Mildew on grapes.

What is Mildew?

This is a disease, namely a fungus that spreads at a breakneck speed throughout the grapes. Mildew is the most common disease in wild and domestic grapes. This is a kind of powdery mildew or in another way peronospora. For example, if cucumbers are ill with this, then you do not need to worry about grapes, since this disease is different for each plant and will not be transmitted from that same cucumber to grapes.

Briefly about grapes.
Grapes are a berry crop from the grape family. When cultivating this plant, care must be timely, high-quality and delicate.

Briefly about mildew.
Mildew is a very dangerous and harmful disease that can cause serious damage to grapes. However, there are a bunch of ways to solve this problem.

Previously, this disease did not exist. It’s true, Mildew hadn’t existed before and everyone was growing grapes and didn’t know grief. This disease was brought to us from Africa in the nineteenth century. First she came to Europe, after a couple of years she came to us in Russia. Further, this disease spread throughout the world and only in America a couple of grape varieties were able to develop immunity to this disease. To this day, summer residents around the world are struggling with this problem.

Stages of development of Mildew's disease.

First stage.

It all starts in late autumn. Before winter, this disease is formed, as a rule, summer residents at this stage cannot see any hints of a disease.

Second phase.

Further, winter and Mildew's disease hibernate on plant debris. When spring comes and the temperature gives a plus, the disease germinates and can continue to develop.

Stage three.

Pathogens are introduced into the tissue of grapes and are dispersed throughout the plant. They feed on microelements in the grapes themselves.

Stage four.

In the hot season, namely in the summer, they multiply and spread throughout the plant.

Fifth stage.

Also, under the most favorable conditions for this disease, namely a temperature not lower than eight degrees and not more than thirty degrees and humid air, it can fly a thousand kilometers in just one season before autumn.

Symptoms of the disease.

As soon as the disease enters the plant in autumn, the disease cannot be noticed, and in winter too. But in spring and summer, you can see it on the leaves of grapes, namely, they become dry, like all the foliage in autumn. Further, from a couple of infected leaves, it grows into a completely diseased bush. Mildew's roots are not affected.

Weather and Mildew.

The weather, of course, affects the Mildew outbreak. The most favorable conditions for the reproduction of this disease are temperatures from twenty degrees to twenty-seven degrees and high humidity and windiness. Also, at night, the temperature should not drop below ten degrees for sure. If an abnormal heat comes, and even without rain and wind, then most likely Mildew will miss this season and shoot next year.

Manifestation of Mildew.

There are a few things to note.

• As mentioned above, it is impossible to predict and prevent this disease. After all, it manifests itself in favorable weather and it is impossible to stop it.
• It is only important to periodically examine the grape bush so that it is possible to save it in time.
• You need to know how this disease manifests itself and not push it to the approaching autumn or to insufficient lighting or watering.
• So, the leaves are covered with gray spots, which eventually lose their viable appearance.
• Then the leaves turn yellow.
• Red streaks can be seen on older leaves.
• If there are frequent rains, then on the sheets you can also find not dense and insignificant plaque.
• Of course, due to all these symptoms, closer to autumn, the leaves begin to fall out much earlier than the due date.
• Also, young leaves inhibit development and grow very slowly.
• Do not forget about the fruits, they do not look juicy, fall and do not become ripe to the end.
• This disease develops well on young and strong bushes, however, there is a possibility that this disease can also take over old bushes.

Consequences.

There are several of them and they are not very favorable:

• Due to this disease, there may be a percentage loss in the crop. It's terrible, but true.
• In rare cases, when it is possible to save at least half of the crop.
• The quality and taste of the fruit will also deteriorate.
• The opportunity to propagate this grape bush also disappears, since there is a high probability that Mildew will be transferred to subsequent bushes.
• The plant weakens significantly and the plant may not overwinter and die. And even if the plant overwinters, then its weakness will not go away and your grapes will produce much less fruit than before.

Propagation paths.

Until the end, no one understood how this disease penetrates the summer cottages. Mildew brings:

1) wind;

2) the sole of the shoe;

3) wheels of cars;

4) shovels

5) everything that touches the ground. No one is immune from this disease and there is no option to insure against it. Mildew can also hide in grape seedlings.

Ways to suppress this disease.

Several facts.

• Summer residents and gardeners are trying to cure their grapes with various chemicals.
• They pour into the ground or spray all the grapes from the topmost leaf to the roots.
• However, the use of chemicals does not guarantee that the disease will be eradicated by that percentage.
• If the weather gives a green color to the disease, then there is no point in spraying.

The only way to combat mildew is to create new varieties that are immune to the disease. Scientists have already begun to develop new varieties and this business is clearly on the way to success.

Selection.

Basically, the grapes of the old world are susceptible to this disease, because the new varieties have at least minimal immunity to mildew. There are also American varieties that have one hundred percent protection against this disease. However, the taste of these grapes leaves much to be desired. Scientists are trying to cross different varieties so that the grapes have tasty fruits and at the same time protect against this disease. Scientists have already created one such variety, Isabella. The berries may not be as tasty as we would like, but the grapes are protected from Mildew disease.

There is one caveat, and it is that nothing guarantees protection from disease. Each variety has a grade ranging from zero to five. This indicator makes it possible to understand the degree of the barrier against Mildew's disease. If the score is higher than two, this can already be considered a success. After all, if you support this result with chemicals, then this gives more assurance that your plant will not be infected with Mildew.

General agricultural technology.

If you keep an eye on your grapes, this also gives a chance that Mildew will bypass your plant. If you plant the right varieties, at the right distance, and remove the weeds often, you are much less likely to become infected. The area should be well lit, the grapes should be pruned, and the remnants should be best burned to avoid contamination.

Special treatments.

Alternatively, use chemical and biological chemicals to help protect your grapes. It is also necessary to carry out a general spraying of the grapes. First time in autumn and spring, in front of the buds. This is a kind of prevention that can really help. It is also worth cultivating the land within the radius of our grapes twice a year.

Chemical fungicides against mildew.

This is your salvation Bordeaux liquid... It was used for a long time and no one could help it like it.It is very effective, but difficult to use and prepare. Now she recedes into the background.

Difference between Mildew and Powdery.

It is important to understand and know everything about diseases. If you want to work for quality rather than quantity, it is also important to distinguish between diseases. Often Mildew and powdery mildew are confused with each other due to their lack of knowledge of the symptoms and conditions of the formation of these diseases. Oidium is formed in case of abnormal heat and lack of rain, while Mildew is formed in average temperature and humidity. You also need to remember that mildew chemicals will never solve the powdery mildew problem and vice versa.