Why on the grapes a white raid and how to deal with it?

A good vineyard is the dream of any gardener. A neat vine and large fragrant bunches create a special atmosphere. And how nice to get yourself a dessert ready in the evening! However, the cultivation of grapes has its own difficulties, and primarily because the fruit vine is very beloved by pathogenic bacteria and viruses. Today we want to make out the reasons for the white coating on the grapes.

Achievements of modern agricultural technicians

Only at first glance, gorgeous bunches grow without any effort by the gardener. The most beautiful and delicious varieties are always amazed at first. Despite all the efforts of breeders, it is not possible to overcome this law. Only varieties with a mediocre taste have a certain resistance to the most formidable diseases, including mildew. But if such grapes, for example "Isabella" with sour blue berries, are crossed with a good sweet variety, then the resistance is markedly reduced, and you can again notice a white coating on the grapes.

Shocking variety

If you are determined to grow tasty berries on your site, then it will take a lot of attention. First of all, non-infectious diseases that are caused by heat or high humidity, poor soil or excess nutrients are dangerous for the vineyard. They are easy to avoid if you provide optimal conditions in your garden.

However, the list is not limited to this, there are hundreds of different infections. If you observe a white coating on the grapes, you will have to break your head, which is what it is. Infectious diseases spread through the vineyard very quickly. This leads to a significant loss of yield or death of the entire entire vine. Infection occurs through infected bushes, garden tools, as well as with wind and water. Imagine all the risks, and you will understand how important it is to constantly monitor the garden.

Downy mildew

Everywhere there are vineyards, sooner or later it will germinate mildew. Its pathogen is the fungus. He settles on living tissues and forms a white coating on grapes. Get rid of this uninvited guest is not easy, because he winters on the fallen leaves and in the ground, perfectly tolerates the cold and heat. Over a season, 20 generations of fungus can be replaced.

Outwardly, the disease manifests itself in the form of spots. In wet weather, a white coating appears on the leaves of the grapes. When it's hot and dry, there are no such symptoms. To combat this disease, it is necessary to perform preventive treatment. This will save your harvest and prevent a new outbreak.

Of the remedies, Antracol and Bordeaux mixture, Kuproksat, Thanos, and Khorul are the most effective drugs. The first treatment is performed when the young shoots reach 15-20 cm in length. The second is necessary before flowering, and the third - when the berry begins.

How to recognize mildew

At the initial stage of the disease, this is not easy. Usually people understand that the vine is infected when it becomes serious. You will be very lucky if the summer turns out to be rainy. In wet weather, you can see the fluff on the leaves and begin to act. But on hot days even an experienced gardener will not notice the approaching trouble. Completely get rid of mildew can only be when extracting all shrubs from the ground. In this case, fungal spores can wait for the appearance of a new vine for 20 years. Its growth can be restrained every year by special fungicides, not to miss preventive measures.

Genuine powdery mildew

This is a dangerous disease that causes a white coating on the grapes. In scientific terms, it is called oidium. Called the disease with the same name fungus. At the very beginning of the growth of grapes shoots, an attentive horticulturist can find among them such that are lagging behind in growth. Their leaves look curly, they are completely or partially covered with white dust. Since June, this plaque becomes noticeable on the lower and upper parts of the leaves. All the inflorescences and bunches look as if they were sprinkled with flour.

White plaque on the grapes in this case indicates that your vine soon awaits a big change. Fruits burst and collapse. Oidium causes great damage to gardening. The incubation period is very short, so you may not notice how the disease will cover the entire vineyard. Most often, the spread occurs in wet and warm weather, as well as in moderate humidity.

What awaits your vine

White coating on the leaves of grapes is just the beginning. Over time, the green mass darkens, then turns yellow and withers. However, the affected leaves do not fall off, but continue to hold firmly in their places. New shoots of the plant or a freshly planted vine immediately becomes infected. With the onset of the cold period, the plant completely dies in 3-4 weeks.

If the growth of the vine stopped, and you can already find black spots on it, then you can be sure that the plant is slowly going to ruin. Why the white raid on the grapes is already clear. It is destroyed by the fungus. However, even if the infection occurred at the end of the summer, there is not much good. Half of the crop will turn white and dry. To hope for the second part is also not necessary. The remaining berries become soft, have putrefactive taste. Winter, too, will not bring you salvation. The fungus will transfer the cold perfectly and finish the next year.

Treatment of oidium

If the grapes are covered with white coating, you need to take immediate action. This treatment with special antifungal drugs, such as "Topaz" and "Strobi", "Horus", "Tivov", "Thanos". For treatment, it will be necessary to repeat the spraying after ten days. However, this disease is much easier to prevent than treat. Agrotechnical techniques are reduced to the ventilation of bushes by tying shoots and pasynkovaniya, as well as control of weeds. Observe the timing of preventive treatment indicated for mildew treatment.

Alternaria

This is another fungal disease that is gaining popularity in recent years. It is widespread almost everywhere. The hotter and rainy the weather, the more likely its appearance in your vineyard. Affects leaves, shoots and berries. Outwardly very similar to oidium. Already 10-14 days after infection on the leaves appear silvery spots, and then mold. The berries are formed by a film and velvety sputtering.

White coating on the bunches of grapes in this case says exactly about one thing - the crop is ruined, but you need to try to save the vine itself. If the infection was at the end of the season, and because of too hot weather, its development did not happen, then the fungus will begin to grow after harvesting and spoil it all very quickly. To determine if the vine is infected, it is enough to take a part of the shoot that seemed suspicious to you, and place it in a moist environment. This will be enough to cover the material with a velvety coating.

Methods of struggle

Protecting the vineyard from an alternative is not too difficult, but all activities must be carried out regularly. Of the biopreparations, the treatment with "Trichodermine" gives good results. To prevent the causative agent from hibernating in the vineyard, in autumn it is very important to clean up your site and carefully burn all dry plants. Symptoms of this disease manifest themselves brightly most often in the second half of the vegetation, but one can not wait for them. Protective measures need to start in the spring.

For this very well suited "Bordeaux mixture" or special fungicides that contain mancozeb. An example is the preparation "Ridomil". Starting with the period of the formation of bunches, one should use systemic fungicides, examples are "Skor", "Quadrice" and "Rapid Gold". The interval between treatments is 10-14 days.

On the grapes white coating: what to do

The symptoms of these diseases are quite similar, so it can be difficult to distinguish one from another. In order not to lose valuable time, you need to start processing immediately. Therefore, if you notice a characteristic symptom, first of all prepare a solution of potassium permanganate. Add only a few crystals to the water to make it pink. It is very important that every leaf is moistened. Carry out this treatment in the spring when your vine just wakes up. Even if the plant is not infected, it will be an excellent prevention.

When there is already a white coating on the leaves of the grapes, what to do in this case? Get in the specialized store several complex fungicides and use the instructions. By alternating between them, you will not give the fungus a chance to adapt.

Emergency help

But what about in cases of severe damage to the vine? Let's see what to do if you missed the moment, and already on the grapes a white raid. How to handle the vine in this case? Colloidal sulfur will help you . Not a bucket of water will require 10 g of active ingredient. Spraying can be performed every week before the flowering period of the grapes.

If the bush starts to turn black, then audit your plantings. The most affected plants must be removed and burned, the rest - carefully processed. About the berries are not talking, it is important to save the bushes themselves. Moreover, even if by the end of the season you have successfully treated, clusters are recommended to burn so that they do not become a source of controversy. From the spring it will be possible to conduct preventive treatment and wait for a new crop.

Prevention

Having a certain experience and knowledge, the gardener necessarily uses modern methods on his site to avoid unpleasant consequences. Beginners are somewhat more difficult, but they must also learn to protect their garden. Especially this applies to those who grow varietal grapes. The disease can affect even the most well-kept garden and spread over it with the speed of lightning.

In the beginning of spring, always spray the vine with antifungal solutions. Late in autumn, before folding the plant for hibernation, this procedure is repeated. But the treatment with chemicals is not all. Pay special attention to the soil. Grapes draw from it a huge number of nutritional elements. If it is not fertilized, the vine will be prone to fungal diseases. It is advisable to use special mixtures for dressing, which are sold in stores. Perfectly suitable complexes that contain potassium, phosphorus, magnesium and other minerals.

It is very important to monitor the condition of the vine. The vineyard must be constantly wet, light and airy. Therefore, the shrub should be pruned and tied up in time, and the stepchildren should be removed. A well-groomed vine is easier to inspect, and compliance with all these parameters is a kind of guarantee that the disease will bypass it.

Cultivation of a vineyard is a troublesome, but very grateful occupation. A well-groomed shrub will thank you for the time spent by sweet berries, which can be eaten directly in food or harvested for the winter.