Vine leaf diseases with photographs. We talk about all types of diseases on grape leaves. Mildew and ways to deal with downy mildew

Should we calmly contemplate how the leaves turn yellow and become covered with holes, how almost ripe berries fall off, or can all this be overcome? Of course you can, if you know the enemy in person.

Knowing the diseases of grapes, descriptions with photographs and methods of treatment, the most dangerous and highly contagious, you can easily carry out preventive treatments, as well as therapeutic ones.
It is more practical to consider diseases of grapes starting from the most common ones, those that have covered the continents and moved even to the most distant islands.

Diseases of grapes photo and how to treat

Mildew

It is also called "downy mildew". Experienced growers say "There are grapes - there are mildew." However, not all grape varieties with the same intensity are affected by this enough. dangerous mushroom. The wintering phase of the fungus is spores. In the soil, fallen leaves, mulching material, they perfectly tolerate both frost and heat. But for reproduction, the fungus needs moisture, regardless of the temperature regime. In one season, a harmful fungus can give up to 15 generations. But, as soon as the temperature drops below 12ᵒС, reproduction stops.

Looking closely at the leaf, you can see yellow spots, and on the reverse, inner side, these spots are covered with a fluffy fungus. Over time, these spots dry out, and a hole forms in their place.

Not good beautiful picture and on berries. The stalk, and the berry itself is covered with a white coating of the fungus. Over time, the berry crumbles.

For the treatment of vines against mildew, Ditan M-24, Acidan, Rapid Gold, Mancozeb, Acrobat MC are applicable - all these preparations contain the active substance mancozeb. The preparations "Ridomil Gold" and "Ridomil" have a detrimental effect on the fungus with a substance called metalaxyl. On the basis of chlorine copper oxide and tsinab, Tsikhom was created.

Grapes are planted, diseases and the fight against them, seeing such a list of drugs, are no longer so terrible, but they must be applied comprehensively, regularly, and in a timely manner.

For preventive purposes, in order to prevent rampant mildew, you can easily use copper-containing preparations, for example, Bordeaux mixture.

Biological preparations such as Alirin-B, Planriz, Delan will also give an excellent effect against the fungus.

grape mite

The initial stages of this disease are sometimes very similar to mildew. But in the case of a mildew lesion, there is only a “fluff” without bulges, so they are easy to distinguish.

With a small infection, only the lower leaves are affected, if measures are not taken, then spread to the upper leaves cannot be avoided. The bumps become pink and reddish over time. Sometimes the berries are affected, they are covered with felt, as it were. The tick is especially rampant in hot weather.

Treatment with preparations "Bi 58", "Vermitek", "Aktara", "Karate Zeon" significantly reduces the population.

oidium
But this disease is no longer false, but real powdery mildew. When the fungus is rampant, the leaves of the grapes become, as it were, sprinkled with flour. This mushroom does not like hot climates, it likes more moderate temperatures. The fungus covers the leaf completely both from the outside and from the inside. Sporulation of the fungus occurs constantly, during the entire growing season. During this time, the fungus grows and covers grape leaves and grony like bark. The berry cracks, and the grains seem to fall out of it.

This disease cannot be left to chance. Treatment not carried out this season will increase the virulence of the fungus in the future. Processing grapes from diseases, in particular from oidium, is not only the salvation of this year's harvest, but also the salvation of the vine itself. Using the drugs: "Topaz", "Thiovit-Jet", "Skor", "Bayleton" according to their instructions, you can significantly improve the mycosis background and restore the plant.

If you treat the grapes with Quadris, Cabrio, Strobi preparations, then this will be a fight with both mildew and oidium.

Alternariosis

Brown and silvery spots covering leaves and shoots, sometimes acquiring a metallic sheen, are the work of Alternaria fungus. In wet weather, the plaque becomes olive in color. Sometimes the fungus appears as small, dark brown spots, the spots increase and merge. The same spots affect the shoot. Young leaves and shoots are most susceptible to damage. If last season you had this disease of grapes, in the spring, it is imperative to process grape bushes copper-containing preparations, and with the appearance of the first signs, you can apply "Skor", "Kvadris", "Rapid gold", "Cabrio-top", "Colfugo super".

Anthracnose

Suspicion of this disease falls when the young leaves of your grapes appear small brown spots surrounded by a black border, this pattern resembles a bird's eye, which is why this disease is sometimes called this disease. The center of this "eye" eventually becomes gray or white, dries up and perforates. The fruits are also affected, the same spots appear on them, over time the fruits crack.

At the first signs, it is necessary to use any of these drugs "Skor", "Ridomil", "Arcerid", "Acrobat". Multiplicity of processing 12-14 days.

bacterial cancer

A bacterium brought into your vineyard with seedlings or equipment, having settled in the bark, begins its rapid division. The bark cracks, forming peculiar influxes. disease on this moment does not have reliable methods of protection. It is fashionable to attempt treatment with hydroxy tetracycline, but the method has not been proven to be effective. The vine must be destroyed. At the place of growth of the affected grapes, quarantine measures are carried out for four years.

Gray rot

Looking at the photos of grape diseases, you will immediately make a diagnosis. Both berries and other parts of the plant are affected by gray rot. Sometimes it looks like natural rot, but with the deterioration of weather conditions, the fungus begins to spread so quickly that the pathogenicity of the pathogen becomes obvious.

The disease is difficult to treat, but using the drugs "euparen" or "fundazol" you can slightly stop the process.

verticillium wilt

Sometimes this disease is called "wilt". The wilting of the bush occurs gradually and ends with the drying of the leaves and death. The fungus retains its virulence in the soil for many years. A young, 4-5 year old vineyard planted on the site of a strawberry plantation is especially affected.

Treatment methods have not been developed. Sometimes cases of self-recovery are possible.

white rot

Diseases of grape berries (photo) description may not always accurately convey. But looking at the photo, you can immediately determine that it was the white rot mushroom that “sat down” on your berries.

White rot begins to rage, usually at the end of summer. In appearance, the berries become as if scalded. High air temperature and humidity contribute to the very rapid spread of fungal infection. Contributes to increased infection mechanical damage, hail. Therefore, the means of struggle must be applied immediately after the end of bad weather.

By applying the preparations "Kolfugo Super" or "Fundazol" you can stop the spread of the fungus.

Mildew, or downy mildew, is the most common and dangerous disease of the vine, requiring the annual application of a chemical control method.

In years with a damp, rainy lot, a significant part of the crop perishes from it, and if protective measures are not applied correctly, collective farms and state farms can completely lose their crops.

This disease was brought to Europe from America. It was first discovered in France in 1878.

In Russia, mildew appeared first in Bessarabia (1885) and the Caucasus (1886), then in the Crimea (1891) and on the Don (1895). In the following time, the disease quickly spread to other places. Within the limits of the USSR, this disease can cause significant harm in all viticultural regions, with the exception of the republics of Central Asia, where, although it is noted, it cannot develop due to the hot and dry climate. Unfavorable conditions for the development of mildew also exist on the southern coast of the Crimea and in some regions of the Armenian SSR. Only in 1954 and 1955. on the southern coast of Crimea, a massive appearance of mildio was noted, due to unusually rainy weather in the summer.

The causative agent of this disease is a microscopic fungus (Plasmopara viticola Berl et de Toni), which affects all green parts of the bush: leaves, inflorescences, clusters, shoots, tendrils. On leaves affected by mildew, yellow, slightly translucent, so-called "oil" spots appear. On the underside of the leaf, the spots are covered with a white, easily erased coating. In the future, the spots turn brown and dry. With a severe defeat of the leaves, their plates fall off the petioles and the bush in the summer can completely lose the leaves.

The same white coating forms on the inflorescences as on the leaves. The buds and flowers dry up and fall off. Often, the entire inflorescence dries out from mildew.

The tied berries, when their mildew is damaged, have a dirty grey colour and in wet weather they become covered with bloom. They easily come off the comb. On older berries white plaque can not be. Usually they form dirty bluish depressed spots, mainly. at the place of attachment of the berry g, the peduncle. The pulp turns brown, the berry shrivels and falls off at the slightest shock.

Longitudinal brown spots appear on green shoots, which in wet weather become covered with a white bloom. Often, the entire upper part of the shoot, located above the affected area, dies off and detaches at the node.

The white plaque formed on the affected organs is the sporulation of the fungus. It consists of colorless, branched conidiophores, 250 to 800µ long and 8-12µ thick. The branches are located almost at right angles. The terminal branches are short, tooth-shaped. They form colorless, ovoid spores - conidia.

Bundles of conidiophores come out of stomata, located mainly on the underside of the leaf, as a result of which a white coating of the fungus forms on its lower surface. The same stomata are present on inflorescences and young berries, which is why a white coating appears on them in wet weather. In berries the size of a pea or more, the stomata overgrow, and therefore a white coating does not form on them.

With the help of wind, insects and rain, conidia are carried around the vineyard. They can only grow in a drop of water. Therefore, a new infection occurs only during rain, dew or fog. During germination, the protoplasm of the conidia breaks up into separate lumps, which exit the conidia through the hole formed by this time. Lumps of protoplasm move in water with the help of two flagella. These motile bodies are called zoospores. After some time, the zoospores stop above the stomata and are drawn into the germ tube, with the help of which they penetrate through the stomata into the tissues of the green organs of the bush. Berries, in which the stomatal gaps are overgrown, do not become infected. If conidia get on the stalk, where there are stomata, fungal threads can penetrate the berry and cause infection.

Fungal filaments that develop in the intercellular spaces of the tissues of the vine absorb nutrients and water from the cells with the help of special suckers - haustoria. A few days later, summer sporulation of the fungus appears in the form of a white coating on the lower surface of the infected leaf from the stomata. During the lot there are several generations of the fungus, and the more, the more often it rains and dews.

In autumn, round wintering spores develop inside the affected organs (most often leaves), the so-called oospores, which have a thick brown shell. With the help of oospores, the fungus overwinters. In the spring, winter spores germinate. A tube grows from the wintering spore, at the end of which a conidia of the same shape as the summer one, but only larger, appears. It is called macroconidia. In water, mobile zoospores emerge from macroconidia, which cause the first infection of mildew vineyards.

The harm caused by mildew is very great. The disease causes premature mass shedding of leaves, as a result of which the shoots are exposed. When clusters of mildew are affected, whole bunches or individual berries die off, which crumble in bulk.

In severely affected bushes, the normal course of all physiological processes (assimilation, respiration, evaporation, etc.) is disturbed, which weakens the plants and leads to poor maturation of the vines. Therefore, heavily affected bushes have poor resistance to adverse winter conditions. Wine obtained from berries heavily affected by mildew is of poor quality.

In the spring, the leaves are the first to become infected. The fungus can infect both adult and young leaves. The oospores found in leaves shedding in autumn are able to overwinter both in depth and on the surface of the soil. They germinate in the spring after the rain falls. For oospores to germinate, it is necessary that the soil remains moist for several days after precipitation (2-8). Germination of winter spores of the fungus can occur at temperatures of 11-38°C. The warmer the spring, the sooner the oospores germinate. So, at a temperature of 17-25 °, winter spores can germinate from a light rain that wets the soil surface for 2-3 days; in cool weather, longer soil moisture is necessary, for example, at 14 ° - at least 5, and at 11 ° - at least 8 days.

Infection of grape bushes with mildew can occur only during rain, dew or wet fog, since the exit of zoospores from macroconidia and summer spores is carried out only in drops of water. After infection, the hyphae of the fungus penetrate the tissues of the plant along the intercellular spaces and after a few days a yellow “oily” spot appears on the infected site, which is covered with a white fungal bloom, which is the summer sporulation of the fungus. The formation of summer sporulation occurs at night with high air humidity (95-100%) and a temperature not lower than 8 °. Spores that have just arisen can immediately germinate and produce a new infection.

The latent period of time (i.e., the period from the moment of infection to the appearance of sporulation of the fungus) is called the incubation period. K. Muller found that the duration of the incubation period depends on temperature:

If at the end of the incubation period there is dry weather, then it will drag on until rain or dew falls at night, which ensures the formation of sporulation of the fungus.

A. S. Msrzhanian and A. D. Lipetskaya (1936) established that for the development of the mildew pathogen during the incubation period, the biological zero is a temperature of 7.9 °, i.e., only at this temperature does the development of the fungus begin. Moreover, the sum of active temperature degrees (above 7.9°C), which ensures the development of the fungus from the moment of infection to the formation of sporulation, is 61°C.

With the onset of dry weather, especially accompanied by winds, sporulation and infection of vines stops, conidia quickly die. However, the mycelium of the fungus remains vital inside the affected tissues and, when precipitation falls and grows, again forms abundant sporulation. Fresh conidia germinate immediately.

The degree of development of mildew in vineyards largely depends on the location of the site and the care of the vines. The most severely affected vineyards are located in low, damp areas, poorly blown by the wind, in dense plantings, as well as in vineyards where green operations, tying and weed control are carried out untimely and of poor quality. When applying nitrogen fertilizer, the development of the disease increases, while potash fertilizers increase the resistance of the vine against mildew (Moser).

While all European vines are susceptible to mildew, there are more resistant varieties that need to be sprayed less often. The resistance of varieties largely depends on the environmental conditions of the grapevine. In the southern regions of the Ukrainian SSR, the varieties most resistant to mildew are: Aligote, Silvaner, Senso, Portugizer, Riesling; less resistant: Chaush, Zant, Black Crimean. In the Krasnodar Territory are more stable: Semillon, Clairette. On the contrary, Portugieser here is strongly affected by mildew. In Transcaucasia, the most resistant varieties are: Mattress, Rkatsiteli, Saperavi, Kumsitetri, etc.

Control measures. Selection of healthy planting material. Growing vines on trellis formations that provide better ventilation of the bushes and are more accessible for high-quality spraying. Deep plowing of vineyards in autumn or early spring. Cutting and removal from the vineyard of vines with signs of damage, as well as the immediate removal of green mass after breaking, pinching and chasing. Careful and timely removal of root suckers, the leaves of which are primarily infected with mildew in the spring. Timely garter of green shoots, as well as fragments, pinching and chasing. Maintaining black fallow in the vineyard throughout the growing season. Application of phosphorus-potassium fertilizers.

Of the chemical methods of control, the most common and effective is spraying the bushes with 1% Bordeaux liquid. When using ground-based equipment with economic tips that reduce fluid consumption by almost 3 times, the concentration of Bordeaux mixture is increased to 3%. When spraying vineyards with the help of aircraft, 5% Bordeaux liquid is used at a solution consumption rate of 250 liters per 1 ha.

Instead of Bordeaux liquid, vineyards can be sprayed with a 0.5-0.8% suspension of copper chloride when using ground equipment, or a 3-5% suspension when applied by aircraft. To protect the bunches from mildew, additional dusting of the bushes with copper chlorine oxide is done, and it is better fixed when dusted by dew.

V. N. Kornilova (1956) recommends that, to protect the brushes, the first spraying with 3% Bordeaux mixture be carried out at a time when the inflorescences grow enough and the lobules begin to separate from the main axis, but are not yet closed or are just beginning to be covered with leaves. This period occurs approximately 10-12 days before the grapes begin to bloom. In this case, in her opinion, a stock of fungicide is created on the inflorescences, which provides long-term protection of the crop from mildew damage.

In years of mild development of the disease, Bordeaux liquid can be replaced with a 1% suspension of dinitrorhodanbenzene with copper oxychloride. According to V. A. Alymova (1956), with heavy rainfall, dinitrorhodanbenzene with copper oxychloride was strongly washed off and therefore, in terms of efficiency, it was significantly lower than 1% Bordeaux liquid. AT foreign literature it is recommended to use organic preparations captan and ditan against mildew.

In 1955, testing of a new, aerosol method for combating mildew began. Aerosols are able to penetrate deep into the bushes and, enveloping them, settle in a thin and uniform layer on all parts of the bush, including the brushes and the lower surface of the leaves, which is very important for a successful fight against the disease. To obtain aerosols, a 20% solution of copper naphthenate in solar oil was used.

Since the infection of leaves with mildew occurs through stomata "located mainly on the lower surface of the leaf, when spraying it is necessary to cover not only the upper, but also the lower part of the leaves with a solution.

Spraying used against mildew is not a therapeutic, but a preventive measure that protects healthy parts of the bush from infection. Therefore, the chemical method of control will only be effective when spraying is carried out in a timely manner, before infection with mildew.

Since during the summer there are several generations of the fungus and more and more new leaves grow on the vine, several sprays are carried out, 4-6, and sometimes more. The more often it rains and dews, the more spraying is needed.

When determining the timing of spraying against mildew, two methods are used: 1) by incubation periods, 2) by the growth of new leaves. To establish the timing of spraying by incubation periods, it is necessary to conduct meteorological observations of air temperature, precipitation and dew, as well as the time of the appearance of the first spots and the subsequent development of the disease in the vineyard. Observations begin to conduct from the moment the leaves bloom. If, after the appearance of the leaves, it rains, which will cause a wet state of the soil surface for 2-3 or more days at a temperature not lower than 11 °, then it can be assumed that the winter spores have germinated and the first infection of the leaves has occurred.

By determining the average daily air temperature at the time of the rainfall, one can determine the day when the oospores germinated and infected the leaves.

After establishing the day of the alleged first infection, the time of the possible appearance of the disease is calculated by comparing the average daily air temperature and the duration of the mildew incubation period at this temperature. By the time mildew is expected to first appear, the vineyards should be sprinkled.

Regular inspections of the vineyards are carried out to check the accuracy of the estimated time of occurrence of the disease. Such observations should be made on last year's foci and on low areas of the vineyard.

After the appearance of mildew, the average daily temperature sets the time for the second and subsequent manifestations of the disease. Sprayed either in each incubation period or after one period if they are short (4-5 days). Spraying during flowering or immediately after it is especially important, since the ovaries that have dropped the corollas should not remain unsprayed. 1% Bordeaux liquid does not adversely affect the setting of berries, and therefore it can be safely used during the flowering of the vine.

When setting the timing of spraying by incubation periods, you can also use the sum of degrees of effective temperatures (61 °), as mentioned above.

With the second method of determining the timing of spraying vineyards, the first treatment is carried out in the spring when 4-5 leaves appear and it rains. In dry spring, the first spraying is done before the flowering of the vine. When determining subsequent sprayings, they are guided by the weather conditions and the rate of growth of new leaves unprotected by the poison. During the period of intensive growth of the vine (May, June) and in the presence of wet weather, spraying is repeated with the growth of 4-5 new leaves (every 8-10 days). With weak growth of the vine (July, August) and dry weather, it is sprayed with the growth of 6-7 new leaves in about 12-14 days. Spraying is stopped 3-4 weeks before harvest.

Both methods of setting the timing of mildew spraying are not perfect and need to be clarified.

The method of determining the timing of spraying by incubation periods is complex and requires regular observations of outbreaks of mildew and the organization of own meteorological installations on farms or well-established communications with the nearest meteorological stations.

In addition, the actual appearance of mildew does not always coincide with the expected one, due to the inability to determine in advance the temperature conditions during the incubation period. According to Oltarzhevsky (1955) and Milossavlievich (1950), the incubation period increases at low minimum or very high maximum temperatures, which is observed in regions with a continental climate.

The age of the leaf and varietal characteristics also have some influence on the duration of the incubation periods (Kondarev, 1953; P. M. Shterenberg, 1956). In addition, the incubation periods with frequent dews overlap, due to the fact that the spots sporulate not once, but over several days. This makes it difficult to establish the timing of spraying.

The method of determining the timing of spraying by the growth of new foliage unprotected by the preparation is simpler and accessible to each farm. However, when using it, one must also monitor the development of the disease in order to avoid unnecessary treatments or, conversely, not to be late with spraying.

During the summer, from 3 to 6-8 sprays are carried out, depending on the development of mildew. Grape school is sprayed every 8-12 days. Liquid consumption when spraying shkolki 300-800 liters per 1 ha. From 600 to 1500 liters are spent on spraying adult vineyards, depending on the density of plantings, the formation and strength of the growth of bushes.

AT last years I. M. Polyakov (1956) and Yu. V. Gorinova (1956) develop new method mildew control by spraying the soil with solutions of various preparations to kill winter spores. These eradicating sprays are carried out during bud break, between the rows, without trapping soil in the rows (to avoid damage to the eyes). Eradication sprays are made with new poisons manufactured by the All-Union Plant Protection Institute, preparations No. 47, 78, 125 and rhodan. Liquid consumption 800 l per 1 ha. According to I. M. Polyakov, eradicating spraying with these preparations not only destroys the stock of infection, but also increases the yield of grapes. Eradication sprays provide an opportunity to reduce copper consumption. This method of mildew control needs further study.

oidium

Oidium (powdery mildew, ashes, sack) was brought to Europe from America along with planting material. Within Russia, this disease was noted for the first time in the Caucasus (1848), then in Bessarabia (1852) and in the Crimea (in 1853) - subsequently, oidium quickly spread to other areas of viticulture.

Among grapevine diseases, oidium ranks second after mildew in terms of severity and degree of distribution, and in some places, for example, on the southern coast of Crimea and in Central Asia, this disease even has paramount importance. Here, in some years, up to 50-80% of the crop perishes from oidium. Significant development of the disease is also observed in the viticultural regions located along the coast of the Black and Caspian Seas, as well as in many places of the Georgian, Armenian and Azerbaijan SSR. In these areas, it is necessary to conduct a regular fight against oidium every year.

In most of the regions of Ukraine, Moldova, the Rostov region, as well as in the Stavropol Territory and regions of the Krasnodar Territory remote from the sea, oidium is found only on individual foci, and it is not controlled in all vineyards.

However, large-scale irrigation works carried out in the Rostov Region, as well as in the Stavropol Territory, which make it possible to irrigate large areas of vineyards, can change the microclimate so much that it will become possible development oidium.

Oidium can develop on all green parts of the grape bush: inflorescences, clusters, leaves and shoots.

Affected inflorescences are covered with a grayish-ashy bloom, dry out, and then fall off. Most often, the oidium affects the berries, on which a powdery coating forms, emitting a specific smell. On the skin of the berry, under the coating, numerous dirty gray dots appear, the totality of which looks like star-shaped spots - irregular outlines. In places of damage, the skin stops growing, as a result of which it cracks under the pressure of normally growing tissues, and the seeds are exposed. In wet weather, cracked berries rot, in dry weather they dry out. Thus, a significant part of the crop dies. Wine obtained from affected berries is of low quality.

A gray, slightly noticeable coating also develops on the sheet, which can be located on both sides of it. Powdery coating covers the sheet either in a continuous layer or in the form of separate rounded spots. Often on the upper side of the sheet appear round yellow spots, slightly reminiscent of the "oil" spots of mildio, but only less pronounced. Leaves severely affected by oidium stop growing, dry out and fall off. On older leaves, under a powdery coating, dirty-brown spots of irregular shape form.

On green shoots under a gray coating appear the same as on the leaves, brown, irregular shape spots that remain visible even after lignification of the vines. In case of development of oidium on shoots in early period growing season (for example, in May), the shoots covered with bloom soon stop growing and are underdeveloped until the end of the year.

The causative agent of this disease is a microscopic fungus (Uncinula necator Burill.), which settles on the surface of the green tissues of the bush and feeds on its juices. When examining a gray plaque under a microscope, one can distinguish thin creeping mushroom threads that are attached to the green organs of the vine with special suction cups. On these filaments erect cylindrical conidiophores develop, slightly widened in the upper part. At the ends of the conidiophores, oval or barrel-shaped colorless spores appear in chains.

From the movement of air, spores easily fall off and are carried by the wind. They can germinate both on the surface of water droplets and on unmoistened leaves, berries, and shoots. The most favorable conditions for the germination of conidia are relative humidity of 70-95% and temperature of 16-25°. In general, the germination of spores can occur in the range of 5-33 ° and at any relative humidity observed in nature. A few days after spore germination (most often after 4-6 days), sporulation of the fungus occurs on the developed fungal filaments - conidiophores with chains of conidia. On the newly appeared spot of oidium, more and more new conidiophores grow, on which chains of fresh spores are laced.

Reproduction of the fungus during the entire growing season occurs with the help of conidia. Conidia can already appear at a temperature of 8 °, at 29-30 ° - their formation stops. High humidity contributes to the mass formation of spores; the optimal relative humidity for their occurrence is 60-80%.

The development of conidial sporulation of the oidium largely depends on meteorological conditions. With a favorable combination of temperature and air humidity, fungal filaments are able to form more and more conidiophores within 12 days. According to the observations of L. N. Makarov-Kozhukhov, in the Crimea, in some cases, the continuous formation of conidia occurred for more than 1 1/2 months.

With an increase in temperature to 30 °, as well as a rapid decrease in the relative humidity of the air to 40% and below, one can notice the mass death of conidia and conidiophores. The viability of mealy plaque is reduced to 5 days. The phenomenon of mass extinction of conidiophores and conidia is especially often observed in summer, during dry winds, sometimes blowing for several days in a row. During these winds, the humidity of the air decreases very much, and the temperature rises. The spread and development of oidium is delayed for some time. During calm, warm weather with high relative humidity, the oidium develops especially strongly. That is why oidium brings significant harm in areas adjacent to the Black and Caspian Seas, where the proximity of the sea causes high air humidity.

For the same reason, the disease strongly affects clusters, leaves and shoots located inside the bush (cup-shaped, arched, pedestal, spreading, Astrakhan, etc. formations), as well as under the shade fruit trees. So, according to D.N. Teterevnikova-Babayan (1951), in Armenia, 52.6% of clusters were affected on the trellis system, of which 7.1% were affected to a strong extent, while on the pedestal system, respectively, 66.0 and 37, 1%, i.e., more than a third of all bunches actually rotted. This phenomenon is usually observed in areas with hot summers. On the contrary, in places with cooler summers, where the air humidity is high and the temperature is lower, the oidium develops more strongly on trellises and vines winding near the walls of houses. According to the observations of V. E. Tairov in Odessa, oidium affected grapes on trellises more severely.

Significant and frequent rains stop the development of the disease for some time, since the streams of water wash away a large number of conidia to the ground.

In autumn, small spherical dark brown bodies appear on the gray bloom of oidium, visible to the naked eye. They are held by spirally twisted thin appendages. These are winter fruiting bodies of the fungus - perithecia, having from 75 to 105μ in diameter. Perithecia contain 3-4 egg-oval bags. Each bag contains 6-7 (rarely 4-5) oval spores.

Perithecia develop in autumn, mainly on affected berries and leaves. The role of perithecia in the spring renewal of oidium long time remained unclear, since the artificial infection of the vine by them did not cause the manifestation of the disease. D. N. Teterevnikova-Babayan (1951) found that the perithecia found on succumbing leaves in the soil, as well as on vines covered with earth for the winter, decompose under the influence of soil microorganisms. They can winter only in protected places, somewhere under a canopy, in greenhouses.

According to Western European and Soviet researchers, the oidium overwinters as a thick-walled brown mycelium on infected shoots, mainly at the nodes in the folds of the bark, and also in the buds, between the scales. In the spring, the hyphae begin to grow and form the summer conidial sporonosphere. From these foci, spores spread to the rest of the vineyards. The first appearance of oidium is usually observed on the same foci.

In areas of intensive development of oidium (Central Asia, the southern coast of Crimea, the Armenian SSR), the disease may appear as early as May, before flowering. In other places, it is usually found only after flowering (at the end of June or even in July).

Among European and local grape varieties, there are no absolutely resistant vines to oidium. However, their degree of damage is not the same. In each area there are more and less affected varieties. In the Crimea, Aligote, Semillon, Kokur, Silvaner, Chassela, Tagobi, and others are the most resistant; in Armenia - Aligote, Black Muscat, Early Aushon, Semillon; in Azerbaijan, the Matrassa variety stands out with significant resistance.

Control measures. Selection of healthy planting material. Pruning of annual vines affected by oidium. Plowing and digging the soil in the vineyard. Timely implementation of all agrotechnical work that reduces the thickening of the bushes and contributes to their better ventilation (removal of weeds, tying, breaking, pinching, chasing). Reconstruction of vineyards: transfer to trellis formation of bushes with spreading, arched, pedestal, bowl-shaped, Moldavian, Astrakhan and other forms.

The most common chemical way to deal with oidium is dusting vineyards with ground sulfur or sulfur. In the presence of sulfur, fungal filaments, conidiophores and conidia gradually shrivel and collapse. Thus, opylivapio with sulfur is not only a preventive, but also a therapeutic measure.

The efficiency of dusting with sulfur largely depends on the air temperature. According to the observations of AD Lipetskaya (1948), at a temperature of 6°C, the complete death of spores was noted only 11 days after pollination. At 16-18°, sulfur already gives much better results, but still, within these temperature limits, one day is not enough for the complete death of oidium. Only at temperatures above 19° did all the conidiophores perish in a day. With an increase in temperature, the efficiency of dusting with sulfur increases. At a temperature of 29-31°C, all conidiophores died after 7-4 hours and even after 2 hours.

Relative air humidity below 90% has little effect on the efficiency of sulfur dusting. At high air humidity (above 90%), the effect of sulfur increases significantly. The best results are obtained by dusting with dew-gray. When testing pollination with sulfur by dew in the Anapa region of the Krasnodar Territory, a 4-fold decrease in the damage to bushes by oidium was obtained compared to vines pollinated after the dew dries.

The good effect of sulfur during dusting by dew is apparently due to its better fixation on the bushes, i.e., greater retention, as well as its faster decomposition during dew evaporation. According to some foreign researchers, sulfur in the presence of water and atmospheric oxygen turns into volatile pentathionic acid, which is credited with a toxic effect on the oidium pathogen. There were no burns during dusting due to dew, since sulfur does not dissolve in water, and insolation in the morning, when dew is usually observed, is still weak. AI Petrov, TS Panfilova (1952) believe that in Uzbekistan pollination is best done in the evening or early in the morning when the plants are wet. It is advisable to test dusting with sulfur by dew in other areas of viticulture.

Depending on the season, the strength of the growth of bushes and formations during pollination consume from 15 to 30 kg of sulfur per 1 ha. With a lack of sulfur, as well as for better spraying, a mixture of it with fluffy lime is used in a ratio of 1:1 and 2:1.

At temperatures below 20 °, when the effectiveness of sulfur is insufficient, the bushes are sprayed with a 0.5 ° solution of lime-weed decoction or 1-1.5% suspension of colloidal sulfur. When the terms of the fight against mildio and oidium coincide, the vineyards are sprayed with 1% Bordeaux liquid mixed with colloidal sulfur (1 kg of colloidal sulfur is taken per 100 liters of 1% Bordeaux liquid).

Of the other substances that do not contain sulfur, solutions of soda ash and potassium permanganate are used to combat oidium. Soda ash is used in the form of 0.5-0.6% solutions. Molasses, sugar or soap are added to it. Soda has medicinal properties- clusters are gradually cleared of fungal plaque if spraying is repeated every 10 days. For the treatment of especially valuable collection varieties affected by oidium, a 0.05% solution of potassium permanganate is used (50 g of potassium permanganate per 100 l of water), which, being a strong oxidizing agent, acts very quickly on the mycelium and conidia of the fungus, which causes diseased clusters and leaves to be cleared from flying. However, its effect is very short-lived, and after a few days (4-5) the berries can again become covered with bloom. As a result, after spraying with potassium permanganate, they are immediately pollinated with sulfur.

In Bulgaria, according to E. Raikov (1954), in summer time spraying with potassium permanganate and dusting with sulfur is recommended. For 100 liters of water, take 125 g of potassium permanganate and 600 g of quicklime. P. N. Antonov (1954) also advises the use of potassium permanganate, effective in any weather. With early spring spraying, stronger solutions are prepared: 350 g of potassium permanganate and 3 kg of slaked lime are taken per 100 liters of water, while weaker solutions are used for summer spraying: for 100 liters of water - 150 g of potassium permanganate and 3 kg of slaked lime.

Of these chemicals, powdered sulfur is most often used, since dusting is a more productive work than spraying, and, moreover, during dusting, the powder penetrates better into the bush and settles on the clusters. With trellis formations that allow uniform covering of the brushes with a solution, it is better to use spraying.

Timing chemical control with oidium and the number of working off in the summer depends on the time of occurrence of the disease in the area and the intensity of the development of oidium. In areas of annual strong and early manifestation of oidium (Central Asia, Crimea, etc.), the first pollination of vineyards is carried out before flowering, shortly after bud break. In other areas, the first pollination is usually started when signs of oidium appear. Sulfur dusting is especially important during or at the end of the flowering of grapes, since newly set berries are especially susceptible to disease, and therefore it is necessary to protect them from damage in a timely manner. Subsequent pollination is carried out in 10-20 days, depending on the meteorological conditions of the year and the development of oidium. After the rains washed away the sulfur, dusting is repeated.

In areas of intensive development of oidium, 3-4 pollinations are carried out over the summer, and sometimes more. In places of weak distribution of oidium, they are limited to 1-2 dustings with sulfur, or they fight only on foci. Three weeks before harvesting, dusting with sulfur is stopped.

To prevent the spread of oidium, it is first necessary to pollinate the foci, which in each farm must be identified by annual observations. Additional treatments with poisons are carried out here during the summer. In fertilized areas, especially with nitrogenous fertilizers, due to the powerful growth of the green parts of the bushes, which creates favorable conditions for the development of oidium, additional dusting is used if necessary. In irrigated vineyards, they are pollinated after watering or the day before watering.

V. M. Shablykina tested at the state farm "Azerbaijan" a bacterial method of combating oidium, first used by P. N. Davydov on gooseberries against powdery mildew. To do this, one part (by weight) of old cow dung (dung for fuel with a small admixture of the earth under it) is taken, mixed with large quantity rotten hay, and is poured with three parts of water. After 3 days, the infusion is diluted with three parts of water and the affected bushes are sprayed in the morning or evening hours so that the drops do not dry out longer and the sun's rays do not kill the bacteria. The mycolytic bacteria developed in the infusion destroy the mycelium of the oidium pathogen, and the affected plants are cured. The effectiveness of the infusion was higher than that of dusting with sulfur.

To combat the overwintering mycelium of the fungus in areas of annual strong development of oidium (Central Asia, etc.), the vines are sprayed in a leafless state in the fall, before shelter for the winter, or in the spring after pruning, before bud break, 5 ° ISO, which simultaneously acts against diseases cercosporosis and anthracnose, as well as mites. In areas of weaker development of oidium, the fight against overwintering mycelium is inflated only on foci. D. N. Teterevnikova-Babayan (1951) and D. D. Verderevsky (1954) recommend spraying foci with a 1.5-2 ° ISO solution. D. D. Verderevsky also considers it possible to replace lime-sulfur decoction with 8% carbolineum emulsion.

Anthracnose

Anthracnose, or grape pox, is a fairly common disease in the southern regions. Within the USSR, anthracnose is especially harmful in Central Asia, Kazakhstan and the Transcaucasus, as well as in the Sochi region. It not only causes damage to the crop, but also greatly weakens the bushes.

In other viticultural areas, anthracnose occurs only in some years. It is noted in Ukraine, in Moldova, in Dagestan, in the Rostov, Astrakhan regions, in the Stavropol and Krasnodar regions. However, here anthracnose does not have a massive and annual distribution.

Anthracnose affects all green organs of the grape bush: shoots, leaves, inflorescences, berries.

First, a small brownish spot appears on the shoot, which gradually expands, then the spot is pressed in and, due to the elongation of the shoot, takes an oblong or oval shape. The spots often merge and form deep longitudinal ulcers with irregular edges. In the center of the spots, the tissue of the bark and wood is destroyed to the core, while only the vascular bundles remain intact, which can be seen in the depths of the wound in the form of individual fibers. Along the edges of the wounds, callus influxes are formed, as a result of which the edges of the ulcers are raised. The initial brown color of spots and ulcers turns black. With a strong defeat of the shoots, they acquire a black, charred appearance. The affected shoots are deformed, bent, become brittle, as a result of which they easily break in the wind. Finally, they can completely dry out.

The leaves on the affected shoots are small and take on a yellow color, they often dry out due to a disturbed supply of nutrients.

With a direct disease of the leaves with anthracnose, the same ulcers form on the petioles and veins, as on the shoots, which causes the curvature of the leaves. When the leaf plate is damaged, brown, of various sizes and shapes, often angular spots appear, surrounded by a dark brown or reddish border. Affected spots, collapsing, fall out, which is a characteristic feature for this disease.

When anthracnose appears during flowering, characteristic spots are formed on the inflorescences (comb, pedicels and flowers), surrounded by a black border. Affected flowers fall off in mass.

In a later period, on the berries, before ripening, rounded, gray or brownish, depressed spots appear, surrounded by a black or dark purple border. Spots are single or merging, and in the latter case they form one large ulcer of irregular shape. Under the influence of anthracnose, the berries become lopsided. Sometimes, in pouring berries, the skin on the depressed place gives a crack through which the seeds protrude, as happens with the defeat of oidium.

The causative agent of anthracnose is the fungus Gloeosporium ampelophagum (Pass.) Sacc.

According to Mangin's research, the mycelium of the fungus, absorbing the nutrient juices of the plant, at the same time decomposes the intercellular substance that binds the cells together, as a result of which the tissues are separated, prolapsed and ulcers are formed.

In some places, under the cuticle, dense plexuses of mycelium are formed in the form of flat pads, on which short vertical, cylindrical conidiophores develop in a dense layer, at the top of which they lace up. one colorless oblong unicellular spore 6-3 d long and 2.5-3.5μ wide. Spores contain two drops of oil.

Due to the growth of conidiophores, the cuticle is torn and the conidia protrude. They are surrounded by mucus, which sticks them together in dry weather. In water, the mucus swells and the conidia separate from each other. Due to this biological feature of the fungus, the spread of spores is mainly carried out during precipitation. Accumulations of spores on the surface of the affected tissues are very weakly visible to the naked eye and only sometimes give a grayish coating.

By the end of summer, the conidial beds are filled with a dense plexus of mycelium, forming sclerotia. In spring, the sclerotia turn back into conidial pads, producing conidia. Sclerocial formations can persist in old ulcers for several years, giving rise to a fresh layer of spore-bearing beds in the spring.

The causative agent of anthracnose has the ability to produce various forms of sporulation, depending on the conditions. environment. So, in addition to conidial beds, it can form pycnidia on berries and shoots, in the depths of wounds. Their appearance is usually associated with the presence of high humidity and a certain temperature. Pycnidia appear as black dots on the gray background of the spot.

At the top of the pycnidia there is a rounded opening through which spores that have a pink color come out.

In addition to sclerotia, conidial and pycnidial stages, the causative agent of anthracnose can form oidia and cysts. Oidia originate from the dissection of hyphae into individual oval or lemon-shaped cells, which multiply like yeast by budding. Cysts appear by dismembering the mycelium into individual cells or a group of cells that are dressed in a thick dark brown shell. Inside them, oval-shaped spores arise. Cysts are formed when unfavorable conditions for the development of the fungus occur: depletion of the nutrient medium, excessive heat, drought. They are highly durable. Of all the stages of the fungus described above, conidial pads are the most common.

In the second half of summer, pycnidia appear on the berries.

The fungus overwinters in the form of mycelium inside the tissues of the affected shoots, as well as in the stage of sclerotia and pycnidia. The mushroom picker is able to live in shoot tissues for up to 3-5 years.

According to the studies of T. S. Panfilova (1950), individual spores of the fungus cannot remain viable for a long time in anthracnose ulcers. She found that scattered conidia lose their viability after 10-15 days.

The spread of conidia and infection with them can occur only with drop-liquid moisture. Germination of spores, according to the observations of T. S. Panfilova, takes place at temperatures of 11-40 °. The most intensive spore germination occurs at temperatures of 23-32°C. At a temperature of 20--25 °, conidia germinate in 2-4 hours into elongated sprouts that can pierce the cuticle and thus penetrate into the tissues of the vine.

T. S. Panfilova, studying the biology of the causative agent of anthracnose in the conditions of Central Asia, found that temperature affects the intensity of infection and the duration of the incubation period of the disease, and even the nature of the development of anthracnose spots. The smallest number of affected shoots and smaller anthracnose spots are observed at temperatures above 30°C. The smallest incubation period occurs at temperatures of 24-30 ° (3-4 days), subject to frequent rains. The incubation period also depends on the age of the leaves, shoots and variety. The younger the tissue, the shorter the incubation period. During the season, the fungus can produce up to 30 generations.

T. S. Panfilova found that shoots are susceptible to infection during the first two months of their existence, leaves - within one month.

In the presence of warm and very rainy weather in spring, spotted anthracnose develops very early, with bud break, since the bushes are very unstable at this time, due to the presence of young shoots. It develops especially strongly during flowering.

In Central Asia, anthracnose mainly has a significant development at the beginning of the growing season. In the second half of summer, the spread of the disease stops, due to the cessation of precipitation by this time. In autumn, it often rains here at rather high temperatures, which causes the transition of the dormant stages of the fungus to mass sporulation. However, the bushes at this time have considerable stability, and therefore the germinated spores die without forming a mycelium. After such an autumn, according to the observations of T. S. Panfilova, anthracnose affects vines less on next year, since during the autumn the fungus will use up a significant part of the reserve nutrients.

Anthracnose not only directly reduces the yield, but also has big influence on the course of physiological processes. The development of anthracnose from spring causes a slowdown in shoot growth. The presence of open ulcers on them not only causes the fragility of the shoots, but also disrupts the flow of nutrients and water from the roots to the leaves and the outflow of plastic substances from the leaves to the roots, increases the evaporation of water through the ulcers, and reduces the frost resistance and drought resistance of the bushes. Anthracnose affects the vine not only in the year of the disease, but also in the subsequent period.

Vineyards located in low damp places, along the banks of large ditches and rivers, in areas with dense planting, poorly blown by the wind, are especially affected by anthracnose. Vineyards with arched and spreading formations are more affected by the disease than those cultivated on a trellis.

Control measures. When harvesting cuttings, in order to prevent the introduction of anthracnose to newly planted vineyards, vines affected by this disease should be strictly rejected. All vine cuttings should be burned before bud break, as they may retain overwintering stages of the fungus.

Deep plowing of vineyards and a complex of agrotechnical works that improve the ventilation of the bushes, as well as the drainage of damp soils through drainage in low areas, reduce the disease of the bushes with anthracnose. Excessive watering should also be avoided. In areas where anthracnose is widespread, it is necessary to lay vineyards on a trellis.

Of the chemical control measures, good results are obtained by spraying in the spring, before bud break, with a solution of iron sulfate. Most often, 6 or 10% solutions of iron sulfate are used (6 or 10 kg of iron sulfate per 100 liters of water) or a mixture of a solution of iron sulfate with sulfuric acid. To prepare the last solution, 10 kg of iron sulfate and 1 kg of sulfuric acid or 6 kg of iron sulfate and 250 cm3 of acid are taken per 100 liters of water. Spraying can be carried out in the autumn-winter period, after pruning.

After spraying the vines with iron vitriol, they either turn black or acquire a dirty brown color. It is noted that spraying the bushes with iron vitriol delays the opening of the eyes for 10-15 days. This is important for some regions as an event that protects plants from spring frosts.

Instead of ferrous sulphate, bushes can be sprayed in spring, before bud break, or in autumn, before sheltering bushes, with 8% carbolineum emulsion or 5 ° ISO solution.

After bud break, they are pollinated with pure sulfur or a mixture of sulfur with 20-60% fluff lime. Viala recommends that the first pollination with sulfur should be carried out in the spring, when the shoots reach 8-10 cm. , at the last dusting 2 parts sulfur and 3 parts lime.

Used in the fight against mildew and other diseases, 1% Bordeaux mixture can also be used against anthracnose.

Chemical treatments of vineyards during the growing season begin against anthracnose with blooming leaves, the second working out is carried out before flowering and the third - after flowering. If necessary, subsequent working off is repeated every 10 days, depending on the development of the disease.

Planting resistant varieties in areas where anthracnose develops annually can greatly reduce the damage caused by the disease. In the republics of Central Asia, European varieties are the most resistant: Saperavi, Cabernet, Riesling; from local varieties: Nimrang, Charas, Buaki, Parkent. Strongly affected: Khusayne, Chilyagi, Ichkimor, Yakdona, Khoja, Ak-Kishmish, Kara-Kishmish, Katta-Kurgan, Turkmeni.

white rot

White rot on individual bushes is ubiquitous, with the exception of northern viticulture areas.

In some areas of the Krasnodar Territory and the Georgian SSR (Kakheti), white rot develops annually. Usually, the mass defeat of vineyards by this disease is observed only after hailstorms, when up to 50% or more of the crop can die from it.

White rot affects clusters, leaves and shoots. Most often, the disease occurs on the hands. Berries infected with white rot first turn brown, as if boiled, then shrivel and dry. Browning quickly covers a comb, a group or all the berries on a bunch, which usually dries out the entire brush or a significant part of it. Such clusters remain hanging on the bushes for some time. On the surface of the shriveled berries and on the crest, small, spherical, densely located tubercles of an off-white color appear. In some cases, the bumps darken and become completely black. These tuberculate formations represent the fruiting of the fungus - the causative agent of the disease.

On green shoots infected with white rot, the tissue also turns brown, tubercles appear, as on berries. In the future, the bark splits and lags behind, as if it swells, then the shoot dries out. Occasionally, the disease also occurs on lignified shoots. In 1939, in the Temryuk region of the Krasnodar Territory, wilting and drying out from white rot were observed in seedlings of champagne varieties planted from hotbeds in shkolku. Infection occurred, apparently, through wounds during pruning.

P. I. Nagorny (1930) found white rot on chibouks of grapes in Kakheti on that part of them that was in the soil of the nursery.

Affected leaves have a dull dirty green color and soon dry out due to the rapid spread of the mycelium of the pathogen in the leaf tissues. Affected leaves after drying continue to hang on the bushes.

The causative agent of white rot is the microscopic fungus Coniothyrium diplodiella (Speg.) Sacc. developing inside the tissues of the green organs of the bush: leaves, clusters, shoots.

Infection occurs mainly through wounds caused by hail and gnawing insects. However, under favorable conditions for spore germination, infection can also occur through intact tissues. In the latter case, the fruiting of the fungus on the berries appears 3-4 days later than on those infected through wounds. According to the observations of E. M. Storozhenko in the Krasnodar Territory, white rot can develop on fruits affected by mildew and having sunburn.

Tuberous formations that appear on tissues affected by white rot represent the fruiting of the fungus - pycnidia, spherical containers, immersed in their lower part into the plant tissue. Inside the pycnidia, spores are formed, which exit through a small opening located at the top of the pycnidia.

At the bottom of the pycnidia, short cylindrical conidiophores are densely located, on top of which there are initially colorless, and then light olive, unicellular spores. The shape of the spores is oval, ovoid or spindle-shaped.

Once in water or on a fresh wound, the spores germinate and penetrate their germ tubes into the tissue of the vine. Spores germinate easily in water at a temperature of 18-20°C. The optimum temperature for germination (according to Istvanfi) is 25-30°. Under favorable conditions (temperature 22-27 °), the first germ tubes appear after 11 hours.

Fungal threads quickly spread among the cells of the plant, causing the tissue to turn brown, and soon pycnidia appear on the affected area. Browning of berries begins already on the second day, while pycnidia are formed on the 5-7th day after infection.

For the development of the disease, especially favorable conditions are high temperature and high humidity. As a result, white rot usually does not appear on berries until July. At this time, there is the highest air temperature and in the event of hail and heavy rain, a massive development of the disease is observed. In this case, for the most part, the lower clusters, located closer to the moist soil, are infected. This is due, on the one hand, to their possible infection from the soil during hail and rain with the help of hailstones and splashes of water bouncing off the ground and, on the other hand, to the longer non-drying of wounds from hail on clusters close to moist soil, which ensures germination. mushroom spore. According to the studies of A.D. Lipetskaya, infection through hailstones can be carried out even a few days after the hail falls, provided that the wounds are wetted with water.

White rot can develop on both green and ripening berries. The fungus overwinters with the help of dormant pycnidia or in the form of dense plexuses of fungal filaments - sclerotia. On fallen berries, spores in pycnidia can survive for several years.

In the Georgian SSR, the varieties most resistant to white rot are Aligote, Semillon, Mtsvane, and Cabernet. In the Kuban are less affected: Cabernet, Portugizer and Shasla.

Control measures. Selection of healthy planting material not infected with white rot. Removal from the vineyard and burning of all clusters and shoots affected by white rot. Timely implementation of all agrotechnical work, which ensures less thickening of the bushes and faster drying of the soil surface.

The spores of the pathogen are highly resistant to the most common chemical control agents: sulfur and copper preparations. So, Bordeaux liquid, even at a 2% concentration, does not kill spores. Only germ tubes die in this solution. Therefore, to combat white rot, 4% Bordeaux mixture is used.

Of the new drugs that can successfully replace 4% Bordeaux berry in the fight against white rot, E. M. Storozheiko recommends using a 4% suspension of 15% TMTD preparation or 1% suspension of 50% TMTD preparation in years with a strong development of the disease. With a weak development of the disease, vineyards can be sprayed with a 1% suspension of 15% TMTD or a 1% suspension of dinitrorhodanbenzene with copper oxychloride.

According to E. M. Storozhenko, in areas where white rot develops annually, the first spraying should be carried out after the berries have reached the size of a pea or when a disease is detected. If necessary, spraying is repeated after 10 days. In areas where white rot appears mainly after hail damage, the first spraying of brushes is done as soon as possible after hail to kill the spore germ tubes. Spraying brushes should be thorough and plentiful.

black rot

Black rot is noted in Transcaucasia (Georgia, Azerbaijan), in the North Caucasus (Stavropol and Krasnodar Territories), in Moldova, in Ukraine (especially in Crimea) and in the vineyards of some Central Asian republics (Tajik and Turkmen SSR). Every year the disease develops in Kakheti.

In Russia, black rot first appeared at the end of the last century (in the Caucasus and Crimea) and spread to a fairly large extent. However, in recent years, black rot, although it occurs in vineyards, causes harm only after hail damage.

Black rot most often affects leaves and berries, less often shoots. Numerous, round or slightly elongated, sharply limited spots 2-3 mm in diameter are formed on leaves (mainly on young ones), and 2-4 cm in size at the ends of the lobes; the last spots always occur by merging smaller spots. They take on the color of the dried leaf, the same on both sides of the plate. At this stage of development, black rot spots look like burns. Some time after the appearance of spots, black small tubercles are formed on both sides of the leaf (4-5 on small spots). On large spots, more of them appear and they are arranged here in irregular concentric groups. Petioles and leaf veins are also affected by black rot.

On berries, black rot develops before the grapes ripen. At first, a small spot appears, which quickly increases and takes on a bluish-red tint, darker in the center and lighter at the edges. The spot expands so quickly over the surface of the berry and in depth that after 1-2 days the whole of it is covered by the disease. The flesh becomes flabby, spongy and less juicy. Soon, the berry begins to fade, wrinkle. After 3-4 days, and sometimes 2 days after the onset of the disease, the berry dries completely and takes on a thick black tint with a bluish tint. The skin and pulp become thin, wrinkled and stick to the seeds. By this time, small black tubercles appear on the surface of the berry, less than a pinhead in size. They are so densely located on the surface of the berry that the skin seems shagreen. All these changes occur within 3-4 days. The berries do not immediately fall off, but remain on the brush until autumn, and only later are separated along with part of the ridge, or with the stalk.

The disease appears on individual berries and then spreads to others. As a result, on one bunch you can see berries in different stages of the disease. When maturation begins, the disease develops more slowly.

On the shoots, black-gray, elongated along the length of the vine spots are formed, slightly swollen or cracked, dotted with black tubercles, which are most often found in the region of the nodes, although they can also be located on the internodes. Usually the spot rarely covers the shoot from all sides. If such a phenomenon occurs, then the shoot above the affected part dries up and falls off.

Black rot is caused by marsupial fungi Guignardia Bidwellii (Ell.) Vial, et Rav. and Guignardia baccae (Cav.) Zacz. and from the imperfect fungi Phoma lenticularis Cav. Guignardia Bidwellii infects leaves, green shoots, combs and berries, Guignardia baccae develops only on shoots and berries, Phoma lenticularis settles only on berries.

The first appearance of the disease in spring or early summer, caused by Guignardia Bidwellii, occurs on the leaves, where pycnidia soon form. This conidial stage is called Phoma uvicola Berk, et Curt. Guignardia baccae appears first on young shoots and produces here pycnidia known as Phoma reniformis Viala et Ravaz.

On berries, both types of fungus form pycnidia containing two kinds of spores: in some conidia, small ones are microconidia, in others, larger conidia are macroconidia. First, pycnidia with microconidia appear, which are observed in the first half of summer, but at the end of summer and autumn they are almost never found. Instead, they form pycnidia with macroconidia. The biological role of microconidia is still unclear.

Macroconidia have considerable resistance to adverse conditions (drought, low temperatures). They are glued together with a slimy mass that swells in the presence of moisture and shrinks in a dry environment. In a dry state, macroconidia can retain their vital activity for a long time (more than a year). For their germination, drop-liquid moisture is needed, which dissolves the mucus that sticks the spores together. The optimum temperature for the germination of conidia is 20-25 °. Table 2 shows the characteristics of the pycnidial stage of the pathogen.

During drought or when the temperature drops (up to 8-10°C), spore formation in pycnidia ceases, and their cavities are filled with multifaceted, colorless cells. So-called resting pycnidia are formed. Of these, pycnidia with micro- and macroconidia most often develop, which in the spring cause the primary infection of the vine.

Less often, perithecia are formed in these pycnidia, and in Guignardia Bidwellii, bags in perithecia develop only in spring, while in Guignardia baccae they are also found in winter among Phoma-type fruitings. Perithecia have an outlet through which moisture enters them and causes the bags to swell, after which spores are released and either leaves or shoots are infected. Table 3 shows the characteristics of the perithecia of the black rot pathogen.

The entire development cycle of both types of fungus can be characterized by the following points:

As can be seen, both types of fungus have the same stages of fruiting and the time of their formation. The fungus Fnoma lenticularis forms clustered, lenticular-shaped pycnidia on berries. The biology of this black rot pathogen has not been studied.

Black rot is very dangerous for berries, as it can destroy most of the crop. For leaves and shoots, this disease cannot be considered very harmful, it does not bring visible damage to these organs, and the bushes develop normally. Favorable conditions for the development of the disease are created in rainy weather, accompanied by high temperature and high humidity. The incubation period on the leaves lasts 12-20 days, and on the berries it is shorter: 6-10 days pass from the moment of infection to the formation of spores.

Control measures. Compliance with all conditions of agricultural technology, providing good air circulation in the vineyards. Removal and burning of clusters dried up from black rot, pruning of diseased shoots. From chemical control measures, spraying with 1% Bordeaux liquid is used (the first time the disease appears on the leaves). Since Bordeaux liquid is not a therapeutic, but only a preventive remedy, the first spraying should be completed before the appearance of pycnidia on leaves or shoots. In France, before flowering, 3-4 sprays with Bordeaux liquid are carried out to prevent the disease from moving to the brushes.

Diplodia

Diplodiasis is a rare disease. For the first time in Russia, this disease was discovered in Azerbaijan in 1897 by A. A. Yachevsky and N. N. Speshnev, who named the pathogen Diplodia uvicola Jacz. et Speschn. According to A. A. Yachevsky, Diplodia uvicola causes damage to berries, similar to black rot.

P. N. Kostyuk (1948) noted this disease on the island of Dzharylgach in the Black Sea and near Odessa. M. A. Kublitskaya discovered diplodia in 1954 in the Uzbek SSR, in the Tashkent region.

The fungus Diplodia uvicola only affects berries, on which depressed, rounded brown or brown spots are formed, sometimes painted blackish. blue color, dotted with spherical pycnidia, first covered by the epidermis, and then protruding to the surface of the substrate. Inside the pycnidia are ovoid-ellipsoidal spores, olive-colored, two-celled, 9-11X4.5μ.

In Uzbekistan, the disease develops mainly on varieties with dense clusters: Black Pinot, Mourvedre, Bayan Shirey, Frankenthal, Tashbuaki.

A. M. Kublitskaya believes that the appearance of the fungus in 1954 was due to high humidity and a relatively short period of high air temperature. Diplodia was encountered in Uzbekistan in both trellis-forming vineyards (well-heated and ventilated) and cultivated planted bushes (shaded and under conditions of high dampness). The biology of the causative agent of this disease has not yet been studied.

Control measures. Removal and burning of affected clusters. Spraying vineyards with 1% Bordeaux mixture at the first signs of the disease.

Gray rot

Gray rot is common in all viticultural areas. It is caused by the fungus Botrytis cinerea Pers.

Gray rot most often develops on berries during their ripening period. The berries turn brown, shrivel, the skin is often torn, and the berry is covered with a powdery coating of gray. Rotting quickly covers the entire bunch, especially in varieties with dense brushes.

In years with wet, rainy autumn, it causes massive rotting of berries and worsens their taste. Wine obtained from such berries acquires an unpleasant musty smell. In addition, in red varieties, the destruction of dyes occurs. White wines made from berries affected by gray mold are very unstable and have turned the wife brown.

If gray rot develops on ripe berries and at this time the weather is warm and dry, then the affected berries become raisined, and their sugar concentration increases. This form of decay is called noble rot. In some places, such as Bordeaux (France) and the Rhine (Germany), noble rot contributes to wines high quality. In some years, noble rot also develops in the vineyards of the Ukrainian SSR.

Gray rot can also develop on inflorescences, causing them to completely dry out.

When cultivating grapes in very humid and poorly ventilated greenhouses, gray mold can also settle on leaves and shoots that quickly rot (especially the tops) and become covered with a gray bloom.

According to the observations of P. N. Kostyuk, A. G. Mishurenko and P. M. Shterenberg (1954), in Ukraine there is a defeat of gray mold cuttings and seedlings during their winter storage in soil or sand. The disease usually begins from a transverse cut of the vine from the eye or tendril. When cutting such cuttings, brown blurry stripes are visible in the area of ​​wood and cambium. When placed in damp conditions, sections of vines with necrotic spots become covered with a gray coating of the fungus. One of the reasons for the occurrence of spotty necrosis of grape cuttings and seedlings, the authors consider the penetration of the fungus Botrytis cinerea into the tissues of the vine.

The causative agent of gray rot can settle both on green healthy tissues of the vine, and on its dead parts. The powdery gray coating that forms on the nibbling berries is a sporulation of the fungus, consisting of tree-branched coyoidiophores, on which unicellular, colorless or grayish, ovoid or ellipsoidal conidia sit, arranged in groups, like bunches of grapes.

During the slightest movement of air, spores crumble and are transferred to new places. With sufficient moisture, they germinate. Their germ tubes penetrate the tissues of the vine and develop there into a mycelium. A few days later, a gray coating forms on the affected areas - conidiophores with conidia.

A particularly rapid and massive spread of the disease occurs when the skin of the berries is damaged by hail, as well as by a leafworm, and when it is damaged by oidium.

In some years, the strong development of gray mold on bunches is associated with the meteorological conditions of the year.

So, if, after a long dry period, rainy weather sets in by the time of ripening, this causes the formation of numerous small cracks on the berries, through which mass infection occurs, which causes large crop losses. The same strong defeat of brushes with gray rot occurs in irrigated vineyards in Native Asia with improper regulation of irrigation. So, with insufficient watering, the skin of the berries becomes thick and tough. If, after this, abundant watering is given, then, under the influence of an increased influx of water, the skin of the berries bursts, which causes the massive development of gray rot.

In some years, gray rot develops so strongly that when grapes are loaded into a press, a cloud of dust, consisting of spores, rises.

In autumn, black, spherical or oblong tubercles 2-4 mm in diameter appear on fallen berries and leaves, on dead shoots. Under a microscope, you can see that they are a dense plexus of fungal filaments, the outer layer of which is brown or black in color, and the inner one is white. Similar formations (sclerotia) serve for overwintering of the fungus.

In spring, when the air temperature reaches 12°C, the sclerotia germinate. At the same time, the same branched conidiophores with conidia are most often formed on the sclerotia, which develop in a lot on the affected parts of the vine. In more rare cases, brown fleshy cups 0.2-0.5 mm in diameter grow on sclerotia, sitting on oblong legs of the same color. These cups are the fruiting bodies of the fungus. In their notched bottom there are cylindrical bags, inside of which there are 8 oval spores, 9-11X5-6μ in size. As soon as these spores emerge from the bags, they immediately germinate. In this marsupial stage, the fungus is called Sclerotinia Fuckeliana (Do Bary) Fuck.

Control measures. Removal of decayed clusters and pruned vines from the vineyard in autumn. Timely plowing of the soil and green operations (debris, pinching, chasing), reducing the thickening of the bushes, as well as tying the vines. Proper regulation of irrigation in irrigated vineyards.

The fight against gray rot by the chemical method, especially when it develops during the ripening of grapes, is very difficult, since during this period many drugs cannot be used because of the possibility of them getting into the wine. In addition, gray mold spores are very resistant to various chemicals. They can remain viable even in a 3% solution of Bordeaux mixture. Thereby chemical method control of gray mold is currently poorly developed.

Positive results are obtained by spraying the clusters before ripening with a 1% solution of green soap (1 kg of soap per 100 liters of water). Processing wine varieties grapes are carried out but later than 2 weeks before harvesting, and table varieties can be sprayed later.

Since damage to the skin of berries contributes to the development of gray rot, therefore, special attention should be paid to the fight against grape leafworm and oidium. Excessive one-way nitrogen fertilization should also be avoided. Measures to protect cuttings and seedlings from damage by gray rot during storage are given in the description of necrosis of the vessels of wood of grape seedlings.

cercosporosis

Cercosporosis is found in the vineyards of Central Asia, Transcaucasia, North Caucasus, Moldova and Ukraine. It is especially widespread in the Central Asian republics and in some regions of Armenia, where it can cause a significant crop shortage.

The causative agents of this disease are fungi from the genus Cercospora. In the Soviet Union, 4 species cause harm: Cercospora Roesleri (Catt.) Sacc, Cercospofa vitis (Lev.) Sacc, Cercospora sessilis Sorok. and Cercospora vitiphylla Barb. However, the Cercospora species listed are not found in all areas.

As can be seen from Table 4, 3 species are most widespread: C. Roesleri, C. vitis and C. sessilis. C. vitiphylla is found only in the vineyards of Central Asia and Armenia.

On the lower surface of the affected leaves, a dark olive, velvety coating forms, which is why this disease is sometimes called "green mold". Plaque is easily erased with a finger. On the upper side of the sheet, the fabric remains green at first. Then it turns yellow or rounded or angular spots of a brownish-ocher color with a yellow or dark border form on it. Sometimes the border is missing. Affected leaves fall off easily when shaken.

C. Roesleri is sometimes found on green shoots in the form of a dense bristly, velvety coating, brownish-olive in color.

C. vitis and C. roesleri can also infect berries and stems. With the defeat of the berries and stalks of C. vitis, a slightly noticeable olive bristly coating is formed. C. Roesleri first causes a thick, velvety brownish-olive coating on berries and stalks, which is easily erased. Then, before the grapes ripen, the affected berries gradually harden and acquire a blue color at the base, sometimes covering the lower half of the berry (adjacent to the stalk). At the point of attachment, the berry shrinks, the peduncle dries up and, at the slightest shaking, the berries fall off,

Cercosporosis mainly affects the leaves, while the berries rarely get sick. The green plaque covering the leaves, stalks, berries and shoots is the sporulation of the fungus, protruding through the stomata in the form of tufts. Under the microscope, bunches of conidiophores protrude from the stomata with cylindrical or club-shaped spores, painted in olive or smoky color and having from one to five, and sometimes more partitions. An accurate determination of the type of causative agent of cercosporosis on the leaves is possible only after microscopic examination.

In C. vitis, black pycnidia containing colorless, rod-shaped spores were found to form on dead leaves, as well as on hardened blue areas of the affected berries. Later, in place of the pycnidia, perithecia appear with club-shaped or cylindrical bags. The bags contain colorless, straight or bent, club-shaped, two-celled spores. This marsupial stage is called Mycosphaerella personata.

N. G. Zaprometov (1925) distinguishes in Central Asia the spring cercospore, which develops in spring, and the autumn cercospore, which develops in late summer and autumn. The appearance of cercosporosis in spring in Central Asia is caused by the fungus Cercospora vitis, and in summer and autumn by the fungi Cercospora Roesleri and Cercospora vitiphylla.

In the Armenian SSR and in a number of regions of the Stavropol Territory, the cercospore develops most intensively only at the end of summer, when high air temperatures set in,

The initial appearance of the disease begins on the lower leaves located closer to the soil surface, which is apparently due to the heat radiated by the soil both during the day and at night, and higher air humidity. The development of the disease, mainly on the lower leaves, is facilitated by shading, which is so necessary for the growth of the fungus, as well as increased air humidity in the surface layer.

With a strong infection of the cercosiora, the leaves of the middle and, in rare cases, the upper tiers will also be covered. Most often, old leaves get sick and weaker - middle-aged and young.

Cercosporosis is found mostly in old neglected vineyards that are too densely planted, and also weakened due to poor care or damage by pests and other diseases.

In the Uzbek and Tajik SSRs, the disease develops more strongly in arched and spreading vineyards. On healthy, with good care In vineyards, almost no cercosporosis is observed. Mass shedding of leaves leads to crop shortages and poor maturation of vine wood, which reduces their frost resistance.

In Central Asia, local varieties are more affected by cercosporosis than European varieties. Severely affected varieties include: Nimrang, Buaki, Katta-Kurgan, Taifi, Khusayne, Vassarga, Nurbuaki and sultanas; to the weakly affected - Ichkimor, Parkent. According to the observations of G.S. Gambaryan, in the Armenian SSR the most susceptible variety to cercosporosis is Ararati.

Control measures. The main control measures are agricultural practices that eliminate favorable conditions for the development of the disease. To this end, it is necessary to avoid dense planting of grapes, form bushes on a trellis, observe the irrigation regime, avoiding prolonged stagnation of water in low places. It is imperative to carry out plowing between rows and digging in rows, which is important not only as an agricultural technique, but also as an event that ensures the movement of fallen affected leaves into deep soil layers.

Timely and carefully conduct pest and disease control, chipping, garter, chasing, weed control. In order to avoid infection of bunches with a pedestal system for cultivating grapes, use supports under the bunches, which will improve the aeration of the lower part of the bushes.

Since cercospore sporulation develops from the underside of the leaves, when spraying, it is necessary to direct a jet of liquid not only to the upper, but also to their lower surface.

In autumn, before closing the vines, or in spring, before bud break, spray 5° ISO.

Septoria

Septoria (melanosis) is found in Transcaucasia, Ukraine and Moldova. It affects mainly the leaves of American vines and their hybrids. In European varieties, the disease is very rare. It was not observed on berries and shoots.

The first (external) signs of the disease are small dot-like light brown spots that form on both sides of the leaf. Increasing, they acquire an angular shape, being limited by the last branches of the nerves, which apparently prevent the further spread of the mycelium. The size of the spots ranges from 0.5 to 2-3 mm. The spots are usually numerous. In the future, their color becomes dark brown and even black. On the upper side of the leaf, their color is darker than on the underside.

Usually yellowed leaves of the lower tier are affected; in the upper part of the bush, the disease is relatively rare. With a strong lesion, the leaves turn yellow and dry out, their edges are bent inside the plate. The leaves remain hanging on the vine. Their plate is easily torn off, and the petiole is held rather firmly.

The causative agents of melanosis in Ukraine and Transcaucasia are three species of Septoria: Septoria ampelina Berk, et Curt., Septoria melanosa (Vialet Ravaz) Elenkin, Septoria viticola P. Bran. S. melanosa is the most common.

The mycelium has very thin, colorless hyphae with septa that are significantly distant from one another and a small granular protoplasm, as a result of which it is difficult to observe it inside the tissues. The mycelium is located in the intercellular spaces and almost never penetrates into the cells. Under the influence of the mycelium, the cells with which it comes into contact lose their elasticity, darken and die, as a result of which characteristic spots appear.

When examining the spots in a magnifying glass, one can notice on both sides of the leaf the smallest numerous black convex dots, which are pycnidia of the fungus, covered by the epidermis or slightly protruding. Pycnidia have a fairly wide excretory opening through which long, very narrow spores emerge, with several septa. Spores germinate in water at a temperature of 18 to 30°C.

The disease usually develops in the second half of summer, does not cause significant lesions. However, with an annual appearance, melanosis can weaken the bushes and prevent the vine from maturing normally. The causative agent of the disease overwinters on the affected leaves and again forms spores in pycnidia in the spring.

Control measures. To reduce the harmfulness of the disease, mother liquors of American vines should be planted on a trellis or tie the vines to stakes. Of the chemical control measures, spraying with 2% Bordeaux liquid is used, starting from May - June (2-3 times a month) and ending in September.

root rot

Root rot has been noted in Transcaucasia, the North Caucasus, Moldova and Ukraine. It develops mainly on dense, excessively moist soils, with poorly permeable subsoil, causing water stagnation.

Affected bushes have weak growth, small, yellowing leaves, short internodes. After 2-3 or more years, they die. Yields in the first one or two years of the disease are often increased, and then sharply reduced.

Infected areas resemble phyllokey lesions. In the center of the outbreak, the bushes are the most oppressed or already dead; towards the periphery of the infected area, their appearance is somewhat better. Sick bushes have browned or completely dead root lobes, from where the disease passes to thicker roots. In the future, browning extends to the underground trunk of the bush.

Accumulations of white threads and strands form on the surface of the roots, often covering the affected roots with a continuous mass. The root tissue becomes spongy, the bark at the root collar is easily separated. When the root neck is wounded, especially in spring or autumn, a thick black liquid protrudes from the trunk. Bushes are easily pulled out of the ground.

Root rot is caused by the fungus Rosellinia necatrix (P. Hartig) Berl.

Unlike other fungal diseases of the grapevine, Rosellinia necatrix can affect not only grapes, but also other plants.

Rosellinia necatrix belongs to semi-saprophytic fungi, as it usually settles on dead parts of plants and passes to living ones only when they are weakened for any reason. In this case, the hyphae of the fungus penetrate the living roots and feed on the living plant.

The mycelium covers the roots not only from the surface, but also develops between the bark and their wood, where it forms fan-shaped spreading white films or branched cords (rhizomorphs) of brown or black color, having a fibrous surface.

The soil adjacent to the affected bush is also permeated with strands of white mycelium, as a result of which infection of new bushes can occur not only from the contact of the roots of healthy and diseased bushes, but also through the soil.

Natrass (Natrass) believes that the fungus is able to infect only thin roots, the death of which leads to the death of the bush.

The mycelium covering the roots can look like strands, ribbons, ragged and cotton-like clusters, fan-shaped films that have a white, gray and greenish-gray color. On the soil, the mycelium is in the form of white thin, loose threads.

On microscopic examination, the mycelium of Rosellinia necatrix appears in two forms: in the form of thin, slightly curved and slightly branched filaments, almost the same thickness along its entire length, and in the form of thicker filaments that form pear-shaped or cone-shaped swellings near the cell walls (P.I. Upland).

2-3 years after the death of the bush, mycelial plexuses disappear and small rounded black sclerotia appear on the roots. Most often, sclerotia are formed on the trunk near the root collar, under the bark. They are located in longitudinal parallel rows, often go out through the ruptures of the bark. Their diameter is from 2 to 5 mm. Subsequently, closely fused, vertically spaced bundles of branched conidiophores (so-called coremia), painted in dark color, appear on the sclerotia. Numerous colorless ovoid conidia are cut off at the ends of the branches. In water, these conidia germinate and after 3-4 days (at a temperature of 25-30 °) give a sprout that develops into a felt mycelium. Sclerotia can turn into pycnidia, which are most often located along the medullary rays of the root. They break through the bark and come out. Pycnidia contain bicellular brown spores.

Finally, on the destroyed roots, perithecia appear, which look like black balls up to 1.5 mm in size. Often they are found together with bundles of conidiophores (koremias). Inside the perithecia are cylindrical bags, rounded at the top. The bags are located in perithecia among special threads called paraphyses. Each bag contains 8 dark brown spores, spindle-shaped, slightly depressed on one side, and convex on the other.

Root rot most often develops on clay and marl soils, as water easily stagnates in them. On sandy, calcareous, granite, and generally on easily permeable soils, the development of root rot is less rapid. It often appears in vineyards planted on the ground, cleared from under thickets of oak, spruce, pine, and fruit trees.

Old vines are more easily affected by rot than young ones, although very young plants can also dry out quickly due to root rot. The most favorable temperature for the development of mycelium is 22-25°; at a temperature of 8 to 12 °, the development of the fungus slows down.

Control measures. Vineyards should be avoided in heavy, damp soils. Vineyard areas where the soil remains wet for long periods of time should be drained and treated appropriately to aerate the soil. These measures can not only prevent the onset of the disease, but even stop the disease that has already begun.

In the event of the death of the bushes, the foci are destroyed, uprooting the obviously affected and suspicious bushes and burning them on the spot in the pit. After that, the hearth is fenced with a ditch and the soil is disinfected with carbon disulfide. After a few weeks, the soil is plowed up and left for a year, after which grapes can be planted.

If, after burning the bushes, the soil is not seeded with carbon disulfide, then the hearth is left unplanted with a vine for 3 years. During this period, only cereal crops can be sown on it. Affected bushes, and those that are still vegetative, are rejuvenated using the katavlak method.

Affected plants differ from healthy ones by the yellow color of the leaves (chlorosis), especially between the veins. In addition to yellowing of the leaves, on some bushes there is a short knot, crushing of the leaf blade and the development of many thin stepchildren, which is why the plant has a bushy appearance. This form of manifestation of chlorosis is called cottis.

The first signs of the disease are found in May in the form of a light yellow color along the edges of the leaf. Yellowing then spreads to the entire leaf blade, with the exception of areas adjacent to the main veins, which remain green for a long time. The growth of the bush is noticeably weakened.

The spread of fungi of the genus Fusarium occurs, apparently, with irrigation waters, and where vineyards border on cotton fields, vegetable gardens, melons, their soils are heavily infected with Fusarium. As you know, Central Asia is an ancient cotton-growing region, until recently cotton was a permanent crop in the same fields, as a result of which fungi from the genera Fusarium and Verticillium accumulated in the soil, which are the causative agents of wilting, or "wilt", of cotton and many vegetable crops.

Cold, long spring, abundant with precipitation; contributes to the strong development of Fusarium, since pathogenic forms of fungi most easily infect plants at a temperature of 4-7 ° and 75% humidity. With the onset of hot and dry days (in July - August), the Fusarium fungus loses its activity.

The following varieties are most severely affected by Fusarium: Muscat, Saperavi, Black Pinot, Semillon, Aleatico, Morastel, Cabernet, Rkatsiteli, Riesling, Bayan-shirey, Oporto.

Control measures. Compliance with all the rules of agrotechnical care for vineyards. Sowing on irrigated vineyards (through row-spacing) legume-cereal grass mixtures, using them for 3 years. By the end of the third year of life, they are plowed up, and grasses are sown on unsown aisles. M. A. Kublitskaya recommends using the following grass mixtures for this purpose:

1) alfalfa + multi-cut ryegrass + cocksfoot combined at the rate of 10 kg of alfalfa and 6 kg of cereal grasses per 1 ha;

2) alfalfa + ryegrass, at a seeding rate of 12 kg of alfalfa and 8 kg of ryegrass per 1 ha.

It is recommended to sow herbs only in irrigated vineyards or in sufficiently moist places. Legume-cereal grasses help to improve the nitrogen and water-air regime of the soil, as well as the accumulation of mycolytic bacteria (destroying fungi) and actinomycetes in it, which cleanse the soil from pathogenic forms of the Fusarium fungus. It is recommended to periodically spray the vineyards when the first signs of chlorination with 1% Bordeaux mixture appear.

Esca

The disease of the vine, called eska, was noted in the vineyards of Moldova, Ukraine, Transcaucasia and the North Caucasus. Eska is a corruption of the Greek word "isca", which means tinder fungus. Tinder fungi are fungi that can destroy wood.

In France, this disease was described in the last century by Henry Marais under the name of folletage and apoplexy, and it was explained by physiological causes. Later, namely in 1901-1909, Rawaz described a disease called apoplexy caused by the fungus Stereum hirsutum (Willci.) Fr. He attributed the phenomenon of folletage to physiological causes: the action of sunlight, which causes excessive evaporation of moisture from the leaves, a sharp change in temperature, the influence of drying winds, etc. Vialya (1922) retained the old name for this disease (esca), which is now generally accepted. Vial considered the causative agent of the disease the new kind, which he named Stereum necator Viala.

Stereum hirsutum can also affect oak, beech, chestnut, poplar, olives and other tree species.

The disease is characterized by the following symptoms: outwardly healthy bushes begin to wither, the leaves lose their turgor and luster, become dirty green or gray in color, the berries become brick red and shrivel, the entire bush dies within a short time. Most often, such a rapid death of plants is observed in the hot summer months (in July - August). Another form of the disease is chronic and occurs more frequently in vineyards. Affected bushes differ sharply from healthy ones in their bright red (in red varieties) or yellow (in white varieties) leaves between the main veins. In the future, the leaf tissue between the main veins dries out and only small strips of it remain green. These leaves fall off. Clusters wither and dry up, as well as shoots. Often the bushes have shortened internodes and form many stepchildren.

On a longitudinal section of the trunk of the affected bushes, severely destroyed rotten wood is visible. Damage to tissues by the fungus occurs gradually, in zones; growth rings darken, which is why they stand out sharply from the normally colored (yellowish) part of healthy tissue. Diseased wood is always delimited from healthy tissue with a dark brown border. The most severely affected, to a rotten state, is the central part of the bole. The trunk and sleeves of diseased bushes, drying out, form more or less deep cracks.

When the last annual ring is damaged by the fungus, the connection of the roots with the aerial part stops, and rapid wilting and death of plants occurs. That is why outwardly healthy bushes that have wood affected by esca can die within a few days when hot, dry weather sets in.

The fungus is found only in the wood of the aerial part of the bush, it does not occur in the roots, which some researchers explain by the fact that the fungus does not have time to reach the root system, due to the death of the bush. The roots of the affected bushes remain healthy, and if you cut off the dead bush at the root neck, then a healthy young growth appears.

Rawaz believes that the bushes die 10-12 years after infection with the fungus. Vialya, on the other hand, observed the death of bushes 4-5 years after infection.

Stereum hirsutum (Willd.) Fr. refers to the basidiomycetes, forming hard half-caps, attached sideways to the trunk, sitting like tiles one above the other. Their upper surface is densely hairy, with concentric stripes, light ocher or grayish in color. The lower surface is colored yellowish and is a fruit-bearing tissue on which the basidia are located one next to the other. Basidiospores - cylindrical, with rounded ends, colorless.

Fruit bodies are very rare. According to Vial, they come across from a thousand bushes once. According to the observations of a number of researchers, the spread of the fungus occurs as follows: in the mass of the substrate, thin, resembling tissue paper, black sclerotial formations are observed, which are a complex of densely lying cells with very granular protoplasm; when the vine is destroyed, these films are converted by disintegration into constituent elements - cells - a dusty mass, which gets out through the cracks in the trunk and is carried by the wind. The formations in question are distinguished by increased resistance to various adverse conditions and, when stored in a humid environment, do not lose viability for 11-12 years.

In addition, in the trunks that died from apoplexy, sclerocial cords are observed, which are built from parallel, tightly soldered black threads; the ends of these threads, as it were, split, unwind, and conidia are separated on them - endospores, unicellular formations (P. I. Nagorny). When the endospore germinates, the membrane bursts and the contents of the cell come out, forming a thick sprout, which then extends into a thin thread of mycelium. In the central, most destroyed part of the bole, densely penetrated by the mycelium of the fungus, cavities are formed in which a large number of conidia (endoconidia) develop.

The penetration of the fungus occurs with mechanical damage, as well as through wounds inflicted during pruning, and the sap that acts during this is a favorable environment for the development of mycelium.

According to Vial's research, the fungus never infects healthy tissue. It secretes diastasis, which oxidizes tannin and acts on cells, as a result of which they are killed. After that, the mycelium moves to dead tissues, destroys them and turns dense wood into a spongy, rotten tissue.

According to D. D. Verderevsky (1946), the initial substrate on which the fungus settles when the bush is injured is the dead tissue of the bole and the dead tissue of the core exposed during pruning. Bushes affected by esca are found mainly in old vineyards of 15-20 years of age. According to the research of D "Asti, young bushes contain little tannin, as a result of which they represent an unfavorable environment for the development of the fungus. Only from the age of 12-13 years does the amount of tannin in the vines begin to noticeably increase and reaches its maximum by 25-30 years.

According to the studies of D. D. Verderevsky in Moldova, wood-destroying fungi isolated from diseased boles, including Stereum hirsutum, easily take root on the core of the shank, causing further darkening and necrosis of the living wood adjacent to the core. In this regard, he suggests that the primary penetration of esca pathogens into vineyards can occur along with planting material. The technique of stratification of seedlings in non-disinfected sawdust containing a large number of wood-destroying fungi, including Stereum hirsutum, which is widespread in forests and on dead wood, leads to infection of seedlings.

The core of a mature vine is made up of dead cells; this provides a favorable substrate for saprophytic nutrition of the fungus.

Bushes affected by esca are usually found in the form of single specimens or small groups. However, according to the observations of D. D. Verderevsky, in 1945 in Moldova the wood of European grafted vines was affected by esca in almost 80% of the bushes. This disease is also widespread in hybrids - direct producers.

Along with Stereum hirsutum, other types of wood-destroying fungi were isolated from the affected plants.

D. D. Verderevsky believes that such a large distribution of esca in the vineyards of Moldova is due not only to the activity of wood-destroying fungi, but also to some conditions that weaken the bushes, which ensures the penetration of fungi into the plant tissue. Drought can be attributed to such depressing factors. A significant appearance of eska in Moldova coincides with dry years. D. D. Verderevsky believes that phylloxera is also one of the factors depressing bushes in Moldova.

Control measures. To prevent infection of seedlings during stratification, D. D. Verderevsky recommends disinfecting sawdust by steaming or pre-disinfecting them with formalin. 40% formalin is diluted with water (1 liter of formalin per 300 liters of water) and then the sawdust is moistened with this solution (150-200 liters of solution per 1 ton of sawdust). The wetted sawdust is covered with a tarpaulin or bags soaked in a formalin solution. After 24 hours of languor, the sawdust is scattered in the shade with a thin layer for ventilation. Disinfection of sawdust with formalin is carried out no later than two weeks before their use. Apply them after that only when the smell of formalin has completely evaporated. Sawdust is also disinfected by scalding with boiling water.

To increase the stability of the vine, it is necessary to carry out the entire complex of agrotechnical measures in a timely and thorough manner. The use of mineral and organic fertilizers sharply reduces the severity of this disease.

When bushes shriveled from esca are found, their above-ground part is cut down and immediately burned to prevent the dispersion of spores through cracks that form in the wood of the dead bushes. The shoots formed on the sawn bushes are used to restore plants.

Vialya suggests treating plants affected by the chronic form of esca by spraying after pruning (before bud break) with a solution of sodium arsenic acid mixed with soda (20 kg of poison and 1 kg of soda per 100 liters of water). At the same time, all wounds are well moistened with a solution. It is recommended to scrape out rotten wood affected by the fungus with a spoon and then lubricate the wounds with the above-mentioned solution of arsenic sodium.

Eye mold

In the sheltered zone of viticulture, the development of mold fungi is often observed on the sheltered vine, including on the eyes.

According to the studies of P. N. Kostyuk and V. M. Rachkov (1949), three types of fungi are most often found on sheltered vines in Ukraine: Mucor racemosus Fres., Cladosporium herbarum (Pers.) Link, and Macrosporium vitis Sorok. Settling first on dead tissues, they then penetrate into living cells.

Mucor racemosus and Cladosporium herbarum mainly destroy superficial tissues, while Macrosporium vitis develops mainly inside living eyes, causing their death.

Fungi develop less frequently on sheltered plants: Fusarium Zavianum Sacc. and Coniothecium macrosporum Sorok. They are found both on the vines and on the eyes. In autumn and winter, these fungi live as saprophytes, and by spring they switch to living tissues.

Increased soil moisture contributes to the intensive reproduction of the aforementioned fungi and the infection of new plants with them. Significant mold growth of buds and vines is especially observed at temperatures above 2°C (in a moist cover layer of soil).

Control measures. To protect the eyes and vines from mold, the Ukrainian Research Institute of Viticulture and Winemaking named after V. E. Tairov recommends spraying the vines before covering the bushes with a 5% solution of iron sulfate. D. D. Verderevsky believes that spraying-washing the vines in the fall with 8% carbolineum emulsion with the addition of 0.5-1% granosan (8 kg of carbolineum and 0.5-1 kg of granosan per 92 liters of water) gives even better results.

bacterial cancer

Bacterial cancer is widespread in all viticultural regions of the USSR. Most often, it develops on lignified above-ground parts of the bush: stem, sleeves and vines, on which rounded or oblong callus influxes form, with an uneven, tortuous surface. The size of the nodules range from small nodules with a diameter of 0.5 cm to large formations with a diameter of 10 cm or more. When located along the stem, they can be up to 30 cm.

Cancerous tumors usually appear in the spring, at the site of cracks and wounds. At first, a tuberculous callus with an uneven surface develops, which quickly increases, fills the cavity of a crack or wound and goes beyond it. Outgrowths-tumors are formed that disfigure the bushes.

At the beginning of its development, cancerous tumors are light yellow or pale pink in color, juicy. They soon turn brown and hard from the surface. During the autumn and winter, cancerous tumors die off and partially fall off, and in the spring new growths appear under them or next to them.

Cancer nodules are sometimes found on the underground part of seedlings, which is most often the case with vines cut from cancer-affected bushes. Small cancerous nodules can also form on green shoots, which is sometimes observed after hailstorms.

The causative agent of cancer is the bacterium Bacterium tumefaciens Smith et Townsond, which, in addition to the vine, can infect up to 40 species of various higher plants, such as apple, pear, apricot, peach, almond, blackberry, currant and other trees and shrubs, as well as some herbaceous plants .

Bacterium tumefaciens, when grown on artificial nutrient media, is a short movable rod 0.4-0.8X1.0-3.0μ in size. and with 2-3 flagella at one end. This bacterium is found in almost all soils. It can overwinter in the soil and on its surface at a minimum temperature of -32°.

In the closed viticulture zone, the penetration of bacteria is carried out not only through frost cracks, but also through wounds formed when branches are bent before sheltering bushes, as well as through cuts made by tools when opening vines in spring. In the zone of grafted vineyards, cancerous tumors most often develop at the site of the "adhesion" of the scion and rootstock.

B. tumefaciens is an aerobic organism, thus. cannot develop without access to oxygen, as a result of which bacteria are concentrated only in the superficial cells of the tumor, they are not found in the depths of the nodular tissue.

The increased growth of cancerous tumors causes a large influx of plastic substances from the leaves to these places, as a result of which the plant is depleted, the growth of shoots and the yield are reduced. The annual formation of new and new tumors leads to the gradual death of the bush, as a result of which bald spots form in the vineyards.

Control measures. To prevent the introduction of the disease to newly planted vineyards, cuttings for planting should only be harvested from healthy bushes.

If seedlings affected by cancer are found during the growing season, they must be immediately removed and burned. The remaining healthy seedlings (when dug out of the school in autumn) are disinfected by immersion for 1-2 minutes in a 1% suspension of granosan, followed by rinsing with clean water.

When pruning vineyards, it is necessary to cut and burn the affected parts of the bush, as well as remove the bushes that died from cancer. After pruning plants with cancer, tools should be disinfected with a 5% formalin solution.

In case of a severe defeat and a weakened state, diseased bushes are rejuvenated by cutting them "on a black head" or laying them with katavlak. When caring for bushes, you should protect them from mechanical damage, and also protect them well from frost.

Of the therapeutic measures, P. N. Kostyuk recommends applying a coating of the affected areas of the bush with 5% copper naphthenate, prepared from copper sulfate and green soap and dissolved in autol. 2-3 days before treatment, holes about 15 cm deep are made around the affected bushes in order to expose the root collar. Cancer nodules are brushed off with a thin wire brush and the cleaned places are lubricated with copper naphthenate. After 5-6 days after treatment, the wells are closed. Coating is carried out in late autumn or in early spring.

At the Suvorovsky state farm in the Stavropol Territory, 20% copper naphthenate dissolved in kerosene is successfully used against cancer without preliminary purification of the tumors, which greatly speeds up the work. D. D. Verderevsky recommends coating the wood cleared of nodules with an undiluted garden carbolineum concentrate.

Bacteriosis of berries

Bacteriosis of grape berries was first discovered in 1927 in Anapa, Krasnodar Territory and described by A. S. Merzhanian and M. V. Kovaleva (1930). Later, this disease was noted in other areas of the Krasnodar Territory, as well as in the Ukrainian SSR.

Bacteriosis of berries was first mistaken for a burn from high temperature and dry winds. In appearance, this disease is similar to the cup de pus disease described by Vial and Ravaz for France.

A disease appears on the berries when they reach the size of a pea or more. First, under the skin, mostly between the stalk and the umbilical cord, a small light yellow spot appears. At this point, a deepening soon forms, rapidly increasing. The color of the spot becomes brown or brownish-violet. The skin in the place of deepening dries up. Sometimes the disease stops at this stage, and then only one side of the berry is affected. More often, the disease progresses, the berry dries up completely and falls off. From the moment a barely noticeable deepening appears to the complete drying of the berry, 5-7 days pass. The disease usually occurs on individual berries and only rarely covers the entire brush.

In the anatomical study of spots with a recess, it was found that between the skin and the vascular fibrous bundle there are more flattened cells due to drying. The vascular fibrous bundles are largely destroyed and filled with a thick brownish substance. The tissue of the berry under the vascular-fibrous bundle has breaks and forms voids, which leads to subsidence of the skin and the appearance of depressions, formed as if from finger pressure.

A. S. Merzhanian and M. V. Kovaleva isolated and described the causative agent of this disease - a bacterium, which they called Bacillus vitis Merjanian et Kovaleva. However, G.K. Burgwitz renamed it Bacillus viticola Burgv., due to the existence since 1913 of the name Bacillus vitis for the causative agent of grape shoot deformation, studied abroad by Montemartini.

Bacteria are rods - single, in pairs or chains with rounded ends 0.83-1.25X2.5-5.0μ in size, forming spores. Their development can occur at temperatures from 7 to 43 °, the optimum temperature is 21-22 °.

Infection of the berry occurs before ripening, while the flesh is still firm. But as soon as the berry begins to ripen and soften, infection no longer occurs. Most often, berries are affected by bacteriosis from the sunny side. It is noticed that the disease is detected when daytime temperatures reach 28-30 °. Spores are very resistant to high temperatures and prolonged drying. With artificial infection, the appearance of the first signs of the disease was noticeable after 5-8 hours.

The bacterium penetrates into berries mainly by wounds and injections, although berries with intact koyashtsy can become infected. In Anapa, bacteriosis is more developed in vineyards located on sandy soil, since during dry winds the grains of sand cause the smallest scratches through which bacteria penetrate into the berries. The bacterium overwinters on fallen berries in the soil.

Table varieties of grapes with dense pulp of berries (Chaush, Bikan, etc.) are most affected. Bacteriosis of berries not only affects the yield, but worsens appearance table grapes.

Control measures. To prevent infection, the berries should be protected from mechanical damage, as well as timely control of pests that violate the integrity of the skin of the berries. Chemical measures to combat this disease have not been developed. According to the observations of A. S. Merzhanian and M. V. Kovaleva, some results are given by solutions of polysulfides, as well as sulfur in powder.

Short knot

Short knot is a long-known disease that was found only on single bushes and was considered a functional disease.

AT Western Europe short knots are called kurt-nue (France), reisigkrankheit (Germany), arrichiamento (Italy).

In the Soviet Union, a significant occurrence of the disease was noted in 1934 in vineyards near Yalta in the Crimea. VL Ryzhkov (1935) expressed his opinion about the viral nature of short knots in the Crimea.

In the postwar years, the mass development of the disease was found in the vineyards of the Moldavian SSR. D. D. Verderevsky (1946), who studied this disease in detail in Moldavia, considers short knot a disease of infectious degeneration of grapes.

Affected bushes differ sharply in appearance from healthy ones. The leaf blade decreases and is strongly deformed: the veins approach each other, a strong dissection is noted, resembling a parsley leaf. Instead of the petiole notch typical of healthy bushes, an elongated, triangular base of the leaf is formed. The leaf becomes uneven, bumpy. Mottled chlorotic areas first appear on it, which, expanding, cover almost the entire plate. longest green color preserved along the veins. Chlorotic leaves begin to dry out at the edges, and then die off completely.

Affected bushes are characterized by shortened shoot internodes and a large number of stepchildren. Shoots from straight lines become zigzag-curved. Internodes can be so close that so-called double nodes are formed. Due to the strong growth of individual stepchildren, the shoots become forked.

According to the observations of D. D. Verderevsky and K. N. Lukina (1948), ... "with infectious degeneration, in contrast to the functional short node, the lower six to eight internodes outwardly always develop normally and form normal foliage. Only at the end of spring ( seventh to ninth internode), noticeable signs of the disease appear, progressively increasing throughout the season. Flowering of diseased plants is accompanied by anomalies (bud cracking), abundant falling of flowers occurs.

The berries of diseased bushes are small, often do not ripen, tasteless, with a low sugar content. The yield of bushes is reduced and the quality of the must is deteriorating. The root system is also oppressed. The development of young roots in spring is delayed compared to their growth in normal plants. Young roots die prematurely and many new, small, coral-like ones grow in their place.

The death of bushes with a rapid course of the disease can occur 3-5 years after its manifestation.

However, kurts can live for a longer period and even acquire an outwardly healthy appearance for some time, but then they still die.

In vineyards infected with phylloxera, the short-node occurs very often in the form of significant foci, while in the rest of the massifs, the disease is observed only on individual bushes.

Anatomical examination of the leaf reveals necrosis, there is no chlorophyll in the affected cells, and there is no differentiation into palisade and spongy parenchyma in the tissues. In the vessels of wood there are deposits of gum (resin). According to Ravaz, Branas and D. D. Verderevsky, hallmark infectious short knot is also the presence in the wood tissues of long cord-like cells that cross one or more vessels. These cells are called endocellular cordons.

However, according to the studies of L. A. Kanchaveli, E. M. Eristavi, Sh. I. Tsertsvadze and M. R. Targamadze, conducted on large numbers varieties in the Georgian SSR, endocellular cordons are very common in perfectly healthy vines.

In bushes affected by short knots, more intensive respiration and transpiration is observed, the starch content in the leaves decreases.

Most often, short-knotted is found on European grape varieties grafted on rootstock vines Rupestris du Lo and Riparia X Rupestris 3309. The most resistant rootstocks are Riparia X Berlandieri. To a large extent, hybrids are also affected - direct producers, especially Rein-d'or. Own-rooted European vines are not affected by short knots in Moldova. In the Crimea, the disease was noted on European grape varieties.

Whether the short knot in Moldova and in the Crimea is an identical disease remains not yet clear.

The Italian scientist Petri expressed the opinion in 1931 that the short knot is a viral disease (Vitis virus 2). He observed the transmission of the disease through the soil. The French phytopathologist Branas, sharing the opinion of Petri, suggests that one of the main distributors of the disease is phylloxera. The infectious nature of the disease is proved by the fact that it is transmitted to both scion and rootstock during vaccination. Short knots can also be transmitted to offspring during vegetative propagation of grapes.

Vineyards located on heavy clay soils with poor aeration are most severely affected by short knots. On the contrary, on sandy soils, unfavorable for the development of phylloxera, the short-node is very rare and only on single bushes. In the Moldavian SSR, relatively young vineyards, 10-15 years old, are most severely affected. The intensity of the development of the disease increases in wet and cold weather. In the hot months, the signs of the disease are obscured. The most detrimental manifestation of short knots - the fall of the brushes - usually occurs at low temperatures during flowering.

Control measures with a short knot is not yet sufficiently developed.

When harvesting planting material, it is necessary to strictly cull vines that have signs of short knots. Severely affected, unproductive bushes should be uprooted and burned.

In preliminary experiments in the vineyards of Moldova, the application of mineral fertilizers and irrigation reduced the intensity of the disease to some extent. The introduction of zinc sulfate into the soil (up to 300 g for each bush) also had a beneficial effect.

infectious chlorosis

Infectious chlorosis was first noted in 1946 in the Georgian SSR, where it occurs on single bushes, especially on the Gorula-Mtsvane variety. Infectious chlorosis is also called vein chlorosis, chlorosis of the Gorula type (due to its pronounced manifestation on the Gorula-Mtsvane variety).

L. A. Kanchaveli, E. M. Eristavi, Sh. I. Tsertsvadze, M. R. Targamadze (1954), who studied this new disease, describe the appearance of its manifestation in this way. Affected bushes chlorosis, and this type of disease differs from chlorosis, due to physiological causes.

With infectious chlorosis, irregularly shaped bright yellow, later slightly creamy spots appear on the leaves, which, merging, stretch along the veins, giving a reticulate color to the plate, the chlorotic color gradually diffusely spreads over the plate and the entire plate becomes bright yellow over time, then whitish-cream color. It is characteristic that during the growing season, signs of chlorosis, due to climatic factors and plant phenology, for the most part masked in summer (young growth remains green).

Highly chlorotic old lower leaves become whitish and the recovering green color gives the leaf a speckled appearance, giving the impression of being splattered with whitish paint.

With functional chlorosis, yellowing of the leaves begins primarily between the veins of the leaf and the green color along the veins remains on the plate for a long time.

Vein chlorosis found in the Georgian SSR is similar to the disease described by V. L. Ryzhkov in 1946 under the name of mosaic disease, which he found near Otuz on the eastern coast of Crimea and in the vicinity of Yalta.

Similar symptoms of the disease are described in 1937. in Czechoslovakia Stranak, who believes that mosaic disease is caused by the Virus vitis Stranak virus (synonyms: Vine mosaic virus, Mosaic viticola) and can be transmitted by sap, aphids and peach scale insects.

In addition to the Georgian SSR, infectious chlorosis also occurs in the Moldavian SSR.

An anatomical study of the affected leaves shows that the cells in the chlorotic areas do not contain chlorophyll, the affected leaves have smaller cells of both the palisade and spongy parenchyma.

It was found that in the manifestation of infectious chlorosis there is a certain periodicity both in individual years and in seasons, and mass distribution is closely linked to the phenology of the plant. Infectious chlorosis is confined mainly to the spring period, and the mass manifestation of the disease is observed in the flowering phase.

In some years, at the beginning of autumn, a new, but very weak manifestation of the disease on young growth in the form of diffuse chloroticity can occasionally be observed (L. A. Kanchaveli, E. M. Eristavi, Sh. I. Tsertsvadze, M. R. Targamadze).

Sometimes the disease manifests itself in early spring in the form of a mosaic, and then takes on the character of vein chlorosis. During hot, dry weather, the disease is masked.

In Moldova, the disease is observed on weakened bushes.

Infectious chlorosis can be transmitted to healthy vines by grafting, which has been confirmed by numerous experiments. Infection by sucking insects is also possible.

Gorula-Mtsvane, Riparia X Rupestris 3309 and 3306 varieties are most affected in Georgia, occasionally this disease occurs on Rkatsiteli and Aligote varieties. BerlandieriX Ripariya 420-A, 5-BB and Chassela X Berlandieri 41-B have comparative stability. In Moldavia, infectious chlorosis occurs in mother liquors of under-war vines and on grafted European and hybrid bushes. This disease was not found on own-rooted vines of European varieties.

Control measures. To prevent the spread of the disease, grafting material should not be taken from the foci of chlorosis. It is recommended to use resistant varieties Berlandieri X Riparia 420-A and 5-BB. Nurseries of mother vines should be placed in places where chlorosis is not observed. Sick bushes in mother liquors of rootstock vines should be uprooted and the soil under them should be fumigated with dichloroethane bottoms to kill soil-dwelling insects. In place of uprooted plants, layering from healthy bushes is removed.

Dodder

Foci of dodder in vineyards are often found in the Uzbek and Tajik SSRs, as well as in Azerbaijan. There are isolated outbreaks also in the vineyards of Dagestan and Ukraine.

Couscut seeds germinate in the spring, during the budding of grapes. The dodder sprouts that have appeared have very thin, filiform stalks of yellow-pink color, which stretch wriggling in different directions. Having reached any weed or green vine shoot, the dodder clings to them. If there are no plants nearby, then the couscutta dies as soon as the nutrients contained in the seed run out. The dodder is attached to the host plant with suckers that can extract nutrients from the plant. As soon as the dodder begins to feed on the host plant, its roots die off, it becomes juicy and powerful. Its stems are long, up to 1 m or more. They wrap around the bushes, gradually entangling more and more new plants. In summer, pale purple or light pink flowers are formed on dodder, sitting on short pedicels. The flowers are collected in compact bunch-shaped formations. The fruit is a box. Dodder has a high fertility, one plant forms tens of thousands of seeds that can remain viable in the soil for up to 12 years.

In addition to seeds, dodder is easily propagated using stem cuttings. Dodder is very depleting plants. Bushes affected by it have weak growth, small clusters and berries, or do not bear fruit at all. Affected plants accumulate less nutrients by winter, so they suffer more from adverse conditions. Annual shoots affected by Dodder usually die off the next year. Often the whole bush dies.

Usually dodder occurs in patches. Its permanent habitats are irrigation ditches, hedges and other places that are difficult to cultivate. Particularly favorable conditions for couscutta on the vine are created during the spreading culture of grapes.

Control measures. Dodder is a quarantine weed, and all farms must fight it without fail, according to the instructions of the plant quarantine inspection.

Of the agrotechnical measures to combat dodder, 2-3-fold loosening of the soil in the spring, during the period of seed germination, is used. Control in the spring is most effective while the dodder is in the seedling stage and has not attached itself to the host plant. Therefore, in vineyards where dodder sprouts have appeared, it is especially necessary to destroy other weeds, to which kuskuta can attach, with particular care. In infected vineyards, spreading crops should not be allowed and shoots should be cut and tied up in a timely manner.

The fight against dodder should be organized not only in vineyards, but also along roads, irrigation canals, in green hedges. For the timely detection of dodder foci, it is necessary to periodically examine the vineyards.

When the dodder moves to grape bushes, the fight against it is much more complicated. Couscut stalks are manually torn off from the affected bushes, which are put in boxes, bags and other containers. It is necessary to ensure that scraps of stems do not remain on the ground, as they can take root again.

In autumn, after shedding the leaves, the bushes are cleared of dodder. Fallen leaves, dry grass, boxes and dodder seeds are raked and burned on the spot. In addition, within the radius of seed fall, a layer of soil 3-5 cm thick is removed, it is buried in a hole deeper than the arable layer and covered with clean earth with a layer of 30-40 cm.

In areas where there are no valuable cultivated plants, dodder is destroyed by spraying with a 2% solution of sodium arsenite (2 kg of poison per 100 l of water) or 10% solution of ammonium nitrate (10 kg of the drug per 100 l of water) with a liquid flow rate of up to 2000 l per 1 ha.

To destroy seedlings, dodder in vineyards pollinate the soil with ground sulfur. According to the Uzbek Institute of Viticulture (1952), after opening the bushes in the spring, row spacing is loosened, and then dusted with ground sulfur. Dusting begins from the moment dodder seedlings appear, which coincides with the beginning of budding of grapes. Dusting is repeated after 5-7 days. The consumption rate of sulfur is 100-150 g per 1 m 2.

According to the Kirovobad experimental station of viticulture (1956), good results in the fight against dodder were obtained by spraying the soil under the bushes with pure dichloroethane residues. During the month, three spring working off were carried out. Liquid consumption 120-150 cm 3 per 1 m 2. Double spraying of the soil with a 3% emulsion of the preparation 47 VIZR also showed good results.

Chlorosis

Chlorosis is a very common disease observed in all areas of grapevine growth; it is due to physiological reasons.

A characteristic sign of chlorosis is yellowing of the leaf blade. In most cases, the entire leaf turns yellow and only green areas remain along the main veins. With a strong manifestation of chlorosis, the edges of the sheet dry up, and then the entire plate dries out. The shoots also turn yellow, and their tops often die off, the internodes become short. On such shoots, many thin stepchildren develop, bearing small leaves. The whole plant takes on a bushy appearance. In this form, the disease is known as cottis.

Few berries are tied on chlorinating bushes. They are small and yellow. The processes of assimilation, respiration and evaporation in diseased plants are slow, the shoots are poorly woody and therefore not very resistant to frost. The vines taken from chlorinated bushes showed a reduced yield of grafts and a later development of buds on them.

The mass manifestation of the disease in the form of kottis is usually rare; for the most part, chlorosis is observed only on the upper leaves, while the lower ones remain green. Plants often become ill with chlorosis soon after the shoots open, but with the onset better conditions during the growing season, chlorosis completely disappears and the bushes take on a normal green color.

Chlorination of both the grapevine and other plants will eventually disrupt the metabolism. The disease occurs especially frequently and annually on carbonate soils (for example, in Kakheti and Imereti of the Georgian SSR, in the Anapa and Gelendzhik regions of the Krasnodar Territory, in the Moldavian SSR, etc.).

The disease can be caused by various reasons, some of them give a stable chlorosis of the bushes from year to year, others cause a temporary manifestation of chlorosis, which is then replaced by greening of the foliage.

The most persistent disease is closely associated with an excess of easily soluble lime in the soil. It has been established that chlorosis is caused by a violation of the process of normal absorption of mineral nutrients by the roots, especially lime. Chemical analyzes have shown that chlorinated leaves always contain more calcium and often iron. Calcium and iron seem to accumulate in them in a sedentary form. In the roots of a diseased vine, the amount of iron is less.

Excessive soil dampness, drought, low air and soil temperatures, excess salts, lack of iron, damage to the roots by pests and diseases - all this can cause chlorosis. However, it has not yet been possible to find out what physiological reasons cause the yellowing of the leaves.

Particularly strong chlorosis is observed on American vines, of which Riparia Gluar, Riparia X Rupestris 3306 and 3309, Labruska, Estivalis and others are especially susceptible to the disease. B.

Of the European varieties, the most resistant are: Chasselas, Portugizer, Clairette, Aramon, Mourvedre, Muscats, Morastel, Pinot, Cabernet Sauvignon, Trolinger, etc. Riesling, Aligote, Cabernet Franc are less resistant.

Control measures. When chlorinating bushes from excess moisture or drought, soil drainage is used or, conversely, irrigation of vineyards. It is necessary to plant varieties resistant to chlorosis both with own-rooted and rootstock grapes.

Of the chemical control measures, the following are known. Introduction into the soil under the bushes of iron sulfate (200-400 g per 1 bush). To do this, in the fall or early spring, they dig a ditch around the bushes, scatter iron vitriol along the bottom, then water it with water and cover it with earth. Lubrication of the vines with a 15% solution of iron sulfate in the fall, after pruning. Spraying the leaves with a 0.5-1% solution of iron sulfate (3-4 times during the growing season).

The Anapa experimental station for viticulture and winemaking has developed a method of soil acidification, which gives good results in the fight against chlorosis on carbonate soils. Between the bushes, pits are dug 45 cm deep and 25 cm wide, then 4-5 liters of sulfuric acid solution are poured into them. A small amount of earth is mixed into the solution. At the end of the reaction, the pits are closed and the soil is compacted,

For acidification, technical sulfuric acid (specific gravity 1.83-1.84) is used, which is diluted 20 times with water (sulfuric acid must be added to water, and not vice versa). Sulfuric acid converts carbonic lime into sulfuric acid and converts insoluble iron salts into compounds digestible for the roots.

It can also be used in vineyards columns from non-carbonate soil. To do this, they dig the same holes near the bushes, as in the case of acidification, and 10-15 kg of soil that does not contain lime are poured into them, and they are covered with the excavated soil from above. In such columns, small roots of the bush develop in mass, extracting digestible nutrients.

According to the Academy of Sciences of the Georgian SSR, the sowing of alfalfa and other leguminous grasses in irrigated vineyards gives good results in the fight against lime chlorosis. Herbs contribute to the development of beneficial microflora in the soil, which improves the mineral nutrition of bushes.

Vascular necrosis

Vessel necrosis of the wood of grape seedlings is often found in areas of grafted grapes (Ukraine, Moldova, Transcaucasia).

Grafted grape seedlings are most severely affected, although a significant manifestation of this disease was also noted in the schools of native-rooted seedlings of European varieties. In grafted plants, browning of the vessels is especially strong on the tissues of the rootstock.

If you make a cross section of the wood of seedlings, then in the affected plants you can clearly see a ring of brown dots. On longitudinal sections, brown intermittent strokes are visible, often located along the entire length of the seedling. Plants are stunted and have a poorly developed root system, in connection with which the yield of benign planting material decreases. Such seedlings, planted in place, grow weakly, and if the cambium cells are damaged, they die before fruiting.

PI Nagorny (1930) also found the presence of the fungus Fusarium viticolum Thuem in Transcaucasia in grafted seedlings and cuttings taken from bushes at the end of the growing season. Fusarium artificial infection of green shoots and grafts during the development of their roots and leaves did not give positive results. However, when cuttings are stored in humid conditions, the Fusarium can move from diseased to healthy vines (when they come into contact).

PN Kostyuk (1949) also noted for Ukraine the possibility of Fusarium infection of planting material during storage. In later works, P. N. Kostyuk, A. G. Mishurenko, P. M. Shterenberg (1954-1955) describe the appearance of spotty necrosis on the cuttings due to their infection with the fungus Botrytis cinerea Pers. The development of gray rot occurs in the covering shaft or when the vines are stored in conditions of high humidity, when they are interbedded with earth or sand.

Recently, P. N. Kostyuk and P. M. Shterenberg (1956) established the possibility of transmitting the disease from infected wood to healthy wood through the soil, while they were isolated from the affected tissues different kinds fungi, the pathogenicity of which has not yet been experimentally proven.

A. I. Mordvintsev, who was engaged in 1933-1935. elucidation of the causes of vascular necrosis of seedlings in the Transcaucasus, believes that the death of cells begins in grafts at the site of injury; in the vessels, tills (cells that clog the vessels) are formed, which subsequently acquire a brown color. Under favorable conditions, microorganisms (fusarium, verticillium, etc.) penetrate wounds, leading a saprophytic and semi-saprophytic lifestyle there.

S. A. Melnik (1940), who worked together with A. I. Borggardt, notes that the Fusarium fungus can develop only in the tissues of defective chibouks (unripe, frozen, dried) or if normal stratification and storage conditions are not observed. In view of this, he believes that Fusarium is not the root cause of necrosis of grafted seedlings,

X. I. Kuporitskaya (1954), based on experiments in Moldova during 1947-1950, comes to the conclusion that necrosis of seedlings is due to physiological causes not related to the activity of microorganisms. According to her observations, the disease occurs mainly not during the storage of cuttings, but directly in shkolki. High soil temperatures in July - August, as well as insufficient soil aeration contribute to the development of necrosis. In her opinion, the necrosis of the vessels of the wood of grape seedlings is a consequence of the increased intensity of intracellular respiration in rooted chibouks and grafts during the hot months of the growing season. Inside these chibouks and grafts, apparently, not only carbohydrates, but also proteins are used for respiration. Protein breakdown products cause tissue intoxication. Fungi from the genus Fusarium penetrating into necrotic tissues increase the harmfulness of this disease.

Control measures. To protect grape planting material from damage by necrosis of wood vessels during storage, P. N. Kostyuk, A. G. Mishurenko and P. M. Shterenberg recommend the following measures. Harvest the vine for propagation in late autumn so that it is well ripened by the time of pruning. Cut rootstock vines up to 1 m long and, after removing the tendrils and stepchildren, tie them into bunches of 200 pieces. Dig up seedlings from the school before the onset of autumn bad weather. Before laying the vines, trenches should be disinfected by spraying the bottom and moaning with a 10% solution of ferrous sulfate. Bundles of vines and seedlings should also be disinfected with a 5% solution of ferrous sulfate, immersing them for 2-3 seconds, then drying and storing.

When stored in trenches, the bottom is first covered with disinfected vine cuttings (15-20 cm layer) and then cuttings or seedlings are placed. Bunches of chibouks are laid in several rows and covered with 20-30 cm of vine trimmings and a layer of earth of 10-12 cm on top. In order to avoid damage to the vines by necrosis, they are not sprinkled with sand or earth.

When laying seedlings in trenches, the bundles are folded horizontally and only the roots and bases of the bole are sprinkled with sand. From above they are covered with cuttings of the vine with a layer of 20-30 cm and earth. For the winter, the trenches are covered with a thicker layer of earth. To avoid water leakage, a drainage ditch is dug around the trench.

When stored in basements, they are cleaned of litter and the walls are whitewashed with lime and blue vitriol. The floor is first covered with wet sand with a layer of 5-6 cm. The sand must have such moisture that it does not crumble when compressed in the hand. In those farms where necrosis of the wood of seedlings was observed in the previous year, sand should not be reused. The roots and bases of the stems of the stacked seedlings are sprinkled with sand.

If the vine is kept in cellars, the bundles are stacked and the ends covered with wet sand. From above, the stack is covered with cuttings of the vine, and then with a layer of sand 10-15 cm. Wetting sand in a pile is not allowed, as water can flow into the vine. The temperature in storage facilities should be maintained within 0-5°. To avoid drying of seedlings, the relative humidity in the basement should not fall below 75-80%.

When planting vaccinations for 1 running. m schoolchildren take 10 liters of water, in which 1.8 g of boric acid is dissolved. First, 1/3 of the solution is poured onto the bottom of the groove, then the soil is moistened when the grafts fall asleep at 1/3 of their height, and finally, the remaining amount of the solution is poured after filling the groove at 2/3 of the height. Secondarily, boron is applied at the rate of 1 linear meter. m 0.6 g of boric acid per 10 liters of water; this solution is watered the soil near the grafts.

The most effective use of boron fertilizers on sandy and light loamy soils. At the same time, the whole complex of agrotechnical measures for the care of the school should be carried out.

Spotted necrosis

Spotted necrosis (dry arm) of the vine is a disease discovered in relatively recent times. It was first described by Mordvintsev in 1937.

Spotted tissue necrosis occurs mainly in the vineyards of the covering zone: in Ukraine, including in the steppe part of the Crimea, in the Rostov region, Krasnodar and Stavropol Territory, in Moldova, in Kazakhstan, Uzbekistan and the Dagestan ASSR.

This disease appears during the dormant period on perennial sleeves and less often on annual vines. First, a spotty browning of the soft bast and medullary rays is detected. In subsequent winters, the death of bast and wood increases, and often the dead part rings the entire branch. Due to impaired sap flow, the development of buds is delayed, which often completely die on annual vines. Shoots grow weak, often chlorinating, sometimes they wither already at the end of spring. The yield of such bushes drops sharply. In the future, the sleeves dry out along with the healthy replacement knots and arcs located on them.

According to long-term observations by E. I. Zakharova (1953), the most severe damage to bushes by spotted necrosis occurs in years with relatively warm winters, a significant amount of precipitation and. the presence of repeatedly changing freezing and thawing of the soil cover.

In the northern regions of viticulture (Tambov, Saratov, Kuibyshev and other regions), where winter is stable, without thaws, followed by frosts, spotted necrosis is absent. The appearance of dead spots of bast and wood can occur when the soil temperature in the covering shafts is already about -5 °. It is known that the uncovered aerial part of the bush is able to endure much lower temperatures. Damage to the vines in the covering shafts even at this temperature is explained, on the one hand, by the moisture content of the vine, which absorbs moisture from the soil, and, on the other hand, by the periodic thawing and freezing of the vine.

In this regard, patchy necrosis is more pronounced on heavy clay soils than on sandy, well-drained soils. In dry areas, where the covering layer is slightly moistened, spotted necrosis is less common.

The most severe tissue death is observed on the lower part of the arms facing the land, where there is usually more ice formation. Significant tissue damage was also noted on the arcuate bends of the sleeves, since they, being in the upper part of the covering soil, are more often exposed to sudden changes in temperature. Underground boles, as well as parts of branches and individual vines that are in the soil during the growing season, are resistant to necrosis, and therefore shoots develop on them, which can be used to restore the bush.

Control measures. Ya. Y. Potapenko (1951) and E. I. Zakharova recommend, for areas where spotted necrosis is strongly manifested, to introduce bush formations that allow you to quickly restore damaged plants and obtain stable yields. On this basis, the All-Russian Institute of Viticulture and Winemaking has developed a systematically rejuvenated fan multi-arm formation.

At the same time, it is recommended for these areas to select varieties that are able to bear fruit on young vines, including those developed from the lower buds. Such varieties are, for example, Chasselas, Pinot gray, Galan, Silvaner and some Central Asian and Transcaucasian varieties.

According to F. F. Kirillov (1953), the use of an organic cover (straw, leaves, etc.) significantly reduces the damage to bushes by spotted necrosis, since it creates an air gap that prevents the vine from freezing and freezing into the soil.

Sunburn

Sunburn of clusters and leaves is observed mainly in the southern viticultural areas during the hot summer months (July - August).

The burn of bunches happens both before ripening, and during ripening. The brushes located openly on the sunny side of the bush are subjected to burns. Under the influence of direct sunlight, the berries shrivel and quickly dry out, taking on a brown-red color, and in red varieties - a bluish-brown color. The comb also dries up. The drying process is very fast, within 4-5 days. Dry bunches remain hanging on the bush. Berries are easily burned, in which the wax coating has been erased due, for example, to rubbing them against leaves, supports, etc.

Leaves can also be burned by the sun, which form shrunken brown large spots from this. Such leaves stay on the bushes for a long time.

Control measures. To prevent burns, it is necessary to cultivate the vines on such formations that the brushes are covered with leaves and would not be directly exposed to direct sunlight.