Only after establishing the true cause of white spots, you can begin to eliminate the problem. Illiterate actions can cause the death of plants.
Causes of white spots
Cucumbers are one of the most popular vegetable crops. Many vegetable growers want to see her in their gardens, even despite some of the difficulties associated with growing her. Cucumbers are very sensitive to adverse growing conditions: incorrect temperature conditions, lack of light, insufficient watering, poor ventilation. Plants react to the mistakes of gardeners with various changes: withering, twisting of leaf plates, changing their color.
One of the biggest problems when growing cucumbers is the appearance of white spots on the leaves.
This problem can be caused by various factors, 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 measures are not taken quickly, the plant will die.
Mostly powdery mildew develops in greenhouses. Especially if the room has too high humidity from frequent and abundant watering and poor ventilation. And if the temperature regime is still poorly observed and the air temperature in the greenhouse is low, then these are the most favorable conditions for the development of powdery mildew.
Affected leaves completely change their color, wrinkle and die. The stems are far behind in development and also fall off over time. If fruits appear on infected lashes, 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 may turn completely white.
The affected bush ceases to bear fruit or gives a meager harvest of small fruits that have a bumpy surface and are painted with white-yellow stripes.
The appearance of white spots can cause infection ascochitis.
The affected part of the leaf dries and cracks. With the development of the disease, white spots turn brown, the plant turns black and dries.
A white, flaky coating may appear on cucumber leaves, undersides of stems, fruits, and roots as a result of infection. white rot.
The areas affected by the disease become soft, the plant withers and dies. In contact with diseased areas of the plant, the fruits become infected.
The yield on such a plant drops sharply.
Methods for dealing with the problem
After it became clear why the leaves of the cucumbers in the greenhouse were covered with white spots, you can begin to treat 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 must 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 ascochyta, must be sprayed with Bordeaux mixture.
With a strong infection, it is necessary to remove diseased bushes from the garden and burn them.
To prevent the occurrence 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 lower leaves so that fresh air freely penetrates to the bottom of the bush.
Closely monitor compliance with the temperature regime. Large temperature fluctuations have a detrimental effect on plants and their fruits. The greenhouse must have good ventilation.
For irrigation, use only warm water. It is better to carry out these activities in the morning or evening hours. Do not get too carried away with various dressings. Cucumbers do not tolerate nutrient overload. During the entire growing season, preventive spraying should be carried out, for example, with a solution of urea. This will strengthen the plants and prevent diseases.