How to deal with black spot on grapes. Black spotting. Anthracnose: features of the defeat of the grape bush and the fight against the disease
We treat diseases.
In my opinion, disease is the only deadly threat to the vine. The most delicious and beautiful varieties most affected by disease. Despite the efforts of breeders, this law has not yet been overcome. Carriers of genes for resistance to mildew - the most formidable disease - are varieties with a mediocre taste, high acidity, and, like Isabella, a sharp "fox" aftertaste. Unfortunately, when trying to cross grapes tasty and stable, good offspring for a long time could not be obtained - disease resistance genes are transmitted only with bad taste. But now there is hope that with the help of genetic engineering it will be possible to obtain varieties of the highest quality. It will soon be possible to assemble the grape genome "brick by brick" from several parents, placing in it genes that protect against diseases and pests, and taste, and aroma, and color, and everything that is good in different varieties and forms.
But for now do protective treatments will definitely have to. Moreover, according to the scheme and on time, alternating preparations.
Descriptions of diseases are not arranged in alphabetical order, but according to the degree of their prevalence and harmfulness to grapes.
initial stage
mass defeat
Alternariosis
Downy mildew, grape pernosporosis, the most dangerous disease of grapes, is widespread - wherever there are vineyards, there is mildew. The causative agent is a fungus. Lives on living tissues. It affects leaves and green shoots. The fungus overwinters in spores on fallen leaves and soil, easily tolerates frost and heat. In spring, it germinates at a temperature of 10 C. With wind or rain splashes, the spore falls on the reverse side of the leaf.
During the season there can be up to 20 generations of the fungus, only the complete death of the plant or a decrease in temperature will stop the reproduction of the pathogen
up to + 13 C.
Outwardly, the disease manifests itself as the appearance of numerous yellowish spots.
In wet weather back side the leaf, due to the active reproduction of the fungus, is covered with a moldy coating. There is no flight in dry weather.
If the variety is resistant to mildew, the symptoms will be more blurred - the spots will be small, dry quickly, and may look like needle punctures with dried edges. The leaf thus acquires an oily sheen.
Spots appear on infected green shoots - oblong, first yellowish, then brown. Later, they, like the leaves, become moldy.
The tops of the shoots on unstable varieties can be especially affected. Then the inflorescences are affected, the clusters of berries that have just started. If the infection occurs later, when the berries are already large, bluish-gray depressed spots form under the stalk. Later, sometimes already colored berries shrivel, turn brown and fall off.
Only a system of preventive, advance treatments will prevent the outbreak of this disease in your vineyard and protect your crop.
-
powdery mildew, ashtray - fungal disease grapes.
It affects all green parts of grapes at any time during the growing season. Like most fungal diseases of plants, it came to Europe from America in the middle of the 19th century. It is found everywhere where grapes grow. It causes especially great damage where there is an early spring and a moderately warm summer.
The fungus - the causative agent of oidium - lives only on living tissues. Winters in cracks in the bark, kidneys in the form of mycelium - mycelium. In the warmest areas of grape cultivation, oidium appears very early - freshly sprouted shoots can be completely covered with a moldy coating. In other regions, the disease appears later on leaves and clusters in the form of individual spots. Pathogen activation time - temperature +25 C and high humidity. At this time, the plaque appears on both sides of the sheet, it is compacted and becomes bright.
Oidium remains on the plant throughout the season and continuously produces spores that can immediately germinate and form new vine lesions. Closer to autumn, the plaque grows so much that it becomes like felt. The leaves turn yellow, become covered with a dirty gray coating, and bend. Young bunches and flowers dry up. If the infection occurs during the filling of berries, the skin and pulp crack, the seeds turn outward. This is a very characteristic feature for oidium.
Young green shoots may become moldy. With a strong defeat from the bushes, it can smell like rotten fish. Brown spots of irregular shape sometimes appear on the old vine.
Contributes to disease outbreak warm winter, warm damp spring. Unlike mildew, prolonged rains stop the spread of oidium. The disease can completely destroy the crop and weaken and then destroy the vineyard in 2-3 seasons.
You can fight oidium with the help of colloidal sulfur, ground sulfur, Thiovit-Jet, Topaz, Skor, Bayleton.
You can see the terms and frequency of processing
or
On the page
Fungal disease of grapes. Distributed everywhere.
In recent years, it has been increasing its harmfulness more and more. Hot, humid weather favors the disease. It affects leaves, petioles, shoots, berries. The disease looks like an oidium - the shoots are covered with brown or silver spots. Light spots first appear on the leaves with characteristic necrosis in the center, then the leaf darkens and becomes covered with mold in wet weather. On the berries, the fungus forms a film that gives them a light metallic sheen, then a velvety coating forms. They shrivel, and the taste becomes spoiled and unpleasant. If the clusters were infected in the field, but the development of the disease, for example, due to dry air, did not occur, then the fungus will easily start growing during storage and spoil the already harvested crop.
To distinguish Alternariosis from oidium, you can place the affected part of the shoot or leaf on a damp saucer, cover with a damp glass and put in a warm place - after a few hours, if it is Alternaria, the material will be covered with a velvety coating of olive color. Because of this, this disease has another name - olive blotch.
Fungal disease of grapes. Distributed everywhere. It spreads most actively during heavy rains with hail, causing mechanical damage. The pathogen is activated in a humid environment in a wide temperature range from 2 to 30°C. For the season can give up to 30 generations. Young leaves and shoots are affected in spring. Brown dry spots 1–5 mm in diameter appear on the leaves, surrounded by a brown-black border, sometimes with angular edges. The affected areas are often numerous, they can merge with each other or remain single. The center of the spot dries up and becomes gray-white. Dry patches often fall out and give them a "perforated" appearance. Young leaves are most susceptible to infection. Spots can cover the entire leaf, but are more common along the veins. When the necrosis affects the veins, especially on young leaves, the normal development of the leaf is disrupted, resulting in malformed or desiccated leaves. At the same time, the tips of the shoots with young leaves look dried up and as if burned.
Young green shoots are most susceptible to anthracnose. In the spring, symptoms of an early infection may appear from the opening phase of the first leaf on the leaves and shoots of the vine. Depressed brown-brown, violet-brown or violet-black spots form on them. At further development fungus, they acquire an oval shape and a pinkish-gray color, and can also be combined with each other. The death of shoot tissues causes longitudinal cracking of the bark, sometimes to the core. Wounds take the form of extensive ulcers. Shoots become brittle and break.
Anthracnose also affects leaf petioles and ridges of brushes. Damage to shoots by anthracnose can be confused with hail damage. The differences between them are that the edges of the wounds caused by anthracnose are raised and have a black color.
The brushes are especially susceptible to anthracnose before flowering and before the berries begin to ripen. The damage on the ridges is the same as on the shoots. Diseased inflorescences dry out completely. If the cluster is pinched by necrosis, then the part of the brush below the necrosis fades.
A sign of damage to berries by anthracnose is spots, sometimes rounded, sometimes angular, depressed, brownish or gray, surrounded by a narrow dark border. The center of the lesion at first has a purple color, gradually becomes velvety. In general, the pattern of spots is similar to the image of a bird's eye, hence one of the names "Bird's eye". Berries may crack.
If the diseased parts of the plant are placed in a moist and warm environment, then an easily flaking pink or pink-orange coating will appear on them.
The pathogen hibernates in affected shoots and in mummified fruits (lasts up to 5 years). At a temperature of 24–30 ° C and with frequent rains incubation period lasts 3-4 days. In dry weather, the spores of the fungus stick together into lumps and do not germinate. In the presence of a sufficient amount of moisture, the mucus swells, and with drops of rain or watering are transferred to other plants.
The first treatments are carried out with contact preparations based on copper at the time the shoots grow by 5-10 cm, further treatments with systemic fungicides Ridomil, Skor, Arcerid, Acrobat) should be carried out with an interval of 10-14 days. After hail falls, it is imperative to treat with fungicides against anthracnose as soon as possible.
bacterial cancer
Bacterial disease of the vine. Found everywhere. The causative agent is a mobile bacterium that penetrates the plant through wounds. Under its influence, normal cells turn into tumor cells. Galls (growths) form on the shoots, which causes vascular obstruction. This leads to a disruption in the growth and development of parts of the shoots located above the tumor. The main source of infection is planting material and infected tools. Reliable chemicals there is no fight. It is impossible to eradicate the pathogen from an adult plant. Sick plants, when the first signs appear, are best removed from the site and burned. In place of the affected bush, you can not plant grapes for at least 3 years. In the literature, there are indications that it is possible to improve planting material by placing pharmacy oxytetracycline in a solution. Treatment of diseased bushes at a concentration of 500 units. solution every 2 weeks delays the development of the disease on adult bushes for 2 years. This method has not been proven to be safe. In Australia and the United States, a group of soil microorganisms has been identified that are natural antagonists of causative agents of bacterial cancer.
Apoplexy
Sudden and complete death of the plant. It is caused by some types of pathogens - verticillosis, fusarium, armillariasis. These pathogens are capable of producing toxins. When pathogens enter the conducting system, plants cause general poisoning. The foliage instantly fades, the plant dies before our eyes. In this case, single bushes suffer. Apoplexy occurs in hot weather in weakened or depleted plants.
Gray rot
A fungal disease that affects many types of plants, is widespread everywhere. It can affect shoots, inflorescences, tendrils, berries and leaves. Harvest after a fungus attack is not suitable for food. In humid weather, the foci can become covered with a dense gray coating, which dusts when touched. In hot and dry weather, the disease proceeds according to the type of noble rot - the berries wither and accumulate a large amount of sugar. You can make wine out of them.
Verticillosis (wilt).
-fungal disease. The disease develops in hot weather 2-3 years after planting, until then the disease develops asymptomatically. The pathogen enters the plant through wounds and root hairs (through the soil). The course of the disease is characterized by rapid withering of the shoots and the death of the plant - apoplexy. In a less acute form, the leaves gradually turn yellow, turn brown and fall off partially or completely. In annual shoots, the nodes lignify unevenly. If you cut across thick roots, stems or withered shoots, then black-brown necrosis is visible on the cut. The pathogen persists for 4 - 5 years in the soil, often infects strawberries - it is not recommended to plant vineyards in areas from under this crop. Other preventive measures include the removal of weeds that may be carriers of the pathogen.
Treatment has not been developed. If the bushes do not die within 5 - 6 years, then they spontaneously recover completely.
Armillariasis
A fungal disease that affects more than 200 plant species. Develops on the roots. The fungus penetrates the root bark, releases extremely toxic toxins. Poisoned wood dies and mycelium settles in it. The penetration of the pathogen causes white peripheral rot. The disease appears in the spring. Leaves wither. The roots become brown, soft, rotten. On inside bark formed white films of mycelium. Even one focus of infection can lead to the death of the entire plant. In autumn, with the onset of a wet period, fruiting bodies of the fungus appear on diseased or dead plants - legs 5 - 15 cm tall, caps - 4 - 12 cm in diameter, brown-yellow.
To prevent the spread of the disease, dead plants must be immediately removed and burned, the soil should be shed with a solution of copper sulphate. To prevent the transition of mycelium from natural foci to the vineyard, the vineyard is separated from the forest, forest belts, neglected areas, by a ditch.
Viral diseases
Group infectious diseases that cause viruses. Little has been studied about the virology of grapes, most diseases have only been described, there are about 35 in total. The pathogen is transferred from a diseased plant to a healthy one only with infected juice - vaccination, sucking insects, nematodes, pruning with the same tool of the patient and healthy plant, propagation by parts of an infected plant. The picture of the disease is always different - sometimes the plant can be an asymptomatic carrier of the virus (due to good immunity or varietal resistance), in some specimens the viral infection may have a vague, fuzzy picture, and in some cases the disease proceeds quickly with pronounced lesions.
The first group - NEP viruses - suspected to be spread by nematodes and planting material - cause:
Short knot grapes - the leaves at the same time curly, take an asymmetric shape, the venation becomes abnormal. The internodes are abnormally short, alternating with normal ones, the nodes are sometimes double, the shoots are flattened and forked. Berries fall, bushes degenerate.
yellow mosaic vine - in spring, young leaves and shoots are yellow, then yellow spots or stripes appear on the leaves. Clusters are small with peas of berries. Bushes practically do not grow and degenerate.
vein fringing - in late spring - early summer, chrome-yellow stripes appear along the veins. Growth stops, bushes wither.
Rezuhi mosaic virus (mosaic arabis), Tomato black ring spot virus, Raspberry ring spot virus, Strawberry latent ring spot virus
- less harmful viruses, may not show themselves for a long time, when the plants are weakened - general lethal symptoms appear - a sharp stunting, curling of the leaves, uncharacteristic coloring of the shoots and leaves, and ultimately the death of the bushes.
Similar symptoms - variegated color, leaf deformation, growth and development lag, striated wood, discoloration of young shoots giveGrape ring spot virus, Grape chromium mosaic virus, Grape rosette virus
and others.
From diseased plants, moreTobacco necrosis virus, X-potato virus, Tomato bushy dwarf virus, Alfalfa mosaic virus.
The understudied areAsteroid (star-shaped) mosaic of grapes
(random chlorotic leaf spots with central necrosis and leaf deformity),Ainashiki's disease
- disease manifests itself ripe berries(sugar in berries decreases, ripening is delayed, an unpleasant taste appears),Disease of enations of grapes
(parallel outgrowths 0.3-5 cm long and 0.2-0.3 cm wide appear on the lower leaves, the leaves are deformed, the shoots are twisted, later the bush is restored).
More widely distributed in grape wood striation virus
- (longitudinal furrows and pits appear on the bark, the bark is thickened and loose, growth is stopped, and the bushes quickly die),grape red leaf virus
(the leaves become smaller, turn yellow, and then immediately turn red and fall off),Grape marbling virus, Vein necrosis virus, Grape vein mosaic virus.
Gives a clear pictureVine leafroll virus
- in the second half of summer, the leaves turn yellow or redden ahead of time - the strip along the central vein remains green. The leaves themselves thicken, become brittle and twisted, the crop does not ripen.
Control measures: bushes with signs of viral diseases are immediately uprooted. On the vacated place it is impossible to plant grapes for 5 years.
white rot
(white mouth, hail disease)
This fungal disease often occurs on damaged berries. sunburn or hail. The time of its appearance is when the berries reach from half the usual size to the softening stage, which corresponds to the time from mid-June to the end of August. At high temperature(from 18 to 30 C) and high humidity, the disease proceeds very quickly. In a matter of hours, the berries turn brown, acquire a scalded appearance and wrinkle.
root rot
Occurs in soils with excessive moisture. It is caused by a fungus that can exist on dead parts of the plant and, under certain conditions, switch to weakened grape specimens. In affected plants, white threads of the fungus appear between the bark and wood. Often they cover all the roots with a solid white mass. Sick bushes do not grow well, they have short internodes and yellow leaves. After 2-3 years from the onset of the disease, the plant dies completely. The disease can develop as secondary after the defeat of the roots by phylloxera. The tumors caused by the pest are destroyed and diseased tissues become infected with the fungus. root system dies off in 2-3 years.
Control measures: drainage device on damp areas, destruction of diseased plants, if the site is infected with phylloxera, then plant grapes grafted onto phylloxera-resistant rootstocks.
Diplodia
Grape necrosis
Fungal disease - affects ripening berries, shoots and wood. Affected berries acquire a black-bluish color, covered with black tubercles. The disease spreads when hot weather and prolonged rainfall coincide. The pathogen persists on plant debris.
Control measures: after the onset of the disease, carefully remove the affected parts from the bushes, after leaf fall, remove all residues from the site, treat the bushes with 1% Bordeaux liquid. If the vineyard is routinely treated against mildew, then the appearance of the disease is excluded.
This is a group of diseases with similar symptoms - the death of large areas of perennial wood. It may be of an infectious nature or caused by adverse conditions.
Spotted necrosis or dry arm - a disease of a fungal nature - infection occurs during the shelter of the vine with soil in winter. Brown spots appear on the vines, they grow, merge, as a result, the branches die off.
Vessel necrosis of wood - a disease of seedlings, causes darkening of the core and their death in the future.
Bacterial necrosis, Oleiron's disease, bacterial wilt - affects the entire aerial part. On perennial parts, black, deeply depressed spots appear with a brown border. In inflorescences, normal flowers alternate with blackened ones. Shoots in the nodes break and dry out. In spring, the lower buds do not germinate, while the upper buds produce wrinkled, chlorotic shoots. The causative agent is a bacterium. The disease can long years flow in an unexpressed form, and flare up in a cold spring. If an infection is suspected, the treatment is carried out before bud break with 5% Bordeaux liquid, after the leaves open 2 more times with 2%. Severely affected bushes must be uprooted.
Non-infectious necrosis can be caused by frost, deficiency of potassium, magnesium, the action of toxic smoke, and so on.
grape burns
Non-infectious damage to plant tissues caused by high temperature (41 C and above) and excessive solar radiation. The leaves turn yellow completely or partially. Damaged areas die off. Berries do not ripen. They acquire a red-brown color, wrinkle. Sugar does not accumulate. In areas where such damage is possible, you need to choose a formation where the clusters are covered with foliage. Sometimes you can untie the vertical growth and lay it along the bunches, that is, close the bunches from the direct sun. Keep the soil moist to help the plant withstand the heat.
Penicillosis
Penicillosis or Blue mold is a fungal disease of grapes. It starts as a small watery light brown spot. As it grows, the spot grows, slightly pressed, then covered with a greenish-gray, or olive coating. The berry acquires a moldy taste and smell. Appears on berries at the time of ripening. Most often in rainy and warm times, on plants damaged by mildew or pests.
Fusarium
Fungal disease of grapes. The first signs of the disease - yellowing of tissues between the veins of the upper leaves - appear 7-10 days before flowering. A short knot may appear on diseased shoots. The leaves are small, stepchildren appear in large numbers and they are thinned. This form of the disease is called cottis. Growth is markedly reduced. Leaves turn yellow in June. With the onset of hot weather, the green color may return. Berries on infected bushes are substandard - small, uncolored. The bush may die.
Outwardly, the bushes have signs of chlorosis caused by physiological causes. To clarify the diagnosis, it is necessary to make a cross section of thick branches, and preferably a bole - dead vessels will be visible on the cut, and the wood of the base of the bole and perennial wood will be painted pink.
The disease often develops in cold and wet springs.
With systematic processing of the vineyard Bordeaux mixture infection can be prevented. Top dressing with ammonium nitrate can sometimes improve the condition of the bushes.
Bacterial spotting
Bacterioses
E That whole group diseases caused by bacteria. Feature of these infections is the appearance of specific spots on leaves, ridges, stalks and berries. Bacterioses are widespread and can cause significant damage to the crop.
The disease on the berries begins with a small yellow spot in the depths of the tissue - this is the place where the pathogen penetrates. Then, in this place, a deepening quickly forms, which acquires a brown color. Infection occurs mainly through damaged skin - hail, sucking pests (most often cicadas ), or particles of flying soil or mowed weeds from row spacing during their processing. Some weeds may be involved in the spread and persistence of bacteria, such asfield loach
A characteristic difference between the defeat of bacteriosis and oidium is that during bacteriosis, the affected tissues sink deep into the berry, and when affected by oidium, they are squeezed out along with the seeds.
Within 10 days, the berries dry out and fall off. In the future, they will serve as a source of infection. The development of infection is possible from the beginning of flowering to the beginning of maturation. There is no cure. It is necessary to collect diseased berries and take them out of the site. According to some reports, treatment with Bordeaux mixture or ampicillin antibiotics can reduce the incidence rate. Prevention is possible with Fitolavin.
On stalks and ridges, the disease appears as brown necrotic spots on stalks and ridge ramifications. Diseased brushes quickly wither, flowers and berries fall off. Such infection is possible only during the flowering period. The causes of infection and control measures are the same.
Black spot (Phomopsis viticola Sacc., escoriosis, phomopsis, shoot death), a long-known fungal disease of the grape bush, was named after characteristics diseases on shoots and leaves.
The picture of the disease
Black spot is noticeable from June, primarily on the nodes of annual shoots of grapes in the form of black-brown to black, round or oval dots. Under a microscope, they look like swellings of bark tissue, on top of which a dead and browned stomata can be seen. Below it is a focus of necrotic cells in the form of a bag or lens. As the vegetation progresses, most of the dots increase, often merge into elongated spots that open in the middle and become light brown in the central part. The darker edges of the gap corky and give the affected areas a scab-like appearance. As a rule, only the first 6-7 internodes are affected. Often the lowest leaves are also infected, less often the tendrils and crests of bunches of grapes. Even flower caps are sometimes covered with black spots. On the affected leaf blades, oval and angularly outlined necroses are visible, mostly near a more powerful vein, which here is superficially or completely colored black. Leaf necrosis is surrounded by a light border of compacted tissue. Due to the tension of the tissue, curling of the leaf blade and, eventually, tears and holes are often observed. Severely affected leaves turn yellow prematurely. Ripening berries are sometimes also affected, turning dark purple and unpleasant in taste. In autumn and winter, the annual wood of grapes along the entire length, or only at individual internodes, or near the lower nodes, turns whitish-gray. On discolored areas of the bark at temperatures above 10 ° C, fruiting bodies of the fungus are formed, at the bases of which small black pustules are visible. Under the bark of perennial wood, fruiting bodies can also be found growing to free, cartilaginous black formations and sometimes overlapping each other. If the mycelium grows deep into the wood, then rotten areas are formed, which first weaken the growth, and later cause the death of entire sleeves.
The causative agent and the development of infection
In spring, at temperatures above 8 ° C and the presence of a water film over their excretory openings, pycnidia emit white and yellowish antennae, which can contain up to 1 million spores stuck together with each other. In rain or heavy dew, the masses of spores spread and spread partly with water droplets or, after drying, also by wind, insects and some mites. Phomopsis produces two types of spores: oval to spindle-shaped alpha spores with normally developing hyphae, and filamentous curved beta spores that form only rudimentary germ tubes; their functions are not yet known. The ratio of alpha and beta spores varies greatly. Some pycnidia contain spores of only one form or the other. If the spores fall on the green parts of the bush, they germinate already at a temperature above 1 ° C and a relative humidity of at least 86%, resulting in a new infection.
The spread of the fungus inside the grape bush can occur due to saprophyte growing mycelium, capable of starting growth at a temperature slightly above zero, and spores that are carried by rainwater from the pycnidia of fruitful shoots into the bark of the arms and trunk or into cracks and crevices in the wood.
Measures to combat black spot
chemical fight with the currently known active substances against the mycelium of the black spot fungus, which grows rapidly under the protection of the host tissues, does not give results. Therefore, it should be directed against the fruiting bodies of the fungus, and especially against scattered and spreading spores.
In case of severe damage, after a thorough cleansing pruning, timely winter spraying with DNOC, dinoseb or copper preparations is carried out, and the first two spraying agents are more effective. Winter treatment should be supplemented in the spring after the start of grape growth when the first leaf appears with treatment with one of the organic fungicides; the treatment is repeated when 2-3 leaves unfold, and then carried out every 10 days until the start of the fight against. We also recommend the last treatment as early as mid-August, at the same time also directed against grapes.
As a rule, with a weak defeat, it is enough to start the fight only at the beginning of spring growth. Since, apparently, it is impossible to completely eliminate black spotting in a short time even with repeated thorough winter and spring processing, should, at least, with a strong defeat, fight for several years.
Although economically satisfactory control of the disease is possible only with the help of fungicides, some supportive cultural practices are still of particular importance. These include: strict pruning of diseased vine shoots after leaf fall, using only healthy shoots as fruitful wood if possible, prompt burning of all shoots cut in the vineyard, exclusion of all infected wood from production planting material, careful conduct of green operations and balanced provision nutrients in the vineyard.
" Grape
Although grapes are an unpretentious culture, despite this, they require some care. One of these activities is the prevention and treatment of diseases. By breeding new grape varieties, breeders are working on this problem, however large-fruited varieties those with high sugar content are still prone to all sorts of diseases. To receive annually high yield the grower needs to be aware of the danger and be able to deal with it correctly and know what to do.
The most common and common diseases of this crop are:
- mildew;
- alternariosis;
- cercosporosis;
- armillariasis;
- oidium;
- chlorosis;
- rubella leaves;
- septoria;
- escoriosis.
Mildew and his treatment
The second and more common name for the disease is downy mildew. This disease is very dangerous not only for the grape bush, it can affect short time the entire vineyard. At the initial stage, it manifests itself in the form of light yellow-oil spots, the size of a penny coin on young foliage. On older leaves, the spots are angular and parallel to the veins.
With further development, a mycelium appears in the form of a white fluffy coating on the back of the leaf. If the weather is warm with high air humidity, the fungal infection rapidly spreads to the tops of young shoots, mustaches, affects inflorescences and recently set fruits.
This type of fungal disease is formed in the summer period in the leaf plates, where it survives the winter well.
Fungus spores are activated at a temperature of +10 degrees. The most favorable conditions for instantaneous spread are an increase in air temperature from +20 to +27 degrees and humidity for 3 to 5 hours. However, at a temperature of +8, and above + 30 degrees, the fungal infection does not spread, since the spores do not germinate.
Vine leaf affected by downy mildew or mildew The most dangerous periods for the spread of infection are:
- May 20-June 13;
- June 23-30;
- July 15-August 7.
In order to avoid infection, you must:
- the right choice of site for growing grapes;
- autumn mulching between rows;
- correct formation of the vine to ensure good breathability;
- timely pruning of excess shoots;
- removal of weeds under bushes and between rows;
- drainage or drip irrigation;
- top dressing with mineral fertilizers;
- starting from the spring, prophylactic treatment with Bordeaux mixture every 10 days.
Alternariosis disease
Alternariosis, or olive blotch, affects the leaves of grapes as a result of high humidity. It appears in the form of spots on the back and an olive-gray coating. With the active development of the fungus, the leaves dry out, curl.
This type of fungal disease also affects the fruits. When they are stored, the fungal infection spreads to healthy brushes, affecting them. On fruits, the fungus manifests itself in the form of cracking and changes in the taste of berries. The shoots affected by a fungal infection do not mature and do not tolerate wintering. The spores of the fungus overwinter on infected shoots, fruits and in upper layers soil.
Alternaria on vine leaves The necessary preventive measures are:
- timely pruning of infected processes;
- removal and burning of weeds and dry leaves;
- feeding;
- treatment blue vitriol and Bordeaux mixture.
The beginning of the defeat of Alternariosis of grape berries Terms of preventive measures:
- During from March 21 to April 12 after tying the vines, spray with copper-containing preparations.
- April 24 to May 9 treat with a biofungicide. You can use the drug "Trichofit" for these purposes.
- May 16 to June 1 treat with the drug "Kvadris". Continue processing every 14 days until the initial stage of berry ripening.
- From August 15 to September, after harvesting, prune the vine and burn it.
- From October 20 to November 10 it is necessary to rake out the fallen leaves and treat the soil and the vine with copper-containing preparations.
It should be treated with sprayers from the bottom side. When processing the top surface of the sheet, there will be no results.
Cercosporosis and how to deal with it
This fungal disease affects leaves, shoots, stalks and fruits. First of all, foliage that is close to the ground is affected, since the sun's rays do not penetrate well into this part of the bush, and increased humidity is observed under the bushes. The most rapid development of this disease occurs at an air temperature of +30 degrees. If the temperature rises to + 40 degrees, the fungus stops growing. On a direct hit sun rays fungus dies.
With a strong defeat by the fungus, grape bushes do not bear fruit well, the taste of the fruit deteriorates, and the vine does not reach maturity.
It appears as an olive coating on the lower part of the leaves. Over time, brown spots appear on the surface of the leaf, with a light touch, the leaves fall off.
Affected berries are covered with an easily washable olive coating, become hardened and fall off when touched.
Preventive measures necessary to prevent the disease:
- mandatory pruning of grapes twice per season;
- deep digging between rows in spring and autumn;
- watering 4 times per season;
- weed removal;
- spraying bushes in autumn and spring with a 1% solution of Bordeaux mixture;
- mandatory support.
- spray infected bushes every two weeks with fungicides;
- burn infected leaves.
Armillariasis affecting the roots
This disease is a fungal infection that develops on the roots of a plant. The infection infects the roots of grapes, penetrating the bark and releasing toxic substances, killing living tissues, after which it develops on infected cells. Spread by fungal spores. The spores are extremely toxic and can kill an infected plant. Typically, infection occurs in spring period, and in autumn yellow mushrooms grow on the bush.
For the development of this disease, there must be increased humidity and air temperature from +15 to 26 degrees. To prevent the spread of the disease, it is necessary to uproot the infected bush, treat the soil with special fungicides and not plant new seedlings in this place for a year.
In order to prevent infection of the vineyard with armillariasis, it is necessary to separate the bushes growing along the forest belt with a ditch.
aspergillus rot
With this disease, grapes are affected. A distinctive feature of this disease is its rapid development at high air temperatures - above +31 degrees.
The first symptoms of the appearance of Aspergillus rot on grapes. Remove diseased berries At the initial stage, a berry affected by another fungal disease becomes a beneficial breeding ground for the Drosophila fly.
First, a little noticeable white coating appears on the berries, then dark depressed spots. The skin in these places is pulled together and cracked. The pulp of the berry rots due to the presence of Drosophila fly larvae. On the surface of cracks, plaque initially has White color, then darkens and turns into a dark powdery mass.
Measures to combat this disease are:
- destruction of residues with spores of the fungus;
- timely harvest.
If the recommendations are not followed, Aspergillus rot instantly spreads throughout the bunch oidium or powdery mildew
Fungal disease has a second name - powdery mildew. It affects the green mass of the bush, the shoots of the inflorescence. When affected, the inflorescences do not develop and do not ripen. This disease lives and progresses only on living cells. Winters in bark cracks and on buds.
Spores, falling on the leaves, multiply rapidly, carried by the wind. Exceptional conditions are high humidity (more than 80%). Depending on the temperature regime, the incubation period lasts from a week to two weeks. A favorable temperature for the rapid development of the disease is a temperature of +20 degrees.
Signs of infection:
- white bloom on both sides of the sheet;
- the edge of the leaves is curved, yellow;
- the plaque that appeared on the clusters and flowers resembles flour;
- shoots are covered with dark spots;
- dead areas appear on the processes.
Prevention measures are as follows:
- digging the soil, cleaning foliage and weeds;
- top dressing with phosphorus-potassium fertilizers;
- processing with Topaz;
- timely pruning of bushes in order to prevent thickening of the vineyard;
- tool processing after trimming;
- accurate watering without hitting the bushes;
- water-10 liters;
- sulfur-100 grams.
With this solution, it is necessary to process the bushes in the evening.
Oidium on grapes. The disease does not allow clusters to develop. Chlorosis and measures to combat it
Chlorosis occurs when there is a lack of iron. The plant does not produce photosynthesis, as a result of which the development of the bush stops and the yield decreases. It manifests itself in the form of spots on sheets of bright lemon color. The shoots stop developing, and the leaves dry up and fall off. The fruits become small and do not reach maturity. A weakened bush may not survive the winter.
Prevention of this disease is the treatment of bushes with the drug "Chelate".
Grape leaves affected by chlorosis acquire a rich lemon hue rubella leaf
In late spring or early summer, grape bushes can become infected with this fungal disease. It affects grape leaves damaged by insects.
It is possible to determine the infection of a bush with rubella by the following signs:
- sheets in the lesions have spots in the form maple leaf covered with a rusty coating;
- before the beginning of the flowering period, infected leaves fall off;
- in white grape varieties leaves are covered with light yellow spots, gradually darkening, outlined by a yellow border;
- in dark varieties, the spots are bright red.
To avoid infection you need:
- process the leaves with a Bordeaux mixture;
- carry out regular pruning of bushes;
- rake and burn fallen leaves;
- apply fertilizer to the soil;
- dig aisles.
Septoria
Typical for Muscat grape varieties. It appears as small brown spots on the sheets. If the humidity is high, mold will form on the underside of the leaves. When it dries, it falls off and spreads spores of the fungus.
To prevent the spread of the disease, it is necessary to remove fallen leaves and damaged plants.
As a preventive measure, it is necessary to treat with a 1% solution of Bordeaux mixture.
Leaves affected by septoria begin to grow moldy and dry out Escoriosis disease
Escoriosis is a dangerous fungal disease that affects all parts of the plant. Represents black spots on the leaves and shoots of the bush. Spread most rapidly in cool weather with high humidity. Affected bushes become weak, while their frost resistance decreases.
To combat this disease, the drug DNOC is used. During the growing season of plants, treatment with Bordeaux mixture can be applied.
With severe damage to the bushes after autumn pruning, dried sleeves are removed and the bushes are carefully treated with copper-containing preparations.
Preventive measures:
- mandatory application of fertilizers containing zinc and boron;
- timely formation of a bush;
- removal and burning of affected parts;
- using healthy seedlings for planting.
To protect the vineyard from diseases, it is necessary to observe the conditions for growing grapes and take timely preventive measures to prevent the spread of infections. It is recommended to plant those varieties that are most suitable for growing in this region.
Many are fans of delicious grape berries, which is why they try to plant this crop near their own homes or in summer cottages.
However, not always and not everyone manages to achieve good results in viticulture. Indeed, along with the existence of a huge number of grape varieties, there are also a large number of its diseases, as well as pests that can harm the grape bush.
But still, if we take into account the possibility of damage to grapes by diseases or notice their appearance in time, it can be effectively dealt with.
It is in particular the diseases of the vineyards that we will devote you below.
Oidium: how to recognize and deal with this disease
What you need to know about oidium?
This disease is often referred to as "powdery mildew" because one of its manifestations is whitish dust on vine leaves. Refers to fungal diseases, it came to our open spaces from the North American continent. It is very dangerous because affects both the grape bush and the crop. The degree and characteristics of the damage will depend on the grape variety.
External signs of damage to the grape bush by oidium
When a grape bush is affected by this disease, many shoots will lag behind in growth, and the leaves on such shoots will be curly. Dust of a gray-white shade is especially noticeable on the leaves. With the beginning of the tying of the crop, this dust will be noticeable on the entire surface of the affected leaves, inflorescences and clusters. Affected by oidium inflorescences and already set berries die off and dry out.
It is important to note that the incubation period during which oidium can infect grapes lasts 1-2 weeks. Warm and humid weather has a positive effect on its reproduction and distribution. Even at temperatures above 5ºС, this fungus begins to germinate.
What to do so that the bush is not struck by powdery mildew
With oidium, even simple agricultural practices help to fight well. In particular, powdery mildew is afraid of a large amount fresh air, reproduces less when thinning a thickened bush.
Also, preventive spraying is recommended for grapes, which should be carried out three times per season: when shoots grow on the vine to a length of 15-20 centimeters, before flowering begins and during the period when peas appear on clusters.
Methods for treating a grape bush from oidium
For the treatment and prevention of this disease, it is recommended to use special drugs. Among them, the most effective and common are Strobe, Thanos, Topaz, Horus. Diseased leaves, shoots and clusters are recommended to be removed and burned. This will help stop the further spread of the disease.
Downy mildew or mildew is the most dangerous disease of vineyards.
What is the peculiarity of this disease?
Unfortunately, mildew is not only very dangerous, but also the most common disease that affects vineyards. Just like true powdery mildew, mildew can affect absolutely the entire bush. Of course, the degree of damage to this disease is not always the same.
The grape variety and weather conditions will play an important role: the disease spreads best with heavy rainfall and high humidity.
How to recognize mildew on your grapes?
Mildew appears as round, as if oily, spots that appear on growing vine leaves. At high humidity, white powder appears under such a spot on the underside of the sheet - a powdery coating. Over time, the places of the leaf affected by such spots begin to die off: the leaf turns yellow, and then the place of the “burn” acquires a red-brown hue.
Such leaves fall. But the lesion is not limited to leaves, but can pass to inflorescences, on the crest of which long green spots appear. The affected tissue of the ridge also dies off over time, disrupting the supply of necessary substances directly to the berries.
Mildew can also affect the entire bunch, covering it with white powder and causing the berries to dry out. This disease is especially dangerous for the reason that without special spraying and under favorable conditions, in one season, mildew fungus able to regenerate up to 16 times.
In order for mildew not to affect your grapes, it is very important to take good care of them and select varieties with complex resistance.
In order for the grape bush to be strong and strong, it is regularly needed fertilize capable of nourishing the soil with potassium and phosphorus. It is also important to constantly mulch the soil near the trunk and remove all stepchildren from the vine.
But the best prevention of mildew will be treatment of the bush with various fungicides. Preventive treatments are carried out at the same time as spraying from true powdery mildew.
Treatment of a grape bush affected by mildew
So that the disease does not spread and in order to remove the source of its occurrence, it is recommended to remove and burn the affected areas of the grape bush. Also, for planting grapes, it is better to choose places where the bush can receive the maximum amount of solar heat and light, even under the worst conditions. weather conditions.
Effectively deal with mildew you can use the following medications:
- "Antrakol"
- A mixture of "Bordeaux liquid"
- "Kuproskat"
- "Ridomil"
- "Strobe"
- "Copper chloride"
How to help grapes resist "black spot"?
Distinctive features diseases
Another very dangerous fungal disease for the grape bush. When describing it, names such as phomopsis or simply the death of shoots are often used. It is often found precisely in those vineyards that grow in areas with high air humidity. Black spotting appears mostly on all green parts of the bush and on the stiff vine.
Features of the manifestation of black spot in the vineyard
On the indicated parts of the grape bush, discoloration begins. Typically, this kind of spots affect only 6-7 internodes, although there are cases of damage to the entire bush up to the trunk. After fading and at temperatures above 10ºС, black dots appear on the affected areas - the bodies of the fungus or pycnidia.
If the disease manages to penetrate deep into the wood, the affected area rots and can cause the death of the entire area of the grape bush.
Black spotting begins to appear from June, hitting annual shoots with peculiar round dots, painted in black-brown color.
With the growth of the shoot, these points spread and stretch, causing cracking of the vine. Sometimes the defeat of black spot affects the leaves and ridges of the clusters. Affected leaves begin to turn red and turn yellow long before autumn.
Preventive measures to help prevent black spot damage
It is very important to know that vineyards are affected by this disease, often through damage to the bush. So, with untimely pruning or inaccurate removal of shoots, injured areas become especially vulnerable.
In combination with unfavorable weather conditions, there are all conditions for infection of grapes with black spot. That's why, pruning should not be considered a pure formality, it is worth treating this process with the necessary responsibility and processing the places of cuts.
For the prevention of black spot, those drugs that are recommended for the treatment and prevention of mildew are well suited.
How to overcome black spot in your vineyard?
Chemical methods of combating the manifestations of this disease have not yet given good results. It is very important to remove the fungus itself, for which autumn time after pruning the vineyard, it is treated with copper preparations.
All damaged areas of the vineyard are cut out completely.
Spraying against black spot is carried out and in early spring, with the appearance on the bush of the first 2-3 leaves. For such spraying, fungicides are best suited. After that, it is worth spraying the bush about 3 more times with special preparations, combining the treatment with spraying from oidium and mildew.
The danger of black spot is that it the disease is considered chronic for vineyards. Therefore, if it has already appeared on the bush, then it will take more than one year to fight it. However, if you put in enough effort and carry out regular treatments, you can significantly improve the bush.
How to distinguish manifestations of gray rot on grapes?
If in the future the air around the grape bush stagnates, and there is an excess of moisture in the air, a gray coating can even cover the clusters. At the same time, if you touch the affected bunch, it will dust.
Thus, the disease completely spoils the crop. if the weather is dry, then only a few berries can be affected, which wrinkle over time. If gray rot struck the inflorescences - in dry weather they simply die and dry up, acquiring a brownish color.
This disease can cause rotting of berries and bunches of grapes.
Prevention of gray rot: what activities are important to carry out?
- In general terms, the prevention of gray rot is the same as that of oidium or mildew: the same preparations are used and with the regular performance of the necessary spraying, the disease often does not manifest itself.
- In order not to cause the appearance of gray rot on your own, it is worth considering whether this disease affects primarily the places of cuts and those places that have been weakened. Thus, you need to be attentive to the bush and keep a good eye on such places.
- The grape bush becomes more susceptible to gray rot if it is only one-sidedly fed with nitrogen fertilizers.
- It is also worth knowing that even if spring time gray rot and hit your grapes, then when dry summer weather sets in, it will not spread further.
Treatment of a grape bush for this disease
In order for the disease not to spread throughout the bush, it is important remove the affected parts of the grape. Also, in this case, spraying with special preparations will be mandatory. Even if the drugs do not destroy the disease, it will not develop further this season.
Anthracnose: features of the defeat of the grape bush and the fight against the disease
Characteristics of the anthracnose disease: why is it dangerous for grapes?
Anthracnose, like almost all fungal diseases, often has a very extensive affected area. It manifests itself both on the leaves and shoots of the vineyard, and on the inflorescences, and later on the berries.
The disease is found all over the world, especially favorable for it is a warm climate, as on the Black Sea coast and southern Ukraine.
The most negative feature of this disease is its ability to hibernate and last up to 5 years. Thus, even without external manifestations, grapes can be affected by anthracnose. It is worth noting that in one growing season, the fungus of this disease can produce about 30 generations of its spores.
This disease is especially dangerous for only blossoming parts of the bush, if at the same time the weather is generous with precipitation.
Features of the manifestation of anthracnose grapes
Leaves affected by this disease are distinguished by the presence of brown spots on them with a characteristic dark white border. Due to this nature of the manifestation, this disease is often called "bird's eye".
The spots can often even merge. As with oidium, these spots cause the death of leaf tissues. Shoots also affect the heel of a pink-gray or brown-brown hue., which look like depressed pits.
On the shoots, the spots are also characterized by a dark border. Affected wood cracks over time, ulcers form on the vine. Shoots can generally crack, and later completely dry out. In the same way they react to anthracnose of grapes and petioles of leaves and crests of clusters.
Inflorescences after the defeat of the described disease become brown, dry out. The berries are also affected by depressed reddish spots, with an obligatory border of a darker color. The disease can deprive the crop and greatly harm the bush.
What to apply for the prevention of anthracnose grapes?
This disease is especially widespread in rainy weather. Therefore, after the weather becomes drier, the grape bush must be treated with preparations.
It is best to use fungicides that need to be sprayed on the bush twice before flowering, and once after, during the formation of grape berries.
It is best to select grape varieties that genetically have good resistance to anthracnose.
Treatment of a grape bush affected by anthracnose
It is quite difficult to treat this disease, although it is possible to achieve success. As preparations for treating the bush, the following are used:
- "Antrakol"
- "Acrobat"
- A mixture of "Bordeaux liquid"
- "Kuprosat"
- "Ridomil"
- Thanos
- "Horus"
It is important to note that the treatment is carried out both by contact (the very first treatment in the spring; copper preparations are used) and systemically (all subsequent ones).
Was this article helpful?
Thank you for your opinion!
Write in the comments what questions you did not receive an answer to, we will definitely respond!
You can recommend the article to your friends!
You can recommend the article to your friends!
94
times already
helped
Grape diseases affect the quality of the crop. The causes of the occurrence can be poor care of the bushes, timely failure to prevent pests, excessive watering.
In order to prevent the spread of diseases and pests in the vineyard, it is necessary to know their main signs in order to quickly identify and combat pathology. This is exactly what our article will help the grower to understand.
Common diseases
Diseases of grapes are conditionally divided into two types:
- Infectious. Infection of bushes occurs with harmful microorganisms. The threat to grapes is that fungi, viruses, bacteria are transmitted through air, water, pegs, garden tools. On the bushes, part or even the entire crop is lost. In addition, the vine does not have time to mature, so the next year you should not expect a good yield from the vineyard. It's in best case. If you do not process infected bushes, then you can lose whole bushes.
- Non-infectious. May appear as a result of improper pruning, mechanical damage to the vine, adverse environmental conditions.
Scheme of the development of infectious diseases.
In order not to provoke the appearance of non-communicable diseases, pruning and all other operations should be carried out very carefully, with a sharp pruner.
bacterial cancer
The cause of the disease is a rod-shaped bacterium. White growths of various sizes and shapes appear on the vine. Then they darken and gradually become hard. These parts dry out, and the disease can lead to the death of the whole bush. Most often manifested in the middle of the growing season of plants. During this period, it grows very large and can be up to 20 cm in diameter.
Cause of occurrence: bacterial cancer- result mechanical damage and further damage to the damaged areas by frost. More often this disease occurs in vineyards in the central regions of the country and less often in the south. Therefore, it is important to know how to do it right. 
Cutting and trimming should be done with great care. This will reduce the risk of bacterial cancer.
black rot
The spores of the fungus are black, hence the name of the disease. The microorganism hibernates in the soil, under the leaves, bark perennial shoots. Therefore, infection can constantly occur.
A fungal disease affects the entire bush, but, above all, the berries. They are painted in blue, blue or purple. The berries become soft, then begin to shrivel, then blacken and crumble. Rounded or slightly angular spots appear on the leaves, dotted with small black tubercles. The disease spreads very quickly in wet and cool weather. The whole bunch is affected.
Black rot affects all herbaceous parts of the plant, causing the greatest damage to fruits.
If such an unfavorable period does not last long, then only individual berries are deformed, and the whole bunch ripens normally.
white bloom
The causes of white bloom on the grape bush may be mildew or oidium. But it is possible that this is another fungal disease - white rot. It differs from black rot in that it affects not individual berries, but the entire bunch. The berries become lethargic, wrinkled. Their color changes. They acquire a reddish-brown, brown color. And then they dry up. Leaves are rarely affected. They dry up, but do not fall off the bush.
If a period of prolonged rains passes, then a dirty-white coating appears on the infected berries. This is the result of the fruiting of the fungus.
If you do not notice and stop the spread of plaque in time, then the fruitful vine may die.
The most common cause of the disease is the defeat of vineyards by hail.
Blackleg
Strong browning of the roots can be observed in such cases:
- Blackleg. Refers to fungal diseases. Affects seedlings of vegetable crops. Grafted grape seedlings or own-rooted ones, if planted in contaminated soil, may suffer from this. The shoot at the bottom near the root turns black and softens;
- If the roots are damaged by frost from freezing of the upper layer of soil, a continuous browning of the roots occurs, which subsequently becomes black. These signs appear in the spring;
- Black spotting. It can affect all parts of the plant. At the end of the flowering of grapes, and this is somewhere in May or June, small black spots appear on the plant.
The “black leg” appears in conditions of high humidity, on flooded and weakened seedlings, so it is important to observe temperature regime and watering.
Mildew
The basis for protecting grapes from diseases is the timely processing of the plant.
Spraying will be effective only if it is carried out in the evening in calm weather. Fungicides and other drugs are used to treat diseases and destroy pests.
Fungicides
Fungicides - used to eliminate fungal diseases. According to their effect on plants, they are divided into three groups:
- Systemic. Through leaf blade are able to penetrate the stems and, thanks to sap flow, spread throughout all the vegetative organs of the bush (Topaz, Skor, Quadris, etc.). They are not washed off by rain, which allows you to do only three treatments per season;
- Contact. Influence directly on the lesion (Shavit, Kuprozan);
You can use to fight systemic fungicides intended for different cultures: "Karbil Top", "RidomilGold". Or use Bordeaux mixture.
The disadvantage of these preparations is that after each rain it is necessary to carry out processing. There may be 6-7 of them per season.
- Complex. The most effective, as they combine the properties of contact and systemic preparations (Paracelsus, Polihom, etc.).
Paracelsus has a contact, systemic effect, which compares favorably with other drugs.
Preparations
Pests and diseases can destroy not only the crop, but also entire vineyards. Therefore, in addition to fungicides, contact-protective preparations are used:
- Bordeaux liquid. The concentration varies. So for preventive purposes or with a weak development of the disease, a 1% solution is used, and with strong development the fungus is already 3%. They begin to spray at an air temperature of 11-12 degrees and regularly repeat this operation after each rain;
"Bordeaux mixture" is a remedy for protecting fruit, vegetable, berry and other plants from diseases
Treatment with Bordeaux liquid is not allowed 15 days before the start of the harvest.
- copper oxychloride (Kupritox. Hom). Effective against mildew, low toxicity. Processing is carried out at least 6 times during the growing season;
- colloidal sulfur. Apply against ticks, oidium. It is the lower part of the sheet plate that is carefully processed.
Prevention measures
Any grape variety requires. Even resistant against fungal diseases. Because pests and diseases in some years under adverse environmental conditions, and this very coldy, hail, drought and others cause great damage to grapes. On average, the yield is reduced by a quarter. In addition, the marketable appearance of berries is deteriorating, the growth of shoots is weakened, and they do not ripen well. Sick bushes the next year give a smaller crop. And if the defeat by diseases and pests was large, then the bush may die. Therefore, they try to prevent the onset and development of the disease. For the prevention of diseases of fungal etiology, Ridomil Gol, iron and copper sulfate are used.
inkstone
It has two positive features:
- Low toxic substance for the human body.
- Has a wide spectrum of activity: fights pests, restores the structure of affected wood, protects vineyards from fungal diseases. Such as mildew, oidium, anthracnose, etc. As a result, the yield of the bush increases. The bunch grows large, and the berries are juicy.
start preventive treatments spring before bud break. The second time you can carry out preventive spraying at the end of the growing season. This must be done in the fall. They process not only the bush, but also the soil near the plants with a solution of 500 grams iron sulphate in 15 liters of water.
The treatment of grape bushes with iron sulphate is carried out in the spring, before the buds form.
Processing of grapes must be carried out, taking into account certain safety measures, even if the packaging with the drug contains a note that it is of low toxicity to humans.
Disease resistant varieties
Recently, hybrids resistant to certain diseases have appeared. At the same time, it can be high resistance to mildew, but susceptibility to anthracnose. Much still depends on the climatic parameters of the growing area, the soil, the condition of the seedlings. So on south coast Crimean grapes are affected by mildew not every year, unlike regions located at the same latitude. Therefore, the reduced susceptibility of some varieties to diseases does not mean that it is not necessary to carry out preventive treatments.
These varieties include:
- ; If there are just such signs on the berries, then it is better not to use them, since this is a fungal disease. True, such berries do not ripen. Therefore, they do not reach the consumer's table. But it happens that small black dots are visible on the grapes. At the same time, the bunch is beautiful, and the berries are juicy with a characteristic color for the variety. Such grapes can be eaten. It will not bring any harm to the body.
Video
In this, they teach to recognize grape diseases at the very beginning and learn to fight them.
conclusions
Part of the crop and bushes can spoil diseases and pests. At the same time, the shoots do not ripen, the bush weakens and the next year's harvest will be low. If the defeat is severe, then the landings may die. Among the most common diseases and pests:
- Diseases: Mildew, oidium, anthracnose, cancer. Gray, white, black rot and others. Cancer
- Pests: Phylloxera, wireworm, winter scoop, marble and hairy beetle, spider mite, etc.
- For the fight with diseases use phytoncides. Even for resistant varieties preventive treatments are needed. Especially in adverse weather conditions. This can be done with Ridomil Gold, Bordeaux liquid and iron sulfate. The use of iron sulfate for processing apple trees is described. This scheme can be applied to grape bushes.
