Leek maggots affect yield, under what conditions are leek maggots more common?

Leek maggots affect yield, under what conditions are leek maggots more common? The host of allium maggots is leeks, green onions, garlic, flowers, and Chinese medicinal herbs. The larvae swarm on the leaf sheaths and bulbs of the underground part of the leek, and the symptoms generally appear from the outside after the occurrence of leeks, and the outer leaves turn yellow in the early stage, and then the whole leaf and the whole plant turn yellow until the leek dies.

Leek maggots can damage multiple times in a year. One is called after the rain to Qingming hazards"Spring maggots"At this time, the soil begins to thaw, which mainly harms the germination of leek sprouts, often makes leeks unable to germinate in spring, resulting in lack of seedlings and ridges, and the serious harm is more than 70%. In severe cases, large clumps of plants die.

Its harm is that when the white dew reaches the autumnal equinox, it becomes"Autumn maggots"Once the leeks are harmed by the autumn maggots, the leek plants will die and cannot sprout, although some can sprout, but because of the heavy weight, the seedlings that grow are very thin, and the classic 1 2 years of fertilization ability can resume normal growth. Generally speaking, in terms of the degree of harm, spring maggots and maggots are the most serious. Spring maggots begin to damage around the time of the rainy season, and the most harmful parts are the base of the leaf sheath and the top of the bulb.

Maggots begin to harm around early summer, the damage is light, and it aggravates in the small full season, so it is called maggots, and generally harms the lower half of the leaf tip. During this period, it is hot and rainy, and the parasitic maggots are mainly in the upper half of the leaf tip, that is, near the surface. In order to control leek maggots, vegetable farmers often use a large number of pesticides, and even use and ban highly toxic pesticides, resulting in high pesticide residues in leeks, which seriously affects the quality of leeks"Poisonous leeks"Incidents occur frequently.

Leeks are a very popular vegetable, and their pollution-free cultivation has attracted more and more attention.

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Methods of control of leek maggots.

Farmers can apply 100-200 ml of thiamethoxam + cyantraniliprole per mu with water. Or 300 ml of 40% clothianidin, and 800 ml of 20% clothianidin. Generally, it can achieve more than 95% control effect.

These three pesticides are highly toxic alternative pesticides, which belong to neurotoxin insecticides. Like nicotinoid insecticides, it is the mechanism of action that causes the nerve paralysis of leeks and maggots to stop feeding. In this way, stopping feeding too early can provide a good space for the planted leeks to resume growth.

In order to prevent the occurrence of pesticide damage, it can be used together with Bika foliar fertilizer.

Why do leeks give birth to leek maggots? How can it be prevented? The adult worms of leek maggots are yellow-footed mushroom mosquitoes that tend to yellow and blue light and are sensitive to odors and sweetness.

Leeks have the physiological property of skipping roots. After the new bulb is formed, the old bulb and roots must rot and develop a smell that attracts breeding flies to lay eggs here and produce maggots. Odors from uncleaned shallots after harvest and the use of organic fertilizers that are not adequately decomposed can also attract adults to lay eggs and maggots.

Leek is a kind of vegetable that is planted all over the country, rich in nutrients, and loved by most people, but it is susceptible to various underground pests in the process of growth, among which leek maggot is the most common, the most harmful, and the most difficult to control.

Leek maggots are mainly harmful to young stems and basal bulbs and larvae of leeks. The eggs of the adult worms are concentrated under the surface or in the bulb and leaf sheath of leeks. After the eggs hatch, the larvae first injure the base of the leek leaf sheath and the upper end of the bulb.

As the larvae grow, the mature larvae begin to bite the bulb or underground stems and leaves, causing the aerial parts of the leeks to wilt and die due to lack of nutrients and water, and the larvae pupate in the bulbs or roots after aging.

Resistant varieties can be selected to protect against leek maggots. In general, non-dormant varieties are more resistant to leek maggots than dormant varieties, and vigorous varieties will also have better resistance to leek maggots. In early spring, late autumn and early winter, it should be watered once in the morning and once in the evening, and the amount of watering should be submerged on the back of the ridge for 3 days, which will suffocate the leek maggots.

What is the effect of leek maggots.

1. In Henan, Shanxi, Shaanxi, Gansu, Hebei and other places where the leek-blackhead maggot disease is not serious and the cost of medication per mu is not high, 500ml-1000ml of "vegetable Xiaobai" can be washed with water.

2. In Hebei, Shandong, Northeast and other places where the occurrence of leek blackhead maggots is serious and the cost of medication per mu is high, the dosage per mu can be increased to 1000ml-2000ml mu, and rinsed with water;

3. For dry land, sandy land and leaky land, you can first water with water, and then rinse the medicine, so that the use effect will be better.

The prevention and control of leek maggot should first implement crop rotation stubble, onions, garlic, leek vegetables are similar to the pests and diseases, easy to infect each other, so when leeks are sown or transplanted, if the previous stubble is onions, garlic vegetables, then underground pests, especially leek maggots, will also make the fungus source accumulate, aggravate the occurrence of diseases, will inevitably cause leeks to emerge low seedlings, poor growth potential.

There are 2 reasons for leeks to produce leek maggots, one is to plant leeks with loam, the other is to apply unrotted organic fertilizer, apply fully decomposed organic fertilizer, do not pour manure in the peak period of adult occurrence, fertilization must be done ditch deep application and then cover the soil, remove the roots of leeks, that is, the usual root drying soil, there are 5 6 days to dry the larvae to death.

If the leek plant deteriorates, it is easy to grow maggots, and in this case, insecticides can be used to kill insects.

Proper fertilization. The fertilization of leeks should be mainly organic fertilizer, supplemented by chemical fertilizer, and should be fertilized with nitrogen, phosphorus and potassium balance. Organic fertilizers, especially cake fertilizers, should be fully decomposed before being used to prevent the aggravation of leek maggots; Chemical fertilizer should be applied according to the soil fertility nitrogen, phosphorus and potassium, and trace element fertilizer should be appropriately supplemented to prevent excessive nitrogen fertilizer, so as not to cause plant growth.

Spring pesticide. In early spring, when the soil begins to thaw, the topsoil around the leek roots is removed with a bamboo skewer to expose the leek maggots to the ground and die naturally once they are exposed to low temperatures and dry air. Irrigation to kill insects.

When the larvae of leek maggots occur in spring and autumn, the root system of open-field leeks was continuously watered and flooded for 2 to 3 days. The arched leeks are irrigated in late November and early March of the following year. In the field where the leek maggot occurs severely, irrigation should flood the back of the furrow, which can significantly reduce the damage. Dig the soil and dry the roots.

During the growth period of leeks, the topsoil is removed, and the "leek core" is exposed to dry for 5 7 days, which can kill part of the leek maggots.

You can spray some insecticides, so that you can kill all the small insects, or you can move them to a wider place to keep enough sunlight, and you should also increase the distance between them, not too close, only in this way will not produce small insects.

First of all, when planting, we must choose the soil is more fertile and wide land, and use farmhouse fertilizer, do not use fertilizer bought outside, water the plants more, but also to prevent the occurrence of pests and diseases, if there is a situation of small insects, then we must spray insecticides in time.

First of all, it is necessary to ventilate in time, and it is necessary to prune off these rotten leaves in time, and to ensure the amount of watering and fertilization.

That is, when choosing seeds, it is necessary to choose good quality and strong disease resistance, and then in the process of planting, proper watering, proper fertilization, timely prevention of pests and diseases, timely spraying of pesticides.

You can apply grass and wood ash, many people in the countryside will use farm fertilizer, but there will still be a lot of maggots after using farm fertilizer, so many people will sprinkle grass and wood ash, which can repel insects and control ground maggots.

The application of plant ash, plant ash has a certain bactericidal and antibacterial effect, so it can also inhibit the existence of maggots.

You can eat some pesticides with strong lethality, you can also apply nitrogen fertilizer, you can also apply potassium fertilizer, these fertilizers are relatively high damage to maggots.

Plant ash. Grass ash is the ashes of all kinds of firewood burned in the earthen stove of farmer friends, in the past, every household in the countryside had, it is not only a very nutritious farm fertilizer, but also a "pesticide" commonly used by farmers to repel insects and insects, it is quite effective for the prevention and control of a variety of pests and diseases, and the prevention and control of leek maggots is very practical.

1. Scientific fertilization: do not apply organic fertilizer or cake fertilizer that has not been rotted in the pile, and when applying the rotted fertilizer, it is necessary to open a ditch and apply it deeply and then cover the soil to prevent the adult from laying eggs. 2. Drying roots:

In the peak period of leek maggot, use bamboo skewers or wooden sticks to remove the soil around the leek roots, and dry the roots and soil, and most of the larvae can be sunburned to death after 1 week. 3. Sugar, vinegar and wine trapping: Mix sugar, vinegar, wine and trichlorfon in a certain proportion, and then put it in a box and put it in the planting area, which can trap leek maggots.

First, how to get maggots in leeks

1. Scientific fertilization.

Do not apply organic fertilizer or cake fertilizer to leeks without rotting, and when applying rotting fertilizer, it is necessary to dig a ditch and apply it deeply and then cover the soil to prevent adults from laying eggs. Leek maggots are sensitive to the smell of onions and garlic, like to eat rotten food, and lay eggs on it, so it is necessary to clean up the dead branches and weeds in the vegetable furrow in time to reduce the hatching rate of larvae and the emergence rate of adults.

2. Drying roots:In the peak period of leek maggot, you can use bamboo sticks or wooden sticks to remove the soil around the leek roots, and dry the roots and soil, and most of the larvae can be sunburned to death after about 1 week. Or before covering the soil, you can ditch the grass ash and then cover the soil, after applying the grass ash, you can water as late as possible according to the situation, to ensure that the soil will not be too wet, the prevention and control effect of this method is very good, and the plant ash is also a kind of fertilizer, can promote the growth of leeks.

3. Sugar, vinegar and wine booby-trapping.

This method mainly uses the sensitivity of leeks and maggots to these odors for booby-trapping. Production method: sugar, vinegar, wine and 90% trichlorfon according to the proportion, first dissolve the sugar in water and then add vinegar, wine, water and pesticides, generally every 30 square meters put 1 box, every 5-7 days to replace 1 time of booby trap liquid, every 1 day to add 1 vinegar.

2. How are leeks formed?

1. There are two reasons for leeks to produce leek maggots, one is to plant leeks with loam, and the other is to apply unrotted organic fertilizer. Generally, the peak period of leek maggot damage is from late April to early May, and the peak period is another peak in early October. The larvae overwintering in the protected area can continue to damage leeks, and it is more serious, and the damage of leeks more than 2 years old will be aggravated.

2. The larvae of leek maggots will first feed on the upper end of the young stem at the base of the leek leaf sheath, and mainly harm the young stem of the leek, so that the root rots. The aerial parts of the leeks will become weak, and the leaves will wither and wilt and droop, and finally cause the leeks to wither and die. In the summer, when the temperature is high, the leek maggot will move downwards and begin to eat into the bulb for food, and in severe cases, the bulb will rot and die.

Once the leek is harmed by leek maggots, the leek seedling will wither and cannot send out new shoots, and even if it can send out new shoots, its growth will be very weak.

3. Resistant varieties can be selected to prevent leek maggots, usually the resistance of non-dormant varieties to leek maggots is stronger than that of dormant varieties, and the resistance of strong varieties to leek maggots will be better. In early spring and late autumn and early winter, water should be irrigated once in the morning and evening, and irrigation should be carried out for 3 days in a row, and the amount of irrigation should be used to submerge the back of the ridge, so that the leeks can suffocate and die.