Only after establishing the true cause of the white spots can you begin to eliminate the problem. Illiterate actions can lead to the death of plants.
Causes of white spots
Cucumbers are one of the most popular vegetable crops. Many vegetable growers want to see it in their gardens, even though there are some difficulties associated with growing it. Cucumbers are very sensitive to unfavorable growing conditions: improper temperature conditions, lack of light, insufficient watering, poor ventilation. Plants react to errors of gardeners with various changes: wilting, twisting of leaf plates, changing their color.
One of the biggest problems with growing cucumbers is the appearance of white spots on the leaves.
Various factors can cause this problem, but most often it is fungal disease powdery mildew... The virus infects the entire leaf plate, and it looks like it was sprinkled with flour.
In addition, the disease harms young shoots and stems. The affected bush withers, dries and if you do not take action quickly, the plant will die.
Powdery mildew develops mainly in greenhouses. Especially if the room has too high humidity from frequent and heavy watering and poor ventilation. And if the temperature regime is still poorly observed and the air temperature is low in the greenhouse, then these are the most favorable conditions for the development of powdery mildew.
Affected leaves completely change their color, shrivel and die off. The stems lag far behind in development and also disappear over time. If fruits appear on infected lashes, then they ripen ahead of time. They are distinguished by underdevelopment, bad taste and low sugar content.
Gardeners are also aware of other diseases, as a result of which the leaves of cucumbers turn white.
Such an unpleasant phenomenon can cause white mosaic - a fungal-viral disease that covers the leaf plate with spots in the form of white stars. With a strong infection, the leaves of the plant can turn completely white.
The affected bush ceases to bear fruit or gives a meager yield of small fruits that have a bumpy surface and are painted with white-yellow stripes.
White spots can cause infection ascochitis.
The affected part of the sheet dries and cracks. With the development of the disease, the white spots turn brown, the plant turns black and dries.
White flocculent patches can appear on cucumber leaves, lower stems, fruits and roots as a result of infection white rot.
The affected areas become soft, the plant withers and dies. When in contact with diseased areas of the plant, the fruits are also infected.
The yield on such a plant drops sharply.
Methods to deal with the problem
After it became clear why the leaves of the cucumbers in the greenhouse were covered with white spots, you can start treating the plants.
To combat powdery mildew, mullein infusion is used.
To prepare it, you need to mix 1 kg of manure with 3 liters of water. The mixture should be infused for 3 days. Then strain it, add 3 liters of clean water and spray the diseased plant with the resulting solution.
Plants affected by white mosaic, must be immediately removed from the garden.
All garden tools used for working in the greenhouse should be disinfected with a solution of potassium permanganate.
Next year, before planting seedlings, you need to treat the soil with disinfectants.
When signs of white rot disease appear on the plant it is necessary to remove the affected leaves, and sprinkle the stems with fresh soil to form additional roots.
Plants affected by ascochitosis, must be sprayed with Bordeaux liquid.
In case of severe infection, it is necessary to remove the diseased bushes from the garden and burn it.
To prevent the appearance of diseases and get a good harvest of cucumbers, you need to strictly adhere to certain rules for growing this crop.
For normal growth, the bush needs good ventilation. In the process of growth, it is better to remove all the lower leaves so that fresh air can freely penetrate to the lower part of the bush.
Closely monitor the observance of the temperature regime. Large temperature changes have a detrimental effect on plants and their fruits. There must be good ventilation in the greenhouse.
Only lukewarm water should be used for irrigation. It is better to hold these events in the morning or evening. Do not get too carried away with various dressings. Cucumbers do not tolerate oversaturation of nutrients. Throughout the growing season, preventive spraying should be carried out, for example, with a urea solution. This will strengthen the plants and prevent disease.
