Only after establishing the true cause of the white spots can we 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 it in their gardens, even despite some difficulties associated with its cultivation. Cucumbers react very sensitively to unfavorable growing conditions: incorrect temperature conditions, lack of light, insufficient watering, poor ventilation. Plants react to gardeners’ mistakes with various changes: withering, curling 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 blade, and it looks as if it has been sprinkled with flour.
In addition, the disease harms young shoots and stems. The affected bush withers, dries out, and if action is not taken quickly, the plant will die.
Powdery mildew mainly develops in greenhouses. Especially if the humidity in the room is too high from frequent and abundant watering and poor ventilation.And if the temperature regime is poorly maintained 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, shrink and die. The stems lag far behind in development and also fall off over time. If fruits appear on infected vines, they ripen ahead of time. They are distinguished by underdevelopment, poor taste and low sugar content.
Gardeners are also aware of other diseases that cause cucumber leaves to turn white.
This unpleasant phenomenon can cause white mosaic - a fungal-viral disease that covers the leaf blade with spots in the form of white stars. If the infection is severe, the leaves of the plant may turn completely white.
The affected bush stops bearing fruit or produces a meager harvest of small fruits that have a bumpy surface and are colored with white-yellow stripes.
The appearance of white spots can cause infection ascochyta blight.
The affected part of the leaf dries and cracks. As the disease progresses, the white spots turn brown, the plant turns black and dries.
A white flaky coating may appear on cucumber leaves, lower stems, fruits and roots as a result of infection white rot.
The areas affected by the disease become soft, the plant withers and dies. When the plant comes into contact with diseased areas, the fruits become infected.
The yield of such a plant drops sharply.
Methods to combat the problem
Once it has become clear why the leaves of the cucumbers in the greenhouse are 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 should infuse 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 removed from the garden immediately.
All garden tools used for work 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 blight, it is necessary to spray with Bordeaux mixture.
In case of severe infection, it is necessary to remove the diseased bushes from the garden bed 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. During the growth process, it is better to remove all lower leaves so that fresh air can freely penetrate to the lower part of the bush.
Carefully monitor compliance with the temperature regime. Large temperature changes have a detrimental effect on plants and their fruits. The greenhouse room must have good ventilation.
Only warm water should be used for irrigation. It is better to carry out these events in the morning or evening. Don't get too carried away with various fertilizers. Cucumbers do not tolerate oversaturation with nutrients.During the entire growing season, preventive spraying should be carried out, for example, with a urea solution. This will strengthen the plants and prevent diseases.
