Diseases of the leaves of cucumbers: descriptions with photos, treatment
There is hardly any other vegetable in the world that could compete with cucumbers in popularity. But, unfortunately, people's love is not a panacea for all diseases, viruses or fungi. It is important to detect the problem in time, and large tall leaves of cucumbers will serve as an excellent indicator. We tell!
Pimples and tubercles on the leaves
Irregularities, tubercles and swelling on the surface of the leaves of cucumbers often indicate the presence of pests. Insects lay eggs or leave their waste products. But there are other reasons!
- Odema or dropsy - these are small tubercles on the leaves of garden crops that appear due to stress or improper conditions of detention;
- Pimples on the leaves of cucumbers appear due to hypothermia or after early planting in warm greenhouse soil;
- When the whitefly attacks the cucumbers, it leaves behind wart growths;
- Small formations on the front side of the leaves remain when it hides on the reverse side and makes aphid masonry.
Leaves turn yellow and dry
It is not surprising if the leaves begin to turn yellow or dry, because this is a natural reaction of the plant. The reasons can be almost anything - from improper care to an incurable virus, so pay attention to the accompanying symptoms.
- Due to lack of moisture, the leaves of the cucumbers turn yellow and dry, but if the seedlings are constantly transfused, they will begin to turn yellow and rot;
- If there is too much sun, this is fraught with burns on the leaves. And when too little - the process of photosynthesis is disrupted and cucumbers lose their green pigment;
- Yellow spots and stripes that are woven into a mosaic pattern - a symptom of the incurable mosaic virus;
- Peronosporosis leaves pale yellow spots on the leaves, which gradually become larger and darker.
Brown spots on the leaves of cucumbers
Chaotic spots of all shades of red and brown most often appear due to fungal diseases. There are a lot of them, but the treatment principle is similar - remove the source of infection and treat everything around with fungicides.
- Dark gray-brown spots spread on the leaves and stems when affected by ascochitosis. Gum secretions may remain in their places;
- Fusarium affects the root system and the whole plant as a whole, so that brown spots on the leaves of cucumbers can be its symptom;
- If brown spots look oily - this is bacteriosis, and it spreads very rapidly;
- Cladosporiosis is an olive spot, which is expressed as dark spots with an olive tint;
- The spots of bacterial spotting appear soft and as if wet. In the future, they may turn into open sores.
Cucumbers turn black leaves
If the leaves have already begun to blacken - this indicates a more advanced stage of the disease. In the worst case, full-fledged necrotic foci appear on the cucumbers.
- The leaves turn black, and the stems become rotten when the root rot destroys the cucumbers. It is difficult to notice in the early stages and therefore very difficult to cure;
- Due to bacterial cancer, tumors, ulcers and black spots form throughout the plant;
- Less often, cucumbers blacken due to late blight, which also affects the whole seedlings.
White coating on the leaves of cucumbers
Among the typical manifestations of fungal diseases is a white coating on the leaves, regardless of localization and shade. Sometimes upon closer inspection, it turns out to be a shallow and plentiful web, but there is a solution too.
- A whitish web on the leaves and between them leaves a spider mite that lives on almost all plants;
- A white coating on the leaves of cucumbers on warm wet days remains when affected by powdery mildew;
- If white leaves resembling cotton wool form on the leaves, this is sclerotinia. Gradually, the cucumbers are completely covered with a coating.
Pale and light leaves
Leaves change color along the entire plate due to chlorosis, which can have a lot of reasons. This is affected by non-compliance with agricultural technology, weak immunity of cucumbers or concomitant diseases.
- Due to the lack of fertilizers or individual trace elements, the seedlings of cucumbers fade and turn yellow. Most often it is nitrogen, calcium, iron or boron, but we recommend the use of balanced complexes;
- Young leaves immediately grow weak if conditions of detention or soil are not suitable for them;
- Home seedlings brighten when there is not enough sun, so it is better to rearrange it to the window or balcony;
- Some types of mosaics leave not yellow, but white chaotic spots. For example, alfalfa.
Cucumber leaves twist
Even large and rather weighty cucumber leaves can curl or deform. Basically, the problem is pests or viruses that infect the plant at the cellular level.
- The leaves of the cucumbers curl up and wither away if they do not have enough space. The beds cannot be too thick, because they should not be crowded, and they should be purged;
- Verticillin wilting may be another reason why cucumber leaves curl and fade without other visible problems.