Drying grape leaves: why this happens, how and what to treat

If the leaves on a grape vine begin to dry out, turn yellow, and fall off, this is a sure sign that the plant is in a depressed state and urgently needs to be saved.

First of all, it is necessary to determine the cause of the disease, because a correct diagnosis will help quickly restore the health of the grape plant.

Why are grape leaves drying out?

Grape – the plant is capricious. The slightest change in weather or environmental conditions will inevitably affect the shrub's development. There are many reasons why leaves may dry out, turn yellow, or blacken. However, changes in their structure can be caused by various factors.

Why do grape leaves dry out?

• diseases (both infectious and non-infectious);
• impact of harmful insects;
• lack of moisture in the soil;
• root damage;
• growing a variety that is not suitable for a given region;
• insufficient amount of fertilizers applied;
• violation of growing conditions.

Lack of moisture

Grape Although a southern plant, it cannot thrive in conditions of constant drought or without adequate moisture. The root system of a mature grapevine extends deep underground, reaching 80-100 centimeters in length. This means the soil must be well-moistened to this depth. If the roots don't receive sufficient water, they will stop adequately nourishing the above-ground portion of the plant, which will immediately affect the lush, green leaves. Leaves lacking moisture in their vessels will first dry out and then fall off.

Solution to the problem. If the first symptoms appear, water the vine immediately and then adjust the watering schedule. This moisture-loving plant requires watering at least twice a month, and during hot periods, increase the frequency to at least four times a month. Before flowering and during ripening, water the vine less frequently to prevent cracking. Moisten the soil to a depth of 80 centimeters. Water 20 liters per mature plant. It is recommended to water the vineyard at the roots using shallow furrows around the base of the plant. To prevent moisture from stagnating, loosen the soil after watering. Mulching the soil beneath the plants can help keep the soil moist for as long as possible.

Mineral starvation

During the growing season, grapevines require a lot of minerals. If they lack potassium, phosphorus, nitrogen, or micronutrients such as zinc, boron, magnesium, and others, the plant will stunt its growth, and the leaves will curl, darken, and dry out, inevitably leading to their fall. When grapevine leaves dry out at the very bottom of the vine, this most likely indicates a nitrogen deficiency. This condition can be observed in mid-summer. Leaf edges curling outward may indicate a potassium deficiency. Phosphorus deficiency causes darkening of the leaf veins. If left untreated, the leaves will wilt.

Solution to the problem.A simple supplemental fertilizer will help revive the grapevine and saturate the leaves with nutrients. If a lack of nitrogen is the cause of yellowing and wilting leaves, then it's necessary to feed the grapes with mullein or bird droppings diluted in water. Mineral supplements, such as urea or ammonium nitrate, can also be used. Potassium deficiency can occur during flowering and fruit set. During this period, it's recommended to perform an unscheduled spraying with potassium sulfate or treat the vines with a solution of iodine, baking soda, and water. If the leaves darken, indicating a phosphorus deficiency, superphosphate dissolved in water will quickly saturate the vines.

Violation of growing conditions

If a plant "lives" in uncomfortable conditions, it quickly stops growing and produces poor fruit. Its foliage dries up, the fruit wilts, and the flowers fall off en masse. Weather factors, such as insufficient light, can affect the health of the grapevine. In this case, the leaves first turn light in color and then dry out. Temperature fluctuations and excessive humidity also negatively impact the leaf blade.

Solution to the problem.Leaf wilting due to improper agricultural practices is the easiest to treat. Simply adjust the growing conditions, and within a few days, the leaves will return to their bright green, juicy glory. Since grapes wither without sufficient sunlight, they should be replanted in the sunniest spot in the garden. If grown in a greenhouse, supplemental lighting with phytolamps is necessary. Grapes require regular watering but do not tolerate excessive moisture—not only of the soil, but also of the air. Experienced gardeners recommend installing a tent over the vineyard during periods of frequent precipitation. When grown in a greenhouse, it's important to provide constant ventilation, maintaining air humidity at 60%. Sudden temperature fluctuations negatively impact the vines. Therefore, if frost is likely, mulching the soil is recommended to protect the roots from freezing temperatures. During hot days and when the temperature rises above +25 degrees, the grape bush should be sprayed with water and shaded from the scorching sun.

Diseases

Absolute majority diseases Immediately reflected in the foliage's appearance—it turns yellow and then dries up. If you observe this in your vineyard, it means the plant has been struck by a disease. It can be infectious or non-infectious (that is, not contagious). If the nature of the infection is identified in time, the vineyard can be saved and a bountiful harvest can be achieved. In addition to spraying with fungicides, it is also important to follow agricultural recommendations to keep the garden crop healthy for many years.

Diseases that cause leaf drying and methods of their treatment:

Verticillium wilt (verticillium wilt). A fungal disease of the roots. When infected, the roots stop properly nourishing the leaves, causing them to lose their succulence, become gnarled, and dry out. If the pathogen is not removed from the soil, the plant can die within two seasons.

TreatmentThe disease can only be treated in its early stages; after that, the plant cannot be saved. When a few sporulation spots appear, the bushes are treated repeatedly with Fundazol, with treatment intervals of 10-14 days.

Downy mildew. Fungal spores appear on the upper surface of the leaf as white, "shaggy" spots, which eventually turn black, turning the leaf blade into a dried-out stub. Berries and flowers also dry up and fall off.

TreatmentWithout intervention, the disease progresses very quickly, spreading from bush to bush, and the fungus can infect all garden plantings. Systematic spraying with complex fungicides such as Antracol, Kuproksat, and Delan will help suppress the infection. At the first signs of the disease, the vines should be immediately and thoroughly treated with the contact fungicide Hom, which will block the fungus from penetrating deeper into the plant tissue. Time-tested 1% Bordeaux mixture, Zineb, and Kuprozan also work well against downy mildew.

Chlorosis. The disease develops due to a lack of iron in the soil. Chlorosis is most often observed in carbonate, dense soils where nutrients are poorly absorbed. Chlorosis disrupts the formation of chlorophyll. This is why grape leaves turn yellow and then fall en masse. If left untreated, the vine will stop growing and die.

Treatment: Apply iron-containing preparations such as Antikhlorosin and Mikom-Reakom to the soil. Apply the treatment once a week until all symptoms disappear. Spray the bushes with ferrous sulfate (50 grams per bucket of water) every 4-5 days until they acquire a green sheen.

Gray rot. The infection thrives in a warm, moist environment. The fungus causes the affected areas to rot. The damaged areas gradually curl, dry out, and fall off the bush.

Treatment: If disease If the infection has already manifested itself, fungicidal preparations (Fundazol, Kaptan, Topsin M, Triadimefon, Topaz) are used to combat it. If the infection is weak, the bushes are treated with an aqueous solution of potassium iodide (2 grams of the substance per 10 liters of water) and copper sulfate (15 grams per bucket of water). Mikal, Folkan, and Antracol are used as protective agents.

Black spot. Once on the leaves, the fungus primarily affects the upper layers of plant cells. This causes the leaf blade to become discolored, and numerous small brown spots appear, which quickly enlarge, scorching the leaf. The leaf becomes gnarled, with holes of varying sizes appearing. Affected leaves fall off the plant. The disease can persist on a single plant for 4-5 years.

TreatmentSince the disease is long-lasting, it can be noticed before it has completely taken hold of the bush. First, remove all diseased shoots and pick off any damaged leaves. Then, treat the bush with a fungicide (Abiga-Peak, Cuproxat, or Bordeaux mixture). A single treatment won't cure the plant immediately; it will require years of spraying and a series of preventative measures to prevent the fungus from appearing. For example, ensure the bushes are well-tied and that the leaves don't touch the ground. It's also important to provide timely micronutrient supplements, particularly zinc and boron, which boost the plant's immunity to infectious diseases.

Alternaria. A hot climate disease. Leaves dry out at the edges, become covered with ugly yellow spots, and then fall off.

Treatment: To combat the disease, bushes are sprayed with mullein infusion and a potassium permanganate solution. A popular folk remedy is treating grapes with whey, to which iodine is also added. Among chemical treatments, Trichodermin is considered effective. More powerful treatments include Skor, Quadris, and Rapid Gold.

Dangerous pests

Almost all insects that feed on plant sap cause leaf diseases. Caterpillars, leaf rollers, aphids, spider beetles, and other microscopic creatures are particularly detrimental. Leaf curling and death occur when the larvae of the foamy leafhopper infest the plant. Their waste products (foamy secretions) block growth in the leaf, causing it to gradually die. The most common garden pest is the leaf roller. It feeds exclusively on leaves, sapping their vitality. A rapidly growing colony of spider mites can destroy a vineyard in a matter of weeks. Their web, woven from a fine mesh, envelops leaves and stems, causing thinning and rapid death.

Solution to the problemAccording to some gardeners, pests are easier to deal with than diseases. Various traps and baits are used against them, which significantly reduce insect populations. Folk remedies are most often used to combat various types of insects. For example, spraying plants with infusions of fragrant herbs (yarrow, marigold, dandelion) is very effective against caterpillars, mites, aphids, and other pests. garlic, onions), dusting the area under the bushes with ash or spraying the bushes with an ash solution. If the pest population has reached catastrophic proportions, chemical insecticides are used. Contact-and-intestinal products such as Akarin, Aktara, Actellic, Bi-58, Inta-Vir, Confidor, Tanrek, and others are effective against spider mites, leaf rollers, thrips, and aphids. These products are used according to the instructions not only to kill insects that have already reproduced but also as a preventative measure.

Root damage

If the above-ground portion of the plant has become unhealthy, the problem may lie in the roots, or more precisely, damage to them. Part of the grapevine's root system is located horizontally, close to the surface. Improper loosening, fertilizing, or digging can easily damage the root shoots. This problem is especially acute for young vines, which slow growth even with minor root damage. Mature plants tolerate wounds more easily; even a single root injury will not affect the overall health of the vine.

Root damage can occur due to inadequate winter protection. If the winter was cold and snowless, the unprotected root system can freeze. In summer, roots can be damaged by various rodents, such as moles, mice, and arthropods.

Solution to the problemIf the roots are not severely damaged and the vine is young, you can dig it up and remove the affected areas. Then soak the roots in a potassium permanganate solution or any antifungal solution. Before planting, soak the roots in a growth stimulator—this will promote rapid growth of new root shoots. Plant in loose, fertile, and moist soil.

If the roots of a mature plant are damaged, the area where the roots are located can be treated with a potassium permanganate solution or any antiseptic. It's best not to overwater the soil while the root wounds are healing to prevent rot.

Pestilence

Pathogens that cause infectious diseases can be carried long distances by wind, precipitation, contaminated equipment, animals, and birds. If one plant in a garden is infected, in most cases, the others become infected within the first week.

Solution to the problem: It's important to regularly inspect all plants in your garden for disease. If an affected bush is found, it should be removed from the area as quickly as possible—this will save time and effort in trying to restore the plant to health. It's wiser to sacrifice one bush than to risk the health of your entire garden.

Wrong choice of variety

Often, new gardeners, due to ignorance, plant varieties that are not suitable for the climate of a particular region. grapesIf a variety is recommended for cultivation in the southern regions, it will not thrive in the north of the country. And vice versa. A plant that lacks resistance to certain climate conditions grows weakened and vulnerable to diseases and pests. Such grapes will quickly spoil—the leaves will dry out, and the berries will be few and tasteless.

Solution to the problem:When choosing grapes for your garden, rely not on a pretty picture on the label, but on the description and characteristics of the variety. The manufacturer specifies the best growing conditions for a particular crop. If the grapes are recommended for greenhouse cultivation, don't expect spectacular results in open ground. For the central and northern regions of the country, it's preferable to choose frost-hardy, disease-resistant early grape varieties. For the south, varieties that can withstand prolonged drought, water stress, and poor soil fertility are suitable. Providing the plant with comfortable conditions can help avoid many health problems.

Prevention

Leaf wilting will bypass your vineyard if you properly implement preventative measures to keep the plant healthy.

Prevention Basics:

1. Plant your vineyard only in fertile, light soil. This will prevent chlorosis.
2. Do not fertilize dense soils with fresh manure and bird droppings, as this can lead to chlorosis.
3. Regular spraying of bushes with fungicides (Ridomil Gold, Cuproxat) will help prevent the appearance of fungus on plants.
4. Fertilize strictly according to the schedule, as plants react sharply to both a lack of fertilizer and an excess of it.
5. Be careful with watering. Don't overwater the soil.
6. In the fall, thoroughly clear the area of ​​plant debris and dig up the soil.

Conclusion

All the reasons listed above why leaves dry out grapes, will help you understand what to do and how to treat the crop to save the harvest. Maintaining the health of your grapevine is a daily task that requires both experience and knowledge from the winegrower. Growing varieties resistant to fungal diseases, such as Vostorg, Lydia, and others, can help reduce the cost. However, even these varieties require disease prevention, so it's important to always be vigilant and attentive to your grapes, regardless of the variety growing in your garden.