Who does not like to eat at the end of summer delicious grapes? It is considered a very useful and easily digestible product. The content of sugar, various mineral salts, as well as vitamins in grapes is off scale. The huge variety of varieties, including those that were bred by man, is simply amazing.
Is it worth saying that healing properties have long made it a unique plant species. Many people consume its fresh fruit and love it for its taste qualities and nutritional properties.
Few people know the fact that the vine is even mentioned on the pages of the Bible. In addition, at all times of human existence, grapes have attracted considerable attention with their bright greenery, great vitality and unpretentiousness.
Therefore, it is not surprising that even in the northern part of Russia, gardeners dream of sitting under a beautiful vine and enjoying the fruits of their hard work. However, grapes are often damaged by pests, and also attacked. various diseases such as viral or bacterial. Unfavorable weather conditions and unsuitable soil often lead to poor plant yields. You can even lose half of your own crop if you do not take timely measures to protect it. Integrated system chemical and agrotechnical practices will help to preserve and increase the grape harvest.
Grape diseases description methods of treatment
Mildew is perhaps the first and most dangerous enemy plants. The disease is most pronounced during the rainy seasons. It causes great damage to grapes during the flowering period, while striking its clusters. However, sometimes at the end of July, leaves fall off the plant, which also brings a lot of anxiety to gardeners. The presence of high temperatures and hot weather can even stop the subsequent development of this disease, but, as a rule, it is already too late.
Mildew especially disfigures the leaves of the plant, as a result of which they are deformed. At first, the diameter of the lesion is not very large, but it gradually grows. The leaves of the grapes are covered with a kind of cobweb coating, and then turn brown and fall off.
However, these processes occur not only with leaves, but also with buds, flowers and fruits.
Important ways to deal with mildew:
1. Implementation of the wreckage and garters of grapes.
2. Timely cleaning of weeds.
3. Destruction of dry leaves, vines and berries that have fallen.
4. Planting resistant grape varieties.
5. Spraying the plant with Bordeaux liquid.
6. The use of stronger and effective means, for example, "Mikala" or "Kurzata".
Oidium - grape disease
Oidium is another fairly common disease that affects grapes. This disease is caused by a fungus, and it comes from America. As a result, the shoots are far behind in development, and the leaves are subject to deformation, on which there are light dust particles. This plaque is most often found on leaves in early summer. Shoots and bunches of grapes seemed to be sprinkled with flour or ash. As a rule, the affected parts of the grape die off. Berries that become infected with the disease gradually dry out, others burst or are exposed to the destructive influence of mold fungi. However, oidium causes the greatest damage to clusters, destroying them. 
The fungus spreads very quickly during periods of wet weather and high humidity. In addition, if the grapes are located in an insufficiently ventilated area, then they are much more susceptible to the influence of oidium.
Effective agricultural practices in the fight against the disease:
1. Garter shoots of grapes.
2. Timely destruction of weeds.
3. Pasynkovanie.
4. Treatment of grapes with potent effective drugs, for example, "Thiovit", "Thanos" or "Topaz".
Bacterial cancer is a grape disease that should not be underestimated. After all, the open parts of the trunk are especially susceptible to it. As a result, a bubble forms on the bark of the grape, which, in turn, gradually protrudes to the surface and breaks it. Often it reaches a considerable size, about 35 cm in diameter. The bubble breaks mainly in autumn or with the arrival of severe frosts in winter.
Effective measures to combat grape cancer
To protect the grape bush from this disease, it is mainly necessary to carry out important preventive work. Gardeners with experience know that bushes and seedlings should be protected from low temperatures and various mechanical damage. In addition, the vaccination site should not come into contact with the soil.
When cutting grapes, it is equally important to ensure that the boles do not bend. As soon as bacterial cancer is noticed, the resulting growths must be carefully cut off. Parts of the grapes affected by the disease must be destroyed immediately. Grape wounds are usually treated with solutions, such as Bordeaux liquid or iron sulfate.
In the fight against this disease, the most commonly used wood ash and various phosphorus-potassium fertilizers. The use of nitrogen fertilizers must be forgotten for several years.
By planting grapes in your garden, everyone has the opportunity to enjoy communication with loved ones and enjoy generous harvests.
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If the leaves of the grapes have changed color, spots have appeared on them, this means that a disease develops on the vine, or a pest has wound up. They are the first to react to a change in the state of the vine. Measures must be taken immediately, because the harvest is at risk for the viability of the entire bush. The choice of control measures depends on the type of damage, so every gardener needs to know what means to use to restore the health of the vine.
Grape leaflet may be one of the reasons for the discoloration of the leaves
black spot
The causative agent of the disease is a fungus that spreads in places with high humidity. It covers the entire bush as a whole, leaves, branches, berries are affected. Small dark dots form along the veins on the leaves, later they become larger. They are surrounded by a light border, the tension of the sheet becomes uneven, curl appears, and gaps form. Damaged foliage turns yellow and falls off.
The color of the bark changes, the wood cracks along, the berries rot. Helps to avoid disease:
Mildew
The disease of grapes is very common, its other name is downy mildew, the causative agent is a fungus. First, light oily spots appear on the leaves, after a few days on reverse side mycelium grows, in the form of a white fluff. Leaves must be cut off and burned. Fighting mildew is difficult, but you can, you just need to do it regularly.
To prevent the fungus from spreading, activities are carried out in early spring:
- the soil is fed with phosphorus and potassium;
- the bush is abundantly sprayed with Antrakol, Ridomil, Horus, Strobi;
- the treatment is carried out when the young shoots reach a length of 15 cm, the next spraying is carried out after the berries have reached the size of a pea;
- weeds, fallen grape leaves are harvested and burned in autumn.
If the humidity in the region is high, there is a risk of spreading the disease, it is preferable to choose varieties that are resistant to infection.
rubella leaf
Belongs to the category of fungal infections, usually appears at the height of summer due to lack of moisture or due to poor soil mineral fertilizers. The development of the disease begins with lower leaves gradually rising up. The disease manifests itself in different ways:
- white varieties develop yellowish or brown spots;
- in red species, there are predominantly shades of dark red or burgundy.
In order to prevent the disease from spreading, all diseased parts are removed and burned. As a preventive measure, the same control scheme is used as against mildew. Rovral, Mikal are suitable for processing.
oidium
It is often found on grapes, at first young shoots are affected, they become light, then a grayish coating similar to dust forms on them, they grow poorly. Gradually, the disease spreads to the entire bush, plaque covers the inflorescences, berries, tops of the shoots.
Creating good air circulation is the first thing to do in the fight against oidium:
- excess shoots are removed, weeds are weeded;
- bushes are treated with Thiovit, Horus or Strobi.
Alternariosis
The causative agent of the disease is a fungus that spreads in warm and humid weather, affecting all parts of the plant. First, spots form on the leaves with necrotic changes in the center. Then, the leaf darkens, and after the rain it covers gray coating. Later, the fungus migrates to the berries, enveloping them with a film with a metallic tint. Alternariosis in manifestations resembles oidium, the correct diagnosis can be clarified experimentally:
- the affected leaf is placed on a saucer;
- put a glass on top and place it in a warm place;
- after a while, a velvety layer of olive-colored fungus will grow.
In the spring, the bushes are treated with copper-containing preparations, Ridomil is suitable, when the berries begin to close into a bunch, Kvardis is used.
Kvardis - a drug for alternariosis
Chlorosis
The disease is associated with a violation of plant photosynthesis, characterized by a change in the color of the leaves, they lose their bright green color, turn yellow or brighten. It appears in three types:
The non-infectious nature of the disease is associated with a violation of the absorption of iron ions by the roots, which are involved in the synthesis of chlorophyll. Caused by a lack of this element in the soil, heavy soils or an excess of alkali interfere with absorption. It is easy to cure a plant if you find out the cause of the disease, and then fix the problem.
Infectious chlorosis is manifested by yellowing of the veins on the leaves, they acquire a mosaic color, therefore chlorosis is called yellow mosaic. The disease is bacterial in nature, it cannot be cured, so the diseased bush will have to be removed.
The edaphic type appears when stressful situation: high humidity, low or high temperatures. With the elimination of negative conditions, the symptoms disappear.
Fusarium
Cold and damp spring for the development of the disease is the optimal environment. The fungus appears on the upper leaves a week before the flowers bloom. First, yellow spots appear on the veins, infected shoots are distinguished by short internodes. The foliage becomes smaller, there are many stepchildren, but they are thin and weak, the growth of the plant is inhibited. This form of the disease is called kottis. By mid-June, all leaves turn yellow, but if the summer is hot, the green color returns. Berries on the affected parts of the plant become smaller, their color disappears.
The disease resembles non-infectious chlorosis, in order not to be mistaken in the diagnosis, it is required to cut a thick branch across, but a bole is better, the picture will be brighter. On the cut, dead vessels will become visible, and the wood will have a pink color.
The bush may die if the treatment with Bordeaux mixture is not started.
The mixture is also used for preventive spraying in early spring. The vine reacts well during this period to feeding with ammonium nitrate, it helps to save the bush.
Fusarium yellow spots appear on the veins of the leaves
Leaf curl
The disease is common in Europe, often of bacterial origin. Sometimes curl appears on the leaves due to unfavorable soil or weather conditions. The edges of the leaves begin to curl inward in mid-summer. At first, this happens on the lower branches, after which the upper tiers undergo changes, the color of the green turns pale.
The bush is oppressed, it does not develop as actively as healthy plant, the yield is unstable, the quality of sugar content often suffers. The virus is transmitted by vaccination, so careful selection is the main condition for the health of grapes.
grape pests
The invasion of pests is also a concern for gardeners, some of them are extremely voracious and capable of destroying the entire bush in a few days. It is necessary to start fighting them as early as possible, even in the spring, when the larvae of ticks and caterpillars are just starting to wake up, otherwise it will be more difficult to get rid of them.
This smallest aphid is one of the most dangerous pests grapes. It was brought to the European continent from America. First, it came to France, where it destroyed most of the vineyards, capturing the areas of Germany and Spain, then spread everywhere.
Being sucked into the leaves, she drinks their juice, at the site of bites, the damage is clogged with dirt, after which rotting begins, swelling is formed. If phylloxera is not fought, it will destroy the entire vineyard in five years, therefore, as soon as it appears, urgent measures must be taken:
- aphids do not tolerate sandy soils, so you can add sand under the bushes;
- she does not like importance either, so timely watering is also necessary;
- to destroy insects, the bushes are treated with a solution of Hexachlorin.
Phylloxera is manifested by characteristic tubercles on the leaves
spider mite
This pest is a real misfortune for gardeners, the tick settles on many shrubs, and does not bypass grapes. Usually lives in weeds that have grown near the bush, then moves to the underside of the leaves of the vine. It is not difficult to notice a tick by carefully examining the bush; its presence can be determined by a thin cobweb on the back of the leaves. Depending on the variety and color, the foliage of the grapes turns red or yellow, then falls off. The tick sucks out nutrients, as a result, the bush is oppressed, loses productivity, and the quality of berries decreases. The bulk of the shoots do not have time to ripen by autumn.
To combat the tick, take the following steps:
- do not allow the growth of weeds:
- in the spring they spray with DNOK or Nitrafen;
- treatment from a tick is repeated at the end of June.
The main condition for processing is thoroughness, it is important that the drug gets on inside leaf where the tick is located.
The tick disrupts the process of photosynthesis
This is also a tick that prefers to settle on grapes, feeding on its juices, the pest disrupts the process of photosynthesis in the plant. The leaves where it is located are recognized by the curly, tubercles located on the upper side, later they become red or Brown color. If the sheet is unfolded, fleecy depressions will appear inside. Measures to combat grape mites:
- in early spring, prophylactic treatment with DNOC is mandatory;
- at the time of bud break, an insecticide is effective - Phosphamide;
- if it was not possible to cope with the tick, the treatment is allowed to be repeated in the summer.
leaf roller
This type of pest belongs to the butterfly family; larvae are dangerous for grape leaves - caterpillars of winged insects damage young shoots, leaves and flowers of the plant. Having rolled the edge of the leaf into a tube, entangling it with cobwebs, the caterpillar creates a shelter for itself, then it braids other leaves. They dry slowly, gradually forming brown bundles, a reddish hue. If you open them, you can see the caterpillar.
How to fight:
- the old, exfoliated bark is removed and burned in the spring, leaflet pupae are hiding there;
- for spraying, Talstar, Fury or Zolon preparations are suitable. They process the bush carefully, trying to get the solution on all the wood, in every crack.
There are many diseases in grapes, but most are easily prevented in the spring, when the vine opens after wintering. Timely processing is the key to the health of the plant, you need to observe the regularity, frequency and dosage of the drug, so as not to harm the vine and yourself. Proper Care will complement preventive measures, then the grapes will delight in the fall with beautiful heavy clusters.
Gentlemen of the vinedressers, as the old saying goes, you need to know the enemy by sight. I present to your attention the main diseases and pests of our vineyards. The article will only short description, photos and videos of the most common pests and the most dangerous diseases. You can find out more about the treatment and methods of dealing with each of them by clicking on the heading with the name of the disease that interests you or the link “read more…”
Without exaggeration, this fungal disease can be called one of the most common and most dangerous diseases in our vineyards. Without the use of preventive measures in the vineyard, the disease can cause enormous damage to the vine plant. The infection affects both all green parts of the plant and the crop. most susceptible to this disease European grape varieties. Most varieties of American breeding, on the contrary, are not very susceptible to mildew.
Like mildew, oidium is a common and dangerous fungal disease. The causative agent of this disease is a relative powdery mildew apple trees, currants and other horticultural crops. The disease causes the greatest damage to inflorescences and berries of grapes. The disease affects to varying degrees both almost all varieties of European and American breeding, and their hybrids. The fight against the disease is carried out with the help of contact preparations
Anthraznoz.
Anthracnose is a disease caused by imperfect fungi. Gloeosporium, Colletotrichum, Kabatiella. It is also called "bird's eye" for the similarity of the lesion pattern with the eye of a bird. The disease affects both leaves and petioles, bunch ridges and young shoots. Shoots and clusters affected by anthracnose gradually dry out and die completely. The most susceptible to the disease are grapes before and during flowering.
The felt mite is a fairly common type of mite. The tick spends the winter in the scales of the buds of the grape plant. During the growing season, the pest is located mainly on the underside of the leaf. With a massive infection of the vineyard with a tick, it is possible to damage not only the leaves, but also the bunches of grapes. Hot and dry weather greatly contributes to the development and spread of felt mites.
noninfectious chlorosis.
Chlorosis is the inability of a grape plant to produce chlorophyll due to a lack of iron. The leaves are getting lemon color, ovaries lag behind in development or fall off, shoots grow weakly. Rainy summers or excessive watering are favorable for the appearance of chlorosis. The disease can be attenuated or prevented by applying to the soil iron sulphate, prevent water stagnation in the vineyard
Alternariosis.
Wasps are the main pest for the grape harvest during its ripening period. In a year favorable for the development of the wasp population, the number of this pest increases many times, and the wasps are capable of inflicting irreparable damage to the grape harvest in just a few days, up to its complete destruction. The fight against wasps must begin long before the start of maturation of the bulk of the crop. It is best to take preventive measures to reduce
It affects all above-ground parts of the plant, but causes especially great damage to bunches of grapes. The main methods of struggle are high agricultural technology in the vineyard, good ventilation, timely treatments for fungal diseases. When infected, grapes first turn brown or grey colour, then a gray coating appears
Bacterial cancer is, without exaggeration, a deadly disease of the grape bush. At the moment, there are no drugs for the treatment of this disease. Infected bushes must be uprooted and removed from the vineyard. If possible, dig up and remove as much of the damaged plant's root system as possible. It is not difficult to diagnose the disease. On infected bushes, growths of cancer cells appear, rapidly increasing in size. Cancer-causing bacteria are present in all parts of an infected plant and can be transmitted from planting material or when using secateurs on healthy and diseased bushes without disinfectant treatment when pruning.
Black spot on grape leaves.
black spot - fungal disease of a grape plant capable of infecting all organs and tissues of a grape plant, without exception, including perennial wood. Pathogen Phomopsis viticola according to the method of nutrition, it belongs to the group of facultative saprophytes, that is, it is able to penetrate through stomata or wounds into the tissue of the host plant and spread in its uppermost layers under the epidermis, causing necrotization of parenchyma cells.
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Every gardener dreams of getting a rich harvest from his vineyard. But for this there is little knowledge about how to properly care for grapes. It is necessary to get acquainted with grape diseases and methods of their treatment.
Grapes are susceptible to a variety of diseases, including leaf rubella
Types of grape diseases
An important method of combating diseases is spraying the bushes. It is better to start doing it before the buds open. The bushes should be sprayed in the spring with a three percent solution of Bordeaux mixture. Method of preparation: dilute 300 g of copper sulphate in 5 liters of warm water and mix, dilute 300 g of freshly slaked lime in another 5-liter bowl, then mix both solutions, pouring blue vitriol into milk of lime. After mixing and straining our mixture, pour it into the sprayer. Now you can process the entire vineyard, including young growth and perennial bushes. Such prevention protects grapes, but does not completely save from diseases. Therefore, let's take a closer look at grape diseases and arm ourselves with ways to deal with them.
Diseases of grapes are divided into two types:
- Infectious - these are diseases that are transmitted from diseased bushes to healthy ones through viruses, fungi or bacteria. The danger lies in the fact that under certain favorable conditions, the infection can destroy the entire vineyard completely. The transmission of the disease is possible by wind, water, animals and even working garden tools. Everyone needs to fight accessible ways: disease prevention, high agricultural background and quarantine.
- Non-infectious - these are diseases that occur due to adverse weather conditions, soil acidification or an increase in its alkaline balance. If there is a weak development of the vine, cracking and drying of the color of the ridges, shoots with short nodes, then you should immediately take measures to treat the diseased bush.
Below we consider the description and signs that characterize grape diseases.
Leaf discoloration may be a sign of non-communicable diseases in grapes
In other words, this disease is called ashtray or powdery mildew. It is caused by a fungal infection that affects not only foliage, berries, shoots, but also the inflorescences of a grape bush. This disease is easy to detect by the presence of an ash-gray coating on the leaves of the plant, which quickly wither and dry.
Oidium hibernates on the vine in the form of a dense mycelium, and in summer, with the onset of warm and humid weather, the mycelium sprouts. Spores are formed - sidium, which are carried by the wind throughout the vineyard and cover the greens with a powdery coating. Affected shoots grow weakly, and the fruits generally rot or dry out. The oidium reproduces with its spore sidium throughout the warm season, so it is necessary to constantly carry out all the common preventive procedures that we met earlier in this article.
Oidium - a fungal infection of grapes
In another way, downy mildew. This disease affects all parts of the grape bush and is a danger of death for the entire vineyard. The disease manifests itself in the fact that the leaves begin to lose their shape, and their green color seems to be smeared with dirty oil. When the temperature rises in summer, the disease progresses, covering the underside of the leaves with a gray cobweb-like bloom. Then the leaves change their color to dark brown, dry out and fall off. We observe the same picture with the ovary, inflorescences and fruits of grapes, which are the size of a pea. The fungus does not affect large fruits.
Mildew usually hibernates in fallen leaves (winter spores), and germinates in zoosparanga in summer at a temperature of 13 degrees and humid air. The incubation period for the spread of downy mildew is the beginning of May - the end of July.
The emerging spores easily move with water, affecting the organs of the vine and penetrating into the depths of the plant tissues. Growing, the mushroom thread covers the grapes with oily spots.
To prevent infection of the vineyard with mildew disease, the following conditions must be met:
- Do not plant grape bushes in lowlands, where moisture often lingers after fog or dew.
- Comply with the conditions of ventilation and penetration of sunlight.
- Mandatory cleaning of foliage.
- Timely treatment with Bordeaux liquid.
Mildew occurs in conditions high humidity
Anthracnose
This is a fungal disease. Widespread in vineyards located in areas with a warm and humid climate (Black Sea coast, Moldova, Ukraine).
Anthracnose fungus affects almost the entire bush. Long stored in the form of pycnidia, sclerotia and mycelium (up to 5 years). After overwintering on the affected parts of the bush, about 30 generations of spores mature during the season, which infect more and more new areas of the vineyard.
The disease is manifested by the appearance of brown spots with a white border on the leaves of grapes. In the middle of the spots, the green tissue dies and falls out. Brown, and then pink-gray circles with dark edging are also formed on the shoots. The fabric cracks, deep wounds appear. Shoots break, dry and die. The disease leads to the death of most of the crop, causing great damage to gardeners.
Anthracnose of grapes is manifested by brown spots on the leaves
Chlorosis
This disease in the grape bush causes a metabolic disorder. The formation of chlorophyll occurs with disturbances, so the process of photosynthesis obviously slows down. If you notice that your vine is practically not growing, and the leaves are strangely yellowing, it's time to sound the alarm. Your vines are sick.
There is infectious and non-infectious chlorosis. If a focus appears, then chlorosis affects not only the grapes, but also all the plants that are around.
It is necessary to pay attention to the composition of the soil of the vineyard. If there is an excess of lime, a glut or lack of minerals, then this often leads to this disease.
It is necessary to qualitatively change the condition of the soil, and at high humidity to carry out drainage work.
Unnatural yellowing of leaves - the first symptom of chlorosis
white rot
A fungal disease that affects grapes after a hail, sunburn and Mildew. At first, the fungus affects the stalks, gradually moving to the berries. This directly threatens the entire crop, because grapes affected by white rot are bland and tasteless.
The fungus overwinters on fallen berries and leaves. To successfully fight this disease, it is necessary to carefully remove diseased berries, because they are the main source of the disease.
Gray rot
A disease that can destroy the entire crop. Diseased grape fruits shrivel, after which they burst and acquire a rotting gray coating. Such bunches of grapes are not suitable for storage and transportation.
There are no effective measures to combat this disease, it is important to comply with all preventive measures for growing crops.
Gray rot destroys the berry crop
black rot
Fungal disease that affects shoots, leaves and berries. They call it so because the sporulation of the fungus is black. The fungus spends the winter in the soil or on a grape bush, and then infects the plant during rain.
The disease is manifested by the fact that depressed brown spots appear on the berries. Over time, they acquire a purple hue and increase in size. The berry turns black and crumbles.
Spraying with Bordeaux liquid is the most effective in the fight against black rot.
acid rot
Drosophila fly (fruit fly) damages the berries of a grape bush when ripe. This insect quickly decomposes and utilizes fruits with semi-liquid pulp.
Acid rot is the rotting of brownish berries in ripe bunches of grapes. Prevention will be the removal of spoiled berries, dusting the crop with garden sulfur.
If you do not remove the affected berries, acid rot will spoil the entire bunch.
Escoriosis
In other words, black spotting. In the summer, at the beginning of June, signs of the disease can be observed. Dark spots appear on the shoots of grapes and leaves. They blur into oval spots and fade. Even grape buds are covered with these spots.
It is very difficult to fight this chronic disease, but grape bushes need to be treated regularly.
Necrosis
This disease is also called dry arm, because it is manifested by the drying and extinction of the vine. the main problem in that this disease is not visible on the surface of the cortex, because the spots form inside, joining in a ring. The main way to deal with necrosis is prevention. Do not cover the vine for the winter with an earthen layer; it is better to use cellophane or other insulation.
bacterial cancer
A plant disease caused by a rod-shaped bacterium. Small white growths form on the vine. Then they acquire dark color and become hard. Such tumors occur at the sites of vaccinations or other mechanical damage through which bacteria penetrate. A diseased plant develops poorly or dies quickly.
Measures to combat bacterial cancer are cutting tumors to healthy tissue and treating mechanical damage with a 5% solution of copper sulphate.
Growths of bacterial cancer must be cut off and treated with copper sulphate
rubella leaf
This is a common disease of dyed grape varieties.
In summer, at the end of June - in July, a red tint can be seen on some leaves. This is the first sign of rubella leaves. Then the leaves slowly thicken, become brittle - the necrosis of living tissues begins.
Leaf rubella often occurs if there is not enough potassium in the soil or after a long drought. To cure grapes you need:
- enrich the soil with potash fertilizers;
- spray grape bushes with potassium nitrate.
It can be concluded that the usual prevention saves the vine from most diseases. This includes checking each seedling for grape disease, regularly destroying diseased bushes, trimming off unwanted leftovers - these are all common preventive measures for the health of your vineyard.
Most grape diseases can destroy the crop or significantly reduce the quality characteristics of the berries. For this reason, fighting them is extremely important. Among diseases most widespread received mildew grapes. Treatment of this disease is carried out in accordance with the method of combating fungal infections of plants.
A particular danger of fungal diseases is the rapid spread of infection. They are able to cause significant damage to the plant in a few weeks and dry the grape bushes within 1-2 seasons. The rate of spread of the disease depends on the type of infection and weather conditions. For example, mildew (downy mildew fungus) actively spreads in rainy weather, while oidium (vine uncinula mushroom) completely stops development during rain.
Disease control measures should take into account the prevalence of infections in the growing area. In the middle and southern strip of Russia, mildew grapes are most often sick. Treatment for a fungal infection is as follows:
- preventive measures - spraying with antifungal drugs, pruning unnecessary shoots, tying the vine, removing diseased leaves and branches, removing weeds, etc .;
- maintaining and strengthening the agricultural background;
- preventing the spread of diseased plants and fruits - quarantine.
Mildew is the most dangerous fungal disease
Affecting inflorescences and berries, the fungus completely destroys the crop. The leaf cover of grape bushes dries out under the influence of the fungus, after which it falls off. A sharp reduction in the area of deciduous surface disrupts the process of proper ripening of fruits. The berries of sick bushes lose their nutritional value and sweetness, the wine made from them tastes sour. A diseased vine does not ripen well, this negatively affects the bush's resistance to winter cold.
The fungus, affecting the plant, develops especially actively on young inflorescences from individual pedicels or ridges. The areas affected by the disease turn brown, all ovaries with inflorescences below die. Under the influence of rain, the fungus actively spreads and destroys the plant.
Mildew distribution conditions
The fungal infection overwinters as spores on fallen vine leaves and soil. In the spring, when the soil becomes very wet, and the air temperature stays at 10 degrees for 7-8 days, the fungus spores swell and germinate.
Visually, the development of the disease begins with small spots. yellow color, over time, covering the entire area of the sheet. A sign of the spread of the disease is the appearance of a white fluff in the lower part of the leaf formed after rain. Infected leaves turn completely yellow and die. Recognize mildew on vine can be on spots that look like small dots of a brownish hue.
The microorganism poses the greatest danger to young inflorescences, since sporulation of the fungus is formed on their surface. Young inflorescences die under the influence of mildew - the berries turn black, wrinkle and crumble. The spread of the disease stops in dry hot weather, air temperature above 30 degrees.
General rules for dealing with the disease
If mildew grapes are infected, treatment is carried out by spraying with a pesticide that destroys the primary foci of infection. Before the grapes begin to bloom, the bushes are sprayed with antifungal mixtures. The next stage of spraying begins immediately after the start of flowering and the appearance of small berries (the size of a match head). Consider the methods of combating the disease in more detail.
Mildew countermeasures
The main stage of the organization of the struggle is to provide conditions that prevent the development of the disease. The infection that contributes to the development of mildew lives in places of high humidity, in lowlands, which for a long time retain rain puddles, dew and fog. A complex of agrotechnical works contributes to better ventilation of plants and eliminates the accumulation of excess moisture near the grape bushes.
As mentioned, mildew spores overwinter in fallen grape leaves. In autumn, after the end of the harvest, fallen leaves must be burned.
Spraying vine bushes with poisons that destroy fungi is the most effective way to preserve the crop. As a rule, they are made with a 1% solution of Bordeaux mixture. For the first spraying, a solution of 0.5% is used, subsequent treatment is carried out with an increase in concentration from 0.75% to 2%. The low content of the active substance prevents the antifungal solution from burning leaves and shoots infected with grape mildew. Treatment (the photo below shows the process) involves spraying the vines with a tank mixture in order to prevent infection.
Antifungal mixtures for spraying grapes
There are various folk methods and preparations for the fight against mildew grapes. Treatment folk remedies effective as a preventive measure. Effective way treatment - spraying with solutions containing active chemical components. Antifungal solutions contain zinc and are the most affordable and effective drug is a solution of Bordeaux liquid for spraying.
Characteristics of the active component of the Bordeaux mixture
It should be remembered that a solution in a concentration of more than 3% copper sulfate can burn the surface of grape leaves. The main active component of Bordeaux liquid is characterized by rapid dissolution in water, so rains in short term remove the medicinal mixture from the surfaces of the grape bush.
In order for the solution of copper sulphate to remain on the surface of the plant for as long as possible, it must be mixed not with water, but with milk of lime. Lime neutralizes the acidic reaction of copper sulfate, the liquid becomes viscous and sticky. Adhering to the substance is retained on the surface longer under the influence of rain.
In order to effectively fight grape mildew, treatment should be carried out with a product that is prepared according to technological standards. The quality characteristics of all components are important.
Paying attention to the main active ingredient - copper sulfate, you should make sure that the powder does not contain foreign impurities, and its color is bright blue. Lime for the solution is suitable for both slaked and quicklime. However, it is better to perform quenching during the preparation of the solution. It is freshly slaked lime that ensures the best adhesion of the drug to the surface of grape leaves.
The proportions of the Bordeaux mixture solution
All preparations for the treatment of mildew in grapes have a predetermined safe concentration of the active ingredient. The concentration of copper sulphate in a solution of Bordeaux mixture can be from 0.5% to 3%, a higher content of the active substance will burn the leaves. To prepare 10 liters of the drug with a concentration of 1% of the active substance, you should take 100 g and the same amount of copper sulfate. Mixing is carried out in a container, the material of which is resistant to chemical reactions and does not interact with the components of the solution. The best option- glass or ceramic container, use of galvanized or metal containers is unacceptable.
To prepare the mixture, dilute copper sulfate with one liter hot water. As soon as the powder dissolves, another 5 liters are poured into the container. cold water. Separately, 100 g of prepared lime is quenched, after which the rest of the water is added and the volume is adjusted lime mortar up to 5 liters. The lime preparation is filtered. A solution of copper sulphate is gradually added to the resulting milk of lime. The process of combining the components is accompanied by constant stirring.
It should be noted that a solution of copper sulfate is added to the lime solution, and not vice versa. With an incorrect sequence of actions, the resulting suspension will be ineffective in the fight against mildew, the active components will precipitate.
Characteristics of a properly prepared preparation
A solution of Bordeaux liquid, which is prepared in accordance with the technology, has a blue color and a mucous structure that sticks to the fingers. Color can signal the concentration of the active substance. For example, green means that copper sulfate is added in excess, and when sprayed, the liquid will burn the grape leaves.
Sick mildew grapes? Treatment: how to treat with Bordeaux mixture?
If during a visual examination it is established that the grapes are sick with mildew, treatment with a Bordeaux mixture solution is optimal solution. To ensure the safety of the prepared product, a metal nail is briefly immersed in it. If the nail is not covered with plaque when the nail is removed, the solution is safe for plants. The appearance of small grains on the surface of the nail will indicate the low quality of Bordeaux liquid and the high content of the active ingredient. In this case, it should be further diluted with lime mortar.
However, the Bordeaux mixture, prepared in accordance with the technology, is also capable of harming the grapes if spraying is performed on a hot day that comes after heavy rain. In order to minimize the risk of plant scorch, treatment is carried out at dawn or at sunset.
Prevention of viral and fungal diseases of grapes
The maximum effect is given by measures for the prevention of fungal and viral diseases. Prevention is carried out during the period of three seasons: spring, summer and autumn. During this time, growers water the bushes, cut the vines and strengthen the agricultural background by fertilizing the soil.
Before spraying the grapes, it is necessary to remove damaged leaves, trim excess shoots and tie up the vine. Garbage in the form of diseased foliage and shoots must be burned to prevent the development of infection.
Grape care before harvest
It is extremely important to carry out mildew treatment on grapes in July. In summer, before harvesting, plant growers perform the main spraying of bushes. The schedule for processing with a Bordeaux mixture solution is every 3 weeks, starting from the first days of July. Spraying of grapes with antifungal drugs is completed in the first decade of August and is not carried out until the vines are pruned.