2012-10-29

We have already repeatedly published material about various viral and mycoplasma diseases of tomatoes. Some of them can also affect other plants. Like, in particular, the cucumber mosaic virus (necrotic strain), which is one of the most harmful and widespread phytoviruses. It can infect more than 700 plant species, including parsley, dill, beans. And crop rotation will no longer help here.

On the territory of the CIS cucumber mosaic virus has become widespread both in open and closed ground. The high severity of the virus has been recorded in the North Caucasus, the Baltic states, Central Asia, Belarus, Ukraine, Moldova, the Lower Volga region, the Far East and the Krasnodar Territory. In short, almost everywhere where tomatoes and cucumbers are grown. Many people have probably seen plants infected with a virus more than once (see photo), but mistakenly thought that they simply did not have enough nutrition. No matter how it is...

Symptoms

For the first time, a necrotic strain of cucumber mosaic virus was registered in Bulgaria. The disease causes the greatest harm to cucumbers and tomatoes, causing the appearance of thread-like formations on fruits and leaves. On affected fruits, symptoms of streaking appear as brown stripes and necrotic rings. The top of the plant dies completely. The first signs of the disease appear on seedlings in the form of mosaic, zonal chloroticity, curvature and wrinkling of young leaves. As the infection process develops, the leaves wrinkle and their edges curl downwards; they acquire a mosaic coloration of alternating shapeless light green and dark green areas. Plant growth slows down, internodes are shortened, the number of flowers and leaf area decreases, and the bases of the stems often crack.

At low air temperatures, fruits on diseased plants acquire variegated, mosaic colors and often become wrinkled and distorted. Dark green areas alternate with yellow ones. Under unfavorable environmental conditions (for example, during a sharp cold snap), the flowers dry out, the stem becomes glassy, ​​and diseased plants wither.

Peculiarities

The cucumber mosaic virus is represented by small spherical particles 28-30 nm in diameter. Inactivation of the virus occurs at a temperature of 60-76°C and a maximum dilution of 1:10,000. The virus also loses its infectivity when left in juice for 6-8 days. It is also inactivated when plant residues are composted for two months. But it persists in winter in the roots of perennial host plants (sow thistle, bindweed, woodlice, quinoa, etc.). It belongs to the group of typical natural focal pathogens. In nature, the circulation of the virus is carried out with the help of aphid carriers. About 70 species of aphids are known, including melon, potato and greenhouse aphids, which can transmit the virus from wild plants to cultivated plants.

The wide distribution of the virus indicates that it does not depend on environmental factors, although the occurrence of epiphytoties is influenced by the presence of natural foci of infection and vectors. I wonder what cucumber mosaic virus lures aphid carriers to affected plants, enhancing the odor emanating from them by producing substances in the diseased plant that attract aphids. But insects, having “tasted” the leaves of such an attractive plant, discover that it is unhealthy, move to other plants and thus transmit the virus.

Aphids do not stay long on diseased plants and after some time move to healthy ones. Therefore, in field and greenhouse conditions, insect populations on healthy plants are two to three times greater than on sick ones. The cucumber mosaic virus belongs to the group of non-persistent viruses: such viruses do not linger in the body of the carrier and “travel” with it only to the first plant they encounter. They invent special propagation mechanisms that allow them to quickly infect large numbers of plants. For example, it is known that people with malaria are more attractive to the mosquitoes that carry it.

Control measures

The virus does not tolerate elevated temperatures, so infection can be avoided if the seeds are heated to 52-58°C before sowing. True, not all plants can withstand such heating. To grow seedlings, you should use composted or sterilized substrates or soil from a deep soil horizon, as we do. Infected plants should be regularly inspected and removed by the roots (they are buried deep in the ground away from the site), weeds should be destroyed as possible reservoirs of infection during the season, and especially in the off-season period. Regularly combat aphids during the growing season using biological products or pesticides such as Actellik, Aktara, etc., you can make plants unattractive to aphids by spraying them with strong-smelling substances, such as aromatic oils. Or unpleasant for pest vectors to colonize, as after spraying with ten percent skim milk.

Do not forget to disinfect knives and scissors used to trim plants with a five percent solution of potassium permanganate. Another method of protection is to grow cucumber mosaic virus-resistant varieties. Like, for example, the cucumber hybrids Pasamonte, Pasadeno, Pasalimo, Ofix, Octopus. Remember - viral plant diseases are incurable, so the main thing is prevention.

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It's a shame to lose a harvest due to unexpected diseases. Cucumber mosaic destroys entire plants (in case of severe infection) or stops the formation of ovaries. Gardeners are waiting for fruits, but there are none. They plant new seedlings: everything repeats itself.

Why is this happening? The necessary measures have not been taken, time has been lost. The summer resident should familiarize himself with the signs of the disease. Knowing the enemy by sight is half victory.

What kind of disease is this

The reason for the failure is the cucumber mosaic virus. An inexperienced gardener misses the onset of plant damage. The infection may already be present in the dacha area. A combination of several factors is required to motivate it.

Conditions for the development of the disease

The virus requires favorable conditions to activate. It starts working when:

• sudden changes in temperature;
• warming above 25 ⁰С;
• cold night.

A dormant virus awakens. The disease affects cucumbers. The infection is spread by:

• weeds;
• contaminated soil;
• dirty gardening equipment and gloves;
• seeds of a diseased plant (using your own material);
• aphids and sap-sucking insects;
• wind carrying the remains of diseased plants.

Timely disposal of cucumber vines, leaves, disinfection of soil and equipment will help reduce the risk of infection.

Plant leaves should be inspected regularly. There are several types of mosaics. A common feature: greenhouse plantings get sick, cucumbers in open ground are sometimes damaged.

Tobacco mosaic

This virus (TMV) is the most common. It affects nightshades and rarely cucumbers. It is easy to recognize the threat: you should carefully examine the plants. Signs:

• beige stains appear on the leaves of cucumbers;
• the green parts become blistered;
• the plates dry out and die;
• the fruits become ugly and change color.

The ovaries fall off. The number of fruits decreases. TMV lives in the ground for 5 years. Before opening, completely destroy tobacco plantations. Today, a gardener can protect cucumber beds.

The insidious CMV virus

CMV causes the disease common mosaic. Affects young greenhouse plants. It is easy to determine the onset based on the symptoms. The condition of the leaves should be assessed:

• the plates become marble in places;
• the color of the affected leaf successively changes to light green, dark green, yellowish;
• the edges roll down;
• the distance between the plates decreases;
• leaves become smaller;
• the plant slows down;
• the plant stem cracks lengthwise (in severe cases).

The lesion has a mosaic structure. The scale of the disease depends on the resistance of the variety or hybrid, climatic conditions (humidity and temperature in the greenhouse), and the degree of neglect. There is no treatment for mosaic on cucumbers. The gardener should prevent infection when planting.

English misfortune

The disease is caused by the CGMMT virus. This enemy is capable of destroying half the crop. Green mosaic affects young and old bushes. Plants in open ground are rarely affected. Signs of infection:

• the leaf color remains green in the first days;
• the shape and texture of the plate changes (tubercles form);
• light veins appear;
• plant growth is inhibited;
• fruits change taste (become bitter);
• cucumbers become shortened and covered with spots;
• seeds do not develop.

The disease will manifest itself a month after planting young cucumbers. Prevention and compliance with the rules of care will help to avoid plant diseases. Biologists call the green mosaic English.

Concomitant disease

Often, at the same time as green, there is a white mosaic on cucumbers. It is caused by the CV2A virus. It is activated in hot greenhouses and dense plantings. Signs of the disease:

• blurry white-yellow spots appear in the area of ​​the veins;
• then they merge and change color to white-green;
• the leaf blade becomes white or yellow;
• plant development stops.

The virus persists in plant debris, soil, and seeds. The resistance of seedlings to damage increases if the growing rules are followed.

How to fight a formidable enemy

Viral infections of cucumbers should not be treated with chemicals. When the first symptoms of the disease appear, you need to:

• remove the affected plant entirely or just a leaf;
• reduce the temperature in the greenhouse< 30 ⁰С;
• increase humidity (place containers with water, spray paths);
• disinfect the instrument;
• sprinkle the soil with ash or water with a light pink solution of manganese;
• remove weeds around.

Additionally, you should inspect the area and eliminate anthills. This will stop the spread of aphids. It transmits the infection to healthy plants. Some gardeners remove the soil along with the affected bush. It is replaced with healthy soil. Sick plants should be burned.

It should be remembered: the English mosaic virus is resistant to changes in external conditions. It remains survivable when the temperature rises to 90 ⁰C, freezing, drying.

Restoring favorable conditions in the greenhouse will slow the spread of the disease. To consolidate the result, you need to treat the plantings with serum (1 part to 10 parts water).

Prevention of infection development

A competent gardener knows: it is easier to prevent them than to treat them later. To preserve the cucumber harvest and save your own time and effort, you need to follow simple advice from agronomists:

• Monitor the condition of the soil in the greenhouse. Remove dead parts of plants. They accumulate the virus.
• Mosaic is a disease of cucumbers, but the virus overwinters well on the roots of harmful plants. Weeds need to be pulled out regularly. The infection nests in the underground part of thistle, wheatgrass, and woodlice.

• Plant plants according to the norm (the seed manufacturer indicates the diagram on the bag). Remove side shoots (if the type of fruiting on side shoots is not indicated).
• Apply fertilizing as recommended by the manufacturer. Do not overuse fresh organic matter (nitrogen).
• Cucumbers do not tolerate drafts. To cool the air in the heat, you should whitewash the greenhouse or cover the plantings with white non-woven material.
• Avoid sudden changes in daily temperatures. To do this, it is enough to place several basins of water in the greenhouse. During the day, the liquid cools the air, at night it warms it.
• Monitor air humidity. Basins of water and spraying of paths will help.

• Observe the rules for the circulation of vegetable crops. Cucumbers, zucchini, pumpkins, watermelons are bad predecessors for cucumbers. Nightshades (tomatoes, peppers), cruciferous vegetables (radishes, turnips), legumes (peas, beans) are good.
• Regularly green the soil. Planting oats, rye, vetch, and mustard will improve the health of the top layer of soil. Seedlings must be embedded in the ground when digging.
• Inspect the area in the spring. Destroy the discovered anthills: the ants resettle the aphids. Blood-sucking insects carry the virus.
• Spray the plants with a solution of green soap against aphids. An infusion of garlic helps well (pour 1 grated clove with a glass of boiling water, leave, dilute with 2 liters of water).
• Factory seeds do not require processing. You must warm up your own for 3 days at a temperature of 50 ⁰C (or a day at 60 ⁰C).

• Hygiene is also needed in the garden. Wipe the instrument regularly with vodka, alcohol, and red manganese solution. Wash gardening gloves frequently.
• Plant only healthy seedlings. Twisted stems and unusual leaves are suspicious. Such seedlings are discarded. Destroy diseased plants immediately. Disinfect the soil with a solution of copper sulfate or heat it over fire.
• Planting melons and melons should not be placed next to the greenhouse. During pollination, insects can transfer infected pollen to healthy plants.
• Cucumbers rejoice in the addition of compost. Only fully mature organic matter (3 years old) should be applied to the beds.

The most important thing: choose virus-resistant varieties and hybrids. The seed manufacturer must provide information about this on the label.

Gardeners treated the plantings at the initial stage of the mosaic with a disinfectant solution: stir 1 liter of whey in 10 liters of water, add 15 drops of iodine. Cucumbers were sprayed leaf by leaf. The spread of the disease stopped. But it was not possible to save the affected plants.

Diseases of cucumbers in greenhouses and open ground are numerous and varied. In greenhouse conditions they are much more common and their harmfulness is much higher than in open ground. How to prevent disease and cure already diseased cucumbers is described in detail in this article.

Powdery mildew or ash The disease appears on the leaves of cucumbers. The disease is very harmful to greenhouse cucumbers, where it spreads instantly. In open ground it is less common and spreads less rapidly. The causative agent is a pathogenic fungus oidium, it belongs to a different order than the causative agent of powdery mildew on currants and gooseberries. The pathogen overwinters on plant debris. Infestation can occur throughout the season. Primary outbreaks appear near doors and windows, in open ground - in the most moist and shaded places. The cucumber disease spreads very strongly at high humidity and strong temperature changes in the greenhouse. On the street, the first outbreaks appear 3-4 days after heavy rains. Another name for the disease is ashtray. Description of the disease. A white coating appears on the leaves, stems and petioles and spreads quickly. The spots gradually merge and darken, becoming dirty gray or ashy in color. The leaves become wavy, their edges bend downwards and gradually dry out. After a few days, the affected leaf dries out, and the disease spreads to the upper leaves. With strong spread, individual lashes dry out first, and then the entire plant dies. Greens are not affected by ash grass, but as the disease develops they become smaller and become bitter. The spread of the disease is facilitated by sharp fluctuations between day and night temperatures, as well as prolonged cold weather and dampness. Treatment of the disease Treatment of cucumbers in a greenhouse should begin immediately. At the first signs of the disease, cucumbers are sprayed with any of the following preparations: Ordan, Quadris, Topaz, Bayleton, Topsin-M, Tilt. After 14-20 days, repeat spraying is carried out (the specific period depends on the period of the protective effect of the drug). It is better not to use colloidal sulfur and preparations based on it on cucumbers (and other pumpkins). Firstly, they are not used in cold weather (temperatures below 20°C), since the drugs are ineffective under such conditions. Secondly, at the slightest excess of concentration or in sunny weather, severe burns occur on the leaves and vines. Use of the biological drug Alirin-B at an early stage of disease development. It is non-toxic, and greens can be harvested 2 days after treatment. When treating plants, they are never sprayed twice with the same preparation, since the pathogen develops resistance extremely quickly. Folk remedies for treating illness Spraying cucumbers with milk or kefir (1 l/10 l of water). Lactic and lactic acid bacteria are antagonists of pathogenic fungi and suppress their growth and development. Iodine treatment. 10 ml of 5% alcohol solution/10 l of water. Carry out double treatment with an interval of 7 days. Both iodine and alcohol are antiseptics and cause the death of pathogens. Effective at the initial stage of the disease. A strong solution of potassium permanganate, dark pink in color. Carry out 3-fold processing. Treatment with soda ash. 1 tbsp. dilute in 2 liters of water, add soap as an adhesive and process the cucumbers. Whatever means of control are used, the affected leaves must be torn off and burned. Prevention Cleaning up all plant debris. Disinfection of greenhouses before sowing seeds. Removing weeds around the perimeter of greenhouses or cucumber beds. The pathogen can persist on them. Growing resistant varieties: Boy with Thumb, Geisha, Gostinets, Golubchik, Krokodilchik, Murashka, Octopus. Cucumber varieties that are completely resistant to powdery mildew have not yet been developed. Downy mildew or peronosporosis Disease on cucumber leaves in a greenhouse. The causative agent is the fungus peronospora. differs from the real one in that its mycelium (mycelium) develops on the underside of the leaf, and spots appear on top. The spots themselves, unlike ashtray, are yellow or brown. The disease most often affects greenhouse cucumbers. Its spread is favored by high humidity and cold nights. It most often appears in late July-early August, but can appear earlier. It is stored in the soil for 6-7 years. Signs of defeat. The disease appears on the leaves of cucumbers. Numerous irregularly shaped yellow-oil spots appear on the upper side of the leaves. Within 5-7 days, the spots enlarge and turn brown. On the underside, the mycelium is a white-purple coating. The leaves dry out within 2-3 days. If the disease on cucumbers is not treated, then in a week it can destroy the entire greenhouse. Methods of treating the disease Stop watering and ventilate the greenhouse well. Remove all affected leaves. Sprinkle the soil under the plants with ash to prevent the spread of the pathogen. Treatment with Previkur, Consento, Revus. Use of preparations containing copper: Abiga Pik, Ordan. Bordeaux mixture is ineffective in the fight against peronosporosis. Spraying with biological products: Trichoderma, Gamair. Folk methods of struggle Spraying with a bright pink solution of potassium permanganate. 25 g of soda ash is dissolved in 5 liters of hot water, 5 g of tar soap is added. Cucumbers are sprayed at the initial stage of the disease. All spraying is carried out on the underside of the leaves. Prevention If cucumbers are planted in the same greenhouse from year to year, then fungal spores accumulate there in large quantities. In early spring, remove the top layer of soil, replacing it with fresh soil. Preventive spraying of cucumbers with biological products Fitosporin and Gamair. The interval between treatments is 5-7 days. Growing varieties resistant to downy mildew: Affin, Golubchik, Octopus, Pekti, Ekipazh. Prevention is a fairly effective method. It reduces the risk of disease development on cucumbers in a greenhouse by 1.5-2 times. Bacteriosis or angular spot The causative agent is a bacterium from the genus Pseudomonas. Preserved on plant debris and in seeds. The development of the disease is promoted by high humidity and temperature. It most often affects greenhouse cucumbers. In closed ground, you cannot water the crop with rain, as drops of water on the leaves contribute to the spread of infection. Description of the disease The disease affects leaves, fruits and seeds. The disease on cucumbers can appear during the entire growing season, including during the germination phase. The disease appears on the leaves and then spreads to green plants. If cucumbers are not treated, the plants die both in the greenhouse and in the open ground How to treat bacteriosis Despite the fact that the causative agent of the disease is of bacterial origin, it is treated with fungicides (antifungal drugs). They are quite effective. The most effective against bacteriosis are copper preparations: Kuproxat, Bordeaux mixture, Abiga Peak. The greens should then not be eaten for 20 days. Use of the biological product Fitolavin. It belongs to phytoantibiotics (biobactericide) and completely destroys the causative agent of the disease. To prepare a working solution, 2 ml of the drug is diluted in 1 liter of water, the consumption rate is 10 l/100 m 2. The solution is used only fresh, it is not stored. When feeding, increase the dose of potassium fertilizers or make additional potassium fertilizing. There are no effective folk remedies. Prevention When the first signs of disease appear on cucumbers, watering is reduced and greenhouses are constantly ventilated. Air humidity should be reduced to 80-85%. The air, soil and plants must be dried. Collection and destruction of plant residues. If bacteriosis appears in the greenhouse, it is advisable to replace the soil in the fall. Anthracnose The disease usually accompanies bacteriosis. It affects all above-ground parts of the plant: leaves, vines, greens. It appears in the second half of summer; greenhouse cucumbers are particularly affected by anthracnose. The causative agent is a fungus that survives on plant debris. Signs of illness. The disease initially affects the leaves. Vague, rounded brown spots appear on them, which then merge. Most of the leaf takes on a burnt appearance. and crumble. Orange mucous pads may appear on the vines and stems. Leaves of cucumbers suffering from anthracnose. Later, anthracnose affects young greens. Brown sores with hard edges appear on them. They are very similar to bird bites. Affected cucumbers are unsuitable for food. Treatment of the disease The fungus attacks cucumbers especially hard in hot and humid summers. In a greenhouse, crops get sick more often than in open ground. At the first signs of disease, the affected parts of the cucumbers are removed and burned. At an early stage of development, treatment with biological products is quite effective: Alirin B, Fitosporin. Spraying cucumbers with copper preparations. It is advisable to do preventive spraying after the appearance of 5-6 leaves. Then the likelihood of cucumbers being affected by anthracnose is noticeably reduced. Copper has a good healing effect, but after processing greens cannot be eaten for 20 days. Simultaneously with spraying, watering is carried out with the same preparations, since the pathogen persists on the soil and lower yellowed and fallen leaves. Prevention Disinfection of greenhouses in autumn. In the greenhouse, a sulfur bomb is set on fire, and 3-5 days after this, the ground is spilled with copper sulfate (1 tablespoon per 10 liters of water), or a dark crimson solution of potassium permanganate. You can sprinkle the ground with bleach, and after a week dig it up with a shovel. But this should only be done in the fall. In the spring, you can also set fire to a sulfur bomb. Boiling water is poured onto the ground several times. During the growing season, carry out 2-3 preventive sprayings with copper-containing preparations. Destroy weeds around the cucumber plot, as they can also be affected by anthracnose. Constantly ventilate the greenhouse. It is especially necessary to do this in the early morning, when dew appears on the leaves of the cucumbers. Anthracnose is easier to prevent than powdery mildew or downy mildew. White rot The causative agent is a pathogenic fungus. Greenhouse cucumbers usually get sick. It is quite rare when growing cucumbers in open ground. The spread of the disease is facilitated by high air and soil humidity and insufficient ventilation of greenhouses. Watering with cold water and sudden changes in temperature provoke the disease. The fungus is preserved on plant debris. Signs of defeat. Flakes of a white fluffy coating resembling cotton wool appear on the leaves, petioles, vines and green shoots. Black spots of sporulation later appear on it. The affected areas become soft and slimy. If measures are not taken, the plant dies. How is the disease treated? Spraying cucumbers with copper preparations: Ordan, HOM, Bordeaux mixture. The lash below the affected area is cut off with pruning shears and burned. The cut is treated with chalk, coal, and ash. All affected green plants are removed. At the onset of the disease, treatment of cucumbers with biological products is effective: Gamair, Alirin B, Glyokladin, Planriz. Feed the plants with nitrogen fertilizers with the addition of copper sulfate on the tip of a knife. Traditional methods of treatment The plaque is removed manually, and the stem is treated with a light pink solution of potassium permanganate. When there is high humidity in the greenhouse and the threat of disease, cucumbers are sprayed with a milk solution. 1 liter of milk per 10 liters of water, add soap to the working solution as an adhesive. Prevention Thorough ventilation of the greenhouse every day. If the nights are warm, then the greenhouse is left open at night. Reduce watering. When the disease appears, cucumbers are watered rarely, but abundantly. Timely collection and destruction of diseased leaves. Every 2 weeks, remove the bottom 2 leaves from the cucumbers. This prevents excessive soil moisture and prevents the occurrence of diseases. Brown (olive) spot or cladosporiosis A fungal disease. Most often occurs in greenhouses. The main cause of the disease is sprinkling of cucumbers with cold water, as well as cold weather (10-13°C day and night). The pathogen persists on plant residues and in soil; it tolerates unfavorable winter conditions well. Therefore, when growing cucumbers in greenhouses, when a disease appears, it is necessary to change the soil and disinfect the greenhouse. Signs of the disease. It most often affects young green plants, less often leaves. Brown and dark brown sores appear on green plants, releasing droplets of cloudy liquid. Gradually, spots cover the entire fruit, and it becomes inedible. Small dark brown spots appear on the leaves, which gradually merge. How to treat Treatment with copper preparations. Ventilation of the greenhouse. At the very beginning of the development of the disease, treatment with biological preparations Fitosporin, Pseudobacterin, Gamair. Prevention Do not water cucumbers by sprinkling. Water only with warm water. Timely harvesting of all affected fruits and leaves. It is advisable to perform crop rotation in the greenhouse. Growing resistant varieties: Amur, Alphabet, Amazon, Valaamsky, Dobrynya, Green Wave, Pogrebok, Five Stars. Cladosporiosis on cucumbers is very harmful and difficult to treat. If you do not take measures, you may be left without a harvest. Gray rot The disease is caused by pathogenic fungi that live in the soil and on plant debris. Affects stems and fruits. The appearance of the disease on ground cucumbers is facilitated by low night temperatures, watering with cold water, poor ventilation and dense plantings. With strong thickening, the varieties develop a huge amount of barren flowers, the pedicels of which are affected first. Description of the disease. On the lashes, especially at the branches, in the axils of the leaves, gray slimy spots with a gray smoky coating appear. The spots quickly merge, covering large areas of the stem. On fruits, the disease begins at the spout (where the flower was). A smoky coating quickly covers the entire fruit, it becomes slimy and falls off. Control measures At the initial stage of the disease, treatment of cucumbers with biological products Gamair, Alirin B, Planriz. Treatment with Bayleton. Spraying with Euparen before fruiting begins. The drug cannot be used during the fruiting period. The solution should not be mixed with Bordeaux mixture and no adhesives should be added. Timely removal of affected plant parts. Traditional methods of treatment Spraying with a mixture of ash (1 cup), chalk (1 cup), copper sulfate (1 tsp), per 10 liters of water. Water the cucumbers with the same solution. Spraying with iodine solution. 10 drops of the drug per 10 liters of water. It is used for both prevention and treatment of the initial stage of the disease. Treatment with a pink solution of potassium permanganate helps quite well with all types of rot. The treatment is repeated after 4-6 days. Spraying cucumbers with tar infusion. Tar soap (20 g) is dissolved in 10 liters of water and treated. All folk remedies are used mainly for prevention. If the first signs of the disease appear, you need to move on to treatment with biological products. Preventive measures Do not thicken the crops. Humidity reduction up to 80%. Regular ventilation of the greenhouse. Timely removal of lower leaves. Collection and destruction of diseased greens. Remove barren flowers in a timely manner. If the rules of agricultural technology are followed, gray rot usually does not appear in greenhouses. Fusarium The causative agent is pathogenic fungi. Cucumbers get sick mainly in greenhouses. The pathogen persists for a long time in the soil and on plant debris, as well as in seeds. The disease spreads in cold weather with soil temperatures below 18°C ​​and high humidity. Signs of defeat. It affects the roots and basal part of the stem. Penetrates into the roots through root hairs and wounds. The first signs are the withering of individual leaves at the top of the stem, gradually withering goes down, covering the entire stem and neighboring vines. The cucumbers look like they haven't been watered for a long time. A pink coating appears on the stems at the very surface of the soil - sporulation of the fungus. Along with wilting, the root part of the stem rots. If you dig up the ground, you will find that the bark on the roots and root collar is cracked, and the roots themselves become brown and die. On a cross section of the root collar, browned vessels are clearly visible. How to treat the disease At the very beginning of the disease, when the leaves droop with sufficient watering, biological products help well. Cucumbers are watered with a solution of one of them: Pseudobacterin, Glyocladin, Trichocin, Planriz, Trichoderma. Simultaneously with watering, the root part of the stem is sprayed. The treatment is repeated after 5 days. Watering plants at the roots with Previkur. Once the disease has fully developed, the cucumbers cannot be saved. Diseased plants are removed and the ground is sprinkled with bleach. Neighboring cucumbers are treated for preventive purposes. Prevention. When fusarium appears in the greenhouse, the soil is completely replaced. If this is not possible, then sprinkle it with bleach, and after 3 weeks, dig it onto the bayonet of a shovel. It must be remembered that the causative agent of fusarium is very resistant to unfavorable conditions and remains viable for up to 7-9 years. Since fungal spores are stored in the seeds, all seeds must be treated before sowing, otherwise cucumbers will have to be treated for this disease again. Cucumber mosaic virus This is what diseased leaves look like with cucumber mosaic. The causative agents are a group of viruses that cause various manifestations of the disease. In addition to cucumbers, viruses infect tomatoes, sweet and hot peppers, lettuce, beans, cabbage, currants, raspberries and about 700 more cultivated and wild plants. The virus persists on plant debris and in the roots of weeds for several decades. Viral diseases mainly affect greenhouse cucumbers. In open ground, the disease practically does not occur on crops. The disease is very dangerous; if no action is taken, it can appear on most garden crops, as well as on shrubs. There are 2 types of pathogens found in summer cottages: green mottle virus and mosaic virus. Crop losses are up to 50%. The virus affects crops growing with cucumbers in the same greenhouse (except eggplants). Cucumbers are affected throughout the growing season, starting from germination. The virus is spread by seeds. It is also transmitted from diseased plants to healthy ones by contact when caring for cucumbers. Description of the disease. The disease may not appear on cucumbers for a long time. The first signs appear after a sharp rise in temperature above 30°C. The veins on the leaves take on a yellowish tint. Pale yellow streaks or spots appear along them, which then spread to the entire sheet. Dark green and yellow-silver spots appear. Leaves become deformed and die. The same spots and streaks appear on the greens. Some strains of the virus cause deformation of fruits. Cucumbers become shortened and bitter; the seeds of the varieties do not develop, but remain in their infancy. The source of infection is contaminated seeds. The virus is actively transmitted by aphids. In winter, it persists on weeds (woodlice, sow thistle, quinoa), as well as on infected currant and raspberry bushes. Signs of defeat. The earliest signs may appear during the germination period, but usually the first symptoms appear during the growth of the vines. Yellow and dark green spots appear on diseased leaves, the leaf becomes lumpy, corrugated, wrinkled, and its edges bend down. Around the veins the color may turn dark green. A leaf affected by ordinary mosaic. The greens become speckled or striped and, if severely damaged, become wrinkled. Dark green areas become convex, and areas with normal or light color become depressed. Fruits are especially severely deformed when the temperature drops to 17-19°C. On the vines, the internodes are shortened. The growth of lashes stops. If the first signs of the disease appear in the second half of summer, then the cucumbers are not so damaged. Anti-virus measures When the first signs of infection of cucumbers (and other cultivated plants and shrubs) appear, they are treated with the drug Farmayod, which has a strong antiviral effect. The drug is sold in garden stores. You can use its analogue Povidone iodine. After treatment, you should not water the cucumbers on the leaves and allow condensation to form in the greenhouse, since the preparation is easily washed off from the treated surface. In case of severe infection, diseased cucumbers are removed and burned, the rest are treated with Farmayod. Disease prevention Mow all weeds around the perimeter of the site. It is not recommended to plant other pumpkin crops nearby, as the virus is transmitted through water, soil, and when plants come into contact with each other. Destruction of aphids in a summer cottage. Growing virus-resistant varieties: Alphabet, Ozornik, Nezhinsky, Merry Friends. Complete replacement of soil in the greenhouse. The cucumber mosaic virus is very dangerous. If after the first treatment of cucumbers the symptoms of the disease continue to increase, then the plant is removed. Sometimes you have to completely destroy all greenhouse cucumbers; here you have to choose between preserving the plants and the very high risk of infecting shrubs and trees. You might be interested in:

The mosaic, having affected cucumbers, also spreads to other garden crops - cabbage, tomatoes, peppers, beans, lettuce... How to save garden plants?

Cucumber mosaic viruses infect the plant at the cellular level, and they are transmitted by aphids. The mosaic virus is well adapted to our harsh winters. It can live safely in soil or plant debris for years. Under favorable conditions, the virus begins its destructive work. The disease can affect a plant at any stage of its development.

Seedlings affected by mosaic grow very slowly and eventually become unsuitable for transplanting into the ground. If the disease occurs at the stage of fruit ripening, then it will affect not only the leaves, but also the cucumbers. What the affected fruits look like can be seen in the photo.

Have questions?

Ask and receive useful advice from professional gardeners and experienced summer residents.

Cucumber mosaic is detected by the appearance of mottling on the leaves. Soon after the first signs appear - spots consisting of densely located dots, the leaves begin to curl and then fade.

Types of cucumber mosaic

Several types of this disease occur in our area.

- Tobacco mosaic. This disease has been studied by botanists for a long time. Most often, tobacco mosaic affects sweet peppers, tomatoes and tobacco. It does not occur very often on cucumbers. Externally, tobacco mosaic looks like a marble pattern with streaks of bright green and pale yellow. They appear on the leaves. In this case, the unaffected parts of the leaves swell, after which the leaf falls.

- Ordinary mosaic often occurs on greenhouse cucumbers, although in the south it also affects ground cucumber plantations. The common cucumber mosaic manifests itself as small white spots on the leaves. Later there are more of them, they become larger. This causes cucumber leaves to become hard and wrinkled. Next, the edges of the affected leaves begin to curl. Further development of the disease leads to a stop in the growth of the cucumber vine. At this time, the flowers die, a new ovary does not occur, and tuberosity appears on the ripening cucumbers. An ordinary mosaic can destroy a cucumber vine in 2 weeks.

- Green speckled mosaic. The virus of this variety develops immediately after planting seedlings in the ground. However, the disease can occur later. It manifests itself as swelling of the leaves and light yellow spots that appear between the leaf veins. A cucumber vine affected by a speckled mosaic stops growing, its leaves become deformed, and some of its flowers fall off. Spots appear on cucumbers. Then the fruits become deformed and acquire a bitter taste.

- White mosaic It almost does not show itself on cucumbers in the initial stage of development. Only a very experienced gardener will be able to notice the tiny pale yellow dots on the leaves. Then they begin to enlarge and change their color to white, and the spots look like rings or angular circles. If you do not take rescue measures, then soon the entire surface of the leaves will turn white, and they will soon fall off.

Favorable conditions for the development of the disease

Cucumber mosaic viruses can live on cucumbers for a very long time without manifesting themselves. In this case, the cucumber vine develops normally. However, under certain conditions, the virus begins to actively multiply, which causes the disease.

The following conditions are favorable for the development of the disease:

• sudden changes in ambient temperature during the day and night;
• reduction in ambient temperature to 13 degrees;
• increase in ambient temperature to 32 degrees and above;
• poor watering from which the plant does not receive enough nutrients and is unable to resist the disease;
• excessive watering, from which the plant does not receive enough oxygen and also weakens;
• underdevelopment of the plant root system;
• improper feeding or lack thereof.

Where can a viral infection come from?

Alas, even if all the rules of agricultural technology are followed, a mosaic on cucumbers can still appear. This applies to both ground and greenhouse plants. Cucumber mosaic viruses can enter plants through work equipment. They can also be delivered by insects or birds. One of the reasons may be careless weeding of the plantation. Viruses thrive in weeds. Finally, viruses can enter cucumber seedlings through untreated seeds.

Often the cause of the appearance of cucumber mosaic is careless disinfection of the soil on which plants with mosaic previously grew. That is, in such a situation, the infection does not reappear, but continues after the winter break.

How can you cure cucumbers?

Treatment of cucumber mosaic should begin with restoring favorable conditions for the growth of cucumbers. These are the conditions that are not comfortable for the virus. If you grow cucumbers in greenhouses, immediately return the temperature to normal and regularly ventilate the greenhouse.

Stop watering diseased ground cucumbers for two or three days, and use spraying instead. If the weather is dry, place several buckets of water on the site. This will help to obtain sufficient air humidity.

Be sure to disinfect all working tools with which you work in the garden. They can be treated with boiling water, a strong solution of potassium permanganate or industrial alcohol.

Remove any weeds that have appeared between the cucumber vines.

Severely affected cucumber vines should be uprooted and burned. Sprinkle the resulting holes with wood ash.

All these control measures are not treatment, but are intended to stop the development of the disease. It can be completely eliminated only with the use of special means.

Drugs

The cucumber mosaic virus instantly adapts to chemicals. Of course, some microorganisms die under their influence, but a considerable part survives and acquires immunity against them. Even worse, this immunity is inherited.

Folk remedies

Treating cucumbers with a whey solution gives excellent results. With this simple remedy, cucumbers can be sprayed repeatedly until they are completely cured. This solution is good for early disease in cucumbers. To enhance the effect, you can add a few drops of iodine.

Infusions of dandelion, aromatic tobacco, garlic or onion peels have a detrimental effect on cucumber mosaic viruses.

Preventive protective measures

To radically reduce the threat of mosaic infection of cucumbers, the following actions should be taken:

• after weeding, do not leave weeds on the site;
• Do not plant cucumbers for two years in a row in one place:
• in late autumn, burn all plant debris in the garden;
• do not plant cucumbers too thickly:
• do not use old ropes to tie cucumber lashes;
• systematically disinfect work equipment;
• Monitor the microclimate in the greenhouse and do not allow it to deviate from the norm:
• strictly follow the rules of watering and feeding cucumbers;
• annually update the top layer of soil in greenhouses to a depth of at least 10 cm;
• Spray seedlings planted in the ground with Farmayod solution.

Grow cucumber varieties that are more resistant to mosaic. Before buying seeds, ask the seller about this.

At different stages of plant growth, including cucumbers, there is a danger of them being affected by various diseases. Diseases of cucumbers are of various types (fungal, bacterial, viral infections), and the most dangerous period is the flowering of the plant. Therefore, it is very important to take appropriate measures at the first signs of any disease and preserve the plant, giving it the opportunity to develop normally.

The first signs of cucumber diseases are white or yellow spots on the surface of the leaf, as well as their drying out. More complex symptoms of a progressive plant disease are weakness of the vines, lethargy of the leaves, and softness of the fruits.

The danger of diseases is that they can lead to the rapid or slow death of the bush as a whole.

It is very important to correctly identify the disease, since the salvation of the plant directly depends on this. Many summer residents also note that prevention is the best way to combat cucumber diseases (in a greenhouse, in open ground, on a windowsill).

It is necessary to know everything about cucumber diseases (see photo) in order to prevent the development of the disease, or to eliminate it correctly and get a good harvest of your favorite vegetable crop.

What diseases of cucumbers exist and how to treat them?

As practice shows, both the plant itself, starting with the leaves or root system, and the fruits are affected by the disease. Diseases of cucumbers are common both in open ground and in greenhouse conditions. Cucumber seedlings are also not protected from diseases.

Naturally, plants in open ground are less protected than in closed beds. A certain microclimate has been created in the greenhouse, which inhibits the spread of various infections and has a beneficial effect on the growth of cucumbers. Limited space also plays a huge role in disease prevention.

The most common diseases of cucumbers:

• Powdery mildew.
• Powdery downy mildew.
• Olive spot (cladosporiosis).
• Common field mosaic.
• Green and white mosaic mottled.
• Root rot.
• Gray rot.

Powdery mildew on cucumbers

Signs of powdery mildew on cucumbers (see photo) are small brown spots covered with a white coating (also called mycelium). At first a small area is affected, but over time the disease covers the entire leaf. It gradually becomes dull and dries out completely. Cucumber seedlings affected by this disease do not develop, and the formed young shoots no longer grow.

How to fight powdery mildew on cucumbers? Protection is carried out by preparing a solution of weeds. To do this, you will need the following material: plantain, coltsfoot, nettle, dandelion, wood lice, fireweed. All plants are crushed, placed in a bucket (usually the capacity is 10 liters) and filled with hot water. Next, add one teaspoon of urea, manganese powder, liquid soap and mix everything. And if the question arises - how to treat cucumbers against powdery mildew and other diseases, then the resulting solution is the best option for plant protection.

In addition to a natural herbal cocktail for powdery mildew on cucumbers, folk remedies are used - whey and a mixture of mullein and urea in a proportion of 10 liters. water/1 kg cow dung with 1 tbsp. spoons of urea.

To prevent powdery mildew on cucumbers, use fine sulfur powder (the soil is pollinated through three-layer gauze and covered with film for 3 hours). Also, when fighting powdery mildew on cucumbers, use a decoction of horsetail.

Preparation of tincture: 100 gr. dried or 1 kg of fresh horsetail is infused for about a day in 10 liters of water, then boiled for about 2 hours. After boiling, the broth should be cooled and diluted with water in a ratio of 1:5.

In this way, the process of growing cucumbers can be significantly improved. Diseases are eradicated, and the soil becomes quite suitable for the safe growth and fruiting of plants.

Advice! To prevent disease, diseased leaves and shoots should be burned immediately. Throwing them on the edge of the garden or bed is not recommended.

How to deal with downy mildew (peronospora)?

The main sign of downy mildew on cucumbers (see photo) are yellow-green spots that cover most of the leaf. They are also mistaken for traces of acid rain. A purple-gray coating appears at the bottom of the leaf, as a result of which it dries out completely and crumbles. Downy mildew of cucumbers affects plants regardless of age. It is typical in most cases when growing cucumbers in open ground.

The prerequisites for the occurrence and development of peronosporosis are high humidity and air temperature up to 16-18 0 C. The disease develops from small droplets on a leaf.

Spores are able to maintain their dangerous vital activity in the soil for a long time, so it is very difficult to fight them. If peronosporosis or downy mildew appears on cucumbers, then control measures should include the use of certain preparations containing copper (Bordeaux mixture, Ridomil Gold, Oxychom). These products are effective as a prophylactic agent.

If cucumbers are affected by downy mildew, then treatment is carried out with the drug “Rizoplan”. It is based on living cells of certain bacteria. They are absolutely harmless to humans, but are destructive to downy mildew spores. The drug also does not accumulate in the soil, but decomposes immediately.

In addition to traditional preparations, you can also use a folk remedy for downy mildew on cucumbers - whey. The leaves are sprayed with it.

How does olive spot (cladosporiosis) appear on cucumbers?

The occurrence of olive spotting on cucumbers (see photo) should be observed in the second half of summer, when the cucumbers have already fully formed the bush. Olive spot appears on fruits in the form of olive (brown) spots with a coating. The disease spreads quickly and if left untreated, the entire crop can be lost.

This type of disease is more typical for greenhouse conditions. Cladosporiosis spores are resistant to the greenhouse microclimate, so control of this disease should be started immediately.

If olive spotting of cucumbers is observed, then control measures should include thoroughly wiping all surfaces of the greenhouse with a disinfectant that does not contain chlorine. Under no circumstances should you water cucumbers with cold water, and when the disease is first detected, you should stop watering the plant altogether for 3-4 days.

Treatment of cucumber disease in open ground is carried out by using solutions that contain copper - Bordeaux mixture with the addition of liquid soap.

In order to prevent the appearance of olive spot, crops should be changed in the affected areas.

What is the common cucumber field mosaic?

Common cucumber mosaic (see photo) most often develops in open soil. Signs of the disease are yellow-green spots in the form of a mosaic. As the disease progresses, the leaves of cucumbers curl, become dull, dry out and fall off. The fruits become very pimply. Under the influence of the disease, the plant’s immunity weakens so much that when the air temperature sharply drops, the bush simply stops growing and soon dies.

The danger of this disease lies in its resistance to cold. Spores of the common field mosaic easily survive winter and cold in the root systems of reserve plants (sow thistle, quinoa, woodlice, bindweed, wheatgrass). These are difficult to remove weeds, so it is very difficult to fight this virus. You can use the method of growing cucumbers in plastic bottles. It is absolutely not complicated and plants are not affected by field mosaic in 94% of cases.

How to spray cucumbers against illness? For ordinary cucumber mosaic, treatment consists of spraying the bushes with whey. In especially severe cases, this is done with a concentrated substance, and in preventive measures and in the initial stages of the disease, the serum should be diluted with water in a ratio of 1:2. Treating cucumbers against diseases with folk remedies very often gives a positive and lasting result.

Green and white mosaic mottled

Green and white cucumber mosaic (mottled) is one of the most common infections. Signs of the disease are wrinkled leaves with blown out areas, and areas with a green or white color also appear. The spots become white as they progress. In this case, it is very difficult to fight the disease.

At an advanced stage, cucumber bushes dull their growth. The leaves weaken and begin to wither in places. The fruits, accordingly, become very soft and their taste deteriorates. An outbreak of the disease can be triggered by a sharp increase in temperature from 22 0 C to 30 0 C.

This dangerous viral disease is transmitted through untreated tools, plant debris, and simply persists in the soil. To combat this disease, gardeners choose varieties that are resistant to the disease (mostly hybrids for open or closed ground).

The best way to get rid of this cucumber disease is care. It is necessary to remove affected shoots and leaves in a timely manner and burn them immediately. Also, for prevention, you can spray the bushes with a light whey solution.

How to deal with gray cucumber rot?

Gray rot on cucumbers (see photo) is a type of viral disease that appears during the period of active fruiting. A gray coating may appear on leaves, stems and fruits, especially in the internodes. The most favorable environment for its development is a densely planted area of ​​​​a vegetable garden or garden bed.

The fact is that cucumbers that grow in close proximity to each other begin to rot due to the inability to develop in close quarters.

How to deal with gray rot on cucumbers? The therapeutic measure is the timely removal of diseased leaves and entire sections of the stem. In some cases, it is necessary to remove the entire bush. The fight against gray rot on cucumbers also involves applying a specially prepared substance (chalk with potassium permanganate) to the wounds of the removed leaves. The consistency of such a remedy should be viscous and have a light pink tone.

Root rot of cucumbers

The danger of root rot of cucumbers (see photo) is that signs of the disease are not immediately visible, since it affects the root system of the plant. The first sign of this disease is a sharp wilting of the bushes. In this case, you cannot start watering the plant, this will harm it even more.

How to save cucumbers from root rot? In the early stages of the disease, you should slightly expose the root system (to do this, you need to lightly loosen the soil around it). Treatment for root rot of cucumbers involves sprinkling the affected parts with a specially prepared mixture (charcoal, chalk and ash). A solution of copper sulfate and copper oxychloride can also help against root rot of cucumbers.

After treatment, the roots and part of the stem should be sprinkled with clean, dry and unaffected soil. Watering can begin at the first sign of improvement in plant growth.