Grapes are often exposed to a variety of diseases, it is attacked by pests. Because of this, crop losses amount to up to thirty percent, and in some cases up to fifty percent. In order to avoid crop loss and vines, the prevention of grape diseases should be carried out in a timely manner. But if suddenly the plant was struck by some ailment, treatment should be carried out correctly.
Types of diseases
All grape diseases are divided into infectious and non-infectious. The most infectious - infectious - are represented by such ailments as:
- mildew;
- gray rot;
- oidium;
- anthracnose;
- white rot and some others.
Also, all diseases are divided by the type of pathogen that causes the disease. It can be viruses, bacteria, fungi. The latter include such pathologies as black spotting, mildew and others.
Mildew
Pathogen: Plasmopara viticola Berl. et Toni.
Among the diseases of grapes, the most common is mildew, or downy mildew. This is a dangerous disease that affects shoots, leaves, fruits. With a severe defeat, grapes do not produce the next year.
The disease was introduced in the nineteenth century from America to France, and from there it spread throughout Europe and beyond. The degree of harm and the level of disease in different territories manifests itself in different ways. It depends on the climate, density of stands. Frequent rains, dew, the subtropic zone can lead to the development of severe damage to plant fungus.
You can find out about grape disease by signs. For mildew, the manifestation of the first signs is characteristic even at the stage of unfolding the leaves, but the disease can also appear on adult leaflets. Initially, a small oil stain of any shape appears. In wet weather, a white coating forms on the spot on the bottom. Gradually, necrosis occurs at the spots, covering more and more healthy tissue. First, the affected tissue turns yellow, then becomes brownish, the process of drying and dying begins. Those leaves that are affected the most, fall off. After the appearance of the disease on the leaves, it goes on to harvest. When the fruit brush is damaged, it withers.
In order to prevent the disease of grapes, in the early spring they mulch the soil under the vines, timely apply phosphorus-potassium fertilizers, remove stepsons and carry out preventive treatments with fungicides. The first treatment is carried out at a time when the shoots grow to a length of up to fifteen centimeters. The second processing is carried out before flowering, and the third - during the period when the berries reach the size of a pea. For processing, various preparations are used, which are offered in garden shops. It can be Strobi, Chorus, Kuproksat, etc.
Powdery mildew, or oidium
Pathogen: Uncinula necator Burril.
In the description of grape diseases, there is such a disease as oidium, or powdery mildew. She was brought from North America.
Signs of the disease is a lag in the growth of shoots. This can be seen at the very beginning of leaf blooming, growing vegetative mass. The loose leaves look curly, completely covered with a grayish-white coating. Inflorescences, clusters look like they were showered with ash. All affected inflorescences die off. In dry weather, diseased berries dry out, but if the weather is damp, they burst and collapse.
Oidium disease causes great damage to vineyards. The incubation period is from one to two weeks. Conidia can grow at a temperature of five degrees, however, this process intensifies at 25-35 degrees. In places where ventilation is poor, the plant is most affected.
The fight against oidium involves airing the bushes, weed control, proper pinching, garter plants. Be sure to treat the vines with fungicides. It can be the preparations “Strobi”, “Chorus”, “Topaz”, “Tiovit”.
Black spotting
In regions with high humidity, the fungus spreads intensively, affecting all parts of the plant, including lignified parts of the vine.
Symptoms of the disease are discoloration of the bark of young shoots and the formation of black dots. They grow, occupy an increasingly large area. Gradually, the spots merge together into one huge spot, the vine begins to crack, leaves and fruits are affected.
Black spotting is practically untreatable. Looking through photos of grape disease, you can see how the disease looks.
To protect the vine from black spotting, it is necessary to carry out preventive treatment of the vines. For this purpose, spring treatments are carried out at the time of leaf blooming. For this, drugs such as Ridomil, Antracol, Bordeaux mixture, etc. are used. After treatment from black spotting, the vines are sprayed with mildew and other diseases. Be sure to carry out processing in the fall, after all the leaves have fallen, contact preparations of copper.
Gray rot
Protection against this ailment is carried out in the spring. Grape processing from diseases is performed from spring to autumn.
Signs of the disease are a brown shade of berries, cracking of the skin, a grayish coating appears. There are practically no effective remedies for the treatment of this disease, but prevention helps to protect the vine from infection. For this purpose, it is recommended to grow those varieties that are resistant to gray rot. When cultivating grapes, the vines form a standard type, ensuring optimal loads.
During the growing season, the leaves are trimmed to improve air circulation inside the plant, and all extra shoots are removed. At the first symptoms of the disease, the affected clusters are removed.
Be sure to process the foliage with a solution of copper sulfate, diluting it at the rate of twenty grams of powder per twenty liters of water. You can use baking soda at the rate of two hundred grams per two buckets of water.
Chlorosis
With this type of disease, a change in the color of the leaves is observed: they become colorless, pale yellow. The development of chlorosis is promoted by cold water, an insufficient amount of nutrients in the soil, which are necessary for the formation of chlorophyll.
To protect the vines from chlorosis, phosphorobacterin dissolved in water is treated with iron sulfate added to the soil. In order to prevent chlorosis, it is imperative to carry out bush pruning only with the treatment of wounds with vitriol. In the spring, for the purpose of prevention, they are treated with a solution of iron sulfate in the morning and evening hours. The solution is made at the rate of one hundred grams of powder per bucket of water.
Anthracnose
This disease belongs to fungal. It affects shoots, leaves, inflorescences, berries.
Anthracnose is widespread in Europe, America, Asia. Basically, the disease occurs in areas with a humid and warm climate, as well as in the Black Sea coast of the Caucasus, in Moldova.
The causative agent of anthracnose hibernates on the affected parts of the vine, is able to persist for up to five years in the form of mycelium, sclerotia and pycnidia. It gives up to thirty generations of spores per season. Spring precipitation causes early damage to developing young leaves and shoots.
Symptoms of the disease are the appearance of brown spots on the leaves, surrounded by a dark white border, which often merge. Then the affected areas crack, forming deep ulcers. They can affect inflorescences, acquire a brown tint, and dry out. Similar clinical signs appear on the petioles, ridges, and berries. Most of all, the disease affects the vineyards during the rainy seasons, causing great damage.
Methods of combating the disease are reduced to the cultivation of grape varieties resistant to anthracnose, as well as to the treatment with contact systemic fungicides. The terms for processing vines from this ailment are the same as when processing from mildew.
To combat anthracnose, Antracol, Acrobat, Bordeaux mixture, Horus and other drugs are used.
Phylloxera
Phyloxera is a dangerous pest of grapes. It is distributed with planting material. Larvae form galls on the underside of the leaves, where they lay eggs, giving new generations. During the growing season, up to ten generations of the pest can develop.
The most effective pest control method is to grow varieties on rootstocks that are resistant to phylloxera. Radical methods of struggle when detecting the root phylloxera are the uprooting of all bushes in the lesion focus and in the surrounding area.
To combat ailments, they use "Actellik", "Actaru", "Confidor" and other drugs.
Spider mite
There are more than two hundred species of spider mites that parasitize on plants, including grapes. This pest got its name due to its ability to braid with cobwebs. It can be seen on the underside of the leaves, near the stems.
Ticks feed on the sap of the plant, leading to a decrease in growth and worsening ripening shoots. Sugar content is also reduced and the acidity of grapes is increased.
Carrying out treatment in the spring from diseases and pests, be sure to use such drugs that help prevent the appearance of spider mites. These are “Match”, “Actellik” and others. They also carry out the processing of vines when infected with a tick.
Fitoptus, or grape itch
Another type of tick is grape felt mite. Swollen dark areas on the front side of the leaves speak of its appearance, and impressions covered with villi are visible from the inside. At first they are pinkish-white, then they turn brown or reddish. Due to damage, photosynthesis of the leaves is impaired. If the itch affects inflorescences, then there is a compaction of the petals, a color change. Subsequently, they crumble. Most often this happens on hybrid varieties of producers.
The winter hibernates under the scales of the kidneys, at the very base of the shoots, in the cracks of the bark. In the spring he goes to the kidneys and sticks to them. During the growing season, he gives several generations.
According to statistics, not all varieties are equally affected by this disease. Those infected with phytophthus should be treated immediately.
The processing of grapes in the spring from diseases and pests is best done together. This will help prevent the infection of vines with dangerous fungal, viral and other types of diseases, and also protect the vineyards from pests.
To protect against diseases and pests of grapes, acaricides are used: Tiovit Jet, Match, Actellik.
Leaflet
Carrying out seasonal processing of grapes from diseases and pests, vines are always sprayed.
Leafworm usually damages inflorescences, young ovaries, berries. It can eat not only grapes, but also other plants. The first generation caterpillar is capable of destroying up to thirty buds, and the second - about twenty berries. Pathogenic microorganisms develop on damaged buds and ovaries, causing rotting of berries and bunches.
Leafworm can be of different types. The most common: bunch, grape, biennial.
The biennial leaflet is a small butterfly of a grayish-yellow color with a black transverse strip in the form of a triangle on the wings. Caterpillars about two centimeters long, brown-red in color. Pupa pupae short, less than a centimeter, tan. There are four pairs of hooks at the rear end.
The grape-leaf moth is a caterpillar that causes great harm to inflorescences, grapes. They turn into beautiful brown butterflies with a bluish-brown pattern on the back.
Grape leaflet is capable of affecting swollen buds, eats leaves, twists them. It damages inflorescences and berries. Butterflies of this type of pest have a yellowish color with three brown stripes. The second pair of wings of the butterfly is gray or greenish.
To combat pests and diseases of grapes, it is necessary immediately after opening the bushes to clean the old bark along with pests, diseases spores. All removed parts of the vine are burned.
Be sure to carry out the processing of chemicals. A two-year leaflet is sprayed two weeks after the start of summer of butterflies of the first and second generation. After another two weeks, re-treatment is carried out.
To combat cluster leaflets, the first treatment is carried out two weeks after the start of summer of butterflies of the first generation, the second treatment is carried out another ten days, the third - two weeks later.
The processing of grapes from diseases and grape leaflets is carried out during the swelling of the kidneys and immediately after they bloom.
For treatments used drugs "Proclame", "Match" and others.
At the first signs of the disease, you should look at the description of grape diseases with photos to find out what exactly caused the damage to the vine. But it is better not to prevent the spread of diseases and pests, but to conduct timely preventive treatments, remove leaves from under the vines, remove mulch, burn cut branches, bark. All this will help protect the vineyard and stay with a large crop.