Why do cucumber leaves turn yellow in a greenhouse and what to do
Quite a few growers grow cucumbers in a polycarbonate greenhouse. However, many of them are faced with the problem that the cucumber leaves turn yellow. Before processing cucumbers, you need to determine why the leaves of cucumbers in the greenhouse turn yellow and watch a video that describes how to solve this problem. This is the only way to get rid of yellowed foliage and protect the plant.
Causes of yellowing
There are various reasons for the yellowing of leaves in cucumbers that are grown in greenhouse conditions. It is recommended that you familiarize yourself with them in advance in order to better understand how to deal with yellow leaves in the future.
Improper watering
Quite often, the leaves on the bushes turn yellow in the greenhouse due to improper watering. It's no secret that cucumbers are moisture-loving vegetables, but that doesn't mean they need to be watered very often. Particular attention should be paid to watering before fruiting. During this period, soil moisture should not be too high. It is because of the large amount of moisture that yellowing of the leaves can appear.
Another reason why the edges of the leaves turn yellow is watering with too cold water. If the temperature of the liquid is below room temperature, the leaves of the cucumber seedlings will begin to dry out.
A considerable number of vegetable growers grow cucumbers in the open field. In this case, it is necessary to pour water under the stem. Spraying the bushes in the sun can cause leaf burns. Cucumber seedlings should be watered early in the morning or evening so that there is no sun.
Bad light
Sometimes leaves turn yellow at the edges due to the fact that they are grown in rooms with insufficient light. Poor lighting not only leads to the fact that the leaves dry out, but also negatively affects the overall growth and development of the bushes.
It is recommended to plant cucumbers according to a special scheme, with the help of which the plants will not shade each other. So that the leaves do not turn yellow, you need to plant the bushes at a distance of at least 80 cm.
There are times when the leaves of seedlings turn yellow at the edges due to the large amount of light. Most often this happens in the summer, when the sun can not only warm the plant, but also burn it.
Unstable temperature
Not a single gardener is immune from sudden temperature changes. That is why cucumber leaves turn yellow and dry due to unstable temperature conditions. Even the greenhouse is not protected from such a problem, since due to night frosts, the temperature in the greenhouse can drop sharply.
To eliminate yellow leaves, it is necessary to take care of additional protection of the cucumbers at night. For example, they can be covered with special materials such as spunbond or agrotex.
Also, in cucumbers in the greenhouse, the edges of the leaves turn yellow due to the low temperature of the soil. It is recommended to grow bushes in soil that is warmed up to 20-25 degrees. At lower rates, the probability of drying the leaves increases several times.
Soil composition
Problems in cucumber leaves can appear due to the poor quality of the soil in which they are grown. When growing a cucumber, it is recommended to use moist and loose soil that allows water to pass through well. It is also worth taking care of the nutrients that many plants need. If their number is not balanced, then the leaves may become covered with yellowish spots.
Most often, an imbalance of minerals appears due to very frequent watering, which can wash out all important components from the soil.
Poor pollination
Another reason why the leaves can start to turn yellow is poor pollination. This problem is most common in plants that are grown in greenhouse conditions. To prevent the leaves from drying out, you need to periodically ventilate the greenhouse. This will allow insects to enter and pollinate the bushes. Also, for the formation of ovaries, you can use a tool such as Ovary or Bud.
Diseases
Sometimes yellow leaves appear on cucumber bushes due to various diseases. Most often, this vegetable suffers from bacteriosis, tobacco mosaic, ascochitis or peronosporosis. So that these diseases did not harm the cucumbers, it is necessary to engage in their prevention. For this, all plants should be pre-treated with special biological preparations that are absolutely harmless to animals and humans.
If the plant has already become infected and its lower leaves turn yellow, then the yellowed foliage is treated with a Bordeaux mixture. Bushes affected by bacteriosis or mosaic are not treated and therefore must be immediately disposed of.
Pests
Quite often, mites and other insects are the reason why cucumbers turn yellow. During the cultivation of cucumbers, it is recommended to take preventive measures that would protect the bushes from certain pests. To do this, you need to regularly process the plants with Funafon, Aktellik and Aktara.
Ways to fight
Having decided why the cucumber leaves turn yellow, you need to familiarize yourself with what methods are used to combat such a problem. This is the only way to find out what to do if the cucumber leaves in the greenhouse turn yellow. Various drugs are used to combat yellow leaves.
Aktara
This tool belongs to the group of neonicotinoids that are used to combat many pests. Therefore, it is recommended to use it if the plant has turned yellow due to pests.
Aktara is applied immediately after the first insects appear on the bushes. To do this, you need to prepare a working solution consisting of a liter of water and 20-30 ml of the drug. It is recommended to use the mixture in the evening and in the morning, when there is still no strong wind and sun outside. In windy weather, you should not use the drug so that it does not accidentally get on other plants.
The tool is very effective, since literally half an hour after using it, the insects stop feeding and begin to gradually die.
Magic capsule
If the leaves turn yellow due to decay products that have accumulated in the soil, then you should use the Magic Capsule. With its help, you can restore the ecosystem of the soil and clean it of various toxic elements. The preparation contains a large amount of nitrogen, which can accelerate the growth of bushes several times.Also, this tool is often used to treat weak and thin seedlings.
To prepare the solution, one capsule is diluted in 40-50 liters of water. In this case, the prepared mixture should be slightly infused. You need to water the bushes with liquid 2-3 times a week until the soil ecosystem is fully restored.
Clonex
If the edge of the leaves begins to turn yellow, you should use Clonex. With its help, you can not only protect the bushes from diseases and pests, but also strengthen the tips of the leaves. All this is possible due to the fact that the preparation contains quite a lot of vitamins and other useful components. You need to use the drug once a week.
Glyocladin
Glyocladin is used if cucumbers turn yellow due to fungal infections. It was released specifically to combat fungal pathogens on cucumbers and other plants. To prepare a working mixture, dissolve one tablet in a liter of water. The resulting solution is added under each bush that needs processing.
Maxim
To protect cucumbers from diseases and insects, you can use the fungicide Maxim. This drug is one of the most effective means in the fight against late blight, rhizoctonia and other diseases that may be accompanied by yellowing of the leaves in cucumbers. This fungicide is versatile, as it can be used to treat almost all plants.
Before using it, you must prepare a working mixture. For this, 4 ml of the drug is mixed with two liters of water, after which the liquid is infused for 30-40 minutes. The mixture can then be used to spray the bushes.
Folk remedies
Also, to combat yellowing of foliage, many people use various folk remedies.
Pepper
Many folk remedies are made from a variety of vegetables. In this case, the main ingredient for preparing the mixture is capsicum. 40 g of vegetable and 150 g of tobacco dust are mixed with a bucket of boiled water. Then the liquid is infused and filtered for 12 hours. After that, wood ash with liquid soap is added to it. The resulting mixture is very effective against mites or aphids.
Bread loaf
Some vegetable growers even use a loaf of bread to combat yellow leaves. It can be used to make a mixture that will help get rid of fungal infections. To prepare the solution, a loaf of gray bread needs to be soaked in 10 liters of water for a day. In the morning, a little iodine is added to the container with liquid. The mixture is thoroughly mixed and distributed among liter cans. Before spraying, one can of liquid must be added to a bucket of water, mixed and used to treat bushes.
Milk serum
This mixture is very effective in combating fungal diseases that can harm the leaves of cucumbers... It is recommended to use it immediately after the first signs of the disease appear. To prepare a working solution, add 2-4 liters of milk whey to 10 liters of water. All this is thoroughly mixed and infused for half an hour. Then 100 g of sugar is poured into the liquid, which is needed to improve the formation of new ovaries.
Conclusion
Many do not know what to do when the leaves turn yellow on the cucumbers in the greenhouse. To do this, you need to familiarize yourself with the causes of this problem and watch photos and videos, which describe in detail the processing of cucumbers.
Most often this happens when the greenhouse is very humid, you need to water the vegetables with less water. You can also use the tool BioGrow, it will speed up the recovery period.