What to do if the leaves of cucumbers in the greenhouse turn yellow?
As a rule, leaves of cucumbers grow red and dry as a result of improper care or non-compliance with growing conditions. Sometimes yellow foliage may indicate a lack of nutrients. What are the reasons that provoke a change in the color of the cucumber leaf plate and how to deal with it, let's figure it out together.
Why the leaves of cucumbers turn yellow in the greenhouse: the main reasons
There are several sources of yellowing of foliage. It is not easy to identify some of them, since they can be both single and complex. But all the same, before you start the fight, determine the factor that caused yellowness.
Important! Optimum moisture: at a depth of 10 cm, the soil should be moderately moist. At the same time, water should not fall on the greens, only the soil is watered.
If cucumbers are watered too rarely or with a small amount of water, then the bushes are quickly dehydrated. And the first sign that a vegetable signals this problem is yellow leaves. Excessive moisture also adversely affects the plant - it can rot. Pour cucumbers with cold water every other day.
Often the leaves turn yellow at the edges due to insufficient sunlight. If yellowness appeared just for this reason, do not worry: this is natural. Cucumber planting resembles the jungle - plants are also lush and dense. Therefore, it is difficult for the rays to make their way to the lower sections. In this case, nothing should be done, you can simply pluck dried leaves and wait for the harvest.
Did you know? The homeland of cucumbers is the foot of the Himalayas. In these parts, the vegetable grows by itself.
Sudden changes in temperature
Some, observing the rules of watering and giving enough light to the cucumbers, do not understand why the foliage turned yellow. The reason may be in the wrong temperature. And this is an important point when growing cucumbers. Usually, the wrong temperature rarely causes yellow leaves to appear, since the greenhouse protects the plantings from the winds, and the air inside cools more slowly if the greenhouse is hermetically closed.
Incorrect soil composition
Heavy, poorly aerated soils, depleted sandy loam, deficiency of organic, micro and macro elements or a glut of fertilizers with the soil cause the leaves to redden and curl up.
Bad pollination or lack thereof
Leaves and ovaries may turn yellow due to unsatisfactory pollination or lack thereof. Basically, this problem affects artificially pollinated varieties. However, poor ventilation of the greenhouse also negatively affects the pollination process.
Did you know? The calorie content of a kilogram of cucumbers is only 150 kcal. Therefore, the product is considered dietary.
Diseases and Pests
It is fungi and harmful insects that are most often to blame for the fact that the leaves turn yellow. With fusarium, pitiosis and other diseases, red spots first appear on the foliage, then they become completely rusted, dry and, finally, fall off. In this case, in case of defeat by fusarium, the lashes, the plants become lifeless and do not react to irrigation.
What to do and how to fix the problem?
Before you begin to fix the problem, you should find out the reason. Only after the source is determined, they begin to choose the means of combating it. As a rule, defeating the enemy is easy, you just need to choose the right tactics.
Important! The risk of fungus increases if hot days give way to rainy ones.
Proper plant care
Vegetables are most often affected by diseases due to breach of growing conditions. If the problem still arises, it's time to take action:
- Follow watering rules. During flowering and fruit development, cucumbers moisturize after 2-3 days at the rate of 10 liters per 1 m². In a drier period, the frequency of irrigation is increased, and in the rainy - reduced.
- Watch the temperature. Try to keep the optimal mode. Before fruit formation: during the day, on clear, sunny days - + 22 ... + 24 ° C, on inclement weather - + 20 ... + 22 ° C, at night - + 17 ... + 18 ° C. When the fruits appeared: during the day, on clear, sunny days - + 23 ... + 26 ° C, on cloudy days + 21 ... + 23 ° C, at night - + 18 ... + 20 ° C.
- Regularly ventilate. To cucumbers do not rot, it is necessary to ventilate the greenhouses. This will help reduce the risk of fungal infections. Airing is carried out sparingly so that the bushes do not have time to freeze.
- It is advisable to remove dried and curled foliage from the bushes. The lower leaves turn yellow with a lack of light and, being on the stem, simply consume food, which could go to the formation and ripening of fruits.
High-quality soil must be porous and saturated with oxygen. Therefore, the soil is periodically loosened, weeds are removed and covered with mulch. This will delay the evaporation of moisture, and the root system will be warm and provided with nutrients.
Important! Do not get involved in potent drugs - they burn the plant.
Pest or disease control
If, in addition to yellowed leaves, other signs of diseases or parasites are observed on the bush, treatment should be started immediately:
- Ascochitosis, powdery mildew, or infectious bacteriosis. Damaged areas are removed and burned. The remaining plants are treated with a 1% solution of Bordeaux fluid.
- Aphid. Nitroammophosk will help to get rid of it (3 tbsp. L. Per bucket of water). In the event of a massive lesion, the bushes are treated with Entobacterin, Biotlin, Fitoverm, Commander, Fufanon.
- Spider mite. With this pest they fight with a solution of cumulus (80 g per bucket of water). If the bushes are massively affected, not a single folk remedy can save, you will have to use acaricides (Vertimek, Kleschevit, Nissoran, Oberon, etc.).
- Root rot. The most effective way is to completely remove the bush. The place where he was is treated with copper sulfate.
To save the plant from yellowed leaves and to forestall the occurrence of the problem, you need to know how to feed the cucumbers:
- Nitrogen-phosphorus-potassium complexes. It is more correct to use ready-made preparations, but you can prepare them yourself: 10 g of ammonium nitrate, potassium salt and superphosphate are diluted in 10 l of water. The resulting mixture periodically fertilize the soil near the bushes.
- Infusion of herbs. The most harmless type of fertilizing. Natural remedies will make the cucumber lashes more healthy: 1 kg of fresh grass is poured with 10 liters of water and insisted for 7-8 days. The resulting mixture was diluted with water 1: 9. Applied not only as a fertilizer, but also as a means for spraying. After top dressing, wood ash is scattered on the soil.
- Urea, better known as urea: 40 g is diluted with a bucket of water, mixed with compost and water the soil.
Did you know? Smooth varieties of cucumbers are common in Europe. Therefore, species with pimples are called Russian there.
In order not to puzzle, from which the ovaries have dried up and the leaves have turned yellow, you need to try to prevent the occurrence of a problem.
To do this, adhere to such recommendations:
- Observe crop rotation rules. Cucumbers in one place are not planted every year. The best predecessors of this vegetable are pumpkin and zucchini.
- Proper watering. If it is not possible to water the cucumbers regularly, the beds are mulched to keep moisture longer, and open containers with water are left in the greenhouse.
- Fertilize the soil. The best feeding is considered an herbal infusion with an admixture of ash. Ash is rich in calcium and helps protect bushes from parasites. The foliage of such cucumbers will always be healthy and green.
- Do not plant seedlings too tightly. Such plantings do not allow the sun to reach the lower leaves and contribute to the spread of fungus.
To prevent parasites and fungus, from time to time, bushes should be treated.
To do this, you can use the following recipes:
- After the formation of 3-4 leaves and further, every 10 days, the bushes are sprayed with a solution in milk (10 l, 30 drops of iodine solution, 10 l of water, 20-30 g of laundry soap). Experienced gardeners argue that this method will forever forget the problem of wilting leaves and you will never have the question "why do not grow cucumbers."
- Overnight bread is soaked in water (1 loaf per 10 liters of water). The next day, the loaf is kneaded and iodine is dripped (a small bottle). This mixture is diluted with water (10 l) and treated with bushes.
- In June, the bushes are sprayed with a solution of soda (20 g per 10 liters of water). Alkaline environment will not allow fungi to appear.
- To repel pests, take an onion broth. This recipe is also suitable for buildings made of polycarbonate: 700 g of onion peel is poured with water (10 l) and boiled. After that, cover and insist 12-14 hours. The cake is squeezed out, the solution is filtered and diluted with water (2: 8). The resulting suspension is sprayed onto the foliage and watered.
- With the primary signs of rust on the leaves, the bushes are treated with a pale solution of potassium permanganate.
- Kefir and whey are used if the tips of the leaves begin to turn yellow: 2 liters of whey are diluted in 10 liters of water and processed cucumbers. To increase the process of fruit formation, sugar (about 150 g) is added.
- Biological products (Trichodermin, etc.) protect cucumbers well from fungi and infections. These products are absolutely harmless both to nature and to humans.
Learn how to grow cucumbers properly.
To maintain the soil in perfect condition, fertilizing should be done correctly:
- Regularly feed cucumbers with urea with humus. This procedure will not only support the foliage in a healthy state, but also extend the fruiting period.
- If the bushes give small fruits, you can apply a solution infused with rotted hay. For this, it is soaked with water for a couple of days. Concentration 1: 1. Processed with an interval of once every 7-9 days.