In greenhouse conditions, cucumbers are often affected by rot, and gardeners lose a significant part of the crop. Consider what types of rot are most often found in greenhouses, the reasons for their appearance and how to deal with these problems.
A kind of rot
In a confined space, various types of rot may appear in cucumbers.
White rot (sclerotiniosis)
The causative agent of this type of disease is a fungus that enters the plant from the soil. In a favorable humid environment, its white mycelium begins to grow and affect other crops growing nearby. 
The lesion site is first covered with a whitish coating, becomes watery. Over time, the mycelium blackens. The disease progresses quickly and the plant dies.
Did you know? The name of the cucumber comes from the Greek "aguros", which means "immature", because the fruits go to food, not reaching maturity, — Zelentsy.
Gray rot
It is characterized by the appearance of a gray coating on the leaves and fruits. It develops with high humidity at low temperatures. Usually affects the plant through various injuries. It can penetrate the flower pestle - in this case, the embryos rot. The disease may appear in the internodes or affect the fetus. At cucumbers, the tips begin to rot where the flower mounts are located.
Stem and root rot (Fusarium)
When the roots of cucumbers rot, the plants turn yellow and fall leaves, flowers, ovaries. The bush gradually withers and dies. Fusarium most clearly betrays itself below the stem - it rots, turns brown and thins.
With causeless wilting of foliage, a check for fusarium should be done. To do this, make a cut on the stem or leaf - if this rot is damaged, their center will be brown. The plant in this case is difficult to save.
Ovary rot
It starts with yellowing of the leaves, and then the ovaries and other parts of the plant begin to rot. The reasons for this phenomenon can be different - high humidity, watering with cold water, temperature difference, abuse of fertilizers.
Olive or brown spotting (cladosporiosis)
Olive spots appear on the plant, which eventually turn into brown sores. Mostly the fruit is affected: an olive coating appears on them, droplets protrude, which then harden. Small cucumbers bend during infection and do not grow. Under adverse conditions, the disease can spread to other parts of the plant - in this case, the whips and leaves begin to rot, and deep brown spots are observed on them.
Causes of Rot
The factors that caused the decay of cucumbers can be different. Most often, various diseases in this crop in the greenhouse arise due to increased humidity and improper care. Also, their appearance can provoke pests. Before taking any action, you need to find out why the rot appeared.
Did you know? The ancient Greek doctor Dioscorides recommended cucumbers for therapeutic nutrition. The famous medieval healer Avicenna later wrote about their usefulness.
Pests
Small parasites can settle on cucumbers and deplete the plant, making it susceptible to diseases, including rot.
Aphid
Cucumbers in a greenhouse are usually affected by the gourd variety of this pest. It has small dimensions (up to 2 mm) and green or black color.
To combat it, folk remedies are suitable:
- Ash solution. 0.5 l of ash and 50 g of laundry soap are dissolved in a bucket of water.
- Garlic solution. Insist day 100 g of crushed cloves in a bucket of water.
- Dandelion infusion. Pour 0.5 kg of chopped dandelions 3 liters of water and insist 3 hours.
Whitefly
This pest is a very small butterfly measuring 1.5 mm. She and her larvae feed on plant sap, damaging leaves and causing a soot fungus at the site of the lesion. This pest can simply be washed off with water, but a soap solution is best. After such a water procedure in the greenhouse, the soil is loosened no deeper than 2 cm and sprinkled with peat.
In the initial stages, you can use adhesive tapes and spraying with garlic solution. In case of severe lesions, you should use the chemicals "Aktara", "Detis", "Confidor".
Other diseases
Diseases also weaken plants, causing rot.
Powdery mildew
Ectoparasitic fungi cause this disease. Due to their vital functions, the plant becomes as if sprinkled with flour. The disease begins with leaves, and then spreads to stems and greenery.
Since the fruits can not be harvested after chemical spraying, it is best to use folk remedies during fruiting:Did you know? There are many varieties of the plants in question that are resistant to powdery mildew and many other diseases. It is better to focus on varieties such as Phoenix, Swallow, Pasamonte, Oktopus, Pasadena, Nightingale, Masha.
- whey solution (1:10);
- soap or soda-soap solution (50 g of soap and soda ash per 10 l of water);
- mullein infusion diluted with water 1:10.
Of the chemicals you can use copper preparations (Bordeaux liquid, chlorine), Topaz, Tiovit Jet.Black mold
This disease is also called soot fungus or black rot. This fungal disease often occurs against the background of the defeat of cucumbers by whiteflies, at temperature extremes, in varieties that often pinch and trim. Against it, treatments with copper preparations are effective (1% Bordeaux liquid or 0.5% copper chloride): two sprayings with an interval of 10 days are enough.
Cucumber Care Disorders in the Greenhouse
Cucumbers in a greenhouse often rot for the following reasons:
- excessive waterlogging;
- watering with cold water;
- the absence of loosening of the soil, as well as the presence of a large amount of weed grass around the bushes;
- high humidity, provoking the development of fungi and decay;
- too cool temperatures, sudden changes, drafts;
- thickening of landings.
Methods of struggle
Consider what you need to do when revealing signs of decay on cucumbers:
- Reduce watering to the required minimum. The first few days are better not to water at all.
- Make airing. Try to achieve the optimum temperature.
- Remove rotted areas of plants, as well as dig up and dispose of (burn) heavily rotten specimens. The place of slices is treated with a solution of manganese, sprinkled with ash or powder from equal parts of chalk and copper sulphate.
In addition, you should examine the plants for signs of damage by insect pests or other diseases and take appropriate measures.Important! Before chemical spraying, fruit is collected.
Against the appearance of fungal diseases that cause the process of rot of various kinds, alternative methods can also be used. For this purpose, a solution of wood ash is used. At the same time, this treatment of cucumber bushes is foliar top dressing and well strengthens the plant.
To prepare the solution:
- 300 g of wood ash is poured with water and boiled;
- then bred in a 10 liter bucket of water and add 50 g of chopped laundry soap for better adhesion to the bushes.
Such a solution is treated 2-3 times in 7 days: this tool is more beneficial for plants than chemical preparations. For preventive purposes, they can process cucumber bushes every 7-10 days.
Preventive measures
Any problem is better to prevent than to fix later. So that cucumbers do not appear rot, the following preventive measures should be taken:
- Observe crop rotation. Cucumbers should not be planted in areas where the predecessors were squash, parsley, celery, squash, and pumpkin. After growing on a plot of cucumbers again in the same plot, the culture can be planted only after 3 years. Good predecessors are cabbage and tomatoes.
- Observe the planting of cucumbers according to the recommended schemes. Bushes should not obscure each other.
- Perform a regular inspection to identify the first signs of fungal diseases.
- Maintain the recommended microclimate in the greenhouse. Humidity should be 85–90%, and soil - 80–85%. The optimum temperature regime is +21 ... + 24 ° С. It should be noted that considering the culture is thermophilic and does not tolerate a decrease in temperature to + 17 ° C - in this case, the greenhouse must be heated.
- Dress seeds before planting.
- Carry out regular loosening of the soil and removal of weeds in the area with plantings.
- After a complete harvest, disinfect the greenhouse, soil, the entire tool, and dig the soil for the winter.
- Perform preventive spraying. For this purpose, you can use chemical ("Fitosporin") or folk remedies (a solution of ash or soda, serum, nettle infusion). Spraying for prevention is carried out every 10-14 days.
- To carry out proper watering - to prevent stagnation of water on the site and waterlogging. It is good to use a drip system for watering.
Important! Plants should be watered with settled non-cold water. At the same time, watering must be carried out under the root, since falling drops of water on the leaves can cause burns to the plant.
Useful tips gardeners
Gardeners give the following helpful tips on preventing the decay process in cucumbers:
- To acquire high-quality seed material for planting.
- To maintain crop rotation, use several greenhouses to alternate planting of different plant crops. You can also purchase a portable greenhouse.
- Perform preventive spraying against fungal diseases.
- Ventilate the greenhouse.
- Avoid landing sites where groundwater is close to ground level.
- Feed regularly using organic fertilizers to create good microflora. Especially good against the appearance of the fungus is the introduction of wood ash into the soil.
If rot is found on the cucumbers, it is necessary to remove and process the diseased parts, spray it, determine and eliminate the cause of their occurrence. A set of preventive measures should also be taken.
