Onions- one of the most common crops that can be found in any garden. And this is not surprising, because you can’t do without it in the kitchen. However, if for some reason the onion feathers begin to turn yellow, dry out, curl, and the plant itself begins to die, you may not get a harvest.
Why do onions turn yellow? There are many reasons: diseases, pests, and improper care.
Causes of yellowing onion leaves
In what cases is yellowing normal?
If the color of the onion feathers changed at the end of summer, that is, in August, then there is no need to worry. At this time it ripens, it is time to remove it, so the withering of the green part of the plant is a natural process.
In addition, there are varieties with early growing seasons. They mature a little earlier, so they ahead of schedule turns yellow.
Improper care
If at the height of summer instead lush greenery you see yellow feathers in the beds, the reason for this may be improper care:
- Not proper watering. Because of this error, the feather very often begins to turn yellow.
- Hot or rainy. If the summer was too dry, or, conversely, too rainy, the onions in the garden will change color.
- Nitrogen deficiency in the soil.
Also, quite often, onion leaves change color due to pest damage or disease.
Pests
Like any garden crops, onions have their own pests, due to which they gradually turn yellow and disappear. To save the harvest, urgent measures will have to be taken.
Onion fly
When lilacs bloom and dandelions bloom, this insect lays eggs near the onion or between its green leaves. After about a week or a little earlier, larvae appear from them, which gradually eat up the bulb. If no action is taken, the plant will die.
Onion secretive proboscis (weevil)
This is a small black beetle, which is also called a weevil. It wakes up in mid-April, and in May their eggs are already hiding on the leaves of plants.
After some time, the larvae hatch from them - yellow caterpillars with a dark head. They eat onion leaves from the inside, causing the onion to gradually turn yellow, curl and dry out.
Onion thrips
There is a group of pests that differ small in size(up to 1 mm) and feed on juice various plants- thrips. These include onion thrips.
Onion moth
Because of it, first the tips of the onion feathers turn yellow, then the whole plant. Adults fly only at night and lay yellowish eggs in the ground in beds near plants or near leaves. They hatch into greenish and yellow caterpillars about 1 cm long, covered with brown warts.
The caterpillars penetrate the leaves and begin to eat them, as a result, the onion disappears.
Onion diseases
Another reason why onion feathers change color is disease. There are many of them.
Let's look at the most common ones:
- Fusarium bottom rot. The bottom of the bulb is affected, and the onion turns yellow.
- Rust. Both onions and garlic suffer from it. Formations are visible on the feathers yellow. Both the greens and the bulbs stop growing and die.
- Bacterial rot. If you cut the onion lengthwise, you will see signs of disease on it. Onion scales become translucent and softened. The carriers of this infection are onion flies, thrips and other pests. If affected bulbs were planted, the plants will be depressed, with yellow leaves.
How to help yellowed plants?
What to do if the onion turns yellow, how to help the plants? To prevent plantings from suffering from pests and diseases, it is better to take preventive measures in advance.
However, if they have already attacked the onion feathers in the garden, you will have to use special preparations, which, of course, will also affect the quality of the harvest.
Onion fly
To combat it, the drug “Bazudin” is used. It helps against onion fly larvae. Mix 30 g of granules with 0.5 liters of sand and add to the soil. This amount of the drug should be enough for 15 square meters. m. of land. If the larvae are already inside the bulb, then spray the plantings with Creocide PRO.
Onion sneaker
If this pest has multiplied in an onion bed, it needs to be treated with Karbofos. Attention! After spraying, onion feathers are not recommended to be eaten.
First, prepare the solution: dilute 60 g of powder in 10 liters of water. Then treat the beds with it: 1 liter - per 10 square meters. m. landing.
Thrips
Is your plant suffering from thrips? Spray it with Confidor solution. It is not difficult to prepare: you need to dilute 1 ml of the drug in 10 liters of water. This amount is enough to process 100 square meters. m. landing.
Onion moth
The Iskra solution will help against it: dissolve 1 tablet in 10 liters of water. To process 10 sq. m of onion, 1 liter of solution is enough.
Bottom rot, bacterial rot and rust
If you planted affected bulbs, the plant will no longer be able to get rid of bottom rot. Therefore, check the planting material in advance and do not use one that is already spoiled. Or plant only onion varieties that are resistant to this disease.
Only pre-conducted preventive measures will also help against bacterial rot and rust.
Feeding and watering regime
If onion leaves turn yellow because there is little nitrogen in the soil, fertilize the beds with fertilizers that contain a lot of nitrogen. You can buy mineral fertilizers or use organic fertilizers. But remember, the manure must be rotted.
Most often, onions turn yellow due to improper watering. It is necessary to water the onions at least once every 3 days using warm water. If the soil in the garden bed is mulched, you can do this less often.
Prevention measures: remedies for yellowing of onion feathers
In order not to look for the reasons for the yellowing of onion tops in the middle of summer and not to get upset because of a spoiled crop, it is important to prevent the appearance of diseases and pest damage to the plant in advance. What to do?
Preparing the soil and onion sets
- Don't forget about crop rotation. Replant onion bed possible only after 4 years.
- Deep digging of the soil, which is done in the fall, is very important. Thanks to it, insect larvae that planned to overwinter in the soil will come to the surface of the earth and die from frost. For example, the onion fly hides at a depth of 20 cm.
- Loosening. Carry out deep loosening several times during the summer, which will help get rid of some of the pupae.
Before planting, keep the onion sets in hot water(45-46 °C) 10 minutes or soak for 15 minutes in a weak (pink) solution of potassium permanganate.
Prevention of onion fly damage
This fly cannot stand the smell of carrots, so plant onions next to carrot beds. Treat the beds with salt two or three times a season.
The first time the treatment is carried out when the onion feathers grow to 5 cm. Then water the beds with a salt solution: per 10 liters - 300 g. Next time the amount of salt will need to be increased. After 4-5 days of watering, do not forget to spill them with cold water.
This method is questionable, since then a lot of salt gets into the soil, and this will inhibit the plants that will later grow in this place, although it helps against insects.
Or treat the beds with a mixture of wood ash (200 g), tobacco dust and ground pepper (1 tsp each). And plant onions as early as possible, before the fly flies.
Rust Prevention
Spray the beds with a solution of copper oxychloride: dilute 1 tbsp in 10 liters of water. of the drug and add 1 tbsp. liquid soap. After a week, treat with Hom.
Also remember that dense plantings contribute to the spread of the disease.
Prevention of bacterial rot and bottom rot
Do not use diseased bulbs for planting. Before planting, treat the bed with Hom by preparing a solution: 40 g of the drug per 10 liters. For 1 sq. m you will need 500 ml of solution.
Do not use sets affected by bottom rot. Once the onions are ripe, be sure to dry them in the sun for at least 7 days.
If you do not forget about preventive measures, water and feed the onions on time, then the beds will delight the eye with their bright colors all summer long. green. And in the fall you will reap a rich harvest!
Video: why did the onions in the garden turn yellow and what to do?
Good afternoon, dear readers!
Anyone who has even a small yard has a small bed of onions. What can we say, if there is a lot of land, then there is more space allocated for it. Unfortunately, onions often get sick and turn yellow right in the garden - what to do in this case? And this is one of the headaches of any summer resident.
If it changed its color in mid-to-late August, then it’s okay - at this time it is almost ready for harvesting. And if the feathers or tips of the onion turn yellow at the height of its growth and formation in June-early July, then urgent measures need to be taken.
What to do if the onions in the garden turn yellow
Reasons why onions turn yellow
First, you need to understand the reasons for onions turning yellow. They can be different:
- lack of microelements in the soil
- insects - pests
- illnesses
- improper care
The first reason is lack of nitrogen
A common cause of yellowing onions is a lack of nitrogen in the soil. Onions are especially hungry in hot weather, since nitrogen is absorbed only in dissolved form. Also, during rainy times there is a lack of nitrogen. Water washes everything away beneficial properties from upper layers soils that are so necessary for growth in the first half of summer.
Reason two - pests
Onion fly - looks like a regular one. Its larvae cause more harm. When they hatch, they penetrate the bulbs and eat them from the inside. The leaves turn yellow and dry out, and the bulb itself rots. To check, you need to click on the onion. When damaged it becomes soft. Or pull the bulb out of the garden and carefully examine the roots - there may be small white worms on them.
Secretive proboscis, aka weevil — little beetle, has a black or dark gray color. It eats the pulp of the leaves, on which white stripes or dots then appear. Affected leaves dry out. Unlike other pests, it does not harm the bulb itself, only the green leaves.
Reason three - illness
Fusarium mushroom infects the bulb, which subsequently produces diseased plants. A mycelium appears and gradually penetrates the leaves. They turn yellow, break, and become lethargic.
Alternaria blight- develops on leaves affected by gray rot. Watery spots appear that turn brownish. The spot enlarges and takes on an ovoid shape. It begins to develop, the onion leaf breaks. If a spot forms on the neck of the onion, a constriction appears that affects the scales of the bulb.
Root rot- spots form brown on the ground or slightly below. The spots grow and cause the underground part of the onion to rot. Onions become infected from the moment the seeds appear, or may die even before they appear on the ground. Rot develops due to large stagnation of water in the ground.
Pink rot— first the onion roots turn yellow, then turn pink, dry out and die. The bulb stops growing, but this has little effect on the leaves. In some cases, the ends dry out.
Gray and cervical rot- small white spots with a light green edging around appear on the leaves. The onion grows slowly, the leaves are crooked, rotting closer to the neck of the bulb. A gray coating forms between the scales of the bulb.
Is the most dangerous disease, since rot develops imperceptibly and slowly. Upper part The bulbs become soft and a fluffy coating forms. The bulb becomes covered with a black coating and infects healthy ones.
Reason four - improper care
Onions, like many plants, love moist soil; for this you need to moisten it more often. Preferably in evening time. But don't flood it. About 7 times a month.
Improper watering is the most common mistake when growing onions. Proper watering includes not only giving water to water, but also feeding. Loosen the soil more often, both before and after watering.
How to help onions not turn yellow?
Folk remedies for help
Salt for onion flies and onion diseases
When the length of the feather reaches about 8 cm, you need to carefully, without getting on the leaves, water the soil with saline solution. A 10 liter bucket requires 200 grams of salt. When adding ammonia(100 g) the effect will increase. This method should be used no more than four times per season, as it leads to soil salinization. To prevent this from happening, you should try to pour the saline solution only on the bulbs, trying not to get it on the ground or leaves.
Rescue from overheating
Onions do not like overheating; this negatively affects the roots of the plant, which leads to yellowing. That's why onions grow well early spring in greenhouses when it is still cool. In summer, you can cover the plants with covering material to ensure straight sun rays did not cause harm. But growing onions in the shade of trees does not work - the feathers stretch out and thin out - the bulb almost does not grow.
Replenishing nitrogen in the soil
To replenish stock nutrients and nitrogen, you can use urea or ammonium nitrate and sulfate. And also use complex mineral fertilizers.
The simplest and fast way introducing nitrogen will be an infusion of mullein.
To get rid of onion flies, use a mixture of lime and tobacco, in equal ratio. Calculate 6 grams per 1 square meter. Etching should be done with the first appearance of flies, and repeated after a week. For a 10 liter bucket we take 200 grams of tobacco and the same amount of lime, let it sit for a couple of days. Store in a dark place. Dilute twice and spray.
What to do if you water in moderation, and there is no sultry heat, but the leaves turn yellow? There is only one conclusion - the plants lack strength. During planting, the onions spent a lot of energy, so to speak, they ate all the useful substances in the soil. Over time, they became exhausted and remained hungry.
To help you need to dilute it in a 5 liter bucket liter jar litter, and let it brew for a couple of days. We take a bucket of water, pour a liter of this medicine and water it between the rows. Thus, we feed and give strength for further growth.
If the onion has already turned yellow, there is a method that will help it recover. For a 10 liter bucket, warm water, pour a couple of handfuls of ash, an ampoule of ammonia, 100 grams table salt. Stir well and pour over. Carefully. Water should not wet the feathers themselves.
This method helps with onion fly and other pests and diseases. To consolidate the result in the fall, you need to dig up the soil. The deeper, the greater the likelihood successful harvest next year.
With proper and healthy care, onions will delight you with their rich and pleasant green color.
Video about yellowing onions
In the fight for your harvest, it is better to resort to folk remedies, and not to poison with chemicals, which will harm not only people, but also the soil. Now you know why onions in the garden turn yellow and how to help them.
Sincerely, Sofya Guseva.
Other useful articles.
Every summer resident has a garden bed in which he always grows green onions. Unfortunately, it is not always possible to collect good harvest. If onion leaves dry out in August or September, this is normal. IN in this case There is no need to panic, as the bulb is ripe and it is time to harvest. When the feather turns yellow in June, it’s a reason to sound the alarm. In this situation, it is necessary to determine the cause and eliminate it. Yellowing of onion feathers occurs due to pests, diseases, lack of nitrogen, poor care And weather conditions. Now let’s figure out why the onions in the garden turn yellow.
The following pests cause significant damage to onion crops: onion fly, onion weevil, onion nemothad, onion tribes and onion moth. The female fly lays eggs under dry onion scales or between green stems. She starts doing this in May. After one week, the larvae bite into the bulb and begin to actively feed. The larvae of the secretive proboscis eat the pulp in the leaves. The longitudinal passages that they then leave are clearly visible through the thin skin of the feathers.
A nematode is a small, barely noticeable worm. Its larvae feed on onion juice. This pest is also dangerous because it settles in the ground for decades. Thrips larvae feed on the juice of not only onions, but also garlic, cucumbers and other plants. The insect also overwinters in the soil, hiding in the remains of vegetation. Moth larvae, caterpillars and moths damage onion crops from May to October. The larvae feed on the sap, while caterpillars and butterflies spoil the feathers and leaves.
How to protect onions from pests?
The above insects can feed on onions without interfering with each other. Therefore, most effective way combat them - do comprehensive prevention. The following preventive measures will help save onions:
- change of landing site;
- early boarding;
- processing nigella sets in hot (45 degrees) water for 5 - 10 minutes. Can be processed in saline solution(120 g of salt per 3 liters of water) 15 - 20 minutes;
- planting only healthy sets;
- planting carrots, calendula or tagetis nearby (flies cannot stand their smell);
- use of repellents (200 ash, 20 g ground pepper, 20 g mustard powder, 20 g tobacco dust). The resulting mixture is sprinkled with nigella onions;
- soil treatment with “Confidor” (1 g per 10 liters of water) or “Iskra” (1 tablet per 10 liters of water);
- treatment of the pen with “Creocide PRO” (if the tips begin to turn yellow);
- treatment with “Karbofos” (treat in case of mass appearance of the secretive proboscis). Important! After spraying, onion feathers can be used for food only after some time, and after being thoroughly washed.
- thorough cleaning of remaining vegetation after harvesting (the bulbs and feathers of green onions remaining on the ground are an excellent place for pests to overwinter);
- Digging the soil before frost begins.
Insects damage the onion stem from the inside and from the bulb, and it begins to turn yellow from the tip
Yellow leaves are a disease
Onions also turn yellow due to illness. Among them is rust, bacterial rot and rotten bottom. Under the rust there may be fungal infections that have similar signs - spotty yellowing of the feathers, followed by blackening and wilting. To identify bacterial rot, cut into the onion. Between the normal scales you will see that one layer is rotting. Such an onion will not be stored and will quickly rot. This disease occurs due to bacteria carried by onion flies, thrips and other pests.
To prevent planted nigella onions from getting sick, you will need simple folk methods:
- warming the bulb before storage;
- 12-hour warming of the bulb before planting at a temperature of 35 - 40 degrees;
- water the onion feathers during the growth process with copper oxychloride (re-watering after 1 week).
Nitrogen deficiency is bad
When there is no nitrogen in the soil, onion leaves, particularly their tips, dry out and turn yellow. In this situation, there is only one help - feed with nitrogen-containing fertilizer (organic and organomineral products).
Improper care and bad weather
Inappropriate watering regime, inappropriate temperature and water hardness, overheating lead to the nigella onion feathers turning yellow. While rooting and beginning to grow, water the green onions generously once or twice every three days. If mulch is used on the soil, watering once is sufficient. When watering, the water should have a temperature of +18 to +25 degrees. Watering time is the first half of the day. To reduce water hardness, add special means. It wouldn’t hurt to feed the onions either. The composition of the bait is as follows: 10 liters of water, 50 g of ammonium nitrate, 20 g of superphosphate and 20 g of potassium salt.
Overheating has a negative impact primarily on the roots. Because of this, they die off, which in turn leads to yellowing of the green onion stem. Mulch will retain moisture and protect the soil from overheating. As a result, the roots, tips and feathers of the onion will be fine.
Dry summers and frequent heavy rains cause the onions to dry out and begin to turn yellow, even in the absence of the above reasons. To protect onions from the vagaries of nature, plant them in a greenhouse.
To prevent the onion from turning yellow, water it special solutions and try not to fill it with water
Conclusion
To preserve onions until the end of the season, plant them earlier than usual, next to carrots and calendula, change the planting location every year, sprinkle the soil with pest repellents, water correctly and completely remove any remaining vegetation for the next season.
Remember, only comprehensive prevention will protect onions from insect enemies, prevent disease and prevent yellowing of feathers. It is quite possible to grow green onions on your own plot. If you follow all the recommendations listed, onions will please not only beautiful view, but also taste.
It is impossible to imagine a housewife's kitchen without onions. It may bring tears to your eyes, but in many dishes the vegetable is necessary. Therefore, onions are grown everywhere on private plots. It is planted either for winter or spring. Onions are growing well. Quite rarely he is capricious and shows dissatisfaction. But it signals serious problems. Often - yellowing of the feather.
What to do if the onion turns yellow? It all depends on the season. If the onion began to turn yellow in June, for example, then this is bad. The plant is not happy with something. Or someone got started in the garden. You need to figure out why the onion feathers turn yellow and take action. If this happens at the end of July, then there is no reason to worry. The harvest began to ripen. We'll be cleaning up soon.
Provocateurs of yellowness:
Why do onion leaves turn yellow? Causes of the problem: a pest has infested, there is not enough nitrogen in the soil, the plant lacks moisture. Rescue measures will depend on the specific cause.
Pests:
As a rule, the plant is damaged by flies and secretive proboscis.
Onion fly
Symptoms of its presence: feathers turn yellow and wither early, a larva can be found in the bulb, the vegetable rots, and the plant is pulled out of the ground very easily, even accidentally during weeding.
Pest targeting:
1. Size adult- about seven millimeters. The body is yellowish-gray with dark sparse stripes.
2. Larva – white worm with cone-like processes at the end. It can be seen in the bulb or in the soil around the plant.
Fly pupae overwinter in the soil. In spring, the pupae wake up. The laying of eggs coincides with the flowering of dandelions. After a week, the larvae appear. They make their way into the bulb and feed on it.
Protective measures:
Deep digging of the soil before sowing;
early boarding;
proximity to carrots, the smell of which repels flies;
destruction of infected plants;
sprinkling the ground around the onion with ash mixed with tobacco dust;
removing all plant debris from the garden bed.
Onion sneaker
Very dangerous pest, which eats feathers from the inside. Signs of its invasion: on the leaves - white spots and longitudinal stripes, yellow tips of feathers, curling and drying of feathers. For young plantings, both adults and larvae are dangerous.
How to recognize a pest?
1. Adult beetle – small insect up to two millimeters long. The body is covered with light scales. The tarsi and elytra are brownish. There is a light stripe at the base of the elytra.
2. The larva is a light worm with a dark head.
Secretive proboscis overwinter in the ground, grass, bushes or unharvested onions. This is what they feed on in the spring, gradually moving to fresh plantings. The female gnaws the onion feather and lays eggs there. After two weeks, the larvae are born. They eat the inner contents of the feathers and then descend into the soil to pupate.
Protective measures:
timely removal of plant residues;
sowing on ridges distant from the previous year’s plantings;
regular loosening of row spacing;
cutting off damaged feathers plus loosening.
Lack of nitrogen in the soil
It can be observed both on dry days and on rainy days. Nitrogen is absorbed in dissolved form, so moisture is needed. At the same time, after heavy rainfall, nitrogen compounds go too deep, where the plant’s roots cannot absorb them.
To compensate for nitrogen deficiency, onions are periodically fertilized with saltpeter, ammonium sulfate, urea or slurry.
Lack of moisture
During active growth To gain strength, onions need regular watering.
The plant is watered before and after weeding;
pour water into the grooves made between the green bushes;
for dense plantings, when you have to water the feathers, use a watering can so that the water does not wash out the soil around the bulb;
The need for watering is checked with a finger; if the soil is dry at the depth of the nail, then you need to water it;
One and a half months before harvesting, watering is stopped.
Feather Rescue:
Let's look at a few traditional methods comprehensive fight against the problem. That is, recipes that allow you to eliminate several causes at once.
1. Dissolve half a glass of table salt and one ampoule of ammonia in ten liters of warm water. Add three grains of ash. Water with this mixture once every ten days. Until the feathers turn green again.
2. Soak the planting material in strong potassium permanganate and plant it in rows sprinkled with salt.
3. For half a bucket of water - half a tablespoon of iodine, two bags of potassium permanganate and five hundred grams of soda. This is a concentrated composition. It also needs to be diluted in water in a ratio of 1:10. And water it already diluted.
4. Sprinkle the rows with sand mixed with naphthalene.
5. Water the onion with salt water and potassium permanganate.
Onion - this one vegetable crop grows in literally every garden, and almost every gardener sooner or later faces the problem of yellowing feathers of this plant. There are many reasons for this phenomenon, but only one can be perceived by gardeners completely calmly - this is when the feathers turn yellow and lie down when the bulb ripens. All other reasons for yellowing of onion arrows are unacceptable and you must know them and be able to eliminate them, otherwise you may be left without a harvest. But before we take on the reasons and start learning how to eliminate them, let's talk about how to protect your onion from yellowing of its feathers as reliably as possible.
Simple rules for preventing yellowing of onion feathers
So, in order for the onion feathers to be a healthy color before harvesting, it is necessary to treat the area correctly, water it on time, use modern means control diseases and pests and take into account other rules for its cultivation.
Rule one - adherence to crop rotation, remember that it is not recommended to plant onions in the same place more often than once every four years, otherwise pests and diseases accumulate on the site, and onions consume plenty of nutrients from the soil.
Rule two - correct feeding . Fertilizers must be applied correctly and in the optimal quantity, not forgetting that both a lack and an excess of fertilizers do not bode well.
Rule three - proper watering. Onions like moderate, but one might say constant, watering. The soil should not become too dry and the soil should not become significantly waterlogged.
Rule four - do not run the site. If you notice that the onion feathers have begun to turn yellow, it is better to remove them and burn them. This way you can stop the spread of infection or pest.
Rule five - deep digging. It is advisable to dig up the soil for onions using a shovel full with a turn of the layer in order to minimize the number of harmful microorganisms in the soil.
This the most important events, one might say, prevent yellowing of onion feathers, but it also happens that they do not help, and the onion still turns yellow. What are the reasons and what to do about it?
As we have already mentioned, there are quite a few reasons for the yellowing of onions; it could be a manifestation of a pest or disease, incorrect agricultural practices, the influence of weather, or a lack of nitrogen in the soil.
Pests that cause onions to turn yellow
There are quite a lot of pests whose vital activity leads to yellowing of onions: these are onion moths, tobacco thrips, onion worms, stem nematodes and, of course, onion flies.
Onion moth
Typically, onion moths are most active when it is hot and it rarely rains, and the soil is dry. At this time, the onion moth butterfly appears, little different from the one we are all used to house moth. The damage is caused by its larvae, which hatch from the eggs laid by the butterfly. The presence of larvae leads to the fact that first the tips of the onion feathers begin to dry out, and then the entire feather dries out completely.
To know how to fight onion moth, you need to know its biology. For example, the onion moth lays its ovipositor near the bulbs in the soil. Caterpillars hatched from eggs have a light yellow body color and are about a centimeter long. Having hatched, they move towards the feathers, climb into them and begin to gnaw out the tissue from the inside, which leads to yellowing and withering of the feathers.
Before using insecticides, such as Metaphos, you should try to fight onion moths with folk remedies, for which you can treat the feathers and the soil around with stove ash, scattering it evenly, as well as tobacco, you can directly from cigarettes, or spray the soil and plants infusion of garlic (a couple of cloves per liter of water).
Tobacco thrips
Onion, or tobacco thrips - it also leads to yellowing of onion feathers. Thrips are smaller in size than aphids; like them, they feed on cell sap, which leads to yellowing and drying of onion leaf blades. Thrips overwinter in the soil and bulbs, those that were left for planting on next year, therefore, even when planting seedlings on an ideal site in all respects and following all agricultural practices, onions can still suffer from this pest.
To prevent thrips from getting into your area with the seedlings, before planting, you need to immerse the seedlings in water with a temperature of 45-47 degrees above zero for a quarter of an hour, and then in cold water for 10 minutes.
If the pest appears clearly, then folk remedies They are unlikely to help; insecticides must be used here. To combat thrips, you must use insecticides, strictly following the instructions, such as Iskra or Confidor.
Onion sneaker
Its vital activity is another reason why onion feathers may turn yellow. The larvae of the secretive proboscis literally eat onion feathers and at first they change color to a lighter one, then they turn yellow, wither and die. If the pest is not controlled, it can destroy most of the onion plantation.
The most annoying thing is that this beetle moves quickly, and even if you take into account crop rotation, fertilizing and watering, and take good care of the soil, it can still appear on your site, having flown from a neighboring one.
In order to minimize the risk of beetles appearing on a site, it is necessary to dig up the soil, remove and burn plant debris, and observe crop rotation. The soil around the beds must be sprinkled with wood ash or mustard or pepper powder, this may repel insects.
When a beetle appears in small numbers, these individuals can be collected manually. If there is a lot of pests, then it is necessary to use insecticides, strictly following the instructions on the packaging. Previously, the drug Karbofos helped effectively, but then it was banned and you need to look for other approved analogues.
Stem nematode
Another reason for the appearance of an atypical color of onion feathers is a stem nematode. Essentially, this is a small worm that can penetrate the bulb and cause cracks at the bottom of the head, it begins to rot, and leaf blades- turn yellow and die. Usually the nematode is very small, no more than one and a half millimeters, but the harm it causes can be colossal. If a nematode has entered your area, then no crop rotation will most likely help; it can live in the soil for up to ten years, and sometimes longer.
To prevent nematodes from entering your site through onion sets, before planting, you need to immerse it for a quarter of an hour in water heated to 45 degrees above zero, and then in salt water- for half an hour.
Gardeners say that when the soil is infected with a nematode, an infusion of marigolds can help get rid of it - 2-3 kg of vegetative mass of marigolds per bucket of water is the norm for 2-3 square meters of soil.
There are also insecticides to combat nematodes, these are Fitoverm and the new drug Nematophagin BT.
Onion fly
Almost the most common pest of onions, the larvae of which happily eat any of its varieties. You can usually tell that it is the onion fly that is to blame for the yellowing of the feathers by how the leaves begin to deteriorate: first they turn yellow, then they begin to wither.
To prevent onion flies from entering the area, beds with onions must be alternated with beds of carrots. The aroma of carrots can repel onion flies, and the smell of onions can repel carrot flies, so you have double the benefit.
If the number of individuals is small and the damage from them is not yet very significant, then the affected plants can be treated with a solution of salt and ammonia, but remember that salt is dangerous for the soil and it is better not to carry out such treatments more than once per season. To obtain the solution, you need to dissolve 200 g of salt (no more!) and a tablespoon of ammonia in a bucket of water. After this, you can treat the soil and affected plants with the solution, using this amount per five square meters of bed.
Mixtures of ash and tobacco, as well as pepper and mustard in equal parts, have a much more beneficial effect on the soil, but less effectively on the pest. You need 25-30 grams of these substances per square meter.
If folk remedies do not help, which happens quite often, insecticides must be used. The drugs Aktara, Sochva and Tabazol will help you cope with onion fly.
Onion diseases
In addition to pests, diseases can also turn onion leaves yellow, for example, bacterial rot, bottom rot, rust and a number of other less common ones. Usually diseases on onions are fungal or bacterial; they can appear on the site after being introduced from planting material or insects. Taking this into account, when sowing onion sets, you need to carefully sort them out, removing all those onions that show signs of infection. The remaining bulbs should be placed in water at a temperature of +45 degrees for 10-15 minutes, then dipped in salt water (a tablespoon per 300 g of water) for 8-10 minutes.
Do not forget that diseases are more active in soil that has excess moisture and in shaded areas, so you need to water the onions often, but moderately, and select a leveled and well-lit area for it.
In addition, diseases can be transmitted by pests, so even if there are few pests on the site, you still need to fight them.
If you do not want to use chemicals to fight diseases, then at least treat the affected plants with copper-containing preparations: HOM, Oxyx, Bordeaux mixture and others, if this is also inappropriate on your site, then remove the affected plants to prevent the diseases from spreading further.
Mistakes in caring for onion beds
From improper care Any plant can suffer and onions are no exception. The most common mistakes are planting onions for many years in the same place, improper feeding and watering.
Lack or excess of nitrogen in the soil
Onions are almost the only vegetable that is very picky about nitrogen in the soil. Onion feathers can turn yellow either from a lack of nitrogen or from its excess, so you need to be careful with the addition of microelements. If the feathers have turned yellow, then dig up one bulb; if you have not found any signs of pest infestation and the bulb is apparently intact, then the feathers may have turned yellow due to a lack of nitrogen. To replenish it you need to carry out foliar feeding: it is enough to dissolve 45-55 g of ammonium nitrate in a bucket of water and use the resulting solution on a couple of square meters of onion beds.
In general, onions can be fed only a couple of times during the season, the first time as soon as the shoots appear and the second time after 12-14 days. You can use nitroammophoska for this by dissolving a tablespoon of fertilizer in a bucket of water; this amount is enough for three meters of beds.
If there is an excess of nitrogen in the soil, traces of rotting will be clearly visible on the dug up bulb. In this case, you need to add superphosphate and potassium sulfate to the soil. You need a teaspoon of both in a bucket of water, this is the norm for a couple of square meters of bed. After a week, you can loosen the soil and add wood ash 100-150 g per square meter.
Improper watering of onions
If the onion is underfilled or overfilled with water, its feathers will begin to turn yellow. You need to water the onions every day better in the evening, settled water at room temperature. A bucket of water is enough per square meter, but only if there is no rain and it is hot. If there was even a little rain during the day, then watering may not be carried out; if there is no rain, but it is cold (below +20 degrees), then the water rate can be halved.
Conclusion
So, as you understand, there are quite a few reasons why onion feathers begin to turn yellow. Before taking on chemistry, assess the condition of the onion, try to find pests, assess the condition of the soil, and so on, only then make a decision in favor of using chemistry. Sometimes the situation can be saved by simply removing several atypical plants from the site and observing simple rules care Don’t forget about prevention, especially if you are sowing unfamiliar material.