How to treat fungi on grapes

With what and how to treat diseases of grapes?

Like any other crop, grapes are prone to many diseases. Sometimes it is due to improper care, and sometimes bad weather makes its own adjustments. In any case, you need to know the enemy in the face and know how to fight it.

Diseases of grapes: description, signs

Grape diseases are commonly divided into several categories: fungal and viral. The first is the most well-known and widespread. To cure infected bushes, it is necessary to use fungicides. The second category is the most serious. In most cases, treatment does not help, you have to completely remove the bushes and observe quarantine measures.

Fungal diseases of grapes

• Mildew (false mildew). The most common fungal disease of grapes. Appears as yellow spots and gray (moldy) surface. Affected areas dry out quickly without treatment. In wet weather, the disease develops lightning fast. It is impossible to cure such a plant completely – the fungus is inside. It is possible to prevent the course of the disease only with the help of special preparations.
• Oidium (true mold) is the second most common fungal disease. Affected leaves are covered with a gray plaque. The disease can occur at any time of summer. Favorable environment for the development of pathogenic bacteria is air temperature within +25 degrees. Ironically, heavy rains can stop the spread of the disease. If the plant is heavily infested, the skin of berries begins to tear, and the fruits become unfit for consumption. If something is not done in time, you will be left with no harvest, and in 2-3 years you will forget about the existence of the vineyard.
• Alternaria is a fungal disease. The main symptom is the presence of brown or silvery spots on the plant. Leaves, fruits, leaf stems and shoots are susceptible to the disease. If berries are struck, they become covered with a white film, shrivel up, and spoil quickly. A prolonged spring is a favorable prerequisite for the rapid development of Alternaria.
• Bacterial cancer is a fungal disease that mainly affects vineyards. A clear sign is the growths that appear on the shoots. There are no remedies to help cure the plant. Therefore, it is better to immediately pull and burn the affected bush. It is noteworthy that no grapes can be planted in its place for three years.
• Apoplexy is a disease that leads to the sudden death of the plant. Experts explain this phenomenon by the fact that pathogens produce toxins in the plant. They destroy the plant. Weakened bushes are most susceptible to this disease.
• Gray columnaris is a fungal disease. Appears in the form of gray spots. Can form everything: discs, tendrils, inflorescences, fruits, etc. The crop is unfit for food. It is especially dangerous when the fungus forms on grapes. All fruit can be affected by the infected berry. – A clear sign of the disease is a white coating on the stalk and berries of the plant. The fungus appears most often after a hailstorm – when the plant is damaged. Infected berries turn and then fall off.
• Black rot is a disease in which purple spots form on the leaves, berries. Over time, the affected areas overgrow with banishment and fall off.
• Verticillosis – characterized by rapid shoots. In the acute form, leaves turn yellow and fall off. Infection can occur through damaged branches or through the soil. The fungus persists in the ground for about 4-5 years, so during this time it is not recommended to plant grapes in an infected place.
• Clear signs of the disease are lesions on the leaves and damage to the roots (they become sluggish and turn brown). Usually these signs appear in the spring, and in the fall, yellow fungi grow on the dead bushes.

Viral diseases of grapes

Viral diseases are not currently studied. A certain group of viruses can cause diseases. In particular, we are talking about infectious chlorosis, yellow mosaic, result mosaic, etc. The main signs that may indicate that the plant is infected with a virus include:

• Slow development of the bush;
• Weariness of the inflorescences;
• Curling or deformation of the leaves;
• Exceptional coloration of leaves, such as multi-colored leaves;
• Cracking of the wood.

Unfortunately, in this case, no measures help. The affected bush is simply uprooted and burned. The infected place is not used for new plantings for at least 5 years.

Getting rid of diseases: a list of the most effective medicines

The list of drugs that help to fight grape diseases is great. Now we will tell you about the most famous and effective of them.

Strobi – fungicide: Instructions for use for grapes

Strobi – fungicide is a drug designed to combat fungal diseases. These include:

• Phytophthorosis;
• Peronosporosis;
• Rust;
• Powder.

It is worth noting that this product has many advantages. In particular, the drug is safe for insects (this is important for beekeepers), and can also be used during flowering.

The principle of action: the active ingredient is cresoxime-methyl. It spreads evenly on the surface of the leaf and creates a gas-like coating which protects the surface of the plant.

Application: 5 g of strobi is required per 10 liter bucket. The prepared working solution should be applied evenly to the system. This should be done early in the morning in sunny weather.

It is recommended to use the prepared product at least 2 hours after its preparation. Otherwise, the long-awaited effect will not be achieved.

Treatment is carried out 2 times per season (this is enough). The interval between them should be 10 to 14 days. The last treatment should be carried out at least one month before harvesting.

Ridomil Gold: instructions for use for grapes

This drug is also widely used. It is effective in the fight against mildew.

The principle of action: in the composition of Ridomil Gold there are such components as Mancotke, Mephaanken. The first protects the surface of the leaves, and the second penetrates into the grape bush and thus provides internal protection. After treatment, the system is fully protected for 2 weeks.

Application: To prepare the active solution you need 10 g per 4 L. Water. The treatment is carried out by spraying the working solution on the system. It is desirable to carry out this action during vegetation period. Interval between sprays is 10 to 14 days. The last treatment should be carried out not less than 2 weeks before harvesting.

Ridomil Gold is a preventive agent. It helps prevent disease. If the plant is already infected, you should first apply a medicinal fungicide, and then use Ridomil (after about 7-10 days).

Topaz: instructions for grapes

This drug is effective against mildew and oidium. It is available in the form of emulsion in ampoules.

Principle of action: After treatment, the active ingredient penconazole is quickly absorbed by the plant. It penetrates the product and prevents the formation of new fungi. If the application of “Topaz” was carried out at an early stage of the disease, the effect is most pronounced.

Application: One ampoule is enough for a 10-liter bucket. The prepared solution should be sprayed on the plants affected by the fungus. It is best done early in the morning or in the evening in dry and windless weather. Repeated treatment of grape bushes can be carried out after 10-14 days.

When preparing a useful solution, it is necessary to observe some safety measures. In particular, it is recommended to use special protective goggles and gloves.

Tiovit Jet: instructions for use for grapes

“Tiovit Jet” for grapes is in no way inferior in effectiveness to the above preparations. It copes well with oidium.

The active ingredient of the drug is sulfur. It is sold in the form of pellets. The weight of a packet is usually about 800 g.

The principle of action: Upon contact with the plant, sulfur is released, which then reaches the pathogenic cells and completely destroys them in a few hours.

Treatment with the drug should be carried out in warm weather. At low temperatures sulfur does not evaporate, so the desired effect does not occur.

Application: “Jet” is very economical to use: 30-80 grams are enough per 10-liter bucket of water. Substances. Treatment is done by spraying, mostly in the morning. The product can be used up to 5 times in a season. When using the drug, don’t forget to make sure that the working solution is evenly distributed on the leaf surface. Jet starts working about 2 hours after spraying.

Quadris: instructions for vine application

Quadris – the use of this drug for grapes is very common. This is due to the fact that with its help you can get rid of many diseases. Among them:

• True mildew;
• Mildew, Oidium;
• Alternaria;
• Late blight;
• Peronosporosis.

Application: The drug can be used for prophylaxis and directly to control the disease. Treatment (spraying) of plants is best done in the morning, when the sun’s rays are not yet so merciless. The main feature of this remedy is that it must be interchanged with other preparations. For example, you can first treat plants with Quadris, then Horus, and then Quadris again.

How it works: Quadris has a unique effect on the treated plant. If it hits the affected areas, the disease can recede within 3 days.

The advantage of “Quadris” is that it can be combined with many preparations. To get a 100% result, the drug can be mixed with Ridomil, Topaz or Revus. The second undeniable advantage is that this preparation shows good results in wet weather and therefore copes well with fungal diseases.

You should not treat when the leaf surface is wet or when precipitation is expected in the near future.

And one more important point – repeated application of the preparation is allowed not earlier than after 2-3 weeks.

To summarize, it is important to note that disease is easier to prevent. At the moment when the plant is already infected and there are obvious signs of the disease, there is less hope for a good outcome. Of course, you should be prepared for the fact that even if the grape bush is lucky enough to recover, the yield will still decrease. In any case, the use of fungicides is justified, and sometimes the only way out of the situation.

Diseases of grapes: characteristic symptoms and treatment methods

Even in ideal conditions, grapes are not immune to infection by fungi, viruses and bacteria. To defeat the enemy, it is important to know the main symptoms of its appearance at the time of planting and take preventive measures in time.

Introduction

Grapes are a difficult garden crop to grow. This southern, heat-loving plant is extremely demanding to the conditions of maintenance, so even with the observance of the norms of agrotechnics, it is prone to various infections.

Timely detection and identification of the signs of infection and the application of appropriate treatments will help to overcome them and save the harvest.

Fungal diseases and their symptoms

Grape diseases caused by different types of fungi are the largest and most common group. Getting into the root system or on the aerial part of the plant, phytopathogens begin to multiply actively and disrupt physiological processes in tissues.

Spores and mycelium remain in the soil and plant debris, are carried by pest insects’ paws, get on the vine from clothes, hands of the gardener, and dirty tools. Under favorable conditions, pathogens become active and infect the bush.

Mildew

A disease that affects only grapes. Its causative agent is a fungal microorganism Plasmopara viticola – a fungus-like organism, a relative of blue mold, a member of the family Peronosporaceae. It infects the vine at high humidity at temperatures from +10 to +30 degrees.

Characteristic signs of the disease:

Oily spots with yellow or reddish tinge on the upper surface of leaves at the early stage of infection.

To prevent powdery mildew before flowering and after harvest, use spraying with folk remedies and preparations: Hom, Oksihom, Kuproksat, Bordeaux mixture, Ridomil Gold.

The ground and aerial part of the bush is treated. The use of biofungicides gives good results: Alirin B, Trichophyte, Gaupsin, Phytosporin.

To treat heavily infected bushes, systemic fungicides that penetrate the plant tissues and act from within are used: Horus, Quadris, Skor.

They can be used until the size of berries reaches the size of a pea. While watering the fruits, the bushes can only be sprayed with folk remedies or biofungicides.

The following grape varieties have high and medium resistance to powdery mildew: Moldova, Codreanca, Arcadia, Victoria, Gold-resistant, Buffalo, Nistra, Vostorg red, Alpha, and Lily.

In regions with humid climates, it is not recommended to plant European varieties most susceptible to the fungus: Pinot, Cardinal, Chaush, Rizamata, Muscat, Hamburgsky.

Oidium (ash skin or powdery mildew).

The causative agent of the disease is the related fungus Oidium Tuckeri, which becomes active in moderately warm and humid weather. The sign of infection is a white, flour-like plaque on the upper part of the leaves.

Due to lack of nutrition, leaf plates and young shoots gradually become deformed, dry out and fall off. The spores then penetrate the fruits, which burst and then rot.

To prevent mildew in early spring, bushes are sprayed with Bordeaux liquid or copper sulfate after the first leaves open. Treated with Topaz, Prognoz.

Alternaria (olive blotch).

The causative agent of the disease is a fungus of the genus Alternaria, which activates at high temperature and humidity. Most often the first signs appear in May.

Leaves are covered with silvery or yellowish spots, which darken over time. In the later stage of the disease, the spots turn black.

If the disease is left untreated, the spores spread to the fruits. They shrivel up and become tasteless. The fungus can survive even on harvested grapes, so the disease often occurs during storage of the crop.

To treat alternariosis, the drugs quadris, scor, cabriole top are used. For prevention in early spring, bushes are treated twice at 2 week intervals with a Bordeaux mixture or copper sulfate.

At all stages of disease development can be sprayed with trichodermin with biofungicide phytosporin.

Anthracnose (spotted, “bird’s eye”)

The disease is characteristic of regions with warm and humid climates. Symptoms of infection:

• Dark dots on young leaves in the early stages of infection;
• Gradual transformation of the dots into brown, purple or violet-brown depressions with a dark border;

• Oval indentations on the discs in severe lesions;
• Cracks in the bark at spots of darkening.

If the last sign is observed, it is pointless to fight the fungus, because the spores have settled in all plant tissues.

The only way out in this situation is to uproot the infected vine and carefully treat the healthy plant and the soil in the place where it is located.

The method of treatment depends on the stage of the disease:

1. When the first signs appear, spraying with a 3% solution of Bordeaux liquid is carried out. After 7 days, the process is repeated, but already with 1% composition.
2. As the disease progresses, the plant is sprayed with a solution of copper sulfate (100 g / 5 L) or biofungicide.
3. If the bush is heavily infected, chemical fungicides are used: Ordan, Kuproksat, Acrobat MC, Fundazol, DNOC and Previkur. After the first treatment, the next one is carried out after 14 days. It is recommended to spray plantings with these strong compounds in late fall (after cutting) and early spring.

Gray columnwort (Botrynose).

A dangerous disease that is difficult to treat. The fungus first affects the lower parts of grapes. They are covered with a fibrous gray plaque.

Thick plantings, contact of branches with the floor during premature gartering, and overfeeding with nitrogen fertilizers contribute to the infection.

Treatment of bushes to kill the fungus should be carried out at the first development of the disease, since the spores later germinate inside the vine and they can no longer be fought.

Preparation for gray column treatment: Medea Ya, Titul 390, Switch, Horus, Antracnol.

Aspergillus rot.

The disease affects fruits on bushes in dry, hot weather and during storage. At first, light spots appear on the berries, which then darken, the flesh begins to crumble and burst. Cracks form a white, then black-brown soft surface. Clusters completely covered with spores look black.

If symptoms are detected, immediately remove all damaged brushwood. Treat the bush with a mixture of copper vitriol (5 g) and potassium iodide (2 g) per 10 liters of water.

In case of strong infection, you will have to sacrifice the harvest and treat the vine with Fundazol or Ridomil Gold to save the vine.

White rot (white mouth, “hail disease”)

White rot is a fungus that affects damaged fruits when heat hits them. At first, small yellowish spots appear on them, then they turn creamy. Then the berries wither away.

The shoots become covered with light spots, and the leaves darken. In the zone of risk overgrown, prematurely pruned bushes.

Preparation for white rot treatment:

In spring, bushes are sprayed with topaz for prevention. In warm, rainy weather, treatment is carried out 4 times with an interval of 10-14 days.

Black rot (black mouth).

When infected with this fungus, the fruits and leaves turn dark purple or black. The disease progresses quickly, especially in conditions of high humidity.

For treatment, bushes are sprayed with topaz, anthracnol or copper preparations.

Verticillosis (wilt)

Verticillosis (wilt) is a disease caused by the fungus Verticillium. The pathogen settles in the root system, penetrates from the ground or requires no water when watering.

The spores of the fungus have an increased ability to survive. They can live in the ground for up to 10 years and do not die even in severe frosts.

The development of the disease begins with the introduction of warming. The cold stops the growth of the spores, but the phytopathogen does not die, but hibernates. Wilkes disease symptoms:

• Discoloration of shoots;
• Appearance of burns along the edge of the platinum leaf;

• Withering and dieback of stems;
• Absence of ovaries and fall of flowers.

If such signs appear, the affected tissues, discs and roots of the bush should be sent for analysis. In a special chamber, the spores are germinated for 2 days and then examined under a microscope.

apoplexy

The fungus affects mostly old bushes. The lower leaves turn back between the veins and wither at the edges. The fruit shrivels and darkens, and the wood becomes lazy. Sometimes the plant dies quickly.

Armillariasis

A fungal disease that affects all parts of the vine: roots, branches, leaves, flowers and ovaries. At first they turn yellow, and closer to fall they turn brown or brown.

Copper-containing fungicides are used to treat Armillariasis: Hom, Oxyhom, Cuproxate, copper vitriol.

Diplodia .

The fungus affects fruits, rarely wood. The berries turn blue-black, the surface is covered with small tubers. The wood cracks. Heat combined with high humidity provokes the growth of spores.

The fungus is destroyed with Bordeaux liquid and copper-containing preparations. Before this, all infected parts must be removed from the vine.

Penicillosis

The disease is often found under the names “Graufäl”, Penicillary Schimmel, “Blaufäl”. Favorable conditions for the growth of spores are moisture combined with coolness.

For treatment, the shrubs are thinned and treated with Fundazole, Skorom, Benomyl.

Fusarium .

The causative agents of the disease are fungi of the genus Fusarium. The parasites can live in soil and plant debris for a long time and become active with the onset of a cold prolonged spring with frequent rains.

A sign of spore reproduction is a yellow discoloration of the leaf plate between the veins. This symptom is similar to chlorosis, so inexperienced growers choose the wrong treatment tactics. Treatment with Ridomyl Gold, Delan, and Kuproksat helps to defeat myssel.

Treatment is carried out for 2 months with a frequency of 1 time per week.

Moniliosis (moniliac blight).

The disease affects grapes during flowering. Buds turn brown and small white pustules with spores form on petioles.

The fungus is carried by wind and insects. Optimal conditions for its reproduction are air humidity of 90% and temperature of 15 – 20 degrees Celsius. Preparations: Abiga-Pik, Alirin-B, Kuproksat, Mycosan, Nitrofen.

Black spot disease (eskoriosis, fomopsis, dryness)

The disease got its name because of the appearance of black plaques on all parts of the plant during infection.

If all affected areas are not removed, the bush dies. Treatment with Medea-M for bleeding smear is carried out to reveal the buds.

Eutiposis (dry sleeves, sleeve dieback).

Caused by the fungus eutipus Armeniaceae Hansf. and a dense film. It affects the woody parts of wine bushes. Necrosis often occurs on older vines and is not usually visible under the bark of perennial rootstock. It tends to expand more rapidly in length than in width.

The sleeves (tree trunks) should be removed at the beginning of the growing season, when signs of the disease become discernible.

It is recommended that the tree be removed at this time because the wounds are least susceptible to infection and ascospores are less likely to become infected.

Bacterial diseases.

Grapes are affected by 3 types of bacteria: saprophytic, bacilliform and soil bacteria. Each of these groups includes about 100 species of bacteria. Almost all are carried by insects, birds and, less frequently, humans.

Diseases develop quickly and can completely deprive the gardener not only of the harvest, but also of all grape plantings.

Berry bacteriosis

The process begins during the formation of the ovary. The brush is partially infected. This is especially dangerous in hot weather, when the bunches are on the sunny side. The main signs:

If the pathology progresses, the berries wither within 7 days. It is important to prevent the development of bacteriosis:

• Protect the fruit from sunlight;
• Avoid mechanical damage.
• carry out phytocarantine when purchasing new seedlings;
• perform a number of measures to protect against pests that violate the integrity of the crop.

Bacterial necrosis (bacterial charmer, Oleiron’s disease)

A disease that affects the entire above-ground part of the plant. The symptoms are creeping?

To combat necrosis, a 5% solution of Bordeaux mixture is used. Equally effective are sulfur-based preparations in the early stages of infection and subsequent treatment with a 2% bordeaux mixture solution if the leaves are budding.

Pierce’s disease.

The causative agent of this disease is the Gram-negative rickettsia-like bacterium xylella fastidiosa of the gammapa class, and there is leaf desiccation that begins at the edges.

Drugs to treat this disease have not yet been developed. Experts advise growing varieties that are resistant to the bacteria.

bacterial cancer

The causative agent of the disease is the bacterium Agrobacterium vitis. It is activated when the immunity of the plant is reduced, especially when the shoots freeze in winter. Signs of the disease:

The most dangerous symptom is swollen branches. They disrupt the processes of photosynthesis, so the bush completely stops in development.

It is possible to cope with the disease only in its early stages. For treatment, the drugs Phytoplasmin, Phytoflavin are used.

viral diseases

The danger of viral wine diseases lies in their incurability.

Experienced gardeners know that the only proper solution in case of virus infection is to uproot the bush. If this is not done, in a short time the disease will destroy all vine plantings.

Infection with the virus occurs when planting young seedlings or during an attack by insect pests. Symptoms of the disease are much the same as fungal diseases, so growers often conduct fungicide treatments, allowing the virus to penetrate plants adjacent to the infected bush.

Short knot (infectious degeneration)

The first symptoms of this infection appear when it becomes chronic. When the infection is recent, heart-shaped or linear patterns appear on the leaves.