by Cucumbers grow well in a warm and humid climate. But in the middle zone it is not always possible to create ideal conditions for growing this popular crop. One of the problems that can be encountered is yellowing of cucumber leaves.
Cucumber leaves can turn yellow not only at the end of the season, which is associated with the natural aging of the plant, but also at the beginning of the growing season, especially if the cucumbers were grown using seedlings. After transplanting seedlings into the soil, the plants experience stress; at first, their strength goes to rooting, and they cannot fully absorb nutrients from the soil. But after rooting, cucumbers, as a rule, quickly grow if favorable conditions are created for them.
Stress after transplantation is only one reason for yellowing cucumber leaves, but there are other factors that can provoke this.
Irregular watering
Cucumbers are moisture-loving plants that react very quickly to changes in soil and air humidity. Therefore, this crop should be watered regularly, as the soil dries out, and try to maintain air humidity in the greenhouse or under a film cover within 80-90%. The soil in the root zone should always be moderately moist, especially during the fruiting period. If there is a lack of moisture, not only can the cucumber leaves turn yellow, but the ovaries can also fall off. In addition, it is important to water cucumbers with settled water, the temperature of which is on average 23-25 ° C.
What to do
Water the cucumbers generously, moistening the soil to a depth of at least 20 cm. And to maintain constant soil moisture, it is advisable to mulch the bed with hay, straw, rotted sawdust or other material. Mulching will help to facilitate the care of the plantings and reduce the frequency of watering, weeding and avoid loosening the soil, which can damage the root system of cucumbers.
Lack of food
Cucumbers are very demanding of soil fertility. Since they develop intensively in a short period of time and consume a large amount of nutrients, you need to take care of regular fertilizing.
Most often, the lower leaves turn yellow or become light green, thin due to a lack of nitrogen. If yellowing appears along the edges of the leaves, then the cause is potassium deficiency. With a lack of magnesium, the leaves turn yellow between the veins. With prolonged starvation, yellowing begins to appear first on the lower leaves as on older ones.
What to do
When preparing a bed for sowing cucumbers, add organic fertilizers: humus, compost, vermicompost. During the growing season, water the cucumbers with herbal infusion (nettle, dandelion and other weeds), infusion of bird droppings (diluted with water in a ratio of 1:10), add complex mineral fertilizers (Kristalon Ogurechny, Rodnichok, Agricola for cucumbers, zucchini, squash, etc.).
It is not recommended to add excessive amounts of nitrogen to a bed of cucumbers, especially if there is a lack of phosphorus. This causes increased growth of leaves and shoots, while flowering and fruiting are delayed.
Solar burns
Cucumbers do not like to grow in the sun, and young, weak plants are especially sensitive to bright sunlight. If you have transplanted seedlings from a greenhouse into open ground, shade the plantings for the first few days, otherwise light yellow or whitish areas may appear on the leaves – sunburn. They also appear as a result of improper watering, if water gets on the leaves in sunny weather. Therefore, try to water cucumbers in the morning or evening hours.
What to do
Install a frame of arcs over the bed and cover the plantings with spunbond. If the nights are cold, you will need a denser covering material, and if it is hot, you can use thin spunbond to lightly shade the bed and reduce moisture evaporation. This will also prevent the cucumbers from becoming bitter.
Root rot
If the soil is over-moistened, especially in cold weather, cucumbers may suffer from root rot. It is caused by pathogenic fungi found in the soil. When favorable conditions are created (high humidity, temperature fluctuations, poor air circulation, dense and acidic soil), they begin to multiply quickly and damage the roots of plants.
What to do
Reduce watering in cold weather. Do not use cold water, which is lower than the soil temperature, to water cucumbers.
If you notice that the cucumber leaves are turning yellow, wilting, and the plant is dying, cut off the above-ground part, remove the lower leaves and place the cutting in water.
After some time (usually 7-10 days) new roots will form on it, and it can be planted in the ground again. To prevent re-infection, pour the soil with a biofungicide solution. For this, you can use Fitosporin-M or Trichocin.
Many gardeners are afraid to propagate cucumbers by cuttings, believing that this method of propagation is not suitable for this crop. But in vain: roots quickly grow on cucumber stems, and in this way you can not only save a dying plant, but also increase the amount of planting material.
Thickened plantings
If you plant cucumbers densely and do not shape the plants, then very quickly all the stems will intertwine, shade each other, and some leaves will begin to turn yellow due to lack of nutrition and light. The shoots will become thin, weak, and fruits will not be able to form on them. In addition, dense plantings will be poorly ventilated, which can lead to the emergence of various diseases. Although cucumbers can bear fruit even in low light, it is advisable to plant no more than four cucumbers per 1 sq. m of bed so that the plants can develop fully.
What to do
Pinch off side shoots, tie the vines to the trellis. First of all, it is worth removing weak shoots that thicken the bush, as well as those that do not have ovaries. And if you are afraid of damaging the bush, you can limit yourself to pinching the growth points of the lower stepsons, and leave stronger shoots in the upper part of the bush. Hybrids with a cluster ovary are recommended to be grown in one stem, since a large number of fruits are formed on it.
When growing cucumbers, as well as other garden crops, try not only to follow the basic rules of agricultural technology, but also to protect the plantings from diseases and pests. Then your cucumber beds will long delight you with a harvest and a healthy appearance of plants.
