Treatment and effective methods of combating grape rubella

The causative agent of the disease

Ascomycetes - who is it? How dangerous are they for plants?

Translated from Greek - simply “bag”, “bag”. Marsupial mushroom. An imperfect organism (mycelium), which has a vegetative body in the form of thin threads (hyphae) and special organs for bearing spores (reproduction cells) - bags. The reproduction of ascomycetes itself is carried out asexually (without reproductive cells) and sexually (through the interaction of specialized cells).

80% of plant diseases are associated with spore organisms. The causes of fungal diseases are not always the same, and the fight against them is protracted.

The essence of a plant being damaged by a fungus is its penetration through the stomata of the leaf surface or damage left by pests, and intensive germination into the body of the plant.

Rapidly spreading, the mycelium creates at its ends - due to the fusion of male and female gametes - more than 100 bags (each with 8 reproductive spores). On the surface of the leaf, the bags, closing, form “saucers” with a diameter of up to 400 microns.

Thin threads (hyphae) of the fungus intertwine to form bundles and new fruiting organs. The main purpose of multi-meter threads is to absorb water and nutrients from the plant. The period of ripening of spores in bags at a temperature of 20 degrees Celsius is 2-3 weeks. They are transferred by streams of water or air to other plants, combining for a new act of fertilization.

Asexual (vegetative) reproduction is typical for marsupial fungi under optimally favorable weather conditions. Then, on the surface of the mycelium, conidia grow from ordinary spores (separated from hyphae) - immobile spores, ready to turn into a new organism with the functions of reproduction and settlement.

Reference: In the world of fungi, ascomycetes number more than 30,000 species. Their role in nature is not clear: they maintain the completion of the biological cycles of nitrogen and carbon, are the basis of lichens, and are included in the menu of invertebrates, rodents and even larger animals - wild boars and deer.

What folk remedies are there?

Most spots - yellow, brown, brown, red - are caused by fungal diseases. It doesn’t hurt to spray grape bushes with folk remedies - they are effective, affordable, and most importantly, safe for humans and the environment.

Popular folk recipes for spraying grape bushes:

• Potassium permanganate. Dilute 4 g of powder in 10 liters of water. You should get a pink solution.
• Milk. Dilute 1 liter of milk in 10 liters of water.
• Infusion of mullein herb. Pour 150 g of herb into 10 liters of water. Leave for 3 days.
• Laundry soap and soda. Mix 25 g of grated soap and 30 g of soda ash, and dilute the mixture in 10 liters of water.
• Wood ash. Pour 1 kg of raw material into 10 liters of water and leave for 5 days. Before use, add 20 g of soap, grated on a coarse grater, to the solution.

It is also recommended to prepare a decoction of tansy (medicinal plant). Take 300 g of crushed or dry raw materials and leave for 24 hours in 10 liters of water. And then boil for 2 hours. Cool and use undiluted infusion to water the soil.

Proper care and competent agricultural technology are the main conditions for preventing leaf spot. By promptly responding to signs of disease and regularly carrying out preventive measures, you will protect your bushes from diseases and protect yourself from crop losses.

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Description and photo of grape rubella

Grape rubella as a fungal infection. This disease of grapevines received its name from the color of the thickening spots that appear on the first leaves in May-June. So, why do grape leaves turn red? Sometimes, however, the nature of the spots can be completely different:

• mildew infection;
• damage to the plant by spotty necrosis (bacteriosis);
• spider mite damage;
• the presence of fluorine when fertilizing with boron superphosphate;
• noticeable potassium deficiency;
• heavy overload of bushes.

Rubella is characterized by color changes between the veins of the leaf, forming a triangular graphic; the leaves seem to rust. An indisputable confirmation of infection is the specific type of stain:

• in white varieties: grape leaves are covered with brown spots, with a narrow yellowish border, or completely yellow spots;
• colored varieties (pink, red, black) have dark red spots on the leaves of the grapes with a greenish-yellow outline around the edge.

The absence of sporulation on the reverse side of the leaf blade on the 2nd day of the appearance of the spot immediately excludes mildew infection.

Rubella is not an economically significant disease of grapes. It cannot be treated, since the fungus penetrates the vegetative organs of the plant. The parasite has the property of forming a persistent addiction to fungicides (chemicals). The fight against rubella is mainly about preventing the spread and changing the ecology of the environment.

Reference: The disease was first described by the Swiss biologist G. Müller at the beginning of the last century, who identified it in the vineyards of Thurgau (in the northeastern canton of Switzerland).

In the photo below you can get acquainted with the signs and appearance of rubella damage to grapes:

Infectious diseases of grapevine

Diseases of the bacterial and viral groups of grape diseases are caused by microscopic microorganisms - viruses and bacteria. They get inside the plant through the slightest cracks in the soil. The signs of such a disease are difficult to determine, and its consequences are as destructive as those of fungal diseases.

White rot

An infectious disease that occurs in grapes after sunburn or hail damage. Infects the fruits of the plant. They gradually turn brown and wrinkle, the clusters dry out and fall off. For treatment, spray with Fundazol or Colfugo Super. Depending on the spread of the disease, plants are sprayed 1 to 3 times.

Bacterial cancer

An infectious disease in which pathogenic bacteria enter the plant through wounds and cracks. Growths appear on the grapes—bole and sleeves—which are quite difficult to remove. To get rid of the disease, you should try to prune it heavily and rejuvenate the bush. If you cannot cure the vine, you should destroy the plant affected by cancer, preventing the bacteria from spreading throughout the garden.

Types of disease

Fruit growing specialists distinguish the nature of this disease, classifying it as:

• infectious;
• non-infectious.

In the first case, the vine during the first 3-4 years of life is affected by the transfer of spores from neighboring plants, including weeds and litter. In the second, the cause of the disease is:

• soil composition (rocky, poor in nutrients, in particular potassium);
• disturbances in the water balance in plant nutrition;
• weakening of the bush;
• prolonged rains;
• drought;
• low night temperatures.

Non-infectious rubella can be easily overcome by changing the entire agricultural background for the better or changing the feeding system.

Help: Systemic control of mildew can weaken the process of ascomycete infection.

White

The cause of white spots is oidium (powdery mildew.)

The causative agent of the disease is the grape uncinula fungus. It can affect grape bushes throughout the growing season. It affects young vines, leaves, inflorescences and berries.

The leaves on the bushes affected by the fungus are completely covered with a white coating, and it is observed not only on the outside, but also on the back side of the leaves. Under optimal development conditions (moderate humidity and warm weather), the mycelium grows so much that it covers the plant like a second bark.

The berries on the affected plants crack, and it seems as if the grains are about to fall out.

To combat the disease, chemicals are used: Topaz, Thiovit-Jet, Skor, Bayleton. Also today, combined preparations are produced that can protect grape plantings from both oidium and Mildew. These are Quadris, Storby, Cardio.

Among the folk methods, sometimes a milk solution (1 liter of milk diluted in a bucket of water), a 5% solution of potassium permanganate (5 g of manganese diluted in a bucket of water) are used to combat powdery mildew, which are sprayed with plants several times during the growing season.

Consequences

The introduction of a protozoan organism into the leaves, or, less commonly, grape clusters, leads to:

• thickening of the leaf plate and manifestation of its fragility: leaves curl and dry, until they are shed;
• changes in the productivity of the leaf as a photosynthetic apparatus;
• weakening of a plant that is not receiving enough nutrition;
• growth disorders;
• the appearance of deformed fruits that do not reach full ripening;
• reduction (up to 80%) or complete elimination of the harvest;
• re-infection at the end of the growing season (September).

Important: Grape blight, if not detected in a timely manner, can completely deprive the bush of leaves at the beginning of the growing season.

Black spots on grape leaves

Necrotic, almost black spots on grapes are a sign of Alternaria blight . The leaves darken gradually and become covered with a fungal coating over time. Alternaria blight affects not only the leaf blades, but the entire vine. A light metallic sheen appears on the berries. Hot and humid weather favors the development of the disease.

Control measures : spray the vine with 3% Bordeaux mixture or Trichoplant biological product (according to the instructions). As a preventative measure, remove all plant debris in the fall.

Black spots may be a symptom of excoriosis (black spotting) . Numerous dark spots appear in the internodes of shoots, on leaves and petioles. In case of massive damage, the shoots of the plant easily break and the grape bunches fall off. Excoriosis most often occurs in damp and rainy weather on dense, poorly ventilated plantings.

Control measures : remove fallen leaves from under the grape bushes, cut off and burn the affected parts of the plant. For prevention, before the buds open, treat the vine with a 1% solution of Bordeaux mixture. Repeat spraying after a week. Inspect your plants regularly. If signs of disease are detected, treat the grapes with a 1% solution of Bordeaux mixture.

Ways to combat the infectious form

What to do if red, yellow or brown spots appear on grape leaves, if the leaves rust? In fruit growing, there are three generally accepted ways to combat fungal diseases:

• chemical (using fungicides);
• biological (fungi do not tolerate competition);
• mechanical (agrotechnical measures).

But the most effective thing is to prevent the possibility of defeat.

1. The chemical method of combating plant diseases, at the current level of fungicide production, provides the highest efficiency and financial savings. The main condition: what is toxic to parasites should not be toxic to humans. Otherwise, the means do not justify the goal - the ripening of edible fruits that are beneficial for our body. Preparations for treating plants are:
   • contact type, directly affecting the affected surface (“ Rovral ”, “ Omite ”, Bordeaux mixture (8% solution);

   systemic type, when the drug is administered to penetrate all plant systems (“ Fundazol ”, “ Quadris ”, “ Strobi ”, “ Topsin-M ”, “ Topaz ”, “ Bayleton ”);

2. combined - combining properties of the first and second types (“ Ridom ”, “ Gold ”, “ Carbis Top ”).

In the fight against the causative agent of rubella, anti-mildew drugs work well: copper oxychloride (0.3% solution), polycarbacin, arceride, polychrome. It is no coincidence that where the vine was treated for downy mildew, the fungus does not manifest itself.

Chemical drugs have one disadvantage: pathogens get used to them, and a change in the synthesized substances or an increase in dose is required.

3. Biological means of combating fungal infections are non-toxic, but they also do not provide the long-lasting, lasting effect that gardeners expect. They are used mainly in the early stages of the disease, combined with traditional methods tested over the years.
   Very popular among biological products is the universal “Gaupsin", the effectiveness of which for all types of garden and vegetable plants, including grapes, is 90%. This is with complete safety of the drug for humans and other living organisms: higher animals, fish, bees. The effectiveness of its microflora is productive within 2 weeks, it does not accumulate in the plant, and does not affect the taste of the fruit. Keep " Gaupsin“Can be used in summer at room temperature for 4 months, in a cold place for up to six months.

   Biological agents also include the recommendation to treat bushes with a solution of wood ash extract and laundry soap (ash to water - 1/10; 50 g of soap). The frequency of treatment is once every 10 days, until the end of the growing season.

4. Mechanical means of control include:

• removal of affected leaves and shoots;
• removal of stepsons;
• chasing previously affected fruit shoots, leaving foliage above the bunches; stepsons in this case - do not delete;
• timely garter of shoots;
• destruction of pruning waste and dry litter;
• removing weeds from the root circle, digging up the soil;
• pruning the bush before winter;
• additional application of potash fertilizers.

Important: “Grapes love not sweat, but sun and earth.” The composition of the soil and the presence of potassium in it are very important for the health of the vine.

Reasons for decreased immunity in grapes

The weaker the plant, the more likely it is to get sick. Diseases and pests usually attack weakened plants. To prevent spots from appearing on grape bushes, it is necessary to grow them strong, hardy, and with increased immunity.

Why grape immunity decreases:

• planting weakened seedlings in waterlogged and poorly lit areas;
• violation of agricultural technology - incorrect application of fertilizers, ineffective spraying against diseases and pests;
• violation of pruning technology, errors in forming a trunk, allowing plantings to become dense;
• winter shelters for grape bushes are not properly equipped;
• heavy wintering, as a result of which the plant is weakened and frozen.

Grapes are most often affected by diseases in the spring, when the plants are weakened after wintering. If you do not immediately begin to fight the causative agents of fungal diseases, the spores will actively grow and multiply, affecting other grape bushes.

Prevention means

There are no specific preventive measures for rubella. This fungus appears earlier than the downy mildew pathogen, but is sensitive to preventative spraying against mildew. Here are a few rules to prevent this disease:

1. Both sides of the leaf must be treated with fungicides. In spring, it is better to use organic preparations, as copper can cause burns.
2. At the beginning of vegetative growth, it is necessary to exclude contact of the plant with old leaves.
3. It is recommended to monitor the lighting and ventilation of the bush.
4. After the initial treatment of young shoots and removal of infected leaves, you need to take care of sufficient leafing of the bush, reducing the length of pruning and maintaining healthy stepsons.
5. Qualitatively improve soil fertility by introducing organic fertilizers: manure, compost, humus.
6. Spray with potassium nitrate (1%) at the beginning or end of daylight hours (up to 5 times with an interval of 10 days), combining it with the application of potassium fertilizers at the root of the plant.
7. All grape pests (insects, birds), violating the integrity of the plant, open the “gate” for fungal infection. Prevention of ascomycetes includes protecting the vine from pests.

Learn about other types of grape diseases, types of rot, as well as how to detect and fight oidium, chlorosis, bacteriosis, bacterial canker and anthracnose.

Pest damage to grapes

Wasps

Wasps are common grape pests, and it is quite possible that you will find berries on your bush that have been bitten by them. Usually these insects do not finish eating the berries, and, having spoiled one, move on to the next, so even a small number of pests can ruin a significant part of the harvest.

Wasps are attracted to the sweet smell emanating from ripening grapes

Measures to combat wasps are as follows:

Destruction of a wasp's nest. This activity is best carried out in low light conditions (late evening, night or early morning), when insects are least active

Spray the nest with a poisonous substance (Dichlorvos, Raptor, Raid), after 20–30 minutes, carefully remove it into a closed container and burn it. Please note that for this event you need to wear tight clothing that completely covers your body and protect your face, for example, with a net. Using protective bags

If there is no nest nearby, then you can protect the grape clusters by putting special small-meshed fabric bags on them. The advantage of this method is that this way you will also save the grapes from birds. The downside is that the event is very labor intensive, so this method is best used in small areas with a small number of grape bushes. Making poison. You can place a flat dish next to the bushes with diluted honey or jam mixed with Regent or Aktara (1 g of product per 100 g of product).

Ticks

There are several types of mites that can cause damage to your grapes. Infestation by mites causes slow growth and development of shrubs, destruction of young shoots, and a decrease in the quality and quantity (by 20–50%) of the crop.

The main signs of this pest include the presence of red, silver and pale yellow spots on the outside of the leaves, and the possible appearance of membranes between the leaf and the stem.

The presence of small yellow peas on the leaves of plants indicates the appearance of spider mites

If you notice red swellings and bulges on the outside of the grape leaves, and brown spots on the inside, this means that there is a felt mite on your bush.

The main symptom of felt mite infestation of grapes is the presence of red raised rashes

Remove the affected leaves and shoots from the bush. Treat the grapes with the following preparations, especially paying attention to the inside of the leaf if you use them in the summer: Colloidal sulfur solution. Used when shoots grow 5 cm and at temperatures not lower than 20C

To prepare the solution, dilute 100 g of powder in 10 liters of water. Please note that this solution only affects adult insects, so carry out another treatment with a special preparation (Apollo, Neoron, Fitover) in the fall after leaf fall. Special preparations (Apollo, Neoron, Fitover), prepared according to the instructions. But keep in mind that it is not advisable to use them during the period of fruit ripening. DNOC. Used in spring (before buds open) or autumn (after leaf fall). Prepared in the usual way.

Red tick

If your grapes are infested with this pest, the leaves will take on a bronze tint. Treatment boils down to removing all affected leaves and treating the bush with a sulfur solution or a special preparation, as in the fight against other mites.

Phylloxera

Phylloxera, or grape aphid, is one of the most dangerous pests of grapes. An unpleasant feature of this pest is its rapid spread throughout the vineyard.

You can also fight phylloxera with the help of the drugs Fozalon, Kimnix (suitable for both types of phylloxera), Actellik. They are especially suitable for processing a small vineyard.

Is it possible to avoid the threat of infection?

The main condition for a healthy specimen in your garden will be a thoughtful choice of variety. After all, most European grapes are vulnerable to spore infections. And the beautiful “Cardinal”, and the basic rootstock “Queen of the Vineyards”, and “Muscat Hungarian”, and “Pearl of Saba” have only one weak point - susceptibility to fungal infections.

The creation of new hybrid forms using them, as a rule, is aimed at eliminating this drawback, at least partially. Therefore, in descriptions of varieties, you should always look at data indicating the resistance of grapes to any type of fungus, to high humidity, to low temperatures, soil fertility and characteristics of the density of a mature cluster. More often than others, the fungus attacks colored varieties and hybrids on “isabelle” rootstocks.

It is believed that among all types of vines, only black “winter grapes” (Vitis cinerea), growing in Texas, are guaranteed against fungal diseases, including grape rubella.

Dear visitors! We ask you to describe in the comments to this article your methods of treatment, control and preventive measures for grape rubella

Brown and brown

The appearance of brown and brown spots on the grapes indicates that the plant is infected with a fungal infection - anthracnose.

She infects:

• berries;
• inflorescences;
• shoots;
• leaves.

The first symptoms of infection of a shrub are brown spots with a rich dark color on the edges of the leaves. Then such specks increase in size and merge, and then “fall through”.

Cracks form at the sites of formations, and the shoots slowly die off. The pathology spreads to the grape inflorescences, which leads to a brown coating on the berries.

When the fungus infects the berries, they have visible brown inclusions with a black, dark or gray border. Control measures: before treating the plant with special chemical compounds, it is necessary to remove the affected parts and burn them.

To spray the bush you can use fungicides:

• 3% Bordeaux mixture;
• Fundazol;
• Polychomus;
• Previkur;
• Arcerides;
• Speed

The solution for use must be prepared according to the instructions supplied with the preparations. After 2 weeks it is necessary to repeat the event. Please note that the first spraying must be done when the shoots have reached a length of 10 cm.

The further procedure is 10 days before abundant flowering and the same number of days after it. After 14 days, repeat the treatment. Heavily infected bushes should be uprooted and burned.

For prevention, before flowering, spray grapes with 1% Bordeaux mixture and repeat treatments every 2-3 weeks.

Chlorosis on grapes: causes, signs and treatment

Chlorosis is a disease that is characterized by a change in the color of leaf blades. From green they become light green, yellow or whitish.

The color change occurs due to disruption of the photosynthesis process. There are infectious and non-infectious chlorosis. With an infectious form of the disease, several grape bushes or the entire vineyard can be affected.

The cause of non-infectious chlorosis is a lack of iron. In this case, the leaf blade of the bush turns yellow and sometimes acquires a creamy tint. The disease slows down the growth of the plant and can kill it.

Treatment of the disease includes spraying the bushes with specialized iron-containing preparations. Iron sulfate is used at home.

Causes of spotting

The appearance of spots on grape leaves is caused by many factors:

• improper care;
• fungal spores, of which there are countless;
• pests that feed on the plant.

Among the wide variety of grapes, there is no variety that can resist disease. Diseases whose symptoms include spotting:

• Alternaria blight;
• anthracnose;
• midyu;
• gray rot;
• oidium;
• black spot.

Hybrid varieties are also susceptible to damage if significant errors were made in care.

Symptoms of the onset of peptic ulcer disease

In order to recognize a dangerous condition in time and contact a specialist, it is important to know how trophic ulcers arise. Initially, a focus of increased pigmentation appears; the tissues darken due to the accumulation of hemosiderin, a product of the breakdown of hemoglobin.

After some time, a thickening of the skin and underlying tissues forms in the center of the dark area, the skin turns pale and shiny (white skin atrophy or pre-ulcerative stage)

Initially, a focus of increased pigmentation appears; the tissues darken due to the accumulation of hemosiderin, a product of the breakdown of hemoglobin. After some time, a thickening of the skin and underlying tissues forms in the center of the dark area, the skin turns pale and shiny (white skin atrophy or pre-ulcerative stage).

Gradually, the skin atrophies, cells die, plasma leaks through the walls of blood vessels, which permeates the tissue, forming edema. Burning and itching appears, the tissues become inflamed.

When scratching damaged skin, scratches are formed, and then an ulcer, the edges of which gradually widen and the bottom deepens.

The size of a trophic ulcer is from 1-2 ruble coins to 10-20 cm in diameter, with uneven edges. Ichor or blood appears on the surface of the wound. If a microbial infection gets into the wound, then pus, dirty gray or greenish deposits appear, and the wound begins to emit an unpleasant odor. The edges of the wound are inflamed, the tissue around is swollen. Any touch causes pain.

When healing occurs, bright red bumps and nerves—granulation tissue—form in the center of the wound. The edges of the ulcer shrink and the size decreases. The pain decreases, the surface of the wound dries out. With proper treatment, the ulcer heals completely, but later, if blood circulation is not restored, it may reappear in the same place or in another area.

In the absence of treatment, the area and depth of the ulcer increases, a perifocal inflammatory reaction of soft tissues occurs - acute indurative cellulitis, and secondary infection occurs with the development of local and widespread purulent-inflammatory complications i Kruglova L.S. Trophic ulcers of venous origin / L.S. Kruglova // Russian Journal of Skin and Venereal Diseases. – 2014. – No. 1. – P. 21-25. .

Non-infectious rubella

The cause of non-infectious rubella is a deficiency of potassium in the soil layer. If, due to a lack of nutrients, the weather is dry or there are sudden changes in temperature, then the leaves of the grapes turn red. Signs of this phenomenon include the following symptoms:

• the spread of the disease is observed immediately throughout the vineyard, and not on individual plants;
• redness and spotting appears immediately on all leaves on the vine;
• the veins of the leaf plates thicken and become very noticeable against the background of the leaf itself.

The cause of non-infectious rubella can be either poor soil or the presence of clay in it, which retains potassium. Perhaps the bushes do not have a sufficiently developed root system, which cannot provide the ground part with the required amount of nutrients from the deep layers of the soil. If treatment is not started in a timely manner, the plants die due to improper metabolic processes. When the first symptoms are detected, you must immediately spray the leaves with potassium nitrate. The procedure is performed early in the morning or in the evening after sunset. Spraying during the solstice will not give the most positive results. The drug will dry out very quickly and will not have time to exert its effect. To treat non-infectious rubella, five sprays are required, with an interval of 8 days between each procedure. Then, with the onset of autumn, a preparation of potassium sulfate or potassium chloride is added to the soil. Next year it is necessary to perform short pruning of the vines.

Insufficient soil nutrition

Another reason for spots on grape leaves is insufficient soil nutrition. Deficiency of iron, boron, magnesium leads to discoloration of the plant. A clear yellowing of the leaves indicates that the soil does not have enough iron or, on the contrary, there is too much lime in it. This deficiency can be eliminated by fertilizing with iron sulfate.

A few light spots on the plant may indicate that the soil is low in boron. To treat grapes, treat the soil with a 2% solution of boric acid.

Discolored leaf edges indicate a magnesium deficiency. To eliminate the problem, potassium magnesium should be added to the soil. In addition, you need to regularly hill up the soil to constantly replenish it with oxygen.

Preventive actions

The disease that has arisen cannot always be eliminated. Sometimes the appearance of a fungus or virus leads to the death of not only one bush, but also an entire crop. To prevent stains from appearing on grape leaves, you need to regularly carry out preventive measures.

Prevention of grape diseases includes:

1. Planting only healthy seedlings.
2. Planting the plant in a suitable area - without excess moisture and with enough sunlight.
3. Correct formation of bushes.
4. Timely sanitary pruning of vines, getting rid of diseased and dead bushes.
5. Planting disease-resistant plants.
6. Timely garter of bushes.
7. Treatment with antifungal drugs.
8. Preventive treatment with Bordeaux mixture.
9. Regular loosening.

Now you know why spots can sometimes appear on grape leaves. Unfortunately, almost always this sign is a harbinger of a dangerous disease. Taking preventive measures will prevent damage and death of grapes or reduce their risk.