Grey rot on grapes: how and when to process, what to do and how to fight

Grapes are a tasty and he althy berry. A real storehouse of vitamins. To collect a high yield, it is necessary to protect the grapes from gray and other rot on it; you need to know how and when to process the vine. When infected with a fungus, whole clusters suffer. Even young shoots and leaves. The task of the grower is to prevent diseases or effectively deal with ailments that have appeared on the plant.

What are the varieties of rot?

There are several varieties of rot. The most common are gray, white, black rot.

Grey rot on grapes is more common than other species. It can affect different parts of the plant. The fungus adversely affects the crop. Infected berries are not suitable for food and processing. If the disease is not stopped in time, it can affect the entire vineyard.

No less dangerous is the appearance of white rot on grapes. If the fungus is not detected in time, it will destroy most of the crop. Another danger lies in the possibility of damage to other cultivated and wild plants.

Black rot that appears on grapes differs from others in that it overwinters on the vine. After the start of shoot growth, the plant becomes infected. This happens in late spring or early summer when it is warm and humid. Near water bodies, this process is faster.

Reasons for appearance

The causes of rot infection are different. Why do grapes rot? To a greater extent, this is influenced by weather conditions. Long rains favor the appearance of gray and black rot. White occurs after long dry days.

The whole plant is affected by gray rot. But it is especially dangerous for ripe berries. With an excess of moisture, the skin bursts, the fungus multiplies rapidly in favorable conditions. The same result occurs after the fall of hail, which injures the delicate skin of the berries. Wasps and garden pests cause damage.

When berries are affected by black rot, part of the crop dies. Shoots and leaves are not at such risk.

In the spring, the white rot fungus awakens, overwintering in the bark and fallen leaves, which infects the shoots. Sunburn is another reason for the rapid spread of the disease. From the affected berries not harvested in time, he althy fruits become infected.

Signs of disease

Signs of diseases of different types of rot differ from each other.

When affected by gray rot, the leaves first become covered with brownish spots with a gray coating. Then they dry up. When the disease occurs during the flowering period, the inflorescences dry before they grow. If the clusters have had time to form, then during the defeat of this fungus, dark spots appear on the grapes, eventually turning into brown.

A sign of white rot is a white coating of mold covering the affected berries. Their size is decreasing. Leaves become infected, which darken and dry out. Less commonly, spots appear on shoots.

With black rot, the berries darken, lose their elasticity, wither, shrivel and rot or dry out. This fungus first appears on leaves as small brownish spots with dark edges.

Detrimental effect on grapes

The environment has a detrimental or beneficial effect on the yield and quality of fruits. Only under optimal climatic conditions is high quality grapes possible. It depends on the growth conditions of the plant from planting to harvest.

The volume of the crop is affected by the moisture content in the soil, the number of sunny days. Drought, rainfall intensity, hail and early frosts can serve as a threat to the growth of seedlings.

During prolonged rains it becomes cooler, the clusters do not ripen well. In berries, insufficient sugar content, excess acid. As a result, their quality suffers. With too much water, the grapes burst, providing the soil for fungal diseases.

With prolonged drought, the growth and ripening of berries is delayed, metabolic processes are disturbed, moisture evaporates faster, the pulp loses its juiciness. This leads to the death of more than one brush.

When the air temperature is high, sunburn can occur, affecting not only the leaves, but also the berries. Damaged leaves are covered with bloom and brown spots.Then they dry up and fall off. This opens other parts of the vineyard, which also deteriorate. The burn appears more often after watering, when water drops remain on the surface, which play the role of a natural lens.

To protect plants from sunburn, when watering during a hot period, it is necessary to avoid getting water on the leaves and berries. In the very sun - cover the bushes with a soft cloth.

Frosts also have a bad effect on the harvest. Even after a slight frost, the vineyard does not look the best. The intake of sugar in the berries is limited, they do not ripen. When the frost intensifies, the berries fall off. The leaves are disappearing.

Vineyards need good light to be productive. With a lack of light, the leaves become smaller, the shoots become thinner. The development of inflorescences slows down. Clusters are formed worse, fruit buds are poorly laid.The flowers fall off, the yield drops sharply. Vineyards growing on slopes and uplands are better illuminated.

With proper care of the vineyard, the volume of the crop and its quality increase. Not the last role is played by proper planting, tillage, bush formation, pruning, pinching.

If the vines are not tied up, they will come into contact with the ground, polluting the bunches. At the same time, the berry rots and cracks, becomes infected with mold, and disappears.

Most vulnerable varieties

Not all grape varieties are susceptible to rot, but there are shrubs that are especially sensitive to this disease.

Gray rot is more likely to affect those grape varieties that have a dense bunch and a high degree of sugar content. For example, such varieties of early ripening grapes as: Golubok, Zhemchug Saba, Rusbol, Muscat Tairovsky.

White rot suffer more often: Rhine Riesling, Seibel 1, Plavai, Alimshak.

Black rot affected varieties: Italy, Muscat Hungarian, Chassela white, Zhemchug Saba.

Ways and tips for treating rot

The main thing is to detect signs of infection in the early stages. This will help get rid of the disease and save most of the crop.

The following control measures should be taken to treat white rot on grapes.

Before treatment with antifungal drugs, the bush must be freed from infected parts. If there are two or three berries damaged by rot on the bunch, you need to remove the entire bunch of grapes. There is a high probability of infection spreading to other fruits.

Bordeaux liquid is suitable for processing a vineyard. Spraying should be done in the early morning or evening. Preparations containing theophanate methyl or penconazole are considered an effective remedy for getting rid of shrubs from rot.

You can spray grapes from gray rot with such preparations: Smilix, Switch, Ronilan. Processing is carried out four times per season. Also, treatment can be carried out with the help of copper sulfate. In ten liters of water, 15 grams of the drug is diluted.

What to do if the vineyard is affected by black rot? First of all, you need to remove the damaged parts of the bush. Then treat the grapes with special preparations, such as: Antrakol, Topaz, Bayleton. The first spraying is carried out after the leaves bloom, then - before flowering, the third time - during the growth of berries.

Final spraying is carried out in autumn, after harvest. If after the treatment of the grapes with drugs it rained, it is necessary to repeat the spraying again.

Ways to fight and protect grapes from rot are preventive spraying of shrubs once a month. Favorable conditions for the development of grapes will also play an important role. As you know, it is easier to prevent a disease than to cure it.

Folk methods of struggle

Many summer residents are wary of processing grapes with chemicals. They ask themselves: how to deal with fungus with folk remedies? There are several effective solutions that will help in the fight against rot:

50 grams of mustard powder dissolved in 5 liters of hot water. Insist in a dark place for two days. Ready mustard solution, before spraying, dilute with water 1:1.
Add ten drops of iodine to a bucket of water, stir. Treat the vineyard with the solution once a week.
In ten liters of water it is necessary to dilute 70 grams of soda. With the resulting solution, spray the fruits and leaves of grapes with a slight infection.
One hundred gram bar of laundry soap diluted in ten liters of water. Spray grapes with soapy water in cloudy but not rainy weather.
Dissolve 50 grams of soda ash in a bucket of water, pour in 40 grams of oil. Treat the bushes with this solution once every ten days.
In five liters of water, dilute a liter of kefir or sour milk, add twenty drops of iodine. Spray once a decade.
100 grams of dried horsetail pour a bucket of water, insist in a dark place for a day. Then boil for two hours on low heat. Strain the finished broth. After cooling, dilute with water 1:5. The decoction is stored for seven days in a cool place.

But do not forget that folk remedies can be used with a mild form of infection, or as a prevention of the disease. In severe infestations, fungicides should be applied.

Prevention measures

Before growing grapes, it is necessary to choose a suitable variety, in accordance with the climatic conditions of its further growth. To protect and prevent diseases, you need to create normal conditions for the growth and development of the grape bush:

First of all, it is sufficient lighting.
Timely pruning of the vine.
Properly selected fertilizer.
Shrub is not recommended to add organic fertilizer.
Produce all bait according to schedule.
Keep the soil under the bush clean, preventing leaves and fallen berries from rotting.
Moderate watering, loosening the soil, good ventilation of the clusters, constant inspection and spraying of the plant.

Prophylactic can be used at a time when the shoots reach fifteen centimeters, and in the fall, after harvest. The shrub must be treated with copper-containing preparations or potassium iodide.