Diseases of cucumbers: a description with photos of 14 main problems, as well as ways to treat them | + Reviews

Symptoms: The appearance of white bloom first on the lower, then on the upper side of the leaves. Subsequent spread to stems, flowers; the last to “whiten” the fruits. Over time, the fluffy white bloom darkens, the leaves are deformed and dry.

Appearance time: The second decade of July - the end of August.

Cause: Mushrooms of the Odium family. The mycelium of the fungus cannot exist outside the culture. Spread occurs with drip moisture.

Consequences: The defeat of the whole plant. At the same time, it does not die, but begins to lose moisture, resulting in low yields.

Ways to fight: Disinfection of plants and soil. Sometimes spraying with copper sulfate is not enough. Recommended measures include:

1. The use of antibacterial drugs: Baktofit or Pseudobacterin
   

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2. The use of chemicals (Topaz, Prevent, Oksihom, Karatan, Bayleton). Their use must be carried out exactly according to the instructions.
   

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3. Soil treatment with sulfur: watering 10 sq. m solution containing 30 grams (2 tablespoons) colloidal sulfur powder per bucket of water
   

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4. The use of potash mineral fertilizers
   

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5. Limiting the use of organic nitrogen fertilizers (dung or mullein). Compost and rotted manure can not be limited.
   

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6. The use of folk remedies: cucumbers are sprayed with a solution of sodium bicarbonate (soda), it is diluted at a concentration of 0.4% with the addition of soap (5-10 g per 1 liter). As a preventive measure, it is recommended to spray the plants with an infusion of onion peel.
   

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7. The following recipe is effective for spraying: a solution of 1 ml of iodine and 15 ml of liquid soap in 1 liter of skimmed milk or whey
   

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8. You can use an infusion of garlic. One head of garlic, along with the husk, is poured with 1 liter of boiling water and insisted for several hours. Spray the diseased plants with the resulting composition for 1-2 weeks daily. Sometimes 10-15 g of liquid soap is added to the infusion.

As a preventive measure, soil treatment is recommended before planting. Also, to avoid the disease, it is recommended to use powdery mildew-resistant varieties and hybrids.

Symptoms: The surface of the leaves (the upper part of the plate) is covered with light yellow spots. After some time, the spots merge into larger ones, then the whole plant is affected, watery purple spots are observed from the lower part of the plates. In appearance, this disease is like a sunburn.

Appearance time: Throughout the summer.

Cause: Mushrooms Oomycetes from the Peronosporaceae family. The carrier is the wind, it can disperse the spores by 30-50 meters. The disease is provoked:

The last two factors especially often manifest themselves in closed ground (greenhouses and greenhouses).

Consequences: The plant quickly dies, while the spores of the fungus fall on the neighboring ones, affecting them.

Ways to fight: Particular attention is paid to prevention, avoiding excessive air humidity and poor lighting in growing areas, temperature extremes and irrigation with cold water. Treatment of seeds and soil before planting with a solution of potassium permanganate.

In case of damage to plants, apply:

1. Any copper-containing preparation (copper sulfate, Bordeaux mixture)
   

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2. Urea solution in water 0.1% (10 g per 10 liters of water)
   

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3. In some cases, the drug Ridomil Gold will help.

Symptoms: It is quite difficult to determine the disease immediately. In the early stages, the leaves wilt during the day and regenerate at night. After some time, a wet mold appears on the leaves, they turn yellow, dry out and partially fall off. Then the existing lashes dry and new ones are not formed.

Appearance time: Since the beginning of flowering. Peak from late May to late June.

Cause: Mold fungi of the Fusarium family.

Consequences: If you do not take action in the early stages (wilting and yellowing), the plant dies, which is why it is important to recognize it as early as possible. Often, by mistake, the daytime withered appearance of the leaves is mistaken for a lack of moisture. It is possible to cure Fusarium if measures were taken literally in the first days of the defeat.

Ways to fight: In case of damage, organophosphorus agents based on propamocarb should be used, for example, Previkur, Strobi, Topsin, etc. If the treatment does not help get rid of the disease, the affected plants are removed and burned.

As a preventive measure, it is necessary to carry out:

It is also recommended to observe crop rotation and regularly replace the soil in the beds.

Signs: The formation of light gray spots around the perimeter of the leaves. Then the spots cover the entire surface of the leaf plate and pass to the petioles. After some time, black dots form on them - the body of the fungus with spores.Rounded white-brown spots may appear on stems, shoots and fruits. Often affects greens and pickles.

Appearance time: Starting from the second decade of June.

Cause: The impact of two fungi-symbiotes from the Spheropsid and Didimeles families. Their spores can stay in the ground for several years. They are carried along with the soil and organic matter.

Consequences: Damaged fruits are unfit for consumption, the taste of their pulp becomes bitter. If the disease is running, the plant cannot be saved. Early stages are cured in 90% of cases.

Ways to fight: Treatment of affected plants can be carried out with various preparations. Can be used:

To prevent the disease, annual steaming of the soil is recommended as a preventive measure, as well as disinfection of the greenhouse with a 5% formalin solution. An effective means of prevention is the pesticide Trichoderma Veride, with which the plant is treated three times - during pre-planting, 15 days after planting and during flowering.

Symptoms: Weeping spots at the base of the stems, often with whitish borders. Over time, they begin to spread upward, then cotton or cobweb plaque and mucus form on the spots.

Appearance time: At any stage of development.

Cause: Sclerotia fungi, the spores of which hibernate in the ground or on plant debris. Sclerotinia attacks not only cucumbers, but also any other plants to which the wind carries spores. In addition, the appearance of the fungus is stimulated by temperature changes, watering with cold water, uncleaned plant residues from the last season and injury to plants.

Consequences: It spreads rapidly even at low temperatures (+15-16°C). The first spores form about a week after the appearance of weeping spots. They are carried by physical contact, and not only from the gardener, the peddler can be a field mouse and other animals (even ants and aphid colonies). If no action is taken, in about 10-15 days all cucumbers in the greenhouse or in the garden will be affected.

Ways to fight: At any stage, the ailment is effectively treated with Hom, Ordan, Topaz, etc. As a preventive measure, it is recommended to thoroughly disinfect the soil during its preparation and before planting, choose the right predecessors, monitor the temperature of the water for irrigation and humidity at the place of cultivation.

Symptoms: Thinning and drying of the stem. Damage to the root neck and roots with brown spots, which then darken. When cucumbers get sick, their leaves wither and die without any external cause. The stem darkens and becomes rotten, local necrosis is observed.

Appearance time: At any stage of development.

Cause: This is one of the most dangerous diseases of cucumbers that are of fungal origin. There may be several triggers. The main reason is too much watering. This leads to inhibition of root respiration, poor absorption of nutrients from the soil and vulnerability to various phytopathogens. In second place is the excessive salinity of the soil, due to excessive fertilizing.

Consequences: Any damage caused by root rot affects the aerial part of the plant. Infection in the early stages of plant life leads to the death of the crop and crop. If the infection occurred after the formation of the ovaries, the harvest will be poor.

Ways to fight: The fight against root rot does not give results, the plant will die anyway. Affected specimens are removed from the garden and destroyed immediately. To prevent infection, the following types of prevention are recommended:

Symptoms: It is quite simple to notice the appearance of the fungus: brown spots appear on any part of the plant, slippery when touched. The foliage will wilt slightly. After 2-3 days, the spots become covered with a gray coating.

Appearance time: At any stage of development.

Cause: Imperfect stage of the fungus Botrytis gray. Spores are carried by all possible means: wind, water (even through drops), insects, inventory. In addition, they survive in severe frosts. That is, the culture in the risk zone can be with any method of cultivation. The risk of infection increases with the previously described violations during care, as well as in rainy weather.

Consequences: Under favorable conditions, the fungus can quickly (within a week) spread to the entire plant. There is an inhibition of culture growth, the absence of new flowers and ovaries. When most of the leaves are affected, diseased plants dry out and die.

Ways to fight: At the active stage of the disease, specialized fungicides are used - Hom, Euparen multi, TMTD and others. Biological preparations will also be effective - Koniotirin, Trichocin, Glyocladin.

Symptoms: Most often, young (from 2-3 days old) fruits are affected. The harmful effect of the disease leads to the fact that the fruits change shape, and brown spots appear on their surface, which later turn black. Leaves are affected about half as often, but spots are more common on them.

Appearance time: from the third decade of June (the end of the growing season) to the end of August.

Cause: Asexual fungus pasalora fulva, found in the southern regions. Spread by any means. The main risk group is greenhouse varieties. The likelihood of damage increases with temperature fluctuations and high humidity. Too dense plantings also contribute to the spread of the disease. It is believed that a lack of phosphorus can provoke the disease.

Consequences: The damage is often local. There is a death of infected leaves and stems. The fruits are spoiled and should not be eaten.

Ways to fight: In the active phase of infection, the following methods of control are recommended:

As a preventive measure, it is recommended:

Symptoms: The appearance of red spots on the whole plant from 3 mm to 4 cm in diameter. Leaf blades become wrinkled. Later, small sores appear in place of the spots, then larger holes. Large ulcers form on the fruits, their development and growth slows down.

Appearance time: Plants are ill at any stage of development, the peak occurs in the second half of summer.

Cause: Ascomycete fungi spread by wind, rain or insects. Additional factors affecting infection are high humidity and unharvested plant residues from the previous year.

Consequences: With a significant damage to the leaves, the plant may die.In those specimens that have survived, growth and fruiting are significantly slowed down.

Ways to fight: Most modern varieties have good resistance to anthracnose. Sometimes it is enough to simply lower the humidity of the air and the disease will go away (at a humidity of less than 60%, the fungus does not develop at all). In some cases, the disease goes away if watering is stopped for a short time, which further stimulates the formation of female flowers.

In the treatment it is recommended to use the following drugs: Fitosporin, Previkur, Quadris. In the initial stages, Bordeaux liquid 1% is effective.

Prevention of anthracnose is the observance of crop rotation and the disinfection of soil and seed. It is also recommended to remove from the site and burn plant residues at the end of the season.

Symptoms: The appearance of convex dry spots of small size, formed at the bottom of the sheet. Then the spots increase, occupying the entire leaf surface.

Appearance time: At any stage of development

Cause: Fungi are plesiospores that live in the soil and on plant stems, where they feed on their sap.

Consequences: Leaves are predominantly affected. If no action is taken, the disease spreads to the entire bush and it dies.

Ways to fight: Use any copper-containing preparations. It is enough to treat the bush with copper sulfate or Bordeaux mixture.

Symptoms: Brown spots appear on the root collar and stem near the ground. Gradually, the spots grow larger and begin to rise up. Symptoms of the disease fit the description of the blackleg fungus found in peppers.

Cause: Mushrooms-basidiomycetes living in the soil at a depth of up to 25 cm. They begin to actively multiply already at + 4 ° C, acidity and soil moisture do not play a role for them. Can be found in any soil.

Consequences: All parts of the plant are affected except the flowers. The leaves are covered with brown spots, then the fruits turn brown. First of all, those parts of plants that are in contact with the soil are affected.

Ways to fight: Trichodermin, Radomil Gold or Quadris are used.

Preventive treatment, in addition to the standard recommendations for crop rotation and the need to maintain the correct temperature regime, involves the disinfection of the soil with Benomyl or Fundazol preparations. Before planting seeds, they should be treated with Baktofit.

Symptoms: Formation of brown oily spots on all parts of the plant. Every day the number of these spots is growing. With a decrease in humidity, the spots become covered with a crust and disappear.

Appearance time: The period of active vegetation, before flowering.

Cause: Caused by gram-negative bacteria. An increase in the number of bacteria is associated with frequent rains, after which periods of heat come. The plant's immunity simply does not have time to adapt to such a rhythm of weather changes. Seeds are also often contaminated with bacteria.

Consequences: If necrotic spots began to appear, the cucumber cannot be saved. Ultimately, only veins remain from the leaves and the plant dies.If measures are taken in time, about half of the crop still dies.

Ways to fight: As soon as the first symptoms appear, the greenhouse should be disinfected and aired regularly. The temperature inside should not exceed 25 ° C, and humidity - 70% (optimal - 60%). Plants are recommended to be treated with Phytoflavin - 300 or Gamair.

As a preventive measure, it is recommended to collect seeds only from unaffected plants, as well as disinfection of seed material with TMTD preparations. It is also recommended to use Phytoflavin - 300 and similar biological products for this purpose.

Symptoms: The appearance of yellow spots on the leaves, as in chlorosis. As the infection progresses, the leaves acquire an alternating color that resembles a mosaic. Young leaves shrivel.

Appearance time: The third decade of May - the second decade of August.

Cause: Cucumber mosaic virus (CMV). Most often found in greenhouses, in the open field is practically inactive.

Consequences: The whole plant is affected. Infected tissue areas do not perform their functions and the cucumber dies. Healthy plants, when in contact with infected ones, also get sick.

Ways to fight: This is one of the dangerous diseases of cucumbers. There is no treatment. It is possible to contain the spread of the disease if the plant is treated with a water-based Farmiod. But still, the complete removal and destruction of diseased plants is recommended in order to prevent infection of healthy cucumbers and other pumpkin crops (eggplants, zucchini).

Prevention implies compliance with agricultural technology, weed and pest control, regular crop rotation and disinfection of seeds and soil with Fundazol and Benomyl preparations.

Symptoms: The leaves wrinkle, and their veins become light, almost white. A characteristic "mosaic" is covered not with leaves, but with fruits.

Appearance time: At any stage of development.

Cause: Cucumber green mosaic virus CGMMV (speckled green mosaic virus is caused by the B3KMO virus). It spreads exclusively in greenhouses and hotbeds; no cases of infection have been recorded in open ground. Most often, the disease is activated with significant (more than 30 ° C) temperature increases. In addition, not only adult plants, but also seedlings can be infected.

Consequences: Similar to regular mosaic. The plant dies anyway.

Ways to fight: There is no cure. Affected plants must be removed from the garden in order to eliminate foci of infection and not destroy healthy specimens. The following preventive measures should be taken: