Diseases of grapes on the leaves. Major diseases of vine leaves
Everyone loves grapes. Its deep purple, green or yellow berries, poured with juice, warmed by the summer sun and washed by warm rains, seem to be asking for a mouthful. But to get this beauty and deliciousness, the grower must sweat a lot. Especially a lot of energy is taken away by diseases of grapes and the fight against them. Unfortunately, there are no varieties that do not suffer from any infection at all. If a variety is advertised as being disease-resistant, it means that diseases on the bush will appear later than on ordinary ones and may not affect all bunches. Diseases and pests of grapes, of which there are several dozen, spoil the appearance of plants, destroy the crop. Our task is to prevent their appearance and successfully fight when detected.
Pests
Despite the fact that diseases and pests of grapes are so numerous, it is not very difficult to fight them. The development cycle of insects is such that they necessarily lay eggs. Most do this on the underside of the sheet. Fight hatched caterpillars and larvae with easy contact insecticides. Spraying is carried out according to indications. If goldsmiths and woodworms are found, you need to carefully examine the bush and remove all damaged shoots, and after that, treat it with the drug. You also need to weed the grape plantings, remove all dry fruits and leaves from the bushes.
Bacterial diseases
As the name suggests, this group of diseases is caused by bacteria. They penetrate into the body of the plant through wounds from mechanical damage (for example, when pruning, grafting), and also "thanks" to the efforts of sap-sucking insects. The most dangerous disease of this nature - bacterial cancer. Its pathogen lives in almost all types of soil. Once in the plant, it introduces its DNA into the "victim" cell, after which it begins to divide at a breakneck speed, which is manifested by growths on the vines. There is no cure for this infection. The best thing to do is to remove and burn the diseased plant. Take from him planting materialincluding seeds is not allowed. Also, you cannot plant a new plant in its place for 3 years.
Apoplexy
This is another bacterial disease that cannot be cured. It manifests itself suddenly and very rapid decay a whole grape bush. Caused by bacteria that produce toxins that poison grapes.
Since cure bacterial diseases it is impossible, protection of grapes from diseases of this type is carried out by prevention. It consists in proper care, taking precautions when buying new seedlings and mandatory fertilization of the grapes so that the bushes grow strong and viable.
Fungal lesions
Mildew
This infection is also called downy mildew. Initially, only young shoots and leaves are affected, later the fungus captures inflorescences and berries.
As a result, the whole bush suffers from mildew. There are various diseases of grapes and the fight against them, but mildew is considered the most dangerous. At the initial stage, it appears lighter than the entire leaf plate in spots. The fungus continues to develop and soon the spots turn gray-brown, and a gray bloom appears on the underside of the leaf. These are new spores, ready to spread further through the vineyard with the lightest breeze or a drop of moisture. Shoots are affected in the same way as leaves. Diseased inflorescences and ovaries darken and dry out. If the fungus has hit the inflorescence petiole, the whole bunch dries up and disappears. It hibernates with mildew in soil and on leaves. To reduce the risk of this disease, preventive measures must be included in the care of grapes - cleaning fallen leaves and spraying the soil around the bush with fungicides. Spraying grapes against mildew is carried out with Bordeaux liquid, which is prepared independently from copper sulfate and quicklime. You can also use "Ridomil", "Acidan", "Mancozeb", "Rapid Gold" and other drugs. Spraying begins when the air temperature reaches +10, young shoots have grown by 10 cm, passed good rain or when light green spots appear on the leaves. Further treatments are carried out every 7-14 days.
Grape disease oidium
This infection is also called powdery mildew... It can begin at any stage of plant development and affect any part of it or all at once. The oidium fungus overwinters in the bark and buds of grapes. It manifests itself as a dirty white fluffy bloom on leaves, shoots, berries.
At the same time, the leaf blades turn yellow, the flowers and young ovaries dry out, and if the disease began in the ripening phase of berries, cracks appear on them, from which the seeds stick out. Warm winters and rainy springs are most favorable for oidium. Then there are real epidemics of this infection. To prevent mildew grape disease, the first treatment is carried out in early March, especially if the weather is favorable for the fungus. Further according to indications. Preparations against powdery mildew: ground and colloidal sulfur, copper oxychloride, "Topaz", "Bayleton", "Tiovit Jet".
Alternaria
Anthracnose
Diseases of grapes and their treatment depend on various reasons. Anthracnose, for example, is actively manifested at high humidity, regardless of the air temperature. Especially if the grapes are damaged by hail. First, the infection appears on young leaves and shoots and manifests itself as dry spots, in the place of which holes appear later. Their edges are black. The leaf either dries up or bends. Cracks appear on the affected shoots (sometimes to the very center). On the affected berries, the disease manifests itself various shapes spots of gray or dark color with an even darker border. Later, the berries crack and the brushes may dry out completely.
The mushroom hibernates in infected branches and in dried, but not fallen off fruits. Therefore, caring for grapes in order to prevent anthracnose includes autumn pruning and removal of all mummified fruits from the bushes. Spraying is carried out with fungicides "Skor", "Acrobat", "Ridomil", "Arcerid". They start when young shoots grow up to 10 cm.
Gray rot
It is important to correctly recognize grape diseases and start their treatment on time, because many fungi, having begun to multiply in any one part of the plant, soon capture it entirely. This refers to gray rot, which affects absolutely all parts of the grapes. The fungus also overwinters in all parts of the plant. Comes to life at positive temperatures. Damp cool weather is especially favorable for the mushroom. In the heat, you can even make wine from the affected berries. It is manifested by the browning of the infected parts of the plant and their death. The berries will rot but may remain in the brush. Treatment against the fungus is carried out with "Fundazol", "Eupparen", as well as iodine solution.
White rot
This infection refers to grape berry disease. The fungus can affect the entire cluster or only a few fruits. The disease begins during the ripening of the grapes and is manifested by browning and wrinkling of the berries. Dirty pink spots (no rain) and black spots (with high humidity) become noticeable on them. Sometimes white rot affects the shoots, forming light spots with a dark rim on them. Such shoots die off. Fight white rot by mechanical destruction of affected grape clusters and spraying. Preparations "Funzodol", "Kolfugo Super". After hail, such treatment must be carried out immediately, otherwise the fungus will invade the plant's body. In addition to gray and white, there are also root, black, vinegar and blue rot. The root appears with improper watering and damage to the roots. Acetic acid is carried by fruit flies and manifests itself in rotting ripe berries... Blue rot or penicillosis develops on berries already infected with mildew.
Which leaf diseases affect grapes
It must be said that there are very few diseases affecting only leaves. As a rule, starting on the green parts of the grapes, the infection soon captures the berries. Chlorosis (cessation of chlorophyll production) can be attributed to purely leafy ones. It is manifested by the fading of the leaf plate. The reasons are the lack of iron or zinc in the soil with a high copper content. The bush first sheds faded leaves, then clusters and, in the end, may die. There is also viral chlorosis or yellow mosaic, carbonate and edaphic (with strong soil salinity, liming, waterlogging). In addition, grapes are affected by leaf disease septoria (it appears on old leaves with dark spots, the protection is the same as against mildew) and fusarium (signs are similar to chlorosis, diagnosed on a cross section of branches, on which pink fragments should be visible). Another sign is too small leaves and fruits, as well as multiple painful-looking stepsons. Control measures - spraying with Bordeaux mixture and regular feeding.
Spot or bacteriosis
These grape diseases and their treatment are complex and not always effective. They are caused by bacteria (leaves, berries, shoots are affected) and are manifested in the appearance of various kinds of spots. On berries, the disease begins with small spots, dots, which quickly increase and darken. Bacteriosis spots differ from oidium in that they sink into the berry. The crop can die within 2 weeks. There is no effective treatment yet, but gardeners save the grapes with Bordeaux liquid and antibiotics, and for prophylactic purposes they are treated with Fitolavin. At the first sign of illness, it is necessary to destroy all diseased clusters and parts of the plant.
In addition to bacterial and fungal, there are viral diseases of grapes. Viruses are transferred from a diseased plant to a healthy one. They manifest themselves in different ways. The most characteristic are curly foliage and its other deformations, mosaic spots on leaf plates of yellow, black, red and other colors, lagging bushes in growth, grinding berries to the size of peas. Control measures have not yet been developed.
Reference:Not all grape diseases are treatable: for some (bacterial cancer), only a radical method is applicable - stubbing with subsequent quarantine.
- Viral diseases of grapes.
- Short node (infectious degeneration).
- Edging of veins.
- White mosaic (panache, variegation)
- Interveinal chlorosis.
- Golden yellowing.
- Flattened trunk.
- Shoot necrosis.
- Mosaic virus of razuha, or Arabis mosaic.
- Asteroid (star) mosaic.
- Virus of furrowing of wood of grapes.
- Red leaf virus.
- Leaf marbling virus.
- Vein necrosis virus.
- Leaf roll virus (golden yellowing).
Reference:Only the first 4 positions are scientifically described in the list "Viral diseases of grapes". The rest of the viruses were isolated, but, according to the results of observations, are presented in grapevine in latent form.
Non-communicable diseases
Diseases provoked by growing conditions.
- Elementoses (diseases associated with a lack of nutrients):
- chlorosis (lack of iron, zinc, manganese or boron);
- rubella (lack of potassium);
- drying of the ridge;
- Burns of grapes.
- Sprinkling berries.
- Wood vessel necrosis.
- Paralysis of the ridges.
- Apoplexy of the trunk.
Reference: From the practical experience of domestic amateur gardeners, it follows that from the above list, only a part of grape diseases is generally known: mildew, oidium, anthracosis, chlorosis, rubella, bacterial cancer and elementose.
Photo
How to determine the type of lesion?
The first clue is given by the slightest deviations from the norm in the appearance of the plant, revealed during visual inspection at any stage of growth. Information about the appearance of an infectious disease in a neighboring area should also alert the gardener. Analysis of unfavorable weather situations in winter-spring is also able to reveal the likelihood of an infectious lesion of the bush.
Leaves are the first warning signs of grape health.
- when affected by white rot, the leaves above the ring-shaped brown spots on the shoots also turn red;
- premature leaf erythema (with the exclusion of the main veins) is observed when the leaf curl virus and leaf reddening virus are infected.
- point lesions of the leaf plate - black spot;
- large rusty-brown spots between veins are a manifestation of fungal esca.
- dark spots indicate septoria;
- the browning of leaves also occurs with cercospora, verticillosis and ... with sunburn.
- brown spot of the leaf plate - the likelihood of spotted necrosis.
- easily erasable gray plaque above and below - oidium;
- velvety olive bloom on the back of the leaf - cercosporia.
- oily-like transparent spots are a sign of downy mildew;
- if such spots form a pattern, we are talking about a short knot;
- ruby-colored spots - a symptom of rubella;
- small brown or black necrotic spots - pronounced black spot;
- necrotic spots with a black border occur with anthracosis;
- light dotted spots are the first manifestation of septoria.
- leaves become smaller with eutipiosis;
- the fan arrangement of the veins of the modified leaves is observed in chronic infectious degeneration - short nodes.
Symptoms and signs
Usually, one symptom, manifested only in a particular leaf, is not enough for an accurate diagnosis.
Therefore, it is customary to compare 2-3 symptoms of the disease for the effectiveness of the selection of the measures used.
At the initial stage of the vegetative cycle, you can already see the first signs of infection on grapes:
- intensive shedding of flowers and ovaries may be the result of insufficient pollination with a unisex type of flower, or unfavorable weather conditions at the time of pollination, but Pierce's disease is accompanied by the same symptoms;
- inflorescences dry up under a white bloom - the first manifestations of downy mildew;
- gray fluffy bloom covering the top of the inflorescence indicates the appearance of gray rot;
After waiting for the period of ovary formation and fruit ripening, you can get several more indicators that clarify the diagnosis:
General bush change
A general change in the state of the bush, its morphology, growth rates and development phases is especially convincing for the assumption of a vine disease.
Main feature noncommunicable diseases grapes is their locality: the symptoms are not transmitted to nearby plants.
And, although in external manifestations there is a frightening similarity with various kinds of infections, they are not difficult to eliminate:
- lightening the structure of the soil;
- introducing missing minerals into its composition;
- helping the plant in difficult periods of weather anomalies (drought, prolonged rains);
- hiding the plant from low temperatures (at night, in winter);
- feeding the weakened plant with organic matter;
- changing the entire agricultural background for the better.
A strong, well-groomed plant is better able to resist any infection. And, if preventive measures of biological, mechanical and chemical processing are also carried out in the garden, then the chances of pathogenic organisms are even less.
But only recently bred hybrids, in the genetic structure of which resistance to fungal and some bacterial and viral pathogens was incorporated in the process of selection, have a full guarantee. Varietal selection is the most reliable protection from infectious diseases.
Watch a video on protecting grapes from disease in spring.
»Grapes
Although grapes are an unpretentious crop, they still require some maintenance. One of these activities is the prevention and treatment of diseases. While developing new grape varieties, breeders are working on this problem, but large-fruited varieties with a high sugar content are still susceptible to various kinds of diseases. In order to receive annually high yield the winegrower 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 culture are:
- mildew;
- alternaria;
- cercosporosis;
- armillariasis;
- oidium;
- chlorosis;
- rubella leaves;
- septoria;
- escoriasis.
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 the entire grape plantation in a short time. At the initial stage, it manifests itself in the form of light spots of yellow-oil color, the size of a penny coin on young foliage. On older leaves, the spots are angular and parallel to the veins.
When further development mycelium appears on the back of the leaf in the form of a white fluffy bloom. If the weather is warm with high humidity air, the fungal infection rapidly spreads to the tops of young shoots, whiskers, affects inflorescences and recently set fruits.
Formed given view fungal disease in summer period in leaf plates, where it survives the winter well.
Fungus spores are activated at a temperature of +10 degrees. The most favorable conditions for instant spread is 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 spores do not germinate.
Grape leaf infected with 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 a site for growing grapes;
- autumn mulching of row spacings;
- 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;
- fertilizing with mineral fertilizers;
- starting from the spring period, preventive treatment with Bordeaux liquid every 10 days.
Alternaria disease
Alternaria, or olive spot, affects grape leaves as a result of increased moisture. It appears as spots on the back and olive-gray bloom. With the active development of the fungus, the leaves dry out and curl.
This type of fungal disease also affects the fruit. During storage, the fungal infection spreads to healthy hands, affecting them. On fruits, the fungus manifests itself in the form of cracking and changes in the taste of the berries. The shoots affected by the fungal infection do not mature and do not tolerate wintering. Spores of the fungus overwinter on infected shoots, fruits and upper layers soil.
Alternaria on grape leaves The necessary preventive measures are:
- timely pruning of infected shoots;
- removal and burning of weeds and dry leaves;
- top dressing;
- treatment copper sulfate and Bordeaux liquid.
The beginning of the defeat of Alternaria grape berries Terms of preventive measures:
- During the period from March 21 to April 12 after tying the vine, spray it with copper-containing preparations.
- April 24 to May 9 to perform treatment with biofungicide. You can use the drug "Trichophyte" for these purposes.
- From May 16 to June 1 treat with the drug "Quadris". Continue processing every 14 days until the initial stage of berry ripening.
- From August 15th to September, after harvesting, prune the vine and burn it.
- October 20 to November 10 it is necessary to scoop out fallen leaves and treat the soil and vine with copper-containing preparations.
Treat with sprayers from the bottom. There will be no results when processing the top surface of the sheet.
Cercosporosis and how to deal with it
This fungal disease affects leaves, shoots, stalks and fruits. First of all, foliage close to the ground is affected, since the sun's rays poorly penetrate this part of the bush, and high 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. In direct sunlight, the fungus dies.
With a strong fungal infection, the grape bushes bear fruit poorly, the taste of the fruit deteriorates, the vine does not reach maturity.
It appears as an olive bloom 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.
The affected berries are covered with an easily erased olive bloom, hardened and fall off when touched.
Preventive measuresnecessary to prevent the disease:
- obligatory pruning of grapes twice a season;
- deep digging of the aisle in the spring and autumn;
- watering 4 times per season;
- weed removal;
- spraying bushes in autumn and spring with 1% solution of Bordeaux liquid;
- obligatory feeding.
- spray infected bushes with fungicides every two weeks;
- burn infected foliage.
Armillariasis affecting 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 secreting toxic substances, kills living tissue, after which it develops on infected cells. It is spread by fungal spores. Spores are extremely toxic and can kill the infected plant. Typically, infection occurs in spring, and in the fall, yellow mushrooms grow on the bush.
For the development of this disease, there must be high humidity and an 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 during the 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. Distinctive feature this disease is its rapid development at a high air temperature - above +31 degrees.
The first symptoms of the appearance of Aspergillus rot on grapes. It is necessary to remove diseased berries At the initial stage, a berry affected by another fungal disease becomes a beneficial breeding ground for the Drosophila fly.
At first, a little noticeable appears on the berries white bloom, then dark depressed spots. The skin in these places shrinks and cracks. The flesh 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 fungal spores;
- 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, inflorescence shoots. Inflorescences do not develop or ripen when damaged. This disease lives and progresses only on living cells. Hibernates in cracks in the bark and on buds.
Spores, falling on leaves, multiply rapidly, carried by the wind. Exceptional conditions are high air humidity (over 80%). Depending on the temperature regime incubation period lasts from a week to two weeks. Favorable temperature for rapid development 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 bloom that appears on the bunches and flowers resembles flour;
- shoots are covered with dark spots;
- dead areas appear on the processes.
Prevention measures are as follows:
- digging up soil, cleaning foliage and weeds;
- feeding with phosphorus-potassium fertilizers;
- treatment 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 with 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 appears as spots on bright lemon-colored sheets. The shoots stop developing, and the leaves dry out and fall off. The fruits become small and do not reach maturity. A weakened bush may not survive wintering.
Prevention of this disease is the treatment of bushes with the drug "Chelate".
Chlorosis-affected grape leaves acquire a rich lemon shade Rubella leaf
In late spring or early summer, grape bushes can become infected with this fungal disease. It affects grape leaves damaged by insects.
You can determine the infection of the bush with rubella by the following signs:
- sheets in the affected area have spots like maple leafcovered with a rusty bloom;
- 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 with a yellow border;
- in dark varieties, the spots are bright red.
To avoid infection you need:
- process leaves with Bordeaux mixture;
- carry out regular pruning of bushes;
- rake and burn fallen leaves;
- apply top dressing to the soil;
- dig up the aisles.
Septoriasis
Typical for Muscat grape varieties. It appears as small brown spots on sheets. If the humidity is high, then mold forms on the underside of the leaves. When dry, it falls off and spreads the 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 mold and dry out. Escorosis disease
Escoriosis is a dangerous fungal disease that affects all parts of the plant. It represents black spots on the leaves and shoots of the bush. Fastest spread 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, you can apply the treatment with Bordeaux liquid.
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:
- obligatory application of fertilizers containing zinc and boron;
- timely formation of the bush;
- removal and incineration of affected parts;
- using healthy seedlings for planting.
To protect the vineyard from disease, it is necessary to comply with the conditions for growing grapes and timely carry out preventive measures to prevent the spread of infections. It is recommended to plant those varieties that are most suitable for growing in the region.
Grapes are one of the oldest and most popular crops. Thousands of years ago, the fruits of grapes could be found on the tables of queens, and wine was served at all receptions for noble persons. Little has changed today. However, getting a generous harvest is becoming more difficult every year. The reason is that the plant is often affected by bacterial, viral and fungal diseases. You will learn all about grape lesions, leaf diseases and plant treatment from the article.
We invite you to learn about common diseases of grapes and methods of control
Grapes: diseases and the fight against them, photo
Fungal diseases are among the most dangerous for grapes. Every year, common diseases lead to the death of more than 50% of the total crop. Given these trends, it is important to pay due attention to the prevention of fungal diseases and, if necessary, take decisive action to treat the plant.
In the photo mildew
Mildew - pseudo powdery mildew or peronosporosis. This fungal disease very often affects plantings and is well known to the winegrowers of the world. With insufficient prevention, it leads to severe damage to the bushes and the loss of the entire crop.
It is not difficult to determine the defeat of the leaves by spores of the fungus and it is worth paying attention to the following symptoms:
- lightening a limited area of \u200b\u200bthe sheet;
- whitening of young shoots and whiskers;
- drying out of inflorescences;
- wrinkling of fruits;
- premature fall of foliage.
In the photo, grape berries affected by powdery mildew
According to the observations of experts, it became obvious that mildew spreads especially actively if the weather is warm and humid for a long time. This creates ideal conditions for the reproduction and spread of the spores of peronospora. If you do not take timely measures to protect the grapes, all the bunches may disappear.
Dense plantations of grapes, overgrowing of rows with tall weeds, improper or insufficient pruning of grapes in the spring contribute to the defeat. Unfortunately, when the first signs of the disease appear, the bushes can only be saved with copper-containing preparations or potent fungicides, for example, copper sulfate, dichlofluanide, cinos. With these means, it is necessary to spray not only the affected area, but also those shoots that still look healthy outwardly.
Oidium - true powdery mildew, or ashtray, is caused by a fungus that loves warm and humid weather. Within a short period, all grapes affected by powdery mildew are covered with a white, velvety bloom. The mycelium affects the entire leaf, shoots, and throughout the entire time produces spores, which are carried around the area with drops of rainwater or wind.
In the photo oidium grapes
With the arrival of autumn, oidium grows and the plaque turns gray. When the berries are damaged, the latter crack, and their contents flow out of the fruit along with the seeds. With significant lesions from grapes begins to emanate bad smell rotten fish.
Winegrowers use sulfur or preparations based on it to treat infected plants. Leads to good results with Topaz, Bayleton.
Diseases of grapes and their treatment with photo, video
Anthracnose or grape pox is another fungal disease that is widespread in the Black Sea regions, Moldova and the Caucasus. The fungus-causative agent of anthracnose is able to persist on the branches for several years, it tolerates any unfavorable climatic conditions well. Having overwintered on grapes, the fungus begins to multiply intensively with the arrival of the first spring heat and rains.
In the photo, grape anthracnose
It is possible to suspect infection of grapes with anthracnose when the following signs of the disease appear:
- the appearance on fruits and leaves of brown spots surrounded by a white corolla;
- cracking of tissues and the formation of deep lesions;
- drying out of inflorescences.
In areas where anthracnose is common, it is better to plant disease-resistant grape varieties. For prevention, you need to treat shoots with fungicides. For this purpose, use Kuproksat, Horus, Acrobat.
In the photo, black spot or escoriasis
Black spot or escoriasis is the death of grape shoots due to the defeat of their dangerous fungus... Woody branches are predominantly affected, as a result of which they become discolored, covered with black spots. After a long development, the affected areas rot, crack, and the grape sleeve dies off completely. The affected leaves dry out and fall off, and the berries acquire a rich purple hue.
Infection is facilitated by the formation of infection on the branches of the entrance gate - wounds, cracks, breaks. Spores of the fungus fall on these areas and after a while the infection spreads to the entire plant.
Unfortunately for winegrowers, treatment of black spot with drugs is ineffective. Annual prophylaxis is the only protection. To do this, the plant must be sprayed with copper preparations, and pruning must be carried out regularly.
Grapes: leaf diseases and treatment, photo
Cercosporosis - fungal disease of the plant. Green mold appears on the leaves, which is easy to remove. The affected area may be surrounded by a dark border. Leaves infected with cercosporosis dry up and fall off. Plaque can also grow on berries, which become hard and crumble spontaneously.
In the photo, cercospora is a fungal disease of grapes
According to the observations of biologists, the growth and development of fungal spores depends on the level of illumination. In the shaded areas of the vine, the fungus grows faster. The target of cercosporosis is lower leaves and shoots located close to moist and hot ground.
When starting the treatment of cercosporosis, the first thing to do is to form the vine correctly when pruning, not to overuse watering and not to thicken the planting culture. In the fall, it is recommended to dig up the soil, and tie the overgrown branches to the trellis. Fallen leaves must be collected and burned, and when the first signs of damage appear, spray the branches with fungicides.
In the photo, bacterial cancer of grapes
Bacterial cancer - one of the incurable and fairly common diseases. As you can see in the photo, bacterial cancer disfigures bushes. Having found sleeves with growths characteristic of cancer, you need to cut them out and burn them. The resulting stump must be treated with a potent pesticide such as DNOC or copper sulfate. The tool that was used to remove the sleeve must be disinfected. The soil under the vine with bacterial cancer should also be treated with copper sulfate.
The favorite culture of many is grapes, leaf disease and its treatment at home is a particularly relevant topic. In some regions, it also suffers from pests. However, it is possible to save the harvest and prevent the appearance of diseases if important recommendations, the advice of owners who have already mastered them.
Most winegrowers are faced with various diseases of their favorite culture. Diseases of the leaves of grapes not only spoil its appearance, but also destroy the foliage in the vineyard, ruin the precious harvest and greatly weaken the bushes.
Healthy grape foliage has a uniform green color. If uncharacteristic spots, bloom, defects suddenly appear on the leaves, then the grapes are not in order. What to do if grape leaves are sick? It is necessary to determine the disease, than to treat it, and as soon as possible to begin the fight against the disease.
- Infectious lesions:
- fungal
- bacterial
- viral
- Diseases caused by pests
- Non-communicable diseases:
- caused by improper care
- caused by a lack of trace elements
Infectious diseases of grapes
Leaf infections are caused by fungal, bacterial or viral infections. Most often, gardeners are faced with fungal diseases. The most dangerous and common diseases are mildew, oidium, anthracnose.
Mildew (downy mildew of grapes)
The most formidable attack on vineyards is mildew, or downy mildew of grapes. This disease affects all vegetative organs of the plant - leaves, shoots, bunches.
The source of infection is the spores of the fungus, preserved in the soil, on fallen leaves and berries, are carried by the wind over long distances. Plant infection usually occurs in the spring when the weather is warm and humid. Spores actively germinate; during the season, the disease can re-produce several generations.
What does it look like
Yellow oily spots appear on the leaves of grapes, which increase, often covering the entire surface. A mealy bloom of sporulation appears on the underside of the spots in wet weather. Severely affected leaves turn yellow, dry out and fall off. The berries turn brown and rot. Brown spots appear on the shoots, the vines become unsuitable for reproduction and often die in winter. The disease is most dangerous for young growing leaves and bunches, old leaves are less affected.
How to warn
Measures for the prevention of mildew, like all fungal diseases, are aimed at improving the ventilation of the bush and eliminating sources of infection.
- tying up shoots to raise them above soil level;
- pinching, thinning, breaking shoots;
- destruction of fallen leaves and berries by burning;
- preventive spraying with fungicides.
How to treat:
The fight against mildew consists of spraying the grapes with fungicides. These are copper preparations (means of contact action) - one percent Bordeaux liquid, HOM, Oxyhom, Polychom, Kuprozan and systemic fungicides: Ridomil, Strobi, Thanos.
During the season, the grapes are sprayed several times. The first treatment is carried out when the shoots reach a length of 20-30 cm. The second time the grapes are sprayed before flowering. The third treatment is carried out after the flowering of the grapes.
Oidium (powdery mildew)
The disease affects all vegetative parts of the shoot. Diseased sprouts are covered with an ash-gray bloom, because of which the disease was called powdery mildew. The infection hibernates as a mycelium in infected shoots and buds. Shoots growing from such buds are distinguished by a gray color.
What does it look like
Spots appear on the upper side, which then merge. Grape shoots are covered with a gray mold. Infected tissues turn brown, leaves dry and fall off. The bunches dry up, the berries turn brown and crack.
How to warn:
- Thinning bushes, garter and pinching
- Destruction of plant residues
- Weed weeding, soil loosening
- Pruning infected shoots.
How to treat:
The use of sulfur preparations is effective against oidium.
The first treatment with a solution of colloidal sulfur at the rate of 90 g per bucket of water is carried out before flowering. Of systemic drugs applied: Fundazol, Tiovit-jet, Strobi, Skor, Horus, Topaz.
Anthracnose
Anthracnose is another fungal disease that affects all green plant organs. The development of anthracnose is provoked by heavy rainfall. The causative agent of the disease hibernates in plant residues... In case of severe damage, the grapes lose their leaves and shoots, the berries become smaller, the quality of the crop deteriorates.
What does it look like
Brown or reddish depressed spots, have a dark purple border. The same spots are formed on infected berries. The areas affected by the disease die off, often fall out. The leaves turn black and dry, the shoots crack.
How to treat
Prevention and treatment measures for anthracnose are the same as for mildew control. Chemicals: HOM, Polykhom, Arcerid. Shoots affected by anthracnose are cut off and burned.
Black spot
Small black dots that form along the veins of the surface subsequently increase in size. The spots merge, curl appears, cracks in the leaf blade. The foliage turns yellow, the shoots crack, the berries rot.
How to treat
Autumn processing with Bordeaux mixture before grape shelter. Spring processing drugs Ridomil, Horus, Tiovit.
Viral diseases of grapes
They are caused by microscopic pathogens that are transmitted through infected planting material, and are also carried by various pests: nematodes, ticks, and other gnawing and sucking insects.
Among viral diseases, the greatest damage to vineyards is caused by viruses of the short-knot of grapes, a virus of leaf rolling, infectious chlorosis (variegation).
How to warn:
- Acquisition of healthy planting material;
- Pest control of vectors of viruses;
- Destruction of diseased plants.
Leaf diseases caused by pests
Spider mite
The spider mite is an almost omnivorous pest that lives on weeds. The mite reproduces in large numbers by sucking the juice. Grape leaves wither, turn yellow, photosynthesis is disturbed in them. Severely affected dried up - fall off.
What does it look like
The grape leaves are covered with thin cobwebs. The smallest pests can be seen on the underside. The foliage of the grapes turns pale and dries up.
How to treat:
Preparations Nitrafen (3%), Phosphamide, Rogor, Talstar, Kinmiks, Neoron, Aktellik. Insecticides are applied so that not only the upper, but also the lower side is wetted. Processing is carried out in the spring after bud break, if necessary, repeat in June.
For prevention, it is necessary to carefully weed the plantations of grapes, removing weeds.
Grape mite - itch
The pest hibernates in bark cracks, bud scales and fallen leaves. With the onset of heat, the mite begins to feed on the plant cell sap, causing leaf deformation and disrupting photosynthesis. The tick affects not only them, but also shoots, young ovary. In addition, the pest carries fungi and viruses that are dangerous for grapes.
What does it look like
Grape itch is the smallest pest, it is difficult to see it with the naked eye. The presence of itching can be determined by the appearance of the grapes - the characteristic blistering swellings. Leaves wrinkle, acquire curliness, reddening tubercles. Inside the tubercles, a light felt coating is noticeable, which subsequently turns red or turns brown.
How to treat:
During the budding period, the grapes are sprayed with Phosphamide at a concentration of 0.2%. The treatment is repeated after two weeks, if necessary, repeat in the summer. You can use anti-mite drugs - Neoron, Fufanon, Kinmiks, Actellik and others.
Phylloxera
How to treat:
Phyloxera does not like sandy soils, so sand is introduced under the roots of the grapes. They also use the method of partial flooding of the roots of grapes, spraying with Hexachlorin.
Leaf roll
A leafworm is a butterfly whose caterpillars do harm grape leaves... The caterpillars wrap the leaves in a tube, gluing them together with cobwebs, which subsequently dries up and turns brown.
How to treat:
Spraying the bush with insecticides. Removal and burning of dead bark, under which the pupae of the pest hide.
Non-communicable diseases
Changes appearance grape leaves can be caused by improper care or deficiency nutrients.
Chlorosis
TO non-communicable diseases grapes include chlorosis - loss of green color. Chlorosis can be caused by various reasons: acidification or alkalization of the soil, lack of iron and other elements, cold weather, excess nitrogenous fertilizers. Chlorosis of a viral nature occurs.
What does it look like
Young leaves grow pale with yellow tint, underdeveloped, the shoots become smaller. The shoots become brittle, the grapes do not bloom.
With a lack of nitrogen, on the contrary, old leaves turn yellow, young ones grow green.
How to treat:
Non-infectious chlorosis is fought with the introduction of iron preparations. In the spring, spray with a solution of ferrous sulfate 1% (100 g per bucket of water). Spraying is carried out in the morning or evening, but not in direct sunlight. Ferrous sulfate is also used to fertilize the soil.
An atypical color can be caused by a lack of manganese, boron, zinc. The lack of trace elements is compensated by the introduction of complex fertilizers and foliar dressing.
Lack of nutrients and trace elements
An atypical color can be caused by a lack of essential substances in the soil.
What does it look like
Lack of nitrogen - small light green leaves and shoots.
Lack of phosphorus - the formation of small dark green leaves, dotted browning at the edges. Veins and petioles turn red.
Lack of potassium - the lower leaves acquire a blue-violet color, sunburn appears.
Lack of magnesium - discoloration of the edges, between the veins. In red grape varieties, the leaves turn red.
The disadvantage of boron is the appearance of a mosaic color, shredding of shoots, the edges are bent down.
Lack of zinc - sharp-toothed shape, brittle surfaces, asymmetrical.
How to treat
- Liming acidic soils
- Application of complex fertilizers
- Foliar dressing with microelements.
Chemical analysis of the composition of the soil and determination of the lack of substances are within the power of only specialists. The gardener's job is to improve physical properties soil, apply top dressing and fertilizers correctly.
