Black spots on the vine than to treat. We study grape diseases and ways to deal with them

The life of a summer resident is full of worries about household territory. A lot of trouble creates grapes - fruit crop, from which delicious wine, jam, juices are obtained. With special trepidation, the owner expects the harvest, because any factors can reduce its volume, from the shedding of the ovary to serious diseases. Measures should be taken immediately as soon as there is a problem of unformed or defective fruits, or the leaves become stained. Let's find out why spots appear on grape leaves, how dangerous it is and how to protect the nursery from damage to green mass.

Causes of vine leaf spot

The reason for the formation of spots on the leaves of grapes is always associated with a disease of the plant. Brown, white, yellow, red or black spots immediately catch the eye of the farmer. Against the background of healthy greenery, colored foci are easy to notice.

Among the common diseases of grapes, the symptoms of which are leaf spot and an unpresentable appearance of berries, experts distinguish:

The danger of having spots on the leaves for grapes is that they lure pests and fungal microorganisms. Pests pounce on varieties that give juicy delicious berries. Fungal colonies indiscriminately capture any weakened specimens. Plants lose their strength with insufficient care, improper pruning or warming for the winter.

Leaf spots are a common problem when growing grapes. As a rule, diseases are fungal in nature. If you let the situation take its course, the pathogens will remain inside the plant, survive the winter and make themselves felt in the new season.

Consider several diseases that summer residents most often encounter when growing crops, and give recommendations regarding therapeutic and preventive measures.

Mildew

Mildew distribution scheme
(Click on photo to enlarge)

Mildew disease is considered extremely dangerous for grapes. Its pathogen affects the green mass, shoots and ovaries. A sign of mildew are yellow spots on the leaves of grapes, located in the upper part. The lower part of the leaf is covered with a white powdery coating, which gives reason to call mildew false. powdery mildew. The fungus quickly spreads to healthy vegetation, because its spores are carried by the wind over long distances.

Infected grapes shed their leaves. Berries wrinkle, darken and rot. The disease weakens the bush and forces it to lose nutrient reserves. The plant overwinters in a weakened form and often dies.

How to deal with mildew? Farmers advise before bud break and before flowering, treat the grapes with Bordeaux mixture (1%) or such means as:

• Axihom.
• Kurzat.
• Polyhom.

Subsequently, spraying is preferably carried out every 14 days. If preventive spraying was not performed, the grapes are helped with the first signs of mildew. At a later date, the event becomes useless, since the spores of the pathogen move to the center of the leaf and become inaccessible to the drug.

Anthracnose

This disease affects the shoots, inflorescences, berries and leaves of the culture. But it is the grape leaves that suffer first - anthracnose appears on them as brown or brown spots with a dark outline. The affected parts of the plant dry up and become thinner, the berries dry out, the greens fall off.

For the treatment of anthracnose use:

• Arcerid.
• Polyhom.
• Copper chloride.

Before spraying, the diseased parts of the grapes are cut and burned.

Bordeaux mixture is used to prevent anthracnose. The first time to process the bush is necessary before flowering, using a 3% concentrate. Re-treatment is carried out after flowering with a one percent mixture.

oidium

Oidium - infection scheme
(click to enlarge photo)

When grapes are sick with oidium, its leaves may become covered with grayish-ash spots. White hearths as if sprinkled with flour. In addition to the leaves, true powdery mildew affects the inflorescences, fruits and shoots of the crop. Affected greens wither and fall off, berries crack, release grains to the surface of the skin and rot if it is too humid outside.

The simplest prevention of oidium is pruning, which provides air flow to all parts of the shrub. It is also useful to engage in loosening row spacing.

If you notice white spots on the leaves of grapes, decide immediately how to treat the plant. In the absence of special preparations, use a solution of colloidal sulfur (90 g of the substance per bucket of water). From ready-made funds, buy Topaz, Acrobat MC, Carbis Top, Thiovit-Jet, Skor, Bayleton.

Alternariosis

The cause of Alternariosis is the intolerance of dry weather to the grapes, which causes silvery or brownish spots to appear on its leaves, and a film and plaque form on the berries. White spot located in the center of the grape leaf, but gradually it darkens and becomes moldy. It is customary to treat grapes for alternariosis with Trichodermin. The first treatment of the bush is carried out in the spring. Preventive drugs Rapid Gold, Skor and Quadris are used throughout the season 2 times a month.

grape mite

The initial stage of the development of the disease "grape mite" is similar to the symptoms of mildew. Fluff without bulges helps to differentiate mildew from a tick. With a weak infection with a tick, only the lower leaves of the grapes deteriorate. In advanced cases, the disease affects the upper greens. The leaves on the grapes gradually turn pink or red.

Treatment with the following preparations helps to protect the nursery from grape mites:

• Aktara.
• Bi-58.
• Karate Zeon.
• Vermitek.

Wilt

Verticillium wilt of the shrub occurs gradually. The fungus provokes the drying of leaves in a young vineyard, which is planted on the site of a former strawberry plantation. Leaf veins turn brown. A light yellow space separates them from the green part. Berries wrinkle and rot.

Methods for the treatment of wilt disease have not been developed. Occasionally, the plant recovers on its own.

Spots on grapes: causes and treatment

When only the green mass of grapes deteriorates during a disease, the summer resident has a chance to save the bunches and get a harvest. If spots appear on the berries, it will not be possible to save them. The plant must be treated and protected from adversity with preventive actions.

Gray rot

The disease affects only the fruit part of the crop. At first, grapes may become covered with dark brown spots. Then they wrinkle, burst and ooze. At the next stage, the surface of the fruit acquires a gray putrefactive coating.

What to do if spots of gray rot appear on the grapes? In dry weather, the clusters can be used to make homemade wine, as hot conditions naturally increase the sugar content of raw materials.

chemical fight with rot lies in the preventive spraying of grapes in early spring. For this, Antrakol, Mikal, Folpan are used. A diseased plant is treated with such means as Topaz, Ronilan, Topsin M.

white rot

Infectious disease affects fruits affected by sunburn or beaten by hail. Grapes become brown and wrinkled. If the clusters dry out, they fall to the ground and infect neighboring seedlings. To prevent the spread of white rot, the grapes must be treated with Fundazol and Colfugo Super. If the plant is sick repeatedly, spraying is done 3 times.

aspergillus rot

The disease develops in hot weather, but rot can also occur during storage of the crop. At first, light spots are observed on the grapes, but then the foci become depressed, cracked and black.

Grapes are saved from Aspergillus rot with fungicides and preparations containing copper. Disease prevention is spring pruning bushes and processing sections with copper sulfate or Bordeaux mixture.

Spots appeared on the leaves of grapes - what to do and how to treat

yellow spots on vine leaves

Yellow spots on grapes most often appear when the plant is attacked by a common disease such as mildew (downy mildew). Yellowish spots are localized on the upper side of the leaf blade, and on the reverse side you can see a whitish powdery coating. Mildew infects the whole plant and quickly passes to neighboring specimens, since it is able to be carried by the wind. Soon the leaves of the grapes die off and fall off, and the berries darken and shrivel.

Mildew often affects grapes of European varieties.

Control measures: spray the vine with drugs Arceride, Kuprikol, Delan, Hom, Kurzat. For prevention, before bud break and flowering, and then every 2 weeks, treat the grape vine with 1% Bordeaux liquid.

Brown and brown spots on grape leaves
Brown spots on grapes are usually a sign of anthracnose, a fungal disease. In this case, the edging of the spot has a darker color than its core. Soon the entire leaf darkens and then falls off. The stem is also covered with brown spots, some time later rot develops in these places. Anthracnose progresses with high humidity. If the disease passes to the stalks, then the berries quickly fall off.

Control measures: spray the bushes with 3% Bordeaux liquid or Polich, Arceride, Previkur, Skor, Fundazol preparations (according to instructions). Repeat after 14 days. Heavily infected bushes uproot and burn. For prevention, before flowering, spray the grapes with 1% Bordeaux mixture and repeat treatments every 2-3 weeks.

White spots on vine leaves
Light (white, grayish and ashy) spots on grapes are a symptom of oidium (powdery mildew). The leaves gradually dry out and fall off. The fruits are also covered with a light gray bloom.

This fungal disease more often occurs with dense plantings. Therefore, for preventive purposes, it is important to carry out competent pruning vines.

Control measures: when 3 leaves appear on the shoots, treat the bushes with a solution of colloidal sulfur (90 g per 10 liters of water). Repeat after flowering. Three times during the growing season, pollinate the grapes with sulfur (2 g per 1 sq.m.). For the treatment of oidium, use the preparations Hom, Kurzat, Ordan, Topaz, Planriz, Fundazol.

black spots on vine leaves
Necrotic, almost black spots on grapes are a sign of Alternaria. The leaves darken gradually and eventually become covered with a fungal coating. Alternariosis affects not only sheet plates, but the whole vine. A light metallic sheen appears on the berries. Hot and humid weather favors disease development.

Control measures: spray the vine with 3% Bordeaux liquid or Trichodermin biopreparation (according to instructions). As a preventive measure, remove all plant debris in the fall.

Black spots can be a symptom of excoriosis (black spotting). Numerous dark spots appear in the internodes of the shoots, on the leaves and petioles. With a mass defeat, the shoots of the plant break easily, the grape clusters fall off. Excoriosis most often occurs in wet and rainy weather in dense, poorly ventilated plantings.

Control measures: under the vines, remove fallen leaves, cut and burn the affected parts of the plant. For prevention, before bud break, treat the vine with a 1% solution of Bordeaux mixture. Repeat spraying after a week. Check your plants regularly. If signs of disease are found, treat the grapes with a 1% solution of Bordeaux mixture.

Red spots on grape leaves
Red spots on grapes most often appear due to non-compliance with the rules of cultivation. In this case, the plant is attacked by rubella.

It can be both infectious and non-infectious. The disease often manifests itself with a lack of potassium, prolonged drought and low air temperatures.

Control measures: apply potash fertilizers to the soil, treat the bushes three times with 1% potassium nitrate. Spray the plants early morning or late in the evening.

Also, red-brown spots on the leaves of grapes of colored varieties can appear when the plant is damaged by a spider or felt mite.

In white grape varieties, in this case, yellow spots form on the leaves.

And if bumps appear on the upper side of the leaf blade, and pink or brown pubescence on the lower side, then the plant was attacked by grape itch (phytoptus).

Control measures: During the growing season, spray the vine with acaricides (Neoron, BI-58, Confidor, colloidal sulfur, Amitraz, Pyridabene). In the fall, remove all plant debris.

Rusty spots on vine leaves
yellowish brown and rust spots on grapes can signal plant disease with rust. At the same time, orange fungal spores (in the form of pads) are visible on the spots.

Control measures: treat plants with Strobi fungicide (5 g per 10 liters of water). Repeat spraying after 10-14 days.

Black spot (Phomopsis viticola Sacc., escoriosis, phomopsis, shoot death), a long-known fungal disease of the grape bush, was named for the characteristic signs of the disease on the shoots and leaves.

The picture of the disease

Black spot is noticeable from June, primarily on the nodes of annual shoots of grapes in the form of black-brown to black, round or oval dots. Under a microscope, they look like swellings of bark tissue, on top of which a dead and browned stomata can be seen. Below it is a focus of necrotic cells in the form of a bag or lens. As the vegetation progresses, most of the dots increase, often merge into elongated spots that open in the middle and become light brown in the central part. The darker edges of the gap corky and give the affected areas a scab-like appearance. As a rule, only the first 6-7 internodes are affected. Often the lowest leaves are also infected, less often the tendrils and crests of bunches of grapes. Even flower caps are sometimes covered with black spots. On the affected leaf blades, oval and angularly outlined necroses are visible, mostly near a more powerful vein, which here is superficially or completely colored black. Leaf necrosis is surrounded by a light border of compacted tissue. Due to the tension of the tissue, curling of the leaf blade and, eventually, tears and holes are often observed. Severely affected leaves turn yellow prematurely. Ripening berries are sometimes also affected, turning dark purple and unpleasant in taste. In autumn and winter, the annual wood of grapes along the entire length, or only at individual internodes, or near the lower nodes, turns whitish-gray. On discolored areas of the bark at temperatures above 10 ° C, fruiting bodies of the fungus are formed, at the bases of which small black pustules are visible. Under the bark of perennial wood, fruiting bodies can also be found growing to free, cartilaginous black formations and sometimes overlapping each other. If the mycelium grows deep into the wood, then rotten areas are formed, which first weaken the growth, and later cause the death of entire sleeves.

The causative agent and the development of infection

In spring, at temperatures above 8 ° C and the presence of a water film over their excretory openings, pycnidia emit white and yellowish antennae, which can contain up to 1 million spores stuck together with each other. In rain or heavy dew, the masses of spores spread and spread partly with water droplets or, after drying, also by wind, insects and some mites. Phomopsis produces two types of spores: oval to fusiform alpha spores with normally developing hyphae and filamentous curved beta spores that form only rudimentary germ tubes; their functions are not yet known. The ratio of alpha and beta spores varies greatly. Some pycnidia contain spores of only one form or the other. If the spores fall on the green parts of the bush, they germinate already at a temperature above 1 ° C and a relative humidity of at least 86%, resulting in a new infection.

The spread of the fungus inside the vine bush can occur due to saprophyte growing mycelium, capable of starting growth at a temperature slightly above zero, and spores that are transferred by rainwater from the pycnidia of fruitful shoots to the bark of the sleeves and trunk or to cracks and crevices in the wood.

Measures to combat black spot

Chemical control with the currently known active substances against the mycelium of the black spot fungus, which grows rapidly under the protection of the host tissues, does not give results. Therefore, it should be directed against the fruiting bodies of the fungus, and especially against scattered and spreading spores.

In case of severe damage, after a thorough cleansing pruning, timely winter spraying with DNOC, dinoseb or copper preparations is carried out, and the first two spraying agents are more effective. Winter processing it must be supplemented in the spring after the beginning of the growth of grapes when the first leaf appears, by treatment with one of the organic fungicides; the treatment is repeated when 2-3 leaves unfold, and then carried out every 10 days until the start of the fight. We also recommend the last treatment as early as mid-August, at the same time also directed against grapes.

As a rule, with a weak defeat, it is enough to start the fight only at the beginning of spring growth. Since, apparently, it is impossible to completely eliminate black spot in a short time, even with repeated thorough winter and spring treatment, it should, at least in case of severe damage, fight for several years.

Although economically satisfactory control of the disease is only possible with fungicides, some maintenance agrotechnical measures are nevertheless of particular importance. These include: strict pruning of diseased vine shoots after leaf fall, using only healthy shoots as fruitful wood whenever possible, burning all cut shoots in the vineyard as soon as possible, excluding all infected wood from planting material production, meticulous green operations and a balanced supply of nutrients. in the vineyard.

BLACK SPOT OF GRAPES
DISTRIBUTION, HARMFUL, PROTECTION METHODS

Among the diseases of perennial wood on vineyards, the most common is black spot, or phomopsis. The causative agent of black spot is the imperfect fungus Phomopsis viticola (Phoma) Sacc. (class - Deuteromycetes Deuteromycetes (Fungi imperfecti), family - Spheropsid Sphaeropsidaceae).

Among the diseases of the trunk and shoots, black spot is the greatest threat. At present, the disease is common in all viticultural countries of the world, but it is most harmful in areas with high humidity air. It affects not only varieties of Vitis vinifera, but also American rootstocks. With the intensive development of black spot, the bushes die in 5-6 years. With severe black spotting of vegetative and generative organs, up to 50% of the crop is lost. Due to the insufficient accumulation of plastic substances, the resistance of plants to unfavorable conditions is also weakened. winter conditions. Therefore, the development of the disease during the growing season in combination with the freezing of perennial wood in winter is especially dangerous.

The disease is spread by mycelium during pruning, by mycelium and pycnospores during the growing season and from planting material. If the vines harvested for propagation were affected, then the disease develops intensively in the school, sharply reducing the yield of seedlings, and then transferred to the vineyards being planted.

The fungus overwinters in infected buds or last year's ridges in the form of mycelium, on annual and perennial shoots (including trunks) in the form of mycelium and forms pycnidia on the surface of the bark. In spring, at temperatures above +5 ... + 8 ° С, after prolonged wetting of shoots, spores form in pycnidia and spread by raindrops (mites and insects) to shoots, leaves and inflorescences. Pycnidia mature throughout growing season, therefore, the probability of infection of the vegetative and generative organs of the bush exists almost constantly. However, most often the infection of leaves, ovaries, ridges and shoots occurs in early spring (before the formation of the 6th leaf) and during flowering. The spread of the fungus inside the grape bush can also occur due to the growing mycelium, capable of starting growth at temperatures slightly above zero.

In years characterized by heavy rainfall during bud break, as well as cool periods that inhibit the growth of shoots, the development of black spot is especially intense and the disease causes significant damage to the vine plant.

The causative agent of black spot develops in the temperature range from 5 to 40°C. However, infection can also occur at lower temperatures, as black spot spores can germinate at 1°C. At low temperatures It may take up to 30 days from the moment of infection to the appearance of the first visual signs. The optimum temperature for the development of the fungus is between 20 and 25°C. In this case, the duration of the incubation period is reduced to 8 days (with average daily temperature 10°C - 15 days). With prolonged (more than 6 hours) exposure to 29-30°C, the formation of conidia is inhibited, and at 35-37°C, the death of the mycelium begins. Conidia are able to germinate at air humidity from 25 to 100%, however, the most favorable humidity is in the range of 50-80%.

The etiology of the disease is complex. Features of the biology of the fungus make it difficult to diagnose and therefore the manifestation of signs of black spotting is often confused with damage to the leaves by ticks, and the bark - damage by pathogens of various diseases (in particular, the causative agent of spotted anthracnose).

characteristic feature manifestations of the disease during the growing season:
- the formation of steep or oval red-violet (to black) spots, spreading along the shoot in the phase of 3-5 leaves. The formation of black spots is caused by the death of the cells of the epidermis and the underlying tissue of the cortex. Sometimes the spots merge and ring the shoot. On the affected branches at the base, wide nodules are formed. The bark cracks as the shoots grow, sometimes irregular cavities are formed from this, which in some places penetrate to the very wood. Most often, annual shoots are affected up to the 6-8th internode. However, with the intensive development of the disease, the entire surface of the annual vine is covered with ulcers, necrotic spots and cracks, deep necrosis appears on the wood. On the lower, usually heavily affected internodes, up to 60% of the buds die, which reduces the load on the eyes and promotes the development of shoots at the end of the fruit arrow, where they easily break off. Affected shoots with a strong development of the disease can dry out completely.

The fungus continues to develop on the surface of the shoots even after their lignification. An important diagnostic sign of plant damage by black spot is the coloring of the wood of the lower internodes of annual shoots in a whitish-gray color. Numerous black dots - pycnidia of the fungus - form on the affected areas of the bark in autumn and spring. Pycnidia are also formed under the bark on perennial wood (stem and sleeves). If the development of the disease occurs for several years in a row, then the dormant eyes of perennial wood are damaged, which leads to the absence of shoots in the upper part of the stem and at the base of the arms - the plant becomes bare. There is such a phenomenon as "dry sleeves", or "death of sleeves". The disease is most dangerous when the affected shoots are used to form boles and sleeves of perennial plantations (in case of their death).
On leaves, symptoms appear in May-June as several small dark brown or chlorotic spots (with a black center) with a greenish-yellow border along the veins. Due to the uneven tension of the tissue, the leaf blade acquires a wavy shape (curly), after a while the affected leaf blade “swells up” and cracks. In dry weather, the affected tissue dries up and eventually falls out. Severely affected leaves turn yellow prematurely and fall off completely. Leaf deformation weakens photosynthesis. The lowest leaves are most often infected, less often tendrils and crests of clusters, which can cause them to fall off.

The symptoms of black spot on the leaves can be confused with leaf damage by the Phyllocoptis mite (Calepitrimerus vitis). If you look at the leaves inhabited by grape leaf mites in the light, then small yellowish spots are clearly visible, while when black spot is affected, the center of the spot is painted black. Through a magnifying glass, you can see how the veins of the leaf converge to one point - the place where the tick sucks.

Necrosis in the form of spots and dots is also observed on the ridges, inflorescences and tendrils, which leads to their premature drying.

Sometimes ripening berries are affected, which subsequently become dark purple and unpleasant in taste, shrivel and rot. On the surface of the berries, pycnidia are formed in concentric circles. Infection of berries can occur throughout the growing season, but in most cases during flowering or within 2-4 weeks after flowering. At first they acquire a light brown color, then they become dark purple. Pycnidia mature under the epidermis.

Symptoms of the disease on leaves and shoots appear 3-4 weeks after infection. Signs of infection of berries, ridges and combs remain latent (imperceptible) throughout the growing season almost until harvest.

Practically stable; there are no European grape varieties to black spot. The least susceptible are Bastardo Magarachsky, Italy, Merlot, Silvaner, Rose Traminer, Augustine, Moldavian Black, etc. Susceptible varieties are Cabernet Sauvignon, Aligote, Dove, Chasselas, Sauvignon green, Semillon, Chardonnay, Aivaz, Dessert, Karaburnu, etc.; very susceptible - Rapture, Cardinal, Muller Thurgau, Zhemchug Zala, Odessa Muscat, Chaush, Northern Saperavi, Hamburg Muscat, Madeleine Angevin, Shabash, Rose Taifi, Queen of Vineyards, etc.

PROTECTION METHODS
To protect against black spot, a complex of agrotechnical and chemical measures. The stock of the pathogen is reduced by careful removal and burning of severely affected parts of vines. The development and harmfulness of the disease are hindered by agrotechnical measures that improve the conditions for the growth and development of bushes. This is a timely garter of shoots, removal fruitless shoots, making balanced nutrients fertilizers and the use of trace elements, in particular and.

The intensive development of black spot in almost all viticultural zones of the world was provoked by a decrease in the proportion of copper-containing (or complete rejection of them) and the use of organic compounds to protect against mildew (downy mildew). Due to the effectiveness and ease of application of organics, the first spraying in vineyards began to coincide with the appearance of visual signs of development of mildew, which did not allow to contain the early spring spread of primary black spot infection.

The optimal scheme for protecting grape plants from black spot (with a strong development of the disease in previous years) includes early spring treatment with copper-containing fungicides or 1% BZ. However, it should be noted that this treatment, carried out before bud break, is effective against pycnidia (blocks the germination of spores), but is completely ineffective against mycelium remaining in dormant buds and on shoots. The next spraying should be carried out on swelling buds or during the period when the "flag leaf" is advanced by 40-50% of the buds. If necessary, repeat spring spraying carried out in the phase of 4-5 leaves (shoot length 5-7 cm).

When carrying out the first preventive treatments, contact fungicides are usually used to reduce the risk of primary infection of plants. Mainly copper-containing preparations; fungicides with active substance folpet, folpet + triadimenol, captan, mancozeb. dithianon, propineb, etc.

After the flowering of grapes, treatments against black spot are usually combined in terms of timing and set of preparations with protection against downy mildew.

" Grape

Although grapes are an unpretentious culture, despite this, they require some care. One of these activities is the prevention and treatment of diseases. By breeding new grape varieties, breeders are working on this problem, however large-fruited varieties those with high sugar content are still susceptible different kind diseases. To receive annually high yield the grower 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 crop are:

• mildew;
• alternariosis;
• cercosporosis;
• armillariasis;
• oidium;
• chlorosis;
• rubella leaves;
• septoria;
• escoriosis.

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 vine bush, it can infect the entire vineyard in a short time. At the initial stage, it manifests itself in the form of light yellow-oil spots, the size of a penny coin on young foliage. On older leaves, the spots are angular and parallel to the veins.

At further development on the back of the leaf, a mycelium appears in the form of a white fluffy coating. If the weather is warm with high humidity air, a fungal infection rapidly spreads to the tops of young shoots, mustaches, affects inflorescences and recently set fruits.

This type of fungal disease is formed in summer period in leaf plates, where it survives wintering well.

Fungus spores are activated at a temperature of +10 degrees. Most favorable conditions for instantaneous distribution 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 the spores do not germinate.

Vine leaf affected by 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 site for growing grapes;
• autumn mulching between rows;
• proper shaping of the vine to ensure good breathability;
• timely pruning of excess shoots;
• removal of weeds under bushes and between rows;
• drainage or drip irrigation;
• top dressing with mineral fertilizers;
• starting from the spring, prophylactic treatment with Bordeaux mixture every 10 days.

Alternariosis disease

Alternariosis, or olive blotch, affects the leaves of grapes as a result of high humidity. It appears in the form of spots on the back and an olive-gray coating. With the active development of the fungus, the leaves dry out, curl.

This type of fungal disease also affects the fruits. When they are stored, the fungal infection spreads to healthy brushes, affecting them. On fruits, the fungus manifests itself in the form of cracking and changes in the taste of berries. The shoots affected by a fungal infection do not mature and do not tolerate wintering. The spores of the fungus overwinter on infected shoots, fruits and upper layers soil.

Alternaria on vine leaves

The necessary preventive measures are:

• timely pruning of infected processes;
• removal and burning of weeds and dry leaves;
• feeding;
• treatment with copper sulphate and Bordeaux liquid.

The beginning of the defeat of Alternariosis of grape berries

Terms of preventive measures:

1. During the period from March 21 to April 12 after tying the vines, spray with copper-containing preparations.
2. April 24 to May 9 treat with a biofungicide. You can use the drug "Trichofit" for these purposes.
3. May 16 to June 1 treat with the drug "Kvadris". Continue processing every 14 days until the initial stage of berry ripening.
4. From August 15 to September, after harvesting, prune the vine and burn it.
5. From October 20 to November 10 it is necessary to rake out the fallen leaves and treat the soil and the vine with copper-containing preparations.

It should be treated with sprayers from the bottom side. When processing the top surface of the sheet, there will be no results.

Cercosporosis and how to deal with it

Given fungal disease affects leaves, shoots, stalks and fruits. First of all, foliage that is close to the ground is affected, since the sun's rays do not penetrate well into this part of the bush, and increased 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 defeat by the fungus, grape bushes bear fruit poorly, worsen taste qualities fruits, the vine does not reach maturity.

It appears as an olive coating on the underside of the leaves. Over time, brown spots appear on the surface of the leaf, with a light touch, the leaves fall off.

Affected berries are covered with an easily washable olive coating, become hardened and fall off when touched.

Preventive measures necessary to prevent the disease:

• mandatory pruning of grapes twice per season;
• deep digging between rows in spring and autumn;
• watering 4 times per season;
• weed removal;
• spraying bushes in autumn and spring with a 1% solution of Bordeaux mixture;
• mandatory support.

• spray infected bushes every two weeks with fungicides;
• burn infected leaves.

Armillariasis affecting the roots

This disease is a fungal infection that develops on the roots of a plant. The infection infects the roots of grapes, penetrating into the bark and releasing toxic substances, killing living tissues, after which it develops on infected cells. Spread by fungal spores. The spores are extremely toxic and can kill an infected plant. Typically, infection occurs in spring period, and in autumn yellow mushrooms grow on the bush.

For the development of this disease, there must be increased humidity and 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 it on this place new seedlings throughout 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 of this disease is its rapid development at high air temperatures - above +31 degrees.

The first symptoms of the appearance of Aspergillus rot on grapes. 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 coating, then dark depressed spots. The skin in these places is pulled together and cracked. The pulp 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 spores of the fungus;
• 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, the shoots of the inflorescence. When affected, the inflorescences do not develop and do not ripen. This disease lives and progresses only on living cells. Winters in bark cracks and on buds.

Spores, falling on the leaves, multiply rapidly, carried by the wind. Exceptional conditions are high humidity (more than 80%). Depending on the temperature regime the incubation period lasts from a week to two weeks. A favorable temperature for the rapid development of the 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 plaque that appeared on the clusters and flowers resembles flour;
• shoots are covered with dark spots;
• dead areas appear on the processes.

Prevention measures are as follows:

• digging the soil, cleaning foliage and weeds;
• top dressing with phosphorus-potassium fertilizers;
• processing 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 when there is 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 manifests itself in the form of spots on sheets of bright lemon color. The shoots stop developing, and the leaves dry up and fall off. The fruits become small and do not reach maturity. A weakened bush may not survive the winter.

Prevention of this disease is the treatment of bushes with the drug "Chelate".

Grape leaves affected by chlorosis acquire a rich lemon hue

rubella leaf

In late spring or early summer, grape bushes can become infected with this fungal disease. It affects grape leaves damaged by insects.

It is possible to determine the infection of a bush with rubella by the following signs:

• sheets in the lesions have spots in the form maple leaf covered with a rusty coating;
• 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 by a yellow border;
• in dark varieties, the spots are bright red.

To avoid infection you need:

• process the leaves with a Bordeaux mixture;
• carry out regular pruning of bushes;
• rake and burn fallen leaves;
• apply fertilizer to the soil;
• dig aisles.

Septoria

Characteristic for nutmeg varieties grapes. Appears as small brown spots on sheets. If the humidity is high, mold will form on the underside of the leaves. When it dries, it falls off and spreads 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 grow moldy and dry out

Escoriosis disease

Escoriosis is a dangerous fungal disease that affects all parts of the plant. Represents black spots on the leaves and shoots of the bush. Spread most rapidly 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, treatment with Bordeaux mixture can be applied.

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:

• mandatory application of fertilizers containing zinc and boron;
• timely formation of a bush;
• removal and burning of affected parts;
• using healthy seedlings for planting.

To protect the vineyard from diseases, it is necessary to observe the conditions for growing grapes and take timely preventive measures to prevent the spread of infections. It is recommended to plant those varieties that are most suitable for growing in this region.