Why cucumbers can turn yellow in a greenhouse

Many summer residents who grow cucumbers in the greenhouse face the problem of yellowing and drying leaves. In this case, you need to understand why the cucumbers turn yellow in the greenhouse. There can be many reasons for this: lack of moisture in the soil, lack of sunlight or various diseases and pests.

Causes of yellowing of cucumbers in the greenhouse

If there is a threat of crop loss, you need to solve the problem immediately until all the plantings have turned yellow. Yellowing the leaves is a signal, calling the plant for help. don’t worry if the lower leaves of the plants turn yellow. Basically, the yellow lower leaves are simply removed, without harm to the plant. You need to deal with other problems.

Temperature drops

Why turn yellow cucumbers in a greenhouse? Cucumbers like heat and moisture and can not tolerate sudden changes in temperature. In an effort to get an early harvest, gardeners try to plant seedlings early, using greenhouses for this. But without heating during frosts, the temperature at night there is only a few degrees higher than on the street. Low temperatures can cause plants to freeze. Why do cucumbers still turn yellow in the greenhouse?If in the afternoon under the sun, the greenhouse heats up very much and the plants there are so hot that it is necessary to open the windows and doors for ventilation, then the embryos dry out and the edges of the leaves turn yellow and wilt over time.

If the cucumbers are steamed, then they stand as boiled and later fall off in a greenhouse. It turns out a large temperature difference and the plants feel uncomfortable. Leaves turn yellow, plants stop growing, and may even die. To protect against night frosts in the greenhouse, gardeners use additional shelters from film or other covering materials. You can put five-liter water bottles in the greenhouse. During the day they will heat up, and at night they will begin to gradually give off heat, maintaining the optimum temperature. For cucumbers, the ideal temperature is 22-26 degrees. When the temperature rises above 40 degrees or below -14, nutrition does not enter the roots, and the plants do not develop.

Lack of nutrition

What to do if the embryos wither when properly and proper care? What causes ovaries or finished fruits? In this case, the problem may be in the insufficient nutrition of your landings. First of all, you should properly prepare the soil for planting. Without the required amount of necessary microelements, there will be no crop and the pupals in the greenhouse turn yellow and dry.

Nitrogen, magnesium and potassium should be contained in the soil in sufficient quantities.The yellowness of leaves when grown in a greenhouse may indicate a lack of necessary substances in the ground. This is usually due to a nitrogen deficiency. First, the leaves brighten, and then turn yellow, curl and dry. Subsequently, the whips begin to turn yellow. About the lack of nitrogen, you can also notice the fruit in the form of a hook.

Fertilizing the soil and cucumbers

• In the autumn, when digging the soil, humus is introduced into the soil (2 -3 buckets per 1 sq. M). You can make it in the spring before planting seedlings.
• Before planting, seedlings are fed with fertilizers and sprayed with water with dissolved trace elements.
• During the summer, cucumbers are watered with chicken droppings. Herbal infusion with nettle helps well. Young nettles are finely chopped, put in a container and poured with water. Hold for several days, constantly stirring. The solution is used for watering, adding 0.5 l per bucket of water.
• Plants can be fed with urea, in a dosage according to the instructions on the package.
• To provide potassium, you can use tree resin or buy the right drugs.

Feeding the soil properly, you take care of the harvest.

Moisture deficiency

Cucumbers love moisture and need not only in good watering, but also in optimal humidity. If you notice that the cucumbers fade, and then yellow spots fall on the leaves between them, then this is a sure sign of moisture deficiency.Watering plantings can only be done at ambient temperature. You can not pour cold water. From cold moisture, or lack thereof, the leaves may turn yellow, after which it is quite difficult to restore nutrition in the leaves of the plant.

During fruiting, watering increases. Before irrigation, water must first be left to stand for 3-4 days. The soil must be moist so that the roots of the plants develop well. Plant health and productivity depend on this. Please note that excessive watering is also harmful. It can cause fungal diseases. Watering should be near the root in a few centimeters, trying not to fall on the leaves.

Bad pollination

In greenhouses they try to plant self-pollinating varieties, but they also need pollination. Without this plentiful harvest there will be no. It is necessary to find out if the ovary is not pollinated enough, then it can turn yellow. This happens mainly without airing the greenhouse, and when there is no access for insects to the greenhouse.

To correct the situation, spraying the bushes with a solution of boric acid or special preparations for ovary will help.

To attract bees, plants are sprayed with sweet water (with sugar or honey) or boron-magnesium fertilizers, which increase the release of nectar on the flowers.You can plant borago and hyssop in the greenhouse. Insects love these honey plants and make their way inside, pollinating seedlings. By tearing off a male flower, you can pollinate several female buds yourself.

Inadequate care

If the seeds of cucumbers turn yellow in the greenhouse, what should I do? With insufficient care, the ovaries of cucumbers in the greenhouse and their fruits also often turn yellow. Many gardeners love cucumbers for their taste and easy care, but you must follow the watering, lighting and feeding schedule. Without proper care, it is impossible to grow a strong and healthy crop. In greenhouse conditions, cucumbers develop rapidly and can form many ovaries at once. This overloads the bush, and its leaves turn yellow.

If the ovaries are more than the norm, then the yellowing of young cucumbers that are lacking in nutrients is typical.

In this case , you need to pinch the shoots on time. On one bush leave no more than 25 ovaries. This makes it possible for cucumbers to form and mature. If gardeners leave more ovaries, they will get ugly yellow fruits. Watering during the day in the heat and moisture on the leaves can cause a sunburn. Therefore, watering plantings should only be in the morning or evening. Care must be taken for landings. If the roots are damaged when loosening or weeding, the leaves will turn yellow.

Diseases

If the cucumbers in the greenhouse turn yellow for no apparent reason and all the conditions for their growth are met, then it is possible that your plantings have been affected by diseases or pests. There are a lot of diseases that seedlings suffer, and in order to properly prescribe treatment, you need to know the signs of the disease. Landings can be affected by harmful insects and infections. Fungal diseases include:

• Root rot. Leaves of plants may turn yellow in case of root rot disease. Symptoms manifest in any phase of development. Root rot develops with sudden changes in temperature during the day and when watering with cold water. First, weak plants become ill. Gradually through the ground, the disease gets to other bushes. For prevention, the soil in the greenhouse is treated 2 times per season with Previkur.
• Peronosporosis. This is the name of the disease, known as downy mildew. It is provoked by an abundant ovary, it can appear with thickened plantings and if there are weeds between them. Powdery mildew also appears with abundant humidity in the air and in the soil. The extra ovary is torn off, removing small and weak, leaving only more active and tall. The first signs of the disease: yellow and light spots on the leaves and between them. Gradually, the spots become oily and brown. A gray coating appears at the bottom of the sheet. A plant affected by this disease dies very quickly.
• Powdery mildew is a fungal disease that blocks plant photosynthesis.Such a disease is very common, often affecting cultivated plants. First, small light spots form on the leaves. Gradually, the spots increase and cover the entire surface of the plant. Leaves are covered with white or red coating, turn yellow, dry and fall off. In the open ground, the disease acts on plantings equally. If you do not take action, you can lose the entire crop. Fight with powdery mildew fungicides. For disease prevention, varieties resistant to the disease are selected, the greenhouses are potted with potassium permanganate and green manure is planted.
• Fusarium is a dangerous and complex disease. Fusarium threatens with crop loss. Plantings sprout well and grow quickly, but when the ovary appears, the leaves begin to turn yellow, the lashes dry. The fungus that caused the disease prevents nutrients from entering the plant. To combat Fusarium, greenhouse varieties are regularly changed. Replace the affected soil and carry out serious processing of the greenhouse.
• With excessive watering, bacteriosis appears. The ovary turns yellow and dries, the resulting fruit is covered with plaque, growths and ulcers. In the early stages of the disease, you can fight it with a Bordeaux mixture. She quickly stops the development of the disease. Watering is done more moderately so that the soil is moist, but without excess.
• Cucumbers can become ill with excessive fertilizer. Feeding should be done no more than 3 times per season.The first time after the appearance of the first three leaves, the second time during flowering, the third time after the onset of fruiting.
• Viral diseases. If, in compliance with all agricultural techniques and the recommendations of specialists in care, feeding and watering, deformation and yellowing of the leaves occurs, this may indicate the appearance of a virus. So that plantings are not bad, you need to detect a viral disease as soon as possible. It is impossible to fight the virus.

Harmful insects

If insects make their way into the greenhouse, they can damage your plantings. When cucumbers turn yellow in a greenhouse when attacked by pests, what should I do?

• Melon aphid. This insect settles on the leaves on the lower side and between them and sucks the juice from the plant. Aphids can be dangerous for planting throughout the growing season.
• Spider mite. A mite cobwebs the inside of the leaves. They turn white or turn yellow and dry. Against the pest, drugs are used: neoron, phytoverm, actellic and others. Without their use, plants can die.
• Greenhouse whitefly. This harmful insect goes on planting with weeds. For prevention and pest control, weeds are removed on time, all openings in windows and doors are closed. Small nets are put on the air vents. The soil is fertilized with peat and sawdust. Set insect traps.

If you correctly find out why the ovary of cucumbers turns yellow in the greenhouse, many problems can be avoided in the future. Follow all the rules for growing crops, give them moisture, top dressing, light and heat as normal , without flaw and excess.