Onion diseases, description and treatment - the most effective remedies + photo

Downy mildew or powdery mildew

A common fungal disease of the plant is considered to be downy mildew, the causative agent of the infectious process is conidia. This is a spore that causes light green or yellow spots to appear on the stem during the vegetative growth of the plant. In sunlight in the morning, you can observe the presence of a grayish-purple fungal coating, which is why the plant appears dirty. Remember, the disease is spread by insects, humans, wind and rain. Causes of the disease:

high air humidity (95%) at a temperature of +15° C
abundance of weeds
evening and frequent watering
onions were not processed before planting

How to treat onion peronosporosis, how to fight it? There are quite a few ways, but the greatest positive effect is achieved if drugs against peronosporosis are used:

suspension Polycarbacin
carbamide (urea)
1% Bordeaux mixture
Ridomil Gold

downy mildew of onion - in the photo

We prepare the first two like this - dilute 40 g of the drug per 10 liters of liquid and spray the stems two or three times at intervals of 10-12 days. Polycarbacin does not leave burns on the leaves of the plant and is low-toxic, but the last treatment should be carried out no later than 20 days before harvesting the onion. In addition, onions treated with Polycarbacin cannot be cut into feathers.

You can make 1% Bordeaux mixture by adding 100 grams of copper sulfate and 100-150 grams of slaked lime to 10 liters of water. Ridomil Gold should be used in several stages - when the first warm days of April appear, and in May, when powdery mildew is most likely to appear, for preparation, dilute 25 g in a bucket of water.

Downy mildew of onion, folk control measures:

Chop any weeds growing in the garden and fill a bucket halfway with them, add hot water + 60 ° ... + 70 ° C, let it brew for 2 days, strain and spray onion
Pour onion peel (250 g) into 10 liters of water, boil, let it brew for 2 days, and treat the plantings at intervals of 7-10 days
Pollinate the beds with wood ash at the rate of 50 g per 1 m²

downy mildew - pictured

Follow safety precautions when using fungicides and remember to wash the product before use. Prevention of peronosporosis:

process planting material
remove weeds and plant debris
remove fallen stems
plant onions in a warm and ventilated area

Onion diseases

Onions are one of the crops that not every gardener grows, and one must imagine the risk associated with the possibility of plantings becoming infected with both viral and fungal diseases. This applies both to onions grown for turnips and to those varieties whose nutritional value is the green feather.

Despite the fact that the essence of the diseases, of which there are several dozen, is different, we can assume that the approaches to their treatment are relatively uniform. Thus, fungal diseases, which are especially severe in conditions of high humidity, can be cured with a limited number of drugs if this is started on time. Viral diseases, as a rule, cannot be treated; diseased plants must be destroyed. However, viral diseases can be prevented by fighting their distributors - a variety of harmful insects.

Powdery mildew

Powdery mildew is a disease that is not unique to onions, and its symptoms are similar in all cases. They can appear at the very beginning of spring: for perennial onions soon after the leaves grow, for those planted in early spring - a little later. Yellowish spots appear on the leaves, soon their color turns into a grayish-lilac, this phenomenon is accompanied by the formation of an abundant white powdery coating, reminiscent of flour.

This coating, especially noticeable in the morning, gradually darkens, becoming brownish-pink, the leaves become brittle, dry out, and the bulbs stop growing. The disease manifests itself especially often in dense plantings, in rainy weather, and with a lack of sunlight.

Usually the source of infection is seed material, so its disinfection before planting is mandatory. Both seeds and sets can simply be kept in hot water (40–42 ºС) for 6–7 hours, or even better - in a pink solution of potassium permanganate. To increase the guarantee of neutralization after this, some gardeners use treatment with biofungicides (such as Baktofit or Polyram).

In addition to processing the planting material, careful cleaning of plant debris after digging up the onions and immediate digging of the bed helps prevent onion infection next year. Crop rotation is also of great importance: it is better to change the location of the onion bed every year, but if it remained in one place for 2-3 years, then take a break for the same period. A good preventative measure is the periodic scattering of wood ash on the onion beds, and among chemical agents, the autumn treatment of the soil with Horus or Oxyx.

If the disease appears, you should sharply reduce the amount of watering and stop nitrogen fertilizing, and treat the onions and the soil around them with fungicide solutions (for example, Bordeaux mixture or Polycarbacin). Of course, it will not be possible to eat onions very soon after such treatments, and feathers may not be worth it at all. However, the bulbs can be saved if the treatment is carried out in a timely manner.

Downy mildew (downy mildew)

Symptoms of peronosporosis are similar to the symptoms of powdery mildew: first, a gray-purple powdery coating forms on the feathers. Subsequently, the leaves become deformed, darken and dry out. In this regard, the entire plant weakens, which can lead to death: the bulbs begin to rot. The disease spreads very quickly throughout the garden bed. It can appear about a month after the feather begins to grow; it is promoted by the same factors as powdery mildew.

With peronosporosis, everything looks like powdery mildew, and the control measures are similar

Both prevention and treatment of the disease are almost the same as in the case of powdery mildew. Peronosporosis in the unadvanced stage can be treated well with infusions of various weeds (dandelion, nettle, etc.), which are also fertilizers. An effective remedy is the drug Ridomil Gold.

Video: combating downy mildew on onions

Gray or cervical rot

Neck rot rarely appears directly in the garden bed: this can only happen in the case of prolonged rains that occur after the feathers have lodged. Typically, signs of the disease become noticeable about a month after harvesting. The bulb at the very neck becomes wet and begins to rot, and the rot quickly covers its entire volume. The husk becomes covered with gray mold, due to which the nearby bulbs become infected.

Since the causative agent of the disease penetrates the bulbs through mechanical damage, a good preventative measure is to periodically disinfect the knife used to trim the feather by rinsing it with a dark solution of potassium permanganate.

Most often, bulbs that are stored under-dried, as well as those with particularly thick necks, become diseased. Therefore, proper drying of the crop is of great importance: it should last at least one and a half weeks at a temperature of about 30 ° C and good air ventilation.

Neck rot starts at the top, but then the entire bulb rots

Among the chemicals, Quadris is sometimes used, which is used to treat the soil in the onion bed a week before harvesting. Pre-sowing treatment of seedlings with fungicides, as well as thorough cleaning of all weeds and plant debris, is also essential.

Gray mold

Gray mold is a fungal disease; The fungus can infect bulbs at any time: this can happen both during growth and in winter, when storing the crop. Unlike gray rot, this disease does not affect the neck of the bulb, but develops on all other parts of it. The sources of infection are the same as in the case of cervical rot. Tissues affected by the fungus become flabby, become cloudy, acquire a disgusting odor and yellowish color, and become covered with a gray coating. Measures to prevent infection are the same as for cervical rot.

Fusarium (Fusarium bottom rot)

The source of the disease lives in the soil, onion infection occurs during the growing season, and is favored by rainy weather, especially in the later stages of plant development. Rotting begins from the lower parts of the bulb, moving towards the top, the bulb becomes watery, the roots and leaves quickly die. It is also possible that infection occurred, but did not have time to manifest itself during harvest; then the bulb will rot during storage, especially at high temperatures.

Bacterial rot of onions

Bacterial rot, like fusarium, can manifest itself already in the garden bed, towards the very end of onion growth, or maybe only during storage. Even in the garden, onion leaves may be covered with small, wet wounds, but they are difficult to see, so the gardener sends the crop for storage without expecting trouble. The disease can appear only closer to winter, gradually destroying the bulb. Bacterial rot is noticeable only when cutting the onion: normal scales alternate with softened, translucent ones. Soon the entire bulb rots, emitting an unpleasant odor.

With bacteriosis, the bulb rots from the inside

As a rule, bacterial rot develops in unripe and poorly dried onions; the source of infection is unharvested plant debris, on which bacteria can live for several years. Therefore, careful cleaning of the beds after harvesting, as well as compliance with crop rotation, are absolutely necessary. In addition, damage should not be allowed when digging up onions and transporting them.

Onion rust

Rust is a common fungal disease of all onion plants, as well as garlic. This is a real scourge of perennial onions grown for greens. When infected, convex spots of various shapes of light yellow color form on the leaves, which can change color up to bright orange. These spots (“pads”) are fungal colonies. As a result of its influence, the development of leaves, and subsequently the bulbs, stops.

Rust only looks beautiful, but it can destroy crops.

Rust is extremely contagious, and its causative agent is stable, and if plant debris is not carefully removed after the end of the gardening season, onion infection can continue in the garden for several years. Infection is facilitated by saving space: you cannot thicken the plantings, no matter how much you would like. In general, the measures for preventing and treating the disease are the same as in the case of other fungal diseases.

Mosaic bow

Mosaic is a dangerous viral disease that cannot be cured. When infected, onion leaves become flattened and various spots, stripes and streaks form on them, mostly yellow, sometimes whitish. The bulbs lengthen and their ripening stops. Subsequently, the leaves fall prematurely and many plants die. The probability of complete loss of the crop is low, but its quantity and quality are significantly reduced.

Since small insects (ticks, aphids, nematodes) serve as carriers of the virus, prevention of infection consists of fighting them. In addition, timely extermination of weeds, moderation in watering and fertilizing, correct crop rotation and avoidance of excessive thickening are extremely important.

Onion jaundice

Jaundice is also a viral disease and cannot be treated. When attacked by a virus, the feathers and arrows of onions turn yellow, starting from the tips and gradually completely changing color. The leaves become flat and often intertwine. The bulbs stop growing. The carrier of the virus is the cicada, on which, as well as on various weeds, it overwinters. Affected onions must be destroyed. Preventive measures are the same as for mosaics.

Curly

When talking about onion curl, there is an inaccuracy: there is no disease under that name, but feather curl (or curliness) of feathers accompanies various, mainly viral, diseases. Most often, feathers become curly when infected with mosaic or jaundice. In addition, the onion stem nematode also carries a disease such as ditylenchosis. Nematodes are almost invisible to the naked eye, live in the ground, and damage both onion bulbs and foliage. As a result, the bulbs crack, and the feathers, intertwined and curly, eventually droop and die.

Onion rust

The disease is caused by a fungus that spreads well in a humid environment and affects the stem and growth of turnips, so it is advisable to eradicate it immediately. The disease, onion rust, is expressed by bright orange-yellow swollen spots, round in shape, which then turn into black dots. The reasons for the appearance include early planting, densely planted beds, an abundance of weeds and excessive watering.

It is worth noting that the fungus only eats into a wet leaf; it will not penetrate into a dry feather. If onion plantings are exposed to rain for a long time, fungal spores quickly germinate and take root. If the onion is sick, most likely the currants and other shrubs will be affected by the disease. Due to the fact that diseased feathers do not work well, the yield is reduced.

rust using garlic as an example - in the photo

Prevention of the disease:

treat planting material with bactericidal agents (for example, potassium permanganate solution)
plant varieties resistant to the disease (Sprinter)
fight weeds and remove plant debris from the beds
cut off damaged stems and burn
do not plant onions too thickly

During the period of massive growth, onions should be sprayed with copper oxychloride. To prepare the solution, take 30 grams of the substance, the same amount of liquid soap and dissolve it all in a bucket of water. The treatment must be repeated after 7-10 days. It is better to carry out processing during the day so that the feather has time to dry. Hom, Tilt and even furatsilin cope well with rust (10 tablets need to be diluted in a liter of water).

Onion rust appears at the end of April; if you notice the first signs of the disease, stop watering the plant and fertilizing it with nitrogen fertilizers, and get rid of damaged stems. Perennial onion species are most susceptible to the disease, and their treatment is also urgent.

Onion pests

Onion diseases are directly related to insect vectors, because they (insects) carry viruses and fungi throughout the onion plantation (and not only the onion plantation).

The tips of the leaves turn yellow (what is this)

This problem, when the tips of the leaves on onions turn yellow, worries novice gardeners. But experienced gardeners don’t worry about it, because they know what to do about this problem.

What is this, let's figure it out. And so, this is not a disease, but here we observe the activity of onion fly larvae or nematodes, which crawl into the tips, sit and eat there. And that's because the ends are tender and soft and juicy.

Borbaa

consists of watering the plantings with onions with a saline solution, where 1 glass of salt goes to a bucket of water.
We do the procedure 2 more times with an interval of 10 days. Important
. Salt destroys larvae, but it will not spare earthworms either, so we use it with caution.

On a note!
Pests can be repelled by periodically sprinkling tobacco dust on the onion plantings. Alternatively, you can simply pinch off the yellow ends and burn them. And then, treat the plants with growth stimulants. This is how we help the onion fight stress.

Fusarium bottom rot

The disease is caused by a bacterium in the soil that affects the tops of the plant and leads to the death of the feather along the entire length, as well as to the rotting of the turnip, the bulb becomes softer and more watery, and characteristic rot of the bottom of the onion appears. The causes influencing the occurrence of the disease are:

excess moisture in the soil
late harvest
poor quality planting material
the growing season takes place in hot weather

onion fusarium - in the photo

Carry out preventive measures while preparing the soil for planting. Use chemicals for soil treatment - 2% Iprodione (use according to instructions), TMTD fungicide will disinfect the soil and seeds, prepare a suspension in equal parts of water and the drug, not compatible with drugs containing copper. 0.5% copper sulfate disinfects the soil (dilute 50 g of the substance in 10 liters of water).

Follow the rules to prevent fusarium onion:

disinfect planting material (potassium permanganate solution, Fitosporin)
use early and early ripening onion varieties
treat the soil before planting (the techniques are listed above)
alternate onion planting sites
loosen and weed the beds
harvest in a timely manner

The disease may appear after harvesting and spread to healthy bulbs, observe storage conditions - place the onions in wooden boxes, the room must be ventilated, constant temperature +5 ° C, air humidity 60%.

Preventive measures

Onion diseases often manifest themselves in late stages - after harvesting, when there is no point in treatment. Therefore, the main control measure becomes high-quality prevention.

Treating the site and onion seeds against diseases

In many cases, fungi and viruses attack onions at the planting stage. The problem may be contaminated soil or contaminated seeds. To avoid having to look for treatment methods later, before starting to grow a crop, you must:

dig up the selected area, remove all plant debris and spill the soil with a solution of potassium permanganate;
soak the planting material in a biological solution with fungicidal properties, for example, in the drug Trichodermin;
warm the sets or seeds at 40 °C for 12-24 hours.

To protect onions from diseases, it is necessary to thoroughly loosen the beds every autumn. In this case, fungal spores will be closer to the surface and die during severe frosts.

Agrotechnical techniques

You can protect your plantings from diseases and avoid complex treatment by following the basic rules of agricultural technology. When growing onions, several points are of particular importance:

Crop rotation. It is necessary to grow onions in areas where peas, tomatoes, potatoes, pumpkins, beans or early cabbage were previously located. The crop is transferred to a new corner of the garden annually, and returned to the old soil no earlier than after 3-4 seasons.
Choosing a location. The plant develops well and rarely requires treatment in lighted and well-ventilated beds without stagnant moisture.
Proper watering. Onions per feather are moistened up to twice a week, a bucket of water is added per 1 m2. If the summer is rainy, additional watering may not be necessary. Onions require frequent moistening only until July. In the second half of summer, the intensity of watering is reduced and the crop is allowed to ripen.

When growing onions, it is necessary to provide the plant with regular feeding. If there is a lack of nutrients in a crop, the immunity of the crop decreases, and fungal diseases that require treatment develop more often.

Onions in the garden should not be overfed, since an excess of microelements in the soil also provokes the activity of microorganisms

Other methods

It is usually not recommended to treat onions against diseases with chemicals - this method of treatment makes the crop unfit for consumption. However, to protect crops from fungi, you can use some biological products with a natural and safe composition. For example, it is allowed to add Fitosporin to water for irrigation at the rate of 15-30 ml per garden watering can. With regular weekly use, the drug will help prevent the development of fungi in the soil and help treat diseases in the earliest stages.

A good way to combat pathogenic microorganisms is to use green manure. The onion plot can be sown with mustard. During the growth process, it releases substances with antiseptic properties and prevents the spread of fungi.

Onions should be stored in a dark place at a temperature of about 5 °C. In such conditions, the crop is less likely to suffer from diseases, since microorganisms cannot develop comfortably.

Neck rot of onions

The disease is caused by a fungus that develops in unharvested, rotting plants in the garden, manifested by yellowing of the onion neck and subsequent spread to the plant’s bulb to the bottom. An unpleasant odor appears in the harvested crop, the head is loose, and when the bulb is cut, dark areas are visible at the base, sides or neck of the vegetable. Causes of the disease:

Neck rot of onions - pictured

excessive moisture and lack of sun
poor quality planting material
insufficient disinfestation of soil and raw materials
harvesting onions in rainy weather
insufficient feeding of the plant

At the first suspicion of a disease, you can use 1% Bordeaux mixture (dilute 100 g of the mixture in 10 liters). The drug Quadris is used both in the treatment of planting material and for the treatment of fungal diseases in the garden. Preparation: dilute 8 ml of the drug in 10 liters of water. Prevention of the appearance of cervical rot:

weed cutting
loosening the soil
harvesting ripe crops in dry weather
drying the bulbs for 7 days at +35° C (after collection)
storage in a disinfected room at +3° C and humidity not higher than 70%

Onion viral diseases

There are no effective treatments for diseases caused by viruses, so it is advisable to take preventative measures to avoid or reduce plant infection.

Mosaic

The causative agent of mosaic is Allium virus 1 Smith. Onions of the second year of growing season, grown for seeds, and multi-tiered onions are especially prone to mosaic infection, while leeks are not affected by the mosaic virus. The onion mosaic virus has natural resistance to high and low temperatures; it does not die even after treatment with pepsin.

Infection does not occur through diseased seeds or contaminated soil—the disease is carried by aphids. It takes approximately 7–10 days from infection to the appearance of external symptoms. The diseased plant is removed from the garden along with its roots and destroyed by fire.

Symptoms:

In diseased plants, green feathers change color to yellow. The leaves and arrows curl unnaturally, and small whitish spots and lines appear on the above-ground parts of the plant.
The onion stops growing, a little later the plant begins to wither and gradually dries out.
Ugly-shaped inflorescences appear on the testes; the ripened seeds will be small and there will be very few of them.

Yellow dwarfism

This disease is caused by a virus that can be transmitted by various species of aphids.

Symptoms:

The disease begins with the appearance of chlorotic and yellowish stripes at the base of old leaves.
Then spots appear on young leaves - from isolated grooves to complete yellowing, sometimes spiral twisting, folds and falling feathers appear.
The development of the virus causes the bulbs to shrink in size, reducing yield.

Important! Experienced gardeners recommend planting onions, alternating them through several rows with carrots. This method of planting protects both crops: the phytoncides emitted by carrots repel the onion fly, and the smell of onions repels carrot pests.

Wet bacterial rot and black rot

Caused by bacteria that damage an already harvested crop, but sometimes the plant becomes infected in the soil. Externally, the onion peel looks wet, then the inside becomes loose, sticky to the touch when pressed, moisture with an unpleasant odor is released.

Reasons for appearance:

increased soil moisture
contaminated soil
incorrect storage conditions
crop damaged during harvest and by insects

black rot of onions - in the photo

Prevention:

disinfection of planting material and soil
fight against onion fly, the vector of the disease
maintaining the integrity of the onion head
harvesting in dry weather
drying bulbs
compliance with storage rules (listed above)

To save the harvest in a rainy summer, experienced summer residents and gardeners recommend trampling onions before harvesting. Why, you ask? So that the bulbs do not become saturated with excess moisture and have the opportunity to ripen by the time the onion harvesting begins. If you pull out an onion, you will see that it is growing and is not going to ripen, while the feathers are green. So, two weeks before the expected harvest, walk along the bed and trample the onion in the neck area. Don't break it, just press it well to start the ripening process. After 14 days, your onion can be removed from the garden and not be afraid that it will rot.

General protection (prevention)

Onion diseases are usually not treated, or only in the initial stage. Therefore, preventive measures to combat diseases come to the fore. Here, agronomic techniques play an important role. For example, such as crop rotation, choosing a place for onions, fertilizing, weeding, loosening, proper watering, disease prevention. Later in the article, we will consider these points in more detail. Let's go?

Choosing a location in the garden and crop rotation

The place for the onions is usually chosen on the sunny side of the site. Also, make sure that there is no stagnation of water in this place (a swamp is not suitable). And also, pay attention to the acidity, which should be neutral (6.4 - 6.7 pH). In general, look for more detailed information about onions in this article

Crop rotation is also important. Here, you need to choose good predecessors. For example, onions grow well after crops such as pumpkin, zucchini, potatoes, beans, peas, early cabbage, and tomatoes. Important. We return to this bed to plant onions, no earlier than after 3 - 4 years.

On a note!
Onion plantings are compacted with carrots to repel the onion fly. And it works. But carrots, with their lush bushes, suppress onions, so we don’t particularly indulge in such compaction.

How to feed onions

Farmer hand with fertilizer for growing onion plants in the garden.
As we know, onion diseases usually attack weak plants; they are the ones most susceptible to infection. And to prevent this from happening, you need to feed the onions during the growing season.

On a note!
At the first signs of any disease, it is necessary to stop nitrogen fertilizing; here you will need to fertilize with potassium and phosphorus fertilizers or add ash. By the way, potassium increases plant resistance to disease. Nitrogen is needed only at the beginning of the growing season, to build up green mass.

First feeding

(2 weeks after germination, here we focus on fertilizers with nitrogen, because it helps to increase green mass).
You can read more about fertilizing here in the article
.

Second feeding

(3 weeks after the first feeding, emphasis on potassium-phosphorus fertilizers, for example, superphosphate, potassium salt, here you need to be more careful with nitrogen, because nitrogen is not particularly needed during the formation of bulbs).

Third feeding

(only necessary if the plant is not developing well, here we fertilize it with potassium-phosphorus fertilizers, the same as with 2nd feeding).

On a note!
In the fall, when preparing a place for planting onions, we fertilize with organic matter, and also in the spring. Here, it is important that there is no fresh manure. We use compost and humus for these purposes.

Processing seedlings in spring and autumn

Preparation

sowing begins in the fall, when we sort the bulbs by size. Here, 1.5 - 3 cm in diameter are selected separately, and smaller specimens go into another pile.

There are several options for processing seedlings before planting. For example, it can be soaked in hot water + 45 ° C - 50 ° C for 10 - 15 minutes. Alternatively, the sets can be heated at a temperature of 40 °C - 45 °C for 6 - 7 hours.

Also, the sets can be soaked in a saline solution (1 tbsp per 1 liter of water) for 3 - 5 minutes. Also, a solution where 250 g of ash is diluted in 5 liters of water is suitable, and here we soak for 5 - 7 minutes. And finally, the most popular method is soaking in a solution of potassium permanganate for 20 - 30 minutes.

Currently, it is fashionable to use various growth stimulants to prepare seedlings. For example, such as Zircon, Tsitovit, Biostin. Or biofungicides such as Planriz, Gamair, Fitosporin. The choice in stores is huge, so it’s up to you to choose.

Drying the crop

. Before storing, it is necessary to dry the bulbs well, otherwise the onions will not be stored. It should always be this way.

The harvest must be fully ripe

, otherwise, long-term storage is impossible. The disease mainly affects unripe, undried and injured fruits.

Optimal storage conditions

, here + 0 ° C - 5 ° C, with a humidity of 70 - 80% (this is important). With other indicators, the results will be worse.

Prevention

Preventive measures

It is better to control diseases and pests using folk remedies. For example, dusting with ash, tobacco dust or ground hot pepper.

Strong and not so strong, chemical preparations are not recommended. This is especially true about forcing green feathers. Here, chemicals cannot be used at all. Although, biofungicides and bio insecticides are considered quite safe for the health of both humans and plants. And if onions are grown for turnips, then you can also use chemicals. There are a lot of them in stores, it’s up to you to choose. The main thing here is to follow the instructions for the medications. For example, the drug Hom (suitable for mass infection).

Vegetable storage

must be prepared before storing. To do this, it can be treated with a sulfur bomb, desaktin or a lime mixture with the addition of copper sulfate. This is always done before adding (and not just onions).

With selective infection

We remove diseased plants from the garden bed (burn them), and where they grew, we spill the soil with a solution of potassium permanganate or a solution of copper sulfate.

Onion care (correct)

Onion diseases, with proper care, can avoid you. Therefore, we pay special attention to watering. This moment plays a key role. Because high humidity always promotes disease. And here, you need to water in moderation, while taking into account the region.

For example, onions are watered on greens 1-2 times a week, but onions on the head are watered only in the first half of summer, so we allow the onion to ripen. And if it rains, then problems with diseases cannot be avoided.

We also keep the garden clean, cultivate and loosen the soil. For example, it is advisable to carry out loosening after each watering or fertilizing.

Mosaic bow

The causative agent is a virus that infects the bulb and feather itself, expressed by the presence of light yellow spots, light green longitudinal lines on the stem, as well as curling and drying of the edge of the green part. The disease is serious and also affects garlic, so treatment must be carried out. The main sign of the appearance of a mosaic is considered to be different lengths of onion leaves, in other words, crumpledness, while the turnip does not develop.

bow mosaic - pictured

The reasons for the appearance are considered to be late planting, densely planted beds, and lack of control of aphids. Use insecticides for onions to eliminate aphids - Aktara affects the plant itself from the inside - dilute 8 g of the drug in 10 liters of water, if you have liquid, then 2 ml per 10 liters and water the beds. If you don’t want to use insecticides, prepare a wood ash tincture - boil 10 liters of water with 300 grams of wood ash for 30 minutes, let it cool and add 40 grams of grated laundry soap. Now you can spray the beds.

Prevention of onion mosaic is as follows:

maintain crop rotation
fight weeds
follow the watering schedule
fight insects

Treatment of onion plantings in case of diseases

When signs of fungal diseases appear, stop excessive watering and nitrogen fertilizing, sprinkle the beds with wood ash, loosen the soil well and destroy remaining weeds, and choose products for treating the plants. Chemical control agents can only be used in the first half of summer, and if onions are grown for feathers, it is advisable to refrain from them. In any case, before spraying with any preparations, it is worth pulling out the infected plants, if there are only a few of them.

In the initial stages of the disease, folk remedies can help. These are infusions and decoctions of various plants (dandelion, celandine, marigold) or tobacco dust. Planting plants such as marigolds, dill, hyssop and other fragrant herbs greatly reduces the risk of disease and repels pests. If only a few plants are sick, they should be pulled out and the holes in their place should be watered with a solution of potassium permanganate or copper sulfate (1%).

Marigolds are not only beautiful flowers, but also reliable protectors of the harvest.

If a fungal disease has affected a large number of plants, the entire bed is sprayed with copper preparations, for example, copper oxychloride (40 g per bucket of water) twice a week. However, leaves after this treatment should not be eaten for 3-4 weeks. Among other drugs, Aktara, Karate, Fitoverm, etc. are popular. They help fight insect pests that carry dangerous viruses.

Video: spraying onions against fungal diseases

Green moldy rot

The causative agent is a fungus that infects vegetables during storage, expressed by drying out of onion skins and the appearance of green (penicillium) mold on the bottom and side parts of turnips, most often appearing after the second or third month of storage. Causes of green moldy rot:

mechanical damage during harvest
high humidity in the room where onions are stored

Harvest carefully to avoid damaging the bulbs. You can use preparations against small pests (mice) to keep the vegetables intact. Maintain a temperature of +3° C and a humidity of 60% in the room where the onions are stored.

Now you know the most common onion diseases, descriptions and their treatment, good harvests to you!

Pests

Onion (root) mite

The mite is 0.7-1 mm long, oval-shaped, whitish-transparent. There are eight legs, their color is brown.

Mites persist in the soil of vegetable gardens, in plant debris, and on infected bulbs. It is carried with soil and planting material into areas free from it, into greenhouses. The tick is polyphagous. It damages the bulbs of garlic, onions, tulips, daffodils, snowdrops, hyacinths, irises, and dahlias. Harmful to potatoes. Plant debris can serve as food for it.

The mite causes damage to onions during the growing season and during onion storage. The mite penetrates the bulb through the bottom, through wounds. The damaged bottom of the bulb becomes flabby, crumbles, and sometimes falls off. The diseased plant is stunted and turns yellow. Settling between the fleshy scales of the onion, mites feed on them. Damaged scales become rotten and the bulb rots. Bulbs severely damaged by mites dry out during storage.

The mite is moisture-loving. It is noted that when the humidity is below 60%, the development of the mite stops, but it does not die, but only enters a stage resistant to dryness and starvation. As humidity increases, ticks again switch to an active lifestyle.

Females lay eggs in bulbs, preferring those that are damaged by other organisms. Each female lays up to 800 white oval eggs. The tick development cycle under normal conditions of temperature and humidity is completed in 20–25 days.

Control measures.

Maintaining crop rotation. Good predecessors of onions are tomatoes, cucumbers, cabbage.
Removing rotten bulbs and post-harvest residues from the garden.
Control of other onion pests that cause wounds to plants through which the mite penetrates the bulb.
Harvesting onions in dry weather and drying them in the sun until the leaves dry out.
Rejection and destruction of diseased bulbs when storing onions and during storage.
Selection for planting healthy bulbs that are not infected with mites and other pests and diseases.
Disinfection of onions before planting by heating at a temperature of +35... +37′ C for 5-7 days. This operation can be performed by placing a baking tray (box) with sowing material on the heating radiator.

Tobacco thrips

An insect with a narrow body, 0.5-1 mm long, dark brown in color. Thrips have two pairs of wings, they are narrow, fringed with a fringe of hairs. The larva is similar in appearance to an adult thrips, but is smaller and does not have wings.

Tripe damages onions, cabbage, cucumbers, tobacco, watermelons, tulips, carnations, gladioli, dahlias, lilies, daffodils and other plants. Harmful in open ground and in greenhouses. On onion plants, tripe settles in the axils of leaves and on inflorescences. Adult thrips and their larvae pierce the plant tissue with their proboscis and suck out the juice. At the injection sites, whitish spots appear on the leaves, which merge with each other if the damage is severe. Damaged leaves become distorted and, starting from the top, dry out. The development of the bulbs slows down, they remain small. When the number of thrips is high, onion inflorescences often dry out, and if they form seeds, they are puny and unsuitable for sowing.

Tripe develops in 3-4 generations per year. Adult thrips overwinter in plant debris, in soil and under dry bulb scales. In early spring, thrips feed on weeds, then move on to vegetable and flower crops. Females lay eggs one at a time in leaf tissue. The egg stage lasts 5-6 days. The development of one generation is completed in 15-30 days. In autumn, thrips go to their wintering grounds. Often thrips crawl under the dry scales of the bulbs and end up with them in storage. It is noted (B.A. Gerasimov et al., 1961) that on onion sets, thrips, located between dry and fleshy scales, feed and reproduce all winter.

Control measures. Proper crop rotation: return onions to the same place no earlier than after 3-4 years. Cleaning up plant residues from the garden. Deep digging of the soil in the fall with embedding of plant remains. Warming up onion sets infested with thrips at a temperature of +42... +43° C for two days or warming up the sets before planting in hot water at a temperature of +45° C for 10 minutes, at +50° C for 5 minutes. After warming up, the sets are cooled in cold water.

Onion leaf miner

A black fly with a yellow head and antennae, its body length is 2-2.5 mm. The larva is whitish, up to 6 mm long.

The fly damages onions, often grown from turnip sets, and onion seeds. Onions of the first year of life, sown with seeds, are little damaged.

Fly pupae overwinter in the soil in areas that have come out from under the onions. Flies emerge in May. The fly lays eggs one or several at a time on the inner wall of the leaf, after piercing it with the ovipositor. The larvae eat away the pulp of the leaves from the inside in the form of small irregularly shaped areas. The integrity of the outer skin of the leaf is not compromised. From the outside, mines appear as whitish spots. The feeding of several larvae in the leaf causes it to dry out.

The fly develops quickly: the egg stage lasts 4-5 days, the larvae - up to 15 days. The larva, having finished feeding, leaves the leaf and goes into the soil to pupate. Adult flies feed on the juice of onion leaves. To do this, they prick a leaf with the ovipositor and lick the juice protruding from the wound. At the injection site, a small spot, like a dot, forms, clearly visible against the green background of the leaf.

Control measures. Maintain crop rotation and avoid re-planting onions in one place. Avoid, if possible, the proximity between the old and new sections of the onion. Deep digging of the soil after harvesting onions.

Onion fly

Damages onions and sometimes garlic. Onion seedlings, onion sets and onions intended for seeds suffer from flies. More significant damage is caused by continuous cultivation of onions.

The fly is ash-gray with black legs, its body length is 6-7 mm. The larva is up to 10 mm long, whitish, its body is narrow at the anterior end. At the posterior end of the larva there are 16 tubercles.

The fly develops in two generations per year. The pupae overwinter in the soil at a depth of 15–20 cm. In the spring, the flies emerge in early May. The year of the flies coincides with the cherry blossoms. Flies first feed on the nectar of flowers, then begin laying eggs. The female lays several white oblong eggs on the neck of the onion, between the leaves, under lumps of soil near the plants. Egg development lasts 3-8 days. The larvae penetrate the bulb through the bottom or through the base of the leaves. While feeding inside the bulb, they make numerous passages.

Damaged bulbs rot, leaves turn yellow, and the entire plant is easily pulled out. The development of the larva lasts 20-25 days. Having finished feeding, the larva goes into the soil, where it pupates, and after 15-20 days the second generation flies hatch from the pupae.

Control measures. If possible, sow and plant onions as early as possible. Plants that are stronger by the time the fly larvae hatch are less damaged. Late crops are more damaged by flies.

Placing onions next to carrot beds. Substances (phytoncides) secreted by carrots repel onion flies, and onion phytoncides repel carrot pests. In order to repel flies, at the beginning of their egg laying, the soil along the rows is sprinkled twice (with an interval of 7 days) with tobacco dust or a mixture of tobacco dust and lime (in a 1:1 ratio).

Repeated inspection of onion plantings in order to remove and subsequently destroy plants damaged by fly larvae.

Collection and destruction of post-harvest residues.

Deep digging of the soil after harvesting onions and garlic.

Onion hoverfly

The fly is metallic green in color, with three pairs of narrow light spots on the sides of its abdomen. The body length of the fly is 7-9 mm. The larvae are grayish-yellow, wrinkled, at the posterior end with a process in the form of a short tube. The length of the larva is up to 11 mm.

The fly damages, in addition to onions and garlic, tulips, daffodils, irises, gladioli, sometimes underground parts of carrots, beets, potatoes. Potato, or tuberous nightshade (from the Latin Solánum tuberósum), is a species of perennial to...

The fly develops in two generations per year. The larvae overwinter in bulbs in the field, rarely in storage. Pupae can overwinter. Flies fly out in early June. Females lay eggs in groups of 5-9 pieces on the soil near plants or on bulbs. The larvae penetrate the bulb, live in it for 25-30 days, then go into the soil to pupate. The second generation flies emerge in July-August. Their larvae cause damage in August-September.

The larvae, feeding on the bulb, destroy it. The inside of the onion completely turns into a rotting mass.

Control measures. The same as with the onion fly. In addition, the following actions are necessary: planting onions with bulbs that are not infected with hoverflies; careful control of wireworms, onion flies and other pests, since hoverfly larvae often colonize already damaged bulbs.

Onion moth

The moth is a dark brown butterfly with a wingspan of 8-10 mm. On the front wings of the butterfly there are white transverse stripes, the hind wings are narrow, with a long fringe. The caterpillars are yellowish-green, 10 mm long.

Moths damage onions and garlic. Develops in two generations. Pupae overwinter in plant debris, and butterflies overwinter in crevices of buildings and other shelters. In spring, in May, butterflies emerge from overwintered pupae. They are nocturnal and sit unnoticed on plants during the day. Females lay eggs one at a time on the leaves, on the neck of the bulb, on the flower shoots. The caterpillars first mine the leaves. Later, they penetrate inside the tubular leaves and eat away the pulp in their walls in the form of winding strips, without touching the outer skin. Damaged leaves turn yellow and die. The onion harvest is decreasing. On onion seeds, caterpillars eat away the flower buds of inflorescences that have not yet bloomed.

The caterpillar stage lasts 15-16 days. Having completed feeding, the caterpillars leave the leaves and arrows of the onion. On onion plants, on weeds, on the soil, they weave cocoons and turn into pupae in them. The second generation butterflies emerge in July.

Control measures. Maintaining the order of rotation* of crops on the site. Creating favorable conditions for the growth and development of onions (loosening the soil, watering, weed control, etc.). Developed plants suffer less from moths. Deep digging of soil in areas exposed to onions. Thorough incorporation of plant residues with soil.

Onion leaf beetle

The beetle is elongated-oval. Its elytra are orange-red, its abdomen is black, and its legs are red. The length of the beetle is 6-7 mm. The larva is dirty gray in color, its head and legs are black.

The leaf beetle damages onions, garlic, as well as lilies, lilies of the valley and other lilies.

The leaf beetle produces two generations per year. The beetles hibernate. They leave their wintering grounds at the end of April. At first they feed on wild plants from the lily family, later they switch to the leaves of cultivated onions and gnaw holes in them.

The female lays orange, elongated eggs on the leaves in groups of 3-20 eggs. The larvae eat holes in the leaves. On onion seed crops, the larvae eat the flowers and ovaries. Having completed development, the larvae go into the soil to pupate.

Control measures. There are no special measures to combat the leaf beetle. Digging the soil in the fall, controlling weeds in gardens and adjacent lands, and taking good care of onion plantings help reduce the number of leaf beetles and increase the resistance of onions to damage.

Onion sneaker

A beetle from the weevil family. Its body is oval-convex, black, covered with gray scales, its head is elongated into a tube, bent down. The length of the beetle reaches 2-2.7 mm. The larvae are legless, yellowish, up to 6.5 mm long.

Damages the bow. Beetles overwinter under plant debris along roadsides, ravine slopes, on uncultivated soddy lands adjacent to vegetable gardens, under lumps of soil. The beetles emerge from their wintering grounds in mid-April. At first, the beetles feed on the leaves of sprouted bulbs left in the ground after harvesting, on the early-growing perennial onion. With the emergence of seedlings and the growth of planted bulbs, beetles begin to damage the cultivated onions. They gnaw small holes in the leaves and eat away cavities in the pulp of the leaf from the inside. Damaged leaves become distorted and dry out. The beetle causes the greatest damage to onion seedlings, causing the death of damaged plants.

Females begin laying eggs at the end of April. Through the holes they gnaw, they lay eggs on the inner walls of tubular leaves. The larvae eat away the pulp of the leaf in the form of longitudinal strips, leaving the outer skin intact. Damaged leaves turn yellow and dry out. Several beetle larvae can live in one onion leaf. The larvae feed on the leaf for 15-20 days. Having finished feeding, they go into the soil, where they pupate at a depth of 3-5 cm. Young beetles appear at the end of June. They feed on onion seeds, gnaw the stalks and thereby reduce the yield of seeds. After harvesting the onions, the beetles fly to their wintering areas.

Control measures. Collection and destruction of beetles from onion. Cutting and destroying damaged leaves that may contain beetle larvae. Loosening the soil between rows during the period of pupation of larvae. Cleaning up plant residues and onion waste. Digging the soil in the fall. To protect onions from the secretive proboscis, it is sometimes recommended to spray plants with tobacco infusion or decoction, lye and soap. To make lye, 200 g of ash is poured with hot water (10 l), left for 24 hours, filtered and 50 g of soap is added.

Onion sharpener

A little-studied pest of onions and garlic. Currently known only in the Rostov region and Krasnodar region.

The wingspan of the butterfly is 23-26 mm. Her body is covered in thick hairs; light brown forewings with a brown pattern, hind wings with variegated fringe. The caterpillar is flat, reddish above, yellowish below, up to 24 mm long.

It is known that caterpillars overwinter in the soil. Pupation and emergence of butterflies occurs in the spring. The caterpillars gnaw inside the bulbs and eat away large cavities in them. Together with the heads of garlic, the caterpillars can be brought into storage and there they can feed and pupate,

Control measures. Not developed. It is recommended to cull damaged bulbs.

Potato cutworms also gnaw out cavities in garlic and onion bulbs.

Onion stem nematode

The nematode is a thin thread-like worm 1-mm long, whitish in color. In the oral cavity of the nematode there is a stylet, hollow inside, in the form of a needle, which serves to pierce the plant tissue and suck out the contents. The nematode damages onions and garlic, sometimes parsley, parsnips, tomatoes, radishes, and lives on weeds.

The nematode overwinters in bulbs and in the soil, in onion seeds. On onion scales, the nematode remains dormant for up to two years, and in dried garlic cloves for up to 5 years. In spring, the nematode penetrates from the soil into plants, most often through the bottom of the bulb, and less often through stomata in the leaves. The nematode lays eggs in the tissue of leaves, stems and bulbs. Infected bulbs planted in the soil produce diseased, non-viable plants. Onion seedlings become infected soon after their appearance.

Affected plants are stunted in growth, their leaves become distorted, and plants often die. In plants infected with the nematode at a later age, the external signs of the disease are not clearly expressed. But their bulbs become loose, soft, and the bottoms crack. Cavities form between the juicy scales, and the bulb seems soft to the touch. The destruction of the bulbs continues during storage.

Control measures. Maintain crop rotation. Onions and garlic are planted in their original place no earlier than after 3-4 years.

Sowing and planting onions is recommended in the early stages. Disinfection of onion sets is carried out by soaking in water at a temperature of +48... +50° C for three days. Garlic is not soaked in water: when planted with cloves in the fall, it does not tolerate winter well.

Black onions are disinfected by immersing them first in cold water for 4 hours, then in water with a temperature of +48 ... +50 ° C for 10 minutes. After this, the water is drained and the seeds are cooled in cold water.

Culling and destruction of diseased plants during the growing season.

Fusarium

Among the dangerous diseases of onions is fusarium, which causes the bulbs to rot and the leaves to die. The causative agent of the disease is located in the soil and becomes active in the spring after the soil warms up. First, due to fusarium blight, the leaves darken, and then spotting appears on the fruits. The bulbs become softer, a grayish coating appears on their surface with an unpleasant smell of rot.

The reasons for the appearance of the first signs of pathology include:

too frequent watering of the area where onions are grown;
late harvest of ripened fruits;
use of spoiled seed;
high air temperature.

In order not to encounter plants affected by fusarium in the future, it is necessary to take preventive measures in advance. Preventive measures are taken at the stage of preliminary soil preparation for planting onions. Before planting, the entire area is treated with a solution of the drug Iprodione, which completely disinfects the soil and cleans it of bacteria. Also, when growing onion seedlings, you must adhere to the following preventive measures:

regular loosening of the site;
planting only early-ripening varieties;
pre-sowing disinfection of planting material with manganese solution;
compliance with harvest deadlines.

To prevent fusarium from appearing after harvesting the bulbs, all fruits are stored in rooms with a temperature no higher than five degrees Celsius and a humidity of about 50%.

Black mold rot

The appearance of mold rot is promoted by onion pests and dangerous bacteria that affect already harvested fruits. It is possible to determine that the bushes are infected with this disease only after digging up the crop. The development of the disease is indicated by darkening of the surface of the onion. Also, infected heads become soft and gradually rot. Black mold with a musty and unpleasant odor forms on their surface. The main reasons for the development of pathology include:

storing crops in unsuitable premises;
serious damage to onion heads;
presence of bacteria in the soil;
soil is too wet.

To preserve the crop and protect it from infection with black rot, all rows are trampled down before harvesting the fruits. This will protect the plant from excess moisture and stop the development of bacteria in the soil. You need to trample the bushes very carefully so as not to accidentally damage them. Also for prevention it is necessary:

promptly get rid of the onion fly, due to which the bushes can become infected with rot;
remove the onion only on sunny days;
dry fruits before storing;
pre-disinfect seed material;
create suitable conditions for storing fruits.

Mosaic

Mosaic - in diseased bushes, the foliage becomes similar to corrugated and flat flaps, on the surface of which there are stripes of yellow color; smaller inflorescences and a decrease in the number of seeds are also observed, as well as stunted growth of onions. This viral disease is incurable, so all necessary preventive measures should be taken to prevent the plant from becoming infected.

All fungal diseases are easily treated with fungicidal drugs. However, it should be taken into account that both beneficial substances and poisons from chemicals can accumulate in the bulbs.

Treatment options

To treat onion diseases, you can use common folk remedies or proven methods using specialized drugs. The main folk method is to artificially accelerate the ripening process by increasing potassium-phosphorus fertilizers. Feeding will lead to rapid development and closure of the neck of the bulb before infection occurs.

You can also combat the symptoms of seedling disease in the following ways:

when watering, add table salt to the water every 2-3 weeks in a ratio of 300 g per 10 liters of liquid;
sprinkle the surface of the beds with wood ash or a mixture of slaked lime and tobacco dust;
throughout the entire period of crop growth, loosen the soil and conduct a visual inspection to detect and eliminate weeds;
use fungicidal drugs to combat the causative fungus and infections.

Onion jaundice

Onion jaundice is a viral disease. The affected plant has deformed flowers, and chlorotic spots appear on its foliage. This disease is incurable, therefore the affected bushes must be dug up and burned, while all weeds must be promptly removed from the rows and beds immediately after they appear. You also need to adhere to the rules of crop rotation.

White rot

White rot - its development is observed when grown in acidic soil. Therefore, if the soil on the site is acidic, it must be limed. It also often affects those plants that grow in soil with a high nitrogen content. Diseased plants need to be dug up and destroyed, and for preventive purposes, before planting the crop, it is necessary to dust the bulbs with chalk.