Many gardeners grow onions in their beds. Unfortunately, this healthy vegetable is sometimes a hassle for its owners. One of the signs of a dysfunctional onion is the yellowing of the leaves. Before taking on treatment, it is necessary to correctly establish the cause of the disease: it can be caused by pests and diseases, adverse weather conditions or poor care. It must be remembered that there is an effective treatment for any case!
Onions ripen by autumn, so yellowing at the end of August is a normal physiological phenomenon. But if the green feathers begin to turn yellow in spring or summer, this is a sign of improper development of the culture.
The reasons for this unpleasant phenomenon can be very different. The tips of the feathers quickly turn yellow in unfavorable weather, both too hot and excessively rainy. In addition, onions may turn yellow due to improper feeding; attacks of pests and some diseases.
Depending on the reasons listed, there are various ways to combat yellowing onions.
Weather conditions are the most unpredictable cause of potential bow problems. Even the most experienced gardeners cannot predict in advance how the weather will change.
Only a greenhouse can guarantee protection against changes in humidity and temperature - in it the onion feathers will always remain green
Greenhouse-grown onions usually do not turn yellow
If you grow onions outdoors, you need to be especially careful about the watering regime. In hot and dry weather, onion tips can turn yellow from lack of moisture. In this case, it is necessary to immediately water the plantings and then, during the dry period, watering every 3-4 days.
Onions require frequent watering with heated water
Onions generally love frequent watering. To avoid yellowing, young plants (the period of emergence and young leaves) of planting should be watered 2 times a week, and then about 5 times a month (if the weather is not too dry).
It is not recommended to use cold well water for watering onions: it must be collected in advance and left to bask in the sun.
Irrigation rate is 6-8 l / m2... After waiting for the soil to dry slightly after watering, be sure to loosen it.
In rainy weather and excessive watering, the onion rots from the rhizome. When the stems turn yellow, this means that the bulb is already completely spoiled and it is no longer possible to save it - it is better to immediately dig up all the spoiled plants.
Lack of nutrition is one of the main causes of yellowing onions. The lack of nitrogen especially affects the appearance (onions are especially picky about its content in the soil). The growth of the leaves slows down, they become short and thick in shape, at first light green, and then yellowing. If measures are not taken in a timely manner, the feathers will dry out, and after them the bulbs will also die.
When such signs appear, it is necessary to immediately apply nitrogen fertilizers to the soil. A good feeding is a solution of organic and mineral fertilizers: 1 glass of mullein or chicken manure infusion and 1 tablespoon of carbamide are taken in a bucket of water.
Keep in mind that pathogens of fungal diseases can enter the soil along with organic fertilizers.
Despite the fact that nitrogen is the most important nutrient for onions, its excess can lead to disastrous consequences - the bulbs rot right in the soil. Therefore, when applying nitrogenous fertilizers, it is necessary to adhere to the dose recommended for this variety.
Liquid ammonia is ammonia, or rather, its solution of 10% concentration. It contains nitrogen, so ammonia is quite suitable for feeding onions, especially since the ammonia solution is well absorbed by plants. True, the use of ammonia is a rather expensive pleasure, but if there are no other suitable substances at hand, then it will help you well to cope with the problem of yellowing of onions.
To feed onions, ammonia is diluted in water (55–60 ml per 8–10 l) and the beds are watered (it is better to do this in the evening).
In addition to providing nutrition for onions, ammonia improves the structure of the soil and helps to reduce its acidity. Another advantage of this product is a pungent odor that repels almost any pest.
According to the author (supported by his own experience), the key to the success of onion cultivation is planting in fertile soil. If you work hard to prepare a garden bed in the fall (put rotted chicken droppings or mullein in it and dig it up well), and feed the plantings three times during the season, you will not need to fight the yellowing of the feather. By the way, feeding should be carried out only during the period of growing leaves, and 2 months before harvesting, completely stop fertilizing.
Despite its burning juice, onions very often fall prey to various pests that can cause not only yellowing of feathers, but also the death of the crop. The most active destroyers of onions are the onion fly, onion moth, onion thrips, lurker (weevil), and stem nematode.
This pest resembles a common fly in appearance. It actively reproduces in April - May, just when the green onions are developing. The fly lays eggs on the surface of the stem, in the soil near the plants and under the leaves. After 8–10 days, small white larvae emerge, which penetrate the bulb and eat the scales. In affected plants, growth slows down, turns yellow, withers and, finally, leaves dry out.
To know for sure whether the fly is the cause of the yellowing, you need to dig out the ground and see if there are white worms on the bulb.
Onion fly is one of the most common onion pests
For the prevention of fly damage, the planting material must be soaked in a solution of potassium permanganate. To combat the pest, you can treat the beds with Mukhoed, Aktara, Kreotsid PRO or Kapate Zeon. However, the use of chemicals can reduce the quality of the crop.
There are also folk remedies for pest control:
To get rid of onion flies, the author successfully used a mixture of ash (1 glass), black or red pepper (1 tablespoon) and makhorka (1 tablespoon). This composition requires pollinating the beds. Before processing, all yellowed leaves are removed completely.
If your onion leaves become wrinkled and covered with yellowish veins, then most likely you will find a nematode in the stems - whitish filamentous worms. They suck the juice from the stems, penetrate into the bulb, causing cracking and rotting of its bottom. It is difficult to get rid of the nematode - it can live in the soil for many years.
Leaves affected by a nematode are deformed
To prevent damage, the planting material must be carefully processed (with hot water at a temperature of 40–45 aboutC, and then with a strong salt solution for 15–20 minutes), and in the fall (after harvesting) process the soil with Heterophos, Carbation or Tiazon. It should be borne in mind that these drugs are toxic and the waiting time after using them is at least 2 months.
Folk remedies for nematode control include:
Onion moths are similar in appearance to other species of moths. This pest activates when the weather is warm and dry. The moth lays its eggs in the ground near the bulbs. The emerging larvae penetrate the leaves and gnaw them from the inside. The feathers of the affected onion change color and dry first in the upper part, and then whole. The first wave of defeat is observed in May - June.
Onion moth larvae take root in leaves
Metaphos and Iskra are effective chemical means of protection. From folk remedies, processing with ash, tobacco dust, garlic or tobacco infusion is popular.
Onion (tobacco) thrips also often cause yellowing of onions. These small (smaller than aphids) insects, like aphids, suck the juices from the plant. They overwinter in soil and bulbs, so they can appear even in well-cultivated areas.
Despite its small size, thrips can inflict great damage.
For prophylaxis, onion sets must be treated with hot water (10-12 minutes), and then immersed in cool water. If infection of plants in the beds is detected, treatments with Iskra and Konfidor will help.
Sticky traps can be installed in the beds to assess (and reduce) the extent of thrips infestation. It is desirable that their paper base is yellow or blue - these colors attract insects. If the infection is not too strong, you can use folk methods of struggle:
Weevil larvae feed on the feathers of green onions. The first sign of damage is the yellowing of the feather, and then its wilting and the death of the plant. If you do not take up the fight in a timely manner, the entire garden bed may die. You need to carefully examine the plantings: if stripes appear on the green feathers, cut the feather - most likely, a weevil larva lurks there. The chemical means of control is Karbofos, which should be sprayed on the plantings (then green onions cannot be harvested for 2-3 weeks).
Other methods of dealing with weevils are:
Of the diseases of onions, yellowing is most often caused by fungal diseases: rot of the bottom, fusarium, rust. The main prevention method is to carefully select healthy seedlings and soak them in hot or salt water. The landing site should be sunny and well ventilated. Excessive soil moisture should not be allowed; it is also necessary to deal with pests that often carry diseases. Observance of crop rotation is not the last place in the prevention of diseases.
Before planting, it is advisable to treat the site with a HOM preparation - then the likelihood of a yellow feather appears.
It is not advisable to treat diseased plants with pesticides, because after them you cannot eat the feather for a long time. You can use Trichodermin (sevok is soaked in a suspension of 10 g / l of the drug), as well as Fitosporin-M or Gamair (plantings are sprayed with these drugs). These fungicides are biological products and do not harm human health.
Effective against yellowing of feathers caused by diseases, Metronidazole. A solution of 2 tablets per 5 liters of water should be watered over the beds (the norm is 4–6 l / m2).
Instead of determining the cause of the yellowing of the onion, choosing the right drugs and eradicating the problem, it is better not to allow this situation at all. If you treat the soil in a timely manner, correctly water and fertilize and regularly fight pests, then yellowing will most likely not occur (unless due to unfavorable weather). For prevention, you must adhere to the following rules:
Yellowed onion feathers are not a joyful sight for the gardener. However, adherence to simple rules of agricultural technology almost always helps to prevent this trouble, and if it has already happened, there is always a way to restore the health of the onion beds.
Hello! My name is Maria, 40 years old. My main job is teaching technical subjects.
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Many gardeners, especially those who are just starting to produce food, ask themselves a completely logical question: what to do so that the onion does not turn yellow? How can the current situation be corrected in the shortest possible time?
Many diseases of garden crops, including onions, are subject to this ailment. Yellowing is not temporary. And if you do not pay enough attention to such symptoms, you can ruin the entire crop.
Onions contain a complex of vitamins (groups B, C, E, PP) and mineral components (fluorine, iron, potassium, iodine, zinc, phosphorus, calcium, sodium), quercetin, sulfur, phytoncides, sugars (inulin, glucose, fructose) , pectin compounds, flavanoids, dietary fiber, saponins, essential oils, tannins, antioxidants, organic acids. Thanks to such an impressive list of phytonutrients, onions should be classified as biologically active products used to heal many breakdowns in the body.
A pungent taste and a rather pungent smell (up to tearing when cutting a root crop) is determined by the presence of allicins - essential oils with a high sulfur content. Phytoncides (a volatile constituent of essential oils) exhibit powerful antiseptic, antiviral and antimicrobial properties. One chopped onion is enough for a whole room to clear the air in the room of most protozoa, infections, viruses and bacteria, as well as microscopic fungi.
First you need to find out the reason why the onion tips dry, and only then think about how to water or process the garden. If this happened due to insufficient soil moisture, irrigation should be increased.
Tincture of mint, wild rosemary, pine needles and valerian will help scare off pests. It is advisable to alternate the onion beds with carrots, marigolds and calendula. Pests cannot tolerate the aroma of these crops.
Folk remedies used if the onion turns yellow:
Growing healthy onions in your garden is easy. The main thing is to adhere to the rules of crop rotation, watering, weeding and feeding. It is important to prevent diseases and pests and be sure to process the seedlings before storing and planting. Then the onions will not turn yellow and will yield a harvest of juicy, green feathers and large turnips.