White spots appeared on the leaves of cucumbers: why and what to do

Many gardeners yearly dream of getting a bountiful harvest of vegetables, but white spots on the leaves of cucumbers threaten the death of most plants. The presence of plaque indicates the appearance of diseases or pests on plants. The sooner the problem is identified and treated, the more likely it is to save the crop.

Specialists identify a number of diseases that are characterized by a white coating on the leaves of plants. The most common disease in summer cottages is powdery mildew, mosaic. On the leaves of cucumbers, white spots indicate a spider mite infection.

Powdery mildew

White coating on the leaves of cucumbers indicates infection of the plant with powdery mildew. It appears first at the edges of the leaf plate, gradually covering the entire area. Then the disease spreads to shoots and stems. A characteristic symptom is not only spots, but also a fluffy coating of light color.

Infection of plants starts from the top of the front plate. The disease can appear on bushes located closer to open windows. In the absence of a fight against the disease, the bush begins to wither, the crop is completely lost.

Reasons for appearance

If we talk about what causes powdery mildew, then pay attention to the conditions for keeping cucumbers. The prerequisites for the appearance of a disease in a greenhouse are:

• coolness and high humidity;
• increased planting density;
• increased nitrogen content in the soil;
• drying the soil followed by overflowing plants;
• excessive watering of plants;

Methods of struggle

Powdery mildew responds well to treatment. When the first signs of plant damage appear, you need to start fighting it.

To cure powdery mildew you need:

• stop all spraying;
• avoid fertilization;
• improve lighting in the greenhouse;
• thin out plantings;
• remove affected, old or weakened leaves;
• cut flower stalks.

Directly with stains, treatment of plants with antiseptic compounds allows you to fight. Chemical antifungals and folk remedies are used in garden plots.

1. Topaz. Antiviral drug with the active substance - penconazole. To prepare the solution, 1 ampoule per 10 liters of water is used. Plants are treated every two weeks until plaque stops appearing.
2. Emulsion Tilt CE. An effective drug based on propiconazole. It is dangerous for bees and fish. Suitable for fighting plaque and disease spores. Most effective at elevated temperatures.

In addition to Topaz and Emulsion, Sulfaride, Bayleton, Skor, Vitaros showed high efficiency. In the early stages, Bordeaux liquid and oxychloride are suitable for the fight. Soap-soda solution helps to remove powdery mildew with folk remedies. What to do and what methods of struggle to choose directly depends on the degree of damage and the spread of the disease.

White Mosaic

White or cucumber mosaic is a viral disease. Cucumbers, tomatoes, cabbage and other vegetable crops are susceptible to it. The main development of the disease occurs in the living cells of the plant. But the virus can be transmitted through a dry leaf. It persists in soil and inventory for a long time.

Features of manifestation

Cucumber mosaic, falling on the leaf of a he althy plant, leads to the destruction of chlorophylls. As a result, the level of carbohydrates in the plant decreases. The characteristic symptoms of white mosaic are light spots, which at first have fuzzy contours. Their localization occurs in the veinlet area.

Gradually the spots increase in size. Cucumber leaves turn completely white or yellow. Plant growth is suppressed, yield is reduced.

White mosaic is a greenhouse problem. The reasons for its appearance include:

• high planting density;
• increased room temperature;
• Sharp fluctuations in air temperature.

The disease often appears on cucumber seedlings that have just been transplanted into the ground. Young leaves and shoots of the plant are also affected.

Methods of struggle

If a lot of white spots and signs of mosaic damage appear on the leaves of cucumbers, then it is necessary to start fighting the virus as soon as possible. It should be understood that the treatment of plants is ineffective.

To cure the disease and prevent its occurrence, a number of rules should be observed.

1. Normalization of the temperature regime. In the room where the cucumbers are located, the temperature should be reduced and its drops should be excluded. Temperatures below 30 degrees are optimal.
2. Removal of affected leaves. It is necessary to remove all leaves on which white spots appear. In some cases, whole cucumbers are removed.
3. Inventory processing. All inventory that came into contact with cucumbers must be treated with boiling water, antiseptic solution or alcohol.
4. Reducing planting density. Cucumbers should be thinned out and given more air and space.

Prevention of the appearance of white spots on cucumbers is the use of mosaic-resistant varieties, regular weeding of the greenhouse and cleaning the premises, using only high-quality seeds for sowing seedlings.

Spider mite

Cucumbers grown outdoors are susceptible to spider mite infestation. It feeds on the sap of plants and leads to the drying of the green mass. Cucumbers grow small, deformed. If you do not treat the plants from the parasite in time, you can lose the crop completely.

Features of manifestation

The presence of a number of signs indicates the appearance of a spider mite on cucumbers:

• light dots on the leaf plate;
• thin cobweb on the back of the sheet;
• plant growth retardation;
• yellowing of the green mass.

Methods of struggle

Emerging disease is easier to prevent than to deal with it when it hit mature plants. As prevention methods before planting cucumbers, they carry out:

• digging the soil;
• weed removal;
• alternating crops.

If the leaf on the cucumbers turns white and there are signs of a tick, then it is necessary to process the plants and carry out preventive work. To do this, all dry and infected leaves are removed and burned. Humidity in the greenhouse is increased to 70-80%. The tick cannot tolerate humidity above 60%.

Cure the disease completely allows disinfection with chemicals. Showed high efficiency in the fight against ticks:

• Actellik;
• Appolo;
• Neoron;
• Karbofos;
• Sunmite;
• Fitoverm.

Most drugs have a wide spectrum of action and belong to the budget category. If you are fighting diseases with folk methods, then the following are considered effective:

• soap solution;
• garlic;
• alcohol solution;
• onion solution;
• Caucasian hogweed decoction.

The fight against the tick should begin as soon as the first signs of damage are detected. If its spread is not prevented in the initial stages, all plants will be covered with white dots.

Ascochitosis

White spots on cucumbers in a greenhouse may result from ascochyta infection. The disease affects weakened bushes. The fungus is soil-borne or carried in organic debris.

Features of manifestation

The disease appears as white or brown spots along the edges of the plant. Gradually, the entire leaf becomes covered with spots. The affected area dries up. As a result of a fungal infection, the cucumber stops growing. Copper exudate appears on the stems.

Fruits are mutating. They are covered with black dots, resemble boiled vegetables, and are completely unfit for human consumption. The disease is most active during the fruiting period.

If you figure out why ascochitosis appears on the leaves of cucumbers, then gardeners identify a number of reasons:

• weak plants;
• high indoor humidity;
• presence of fungus in the soil;
• non-observance of crop rotation in the garden plot.

Methods of struggle

White plaque on cucumbers can be prevented if you follow the rules for the fight and prevention of ascochitosis.

1. Cultural turnover. It is necessary to regularly change the planting sites of crops on the ridges.
2. Mulching. So that the leaves do not become stained, the surface of the soil after planting is covered with mulch or plastic wrap.
3. Use of resistant varieties. To prevent the development of ascochitosis allows the use of varieties resistant to the fungus.
4. Sowing on the plot of sanitary crops. Seeding green manure (rye, oats) allows for a comprehensive sanitary treatment of the soil.
5. Antiseptic treatment. If the leaves are stained, then it is necessary to remove the affected areas and treat the plants with antiseptic solutions. Spraying with Bordeaux liquid or smearing the stems with copper-chalk powder showed high efficiency.

Most often, there are spots on the leaves of cucumbers in the greenhouse. This is due to the increased temperature and humidity in the room. When choosing how to treat, it is necessary to rely not only on the experience of gardeners, but also on the type of disease that affected the plants.Also prevent infection allows timely prevention and competent care of plantings.

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