Alternariosis of grapes: symptoms and treatment, prevention and resistant varieties

Pathogenic microbes often infect plants in the garden. Diseases have different origins. The cause of Alternariosis of grapes are saprophytes - fungal microorganisms. In recent years, abnormal heat has led to the spread of the problem in many regions of the country. Therefore, it is important for gardeners to know the symptoms of the appearance and methods of dealing with parasites.

Description of the disease

The breeding ground for fungal mold is high air temperature combined with high humidity. Such conditions often occur in regions traditionally suitable for growing grapes.

The causative agent of the disease is dangerous, first of all, to weakened plants. Fungal spores quickly spread over the ground part of the vine and cause leaf and fruit necrosis.

If you do not start treatment at the first signs of the disease, the horticultural crop may die within 5 days. Alternariosis is dangerous for berries both during ripening and during storage of the crop.

How the signs of Alternariosis of grapes appear

Symptoms of damage to grapes by pathogenic microbes appear already in the spring. May thunderstorms and air temperatures above 26 ° C create favorable conditions for spore infestation. The vine and leaves are covered with a silvery coating and yellowish spots. As the disease progresses, light blotches darken and then turn black. Shoots gradually dry up.

In summer, Alternaria also affects grapes. The berries will shrivel, become gray and lose their taste.

Signs of illness beginner growers are often confused with traces of oidium. To make sure the diagnosis is correct, the shoots are placed in a humid environment. Fungal plaque quickly covers the entire branch of the plant.

Methods of treating the disease

Alternariosis treatment is started immediately to prevent crop loss and death of the grape bush.

Chemicals

To combat fungal diseases, copper-containing preparations are chosen. Plant Treatment Steps:

1. Slaked lime is diluted in a separate container and filtered.
2. Filter the copper sulfate solution.
3. Combine the resulting mixtures.

Vine growers also use other chemicals for spraying. It is recommended to treat a diseased culture according to the following scheme:

Before fruit ripening (every 2 weeks, starting from the last days of May)Use one of the preparations: "Rapid", "Quadris" or "Cabrio-top", as well as "Skor »

Processing times	Means used
During the period of swelling of the kidneys after tying the shoots (from March 20 to April 10)	Prevention with copper-containing fungicides
After the leaves appear (April 25 to May 10)	Trichoderminus

Spraying times vary depending on weather conditions. And the procedure must be repeated if it rained immediately after processing the grapes.

Folk remedies and recipes

At an early stage of the disease, folk methods are also effective for the treatment of Alternaria.

Mullein Infusion

To prepare the mixture, you need to pour about 3 kilograms of manure with a bucket of water. The resulting composition is left to infuse. After 3 days, the solution is filtered and then the vine is processed.

Manure for spraying is not used fresh, but after a short pause to avoid burning the leaves. A folk remedy for alternariosis is also popular in small private vineyards, and even in large farms engaged in mass cultivation of culture.

Potassium permanganate solution

The product is obtained by diluting 5 grams of potassium permanganate in 11 liters of water. Agronomists advise observing the dosage so as not to burn the surface of the leaves. During preparation, they are guided by the color of the solution.The required concentration gives the liquid a faint pink hue.

Potassium permanganate is sprayed with a bush of grapes completely, and not just the affected shoots. Early shoots are watered under the root.

Milk liquid

Sometimes a mixture of milk and water is used to combat Alternaria. The proportions for preparing the solution are 1 to 10. The composition is poured into the sprayer 30 minutes after stirring. Process the ground part of the vine. Heat activates the development of bacteria, which displaces fungal spores.

The effectiveness of the method is not very high. This method of processing is used for early detection of the disease.

Laundry soap with soda ash

Ordinary laundry soap also copes with Alternariosis of grapes. To treat the fungus, stir 30 grams of the product in a bucket of water and add the same amount of soda ash.The mixture forms a film on the leaves that inhibits the spread of spores. And the alkaline environment destroys pathogenic bacteria. Spraying is useful to repeat after 10 days.

Infection prevention

Prevention of Alternariosis of grapes provides for a comprehensive implementation of activities:

1. Mechanical ways to prevent the disease are regular pruning of infected shoots, followed by burning.
2. Agronomic methods refer to the use of fertilizers and concentrates with microorganisms. Useful substances will strengthen the plant's immunity and prevent harmful bacteria from developing.
3. Prophylaxis of chemical orientation involves the treatment of the vine with preparations with copper. Experienced growers alternate blue vitriol with a 2% solution of Bordeaux mixture.

As additional measures, the introduction of mineral complexes, timely watering and loosening of the soil are used. Removal of weeds from the site will favorably affect the development and maturation of grapes.

Resistant varieties

Some varieties of grapes have strong immunity to diseases. Alternariosis rarely affects such plants. Gardeners advise growing Rkatsiteli or Traminera. Resistant to pathogenic microbes Cabernet Sauvignon and Riesling. Amur varieties have proven themselves well - Triumph, Breakthrough. No problem Marinowski or Amethyst grapes.

Preventive measures help avoid crop problems. At the first suspicion of alternariosis, treatment of the plant should be started immediately. A neglected disease will make it impossible to harvest a good harvest of he althy and tasty berries.

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