Why onions turn yellow: how to water and feed?
Onion is a well-known culture and generally quite unpretentious, but it also requires some attention. It is relatively well resistant to waterlogging and drought, but very sensitive to the soil environment and weeds. The usefulness of the vegetable is undeniable, it is used in recipes of all cultures of the world. The process of growing strong golden heads and picking juicy bunches of greens in early summer is a pleasant and rewarding activity if the plant is not sick.
The reasons
The quality of onion ripening is affected by the place of planting and illumination, night frosts (especially in spring), lack or excess of moisture, soil environment, feeding methods. Diseases caused by fungi or parasitic insects can reduce the yield of onions. The most common problem in onion beds is yellowing of the tips of feathers or entire individual leaves. Until the cause is clarified, do not immediately fertilize the onion. Drought can provoke such a reaction.
Intense heat for several days, lack of natural precipitation and irrigation in the complex can lead to a slowdown in the movement of fluid in the green part. This does not affect the plant's ability to form large bulbs so critically, and the problem can be solved by resuming watering. Yellowing of onion leaves is a completely natural process if it occurs along with lodging at the end of summer. However, it happens that the leaves suddenly turn yellow in June, or a vegetable planted before winter acquires a pale yellow color in May.Do not panic, because there are many ways to urgently correct the situation.
There are a number of factors that could cause the feather to turn yellow and dry. The first step in saving the crop will be to identify the causes of painful changes. The main reason for the yellowing of onion leaves is the wrong site for planting. The crop requires good, light, neutral soil.
With acidified soil, it is ennobled by adding lime, dolomite flour, wood ash or chalk. This measure protects the plant from yellowing and helps the bulb develop well. The site may also be slightly alkalized, but in this case, onions should be planted there 2 years after treatment.
If everything is in order with the soil, and the tips of the onion have begun to turn yellow, then most likely the reason lies in the banal lack of water. Compliance with the irrigation regime is very important for onions. In normal weather, in the first phase of growth, the plant is watered twice a week, then once is enough. In dry and hot weather, the frequency of watering increases. Onions are watered directly under the root in the first half of the day or in the evening before sunset. It is desirable that the water is soft.
After drying the top layer of the earth, the aisle must be loosened, which will provide better air circulation to the roots and a good flow of water and nutrients to the bulb.
The plant loves moisture, but due to its excess, the soil will lose valuable minerals. The onion head will form small and tasteless. In addition, excess moisture always serves as a good breeding ground for various pathogenic fungi and microorganisms. If the weather is rainy, the air has high humidity, then watering can be completely stopped.There is enough moisture for the onion. It is difficult to save a rotten bulb, therefore, in rainy weather, you should not overmoisten the bed with excessive watering. A week before digging the onions stop watering completely.
The temperature regime also significantly affects the color of the pen. If possible, you should try to arrange the onion bed so that it is in the shade for several hours. The plant is quite sensitive to overheating, as a result of which not only the aerial part turns yellow, but the roots may also die. Onions do not need absolute shade, which can negatively affect yields. The feather can dry out with suddenly returning frosts even in June, although in principle the plant is cold-resistant. Care of the beds in this case remains the same. When the feather grows up, the damage will become invisible in the general green mass, which will not affect the taste in any way.
To speed up the release of a plant from a state of stress, it should be helped to restore strength. Ashes or charcoal are used for powdering between rows. If you want to speed up the effect, you can use fertilizer beds with a solution of ash. It is necessary to dilute 2.5 cups of dry matter in 10 liters of water and leave for 3-4 days. The tips of the feathers will no longer turn green, but the plant will get a good boost of mineral nutrients and growth will be faster.
If the deadlines for planting onions before winter are not observed, it may happen that, without having time to take root, the bulbs give green sprouts. Due to early spring frosts, they die. A urea solution will help save the seedlings at the very beginning of the yellowing process.
It is best to plant onions before winter at least three weeks before the onset of frost. Then he will have time to form a good root system.
The feather may also fall off due to landing at insufficient depth. Such an onion freezes in winter, some of the roots die off. In the spring, such plants do not have enough strength to grow, so the feathers dry and droop. To avoid rotting turnips, it is best to plant winter onions 4–6 centimeters deep into the soil. After that, for better heat preservation, the crops are sprinkled on top with a layer of peat mixed with sawdust.
Often the feather dries out from a lack of trace elements, the most necessary of which for onions is nitrogen. The shape of the leaves will also indicate the lack of this substance: they grow short and thickened. Recognizing this onion disease is simple. All plants located in the neighborhood also, as a rule, become faded, the fruits grow small, change their shape, the leaves can bend around the edges. The application of nitrogen fertilizers is the only possible help for onions. It is important to do this moderately and carefully, as excess nitrogen can cause over-growth of green mass and chopping of the bulb.
Fertilizer can be prepared by yourself. For this, any grass, hay, weeds, food waste of organic origin (vegetable peels, tea leftovers) are suitable. The capacity is half filled with such waste. You can add old homemade wine or a few tablespoons of spoiled jam here. It will serve as catalysts for the fermentation process like yeast.
In warm weather, the concentrate will be ready in 3 days, in cool weather - in a week. Readiness can be recognized by the characteristic smell of decay. A liter of this mixture is diluted in a bucket of water and the onion beds are well watered. It is better to fertilize in rainy weather or after preliminary watering.So, the nutrients will be better absorbed, delivering a whole set of nutrients for both the development of the bulb and the growth of greenery.
The color of the aerial part also changes when the plant is damaged by pests and pathogens. The stem nematode is one of them. These are small thin white worms that can be seen on a cross section of the affected leaf. Onion moth is one of the most common pests of this crop. She lays her eggs in the ground from early spring through the summer. Yellow-brown caterpillars inside the feather will indicate the defeat of these insects.
In the spring, the onion fly can also infect the plant. Its larvae from the base of the stems move to the bulb, which quickly rots. When plantings are infected with fly larvae, it is the tips of the feathers that turn yellow, and not the entire green part as a whole. The onion weevil eats the plant from the inside. In this case, the feathers not only turn yellow, but also begin to shine through. If you look closely, you can see the passages left by the yellowish caterpillar in them.
Onion thrips are difficult to distinguish with the naked eye. This extremely dangerous pest reaches only one millimeter in length. When affected by thrips, the leaves acquire a pale grayish tint. It's all about the very small white spots left by insects. Gradually they merge, the sheet acquires an uncharacteristic shade. The secretive trunk is a small gray beetle with a body up to 2.5 millimeters. He spends the winter in the soil, and with the onset of heat, he attacks the culture, while the onion greens dry out and fade.
Onion feathers affected by various diseases also do not tolerate delay. Bacterial rot is an almost constant companion of thrips and onion flies.Pests through their larvae infect the bulbs. The disease is indicated by rotting of the bulb, yellowing of the feathers, lethargy of the peduncles. If the feathers have already died, the plant cannot be saved. When this incurable disease is detected, the affected parts of the plant are destroyed by burning. The vacant bed is treated with a strong antifungal agent ("Hom" or "Oxyh").
Bottom rot is a very common disease, with the tips of the feathers drying out first. If you dig the bulb itself, then on it you can see the defeat of the porcini fungus. In especially advanced cases, the bulb becomes already soft and watery. Rust can appear on onion leaves at the very beginning of summer. With this disease, yellow spots first appear on the feathers, which then become convex (as if warty).
If you do not take action, then the feathers will turn black and fall down. Pre-planting treatment will help to avoid the onset of the disease: before wintering the crop, the bulbs are well dried and heated.
Alternariosis is another onion disease. Fungal disease first covers the green part of the plant. White spots form on it, which then turn brown. After some time, the disease also captures the bulb, which becomes moldy and rots. Onion leaves can turn yellow due to climatic surprises, and heavy rains, prolonged lack of precipitation, too hot summers, and sudden prolonged colds equally affect the bulbs.
Choosing a tool
Getting an excellent crop of large bulbs or succulent feathers depends on the grower. It is necessary to decide which means will become assistants in the fight against possible pests of the plant.There are well-tested ready-made insecticides and herbicides that are easy to use. The gardener is only required to read the instructions and dilute the substance in accordance with the recommendations on the package. If onions are grown for the household, especially when collecting feathers for eating, then pesticide treatment will have to be abandoned. In this case, they use folk remedies, biological fungicides that do not harm humans.
Among pesticides there are widely used and known to every gardener, such as Iskra. This drug helps in the fight against a wide range of insects on various crops. Others can be purchased at a pharmacy, like Metronidazole. It is known as one of the most effective antibacterial agents for combating the yellowing of onion feathers. For preplant treatment of seedlings, the Trichodermin fungicide is used. And during the period of vegetative growth of the onion, the planting is sprayed with Fitosporin.
Do not forget folk remedies. It is believed that carrots, marigolds and common calendula planted next to the garden bed or in its aisles can scare away pests.
Do not tolerate many insects and mint aroma, as well as wild rosemary, valerian and conifers. Infused water on these herbs or spraying with a solution with aromatic oils will serve as a good prevention of the appearance of unwanted guests on the ridge. In the fight against the onion fly, 2 full tablespoons of ammonia and one glass of table salt, diluted in 10-12 liters of water, will help. With this solution, water the earth carefully, trying not to get the product on the leaves.
A solution of manganese and iodine is also considered a well-known folk remedy for yellowing of the pen.To prepare the concentrate, take 2 sachets of potassium permanganate, 10 milliliters of iodine and a glass of soda. The ingredients are well stirred in water at room temperature. The resulting solution is diluted by adding 10 liters of pure warm water per liter of concentrate. Watering the beds will help in the fight against fungi and improve the condition of the soil, reducing its acidity due to the soda that is part of it.
You can protect the onion from the nematode with the old simple way of preparing the set. Before spring or autumn planting, it is soaked in salty warm (about +45 degrees) water for 15–20 minutes. If insects have already appeared, then treatment with marigold infusion will help. To prepare it, half a bucket of flower heads is poured with warm water and kept in a dark place for 2 days. Strained infusion is diluted in 10 liters of water and 40 grams of grated solid or liquid soap are added. The solution is sprayed on the ground, avoiding contact with the green parts of the plant.
How to process?
After the discovery of pests and their traces in the garden, a natural question immediately arises about what to do next. After identifying the cause of the problem or the type of pest that attacked the plantings, they choose a measure to combat it. In order for the onion to quickly move away from the consequences of the disease, it must be properly fed. Among the many means of prevention and protection in the fight against dangerous onion pests, there are several of the most well-known and affordable.
- If the plant lacks nitrogen, fertilized with organic matter. An infusion of manure and ammonia is suitable: for 10 liters of water you will need a glass of well-rotted cow manure and a tablespoon of urea. After the mixture is infused, it is carefully poured over the greens under the root.They also use with a lack of nitrogen and complex mineral fertilizers (azofoska), and a weekly infusion of green mass on water. To obtain an easily accessible organic fertilizer, the container is filled by two-thirds with any plants, the remaining volume is filled with water. The resulting mass is diluted with water 1: 10 and watered onions. With a lack of nitrogen, folk councils recommend watering plants with a solution of brilliant green: 10 drops of the substance are taken per 10 liters of water.
- From plant damage nematode early prevention can help. Before planting, the ground and bulbs must be treated with a solution of potassium permanganate. To do this, the seedlings are soaked in a weak pink solution, and the bed is watered with saturated pink water two days before the intended planting. If the larvae have already damaged the feathers, which is noted too late, then the only possible way out is to dig up the entire crop and burn it.
- Eliminate alternariosis modern antifungal drugs, such as Acrobat, Fitosporin, will help. To avoid further contamination of the soil after harvesting the onion, the husks and all organic residues in the garden are carefully destroyed. The following year, the crop is sown in another area. If, nevertheless, some bacteria manage to overwinter, then in the new season they will again attack the onion crops.
- With worms fight by feeding onions in early June with ammonium sulfate. The solution is prepared from 2 tablespoons of the drug, diluted in 10 liters of water. This amount should be enough for two square meters of cultivated area.
- In the fight against onion moth, as a rule, use ready-made insecticides. They have a wide spectrum of action and are used for both spraying and basal treatment.The consumption of the product and the frequency of processing are indicated on the packaging. On average, one tablet must be dissolved per bucket of water.
- As with most insect pests, the appearance onion fly It is easier to prevent than to deal with it. Tobacco powder or ordinary ash helps to save onions. They are sprinkled between the rows when planting. Another proven remedy is to alternate onions with rows of carrots in the same bed when planting. These plants mutually repel the pests of a neighbor in the ridge. The disadvantage of this method is the difference in the mode of watering crops, since carrots require more frequent and plentiful watering, in which the bulbs can rot. If you water the carrots according to the onion schedule, then from a lack of moisture it can grow poorly, acquire a bitter aftertaste.
- A good folk remedy in the fight with onion fly is a solution of tobacco, red pepper and laundry soap. To prepare it, 200 grams of tobacco must be poured with three liters of hot water and insisted for three days. Then a tablespoon of soap and ground red pepper are added there, and the mixture is diluted in 10 liters of water.
- onion weevil afraid of ash, mustard and ground black or red pepper powder. Mulching the row spacing will prevent the appearance of the insect. And you can also process onions with Karbofos. If the plant is affected, then it will have to be burned.
- With onion thrips most effectively can be controlled with any available insecticide. The treatment is carried out prophylactically every 2 weeks from the moment the feathers germinate by 5–8 centimeters. Before planting, the bulbs can be treated with saline for 2-5 minutes.
- Secretive Trunk effectively destroyed by spraying "Karbofos".It will take 1.5-2 tablespoons of the drug per 10 liters of water.
- When fighting fungal diseases preventive measures are the most effective. So, in order to avoid the appearance of bacterial rot on onions, the healthiest seedlings are initially chosen. They and the land are cultivated before sowing. If the plant has time to get sick, then it is burned.
- So that the bulbs do not rot the bottom, before planting they are soaked in a fungicide. Infected plants are destroyed.
- rust It is also easier to prevent than to treat. Presowing treatment of bulbs and beds in the spring gives a good result. During the summer, the plant is treated with a soapy solution with the addition of copper oxychloride. In a bucket of water, a tablespoon of soap and the same amount of copper preparation are diluted. Processing is carried out no more than once every 1.5–2 weeks.
Prevention
Onion is one of the most common crops in our home gardens. Despite all efforts to feed, water, weed and loosen, the problem of yellowing of onion foliage often arises. The problem can be prevented before it occurs. To do this, there are a number of effective measures.
- We should not forget about crop rotation and neighbors in the beds. Do not plant onions every year in the same place. An onion bed can only be reused after four years. A good result will be given by planting onions along with carrots. But a relative of garlic will become a bad neighbor.
- In the spring, you should strive to plant onions as early as possible. He will have time to come into force. It will be easier for the plant to resist the onion fly.
- The state of health of the seed material is of great importance. Sevoc before planting is treated with a solution of potassium permanganate or salt. Choose the healthiest, most undamaged bulbs for planting.It is good to lower the bulbs for 10 minutes and into hot water +50 degrees.
- The bed should also be prepared in advance. Traces of the previous crop in the form of tops or grass are carefully removed. The earth is shed with a solution of potassium permanganate, sprinkled with ash or mustard powder. Just before sowing, it is recommended to disinfect the soil with copper sulphate (a tablespoon of the substance is added to a bucket of water). Onion aisles can be filled with calendula flowers. These plants repel many insects well.
- Digging the soil is done before frost. Insect larvae will be at the top and die, unable to withstand the cold.
Important! The described activities are best carried out in a complex manner, since the plant can be affected by several types of insects at once, which are frequent companions of various fungal diseases of onions. A comprehensive approach to protecting the bow will certainly give a good effect.
For information on what to do when onion leaves turn yellow, see below.