Yellowing of onion leaves: causes and treatments. Why do onion leaves turn yellow on top? Diseases and pests that can cause discoloration, wilting or drying of onion leaves.
- Yellowing of onion leaves due to incorrect agricultural practices
- Onion leaves yellowing due to lack of water
- Yellowing of onion leaves that do not contain enough nutrients
- Yellow onion leaves due to pests
- Diseases that turn yellow onion leaves
- Why do onion leaves turn yellow? From time immemorial
- Natural recipes to prevent yellowing of onion leaves
Yellowing and wilting of onion leaves is a normal process at the end of the season, when the crop is approaching harvest. But sometimes onions turn yellow early – spring or summer. In this case, emergency measures must be taken. To prevent onions from turning yellow, you can use folk remedies and specialized remedies.
Yellowing of onion leaves due to incorrect agricultural practices
Often the yellowing of onions is caused by errors in the application of cultivation technology. It is important to take proper care of onions so that the leaves do not wilt if you want to get good production. If the leaves die too soon, the plant will not be able to manufacture food for growing onions in the soil.
Onion leaves yellowing due to lack of water
Yellow onion leaves appear suddenly if the soil in the garden or field is dry. Perhaps the crop is thirsty, and there is not enough water for the plant to maintain its green leaves.
The solution – proper onion watering: observe the watering regime. In the first half of summer, onions are watered twice a week, in the second half – once a week. Irrigation rate 6-8 liters per 1 square meter. Of course, in dry weather, the garden is watered more often. Onions are watered at a temperature of 18-25 ° C directly under the root, preferably in the morning.
Onion leaves yellow due to fertilization
Another reason why the tips of the onion leaves turn yellow is the lack of micro or macro elements in the soil. Usually it is a nitrogen deficiency. Due to the lack of these elements, onion leaves become short and thick. Later, you can see that their color is not healthy green, but yellowish.
Solution – fertilizing the onion crop. How to feed onions so that they do not turn yellow? Nitrogenous fertilizers are needed. It is better to use organic matter – infusion of manure and urea (1 tablespoon of rotted manure and 1 tablespoon of urea are taken for 10 liters of water and infused for a few days).
Yellow onion leaves due to pests
The problem of yellowing of onion crops cannot always be solved by adjusting the irrigation and fertilizing regime. Sometimes the infestation of harmful insects is responsible for the yellowing of onions.
If you can’t find the cause of the onion turning yellow, cut off a bad-looking onion leaf. If you notice small white worms inside the leaf, know that the onion is attacked by a stem nematode, which is one of the most dangerous pests of onions.
Unfortunately, only high-quality preventive treatment of seedlings and soil before planting helps to combat onion nematodes. In the summer, when the caterpillars migrate from the bulb to the leaves, it remains to remove the affected plants and immediately burn them to prevent the pest from destroying the entire onion crop.
The onion fly – Delia antiqua – lays its eggs at the base of the leaves or on the ground next to the onion several times a season. The first generation of these insects begins to affect crops in late spring – early summer.
If you find small yellowish larvae with brown warts inside a yellow onion leaf, you need to take immediate action against the onion moth.
Since onion moths go into hibernation in the butterfly stage, treating the bulb will not help prevent damage to the plant. In this case, it is necessary to treat the land with an insecticide.
Onion bites affect spring crops in April-May. The main sign of an attack is when only the tips of the onion turn yellow, and not the entire leaf. If you dig up the plant, you can see that the bulb has rotted.
Unfortunately, as with most pests, it is easier to prevent than to try to save plants that are already infected. In the event of an onion fly attack, pollination of the aisle with a mixture of tobacco dust and sunflower ash, in equal proportions, will help. Affected plants are dug up and burned.
If the onion leaves turn yellow and become transparent, then the plant is eaten from the inside by the larvae of the onion beetle. These are white-yellow legless larvae with a brown head, up to 0.7 cm long.
If you see beetles on the leaves, they can be collected to prevent eggs from breeding on the leaves. It is also useful to mulch the soil around the onion crop with ash. Plants eaten by caterpillars must be removed and burned.
Onion (or tobacco) thrips are small pests up to 1 mm long, but very dangerous for various crops. When plants are affected, white spots form on the leaves, which later merge and change the leaf color.
In order for the anti-onion tripe effect to be strong, the crop is sprayed with an insecticide. Before planting, the bulbs are disinfected with hot water (immersed for 10 minutes in water at a temperature of 45 ° C), and then washed with cold water. Damaged plants should be burned.
Diseases that turn yellow onion leaves
Why do onion leaves turn yellow? One answer might be that you have a culture that is attacked by a number of diseases that can cause this sign as well. If you notice the first signs of illness – act immediately!
Onion bacterial rot
Bacterial rot “always comes associated with” thrips, onion flies and other pests – insects that infect bulbs with this disease. Symptoms of bacterial rot are: lifeless yellowing onion leaves, dried flower stalks, rotten onion.
In the fight against bacterial rot of onions, only preventive measures will help: get rid of the affected bulbs, treat the soil before planting and burn the affected plants.
Onion stalk rot
If the onion is attacked by stem rot, you will notice yellowing and drying of the onion tips. If you dig into an onion, white mushrooms will be visible on the bottom. As soon as mold appears, a pink fungus appears between the scales, and the bulb itself becomes soft and watery.
To prevent onion stem rot, treat the bulbs before planting (soak them in a fungicide). You burn diseased plants.
Symptoms of rust on onion leaves appear in May and June. You will notice yellow spots that then form from swollen pillows. With the development of the disease, the leaves turn black and fall off.
In the fight against rust in onion cultivation, only prevention is effective. In addition to pre-treatment of bulbs and soil in early summer, spray with a solution of copper oxychloride soap (1 tablespoon of medicine and liquid soap to 10 liters of water). After a week, the treatment can be repeated.
Why do onion leaves turn yellow? From time immemorial
Yellow onion leaves can appear when the weather is not conducive to the growth of the crop. Rain or prolonged drought in summer combined with extreme temperatures – too cold or too high, affect the harvest just as badly. Because of this, onions turn yellow – onions and leeks. There are no varieties of onions that can withstand the vagaries of the weather.
To prevent yellowing of onion leaves due to weather conditions, follow the forecast and take necessary measures. When very high temperatures are announced, water the onions in time, and when there is frost, cover the onion crop to protect it.
Natural recipes to prevent yellowing of onion leaves
A number of natural recipes are useful to prevent yellowing of onion leaves due to pests and diseases. Here are some of the organic remedies you can do to protect onions:
- soak chives in a fungicide solution before sowing;
- work the soil well, and then listen to the onions after planting;
- Mulch the soil with ash.
- Cigarette ashes scattered on the floor.
- Remove diseased plants immediately. It must be destroyed by burning.