Oidium on grapes: how to deal with powdery mildew and how to process

Almost every year, gardeners are faced with oidium on grapes, due to which its yield deteriorates several times. This disease is considered one of the most common pathologies that appear on grape bushes. To save the plant, you should familiarize yourself with the description of the disease and methods for its elimination in advance.

Description of disease

Infectious diseases of the fungal type often affect grape fruits. Because of this, they cannot be further processed and consumed fresh. Among common infections, powdery mildew or oidium should be distinguished.

The disease oidium plants become infected after exposure to pathogens that live in the vine. In spring, when the air temperature warms up to 15-20 degrees, the fungus begins to actively develop and infect the nearest vineyards. Most often, bushes become infected in the second half of spring or early summer with high humidity. However, with daily rains, the humidity level reaches too high, which leads to a slowdown in the development of the disease.

It is difficult to determine the presence of oidium at the initial stage of its development, since it practically does not manifest itself in any way. Only after 5-6 days you can notice the first symptoms of pathology. First, it affects the lower leaves of grape bushes and gradually spreads to the upper leaves and fruit clusters.

Causes of occurrence

It is recommended to study the main causes of powdery mildew infection in advance. This will help to understand why grape bushes can become infected with such a dangerous disease.

The causative agents of oidium are quite often found in the upper layers of the soil. However, they need optimal conditions for their development. For example, if the weather is sunny, warm outside, and a person complies with all agrotechnical rules for growing, then the fungus will not develop.

There are a number of conditions that contribute to the infection of vines and the further development of the disease. These include:

Regular cloudy weather with increased air humidity. Lack of sunlight and high humidity levels are very dangerous for grapes. It is under such conditions that the causative agents of most fungal infections are activated.
Increased level of nitrogen in the soil. Some summer residents, when growing grape bushes, add too much nitrogen fertilizer to the soil, which contributes to the development of powdery mildew.
Dense plantings. Shrubs that are planted too close together are prone to infection with oidium.
Wrong watering. Sometimes plants are watered very often, because of which the soil does not have time to dry completely. This significantly worsens the protective functions of grapes, which leads to infection with fungal diseases.

Signs of infection

In order to timely identify oidium on a plant, you should familiarize yourself with the main signs of the onset of pathology. There are a number of symptoms that appear only with this disease.

The first signs of oidium disease appear as small white spots that appear on the surface of the lower leaves. After 1-2 days, the size of the spotting increases, due to which the leaves are completely covered with white bloom. With the further development of the pathology, the spots progress, become denser and almost completely cover the grape seedlings.Because of this, when externally examined, infected plants seem to be completely covered with cobwebs or sprayed with lime liquid.

However, in fact, the surface of leaves, fruits and stems is covered with fungal epithelium, which consists of many conidia.

If the grapes are not cured in time, its leaves will begin to become covered with yellow spots and dry out. Also, due to the disease, the growth of bushes slows down and their immune system weakens. Because of this, the grapes cope much worse with temperature changes and even minor frosts.

How to deal with oidium on grapes?

It is necessary to deal with the fight against the disease when its first symptoms appear. This will stop the further development of the pathology and prevent the grapes from dying.

Any control measures are aimed at the complete destruction of the pathogens of the fungal infection.There are various methods of dealing with oidium that will help cure the bushes. To increase the effectiveness of each of them, you will have to do complex treatment. However, before that, you will have to familiarize yourself with the main ways to fight against a fungal disease:

Sulfur solution. Experts advise doing powdery mildew treatment using sulfur liquid. The procedure is best done in the morning or evening, when there is no bright sunlight. When spraying the liquid, make sure that it gets on all the affected areas of the grapes.
Solution of colloidal sulfur. Treatment with such a remedy is considered quite effective, as it helps to quickly get rid of fungi on the bushes. Experienced gardeners recommend spraying once a week.

Effective chemicals

There are several effective chemicals that can help cure infected grapes. However, before using the drug to combat oidium, you will have to familiarize yourself with each of them in more detail:

"Topaz". Among gardeners and lovers of growing grape bushes, the Topaz tool is popular. The drug effectively fights many fungal infections, and powdery mildew is no exception. To get rid of the symptoms of pathology and save the plant, you will have to spray at least three times a month.
Vitaros. For the prevention and elimination of signs of powdery mildew, you can use Vitaros. This fungicidal preparation should be used in early spring, when pathogens are just starting to become active.
"Quick". To quickly eliminate the symptoms of infection, you should use a solution from "Skor". When preparing it, a glass of the drug is mixed with 10-12 liters of water. Plants are treated at least twice a month.

Folk recipes

Also, folk remedies are used to eliminate oidium. The most effective include the following:

Serum. Fans of folk remedies often use whey, which can save grapes from infectious diseases. Such a solution is not only able to eliminate the signs of the disease, but also improve the functioning of the immune system. To create a solution with your own hands, you will have to stir a part of the serum with two parts of heated water. The mixture is processed every two weeks for three months.
Iodine. A solution prepared from medical iodine also effectively fights oidium. When creating a spray mixture, 10 ml of iodine is added to a container with ten liters of water and mixed thoroughly. Then, using a spray bottle, grape brushes and leaves, which are covered with a white coating, are sprayed with liquid. The procedure is carried out twice a week.
Ash. An ash remedy can prevent the death of plants infected with powdery mildew. To prepare a medicinal liquid, a kilogram of sifted ash is mixed in 7-8 liters of water and infused for 20-30 minutes.After that, 200 grams of soap is added to the solution. Infected grapes are sprayed with the solution three times a month.

Prevention measures

Growing grapes, they must be engaged in the prevention of diseases, since by taking preventive measures on time, you can protect plants from death. Experienced gardeners consider proper care of the grown plant to be the best prevention. By observing all the agrotechnical rules of cultivation, the likelihood of becoming infected with oidium is minimized.

In order for the grape bushes not to get sick with anything, you will have to properly irrigate. Moisturize the soil should be no more than twice a week. At the same time, the bushes should not be heavily flooded, as this will increase the humidity of the soil and air. During prolonged droughts, watering becomes more frequent, as the soil dries out faster in such conditions.

Also, grapes need regular feeding, which will increase its protective functions. In summer, the soil is fed with potash fertilizers at least three times.

Most resistant varieties

Some gardeners are growing oidium-resistant grape varieties. These include:

Aligote. This variety is popular among winemakers, as it belongs to the wine varieties of grapes. In open ground, it is grown only in the southern or central regions. In cold climates, it is better to grow in greenhouses so that the yield is higher. The advantages of Aligote include not only its resistance to powdery mildew, but also the taste of the crop.
Sauvignon. A common variety that many grow to make aromatic white wine. The distinctive features of Sauvignon include small grape clusters with small berries, as well as resistance to many common diseases.
Savraska. A well-known Altai variety with early crop maturation. It features huge brushes, the length of which reaches 35 cm, and delicious berries.

Conclusion

Powdery mildew is a common disease that affects many grape varieties. To get rid of it and protect the planted grape bushes, you will have to familiarize yourself with the main ways to deal with oidium and preventive measures.