The latest course on planting techniques of Welsh Onion

Green onions belong to onion and garlic vegetables. Garlic vegetables include garlic, onions, green onions, shallots, leeks, leeks, buckwheat heads and so on. They all have a special spicy smell, so they are also called spicy vegetables. Spring onions and garlic vegetables are rich in vitamin C, carbohydrates and various minerals, especially sulfur, phosphorus, iron and so on. Eating onions and garlic vegetables can increase appetite and is also an antibacterial substance. People have a penchant for onions and garlic vegetables. The edible part of green onion is mainly pseudostem, which is softened by cultivating soil in the process of cultivation, and its pseudostem becomes onion white, which is also called "white onion".

Welsh onion is a biennial plant, but it is cultivated as a triennial. The traditional cultivation methods are: sowing in the autumn of the first year and overwintering with seedlings; transplanting in the summer of the second year and harvesting green onions in the early winter; if seeds need to be harvested, the grown plants are stored in the open field or facility for overwintering, passing through the vernalization stage at the temperature of 2Mel and 5 ℃, then transplanting to the open field in the third spring, bolting and flowering in the long sunshine, and the Summer Solstice harvesting the seeds.

Green onions can be sowed in autumn or in spring. Green onions for export, usually sown in spring, will be harvested at the end of October of that year and exported after finishing and packaging. The root of Welsh onion is string-like whisker root, which is mainly distributed in the soil layer of 30 cm underground and 15 mi 30 cm horizontally.

Environmental requirements

1. Temperature. Like cool climatic conditions, the optimum temperature for germination is 13 ℃ 20 ℃, the optimum temperature for plant growth is 20 ℃ 25 ℃, the growth is slow below 10 ℃, the growth is weak above 25 mol, the leaves are yellowing and easy to produce diseases, the leaves are semi-dormant at 35 ℃ and 40 mol, and part of the outer leaves wither.

2. Moisture. The drought resistance is very strong, but due to the weak root system, it is necessary to reach 70% of 80% soil moisture, and the growth is favorable when the air humidity is 60-70%.

3. Light. The demand for light is low, so it is suitable for close planting.

4. Soil nutrition. It grows well in loam with good drainage and deep and fertile soil layer. Nitrogen fertilizer is the main fertilizer in the whole growth process, but more phosphorus and potassium fertilizer is needed in the later growth stage.

Cultivate strong seedlings

1. Nursery land selection. Green onion is a vegetable that forbids continuous cropping, and continuous cropping is also avoided in seedling land. The nursery land should choose the high pit land of the previous non-onion and garlic crops. Do not choose barren grass, otherwise the seedling land is overgrown with weeds. Special personnel should be responsible for raising seedlings.

2. After the harvest of the previous crop, turn deep into the sun twice and relax for 20 days. The seedling period of green onion is as long as 50 days, so the seedling field should apply 1000 kilograms of mature fertilizer per mu. The width of the bed is 1.5 meters with a trench, forming a small flat bed with a net width of 1.1 meters. Fine ground preparation. Make a good ditch around.

3, export green onions, the varieties are generally designated by foreign businessmen, mainly: Changbao, Changyue, Mingyan, Jinchang No. 3 and so on. For every 100 grams of seeds, a seedling bed of 35 square meters is required, and the seedlings raised in this way can be transplanted to 1 mu of field. Generally use sowing, sowing should be very uniform. The regular sowing date is early April.

4. After sowing, water should be watered (insecticide is added to the water) to reach 60% of the soil moisture. Do not water the seedlings before emergence. After watering, the fine dry soil is 0.5 cm thick, and the soil can not be watered to prevent soil consolidation. Plastic film can be covered before seedling emergence after sowing, which is beneficial to warming, moisturizing and preventing soil consolidation caused by Rain Water. But to prevent the harm of high temperature.

5. The germination temperature of Welsh onion seeds is the fastest at about 18 ℃. Seedlings can emerge 6 days after sowing. 60% uncover the plastic film in time after emergence, the film is too late, and the seedling is thin and weak. After the plastic film is removed, in order to prevent the erosion of the heavy rain, it is necessary to set up a small ring shed, cover the film on the small ring shed before the rain, and uncover the film after the rain, especially within half a month after the seedling is set up, otherwise a large number of seedlings will fall down due to cataplexy after the heavy rain.

6. when the seedlings stretch, they can be watered once to straighten the cotyledons and root and stabilize the seedlings. In the future, according to the soil moisture in the base area, water will be watered twice. Don't have too much water, lest the seedlings will grow too much.

7. During the whole seedling stage, topdressing 3murs for 4 times, quick-acting organic fertilizer and chemical fertilizer are used alternately, the concentration of chemical fertilizer should be low, no more than 0.5% to promote the seedling growth and lay a good foundation for the cultivation of strong seedlings.

8. During the seedling raising period, if the seedlings show roots, they should cover the dry and fine soil in time, especially after the heavy rain. Weeding and pest control should be carried out in time in the seedling bed.

9, strong seedling standard: seedling height 30 cm, pseudostem diameter 1 cm, leaf color dark green, no diseases and insect pests, nutrient accumulation. The seedling age is about 50 days.

Daejeon preparation

1. Scallions are suitable for growing in loam with good drainage and deep and fertile soil layer. Sandy loam is easy to plant onions, loosen soil and cultivate soil, has good ventilation and is easy to obtain high yield.

2. In order to soften the green onions, the land must be deeply turned over and carefully cultivated. Immediately after the former crops were harvested, the land was ploughed 25cm deep, ploughed and tanned twice. During the last ploughing, 2000 kg of high-quality mature organic fertilizer was applied per mu, and the amount of organic fertilizer should be increased correspondingly in rice ploughs with low soil fertility. Mix well with rotary ploughing. After the trench, the ditch is 30 cm deep, 20 cm wide, and the distance between the two trenches is 1 meter.

3. Ploughing in the ditch with a depth of 20 cm. Base fertilizer is applied at the bottom of the ditch, mainly mature Xie fertilizer, 2000 kg per mu of high-quality Xie fertilizer, so that the soil and fertilizer are mixed, and the soil in the ditch is required to be fine. At this time, the back of the ditch should be more than 30 cm higher than the bottom of the ditch, so that it can be softened later.

4. The ditch system around the field is matched, and a waist ditch is opened at an interval of 20 meters, which is conducive to drainage.

Fine planting

The main results are as follows: 1. the planting time is generally from late May to early June.

2. Before planting, the large and small seedlings were separated, and the diseased seedlings, weak seedlings, over-small seedlings and obviously curved seedlings were removed. The plant spacing was 40 plants per meter, the row spacing was 1 meter, and about 23000 seedlings were planted per mu. Avoid the breaking of green onion seedlings when planting, the planting depth is not to bury the green onion heart, too deep is not suitable for seedling, too shallow affects the length of green onion. When planting, the leaf surface and planting ditch should be arranged in a vertical direction, which is beneficial to close planting and management.

3. Planting tools can use iron cuttings or wood poles with a diameter of about 1.5 centimeters. When planting, make shallow holes first, perpendicular to the ground, then insert the seedlings, and then lift them up slightly to make the roots spread down and keep the onion seedlings straight. If the stem is bent until later harvested, it will become inferior.

4. The planting should be planted on the same side of the onion ditch, which is beneficial to drainage after rain.

5. After planting, the loose soil on both sides of the onion plant was compacted, and then watered thoroughly.

Field management

1. Ploughing and watering

If the weather is not very dry after planting, it is generally not suitable to water again. We should strengthen weeding by ploughing, loosening topsoil, storing water and preserving soil moisture to promote root growth. Pay attention to drainage in case of heavy rain to prevent stagnant water in onion ditch, resulting in high temperature and humidity, poor soil ventilation, rotten roots, yellow leaves and dead seedlings, so waterlogging and drainage preparations should be made before rain.

After the beginning of autumn, as the temperature drops, you can start watering, watering gently, early and late. Later, with the vigorous growth of the plant and gradually increase the number of watering, we must always keep the ground moist, generally to maintain 70% of the soil moisture.

There is generally less Rain Water in October, and the shortage of water in the field is easy to occur. Shallow water irrigation at night can be used to alleviate the drought, but the stagnant water in the field must be eliminated in time. This work should be carried out conscientiously. Watering must be stopped one week before harvest, otherwise the water content is too high and the quality of the outlet will be affected.

2. Soil cultivation and topdressing

At the same time of sufficient supply of fertilizer and water, soil cultivation is an important measure to soften and increase the length of green onions. Generally after living trees, combined with ploughing and weeding to cover a small amount of soil, the compound soil can not bury the green onion heart and can not cause the green onion seedlings to bend. Fill in the planting ditch by the beginning of August. Cultivate the soil after the cool autumn, and then every half a month. The soil was cultivated four times from mid-August to early October. Keep the pseudostem of spring onions straight every time you cultivate the soil, which is an important measure to ensure the quality of white onions for export. Soil cultivation can be done by either a bulldozer or by hand, while machine soil cultivation saves labor and cost. Soil cultivation is carried out when the dew is dry in the morning and the soil is cool. If the soil temperature is too high and the humidity is too high, it is easy to cause rotten stems. When the soil is cultivated for the first and second time, the plant grows slowly and the soil should be shallow; when the soil is cultivated for the third and fourth time, the plant grows rapidly and the soil is thicker. Every time you cultivate the soil, you can't bury the green onion heart, and you can combine with fertilizer when you cultivate the soil. In order to make the onion white more than 30 cm long, the onion stem of more than 35 cm must be buried in the soil. Although the cultivation of soil in some fields has reached four times, the green onion length has not reached, so it must continue. During the typhoon season, soil cultivation should be strengthened to prevent lodging and bending of onion stems. Green onion needs more nitrogen fertilizer for its growth, but more phosphorus and potassium fertilizer for its later growth. Topdressing usually begins after autumn cooling, combined with watering to cultivate the soil. Topdressing is mainly nitrogen fertilizer, and appropriate increase of phosphorus and potassium fertilizer. It was chased twice in August, each time the urea was 8ml / mu and 10kg. After the first ten days of September, the climate is cool, the plants begin to grow vigorously, and the green onion grows rapidly. Attention should be paid to the re-application of topdressing twice from September to the first ten days of October, 10kg of urea per mu and 40kg of imported compound fertilizer. After each topdressing, sufficient water should be poured in time to promote the non-stop growth of green onions.

The total amount of fertilizer per mu of field: medium fertility field, mature organic fertilizer 4000 kg, imported compound fertilizer 80 kg, urea 40 kg.

Pest control

The main diseases of green onion are purple spot, onion rust, soft rot and so on, and the main pests are onion thrips, Liriomyza sinensis, night moth and so on.

1. Purple spot is mainly harmful to leaves and pedicels. At first, it showed a small white spot in the shape of water stains, and then it became light brown round or spindle-shaped slightly sunken spots, and continued to expand in brown or dark purple. The suitable temperature for the disease was 25 ℃. The disease was serious in warm and humid summer, and in old seedlings and fertilizer-deficient fields. Prevention and treatment: crop rotation; at the initial stage of the disease, use chlorothalonil 500x or alum 500x or paracetamol 1500 times spray. 7 Murray once every 10 days, 3 Murray 4 times in a row.

2. Onion rust is mainly harmful to leaves, stems and pedicels. Initially showed orange-yellow or dark brown sore spots, and then scattered orange-yellow or dark brown powder. The optimum temperature for germination of diseased spores was 9 ℃ 18 ℃, and the germination rate decreased significantly when it was higher than 24 May. the disease was serious in years with low air temperature, insufficient fertilizer and poor growth. Prevention and treatment: apply sufficient organic fertilizer and increase phosphorus and potassium fertilizer, and spray 3000 times or 1000 times of mancozeb or chlorothalonil at the initial stage of the disease. Once every 10 days for 3 consecutive times.

3. The soft rot of Welsh onion is caused by bacteria. High temperature and humidity, mechanical injury and insect mouth injury are easy to cause the epidemic of the disease. The symptom of the disease is that the aboveground part of Welsh onion loses, it is easy to pull up, the lower part of the stem is rotten, and there is a stench. Prevention and control: keep the field drainage unobstructed, do not accumulate water after rain; control pests in time to prevent transmission of diseases, and avoid damage to green onions when cultivating soil. The medicament can be controlled by 77% Fengfuan (or 77% can kill) 500x solution and 72% agricultural streptomycin sulfate 4000 times solution.

4. Onion thrips. The adult worm is 1.2 mi 1.4 mm long, which is harmful to the heart leaves and buds of onions. Beneficial onion thrips occur when the relative humidity is below 60% and 25 ℃. Control: 4000 times of Kangfuduo or 2000 times of aphid lice or 20000 times of Ambroxol

5. Liriomyza sinensis. The larvae eat and eat mesophyll in the mesophyll tissue, resulting in reduced yield and quality, and spread the disease at the same time. There are hazards in this area from mid-May to the end of October. Control: Qianke 2500 times or Sukai 1500 times or insecticidal 3000 times or fenvalerate 2000 times liquid spray. The appropriate time for medication is in the morning.

6. Night moth. Spodoptera litura and Spodoptera exigua also damage green onions, eating leaves and drilling into green onions. Generally speaking, the harm is serious in the second half of the year. Spray prevention and control of 1500 times of caramel or 1500 times of rice and 3500 times of hits. The spraying time for the control of night moth is that there is wax powder on the leaf surface of green onions in the evening or dusk. In order to improve the adhesion of the medicine, neutral soap should be added to the liquid. Stop taking medicine 10 days before harvest. Pest control must be carried out by professionals in order to improve the quality and safety of drug use.

Product harvest

It can be harvested from the end of October and can be harvested after the dew dries. Under good cultivation conditions, the total yield per mu is 3000Mu 4000 kg. First turn off the side of the ridge to reveal the green onion and gently pull it out so that the product will not be damaged and shake off the soil. Export products should be properly dried, remove obviously curved plants and green onion plants with a length of less than 30 cm, and tie them into small bundles. Transported to the processing plant without damage.

1. Temperature. The initial germination temperature of Welsh onion seeds is 2 ~ 5 ℃, the optimum temperature for seed germination is 15 ~ 25 ℃, and it can germinate in 2 ~ 3 days. The optimum temperature for leaf growth of Welsh onion is 15: 25 ℃, and the green onion grows vigorously at 10: 20 ℃, which is beneficial to the accumulation of nutrients in leaf sheath. When the growth was more than 25 ℃, the growth was slow, and the quality of the formed leaves and pseudostems were poor. Green onions can tolerate a low temperature of-20 ℃. Shallot and chive like to be cool, the suitable temperature for growth is 13: 20 ℃, the low temperature is about 0 ℃, the quality decreases under high temperature and strong light above 25 ℃, only the growth and tiller are vigorous in spring and autumn.

2. Light. Onions do not have high requirements for light intensity, the light compensation point is 2500 lux and the saturation point is 25000 lux. Spring onions need good light conditions for robust growth, and they are not tolerant to shade and do not like strong light.

3. Moisture. The leaves of spring onions are tubular and waxy on the surface, which can reduce water transpiration and resist drought. However, the absorptive capacity of the root system is poor, so it is necessary to supply appropriate water in each growth and development period. Spring onion seedlings have more requirements for water in the period of vigorous growth, leaf growth, flowering and fruiting, and higher soil moisture should be maintained. Spring onion is not resistant to waterlogging, rainy season should pay attention to timely drainage and waterlogging, to prevent retting roots. Too much water during bolting period is easy to lodge.

4. Soil nutrition. Spring onion has strong adaptability to soil, and the sandy loam with deep soil layer, good drainage and rich organic matter is the best. The soil ph value of 6.9-7.6 is suitable for the growth of onion. Too low and too high can inhibit seed germination and plant growth.