cucumbers
cucumbers are one of the most popular crops to grow. In greenhouse conditions, they feel great. The fruiting period of cucumbers in greenhouse cultivation is two months longer than that of those growing in open ground.
And the very amount of harvested fruits is about 25% more. And yet, even in greenhouse conditions, growing cucumbers can bring a number of unpleasant surprises. One of the main concerns of any gardener is yellowing and further falling off of the ovaries. cucumbers in a greenhouse.
Read also: Cultivation of cucumbers in open ground: planting seeds and caring for them | (Photo & Video) +Reviews
Description
Rice. 1 - Cucumber ovary
The death of the ovaries is a process, in fact, a natural one. Moreover, each variety has a certain percentage of ovaries that can die. It can be from 5% in especially large varieties to 20% in beam varieties.
However, if such a process becomes widespread, or when yellowing and subsequent wilting occur in a large number of ovaries at the same time, this is a serious reason for the gardener to think about the reasons for this phenomenon. And not just to think, but to take adequate measures, since in some cases such symptoms can have serious consequences.
Rice. 2 - Withering ovary of cucumber
Let us consider in more detail the main causes of yellowing of the ovaries and possible methods of dealing with this negative phenomenon.
Read also: Cucumbers: description of 29 varieties, main characteristics and gardener reviews about them | (Photo & Video) Containment Breach
Little light
Thermophilicity and light-loving cucumbers are well known. These plants react very negatively to the lack of light. Therefore, if it is planned to grow cucumbers in a greenhouse, then even at the stages of design and construction the greenhouse should be chosen in such a way that the cucumbers are well lit for the necessary part of the time (at least 12 hours a day).
In addition, often poor lighting is associated not only with the location of greenhouses, but also with a lot of greenery in the greenhouse itself. The reason for this can be both tightness of planting and excessive growth rate of the vegetative parts of the plant, or simply the use of too sprawling plant varieties.
Rice. 3 - Greenhouse with too much shading
That is why it is necessary to correctly select both the amount of planting material in the greenhouse, and the issues of varietal and hybrid compatibility of these or other varieties of cucumbers. For example, hybrids pollinated by bees traditionally have a small amount of foliage and can be planted at a density of up to 3 plants per square meter. m. Artificially pollinated or self-pollinated cucumbers can be planted, based on the calculation of 2-3 plants per 1 square. m.
But cucumbers that do not need pollination at all (parthenocarpic) have the most branched vegetative system and the largest leaves and should be planted with much less frequency - from 1 to 1.2 square meters per plant. m.
Wrong temperature
Most plants feel comfortable in a certain temperature range.It is undesirable to go beyond its limits, since the conditions of its maintenance will simply worsen in the plant, but irreversible processes may begin, leading to its death. But that's not all: plants have not only norms for the temperature range, but also the maximum daily temperature fluctuations.
Cucumbers are no exception in this regard. They feel comfortable in the range from +18°С to +35°С. The temperature difference during the day should not exceed 6°C.
Violation of temperature regimes adversely affects plants, which leads to the death of the ovaries. Properly maintaining the temperature inside the greenhouse is a rather complex task and requires the grower to either constantly control the temperature or use some kind of thermal control system. Naturally, the use of temperature control systems in greenhouses is a task that seems to many to be either too expensive or not worth it at all.
Rice. 4 - The temperature in the greenhouse when growing cucumbers should not exceed + 35 ° C
And, nevertheless, it is necessary to maintain temperatures at acceptable values for at least a few days at the time of fruit set and avoid large fluctuations.
The implementation of these actions depends on each situation separately and only general recommendations can be given here. In extremely cold climates, various heaters with temperature controllers or heat guns should be used.
Incorrect humidity
The closed space of the greenhouse, as well as the irregularity of ventilation, can lead to a significant increase in air humidity. By itself, it does not pose a serious danger until condensation appears directly on the leaves, stems and fruits of cucumbers.
Water droplets that appear on certain parts of the plant can not only cause sunburn, but also provoke the appearance of various diseases in cucumbers, primarily fungal ones.
For ovaries, this is doubly detrimental: firstly, the flower itself or the ovary may be damaged, and, secondly, a violation in the health of the plant can lead to the complete death of already formed ovaries.
Rice. 5 - Formation of condensate in the greenhouse at high humidity
Cucumbers require relatively high humidity (above 75%), however, it is not worth exceeding its values and bringing the air to a very obvious condensation of water vapor.
The greenhouse should be regularly ventilated and condensate located on the ceiling and walls should be removed.
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care issues
Irregular watering
The intensity of watering cucumbers depends on what stage the plant is at. During fruit set or fruiting, watering should be increased. A lack, or vice versa, an excess of moisture, can disrupt the processes in the formation of fruits and lead to yellowing and abscission of the ovaries.
In order for the plant to feel normal, watering should be carried out regularly, at intervals determined by the properties of the soil, temperature, degree of illumination of the greenhouse, and so on.. There is a very simple criterion for the need for watering - excessive dryness of the topsoil.
Rice. 6 - When the plant lacks moisture
After observing for several days cucumber seedlings or mature plants, it is easy to understand how to adjust the watering schedule. It is necessary to do this and continue to constantly ensure that the soil is constantly moistened.
Watering too intensively is also not worth it, since excess moisture leads to rotting of the roots and an increase in air humidity in the greenhouse. All these factors together also lead to yellowing and falling of the ovaries.
Feeding problems
Yellowing of the ovaries is also possible due to a violation in the supply of the plant with the necessary fertilizers and trace elements. Such violations include both deficiencies in the "diet" of the plant of certain substances, and their incorrect ratio.
Rice. 7 - Foliar feeding of young cucumbers
So, for example, a lack of nitrogen leads to the fact that the plant loses its pigmentation, becomes first white and then yellow, the leaves and fruits begin to curl. Excessive excess of nitrogen can generally lead to the absence of flowers, and to the appearance of ovaries. Parthenocarpic varieties of cucumbers have the greatest vulnerability from incorrectly selected dressings.
In order to avoid the death of the ovaries from a lack of fertilizer, you should use the following feeding scheme:
- First dressing - produced when the plant is planted in the ground. It uses urea at a concentration of 20 g per 10 liters of water. You can use mullein in a ratio of 1 to 20.
- Second top dressing - produced 2 weeks after the first. The same urea is used in the same doses. Sometimes, instead of it, niroammofoska is added at a concentration of 15 g per 10 liters.
- Third top dressing carried out during flowering. At this stage, the plant needs any potash fertilizer. It is advisable to use foliar top dressing in this case, a solution of 5 g of potash fertilizer in 2 liters of water.
- Fourth top dressing carried out after the appearance of the fruit. It is also foliar for this, 15 g of nitroammophoska are dissolved in 10 liters of water.
- Torture top dressing produced one week after the fourth. It is done under the root and consists of potash fertilizers; 5 g of potassium in any form dissolve in 10 liters of water.
Incorrect pollination
The plant should create conditions for pollination. Successful pollination is a guarantee of health and safety of the ovaries. Depending on the type of pollinator and method of pollination, appropriate actions should be taken.
If the plant is pollinated by insects, the greenhouse should be kept open throughout the daylight hours so that bees, wasps and other insects have unhindered access to the flowers of the plant. Sometimes, in order to lure pollinating insects, it is recommended to install a saucer with sugar syrup at the entrance to the greenhouse.
Rice. 8 - Artificial pollination of cucumbers
Its composition is as follows: sugar is mixed with water in a ratio of 1 to 2 and 1/20 of the yeast is added to the resulting syrup. The mixture is then brought to a boil and cooled. Sometimes, to give it a cucumber smell, male cucumber flowers are immersed in it.
It is also necessary at the planting stage to make sure that there are plants in the greenhouse with both male and female flowers.
You can also pollinate the plants by hand. In this case, either a freshly picked male flower is used, or a brush, with the help of which pollen from male flowers is transferred to female ones.
For self-pollinating plants, you just need to regularly ventilate the greenhouse room.
Other violations of agricultural technology
No less widespread are errors in the cultivation of cucumbers associated with incorrect tillage, or with an incorrect alternation of predecessor and successor plants. All of them lead to the fact that the nutrition of the plant will be insufficient. This will cause a lack of nutrients, which in turn will lead to the death of the ovaries.
It must be understood that the greenhouse is the same garden, only protected from the weather. And all the rules applicable to the garden should be applied to the greenhouse. One such rule is to maintain a correct crop rotation. One of the most common reasons for a plant to drop the ovaries is to cultivate cucumbers in the same place for several years.
Rice. 9 - Too dry soil, partially covered with a crust. Need loosening
Detailed practice not only depletes the soil, but also leads to the accumulation of pathogens and pests in it, "specializing" exclusively on cucumbers.On the other hand, greenhouses are specially created to grow some of the same crops year after year.
The way out of this situation may be the use of green manure. For example, plant some legume or winter wheat after cucumbers.
Another frequent violation of the rules of agricultural technology is the use of obviously poor soils, without any kind of fertilizer whatsoever. Or, the use of exclusively mineral fertilizers to increase the fertility of a particular area.
You should not rely on mineral fertilizers alone. At least once a year (usually at the beginning of the season), the soil in the greenhouse should be fertilized with humus or compost. You can use solutions of mullein or chicken manure. As a last resort, use ordinary wood ash. Moreover, excellent results are obtained by a combination of this and the previous method: the use of organic fertilizers and green manure.
Another common cause of wilting and yellowing of the ovaries are overgrown fruits. You should not grow giant cucumbers in a greenhouse, larger than those indicated in the description of the variety. The grown fruits, when they are already fully formed, greatly inhibit growth and the emergence of new ovaries. Therefore, ripe fruits should be harvested as soon as they reach the required size.
Well do not forget about the elementary rules for caring for plants - the obligatory loosening of the soil after watering and weeding. After all, even in greenhouses, unwanted guests can start.
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Many plants
One of the most unpleasant reasons, because it is not always obvious, and in addition, its elimination brings the owner a lot of unpleasant moments. After all, not everyone wants to get rid of beautiful, self-grown, giant pets.
Excessively dense planting of cucumbers, especially in several rows, is dangerous primarily due to a violation of the lighting and ventilation regime. And this, like a chain reaction, leads to the following unpleasant consequences: poor nutrition, poor pollination and excessive waterlogging. This is followed by a weakening of the immune system and an attack by a pathogen or some kind of bug.
Rice. 10 - Too close planting of cucumbers in the beds
Proper planting of plants at the stage will help to avoid this. planting them in a greenhouse. Recommended areas have been given previously. Excess seedlings can be "hold" for some time, so that with the advent of warmer weather, they can be planted in open ground. So that it does not grow very quickly, it is either placed in colder conditions, or watering is reduced to a minimum.
Naturally, when the realization of too close planting comes at the stage of formation of the ovaries, it will be almost impossible to do anything except how to remove the extra plants. And no matter how sorry it may be, you will have to sacrifice the less strong and tall to get a good harvest.
Many ovaries
The plant has to expend its energy to maintain them all. Naturally, this situation does not suit the gardener, since the plant simply does not have enough strength to form so many fruits.
Rice. 11 - An excessively large number of ovaries on a bush
The solution to the problem is quite trivial - all extra ovaries that have formed either in uncomfortable places, or where they should not have been at all, should be removed. Usually, this is done before the formation of the ovaries themselves, at the time when the flowers appear.
Read also: Growing seedlings at home: tomatoes, cucumbers, peppers, eggplants, cabbage, strawberries and even petunias. All the subtleties of this issue
biological factor
Diseases
The ovaries may turn yellow and fall off if the plant is ill with some kind of disease. Usually, if at the same time not only the ovaries, but also the leaves turn yellow and fall, the cause of this is bacteriosis.
Bacteriosis is one of the most common diseases of cucumbers, significantly reducing the yield.
Symptoms of the disease are as follows:
- at first, small spots or droplets of liquid appear on the leaves;
- over time, they turn black and dry, while the tissue around the site of the lesion begins to dry out;
- after 2-3 days, the lesion spreads to the entire leaf, it turns yellow, shrivels and falls off.
Rice. 12 - Bacteriosis. Most common disease
The fight against bacteriosis consists of two stages: the removal of damaged parts of the plant and the preventive treatment of the remaining, unaffected parts. After removing the affected leaves, ovaries and flowers, the cut sites must be treated with a 0.2% solution of potassium permanganate.
The remaining parts of the plant and its neighbors should be sprayed with a mixture of the following composition:
- Bordeaux mixture - 100 g;
- copper chloride - 40 g.
- water - 10 l.
Another, no less dangerous disease of cucumbers, leading to yellowing of the ovaries, is powdery mildew.. This fungal disease in all plants has the same symptoms, consisting in the appearance of small "cobwebs" distributed over some part of the plant. Over time, the cobwebs turn black, and ulcers appear in their place.
Rice. 13 - Powdery mildew on cucumber leaves
Usually, when powdery mildew is affected, like any fungal disease, the plant stops flowering and fruiting. If the disease is in an early phase, or it cannot completely overcome the protective barriers of the plant, then the effect of the disease will be, although not so detrimental, but still unpleasant. The fruits will shrink significantly, they will become more faded and twisted.
Pests
The pest can also affect the formation of ovaries. This is not surprising, because, feeding on the juices of plants, they disrupt its nutrition and natural metabolic processes. In this case, as in the case of diseases, not only yellowing or wilting of the ovaries is possible, but also a complete cessation of fruiting.
Rice. 14 - Typical pests on seedlings - thrips or aphids
Most often, cucumbers are attacked by aphids.. Usually, aphids appear on cucumbers at the end of June. These are small insects, up to 1.5 mm long, usually green or yellow. Usually, they appear together with ants with which they live in symbiosis.
Despite their small size, due to their numbers, aphids are capable of destroying any plant in the shortest possible time. Therefore, do not put off the destruction of these pests indefinitely. The best remedy for aphids are insecticides of the acaricidal type. As a folk remedy, you can use a solution of soap and copper sulfate in water (10-30 g of copper sulfate are dissolved in 1 liter of water and 20 g of liquid soap are added). This mixture is applied directly to the areas of the plant affected by aphids.
Another common cucumber pest is the spider mite. His activity also has a significant impact on fruiting. The tick is a small bug about 1 mm in size, red or yellow.
Rice. 15 - Spider mite
Against this pest, acaricides should also be used (for example, Mayt, Ortus and others).
Read also: 56 The best productive varieties of cucumbers for greenhouses: description and photo | +Reviews Conclusion
Yellowing of the ovaries of young cucumbers is a widespread problem, and its cause can be a variety of phenomena. Perhaps this reason is very simple and easily eliminated, and perhaps there are several of them and each requires a comprehensive solution.
In any case, all possible options for the occurrence of yellowed ovaries should be considered - from non-compliance with growing conditions to the possibility of pest invasion, find the one that is decisive and eliminate it.
VIDEO: Cucumber ovaries turn yellow 10 Reasons Why and what to do
VIDEO: Cucumber ovaries turn yellow 10 Reasons Why and what to do
We save the yellowing ovaries of cucumbers in the greenhouse: a description of the causes of the problem, methods of combating and preventing this deviation (Photo & Video) + Reviews
We don’t have such problems at all after the first year we started growing cucumbers in greenhouse conditions. We have installed temperature and humidity sensors around the entire perimeter, keeping them within +30 degrees and 65% humidity. We process during flowering with a solution of potassium permanganate. The soil is fed with any fertilizers. This procedure completely eliminates problems with flowering and ovary.