved, and plenty of spray the crown and tree trunk. If the bitter solution gets on green apples, do not worry. The powder does not affect the taste of the fruit.
Potassium permanganate copes with bacteria and fungus, so infected apple trees are sprayed with a concentrated dark pink solution. To process plants 3 times, it is possible and during fruit ripening. Abundantly irrigate the branches and roots, seize even healthy trees for prevention.The bark after potassium permanganate is covered with brownish stains, but they are harmless.
Salt, Serum and Fire
In spring, the plants are sprayed with concentrated brine. The tool slows the growing season, the leaves and buds appear later than usual, so the scab does not have time to settle on the branches and buds. In a bucket, they dilute the packaging of table salt, mix it thoroughly and water bare trees.
The branches covered with young leaves and buds will save whey from the fungus. You will need a natural product that is passed through a filter, poured into a spray bottle and carefully applied to the bark and green shoots. Milk-borne bacteria contained in the serum “eat” the fungus, delicately cleansing the plants from stains.
Chemical attack
Natural remedies for scab work slowly, and the disease spreads quickly. The fungus affects not only apple trees, but other fruit trees as well as shrubs. The fungicides will stop the disease.
Autumn work
Chemical preparations are recommended to be used in the fall, when the fruits are collected, and the damaged leaves have fallen. The tree has time to clear itself of synthetic substances and recover from the fight with scab.
Branches covered with black or brown spots are cut off, like bark. The open areas are smeared with blue vitriol. 30 g of substance are dissolved in a liter of filtered liquid. Apple trees are sprayed from a spray bottle.
It is recommended to dig up the ground under the trees, but if, instead of the usual soil, the garden is decorated with a lawn, then the grass is not pulled out, but disinfected with ammonium nitrate. Prepare a 10% solution, which is generously watered area under the trees.
It is not necessary to remove fallen leaves, because they protect the root system from frost. It is enough to destroy the scab, which remained on the raw material, urea. It will take 700 g of the substance and a ten-liter bucket of filtered water. Spray the solution or pour the leaves and the ground around the apple trees, as well as process the trunks.You can take a brush and soak the trees with urea so that the product gets onto the fungal spores that are hidden under the bark.
Alternative - solution of ammonium nitrate. On a bucket of distilled liquid 1 kg of the chemical. Use as urea.
Spring treatments
Gardeners are advised not to hope that one or two autumn disinfection completely destroy the fungus. It is better to be safe and in the spring, before the appearance of buds, spray healthy and affected apples with a 3% Bordeaux mixture. The procedure is repeated after the separation of the buds, when they first begin to divide into groups and bloom. Reduce the concentration of the solution to 1–2%.
Disinfection with a weak Bordeaux mixture is carried out three more times per season:
- when the last buds wither;
- 2 weeks after the second disinfection;
- after 21 days, during the formation of the fruit.
Irrigating apples Bordeaux mixture is recommended after heavy and prolonged rains, which wash off the remnants of the funds. The product is applied to slightly wet or dry branches 2–3 weeks before the crop ripens. If it rains just before picking, it’s best to wait until autumn.
The fungus is too active, and the apples poured and almost ripe? Instead of Bordeaux mixture, softer fungicides are used, like:
- Raek;
- Chorus;
- Soon;
- Fitosporin-M
The last remedy belongs to the group of biologics, which are not as aggressive as chemical analogues, but it is impossible to misuse synthetic solutions.
Launched apple trees that have been sick with fungus for many years will save:
- Extrasol;
- Zircon;
- GUMI pasta.
Sick plants are irrigated with medicinal solutions in the spring: when the buds with leaves begin to open, and when the ovary becomes the size of a walnut. For the processing of a five-year apple tree, 40-50 liters of money will be needed, and for older trees, it is recommended to prepare from 100 to 200 liters.
Residents of rainy regions are advised to Kuproksat, which is resistant to precipitation. A bucket of liquid will need 25 g of fungicide. Use twice per season.
In the spring, when the temperature rises above +14, and the weather will be sunny, without a hint of thunderstorms, apple trees are treated with Vectra solution: 3 ml of the drug per ten-liter bucket.
Strobi fungicide is considered one of the most powerful and effective.It destroys the fungus at a temperature of +4 to +1 degrees and is not afraid of moisture. Enough 1 g of fungicide in 10-12 liters of distilled water. Between treatments take a break of 2-3 weeks. You can use other, softer tools or solutions from natural ingredients. Trees, for the treatment of which Strobe was used, must rest for at least 1 year. If a scab appears on them again, they recommend the Bordeaux mixture or its analogues: Kuproksat, copper oxychloride
A fungus that actively reproduces and spreads throughout the apple tree will destroy the fungicide Bi-58 New or Horus. Topaz scab will stop, and the soft Cumulus preparation, based on colloidal sulfur, is allowed to be used 2 weeks before harvest.
Preventive measures
Infected apple trees that could not be cured with natural means and fungicides are recommended to be cut down and burned.Leaves that have fallen from young trees that are no longer than 4–6 years old are transferred to a compost pit, covered with a thick layer of manure, or dug up along with the ground. Such apple trees are too fragile and defenseless, therefore they recommend not to risk and cover the root system with sawdust or straw.
In winter, plants that have suffered spring and autumn treatment with fungicides, necessarily fertilize. Suitable potassium salt or nitrate, potassium sulphate or ammonium.
Scab is an insidious disease that is resistant to natural and synthetic drugs, so the fight against it begins with the first symptoms. Fungicides inhibit marsupial fungus for some time, but if you do not take care of the apple trees and do not fertilize them, the infection returns and begins to attack other fruit trees.
Video: scab control on apple trees
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