How to protect seedlings from hares in winter. Methods for protecting fruit trees from hares. Interesting facts about the main pest of the winter garden

It becomes especially offensive if just yesterday the vines of cucumbers looked great, quickly grew, fruits formed en masse on them, and the next day the cucumbers look like boiled ones, their leaves hang lifelessly and the ovaries fall off. Most often, the reason that green cucumbers wither is - in the wrong microclimate: at excessively high temperatures, cucumber seedlings not only wither, but also lose their ability to pollinate. After all, growing cucumbers in a greenhouse requires the right choice varieties and more careful care than is required for cucumber varieties for open ground. In other cases, it may be due to numerous diseases caused by bacteria, viruses and other infections, much like in humans.

Cucumber diseases

The most dangerous and common diseases of cucumbers are:

downy mildew; common mosaic; cladosporiosis.

Pests of cucumbers

In other cases, cucumber seedlings may wither when attacked by pests that suck the juices from the leaves or gnaw the roots. There are also many of these pests, but the most common of them include:

greenhouse whitefly; melon aphid.

You can fight them with garlic infusions, onions or chemicals. If you detect signs of the disease in time and immediately begin treatment actively, there is a chance that most the harvest can be saved, should be reversed Special attention when choosing a variety of cucumbers for greenhouses - the packages usually indicate the plant's resistance to diseases and pests; you should definitely study this data.

Cucumber seedlings are falling. Constrictions on a cucumber stem

If you notice that young cucumber shoots suddenly fall off, and in older plants, under the leaves, the stem has become very thin, in the form of a constriction. What is it and how to preserve cucumber plants? The culprit is a fungal disease - root rot of cucumbers.

Root rot, which often occurs under unfavorable growing conditions for cucumbers. The cause of the disease may be:

watering cold water, frequent feeding of plants with mullein and mineral fertilizers, abundant and frequent watering, sharp fluctuations in day and night temperatures.

All this contributes to the proliferation of pathogenic soil fungi and their colonization of roots, tissues of the root collar and stem. In adult cucumber plants, the roots become black, “soaked,” and a brown ring-shaped constriction forms on the stem.

Blockage of blood vessels occurs, nutrients and water do not enter the plant and it dies. In young shoots (seedlings) of cucumbers, the subcotyledonous part of the stem becomes watery and thin; affected plants suddenly die.

In older plants (2-3 true leaves), a constriction forms under the leaves. Such seedlings are stunted in growth, and the leaves wither in sunny weather. But the infection mainly manifests itself in adult plants during the fruiting period of the cucumber.

How to deal with cucumber root rot

If you find signs of disease on cucumber plants, reduce watering, especially during periods of sharp temperature fluctuations (night and day), reduce feeding with mullein, water with heated water (20-24 degrees) in the morning or after 16, no later than 18 hours. Water the cucumbers not under the stem, but around the plant and throughout the garden bed.

Rake the soil around 5 cm from the diseased stem. Treat the stem with ash, crushed coal, chalk or fluff lime, add clean peat or sand. Change the location of planting cucumbers in open ground annually.

Spray greenhouses and greenhouses (all buildings) with a 4% solution of bleach. Before sowing the seeds, pour the furrows with a hot (60-70 degrees) intense pink solution of potassium permanganate.

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It’s such a shame when cucumbers in a greenhouse turn yellow. What is the cause of this disaster and what can be done to save the situation and still get a good harvest? If the yellowing of the leaves is not accompanied by wilting, most likely the cause is a lack of nutrients.Why do the fruits and leaves of cucumbers turn yellow? Experts identify several of the most common causes.

Failure to comply with the technology of growing cucumbers in greenhouses

Cucumber is a very moisture-loving plant (like pepper), so you should not neglect the rules of watering this vegetable. These rules are simple: to prevent the cucumbers from starting to get sick and turn yellow, the water for watering should not be cold (watering from a hose is not suitable). Water should be settled.

During the fruiting period, watering should be increased more often. In cool weather, plants are watered daytime, and on sunny warm days - in the morning. If the days are hot, then in the mornings only refreshing watering is done, and in the evenings - normal.

The depth of the moistened soil should be sufficient to root system cucumber plants developed deeply, and not superficially. Regularity of watering is crucial: you only have to miss watering the plants a few times, and this will immediately affect the quality of future fruits. So, lack of moisture leads to yellowing of the plant itself and the new ovary of cucumbers. Yellow spots indicate a lack of potassium, and light green spots are a sign of magnesium deficiency.

This means that cucumbers need to be fed. Weather conditions are often the reason why cucumbers turn yellow. Cold, wet weather caused by late frosts can damage plants.

If rotting of the ovaries occurs, you need to urgently remove the already faded flowers and treat the cut with potassium permanganate (solution). To prevent further bacteriosis, spraying is carried out with either 1% Bordeaux mixture or 0.4% copper oxychloride.

It's worth noting that peppers can also turn yellow and lose leaves if they are kept in temperature conditions up to +120°С long time.Soil composition is critical. Lack of nitrogen and poor soil - here common reason why plant development is disrupted.

It is important to ensure that there is no overdose in the amount of fertilizer, which, in turn, leads to oppression and yellowing of seedlings and their fruits. Before planting cucumber seedlings and after the harvest is harvested, manure must be applied to the soil. And during the growing season, fertilizing with complex mineral fertilizers containing phosphorus, fluorine and potassium, and liquid mullein is considered mandatory.

Damage to plants by various diseases or pests

Powdery mildew. If light, resembling white coating spots that gradually increase in size are a sign of infection. The leaf dries and turns yellow. How to deal with this trouble?

If you don't worry about destruction measures powdery mildew, next season she will certainly make herself known. Fungicide preparations “Topsin”, “Bayleton”, “Karatan” will help. The main disease of cucumber in our area, in which the leaves turn yellow, is downy mildew (downy mildew). It is also worth paying attention to cucumber varieties that are resistant to this disease. Fusarium wilt.

A dangerous fungal disease that causes the death of cucumbers in a greenhouse. Penetrating into the capillaries of the plant, the spores of this fungus completely block the access of food to the fruits and leaves. In greenhouses where infection has occurred, a complete replacement of the soil is required.

Works well against these pests special drugs: “Belofos”, “Arrivo” and the like. Root rot. The leaves, both of young plants and adults, begin to turn yellow from below. This is caused by significant temperature differences between day and night.

The cause may be watering with too “cold” water. Weakened plants become sick first, then the infection begins to spread through the soil to other cucumbers.

Preventive treatment (twice) with Previkur in the root area can prevent this unpleasant disease. Downy mildew (pernosporosis). This disease, common in melons and cucumbers, appears in greenhouses under conditions high humidity air and soil, against the background of dense planting of seedlings.

Affected fruits shrink and turn yellow. The first signs of damage may appear immediately with the onset of fruiting. In this case, the crop may be completely destroyed.

How can you tell if your plants are sick? Acute-angled, dark green spots. Preparations to combat pernosporosis - Bordeaux mixture or copper chloride (for the first treatment), "Bravo", "Avixil" (for the second treatment after 7 days).

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Other reasons:

Plants are overloaded with ovaries. In a greenhouse, cucumbers and peppers develop very quickly. But, in order to prevent the fruits from turning yellow, you should not leave more than 25-30 ovaries for further development.

By removing new shoots in a timely manner, delays in the development and formation of greens can be prevented. If this rule is not followed, the result may be underdeveloped, small and yellow fruits. The fertilization process has not taken place sufficiently. This happens when hybrid varieties that require artificial pollination are used in a greenhouse. https://www.youtube.com/watch?v=J84NeIvz16ICucumbers, like peppers, also turn yellow naturally when they reach their maturity, but are mainly used for food cucumber fruits are only green. This list of reasons why cucumbers turn yellow in your greenhouse will help you choose best way, how to preserve your harvest. Having listed the main reasons why cucumbers turn yellow in a greenhouse, we will consider in more detail each of the listed problems.

Violation of agrotechnical conditions

Low temperatures and frosts

Cucumber, as you know, is a warm and moisture-loving plant. In conditions middle zone, especially at the end of May, the so-called « return frosts» .

Cucumber seedlings planted under film covers or in greenhouses may not only turn yellow, but also stop growing and developing. To avoid cucumber leaves turning yellow in the greenhouse, it is necessary to additionally cover the planted plants with lutrasil or bubble wrap.

Many gardeners, in sub-zero temperatures and frosts, place plastic bottles with hot water, in order to maintain a normal temperature for the growth and development of cucumbers. Attention: It is important to remember that this plant prefers a temperature within +22+260C for its development. If the temperature drops below +140C, or above +420C, the plant stops its growth and development.

If the temperature is below -10C, the cucumber seedlings will die. Thus, in order to protect cucumbers planted in a greenhouse from frost and low temperatures, they should be additionally covered with a film placed on the arcs or with a special non-woven covering material such as lutrasil, agrotex or spandbond. This is what will help maintain an acceptable temperature for plants in the greenhouse.

Lack of mineral elements in the soil

Also, the reason why the leaves of cucumbers in a greenhouse turn yellow may be insufficiency minerals in the soil in which the plants were planted. As a rule, the leaves of cucumbers in a greenhouse turn yellow due to a lack of nitrogen.

Yellowing begins with the leaves having a lighter color, and then completely turning yellow, both the veins themselves and the entire space of the leaf between them. Subsequently, all the vines of the plant turn yellow.

Another sign indicating a nitrogen deficiency in the soil is the irregular, “hook-shaped” shape of the fruit. A lack of nitrogen in cucumbers can be caused by excessive application wood ash, potash fertilizers or superphosphate.

In order to avoid nitrogen deficiency in cucumbers, it is recommended that cucumber seedlings, a few days before planting in greenhouses, be fed with fertilizers and sprayed with a solution of microelements (see How to choose the right fertilizers for cucumbers in a greenhouse). When digging up a greenhouse in autumn and spring, it is necessary to add add rotted manure at the rate of two to three buckets per 1 m2. This will help avoid nitrogen starvation in plants.

If manure was not introduced during the digging process, then before planting the seedlings in the greenhouse, you can add rotted mullein to the soil, and throughout the growing season, feed the plants with an aqueous solution of mullein or chicken droppings, as well as an infusion of herbs, which is also called “herbal tea." It will also help eliminate nitrogen deficiency in the soil by applying mineral fertilizers containing nitrogen.

The leaves of cucumbers turn yellow in greenhouses and greenhouses even when too much mineral fertilizer is added to the soil. Before applying any fertilizer, carefully read the manufacturer's instructions on the package.

Insufficient watering

Cucumbers are moisture-loving plants and require both frequent watering and high humidity in the greenhouse or greenhouse where they are grown. However, watering these plants should be done only with warm and settled water.

Cucumber leaves turn yellow in a greenhouse both from watering with cold water and from insufficient water. At a time when active fruiting occurs, watering should be increased.

It is necessary to moisten the soil quite deeply, since it is deep penetration water will contribute to the development of not only the surface, but also the deeper root system of plants. Irregular and insufficient watering will affect both the leaves themselves and the ovary and fruits of cucumbers.

Poor pollination

One of the reasons why cucumber ovaries turn yellow in a greenhouse may be poor pollination. flowering plants. This can happen due to the fact that only artificially pollinated plants were planted, as well as due to the lack of ventilation or access for insects to pollinate the plants (see How to attract bees to grow a good harvest).

In this case, you can use spraying dissolved in water boric acid(5 grams per 10 liters of water), or drugs "Bud" or "Ovary". Natural methods include spraying with sweet water (one tablespoon of sand or honey dissolves in two liters of water), which will attract insects.

Next season, in the greenhouse in which you plan to plant cucumbers, plant dill or some honey plants, for example, borage, hyssop. These plants will be able to attract insects to the greenhouse, which will be able to pollinate the plants and promote the formation of normal ovaries.

Plant overload with ovaries

In the literature devoted to gardening and growing cucumbers in greenhouses, when asked why cucumbers turn yellow in a greenhouse, they answer that it is not advisable to leave more than 20-25 ovaries on one plant at a time. This is due to the fact that cucumbers develop quite quickly in greenhouse conditions. For many hybrid varieties It is possible to form more than one hundred and fifty ovaries on one plant at a time.

It is necessary to pinch out new shoots in a timely manner to allow cucumbers to form and ripen normally. If excess shoots and ovaries have not been removed, the fruits may develop an unattractive shape, and cucumbers in the greenhouse may turn yellow.

Damage to plants by insects or fungal infections

So, let's figure out what insects and diseases can harm cucumbers, and how to deal with them (see Diseases of cucumbers in a greenhouse, causes and methods of treatment).

Fungal diseases

Fusarium wilt or fusarium is a fungal disease

This disease manifests itself as follows: cucumbers sprout normally and grow well, but as soon as the ovaries begin to appear, the leaves of the cucumbers in the greenhouse first turn yellow, after which the vines dry out. The fungus that causes this disease penetrates the plant and releases toxins that limit the supply of nutrients and trace elements to the leaves and stems.

The way to combat this fungal infection is regular shift varieties planted in the greenhouse, as well as partial replacement of the affected soil. Powdery mildew is also a fungal disease.

In this disease, the fungus blocks photosynthesis processes in the plant. First of all, small light spots appear on cucumber leaves, which gradually spread to the entire surface of the leaf.

On all leaves of the plant, a whitish or reddish coating is observed on the upper surface of the leaf blade. After which the leaves of the cucumbers in the greenhouse turn yellow and dry out. To prevent the disease from visiting your greenhouse next season, you need to take a number of measures. First of all, when choosing cucumber varieties for the next season, pay attention to the resistance of a particular variety to powdery mildew, and also annually treat the soil in the greenhouse with potassium permanganate or green manure.

Downy mildew (pernosporosis)

The appearance of such a disease in greenhouses is facilitated by very densely planted plants, as well as excessive humidification of the air and soil in the greenhouse. The first signs of the development of downy mildew are the appearance of yellow and light spots on the leaves, which are limited by the veins.

Subsequently, the spots become oily and light yellow, and eventually turn brown. On the underside of the leaf blade, in those places where there are spots, a grayish-brown coating forms. If no measures are taken, the plant will die within a few days.

If cucumbers in a greenhouse turn yellow, root rot may also be the cause of this phenomenon. Plants at any stage of development can suffer from this disease.

The reason for such damage to cucumbers can be a significant difference in night and day temperatures, as well as watering the plants with cold and unsettled water. Weakened plants are the first to be affected, and then other plants become infected through the soil. In order to prevent plants from being affected by this disease, it is necessary to treat the root area with Previkur twice per season, according to the instructions.

Insect pests

melon aphid

This pest prefers to “infest” bottom side cucumber leaves and feeds on plant juice, which is why cucumbers turn yellow in a greenhouse. The melon aphid poses a threat to cucumbers throughout the summer season.

Spider mite

This pest appears primarily on inside cucumber leaf, where it weaves small webs. First, white or light-colored yellow spots, and then the leaves become completely covered with yellow spots and dry out. Throughout the warm days, spider mites multiply and if you do not fight them, for example, with the preparations “Akarin”, “Tsimbush”, “Fitoverm” and others, then you can lose all the plants in the greenhouse.

Lump sulfur and kerosene. Respirator.

The first step is to treat the greenhouse, and wooden iron frames are treated differently. Iron frames and components need to be painted with regular paint. water-based paint, wooden frames must be treated with vitriol.

Use a shovel and garbage bags to remove the soil. After cleaning, the soil needs to be dug up, and the sooner the better. This will determine how much the soil freezes in winter and is cleared of the microorganisms that have colonized it.

You also need to fertilize the soil immediately. It is better to set fire to the earth collected in bags; it will not bring more benefit. It is necessary to update the soil in this way every 3 years for good harvest cucumbers in a greenhouse. A procedure such as fumigation will help to completely disinfect the soil in the greenhouse.

It is carried out by setting fire to lump sulfur mixed with kerosene in special containers. Care should be taken to ensure that all air passages in the greenhouse are blocked.

This procedure is carried out at a temperature no higher than 18°C. After 4 days, the greenhouse will need ventilation. It seems that all these methods are not very important, but the yield directly depends on properly prepared soil.

Cucumbers will not grow in contaminated greenhouse soil. The soil is also treated by spraying with formaldehyde solution. The ratio for cooking with water is 1:1.

This method is effective in the absence of draft wind. The use of bleach will help in disinfection. This method is called wet, ratio: 1 kg per 11 liters of water. Moreover, this method will help clean not only the earth.

After soaking, the lime should completely dissolve. This happens after 1.5 weeks. Then, without sparing the solution, all the holes are watered. What remains at the bottom of the bucket is an excellent material for processing frames.

Another method that contains lime components is to sprinkle dry lime powder on the beds at a rate of 50 g per 0.5 m. Such methods are guaranteed to lead to the destruction of fungi, bacterial and mold microorganisms, and various types of mites. In specialized stores you can purchase preparations for such treatment methods. In situations where the preparation of the soil cover is postponed until spring, it is necessary to apply manure fertilizer, which has undergone biological and thermal treatment, before digging.

Error No. 1 - the soil in the greenhouse is not updated

Scheme for preparing fertile soil for a greenhouse. All the methods described above indicate that a big mistake can be made when planting cucumbers in a greenhouse if the soil is not updated. At the same time, the fruitfulness of the crop is next year will be under threat.

It’s better not to be lazy and, after processing, prepare the soil in the greenhouse in advance. Accumulating microbes and bacteria contribute to the development of various fungal diseases, such as downy mildew.

It affects seedlings, and in subsequent years there will be no harvest if measures are not taken to clean the soil. For example, because of it, green cucumbers (4-6 pieces) become distorted and dry out as soon as they start. A very common human mistake is damage to the rhizomes of cucumbers.

This culture has a long adaptation period. That's why the best option To plant cucumbers in a greenhouse, you need to count the seedlings; their approximate age is 25-36 days.

Such “youth” quickly master and begin to bear fruit. If you use the seed planting method, you need to remember that the greenhouse soil must be sufficiently warmed up to avoid seed rotting. The culture is very afraid cold weather, and planting seeds in cold soil will lead to nothing but rotting. In some cases, you need to wait for good weather conditions, even if the landing occurs later than usual.

Mistake #2 - incorrect landing

To save space in the greenhouse and produce more vegetables, people plant cucumbers very close to each other. So they end up in the same bed different types varieties, but this is wrong.

For good growth and fruiting, it is necessary to maintain certain indicators of temperature, ventilation and lighting. The distance between the bushes should be at least 20 cm so that the plants breathe and the bushes grow without interfering with each other's reach. sun rays, and the rhizome grew as it was convenient for it. The cucumber, which grows in a greenhouse, really loves organic fertilizers.

If it is not possible to purchase them, the use of manure will be a very good substitute for such organic fertilizing. If there is a problem with manure, then the solution is to build a hole in which you need to put organic waste - fallen leaves, weeds and straw.

When planting, you cannot use different species in the same bed. When purchasing seeds, you need to pay special attention to the growing instructions, where you can find information about whether to place the crop together with another or not. Incorrectly planted plants begin to hurt.

Mistake #3 - chemical treatment and improper treatment

Cucumber loves to be fertilized. Plants of some varieties even stop their development without organic feeding. Top dressing is good because it saturates the soil with all the nutrients that are so necessary for growth and harvest.

Moreover, feeding should be done gradually and constantly. If you throw all the fertilizers into the holes at once, you can only cause harm. Feeding occurs once a week. It is necessary to increase the amount of fertilizer if there is a sign that the crop is starving.

When feeding repeatedly, it is necessary to water the plant abundantly. Cucumbers love water very much. It’s no secret that insufficiently watered fruits will be bitter.

You can refuse to use chemical treatments, but then you should plant disease-resistant cucumbers. If the plant does get sick, gardeners immediately try to treat it by spraying and filling it with unnecessary medicine. Cucumbers need to be treated throughout the season, and evenly.

As soon as the leaves appear, the first treatment occurs. The second - after 3 weeks, the third - before flowering. And the last treatment is 18 days before the greens appear.

Why do cucumber seedlings disappear?

Why do cucumber seedlings disappear in a greenhouse? Firstly, it may be broken temperature regime and recommended air humidity. Secondly, the cause of plant death may be one of the diseases to which they are prone to be exposed.

In order to determine the exact cause, you need to know more information about what exactly is happening to them. Pay attention to whether they are affected by any insects, if so, then check necessary processing recommended in such cases.

The leaves of the plant will also tell you a lot: if they dry out, then they lack moisture; and if they rot or become covered with mucus or plaque, then most likely the air humidity in the greenhouse is increased. Measures should be taken after you find out the true cause of their death. 3. Disease and pests When pests are detected or infected with any disease, mandatory treatment of plants with appropriate solutions and preparations is necessary.

4. Yellowing of cotyledon leaves A clear sign of lack of light. Change the location of the seedlings.

What to do if the tomato seedlings turn yellow

As soon as you notice that cucumber seedlings are turning yellow, urgently inspect the plants to identify the cause and take action. There is no need to put it off until later; perhaps tomorrow it will be impossible to correct the situation.

A variety of pests are very common in the garden, because these are their natural habitats. They can be brought into the house from the street, for example, from...

Cucumbers grown at the dacha are fragrant and healthy. They taste significantly different from vegetables bought in the supermarket. But growing healthy cucumbers is not so easy; the plant is susceptible to many diseases.

Often gardeners are faced with the problem that the leaves of cucumber seedlings turn yellow. The problem begins when the second true leaf appears. The second leaves grow, and the first ones begin to change pigmentation.

Moreover, the issue may not be at all in the substrate in which the seedlings are planted. So why do cucumbers get sick at an early stage of development?

Why do cucumber leaves turn yellow?

There can be several reasons for burning leaves, the main ones include:

Lack of potassium, nitrogen, sulfur, calcium, manganese in the soil. Imbalance of nitrogen and potassium, correct ratio elements 1 to 2. An excess of nitrogen affects the pigmentation of foliage and can lead to ammonia poisoning. Insufficient watering affects the yellowing of seedlings in the same way as severe waterlogging. Temperature changes. If the temperature in the root zone drops below 17 degrees, then the plant is not able to accept micro and macro elements from the soil. At this temperature, even if all the useful elements are in the soil, they do not enter the stem. Poisoning by toxins. Some farmers place seedlings on foam boards. Yellowing may be caused by poisoning chemical compounds, which are released by the insulating layer, since the roots of the plant are in contact with it. Fertilizer getting on the foam can lead to the release harmful substances, which is dangerous not only for seedlings, but also for the harvest. Seedlings can be cramped in a peat cup, so many summer residents immediately sow seeds in the ground. The roots need space and adequate nutrition. Yellowing of the leaves may indicate that it is time to replant the plant. Lack of light.

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Cucumber leaves turn yellow: what to do?

Balance the doses of fertilizers, do not exceed the ammonia content in the solution. If there is a lack of nitrogen, you need to fertilize the plant with Vermistim or Azogran. If you use a foam substrate, then cover it with film on top. If the seedlings grow on the balcony, you can use lighting.
Don't forget to monitor the microclimate. Cucumbers love water, so don't skimp on watering. However, remember that the plant needs to be watered only with warm water, outside temperature. If you water the plant with cold water, diseases cannot be avoided. At the seedling stage, the plant is especially sensitive to potassium deficiency; if you do not monitor the development, the cucumbers will grow irregular shape. The best solution for cucumber seedlings is a nutrient solution based on complex fertilizers. For example, Kemira Hydro.

But cucumber leaves turn yellow at the edges not only of seedlings, but also of adult plants. This may be due to the fact that the plant is fully mature. If it's summer heat, and cucumbers are poorly watered, then yellowing is a natural process.

Read also: Having listed the main reasons why cucumbers turn yellow in a greenhouse, let’s look at each of the listed problems in more detail.

Violation of agrotechnical conditions

Low temperatures and frosts

Cucumber, as you know, is a warm and moisture-loving plant. In the middle zone, especially at the end of May, so-called "return frosts" .

Many gardeners, in sub-zero temperatures and frosts, place plastic bottles with hot water under such shelter in order to maintain a normal temperature for the growth and development of cucumbers. Attention: It is important to remember that this plant prefers a temperature within +22+260C for its development. If the temperature drops below +140C, or above +420C, the plant stops its growth and development.

If the temperature is below -10C, the cucumber seedlings will die. Thus, in order to protect cucumbers planted in a greenhouse from frost and low temperatures, they should be additionally covered with a film placed on the arcs or with a special non-woven covering material such as lutrasil, agrotex or spandbond. This is what will help maintain an acceptable temperature for plants in the greenhouse.

Lack of mineral elements in the soil

Also, the reason why cucumber leaves turn yellow in a greenhouse may be a lack of minerals in the soil in which the plants were planted. As a rule, the leaves of cucumbers in a greenhouse turn yellow due to a lack of nitrogen.

If manure was not introduced during the digging process, then before planting the seedlings in the greenhouse, you can add rotted mullein to the soil, and throughout the growing season, feed the plants with an aqueous solution of mullein or chicken droppings, as well as an infusion of herbs, which is also called “herbal tea." The application of mineral fertilizers containing nitrogen will also help eliminate the lack of nitrogen in the soil.

Insufficient watering

Cucumber leaves turn yellow in a greenhouse both from watering with cold water and from insufficient water. At a time when active fruiting occurs, watering should be increased.

It is necessary to moisten the soil quite deeply, since it is the deep penetration of water that will contribute to the development of not only the surface, but also the deeper root system of plants. Irregular and insufficient watering will affect both the leaves themselves and the ovary and fruits of cucumbers.

Poor pollination

One of the reasons why cucumber ovaries turn yellow in a greenhouse may be poor pollination of flowering plants. This can happen due to the fact that only artificially pollinated plants were planted, as well as due to the lack of ventilation or access for insects to pollinate the plants (see How to attract bees to grow a good harvest).

In this case, you can use spraying with boric acid dissolved in water (5 grams per 10 liters of water), or drugs "Bud" or "Ovary". Natural methods include spraying with sweet water (one tablespoon of sand or honey dissolves in two liters of water), which will attract insects.

Plant overload with ovaries

In the literature devoted to gardening and growing cucumbers in greenhouses, when asked why cucumbers turn yellow in a greenhouse, they answer that it is not advisable to leave more than 20-25 ovaries on one plant at a time. This is due to the fact that cucumbers develop quite quickly in greenhouse conditions. In many hybrid varieties, it is possible to form more than one hundred and fifty ovaries on one plant at a time.

Damage to plants by insects or fungal infections

So, let's figure out what insects and diseases can harm cucumbers, and how to deal with them (see Diseases of cucumbers in a greenhouse, causes and methods of treatment).

Fungal diseases

Fusarium wilt or fusarium is a fungal disease

The way to combat such fungal infection is to regularly change the varieties planted in the greenhouse, as well as partially replace the affected soil. Powdery mildew is also a fungal disease.

In this disease, the fungus blocks photosynthesis processes in the plant. First of all, small light spots appear on cucumber leaves, which gradually spread to the entire surface of the leaf.

Downy mildew (pernosporosis)

If cucumbers in a greenhouse turn yellow, root rot may also be the cause of this phenomenon. Plants at any stage of development can suffer from this disease.

Insect pests

melon aphid

This pest prefers to “infest” the underside of cucumber leaves and feeds on plant sap, which is why cucumbers turn yellow in greenhouses. The melon aphid poses a threat to cucumbers throughout the summer season.

Spider mite

This pest appears primarily on the inside of the cucumber leaf, where it weaves small webs. First, white or light yellow spots appear on the leaf, and then the leaves become completely covered with yellow spots and dry out. Throughout the warm days, spider mites multiply and if you do not fight them, for example, with the preparations “Akarin”, “Tsimbush”, “Fitoverm” and others, then you can lose all the plants in the greenhouse.

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Often gardeners are faced with wilting of cucumbers, seemingly just yesterday. healthy plants they look lifeless, the leaves look like rags, the shoots have lost turgor. It’s a shame when this happens before the harvest or after planting the seedlings. I’ll tell you how to help such plants and prevent such a phenomenon in the future.

Among the reasons for wilting of cucumbers may be the following:

Insufficient watering in sandy soil;
Damage to roots by mole cricket;
Manifestation of white rot - unpleasant fungal disease. The mycelium enters the plants through the soil and begins to develop inside the stem, appearing on the surface of the leaves in the form of wilting and white spots with black dots. Sometimes it is confused with powdery mildew; the difference between white rot is that the leaves wither first; during the initial stage of powdery mildew, the foliage retains turgor;
The development of root rot, when the roots gradually die off, become unable to supply the leaves with nutrition, and as a result, the plant withers. Diseases are characteristic brown spots on the stele and foliage, and then its yellowing and wilting;
Poor-quality purchased land, when unscrupulous sellers sell waste soil from greenhouse farms, pumped with fertilizers.

How to keep plants healthy

Root and white rot spores are spread with the soil, ending up in the area with purchased seedlings and with the soil, so the main attention in the fight against diseases should be paid to soil cultivation.

Dealing with rot is easier than infectious diseases that fall into the garden with rain and wind.

There are a number preventive measures, which will allow you to never have to deal with wilting cucumbers, and not remember about diseases, for example:

Before placing cucumbers, I dig up the soil, treat it with phytosporin, then level it with a rake and water it again with the preparation;
I do not use purchased soil for cucumbers, I only use my own compost;
I add lime and ash to the soil, this will prevent the development of white and root rot;
I treat the greenhouse with a 40% formaldehyde solution if I notice the appearance of rot at least once;
I ventilate the greenhouse, the installation of automatic window openers helps me with this;
I water the plants only with warm water and in a timely manner;
I plant cucumbers on old place only after 3 – 4 years;
Before sowing, I soak cucumber seeds in a dark potassium permanganate solution;
I keep a distance of half a meter when planting cucumbers, place them in a checkerboard pattern and on a trellis for better ventilation;
In prolonged rainy weather, I sprinkle the soil with ash.

What to do if you find wilted cucumbers

Preventative measures are good, but what to do if the cucumbers are already withering in the garden?

These plants can be helped:

I cut off the affected shoots and leaves with pruning shears and disinfect them in a solution of potassium permanganate;
Stems with small lesions of white rot are coated with ronilan, rovral or sumilex mixed with chalk 1:1, chalk can be replaced with lime;
I increase ventilation in the greenhouse; in warm weather, I do not close the doors at night. For open ground cucumbers, I remove the cover, if any, for ventilation;
To prevent root rot, I douse the plants with phytosporin or gamair, alirin - b and sprinkle the soil with ash;
After a couple of days, I treat the cucumbers with one of the stimulant solutions;
When the cucumber mass is noticeably restored, a week later I feed the plants with an infusion of the herb, making it in a weaker proportion than usual: 1:10.

It will also be useful for general development Watch a video about why cucumbers wither:

Cucumbers are tasty and healthy vegetables. But their cultivation is fraught with a number of difficulties. It also happens that young, newly grown bushes die. But not experienced gardener doesn’t always know why cucumber seedlings dry out. And there are several reasons for this - diseases, improper planting, and pests. And you need to correctly understand what was the reason for this specific case. Otherwise, the cucumber seedlings will wither and it will not be possible to save it.

The first reason is trivial and not worth worrying about. Wilting leaves do not receive enough light. But light and water are what cucumbers constantly need. The seedlings are exposed to the sun, or, if they are planted on open ground, remove what obscures it. If the lower leaves, which are not exposed to light, dry out, carefully cut them off. And if there is not enough water, then the solution suggests itself - just water the cucumbers more often.

But yellowing is also caused by excess water in the soil. In this case, less water is poured out daily. Yellowing of leaves and drying out of seedlings may also be associated with soil quality. Firstly, this happens if the soil has a deficiency or excess of microelements necessary for cucumbers. Here is a list of reasons that lead to this effect:

Excessive soil fertilization. The roots of the plants are burned due to an excess of fertilizers, they begin to wither, and the leaves wither along with them.
Insufficiently fertilized soil. Due to a lack of necessary substances, cucumbers wither, and seedlings dry out and die.
Failure to comply with crop rotation rules. Cucumbers planted next to plants that deplete the soil dry out in most cases. Examples of such plants are potatoes and tomatoes.

In each of these cases, transplantation can save the seedlings. When the soil is depleted, additional fertilizers still help, but after the same nightshade seedlings it is better not to plant seedlings at all. Another situation in which plant replanting will be necessary is when bushes are close together. Because of this, cucumbers also wilt, and this is worth remembering.

Early or late replanting of plants also causes harm. When transplanted late, the bushes become too large, and their root system is no longer able to adapt to new conditions. In such a situation, the plants die. Seedlings also wither due to early planting in the ground. The fact that the plants do not have time to grow stronger and low temperatures. By the way, growing seedlings in cold conditions also leads to the leaves turning yellow and drying out.

Diseases of cucumbers leading to yellowing of leaves and drying out

There are diseases, the appearance of which will be the answer to the question of why cucumber seedlings dry out. All of them are fungal diseases, so experienced gardeners recommend using cucumber hybrids that are resistant to fungi. But in order to understand why cucumber seedlings die, it is worth knowing the symptoms of these diseases. It is also advisable to know how to deal with these diseases. So, here is a list of the most common ailments affecting cucumbers.

Powdery mildew

This is a fungus that develops due to temperature changes and watering seedlings with cold water. With powdery mildew, the leaves become covered with a white coating and turn yellow, and then the plant dries out. Prevention of this disease is to grow cucumbers in warm conditions, follow the rules of crop rotation and use only warm water for irrigation. To combat powdery mildew, fungicides, HOM and Topaz preparations are used. Powdery mildew does not threaten cucumbers when fungus-resistant hybrids are used.

Downy mildew

This disease is also called downy mildew. Signs of this fungus will be small yellow spots scattered across the leaves. Over time, the spots increase, the leaves turn yellow completely, and then the cucumbers dry out and die. The reasons for its appearance are the same as for powdery mildew, as is the prevention of the disease. For the fight, Bordeaux mixture, Ordan and Ridomil are used.

Anthracnose

This disease is also called copperhead. When it appears, spots appear on the leaves of plants, but not yellow, but orange color, copper color. This disease also affects adult plants, and then spots appear on the fruits. This fungus also infects cucumber seeds, so seed material is not collected from diseased plants. They fight this fungus using solutions of Bordeaux mixture and copper sulfate. Bordeaux mixture is used for prophylaxis, and copper sulfate- to cure fungus.

Fusarium

This fungus lives in the soil and can remain in it for a long time. It affects the roots of the cucumber bush, after which the plant’s leaves and stems begin to dry out and then rot. Young and weakened adult plants suffer from fusarium, and, like all fungi, fusarium develops in conditions of high humidity and strong temperature fluctuations. To combat fusarium, drugs such as Trichodermin and Phytocid are used. But it is recommended to treat the seeds with these drugs, because once the disease has developed, it cannot be stopped. All that remains is to burn the dried plants and disinfect the soil.

What pests cause cucumber seedlings to turn yellow and dry out?

Pests may also be the reason why young cucumber seedlings die. But an experienced gardener remembers that pests can provoke yellowing, but not cause it. main reason. It happens that a plant weakened by insects dries out due to disease. Therefore, after getting rid of insects, it would be useful to make sure that they were the main reason for the drying out of cucumber seedlings.

melon aphid

Aphids can destroy garden beds at incredible speed. Here's what gardeners say about it:

“If you don’t keep an eye on it, the melon aphid can deprive the entire cucumber harvest. When dealing with it, prevention is important. At home, it is better to heat the soil in the oven to get rid of the larvae of this pest. And dig up the area and freeze it over the winter.”

To combat aphids in a greenhouse or open ground, the soil is sprayed with potent insecticides. These are drugs such as Commander, Fufanon, Fury and others like that. Spraying is carried out before planting, and if the plants themselves are treated, then before the formation of ovaries. It should be remembered that these drugs can harm humans. The soil treated with chemicals is loosened to a depth of 3-4 cm.

Spider mite

This insect affects everything cultivated plants without exception, and the first thing that appears is a barely noticeable web on the leaves. Spider mite will eat cucumber leaves until all the seedlings dry out. And the main problem when fighting it is the survivability of the pest. Its eggs persist in the soil for up to five years. Therefore, in regions with cold winter It is recommended to freeze open ground, and for home planting roast the earth in the oven.

But dealing with ticks is not so difficult. This insect does not like water, so spraying the plants with an aqueous solution will help get rid of the pest. Even weak tinctures of dandelion, citrus fruits or garlic are useful here - they are harmless to the plant, but destructive to the mite. Also used chemicals the same type that help against aphids, but they are used only if the lesion is advanced and very severe.

Reasons for plants drying out in a greenhouse

Greenhouse cucumbers have the same reasons for wilting as those grown on a plot or in an apartment. Cucumber seedlings wither and dry out due to the fact that the temperature in the greenhouse is too low or high. Cucumbers also do not like lack of light, depleted soil and waterlogging. And greenhouse plants have all these problems. Soil depletion is especially harmful here. Due to the fact that plants are planted in the same soil year after year, even fertilizers do not always help.

Leaves wither in the greenhouse also due to insufficient pollination. This requires insects, and they often do not have access to the greenhouse. And artificial pollination does not always save. To guarantee a harvest, and also to prevent the leaves from drying out, bees and other insects of the same type are attracted to greenhouse cucumbers. To achieve this, a set of measures is carried out to prevent natural enemies of bees from entering the greenhouse. It also makes greenhouse plants attractive to these insects.

Conclusion

There are many reasons why cucumber seedlings dry out and wither. And in order to understand what happened to the plants, you need to correctly understand what hit them. It is also worth familiarizing yourself with the photos that show what a particular lesion looks like. After all, although all the symptoms are similar, each of them has its own characteristics. You need to know them.