Cucumbers grown in the country fragrant and healthy. They differ significantly in taste from vegetables bought in the supermarket. But to grow healthy cucumbers is not so easy, the plant is prone to many diseases. Often, gardeners face the problem that cucumber seedlings turn yellow leaves.
The problem begins when the second true sheet appears. The second leaves grow, and the first begin to change the pigmentation. And the case may be, not at all in the substrate in which the seedlings are planted. So why are cucumbers sick at an early stage of development?
Why do yellow leaves of cucumbers?
The causes of leaf burning can be several, the main ones include:
- Lack of potassium, nitrogen, sulfur, calcium, manganese in the soil. An imbalance of nitrogen and potassium, the correct ratio of 1 to 2 elements. An excess of nitrogen affects the pigmentation of the foliage and can lead to ammonia poisoning.
- Insufficient watering affects the yellowing of seedlings as well as strong waterlogging.
- Temperature drops. If the temperature in the root zone drops below 17 degrees, the plant is not able to receive micro and macro elements from the soil. At this temperature, even if all the beneficial elements are in the soil, they do not enter the stem.
- Toxin poisoning. Some farmers put seedlings on foam plates. Yellowing can be caused by poisoning by chemical compounds that are released by the insulating layer, since the roots of the plant are in contact with it. Fertilizer, falling on the foam, can lead to the release of harmful substances, which is dangerous not only for seedlings, but also for the harvest.
- Seedlings can be closely in the peat cup, so many gardeners immediately sow the seeds in the ground. Roots need space and good nutrition. Yellowing leaves may indicate that it is time to replant the plant.
- Lack of light.
Yellow leaves of cucumbers: what to do?
- Balance the dose of fertilizer, do not exceed the ammonia content in the solution. With a lack of nitrogen, you need to fertilize the plant with Vermistim or Azogran.
- If you use a foam substrate, then perepilat it on top of the film.
- If the seedlings grow on the balcony, then you can use the backlight.
- Do not forget to follow the microclimate. Cucumbers love water, so do not skimp on watering. However, remember that the plant should be watered only with warm water, outdoor temperature. If you water the plant with cold water disease can not be avoided.
- At the seedling stage, the plant is especially sensitive to potassium deficiency; if you do not follow the development, cucumbers will grow in an irregular shape. The best solution for cucumber seedlings is a nutritional solution based on complex fertilizers. For example, Kemira Hydro.
But the leaves of cucumbers turn yellow around the edges not only in seedlings, but also in adult plants. This may be due to the fact that the plant is fully matured. If there is a high temperature in the summer, and cucumbers are poorly watered, then the yellowing process is natural. Both in seedlings and in adult plants, the change in pigmentation is associated with a lack of beneficial substances. Yellowing of the leaves is due to frost. Fungal diseases of the plant and parasites can also affect the appearance of painful symptoms.
Cucumbers turn yellow leaves: diseases and parasites
Cucumber leaves turn yellow around the edgesdue to the following fungal diseases and parasites.
- Mealy dew. First, the leaves are covered with white bloom, and then the disease leads to yellowing of the foliage. Mealy dew is a fungus, it slows down plant growth. It is better to use varieties resistant to the disease. As soon as you notice white bloom, use the preparations "Caratan" or "Bayleton". Processing is carried out in dry weather in the evening. It is powdery mildew that is the most common disease of cucumbers, which leads to yellowing of leaves and damage to the ovary. It is most dangerous to get powdery mildew at the fruiting stage. Increases the degree of damage rainy weather.
- Root rot.The cause of the disease can be differences in day and night temperatures, watering plants with cold water. Affects weak seedlings. Prevention is the treatment of roots "Previkur." Processing takes place in two stages with an interval of 2 weeks.
- Fusarium - fungal disease, fungal spores block the capillaries, and beneficial substances do not flow to the plant. Toxins affect the plant at any stage of development, which leads to its death. To save the next crop of cucumbers from Fusarium, change the soil and pick up other varieties.
- Downy mildew.The leaves infected with fungus turn yellow and curl. Since the disease affects cucumbers since July, the treatment of the plant must begin from the end of June. Bordeaux mixture, "Kuproksat" - the first part of preventive and therapeutic measures, the use of "Acrobat", the drug "Bravo" - the second stage of the treatment of pernoporoz. It is best to choose cucumber varieties resistant to the disease.
- Aphids melons sucks all the juice from the seedlings, so the cucumbers on the windowsill yellow leaves.
- Tick spider web.The tick parasitizes the leaves and fruits of the plant and feeds on the plant sap.
If you are faced with the problem of yellowing of leaves in seedlings, try to create optimal conditions for cucumbers. Balance the amount of trace elements, monitor the ratio of potassium and nitrogen, add manganese, calcium and sulfur, as fertilizer. Do not overdry, but do not overwet the soil. Conduct prophylactic treatment for parasites and fungal diseases. Subject to all the above conditions, you will certainly collect a quality crop of cucumbers.