Grapes, like other cultivated plants, can have various diseases. They infect leaves, inflorescences, thereby harming the plant. Oidium (another name is powdery mildew) is one such common disease. In this article we will discuss the oidium on grapes: consider the treatment of this disease, as well as discuss the best way to handle the plant.
Description of the disease
Oidium is a fungal disease.affecting shoots and leaves. If conditions are favorable, then it goes to the inflorescences and does not allow them to fully develop and ripen.
Powdery mildew does not spread on dried shoots and leaves, but lives only on living tissues. In the form of mycelium, oidium is located in the cracks of the bark, on the kidneys and winters there. 
The spores of this disease persist on the leaves and shoots all season. It multiplies very quickly, forming new spores, and spreads throughout the bush, and then moves to neighboring plants.
In regions where spring is early and warm, powdery mildew is activated very early and affects newly grown young shoots. In colder climates, this disease wakes up when leaves appear on a bush.
Important! Berries affected by oidium are not suitable for consumption, even as a raw material for wine.
Causative agent
The causative agent of oidium is a fungus of the genus Uncinula. This parasite develops on the surface of grapes. 
A gray-white patina on the plant is formed using extremely thin hyphae attached to the plant's surface by suckers called appressoria. To absorb food, this mushroom implants its haustories into the epidermis. The affected cells die, forming a dark brown mosaic.
With the help of wind, conidia of the fungus are transferred to areas of grapes that are not yet infected. The best conditions for the development of this disease are dampness and humidity above 80%, as well as poor ventilation of the site.
Find out what fungicides to use in the vineyard to protect your crop.Oidium incubation period is 7-14 days, depending on air temperature. Conidia develop best at +20 ° C, but their growth can begin at +5 ° C.
Signs of infection
Mealy dew of grapes appears on all of its above-ground parts:
- a gray-white scurf appears on the leaves, which spreads to both sides of the leaf;
- leaves are bent at the edges, curled, turn yellow;
- plaque appears on clusters, flowers, as if they were sprinkled with flour;
- dark spots are formed on the shoots;
- tissues of the shoots turn black and die off in some places.
- infected inflorescences die off;
- grapes affected by the disease, dry up before;
- small fruits crack and dry, the seeds are exposed.
Control measures
To get rid of oidium on grapes, you need to take the necessary measures to combat the disease.
Prevention
To avoid the appearance of powdery mildew, you need to carry out prevention. Good care will help reduce the chance of powdery mildew to a minimum. 
In autumn and spring it is useful to dig the ground under the grapes. It is also good to feed the bushes with potash-phosphate fertilizers.
To protect the grapes, they are treated with fungicides. Many people prefer the tool "Tiovit Jet." If the grape variety is susceptible, it is better to use Topaz.
Important! Doses of drugs used for prophylaxis should be 2 times less than therapeutic ones.Useful tips to help avoid disease:
- The soil under the grapes must be kept clean, dry leaves and branches clean in time.
- Tools should be disinfected after trimming.
- The plant should not overfeed. It is best to use balanced blends.
- When watering, it is undesirable to allow water to enter the part of the bush that is above the ground.
- Avoid thickening landings.
Biological methods
The biological method of struggle consists in preparation in the spring of saprophytic microflora from humus.
This is done like this.:
- In the 100-liter barrel pour humus, so that he took her third part.
- Fill with water heated to +25 ° C.
- Cover with sacking and, regularly stirring, wait 6 days.
It is necessary to spray such microflora twice a season, observing an interval of one week. If the disease has spread much, you need to spray it even after flowering.Did you know? For the preparation of one bottle of wine you need about 600 grapes.
Potassium permanganate
During the ripening of berries, it is better not to use chemicals. Therefore, a solution of potassium permanganate (5 g per 10 liters of water) will help to stop the disease for a while.
It will be useful for you to learn how to protect your crop from diseases and pests in autumn.
Sulfur-containing drugs
Sulfur is fatal to the parasite. The fungus absorbs it and dies. From the oidium on the grapes for the treatment dissolve 100 g of sulfur in water (10 l), and for the prevention - 40 g. 
This is best done in the morning or in the evening, as in the heat of sulfur burns leaves and fruits. This method works at temperatures above +18 ° C. If the temperature is lower, you can use sulfur-containing drugs, such as "CabrioTop."
Drugs from oidium
After flowering, use such drugs from oidium on grapes: "Skor", "Rubigan", "Topaz", "Bayleton". There is also "Fundazol", but it is effective only for young seedlings. From last year's oidium "Horus" or "Strobe" helps best. These drugs are used in cold weather.
Familiarize yourself with the rules of planting and pruning grapes in spring.
Folk remedies
There are also popular methods to combat the disease.:
- 3 tbsp. l soda mix with 4 liters of water and add 1 tbsp. l liquid soap. Spray grapes immediately.
- Stir 1 kg of sifted ash in warm water (10 l). Need to insist 5 days, stirring occasionally. Before processing, add grated soap (30 g).
- 2 tbsp. l dry mustard diluted in 10 liters of boiling water. After cooling with this mixture, water and spray the grapes.
- 25 g garlic cloves chop and dilute with 1 liter of water. A day to put on the grapes.
- Korovyak need to fill with water 1: 3. After 72 hours, swill strain and dilute with water 3 times.
Resistant varieties
There are grape varieties resistant to fungal diseases. These are Aligote, Rkatsiteli, Kishmish, Merlot, Sauvignon.
Did you know? There are more than 10 thousand grape varieties in the world. This is more than any other culture.
Oidium - a malignant fungus, quickly spreading over all above-ground parts of grapes. If measures are taken in a timely manner, the risk of disease can be significantly reduced.
