What to do if yellow spots appear on the leaves of cucumbers and how to treat
Cucumbers can be found at their summer cottage at almost any vegetable grower. It is quite difficult to find a person who would not like fresh cucumbers. During the cultivation of this vegetable, some are faced with the fact that yellow spots appear on the leaves of cucumbers. Therefore, before growing, it is recommended to learn how to cure yellow spots in cucumbers.
Why do cucumbers change the color of the leaves
Before treating yellowing, you should figure out why yellow spots appear on the leaves of cucumbers. There are several of the most common causes of this problem.
Nutrient deficiency
The main reason for the discoloration of the leaves is a lack of magnesium or potassium. Because of this, red and dry spots begin to appear on the plant. At the same time, at first only the edge of the leaves is affected, and the rest of them begins to turn yellow only after a few days.
With a severe magnesium deficiency, the leaf plates between the veins are affected first. The first to change their color are the lower leaves, and only after that the lower leaves of the cucumbers are covered with spots.
If the problem arose due to a deficiency of nutrients, then you should use the medicinal onion infusion. For its preparation, 100 g of husk is added to 10 liters of water. Then all this is thoroughly mixed and boiled for about 20 minutes. When the prepared mixture has completely cooled down, you can start the cucumber treatment. Each bush is treated with a liter of the prepared infusion.
Peronosporosis
Spots on the leaves of cucumbers in the greenhouse and on the street can appear due to powdery mildew. To find out that the plant has turned yellow from peronosporosis, its main symptoms should be studied. When this disease occurs, only the lower part of the bushes suffers first. A faint bloom of gray with a slight purple tint appears on it. A few days after the onset of the disease, the spot begins to spread to the entire bush.
The leaves gradually dry out and over time, because of this, the plant may completely die.
Most often, spots on cucumber leaves due to powdery mildew appear when grown in high humidity conditions. Therefore, before treating yellow spots on cucumber leaves, you should lower the moisture level.
To protect cucumbers from the appearance of peronosporosis, you must:
- water the bushes with heated and settled water;
- collect the ripe crop in a timely manner;
- monitor crop rotation.
When the first signs of the disease appear, you must immediately stop watering the plants and treat them with Bordeaux liquid. You can also use polycarbacin during treatment.
Cladosporium
Sometimes, the leaves turn yellow due to the plant suffering from cladosporiosis. This cucumber fungal disease has pronounced symptoms and therefore it is quite easy to distinguish it from other diseases.
At the initial stage, small round dots appear on the sheets. At first, their size is only 1-2 mm, but after two days they begin to grow and dry. At the slightest touch with the hand, the blotches that appear are destroyed.
For the prevention of cladosporia, it is necessary:
- plant cucumbers in a new place every year;
- regularly ventilate cucumbers in the greenhouse;
- use only heated water during watering;
- before planting cucumbers, completely clear the site of plant residues that were previously grown on it.
If yellow spots have already appeared on the plants due to cladosporiosis, then you should immediately suspend watering for a week. For treatment, it is recommended to use foundationol or Bordeaux liquid.
Anthracnose
Yellow spots on cucumbers in the greenhouse and in the garden, often appear due to anthracnose. Most often, anthracnose appears due to the fact that not disinfected seeds were planted. Also, the plant can become infected due to the fungus in the soil.
When this disease appears on cucumbers, several blotches of red color can be seen near the veins. Literally 2-3 days after infection, the leaves begin to dry quickly, and dark ulcers appear on the fruits.
Getting rid of the disease is quite simple. To do this, plants should be treated with Bordeaux liquid and a weak solution of copper sulfate once a week. Some growers then sprinkle the cucumber bushes with lime or charcoal.
Field mosaic
There are times when the cucumber seedlings gradually begin to turn yellow due to infection with field mosaics. This disease appears equally often both in greenhouses and in vegetable gardens. On each leaf of bushes infected with this disease, at least one speck of yellow color appears near the vein.
If nothing is done, then over time the entire bush becomes covered with such spots. This reduces the number of flowers, which is why the yield deteriorates. To cure a field mosaic, it is enough to treat the bushes with whey several times a week. The procedure is carried out until the leaves begin to recover.
How to treat yellow leaves
The fight against yellow spots on cucumber seedlings is carried out with the help of special preparations that help to treat certain diseases of cucumbers. Therefore, before treating cucumber seedling disease, you should familiarize yourself with the most effective drugs.
Topaz
With the help of this fungicide, you can quickly get rid of fungal diseases, due to which the leaves of cucumbers are covered with specks. Also, this tool is often used to prevent these diseases. The main advantage of Topaz is that it is not toxic and therefore it cannot harm human health in any way.
This tool is available in various forms. It is most commonly sold as a blue powder or liquid solution. When using powder, you will have to deal with the preparation of a working solution. To do this, 10 g of the drug must be mixed with 10 liters of water. For ten square meters of land, at least two liters of the mixture should be consumed.
Hom
Some vegetable growers use Hom after the cucumbers began to become covered with yellowish spots. Most often it is used as a replacement for Bordeaux liquid. This remedy is very effective against many different fungal diseases. The preparation contains copper oxychloride, which has a contact effect.When this substance hits the surface of the leaves, it prevents infectious agents from penetrating into plant tissues.
Hom is sold in the form of a green powder, which must be dissolved in water before use. To do this, 30 g of the fungicide is mixed with 5-7 liters of water and infused for half an hour. It is recommended to use Hom once a week in calm weather. If spots appear on almost every leaf, then the mixture should be used more often.
Zircon
You can get rid of the yellowish spots that appear with the help of Zircon. This drug not only protects young bushes from diseases, but also activates their growth. You can use Zircon at any stage of cucumber development. Many vegetable growers use it even during pre-sowing soil preparation, before planting in greenhouses.
The product is absolutely safe for people, since there are no chemical components in its composition and the product consists only of elements of plant origin.
Before curing the yellowing of the leaves, you should prepare a working mixture. For this, the container is filled with 2-5 liters of water, after which 25 g of the drug is added to it. Then the mixture is mixed and poured into a ten-liter bucket of water. The finished substance is used once a week until the bushes are fully restored.
Oxyhom
If the cucumbers have small brown spots on the leaves, then you should use Oxyhom. With it, you can protect plants from various diseases or cure them. The main advantages of the drug include its long-term therapeutic effect. Having used this remedy for yellow spots several times, you can forget about fighting them for a long time. After penetrating into the leaves, Oxychom affects almost all the most important components of the fungal cells, which led to the yellowing of the leaves.
The drug is sold in powder form, and therefore it is worthwhile to prepare a working solution before use. 20-40 g of the drug is added to a filled ten-liter container. All this is thoroughly mixed and poured into smaller containers. The tool is used every two and a half weeks.
Conclusion
Many vegetable growers do not know what to do with yellow spots on cucumber leaves. To prevent yellowing from appearing, you should familiarize yourself with the main causes of their occurrence and the means that will help get rid of them.
Many summer residents are faced with such a problem as yellowing of the leaves on cucumbers. There can be many reasons. These are aphids, diseases, and temperature changes. I use the remedy BioGrow, helps well in plant growth and has not yet noticed yellowing of the leaves. True, I used it only for the first year, but I liked the result. Another method is very effective. Save up banana skins in winter and freeze them. And when it comes time to plant the cucumbers, just bury them in the ground. And so continue periodically throughout the flowering period. Cucumbers will be green until autumn. High yields.