Why do onions turn yellow in the garden and what to do, what to water and feed, how to fight?

Failure to comply with agricultural practices and ignoring preventive measures becomes the main reason why onions may turn yellow. Either complete or partial yellowing of the leaves is observed. At the same time, they look lethargic and weakened. The situation may threaten a complete loss of the onion harvest.

Insufficient nitrogen content in the soil

A common reason why onions turn yellow is a lack of nitrogen in the soil. Its deficiency usually develops when the soil is depleted or in hot weather. Onion roots receive nitrogen only in dissolved form, and in dry weather it stops reaching the plants. On the contrary, excessive soil moisture or frequent rain can lead to leaching of nutrients from the soil.

With a lack of nitrogen in the soil, the plant slows down its growth, the feathers become short and thick. First, the color of the lower leaves becomes pale green, and then the young feathers turn completely yellow. A lack of nitrogen can also lead to bottom rot.

To prevent a lack of nutrients in the soil, it is necessary to fertilize in a timely manner. A solution based on urea or ammonium nitrate and an infusion of manure is suitable. The components must be dissolved in water so as not to burn the roots. The procedure can be repeated after 5–6 days.

Influence of pests

Onions often turn yellow as a result of pest attack. They not only suck the juices from the plant and gnaw on the greens and roots, but also carry various infectious diseases.

Why are onion moths dangerous?

The onion moth is a small butterfly (body length about 8 mm) of a dark brown color with light gray wings. At the end of spring, females begin to lay eggs at night on the soil near the bulbs or between the leaves. After 7–8 days, yellow-green caterpillars emerge from the eggs, 1 cm long.

Great damage from insects is observed, especially in dry, hot weather. The leaves begin to turn yellow and dry out at the tips, and light spots may appear.

What to do if the onions in the beds turn yellow due to the activity of onion moths? The effect of drugs such as Iskra, Dachnik, Metaphos is effective. Treating the soil with wood ash and tobacco dust helps repel pests. Sevok should be sown as early as possible. It is recommended to remove all plant debris from the site in the fall and dig up the soil before the onset of frost.

Onion thrips

Onion thrips is a small yellowish insect, about 1 mm long. It sucks the juices out of the plant, causing the onion feathers to turn yellow and dry out. The female lays eggs in the leaves, from which gray-yellow-green larvae emerge after 5–6 days.

Thrips, like onion moths, overwinter in the soil, burrowing into the remains of vegetation or in bulbs that are intended for sowing. Therefore, a preventive measure is to dig up the site in the autumn, apply fertilizers and clear away the remaining tops. Before planting, the sets must be disinfected by placing them, for example, in a weak solution of potassium permanganate or immersing them in hot water (water temperature about 45 degrees) for 10 minutes. If a pest is detected in the garden bed, it is treated with insecticides (Iskra, Konfidor).

Onion fly and how to destroy it

The most common pest of onions is onion fly, which affects any of its varieties. It resembles an ordinary fly, the body length reaches 8 mm, the color is gray-yellow.

In mid-May, when dandelion and lilac begin to bloom, the female of this insect begins to lay eggs in the soil near the onion beds, less often between young leaves or between dry scales of the bulb. After just 6 days, the larvae that emerge from the eggs begin to eat the bulb from the bottom.The feathers begin to become covered with yellow spots, and soon the entire plant dies.

The larvae develop within three weeks. They then burrow into the ground and pupate. After some time, new individuals appear, approximately at the end of July.

Preventive measures are:

• early planting of onions;
• it is recommended to plant carrots in the neighborhood;
• during the summer, flies in the beds are treated with a mixture of wood ash, tobacco dust and ground pepper;
• The drug Bazudin, which is mixed with sand and added to the soil, helps repel insects.

If the larvae have already begun their destructive activity, treatment with the drugs Kreotsid, Muhoed, Aktara, Karate Zeon. Treating onions with a saline solution with a few drops of ammonia is effective (200 g of salt should be dissolved in 10 liters of water).

Stem nematode

Stem nematodes, like onion flies, lead to yellowing of leaves and loss of yield. The nematode resembles a small worm (1.5 mm in length) that penetrates the bottom of the onion. Insects feed on the sap of the plant. The bulb begins to rot. White dots and stripes appear on the feathers, then the onion leaves turn yellow, curl and dry out.

It is difficult to fight the nematode, so the only thing that can be done is to follow some rules:

• treat planting material with saline solution or hot water;
• It is recommended to plant onions in the same area no earlier than after 4 years;
• You can plant marigolds between the rows; an infusion of these flowers also helps;
• Timely weeding should be carried out.

If the onions in the garden have turned yellow due to pests remaining in the soil, then the row spacing can be watered with a solution based on Fitoverm or Akarina powder.The drugs are toxic, so it is not recommended to use them too often.

The secretive weevil and the fight against it

The small-sized secretive beetle feeds on green onion leaves. Its body is gray and oval in shape. In spring they begin to eat young shoots. After laying eggs, beetle larvae appear within 2 weeks and begin to eat the greens. The larvae are yellowish in color with a brown head, about 6 mm long. First, white spots appear on the leaves, and then the onion feather in the garden turns yellow and dries out.

Preventive measures are:

• digging the soil in the fall after harvesting;
• clearing the area of ​​plant debris and weeds in the fall;
• It is recommended to plant onions annually in a new place.

If this insect appears in the beds, you need to loosen the rows with the addition of tobacco dust, wood ash or ground pepper. If there are not too many pests, you can collect them manually. Spraying with a solution based on the drug Karbofos helps destroy pests.

What is wrong with onions?

Onions turn yellow not only due to the invasion of insect pests. Very often, fungal, bacterial and viral infections can spoil the harvest.

Rust

Rust is a fungal disease of onions. It affects green leaves, resulting in insufficient nutrients reaching the bulb, and the yield is reduced.

First, yellow-brown stripes or spots appear on the leaves, which grow over time. The disease leads to complete yellowing and drying out of the green part of the onion.

Preventive measures mainly concern planting material, which needs to be heated and disinfected. If a problem is detected, the onion beds are sprayed with a solution based on copper oxychloride.The component is diluted in a bucket of water and 30 ml of liquid soap is added. Can be used drug Hom or Metronidazole.

Bulb rot caused by bacteria

Bulb rot can only be noticed on the harvested crop. The affected heads soften and dark stripes can be found between the scales. Such bulbs cannot be stored. This onion disease carried by insects.

Only healthy, dense bulbs are selected for planting. The soil is treated with Hom or Metronidazole. If you plant an affected seedling, the plant will grow weak. Young leaves immediately turn yellow and dry out.

Fusarium, bottom rot

All varieties of onions can suffer from a fungal disease such as fusarium. First, the onion feathers turn yellow, curl, and then dry out completely and the plant dies. On the bottom and in the axils of the leaves you can notice a white or light pink coating.

The following actions can be used to prevent damage to the bottom rot:

• the area for planting onions should be on a hill and well lit;
• You should not plant onions in the same area for several years in a row; grain crops are considered the best predecessors;
• you need to plant vegetables and harvest on time;
• seeds are selected and disinfected before planting.

When the first signs of the disease appear, treatment with Fitosporin and Quadris will help.

Alternaria blight

Another fungal disease that affects onions is Alternaria. Green feathers are affected first. They develop white spots that turn brown over time. Gradually, the disease spreads to the bulb, it becomes covered with black mold and rots.

Such preparations as Acrobat, Cabrio Duo, Polyram, Fitosporin will help save onions from yellowing of the feathers. In the fall, after harvesting, all tops and husks are removed from the garden.

Failure to follow the rules of onion care leads to yellowing of the feather

If you do not properly care for vegetable plantings, they become weak, lethargic and the leaves change color. Watering and fertilizing must be carried out in a timely manner and in certain quantities.

Insufficient or improper watering

At watering the onion head correctly it is formed dense, juicy and stored for a long time. In the first days, when the onion is just taking root, you need to water it generously every three days. Then watering is reduced to once a week. In July, when the head is forming, it is enough to water once every 1.5 weeks.

Water for irrigation should be warm (about 20 degrees) and it is better to pour it under the root. The best time for watering is considered to be early morning or evening hours. If the weather is cloudy, then it is possible at lunchtime.

Onions love moist soil, but excess moisture can lead to stunted growth due to leaching of micronutrients, rotting and the spread of infections. In addition, the onion head is small and tasteless.

Another reason why, under normal plant care conditions, the leaves turn yellow is weather conditions. Return of frost, drought or heavy rains can affect the quality and quantity of the harvest.

Lack of feeding

It is recommended to fertilize during watering. The first application of fertilizers is carried out two weeks after planting. You can make a solution from ammonium nitrate, superphosphate and potassium salt. The next application of fertilizing is carried out after another two weeks.

What to do?

There are many ways to deal with onions that turn yellow, dry out and die. The main thing is to recognize the cause in time.

Folk remedies for yellowing feathers

If pests are the cause of the yellowing of the onions, then folk remedies will help:

• One ampoule of ammonia, 200 g of ordinary table salt and 200 g of wood ash are dissolved in 10 liters of water. It is recommended to water the beds with the resulting solution after 10 days, until the leaves turn green again.
• Dissolve 1 kg of soda, 10 ml of iodine and 4 bags of potassium permanganate in a bucket of water. The finished concentrate is diluted with water in a 1:1 ratio and the beds are watered. The solution is enough for a large planting area.
• Plant infusions are prepared from dandelions, wormwood, calendula, and hot pepper.

As a preventive measure, you can water the rows with salt water or sprinkle them with a dry mixture of tobacco dust, wood ash and ground pepper.

Chemical plant protection products

In the event of a mass attack of pests, due to which the onions have turned yellow, chemical spraying is carried out. Among the popular and effective: Mostilan, Iskra, Aktara, Karbofos, Leptotsid, Kreotsid.

To prevent onions from turning yellow, you can prevent a lack of nitrogen in the soil by adding urea or ammonium nitrate. Between the rows of onions, grooves are dug and 6 grams of ammonium nitrate per 1 square meter is poured. m.

Simple tips for caring for onions

How to water the beds to effectively combat yellowing of leaves? Most vegetable growers use salted water. A mixture of wood ash and carrot seed powder gives a good effect. You can treat the beds with wood ash or chamomile pollination. If the onion turns yellow, you can feed it with complex fertilizer.