Protection of grapes from fungal diseases
- Part 1. Grapevine born to give immortality
- Part 2. Features of vineyard care
- Part 3. The vine must suffer. Pruning
- Part 4. Protection of grapes from fungal diseases
- Part 5. Protection of grapes from pests
- Part 6. Vegetative propagation of grapes
- Part 7. Grape propagation by grafting
- Part 8. Groups and grape varieties
Infectious diseases are caused by specific fungi, viruses and bacteria. As a rule, they settle on living tissues and, accumulating in the plant, lead to its death. From the affected plant, wind, rain, untreated tools, pathogens are transferred to healthy bushes. Gradually, the infection accumulates in the soil and fallen leaves and, if not taken protective measures, can destroy the entire crop.
The most malicious fungal diseases of the vine that can destroy the crop in a short time are mildew, oidium and other types of rot (gray, white, black). No less infectious are bacterial cancer, black spotting and about 500 other infectious diseases of various pathologies.
Signs of defeat mildew
Mildew, peronosporosis or downy mildew - all three names of one of the most dangerous fungal diseases. Under suitable weather conditions, infection occurs before flowering or during the mass flowering phase of the vineyard. The disease quickly affects all parts of the vine bush. The overwintered spores of the fungus are carried by wind or rain spray and at a temperature of +11 ºС begin to grow into the internal tissues of the bush.
The longer the wet weather lasts at a high positive temperature, the shorter the incubation period and within a week an epiphytotic lesion of the aerial mass of grape bushes can begin. The lower part of the leaves, inflorescences, berries are covered with a white powdery coating, and on the upper side the disease is manifested by light green spots, at first the size of a penny coin. Quickly growing, mycelium captures the entire leaf surface. She switches to young shoots, which gradually dry up, the berries shrink and fall, the bush dies. In favorable weather (damp and warm), the fungus forms up to 20 generations during the growing season, causing a massive spread of the pathogen. The natural attenuation of the disease, but not the death of the pathogen, occurs in hot weather.
Mildew is a disease for the most part of European varieties of southern vineyards. In landings of the northern range, peronosporosis does not occur on its own, but appears as a result of the purchase and landing of material affected by the fungus. Therefore, do not forget to disinfect purchased seedlings before planting and always sanitize tools. It should be noted that today many new varieties advanced northward in the non-chernozem zone of the Russian Federation, Moscow Region, Belarus, and some other republics with a fairly cold climate are being defeated by mildew. Moreover, mildew is even affected by varieties in which the stocks are Vitis labruska and Vitis amurenzis, resistant to this disease.
Signs of an oidium lesion
Oidium or powdery mildew - The most common fungal disease that affects the living organs of a plant. Pathogen mycelium hibernates in the kidneys, on shoots, cracks in the bark, in fallen leaves. Symptoms of the disease appear first in the form of a dirty gray coating of different consistency on the upper side of the leaves, leaf vein necrosis, later oily touch spots with a pronounced smell of rotten herring appear. The whole plant is gradually covered with a soft coating of a characteristic gray-ash color, for which the people call this disease an “ashtray” (ashen).
In the southern regions, the pathogen begins its destructive work with the onset of heat and dry weather, affecting the buds, young shoots and other organs of the plant. In the northern regions, the manifestation of the disease begins later at an air temperature of +20 - +25 ºС, and the development of the pathogen is characterized by increased aggressiveness and affects the whole plant in a short time. Inflorescences and young clusters completely die.
For its development, the oidium needs (unlike mildew) in high temperatures and dry air. Rains inhibit the development of the disease. Affected bushes reduce yield and product quality. Grape varieties completely resistant to oidium have not yet been bred. Even products partially affected by the disease are not suitable for the production of wine. Therefore, oidium, like mildew, is considered a particularly dangerous disease.
Signs of rot
Grapes get sick with other types of fungal rot (white, gray, black), the harmfulness of which is manifested mainly by the disease of berries.
- Gray rot develops after prolonged wet weather. It in the form of a mouse-shaped mold covers the ripening berries, without affecting, green, containing large amounts of acids.
- Black rot (like gray) develops after rain. Separate brownish spots appear on the green berries, and brown spots surrounded by a black border appear on the leaves. The spots on the berries gradually merge, staining them in purple. Over time, the berries turn black and fall.
- White rot manifests itself in hot dry weather in the form of a change in the physical condition and color of ripening berries in places of sunburn. Mostly black varieties are affected. At first, the berries become lethargic, then they turn slightly brown (as if starting to ripen) and fall off.
Measures to protect the vineyard from disease
Protection measures can be divided:
- for preventive
- active, which include biological and chemical methods.
A vineyard cannot be protected from diseases by once spraying not only with a separate preparation, but also with a tank mixture that destroys several types of pathogens at once.
There are no effective drugs against some fungal diseases. The most effective method is prevention, that is, a proactive effect on the source of the disease.
- Plant the vineyard only with zoned varieties with high resistance to disease and weather extremes.
- Carry out all agricultural activities and procedures in a timely manner, in the morning and evening hours, which will protect vegetative shoots and berries from the harmful effects of sunlight.
- Keep the soil under the vineyard clean. In autumn, remove all fallen leaves, the remains of broken off stepsons and other waste in which the pathogen overwinters. After trimming and other operations, be sure to carry out a complete cleaning of the waste, and disinfect the used tools.
- Do not overfeed the bushes. When applying fertilizers, it is better to use their balanced mixture.
- Watering is carried out only under the bushes in a moderate stream without spraying and water falling on the aboveground part of the grape.
- Given the need for a humid environment for the spread of most fungal diseases, do not allow planting to thicken. Conduct all green operations in a timely manner (stepsoning, lightening, and others).
- To protect against diseases, using literature and practical recommendations, develop a system of measures indicating the time and method of processing the bushes. Do not get carried away with chemicals. Remember - a home vineyard must provide the family with environmentally friendly products.
Biological protection measures
Biological measures to protect the vine from disease include the use of biological products (harmless to human health, animals, beneficial insects) and effective microflora (EM bacteria).
- Saprophytic microflora treatment. In early spring, concentrate is prepared from humus. The mature humus is sieved and filled with 1/3 of the barrel per 100 l, topped up with the full volume of heated water (+25 - + 30 ° C). The solution is kept for about a week. During this period, saprophytic fungi multiply and are able to compete with pathogens for food. The resulting concentrate is carefully filtered through several layers of gauze or other material, so as not to clog the sprayer, and sprayed during the growing season in the morning or in the evening once every 8-10 days, starting from the buds phase and until the brushes are brushed. In total, 5-6 sprays are performed. This measure does not kill the pathogen, but significantly inhibits its development and allows you to get environmentally friendly products.
- The use of working solutions of the concentrate "Baikal EM-1". In winter, the EM-1 stock solution is prepared from the concentrate, which is used to prepare working solutions. Working solutions EM-1, EM-5 and others must be used on the same day. The best time for spraying is in the morning on dew or in the afternoon (after 16-17 hours). Spend in April first spraying a working solution of bushes and soil with an EM-1 solution at a concentration of 1: 500 (2 ml of stock solution is used per 1 liter of water). When buds open second spraying vines and soil under vine bushes. The soil is sprayed with a solution, where 10 or 4 ml of the basic preparation is diluted in 1 liter of water per 1 liter of water (1: 100-250). Immediately by hoeing, the solution is embedded in the soil in a layer of 5-6 cm. For bushes, a less concentrated solution (1: 500-1000) is used or 2 or 1 ml of the base is diluted in 1 l, respectively. In the budding phase and until the end of July, and sometimes when harvesting 1 time in 3 weeks, the vine is treated with a working solution of EM-5. To dilute the solution using 1-2 ml of the base drug per 1 liter of water (1: 500-1000). For processing usually prepare 10-20 liters of working solution, trying to thoroughly sprinkle the underside of the leaves. If the disease (or pests) multiply very quickly, then the concentration of the working solution is increased to 1: 250. They are sprayed with bushes daily for no more than 3-4 days and are transferred again to low concentrations. Be careful! High concentrations inhibit crop formation.
- If the vineyard includes literally 5-10 bushes, you can apply another way to preserve the quality of berries from damage by rot. At the end of the peeling phase, the onset of ripening 2-3 times with an interval of 7 days, spray the bushes with a 10% solution of milk or whey. On large areas, the use of the solution is expensive and does not always provide the expected effect.
- From biological products, especially in cold wet spring, it is possible to recommend Bionorm-V, Novosil, Valagro, Albit, Narcissus and others for processing vines.
The use of chemicals
Processing of grapes from damage by pathogenic fungi begins in early spring at the onset of air temperature of +10 - + 13 ° C and ends no later than 1.0-1.5 months before harvesting.
- In the spring, before buds open and in the fall after harvest, bushes and the soil under them are systematically sprayed with a 3% solution copper or iron sulfate.
- Before flowering, after flowering and before the fruit ripens, spraying is repeated every 2 weeks with a 1% solution Bordeaux fluid or its substitutes. Be sure to repeat the treatment after rain and irrigation. Bordeaux fluid is an effective and most widely used harmless drug, but it does not treat diseased plants and does not kill the pathogen, but only prevents the disease. Therefore, along with Bordeaux liquid, it is necessary to use bio- and some chemical preparations, the latter being better in the first half of the plant vegetation. So, before flowering, you can treat the bushes with 0.2-0.3% solution of Ditan M-45 or 0.25% solution of Ridomil. The preparations Ridomil Gold MTs and Shavit are complex and have a strong effect on several types of rot, including oidium, mildew, and gray rot. Strobi, Topaz, Bayleton preparations well inhibit the development of the disease.
When using chemicals, be sure to focus on the annual permit lists. Naturally, all chemicals must be used with all personal protective equipment and the health of family members. Prepare and use solutions in accordance with the instructions. It is possible to reduce the load on the vine by treating with tank mixtures of drugs that affect not only diseases, but also pests of grapes.
- Part 1. Groups and grape varieties