What are the diseases and pests of onions and how to deal with them

How to recognize a pest

Diseases can affect both the plants in the garden and the bulbs during storage. Signs of illness may include discoloration or spotting of feathers. Including, diseases include drying of the aerial part, the softness of the bulbs or the appearance of white, grayish or black bloom on them.

Onion fly

Very similar to a common fly. Larvae pose a danger to onions.
The onion fly comes out of hibernation around mid-May, and lays eggs in early June. The larvae hatch on the fifth or tenth day, penetrate into young bulbs and eat them from the inside.

The feathers of the affected plants turn yellow and dry, starting from the tips, the bulb itself rots. One larva per month of growth can damage an entire garden bed. After a month, the larva pupates, and soon a new generation of flies appears.

The fight against this pest begins with prevention. After harvesting the onion, you need to carefully sort it out and remove all damaged bulbs. Dry the remaining onion. In the spring, before planting, sort the bulbs again and again select the damaged ones.

It is strongly not recommended to plant onions in the same area for two years in a row. In fact, the correct crop rotation of onions involves the return of planting to the same place no earlier than in the fourth or fifth year, it is good to sow onions and garlic in the place where cabbage, nightshade or pumpkin crops were last year. The onion fly hibernates at a depth of up to 20 centimeters, so in the fall, the beds need to be dug deeply and all plant debris must be removed.

The onion fly does not like the smell of carrots, so it is advisable to plant onions and carrots (or garlic and carrots) in the same bed, alternating rows. Before planting, the onion sets must be disinfected in hot water. To do this, hold it in water at a temperature of 45-46 degrees, for ten to a maximum of fifteen minutes.

The onion fly is afraid of salt. You can process the beds two or three times per season. The first treatment is carried out when the seedlings are about 5 cm. For each subsequent treatment, the amount of salt must be increased. The first ratio is 300 grams per 10 liters, then 400 grams and, if the treatment is carried out for the third time, 600 grams of salt.

The beds (the plants themselves) need to be watered with saline, and after four to five rinse with plenty of clean water. The interval between treatments is about two weeks. Within a week after the flight of an onion fly, you can process the aisles of onion plantings with a mixture of tobacco dust and sunflower ash. Lime or ammonium carbonate is also allowed.

Video "Recommendations for onion pest control"

Useful tips for killing pests and treating diseases of green onions and garlic.

Lurker

The onion lurker, also known as the weevil, is a small beetle of dark gray or black color. Both beetles and larvae are dangerous for the plant. The body of the beetle is up to 2.5-2.7 mm long, with a characteristic proboscis bent downwards. The larva is a yellowish caterpillar with a brown head, 6-6.5 mm long.The pest feeds on the pulp of the leaves, which is why white dots or stripes appear on it.

Particularly affected leaves dry up. Despite the fact that the secretive proboscis does not directly harm the bulb. Due to the damage done to the green part of the plant, the onion yield in the infected area is significantly reduced.

The lurker begins activity quite early - in mid-April, and feeds on initially unharvested remains or sprouted onions. In late April or early May, females lay eggs inside the tubular onion leaves. After a week or two, the hatched larvae migrate to the leaves.

The larvae actively feed on the pulp of the leaves, and after three weeks they go out into the soil and pupate. This usually happens in July. A new generation of beetles appears in the same summer and continues to feed on the leaves and inflorescences of onions. And the fight against this pest is primarily based on crop rotation.

A new planting of onions must be placed in a place as far as possible from the previous planting, and always carefully remove all residues and waste of onions. Further, at the time of pupation of the larvae, it is necessary to regularly loosen the aisles of the onions to a depth of 5-10 centimeters. This is necessary so that the maximum number of pupae of the lurking proboscis is on the surface of the soil and perishes.

As a bait for the lurker, the crops of the onion can be used. They can be placed next to a regular bow, and then destroy the batun beds along with the pests. It is advisable to do this at the stage of the first white stripes on the leaves.

This is very important, since during this period the larvae are just beginning to grow and do not have time to infect the soil with pupae. A mixture of tobacco dust and wood ash scares off the lurker well. To do this, it is necessary in a ratio of 1 to 2, sprinkle the plants themselves after watering), tansy and celandine (sprinkling with dry powder or spraying plants with decoction).

Threesomes

Thrips or thrips represent a whole group of pests. These insects are small in size (on average, the body of an adult is up to 1 mm in length) of a discreet color, mainly herbivorous. Unlike the previous two, thrips are not only pests of onions and garlic, but also cabbage, cucumbers, tomatoes, potatoes, ornamental and even indoor plants.

Thrips are fertile and develop rapidly; per season they can give from 3 generations in the open field and up to 8 in greenhouses. The larvae of thrips suck the juice from the vegetative parts of the plants. With their significant damage, the stem is bent, the bulb softens, the plant stagnates and does not produce seeds.

The most dangerous for onions are tobacco thrips and onion thrips. Measures to combat them are the destruction of the food base and individuals in the soil at rest. This means that in the fall, you need to carefully dig up the beds, to a depth of 15-20 centimeters (the bulk of thrips hibernate at a depth of 5-7 centimeters) and remove as much as possible any plant debris and roots that can serve as food for the pest. The greenhouse after harvest can be treated with 0.15% karbofos.

In summer, deep loosening of the onion spacing is effective in order to destroy the pupae of thrips. Also, to protect onions from thrips, it is recommended to maintain a crop rotation and not plant onions next to other crops that are the fodder base of the pest: cucumbers, cabbage, tomatoes. For small lesions, it is effective to spray plants with decoctions of odorous and caustic herbs of celandine, tobacco, mustard, and hot pepper.

To do this, you can take 1 kg of fresh hot pepper and boil in 10 liters of water for an hour. Then insist for a day and pour into dark bottles. Before use, 125 ml of pepper concentrate is diluted in 10 liters of water and sprayed with this solution. The treatment is repeated at intervals of two weeks.

Winter crops and potato scoops

Scoops are small (up to 4.5 cm in wingspan), inconspicuous butterfly shades, which are universal pests. The caterpillars of the scoop affect the plantings of various types of cabbage, potatoes, tomatoes, onions, carrots - in fact, all garden crops, and both aerial parts of plants and roots are used for food. In late August-September, female moths lay eggs.

Caterpillars emerge from overwintered eggs in late April-early May, which begin to actively feed on both cultivated and weed plants. Caterpillars pupate no later than mid-July, in the soil, at a depth of 6-10 cm. After a while, butterflies emerge from the pupae and lay new eggs.

Based on such a life cycle of scoops, the fight against them, first of all, consists in thorough digging and loosening of the soil. This is done in order to kill as many eggs and pupae as possible by removing weeds. Because they allow caterpillars to saturate before active growth of cultivated plants.

From well-known folk remedies against scoops, you can apply a decoction of wormwood. It is necessary to boil 1 kg of grass in a volume of 3 liters of water for 15 minutes. Processing is carried out twice, with a break of a week.

An infusion of white mustard is also suitable. For preparation, you need to insist 2 grams of powder in a glass of water for two days, then strain and dilute with plain water to a volume of 1 liter). Unfortunately, such a pest as the winter moth is quite aggressive, and in case of significant damage to the plantings, industrial insecticides of wide action may be needed.

Bow protection tips

Thus, the optimal protection of onions and garlic from pests will be:

• complex wrestling throughout the season;
• observance of crop rotation (thus, pests of onions and garlic remain without a forage base for the next season);
• deep digging of the soil in the fall, with the removal of plant residues and weed roots;
• destruction of plant parts infected with pests;
• thorough drying of the seedling onion and checking it before planting;
• loosening the beds of onions and garlic to a depth of at least 10 cm several times per season, which makes it possible to destroy a significant part of the pupae;
• processing plants with various infusions of herbs and spices that repel insects;
• processing plantings with a solution of ordinary table salt;
• use of tobacco dust. This adjuvant is sold in specialized stores and, when used in the beds, disorients pests by interrupting the smell of plants;
• in the event of an excessive appearance of pests, it will be necessary to use agrochemistry.

Video "How to deal with onion diseases"

Useful tips for eliminating the cause of the appearance of yellow feathers in onions, its treatment and prevention of pests.