When and why do cucumber leaves turn yellow. Why the ovaries of cucumbers turn yellow and how to fix it Why cucumbers turn yellow in a greenhouse what to do

Almost every gardener is faced with a problem when cucumbers, leaves or ovaries turn yellow in a greenhouse. There are many reasons for this. What does this mean and what needs to be done to improve the situation, AiF.ru asked the experts.

“Most often leaves or ovaries get sick. If the fruit turns yellow, then most likely it is a lack of trace elements, nutrition. Perhaps not enough nitrogen. In this case, it is necessary to alternate root and foliar top dressing, ”says breeder Lyubov Chistyakova.

Biologist and agronomist Mikhail Vorobyov also believes that yellowing leaves and ovaries indicate a lack of nutrition. “Cucumbers turn yellow only in one case, when they are overripe. Then the skin becomes yellowish, and the pulp becomes completely tasteless, although edible. It happens that it is not the cucumbers themselves that turn yellow prematurely, but the ovaries. This is when the flower of the vegetable bloomed, a small fruit appeared, and then it turns yellow and disappears. This means that the plant lacks nutrients. Cucumbers are very sensitive to soil fertility. If the soil lacks nutrition, then the plant simply gets rid of extra cucumbers. They die at the earliest stage. This, of course, is embarrassing. If you notice such a disgrace, the plant must be fed. The best option is to fertilize the soil with horse manure, diluted in water 1:10, and let it brew for a couple of days, and preferably a week. If it is not there, then the most common fertilizer such as Nitrofaska, Azofoska or Gomel fertilizer, ”says Vorobyov.

Why do cucumber leaves turn yellow?

The problem when the leaves turn yellow also directly depends on the condition of the soil. Gardener and designer Olga Voronova explains this phenomenon with three reasons. If the castings are yellow and the veins are green, then there is not enough iron; if completely yellow, without veins - there is little calcium in the soil. Sudden changes in temperature in the greenhouse can also provoke yellowing.

“The greenhouse is such a stressful place in which any vegetables are not very comfortable. And here it is very important what material it is made of, since cucumbers react to any change in the weather and even to the change of day and night. If cucumbers have suffered some kind of climatic stress, then the plants lose nutrients, including iron, calcium. Processes slow down, the fruits temporarily stop absorbing nutrients from the soil, ”explains Voronova.

If this problem is detected, the leaves should be treated with epin and zircon, and the next day, the expert recommends spraying the leaves with a preparation containing calcium.

Every summer resident grows cucumbers in his garden; this is one of the most popular products that is used both fresh and harvested for the winter. Losing a crop of greens is a disaster. However, these crops often have such a problem as yellowing of the leaves. Let's figure out why the leaves on cucumbers turn yellow, what must be observed in agricultural technology and what kind of treatment for yellowing foliage is safe.

7 main reasons why cucumber leaves turn yellow, prevention and treatment

They can turn yellow in a variety of ways - along the edges, completely, either the upper leaves or the lower ones, and sometimes they change color and ovaries, and the fruits themselves. There are a lot of reasons for this, and almost all of them indicate that it is necessary to take measures to save the crop as quickly as possible. Different reasons - different actions, so it is necessary to thoroughly understand why cucumber leaves turn yellow.

7 problems due to which the leaves on cucumbers turn yellow:

1. Lack of sun. If the lower tops of the culture turn yellow, then this is normal. Most likely, they simply do not have enough light, which is natural, because the cucumber bush grows both in breadth and in height, and, naturally, the bottom row is deprived of the sun. In this case, you should simply cut off the lower leaves, this will not bring any harm to the crop.
2. Lack/excess moisture. Cucumber bushes are very sensitive to both excess and lack of water. Of course, this is a moisture-loving crop, so it needs watering at least 3 times a week, and quite plentiful, with deep wetting of the soil. And if the summer turned out to be hot and dry, then abundant irrigation is recommended to be carried out every day. Otherwise, the roots will begin to look for moisture on the surface and pull out their roots, which will naturally dry out. But gherkins do not like constant rain either - it can provoke decay of both roots and stems, as well as the appearance of powdery mildew.
3. Pests. Three pests are especially tangible to destroy the culture - these are the spider mite, whitefly and aphid. They feed on the juice of the plant, as a result of which the tops of the cucumber turn yellow. If a pest is found, it is necessary to immediately start a fight with it - you can use biological remedies (macrolofus bugs), but first use folk recipes.
4. Fungus. Yellowing of foliage in a culture can also provoke various fungal diseases. Most often this happens from a temperature difference - for example, it is hot during the day, and at night there is a sharp drop in temperature and the earth cools down greatly. During this period, you should be more careful about cucumber plantings. Most often, cucumbers are affected by peronosporosis (downy mildew) - when this fungus appears, the foliage is first covered with rusty spots, then the entire leaf is covered with such “rust”, after which it dies and falls off. This dangerous fungus not only easily overwinters in soil and plant debris, but also spreads with seeds. So buy seeds from trusted sources.
5. Nutrient deficiencies. The reason, frankly, is unlikely, but still there is a place to be. This problem is easily solved by top dressing, which must be made in order to make up for the lack of them, it is only important to correctly determine which elements of the culture are missing. So, for example, if the upper leaves turn yellow and fall off, then most likely there is a lack of copper, but if the edges turn yellow, then the cucumber additionally needs potassium and magnesium. And if the leaf is yellow, and its veins are green, then this indicates a lack of manganese or iron.
6. Hypothermia. Planted seedlings on an unheated bed in open ground often not only “freeze” and do not start growing, but react with yellowing of the tops. Often in this case, a yellow border appears on the leaves - the roots cannot absorb magnesium.
7. Old age. The most “non-terrible” reason for yellow leaves, since by this time a large percentage of the crop has already been harvested. Although here there are some options for how to prolong the fruiting of a cucumber.

We carry out the prevention of the appearance of yellow leaves in cucumber bushes

But, no matter what the cause is due to yellowing of the leaves on cucumbers, it is much easier to prevent than to treat the plant directly when it has already happened. Preventive measures should be included in the comprehensive care of the cucumber bed. What are they?

1. Compliance with crop rotation. This is the primary action in order to avoid fungal diseases of the cucumber. Firstly, cucumbers should not be planted on the same bed in a row for several years, and secondly, they should not be planted on a bed where zucchini and pumpkins previously grew.
2. Timely and sufficient watering. Cucumber cannot live without moisture. If it is not possible to carry out abundant watering several times a week, then you should take care of mulching the beds. First you need to saturate the soil with water, and then cover the cucumber beds with cut grass and plucked weeds - they will not only retain moisture longer, but also create a good microclimate and additional nutrition for the cucumber.
3. Top dressing of cucumber bushes with organic matter and ash infusion. It is necessary to water the cucumber beds with herbal infusion - it will provide the necessary nutrients. It is also good to use ash - pour it a little into the holes at the root, it will not only act as a source of potassium for the plant, but also protect against certain types of pests.
4. Preventive spraying of bushes using solutions and infusions prepared according to folk recipes. Here are some of them:

• A loaf of bread is soaked in a bucket of water, left overnight. In the morning it is necessary to crush it in water, add iodine (a small vial). One liter of this infusion is again diluted in a bucket of water and they are already watering and spraying cucumbers. This must be done 2 times a month, then until October the cucumbers will be green and vigorous.
• Iodine (about 30 drops), ordinary soap (about 20 g), milk (1 liter) are diluted in 10 liters of water. This solution is used to spray the tops for the first time - when the 3rd leaf appeared at the seedling, and then at regular intervals 4 times a month.
• For 10 liters of water, take 1 tablespoon of baking soda or biosoda. This solution should be treated with crops in the month of June, it will prevent possible fungal diseases.
• Onion peel is placed in 10 liters of water, brought to a boil, and then left for half a day under a lid. After that, the infusion is filtered through gauze, and a solution for spraying is prepared: the resulting infusion (2 parts) is diluted with water (8 parts). They moisten not only the upper, but also the underside of the leaves, it is also good to spill the ground with them.

What to do if the leaves turn yellow

Sometimes it also happens that preventive measures did not have time to be applied, or they did not fit, and the foliage of the plant still turns yellow. Should I cut off the leaves on cucumbers if yellow spots appear or a white bloom appears?

Until the stem is affected, and the plant restrains infection, then such leaves must be removed. But in no case do not twist them from the bush, and do not pull. Just carefully cut them off and take them to the compost bin. In addition, the following procedures apply:

1. Spraying with a solution using fermented milk products. For 10 liters of water, take 2 liters of whey, kefir.
2. Spraying with infusion using hay. To do this, hay is soaked in plain water, taking them in equal proportions, for 48 hours. It is enough to carry out the spraying procedure three times with an interval of 5-7 days. You can also add aerated compost tea here.
3. Top dressing from weed infusion and humus. Both of these natural fertilizers are applied under the roots. The action of root top dressing can be enhanced by foliar - sprayed with growth stimulants (Zircon, Epin-Extra, Novosil, HB-101) mixed with humates or EMCs.
4. Biological preparations, such as trichodermin, are used in the fight against fungi and bacteria. They are safe for animals and humans. But it is extremely important to observe the recommended proportions, otherwise, instead of enhancing the growth of the plant, you will get its oppression.

Finally, it would be useful to recall that Zelentsy pour and sing very quickly, so it is dangerous to use chemistry for treating plants. And folk remedies and proper agricultural technology will help you save the crop if you notice the yellowing of cucumber foliage in time. We hope you have now figured out why the leaves on cucumbers turn yellow, and what needs to be done to protect plants.

Why cucumbers turn yellow in a greenhouse is explained by five factors of violation during care:

nutritional deficiency

Rational nutrition of the soil at the time of digging in spring and autumn will enrich it with minerals. It is enough to add rotted manure, ash, superphosphates and fertilizers rich in potassium. Only the lack of these minerals leads to the fact that at first they brighten, then yellowing appears. This deficiency also affects the fruits themselves - they begin to curl.

Lack of heat

Low night temperatures are one of the primary reasons why cucumbers turn yellow in a greenhouse. Cucumbers are heat-loving plants that react very sharply to temperature changes. This happens especially often in central Russia, when the last frosts attack at night. To prevent this from happening, it is necessary to insulate both the greenhouse itself, covering it with a film, and the plant itself, placing containers with water next to the seedlings. The water must be hot enough, because the temperature for the favorable growth of cucumbers must be at least + 22 ° C.

Lack of water and low humidity

The plant gives a signal that it lacks moisture by twisting and yellowing leaves. With insufficient watering, the roots take moisture from the stem and leaves, so the cucumbers turn yellow in the greenhouse. In this case, it must be remembered that for active fruiting, watering twice a week is needed. For one plant, 25 liters will be enough. warm water, and it will delight you with tasty and juicy fruits.

Excess ovaries

To form a whip, it is necessary to pinch in a timely manner and remove the ovaries if there are more than 20 of them on one fruiting plant. An excess of ovaries will also be the reason when cucumbers turn yellow and have an irregular shape in the greenhouse.

Pests and diseases

Powdery mildew can appear after watering with cold water. The leaves begin to lighten and fade, spraying with a manganese solution and a mullein solution will serve as an ambulance.

In case of damage by root dust, the soil must be fertilized with chalk, ash and crushed coal. Plants whose roots are already affected by the disease must be removed along with the affected soil to avoid further spread to healthy roots.

The spider mite primarily affects the inside, yellowing of the area occurs, and then the entire leaf. A warm environment in a greenhouse is a favorable atmosphere for tick reproduction, therefore, in order to prevent further damage to plants, they must be disinfected with a special agent "Akarin" or "Fitoverm".

One of the most dangerous enemies of the cucumber is the greenhouse whitefly, which can feed on the juice of leaves and stems. Frequent weeding will partially eliminate this problem, due to which the cucumbers in the greenhouse also turn yellow, because the whitefly passes from the weeds to the fruit-bearing plant. When ventilating the greenhouse, the opening should be closed as much as possible with a breathable mesh. Spraying with water should be done as often as possible and do not forget to loosen the soil, apply fertilizer in the form of rotted sawdust, peat and humus.

The reason for the appearance of aphids on the plant is the same as in the previous case - the presence of weeds. In addition to thorough weeding and loosening the soil of the greenhouse, it is regularly necessary to spray the lashes with soapy water and tobacco infusion.

In order to avoid questions about why cucumbers turn yellow in a greenhouse, it is necessary to take into account all of the above factors that affect the quality and fertility of this plant.