We will analyze with you the signs of a lack of one or another element for cucumbers and, based on this, we will see in what cases and what to feed cucumbers at the stages of their growth and development.
Vegetable growers often observe changes in the color of cucumber leaves. And indeed, it speaks volumes: a border along the edge of the leaf and dark green veins - a lack of potassium; pale yellow color near the corolla of the flower - low phosphorus. Insufficient development of apical buds and the appearance of dome-shaped leaves means cucumbers lack calcium.

Change in leaf color, appearance of certain signs of deficiency in plants nutrients does not mean that there are not enough of them in the soil. The absorption of nutrients often depends on external conditions. For example, if you observe signs of nitrogen deficiency (leaves turn pale), then first of all you need to ensure that watering is done regularly. Overdrying of the soil leads to a partial attenuation of the activity of beneficial microorganisms and the disappearance of available nitrogen, which is why the leaves turn pale.

However, there is no need to rush to feed the plants. Fertilizing with fertilizers containing nitrogen, especially during the period of fruit formation, increases the content of nitrates in them, and the quality of the fruits noticeably decreases. Sometimes it is enough to start watering the cucumbers correctly and regularly, and within a week the color of the leaves is restored. Well, if things are really bad for the plants, then you can feed the cucumbers with ammonium sulfate or urea at the rate of 10 - 15 grams per 10 liters of water. You should not feed cucumbers before harvesting or on the eve of harvesting.

Appearance of leaves dome-shaped with a border along the edge often misleads gardeners, since exactly the same signs of disease occur in plants with damage to the root system. Therefore, before feeding cucumbers with calcium or potassium, it is worth checking what the roots look like. If you see that the roots have turned yellow, then feeding such cucumbers is unlikely to help. Most likely, it will further aggravate the situation, especially if the cause of the root disease is an increased concentration of elements in the soil solution, which occurs when mineral fertilizers are applied in excess of the norm.

But it may also be like this: the roots have a normal, white color, but the symptoms of potassium deficiency are not confirmed. This happens when, due to long cloudy and cold (below 15 degrees) weather, there is an outflow of nutrients from the leaves. The color of the leaves usually returns with the onset of warm days.

If, nevertheless, cloudy weather lingers, it is useful to foliar feeding complex fertilizers: you need to take 5 g of potassium chloride, 5 g of ammonium nitrate and 5 g of superphosphate, pre-infused in water for 24 hours, per 10 liters of water.

Cucumbers respond especially well to foliar feeding in the first half of the growing season. This feeding is carried out at the end of the day so that the moistened leaves are not damaged by sunlight.

Now a little about phosphorus fasting. Its signs appear very rarely. If superphosphate is added to the soil according to the recommendations, then the cucumbers will be fully provided with it. But still, we must remember that phosphorus is poorly absorbed when the soil is alkaline. The soil reaction can be easily checked using litmus paper. IN in this case the soil substrate should be acidified by adding sawdust or acidic peat.

Chapter 1. Why do cucumber leaves turn pale?

Lack of nitrogen. Signs of nitrogen deficiency are clearly visible in the spindle-shaped habit of plants. Growth is greatly inhibited, the vines are thin, hard, and quickly become woody. The leaves remain small and most of them point upward. Very few side shoots are produced. The ovaries rapidly fall off and some of the flowers die. First, on older leaves, premature yellowing of the leaf blade is observed. It quickly spreads to young leaves. With a later onset of nitrogen starvation, yellowing can also affect middle-aged leaves. With progressive nitrogen deficiency, the fruits become pale yellow in color. At first, the thinnest veins of the leaf still retain green color, but subsequently they also lose their green color and even new leaves acquire a lighter color. Some fruits lose their normal color, they are shortened in size and have a pointed end.

Excess boron. The first sign of excess boron intake into plants is the lemon-yellow color of the edges of old leaves. Later, small light yellow, fairly evenly distributed spots appear along the edges of the leaves between the veins. The rest of the leaf, especially the middle, retains its normal green color. These spots then become necrotic, and signs of excess appear on young leaves. The edges of the affected leaves bend down after some time. Tissue death until complete necrosis of the leaf occurs between the veins, but has no clear boundaries.
Iron deficiency. Signs of chlorosis appear on the youngest leaves of the main and side shoots. Only the main and lateral veins retain their green color. The entire plate becomes light green in color. Over time, the edges of the leaves become necrotic, and chlorosis spreads to older leaves. The fruits show no signs of iron deficiency.
Excess potassium. Visual signs of excess of the specified element appear along the edges of older leaves.
Calcium. A lack of calcium in cucumber causes the appearance of small, dark green leaves with short internodes. Then the young leaves lighten at the edges, and at the same time narrow light stripes appear on the leaf blade between the veins. They expand, lose their green color, and necrosis. The veins and the adjacent part of the leaf retain an intense green color. The edges of the sheet are curved down.
Copper. A lack of copper causes the tips of the leaves to turn white; the plants lose turgor and wilt.
Molybdenum. With a lack of molybdenum, a weakening of the green color of the leaves is observed. The deficiency of this element is accompanied by a violation of nitrogen metabolism.
When a plant lacks potassium, the edges of its leaves first turn yellow and then turn brown. If the soil is peaty, the leaves begin to wrinkle. With nitrogen starvation, the leaves are stunted in growth, turn pale, especially the lower ones, and the fruits are shortened and pointed (you've probably had cucumbers like these!).

A lack of phosphorus is accompanied by a sharp slowdown in the growth of your green wards, the leaves become smaller, become dense, watery spots appear on them, and after some time the damaged leaves die.

Chapter 2. How to deal with this problem

Everyone knows that lack of nutrients negatively affects the growth and development of plants, which naturally affects the quantity and quality harvested. Today I will talk about how our most common favorite vegetables react to a lack of essential nutrients - nitrogen, phosphorus, potassium. And also about what to do if you external signs determined the lack of one or another element.
What to do if a deficiency of elements is detected in a plant?
Needs to be prepared nutrient solution small concentration from 0.2 to 0.3%, that is, take from 20 to 30 g per 10 liters necessary fertilizer. More often, a deficiency of elements is observed on soils poor in humus, but on such soils it is dangerous to apply large doses of mineral fertilizers, as this can lead to poisoning of the plant. A good effect is achieved by spraying the leaves (foliar feeding) with a weak fertilizer solution (10 g per 10 l).
Can an excess of some fertilizers cause a deficiency of others?
Most often, plants react to an imbalance of nitrogen and potassium. With an excess of nitrogen, plants “fatten”, that is, they form large leaves, powerful stems, and abundant flowering, but flowers set later and fruits ripen more slowly. An increased content of potassium in the soil leads to accelerated flowering and fruiting, and the plants are small in size, the overall yield is reduced. High calcium content in the soil leads to reduced absorption of manganese, copper and zinc.
Which vegetable crops most sensitive to chlorine?
Such crops include cucumber, pepper, tomato, and potato. It is undesirable to add potassium salt and potassium chloride to these crops. They should be replaced with potassium nitrate or potassium sulfate. You can use complex fertilizers that do not contain chlorine.
How do fertilizers affect the quality of vegetables?
Leafy vegetables with a lack of nitrogen sharply reduce the yield, the leaves become hard and rough, and an excess of nitrogen fertilizers with a lack of phosphorus and potassium fertilizers, as well as poor lighting, leads to the accumulation of nitrates, cabbage heads are poorly stored. With excess nitrogen nutrition, the shelf life of root crops sharply decreases.
Increased doses of phosphorus fertilizers improve the quality of fresh and pickled cucumbers and tomatoes. With a sufficient amount of potassium in the soil, the taste of a tomato increases.
What should be done when the first signs of phosphorus deficiency are detected?

It is necessary to add superphosphate to the soil (1 square meter– 1 tablespoon), or phosphorus flour (per 1 square meter – 2 tablespoons), or any other fertilizer containing phosphorus. It should also be noted here that advance liming of acidic soils improves phosphorus nutrition of plants.
Before fruiting, you can feed the cucumbers with potassium fertilizers (20 g per 10 liters). Repeat fertilizing with water 3-4 times a month, if the condition of the plants requires it. A good mineral-organic fertilizer with microfertilizers is a solution (in 10 liters of mullein) of 1 kg of water, 30 g of phosphorus fertilizer, 20 g of potassium, 2 g of copper permanganate and 1 g of potassium sulfate and boric acid.

If the cucumber vines are thin and the leaves are small and pale, then feed them with nitrogen. If the growth of vines is strong and fruiting is delayed, feed with phosphorus and potassium. If there are few ovaries, it is necessary after
feeding with bird (mullein) droppings, reduce the temperature in the greenhouse to 18, ventilate (degrees at night). If there are a lot of ovaries, they require intensive feeding with mullein (if), then with manure, a change in the feeding scheme - a transition from alternating once with organic matter and mineral fertilizer to two 2: 1 (scheme of once with organic matter, once with mineral fertilizer).

Apply both mineral and liquid organic fertilizers at the roots, without contaminating the leaves.

Don’t forget about foliar feeding, especially those in which development is prevented dangerous diseases, - downy mildew, etc. A solution (per 10 liters of water) of 20-30 g of urea and 2 g of copper sulfate, boric acid and potassium permanganate.

Chapter 3. Prevention of pale leaves

It is necessary to help the plants and feed them. But who knows what?

Why recommended doses of fertilizers are not always effective. The reason for this is that our soils are very different in their chemical composition, and the content of vital nutrients in them is not the same. All nutrients are divided into macro- and microelements. Macrofertilizers are applied in large quantities. These are nitrogen, phosphorus and potash fertilizers. Doses of microfertilizers are small, but their role in plant life is also great. They are part of vitamins and enzymes - living catalysts for reactions in organisms, both plants and animals.

External signs of lack of fertilizers various plants vary, but there are general changes in growth and development caused by a lack or excess of nutrients. Visual diagnostics is a simple and accessible method for every amateur vegetable grower to determine the fertilizer needs of plants. I want to draw their attention to external signs of a deficiency or excess of certain chemical elements in different cultures.

With a lack of nitrogen, suppressed growth, short and thin shoots, small inflorescences, weak foliage of plants, weak branching, and small leaves of a pale green color are observed. Moreover, the yellowing of leaves begins with the veins and the part of the leaf blade adjacent to them, and parts of the leaf remote from the veins may still retain a light green color. With a lack of nitrogen, leaf veins are also light. Yellowing begins with the lower, older leaves.
By external signs, one can judge the lack of a particular nutrient in the soil and the need of plants for fertilizing, which should be carried out without delay as soon as the plants show the first signs of deficiency, and it is better to not allow these “SOS” signals to appear at all. However, slowing growth and changing appearance plant problems are not always caused by a lack of these nutrients in the soil. Similar symptoms are sometimes caused by damage to plants by pests or diseases, as well as unfavorable conditions cultivation (drought, low temperature, etc.). It is important to be able to differentiate these changes from signs of nutrient deficiency.

Today, trade organizations offer many different fertilizers to amateur gardeners. Don't rush to buy the first one you come across. It is good to use complex fertilizers, especially with the addition of microelements. For each crop, a certain composition of fertilizers is released at different stages of development. And what is suitable for potatoes in the second half of summer is not suitable for feeding young cucumber plants in greenhouses. In addition, different soils also determine for the same crop different composition fertilizing

Usually they do wet feeding. The prescribed amount of fertilizer is diluted in a bucket (or liter) of water and the plants are watered with this solution over an area of ​​1 m2, and then a bucket of clean water is poured onto the plants to prevent burns. If your plants are very behind in development, it makes sense to do foliar feeding. The concentration of the solution should not exceed 1% in this case. Nutrients will be absorbed by the leaves through the stomata and immediately used by them. Dry fertilizing before rain or watering should be done carefully. For this purpose, you can adapt a dense plastic bag small size. Carefully use scissors to cut off a small corner of the package. Pour fertilizer into the bag, after thoroughly mixing and breaking up all the lumps. We carry this bag between the rows of cucumbers, carrots, parsley, onions and other crops, almost touching the ground. Fertilizers through the cut hole will be evenly poured onto the soil surface and there will be no danger of them getting on the plants even if the rows are close together.
In order for cucumber seedlings to develop normally, they need to be fed. The first fertilizing is recommended 8-10 days after emergence. If you prefer to feed cucumbers with organic fertilizers, then it is advisable to add 20 g of superphosphate per 8-10 liters of mullein solution to the mullein solution (1:10).

To feed cucumber seedlings, you can also use complex fertilizers, which contain not only nitrogen, phosphorus, potassium, but also other micro- and macroelements necessary for plant nutrition.

In the future, fertilizing of cucumber seedlings is carried out once every 2 weeks. Fertilizing should not be done on dry soil or in the morning. It is recommended to water the plants in the morning and fertilize them in the evening. If you are using mineral fertilizers for the first time, do not exceed the dosage recommended by the manufacturer. The recommended dose of fertilizer can even be halved, otherwise it is easy to burn tender plants.
Try to maintain crop rotation.

Do not plant cucumbers in the same place from year to year, do not plant them after zucchini or pumpkin, otherwise the likelihood of “catch” increases significantly fungal disease. Water your cucumbers promptly and abundantly.

If you are on the site only on weekends, take the time to mulch the beds well with weeds or mown grass. A thick layer of mulch will prevent moisture from evaporating and will also provide the cucumber roots with additional nutrition and warmth.

After emergence of shoots in the 3-4 leaf stage (and then every 10 days), spray the cucumbers with the following composition: 20 grams laundry soap, 1 liter of milk and 30 drops of iodine per 10 liters of water. Another option for preventive spraying: soak a loaf of bread in a bucket of water in the evening, knead the bread in the morning and add a small bottle of iodine.

http://www.gardening.kittens-world.ru/pochemu-na-l...lit-nedostatok-jelementov.html

Cucumber leaves are like a litmus test for determining their health. In addition to water, air and sun, cucumbers need macro- and microelements throughout the growing season. And, if the leaves are faded, deformed or have yellow spots or borders, then this is not necessarily some kind of cucumber disease. This article will help you understand why cucumber leaves have a yellow border or other shades, and will also tell you how to correct this effect and get excellent harvest cucumbers

Yellow border on cucumber leaves.

This year I myself had to face this problem. The spring was protracted, the beginning of summer was cold: the cucumbers were slowly germinating, and when I finally waited for the first real leaves, I saw this yellow border along the edge of the cucumber leaf. I decided that this was due to lack of light and warmth. The leaves were pale and weak, it was difficult for them to even absorb the necessary nutrition.

The first reason is that if a yellow and then a brown edge appears on the leaves of cucumbers, it means they lack potassium.

I spilled the cucumbers from a watering can and sprayed them over the leaves with a weak pink solution of potassium permanganate, that is, potassium permanganate. Additionally, I scattered 1 tbsp of ash under each plant. Now the cucumbers are fine.

But there is a second reason for the appearance of a yellow border on cucumber leaves - a lack of boron. This happens when flowers and fruits already appear on the plant. The lack of boron can be determined not only by the leaves, but also by the ovaries, since in this case the flowers appear, they immediately wither and die, and the cucumbers themselves are crooked, delayed in development and have a yellow longitudinal furrow.

In this case, spraying on the leaf will help (you can try Boric acid or even better - Biochelate-Boron). Just be careful, since boron is a highly toxic element that, if overdosed, will cause leaf burns.

Cucumber leaves are pale, sometimes thin, and deformed.

Such leaves may appear at the beginning of the development of cucumber vine - this is a lack of nitrogen. At the very beginning of cucumber growth, feed it with nitrogen-dominated fertilizer. This can be carbamide (urea) or ammonium nitrate.

I do this - when planting cucumbers nearby, I dig a small furrow and scatter it into it. ammonium nitrate(or nitroammophoska). In the future, once when watering, I add 1 tablespoon of urea to the watering can.

“Among all mineral fertilizers, nitrogen fertilizers are the most dangerous in case of overdose: excess nitrogen accumulates in vegetables in the form of nitrates and nitrites, which are harmful to human health. Nitrates accumulate in plants not only when there is an excess of nitrogen, but also when there is a lack of molybdenum and iron, which contribute to the reduction of nitrate nitrogen (NO3) to ammonia nitrogen (NH4).” http://www.agroplus-group.ru

Cucumber leaves are small, light yellow-green, and can curl.

This can also happen at the beginning of the development of the cucumber vine or, conversely, at the end of the harvest, as well as with a very large number of fruits. This means that the leaves have become “impoverished” and have given away everything valuable that was embedded in them.

In this case, you need to give the plant a portion of microelements - zinc, calcium, sulfur. It is better if the fertilizer is in liquid form - in this case, quick help is needed - then you can not only spill it on the soil, but also spray and fertilize the leaves.

Cucumber leaves are “marbled”: the color is uneven, green light and dark spots alternate.

The leaves are deficient in magnesium. If you dust the soil before planting dolomite flour, and then once every 20 days, water them with a liquid solution of dolomite (1 tbsp per 8 l), then this will not happen. Dolomite flour is a good supplier of magnesium.

Cucumber leaves are small, gray-green, on adult plants there are brown spots between the veins, on young plants the leaves “look” up.

This is phosphorus deficiency. Cucumbers most of all need a regular supply of phosphorus. All the time they grow in the plant there is a very high consumption of all macroelements, and especially phosphorus - it is the key good quality fruits Feed the cucumbers with superphosphate or other phosphorus-containing fertilizer. In young plants, the leaves will unfold in a horizontal plane, which means they will receive more sun and light. Do this once every 10 days.

The veins on the leaves of cucumbers are dark green and stand out strongly on the surface of the entire leaf; the leaf itself can be light green or yellowish.

This type of leaves occurs due to a lack of manganese. Manganese is involved in the formation of chlorophyll and, like iron, copper, zinc is necessary for cucumbers for photosynthesis and respiration. Most often, manganese deficiency occurs in alkaline soils.

You will make your life much easier if you find a good complex fertilizer, with which you don’t have to rack your brains about why there is a yellow border on the leaves of cucumbers and what the lack of elements is in your cucumbers.

For myself, I discovered a very convenient to use, inexpensive and effective fertilizer brand "JOY". Fertilizer can be selected according to different type grown crops. "JOY" can be used in protected and open ground. It contains an optimally balanced amount of micro- and macroelements. "JOY" works throughout the entire vegetative period of plant development. Fertilizer helps to increase the yield by 30% and increase its shelf life, as well as restore the natural structure of the soil. In my case, the “JOY” - Universal bottle has a convenient dispenser cap, which is also important. And of course, when choosing a fertilizer, I paid attention to the “hazard class”, here it is IV (low-hazard).

To successfully grow cucumbers in a greenhouse, preventing the development of diseases, you need to take into account some factors that lead to weakening of plants, as a result of which they become more susceptible to bacterial, fungal and viral infections. The most common diseases in cucumbers and methods of their treatment and prevention should be considered. Having learned about the most effective drugs, you can decide what to spray the cucumber with in order to prevent the spread of diseases. To prevent diseases in cucumbers in a greenhouse, you need to monitor air humidity, temperature and the presence of nutrients in the soil. There may be several main causes of diseases of cucumbers in a greenhouse:

• increased air humidity; lack of nutrients in the soil; sudden temperature changes, including watering cold water.

Mosaic disease

The development of mosaic disease is promoted by sharp fluctuations temperature, lack of light and moisture in the soil. A viral disease that mainly affects leaves and fruits. It is transmitted through seeds and when diseased plants come into contact with healthy ones, and can be carried by insects.

Viruses penetrate plants through damaged tissue and remain in the soil and seeds. There are several strains of the virus; depending on the strain, symptoms may differ in the degree of deformation and the color of the mottling. The leaves may be slightly or severely wrinkled, with their edges curling down.

Mottling can be light and dark green, yellow or white. Due to the disease, cucumbers in the greenhouse set and develop poorly, often acquire a mosaic color and become deformed, but most often wither. The mosaic virus negatively affects the entire plant as a whole, its growth slows down.

The stems of the affected plant often crack. There are no effective methods to combat mosaic diseases. All that remains is to accept preventive measures, paying attention to varieties and hybrids that are resistant to mosaic.

To prevent the disease, only composted or sterilized substrates are used. In case of relatively mild infection, diseased areas should be cut out, and the spread of cucumber mosaic disease can be limited by spraying with skim milk. However, in case of severe infection, the plant should be destroyed.

Powdery mildew

Powdery mildew spreads quickly in cool, cloudy weather. Spores are spread by wind or water during watering. A fungal disease that manifests itself as a white coating on the leaves.

Over time, the amount of plaque increases until it completely covers the leaf, as a result of which photosynthesis is disrupted, the leaf turns yellow and dries out. Fungal spores can be spread by both wind and water during watering. With a severe degree of infection, spores may remain on the weeds or in the ground. This disease occurs due to the accumulation of infection when cucumbers have been grown in the same place for many years. Another cause of the disease can be high humidity in the greenhouse. To combat powdery mildew, it is necessary to remove the affected leaves and spray the cucumber with mullein solution: mix 1 liter of liquid mullein with 1 tbsp. l. urea, mix everything well and strain thoroughly. You can also use a weak solution of potassium permanganate - 1.5 g per 10 liters of water - to spray cucumbers in a greenhouse.

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Downy mildew or peronosporosis

This is a fungal disease that mainly affects leaves. It appears in the form yellow spots on top of the leaf, over time the spots turn brown. There is a gray-violet coating on the underside of the leaf.

Over time, the leaves wither, dry out and fall off. The development of this disease is facilitated by increased humidity and sudden changes in temperature, watering cucumbers with cold water. To prevent powdery mildew, it is recommended to use potassium and phosphorus fertilizers, ventilate the greenhouse more often, and avoid cold drafts. To combat downy mildew, it is necessary to remove leaves affected by the disease, stop watering. Sprinkle the soil wood ash, and spray the plants with Topaz solution in the ratio: 1 ampoule per 10 liters of water.

The fungicide “Oxychom” is also suitable: 2 tablets per 10 liters of water. After harvesting the last harvest, it is necessary to treat with a solution of copper sulfate, dissolving 3 tbsp. l. in 10 liters of water. Cucumbers must be sprinkled generously, and after 24 hours, removed and burned along with the roots.

Root rot in plants

Root rot is caused by increased humidity in the greenhouse, watering with cold water, and planting seedlings in cold soil. A fungal disease caused by the fungus Pythium De Baryanum Hesse. The source of infection is spores that can spread through the air, with splashes of water, as well as through the transfer of insects. The development of the fungus is facilitated by planting seedlings in cold soil, sharp fluctuations in temperature and humidity in the greenhouse, and watering cucumbers with cold water. It begins to spread from the root zone, in As a result, they first turn yellow lower leaves, then the whole vine dries up, the roots become covered with brown spots, rot and die, as a result the plant dies completely. To prevent the disease, it is recommended to plant cucumber seedlings in soil watered with a solution of potassium permanganate, in a ratio of 3-5 g per 10 liters of water. Watering must be done correctly and on time. To combat root rot, you can use the drug "Infinito 61 SC". A solution in a ratio of 5-10 g per 10 liters of water. The combined use of such drugs is quite effective:

1. Fitolavin-300, 20 g + Fundazol, 15-20 g per 10 l of water. Fitolavin-300, 20 g + Colfugo Super, 15-20 g per 10 l of water.

Gray mold disease

To combat gray mold, it is necessary to sprinkle the affected areas with a mixture of copper sulfate and wood ash. A fungal disease caused by the botrytis fungus (Botrytis cinerea Pers). Spores mainly spread through the air, and can also spread with splashes of water. The development of this disease is facilitated by poor ventilation, high humidity, a sharp drop in temperature, and watering with cold rainwater. The disease manifests itself in the form brown spots on the leaves, rotting stems, and wet brown spots appear on the fruits.

With high humidity, the affected areas become covered with a gray fluffy coating, which contains fungal spores, which can be carried by drafts, infecting neighboring plants. For prevention, it is recommended to plant cucumbers at a sufficient distance from each other, avoid getting water on the leaves when watering and regularly ventilate the greenhouse.

To combat gray mold, the affected areas are sprinkled with either just wood ash or a mixture of copper sulfate (1 tsp) and wood ash (1 tbsp). After this, the greenhouse is well ventilated. Another option to combat this disease is to coat it with a fungicide.

To prepare it you will need: 300-340 g of CMC glue, 30-40 g of fungicide and 10 liters of water. The mixture must be brought to a paste-like state by adding crushed chalk to it. If none of the methods help, the affected areas must be cut off and burned.

White rot (sclerotinia)

Cucumber stems affected by white rot must be cut out, partially removing healthy tissue. A fungal disease caused by the fungus Sclerotinia sclerotiorum. The source of infection is the soil in which the spores of this fungus persist and live for quite a long time. The development of the disease begins at the root part of the stem, watery wet spots form there, and over time they become covered with white cotton wool-like mycelium.

Next, the upper tiers of the plant are affected. White rot causes death and wilting of plants, rotting of fruits. To prevent infection by the fungus, it is necessary to observe optimal mode humidity and temperature in the greenhouse.

Since fungal spores can be in the soil, if possible, it is necessary to use calcined soil, and when planting seedlings in holes, you need to add potassium permanganate, dissolving 5 g in 10 liters of water. To combat white rot with mild damage, you need to mix chalk and potassium permanganate with the addition of water and treat the affected areas with the resulting paste. In case of severe damage, it is necessary to remove the affected areas, it is advisable to also include part of the healthy area.

Sprinkle the affected stems and areas with lime. But if the plant is very sick, it will be better to remove it along with a layer of soil to avoid infection of neighboring plants. When fighting white rot, it is also recommended to use drugs such as Rovral SP and Euparen Multi SP produced by Bayer.

Fusarium fungal disease

Measures to combat fusarium: watering warm water, soil disinfection, adding trichodermin to the holes when planting seedlings. A fungal disease caused by fungi of the genus Fusarium. Its sources are seeds and soil.

The development of the disease is facilitated by sudden changes in temperature, high humidity and lack of soil nutrition. Weakened plants are most susceptible to the disease. The causative agents of the disease enter from the soil first into small roots, then into larger ones.

From the roots, through conducting vessels, they enter the stem, reaching the leaves. The lower leaves of the plant wither, the edges of the rest become watery, and some areas turn light yellow or pale green. The stem becomes thinner and turns brown.

Soon the entire plant withers and dies. To prevent the appearance of fusarium, it is necessary to regularly ventilate the greenhouse and calcinate or freeze the soil before sowing or planting seedlings. In addition, it is recommended to sterilize tools with alcohol before work - used knives and garter material). If there are visible damage to the plants, fusarium is no longer curable. Affected plants must be destroyed immediately to prevent the spread of the fungus.

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Olive spot (cladosporiosis)

A fungal disease caused by the fungus Cladosporium cucumerinum Ellis & Arthur. Favorable conditions for the development of the disease are watering the cucumbers in the greenhouse with cold water, high air and soil humidity, low temperatures and drafts. This disease manifests itself in the form of oblong dry sores with a grayish-olive coating covering the stems.

Light brown spots appear on the leaves; later they are covered with a faint brown coating. Fruits are most affected. At first, oily depressed spots appear on them, then an olive coating develops, various ulcers of irregular shape form. To combat cladosporiosis, it is necessary to stop watering for several days, regularly ventilate the greenhouse, and spray the cucumber with a 1% solution of Bordeaux mixture, you can use “Oxyx” - 20 g per 10 liters of water.

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Anthracnose or copperhead

A fungal disease caused by the fungus Colletotrichum orbiculare. Its spores can spread with the wind, irrigation water, and can be carried by insects or on garden tools. The development of this disease is facilitated by high humidity and a lack of nutrients in the soil.

It begins with damage to the leaves; light brown spots with a border of a darker color form on them. Spots appear on the shoots, which expand and deepen over time, forming depressed spots, then they are bordered by a dark purple or brown rim.

Deep ulcers with pink mucus appear on the cucumber fruits themselves. In dry weather, cracks appear in the affected areas, and with high humidity, the stems rot and break. When the disease develops severely, the entire aboveground part plants. For prevention, it is necessary to observe the humidity regime in the greenhouse and avoid sudden temperature changes.

If possible, use calcined soil. And as a preventive measure, you can spray cucumbers in the greenhouse with Oxychom, Kuproxat or copper oxychloride. In case of infection, it is necessary to carefully remove the areas affected by the disease.

Why cucumber leaves turn yellow is often not so easy to understand, because there are many reasons and it seems that they all fit your case. But we have to do something, we don’t want to lose the harvest.

How to prevent yellowing of cucumber tops and what to do if the cucumber leaves have already begun to turn yellow? Let's find out now.

Why cucumber leaves turn yellow: 6 reasons

The first reason is trivial - some of the lower leaves inside the bed turn yellow and die from lack of light. This is not a cause for concern at all, it is normal.

As a rule, a cucumber bed is a real lush jungle; it is not surprising that light penetrates inside with difficulty and the lower old leaves do not have enough of it. In this case, just pick off the yellow leaves from time to time and enjoy the harvest. The second reason is a lack or excess of moisture.

In normal summers, it is recommended to water cucumbers generously two to three times a week, and in hot summers - every day, thoroughly soaking the soil. Otherwise, the roots of the cucumbers will begin to “climb” to the surface of the earth in search of moisture and may dry out.

This is a disaster for plants; both leaves and ovaries begin to turn yellow. Rainy weather is also not to the liking of cucumbers: the roots rot, rot forms on the stems, and as a result we see yellow leaves again. The third reason is fungal diseases.

Most often, fusarium, pythiosis and other fungal diseases are the cause of yellow leaves on cucumbers. First, rusty spots appear on the tops, then the leaves become completely covered in spots, dry out, and fall off.

Moreover, in the case of fusarium, the lashes become lethargic, like a rag, and do not respond to watering. If thirty-degree heat has given way to cold rains and lower night temperatures, hold on: fungi will not keep you waiting. The fourth reason is pests.

Whitefly or spider mites suck all the juices out of cucumber leaves As a result, the leaves turn yellow and die. In this case, the recommendations are obvious: good pest- dead pest.

You will have to either spray the garden bed with “poison” or resort to folk remedies. The fifth reason is a lack of nutrients. The most unlikely, but still common cause of yellowing cucumber leaves.

If the edges of cucumber leaves turn yellow and dry out, they may be lacking potassium or magnesium. Dark green veins against a yellow background may signal a deficiency of iron or manganese. Yellowing of the upper leaves occurs due to a lack of copper.

Feeding will help correct this situation. And the last reason for yellow leaves is old age. Over time, the cucumber leaf becomes coarser, ages, stops photosynthesis, turns yellow and dies. Most likely, by this time you have already eaten your fill of cucumbers, and the aging lashes do not bother you.

But if you want a fresh cucumber straight from the garden before the fall, there are ways to “extend the life” of cucumber vines, and we will talk about them later.

What to do if cucumber leaves turn yellow

The best treatment for everything in the world is prevention, and yellowing of cucumber leaves is no exception. It’s easier to prevent something like this from happening in your garden than to treat it later. Therefore: 1.

Try to maintain crop rotation. Do not plant cucumbers in the same place from year to year, do not plant them after zucchini or pumpkin, otherwise the likelihood of “catching” a fungal disease significantly increases.2. Water your cucumbers promptly and abundantly.

If you are on the site only on weekends, take the time to mulch the beds well with weeds or mown grass. A thick layer of mulch will prevent moisture from evaporating, and will also provide the cucumber roots with additional nutrition and warmth.3.

After sprouting in the 3-4 leaf stage (and then every 10 days), spray the cucumbers with the following composition: 20 grams of laundry soap, 1 liter of milk and 30 drops of iodine per 10 liters of water.5. Another option for preventive spraying: soak a loaf of bread in a bucket of water in the evening, knead the bread in the morning and add a small bottle of iodine.

Dilute one liter of this mixture in a bucket of water and process the cucumbers. If you repeat this procedure once every two weeks, you can keep the cucumbers green until autumn.6. In June, soak the cucumbers with a soda solution (1 tablespoon per 10 liters of water).

Then the onion peel is squeezed out, the broth is filtered and diluted in a ratio of 2:8 with water. Spray the leaves from above and below with this solution, and then spill the soil.8.

If you still can’t protect yourself and the leaves begin to turn yellow, try spraying the cucumbers with a solution of whey or kefir (2 liters per 10 liters of water). For better fruit set, you can add 150 grams of sugar to the solution.9.

When the leaves just begin to turn yellow, watering with a weak solution of potassium permanganate can help. 10. To prolong fruiting and rejuvenate aging cucumber leaves, apply foliar fertilizing with urea, while simultaneously adding humus under the roots.

Spraying rotted hay with an infusion does an excellent job of accomplishing the same task. To obtain the infusion, the hay is soaked in water (1:1) for two days. Spray cucumbers three times at weekly intervals.

11. To protect against pathogenic fungi and bacteria, use biological preparations (for example, trichodermin). They suppress harmful microorganisms, but are safe for humans and animals. We wish you success and big harvests!

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 reason 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 in the 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 for the root system of cucumber plants to develop deeply and not superficially. Regularity of watering is crucial: if you only miss watering the plants a few times, this will immediately affect the quality of future fruits. So, lack of moisture entails 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°C for a long time. The composition of the soil 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 boarding cucumber seedlings and after the harvest is harvested, the mandatory application of manure to the soil is carried out. 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 spots resembling a white coating are found on the leaves, gradually increasing in size, then this is a sign of infection. The leaf dries and turns yellow.

How to deal with this trouble? If you do not worry about measures to destroy powdery mildew, it will certainly make itself felt next season.

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. Dangerous fungal disease, causing 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, it is required complete replacement soil. In addition, you need to regularly change the variety of plants. Melon aphids.

Special preparations work well against these pests: 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 of high air and soil humidity, 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 appear on the lower leaves. Preparations to combat pernosporosis - Bordeaux mixture or copper chloride (for the first treatment), "Bravo", "Avixil" (for the second treatment after 7 days).

Lack of nutrients causes changes in the color and shape of cucumber leaves. But in order to figure out what is missing, or what was added in excess (this also happens), you need to decide how the leaves turn yellow:

• the entire leaf plate;

• along the edges;

• in the form of spots;

• the leaf loses its greenness between the veins, although they remain green.

As you can see, there are many options. You need to examine the cucumbers and try to determine the problem yourself. Otherwise, the crop may disappear, because with some symptoms the ovaries are shed. And losses begin with banal yellowing.

The second question is, if the cucumbers are pale green, what should you feed them with?

Supposed reasons for the loss of green color in cucumbers

Nitrogen is responsible for the accumulation of green pigment in plant leaves. But if the root system is weak, then it will not be able to absorb nutrients, even if they are in the soil. Therefore, the reason must be sought deeper.

Roots may not develop due to alkaline soil reaction. If lime was added to it, then phosphorus nutrition will be unavailable to the plants, since phosphorus itself has a high pH.

For complete decomposition, it needs acidic neighbors - nitrogen and potassium. With phosphorus starvation, the foliage turns yellow unevenly - yellow-brown spots appear, which dry out after a couple of days.

A chain reaction results: plants do not absorb phosphorus because it is not available to the roots. Due to a lack of phosphorus, nitrogen is not absorbed. You need to look first at the roots of the cucumbers.

If they turn yellow, then fertilizing with mineral mixtures will not help - most likely, the plants will die. If the root system white, then you can start with spraying with urea. This fertilizer is best absorbed through the leaves, so the effect will be quick.

If the lower leaves of cucumbers are light green, feed them only with nitrogen. Because the lack of nitrogenous substances begins to appear first on the old foliage, and then moves to the young tops - they also begin to turn yellow, dry out and die.

Important! With nitrogen starvation, there are other signs that you need to pay attention to - thin shoots of cucumbers, small leaves, fruits with pointed tips, few flowers and ovaries

Another important element nutrition of cucumbers during the fruiting period - potassium. If there is a small amount in the soil at the beginning of the fruiting period, the foliage may begin to turn yellow at the edges. Potassium starvation can be distinguished from nitrogen starvation only by the marginal “burn” of foliage. With nitrogen, the leaf suffers completely.

The yellow edge of the leaf subsequently dries out and dies.

Potassium starvation can also occur with a lack of phosphorus. Because of this close relationship, these elements contribute simultaneously. Potassium is absorbed faster by cucumbers, as it is needed for the formation of fruits and their ripening - it can be added during the growth of cucumbers. Phosphorus is consumed more slowly; dosages are usually sufficient for the entire fruiting period.

Lack of microelements - light leaves on cucumbers

Lightening of the foliage of cucumbers is primarily caused by a lack of copper. Appears at the tips of leaves. The process begins with the middle leaves - 4 – 5 below the top. Additional signs of copper deficiency:

• ovaries and flowers fall off;

• the plant becomes smaller and becomes dwarf.

Manganese, or rather its deficiency, also contributes to the appearance of chlorotic spots. The process is noticeable between the veins sheet plate cucumbers The veins remain green. The problem begins with the middle leaves.

With zinc deficiency, yellowing also spreads to the veins of cucumber leaves. The plant becomes spotted - there are shades of yellow, green and bronze.

A lack of iron in the soil causes uniform yellowing of young leaves. The process soon spreads to old foliage if measures are not taken and fertilizing is not applied.

Calcium is one of the most important microelements that plants feed for fruit ripening. Chlorosis due to calcium deficiency begins between the veins and along the edges. The veins themselves and the area adjacent to them remain green.

Magnesium is involved in the formation of chlorophyll, the green substance in cucumber leaves. A deficiency can weaken the plant and it will develop blossom end rot. Old leaves are the first to suffer - they lose color and become deformed.

If cucumbers have pale leaves, you need to decide what to feed. More often and easier, buy a solution of microelements and spray at intervals of a day or two until the balance is restored.

Soil care

With insufficient watering, the process of chlorophyll formation stops because the activity of beneficial microorganisms is suspended. And plants can absorb nitrogen only after it is absorbed by bacteria.

In this form nitrogen fertilizers available to cucumbers. What to feed is the second question. First you need to make sure that cucumbers get enough water, because they love moisture in both the soil and the air, because they come from tropical forests.

As soon as the water balance is normalized, cucumbers can independently restore the color of the leaves. Moreover, if fertilizing was applied regularly and there should be no shortage.

If the soil is cold - this happens when the temperature stays below 15 degrees for several days in a row, then the balance of nutrients is disturbed. The reason is that the activity of soil bacteria stops and plants do not receive the nitrogen they need.

The leaves of the cucumbers turn pale, but this phenomenon is temporary, so with the onset of warm weather everything is restored. To help plants in this situation, you can use complex fertilizers and carry out foliar spraying.

Fertilizers can be either purchased or mixed yourself. It is imperative that they be three-component if the situation arises in the first half of the growing season - in the spring, when temperature changes still occur.

If cucumbers have pale leaves, what to feed them with?

To balance the nutrients in the soil, you can use both organic and mineral fertilizers for cucumbers. There are a huge number of species of both. You don't need to use everything at once.

Video: Feeding cucumbers in the 4-5 leaf phase

Knowing the type of soil on the site and the needs of cucumbers, you can choose 2 - 3 types of mixtures and a solution of microelements to maintain the required amount of nutritional components.

Carefully! Plants can be poisoned by mineral nutrient mixtures if they have never been used for open ground. In this case, you need to start using fertilizers not according to the recommendations in the instructions, but in doses half as small as those indicated.

Nitrogen-potassium fertilizers

The most nutritious and safest are organic fertilizers for cucumbers, if the leaves are pale or have begun to gradually lose color. It is recommended to use overwintered manure or mature compost.

The problem is that not all gardeners live permanently in their dachas, but only visit them occasionally and cannot devote much time to growing plants. In this case, you can order manure from sellers or buy granulated chicken fertilizer in the store to feed the cucumbers a couple of times.

Manure, chicken droppings contain a large number of ammonia, potassium and trace elements. Soil bacteria are very fond of such fertilizers and quickly process them.

How to use fresh manure so as not to damage the roots of cucumbers.

• First you need to let it sit so that the excess ammonia disappears. To do this, fill a third of the bucket with fresh manure and fill it with water for a week. You need to stir the mixture periodically

• When it's brewed, dilute each liter with 10 liters of water

Water at the root approximately 1 liter for each cucumber bush.

Chicken manure is a very concentrated fertilizer containing large amounts of ammonia, which can burn root system in a matter of hours. Therefore, it is infused in the same way as mullein, but dilute a liter of solution in 20 liters of water.

Wood ash is a valuable organic fertilizer that can improve matters with a lack of potassium and phosphorus, if the cause of yellowing of the leaves is underdevelopment of the roots. Contains potassium, phosphorus and trace elements in total about 30 items. This is enough to restore the balance in the diet of cucumbers.

To prepare a solution of wood ash for irrigation, you need take 300 g of the substance and pour a bucket of water for 3 – 4 days. Then you can water it at the root. To prevent chlorosis, ash is applied to the soil in the fall. Wood ash is a valuable food for microorganisms. Enough dig up ash with soil once every 2 – 3 years.

Do not mix the ash solution with nitrogen fertilizers - they neutralize each other and become useless for cucumbers. When applying at the same time, you need to add ash at the root, and spray the leaves with urea.

Mineral mixtures

The simplest and fastest fertilizer is urea. This is a concentrated substance containing up to 46% nitrogen. It is sprayed on plants sick with fungus during nitrogen starvation. Urea must be diluted from calculating 50 - 100 g of substance per 10 liters of water. The amount of solution is sufficient for 200 square meters.

A feature of urea is large losses of the substance on alkaline or neutral soils. Therefore, if you have gone too far with lime, then it is better to apply it using the foliar method. It is also impossible to mix with alkaline substances - dolomite flour, ash. It is better to apply superphosphate with urea separately: phosphorus to the soil, urea to the leaves.

If the leaves have turned pale, you can use two or three-component commercial fertilizers for emergency feeding of cucumbers:

• azophos – two-component, contains nitrogen and phosphorus;

• diammophos – 2 nutritional components;

• nitrophoska is a three-component mixture containing nitrogen, potassium and phosphorus.

A feature of all mineral complex mixtures is the obligatory presence of either all three elements at the same time, or nitrogen and phosphorus. This confirms the version that the root system must develop first so that cucumbers have the opportunity to grow, fill and ripen.

Cucumbers are quite capricious to grow and require optimal conditions according to parameters such as temperature, humidity, amount of microelements in the soil. In addition, they are susceptible various diseases. The article outlines the main diseases of cucumbers in a greenhouse and their treatment, you will learn why the leaves turn pale and dry, the ovary disappears, how to understand that cucumbers have been attacked by aphids and spider mites, why cucumbers do not set.

Diseases of cucumbers in a greenhouse: main causes

The main reasons that contribute to diseases of cucumbers in a greenhouse include:

• soil contamination;
• low-quality contaminated seed material;

First of all, the plant is weakened due to violation of the rules of agricultural technology

• Not proper watering: excessive, leading to the development of putrefactive processes, or insufficient, weakening the plant;
• sudden temperature fluctuations;
• infection of plants by pests of various types;
• lack of mineral and organic substances in the soil, its depletion.

Cucumber leaves drying out

Diseases of cucumbers in a greenhouse, manifested by yellowing and drying out of the foliage, are usually associated with violations of the agrotechnical conditions for their cultivation.

Thus, often the root cause of the process of drying out of the lower tier of green leaves is insufficient watering.

Tip: water the cucumbers with warm water at least three times a week, generously under each bush.

In very hot summer conditions, cucumbers should be watered daily, or even twice a day - in the morning, spraying, and in the evening - watering abundantly.

Drying cucumber leaves

Also, cucumber leaves can dry out due to a lack of essential organic substances, trace elements and minerals in the soil.

Attention! It should be remembered that the soil in the greenhouse must be changed every two to three years, updating the top layer (about 25 cm) with a mixture of earth, sand, and peat to ensure good drainage and increase fertility.

Usually, cucumbers turn yellow due to a lack of nitrogen in the soil, caused by an oversaturation of potassium-phosphorus fertilizers or ash. But nitrogen fertilizers should be applied to the soil in doses, since excess nitrogen is just as destructive for cucumbers as its deficiency.

Aphids on cucumbers

Have you organized proper watering, fertilized the soil, but the cucumbers are withering? The plant may be infested with pests. Cucumbers in a greenhouse are often attacked by aphids, spider mite.

Checking this is quite simple - you need to turn the sheet over and carefully examine its back. Larvae and adult aphids (yellow, light and dark green, almost black) will immediately catch your eye. Cucumbers can become infected with aphids in late spring - early summer, after the leaves appear.

Aphids on cucumber leaves

Having occupied the plant, aphids begin to actively reproduce and feed on it. Lack of nutrients leads to a delay in the timing of flowering and ripening of fruits; they do not have time to gain the necessary mass before the end of the growth period. If there is a lack of food on one plant, aphids can move to another, thus infecting large plantings. Therefore, it is important to notice the infection in time and eliminate it.

Used to kill aphids traditional methods or use chemicals plant protection. The simplest treatment method is to wash the aphid-infested leaves with soap and water. It is also recommended to prepare an infusion of onion peels, garlic (500 g of finely grated cloves per 5 liters of water), leaves and stems of celandine, and then sprinkle the infected cucumbers.

Advice. If you need to get quick results or the cucumber plantations are large enough, it is recommended to use industrial insecticides.

Spider mites on cucumbers

Infection of cucumbers in a greenhouse with spider mites leads to plant disease, yellowing and drying of the green mass, and then wilting. Spider mites can be recognized by the small cobwebs that envelop the plant, creating a barrier to sunlight and oxygen, disrupting the process of photosynthesis. This pest is a carrier of a number of diseases. By feeding on sap from shoots and leaves, spider mites prevent further development of the crop and lead to withering and death of the plant.

The result of exposure to spider mites

It is necessary to get rid of spider mites immediately when the first signs of plant infestation are detected, otherwise you can destroy all the plantings. Experienced gardeners It is recommended to refrain from using chemicals, since they are quite toxic and in any case can have an adverse effect on the human body. It is better to use traditional methods.

To treat cucumbers against spider mites you should:

• tear off and burn infected leaves;
• wash the bush with soapy water;
• if the entire plant is shrouded in cobwebs, remove it from the garden bed and burn it;

If parts of the plant are severely affected, it is better to remove them immediately

• in cloudy weather, generously irrigate and water the cucumbers, cover them with film to increase humidity, which the mite cannot tolerate;
• Finely chop the garlic, place it near the infected bush and cover it all together with film or thick cloth for several hours. You can use a jar of turpentine in the same way.

Attention: cucumbers should be treated against spider mites several times every couple of days, since high temperature air (above 35°C), it reproduces at double the speed, the larvae hatch every 3 days.

Pale leaves on cucumbers

Diseases of cucumbers in a greenhouse can be caused by various factors, one of them is a lack of minerals in the soil. With a lack of nitrogen, cucumber leaves become pale, small, and curl. Fruits can lighten in the same way.

Plants lacking minerals

To correct the situation, you need to feed the plant with mullein at the rate of 1 liter of slurry per 10-liter bucket of water, water each bush at the root. In a similar way, you can use an infusion of weeds (“green cocktail”) diluted with water (take 1 part green to 5 parts water), urea (2 tablespoons per bucket of water) or ammonium nitrate (50 g per bucket of water).
Also, the plant may turn pale and wither due to powdery mildew.

Powdery mildew

Powdery mildew is a fungal disease of cucumbers in a greenhouse, manifests itself in the form of a whitish-gray coating on the leaves, the area of ​​which gradually increases. Infection with powdery mildew leads to drying out and death of the plant. Plants can become infected with fungal spores through soil in which nightshades or cucumbers have been grown for several periods. High humidity also contributes to the disease of cucumbers in the greenhouse.

Powdery mildew on cucumber leaves

To remove powdery mildew, it is recommended to cut off the infected foliage and irrigate the bush with a solution of liquid mullein (about 1 liter) mixed with 1 liter of urea. A solution of potassium permanganate is also effective (dissolve a few crystals on the tip of a knife in 10 liters of water until the mixture turns pinkish).

Downy mildew

At high humidity inside the greenhouse, sudden changes in temperature, improper watering with cool water, the leaves begin to wither and fall off - the plant is affected by peronospora or downy mildew. At the same time, the leaves turn yellow on top, and a grayish-purple coating appears on them below.

For treatment, it is recommended to organize proper watering, regular ventilation of the greenhouse, and add phosphorus-potassium fertilizers(sprinkle the ground with wood ash). Experienced gardeners treat plants with Bordeaux mixture: dilute about 100 g of copper sulfate and freshly slaked lime in a bucket of water. Treat cucumbers with this solution. The fruits can be eaten after a week.

Downy mildew

To prevent powdery mildew, you can spray the soil in the greenhouse with tansy decoction: pour 30 g of dried grass (or 300 g of fresh) into 10 liters of boiling water, leave for 24 hours, then boil for about 1.5 hours, cool and apply.

Who eats cucumber seedlings in the greenhouse

The main pests of cucumber seedlings in greenhouses are mole crickets, wood lice, click beetle larvae, cucumber gnats, thrips, and whiteflies.

Mole crickets and click beetle larvae damage the root system young plant, eating the roots of seedlings. This leads to curvature of the main shoot of the plant and its drying out. You should fight mole crickets by pouring a solution of ground black pepper (5 tablespoons per bucket of water) or vinegar (0.5 liters per bucket of water) into the burrows.

Plant damaged by beetles

Slugs (resemble a snail without a shell) eat the foliage, ovaries and young fruits of cucumbers, reducing productivity. Methods of controlling woodlice include removing them from the plant mechanically or using bait. In the evening, halves of potato tubers are laid out near the beds, in which small recesses are made. In the morning, slugs can hide in these tubers; they must be collected and taken out of the garden in the morning.

Why does the ovary of cucumbers dry out?

Are cucumbers blooming profusely but not setting? To ensure the ovaries of cucumbers in a greenhouse, you should remember several important rules:

• self-pollinating varieties of the first reproduction should be selected. In this case, you can be sure of receiving good harvest subject to agrotechnical cultivation standards;

Drying of the ovary of cucumbers

• fruits do not set if the temperature in the greenhouse at night drops below +15°C. The greenhouse should be heated;
• It is necessary to organize regular ventilation. Cucumbers do not set unless there are air vibrations or insects for pollination.

To obtain a good harvest of cucumbers in a greenhouse, it is important to ensure the prevention and timely treatment of their diseases.

Diseases of greenhouse cucumbers: video

Diseases of cucumbers in a greenhouse: photo