Planting techniques of green onions How to plant green onions?

Onion is from biennial plants, but it is cultivated as a triennial. Traditional cultivation method, sowing in autumn in the first year, overwintering with seedlings; Transplanting in the summer of the following year, and harvesting scallion in the early winter; If seeds need to be harvested, the growing plants will be stored in the open field or in facilities for overwintering, pass through vernalization stage at the temperature of 2-5℃, and then transplanted to the open field in the spring of the third year, bolting and flowering in the long sunshine, and harvesting seeds in the summer solstice.

green onions can be sown in autumn or spring. The export of green onions, usually sown in spring, was harvested at the end of October of that year, and then packaged and exported. The roots of green onions are string-shaped fibrous roots, which are mainly distributed in the soil layer 3 cm underground and 15-3 cm horizontally.

environmental requirements

1. temperature. I like cool climate conditions. The optimum temperature for germination is 13-2℃, and the optimum temperature for plant growth is 2-25℃. When it is below 1℃, it grows slowly. When it is above 25℃, it grows thin and leaves are yellow, which is easy to cause diseases. At 35-4℃, it is in a semi-dormant state and some outer leaves wither.

2, moisture. Drought tolerance is very strong, but due to weak roots, it needs to reach 7-8% soil humidity, and it is beneficial to grow when air humidity is 6-7%.

3. Lighting. 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. The whole growth process is dominated by nitrogen fertilizer, but more phosphorus and potassium fertilizer are needed in the later growth stage.

cultivate strong seedlings

1. Miao Di selection. Onion is a vegetable that should not be continuously cropped, nor should it be continuously cropped in the nursery. Miao Di should choose high pits for non-onion and garlic crops in the previous crop. Don't choose grassland, or Miao Di will be overgrown with weeds. Someone should be responsible for raising seedlings.

2. After the previous crop is harvested, it is deeply turned over and bleached twice, and it is laid for 2 days. The seedling period of scallion is as long as 5 days, so Miao Di needs to apply 1 kilograms of decomposed fertilizer per mu. The border is 1.5 meters wide and connected with the ditch, and a small flat border with a net width of 1.1 meters is made. Fine soil preparation. Open a ditch system around.

3. The export varieties of green onions are generally designated by foreign businessmen, mainly including Changbao, Changyue, Mingyan and Jinchang No.3.. Every 1 grams of seeds need 35-4 square meters of seedbed, so the seedlings can be transplanted to 1 mu of field. Generally, sowing is adopted, and the sowing should be very uniform. The regular sowing date is early April.

4. water the seeds after sowing (adding pesticides to the water) to reach 6% soil moisture, and do not water them before emergence. After watering, fine dry soil is .5 cm thick. After watering, it is not allowed to water to prevent soil hardening. Plastic film can be covered after sowing and before emergence, which is beneficial to warming, moisturizing and preventing soil hardening caused by rain. But to prevent the harm of high temperature.

5. The germination temperature of Welsh onion seeds is about 18℃, which is the fastest. Seedling can emerge 5-6 days after sowing. 6% of the seedlings were uncovered in time after emergence, which was too late and the seedlings were thin and weak. After the plastic film is removed, in order to prevent the heavy rain from washing away, a small ring shed should be set up, and the film should be covered on the small ring shed before the rain, and the film should be removed after the rain, especially within half a month after the seedlings are fully planted and before the seedlings are set up, otherwise a large number of seedlings will fall down after heavy rain.

6. When the seedlings stretch out, water can be poured once to straighten the cotyledons, take root and stabilize the seedlings. Later, according to the situation of soil moisture in the base area, water it 1-2 times. Water should not be too much, lest the seedlings grow in vain.

7. Topdressing for 3-4 times during the whole seedling stage, using quick-acting organic fertilizer and chemical fertilizer alternately, and the concentration of chemical fertilizer should be low, not exceeding .5%, which will promote the growth of seedlings and lay a good foundation for cultivating strong seedlings.

8. During seedling raising, if seedlings are exposed, dry fine soil should be covered in time, especially after heavy rain. Weeding and pest control should be done in the seedbed in time.

9. standard for strong seedlings: the height of seedlings is 3cm, the thickness of pseudostems is 1cm, the leaves are dark green, there are no pests and diseases, and there are many nutrients accumulated. The seedling age is about 5 days.

field preparation

1. Welsh onion is suitable for growing in loam with good drainage and deep and fertile soil layer. Sandy loam is easy to insert onions, loosen soil and cultivate soil, with good aeration and easy to obtain high yield.

2. Because of the softening of green onions, the land must be deeply ploughed and carefully cultivated. Immediately after the previous crops are harvested, the soil is deeply ploughed by 25-3 cm, and the ploughing is sun-dried twice. In the last ploughing, 2, kg of high-quality decomposed organic fertilizer is applied per mu, and the amount of organic fertilizer should be increased correspondingly in the paddy field with low soil fertility. Rotary tillage and mixing. After trenching, the depth of the trench is 3cm, the width of the trench is 2cm, and the distance between the two trenches is 1m.

3. Plow in the ditch with a depth of 2cm. Base fertilizer should be applied at the bottom of the ditch, mainly decomposed fertilizer, with high quality fertilizer of 2 kg per mu, so that the soil and fertilizer can be mixed, and the soil in the ditch should be loose and fine. At this time, the back of the ditch should be more than 3 cm above the bottom of the ditch, so as to soften it later.

4. The ditches around the field are matched, and a waist ditch is opened at an interval of 2 meters, which is beneficial to drainage.

precise colonization

1. The colonization time is generally from late May to early June.

2. Before planting, separate the big and small seedlings, and eliminate the diseased seedlings, weak seedlings, excessively small seedlings and obviously bent seedlings. The plant spacing is 35-4 plants per meter, the row spacing is 1 meter, and about 23, plants are planted per mu. When planting, the onion seedlings should be avoided from breaking, and the depth of planting should not be buried. Too deep is not suitable for seedlings, and too shallow will affect the length of onion. When planting, the leaves should be arranged vertically with the planting ditch, which is beneficial to close planting and management.

3. The planting tool can be a round iron skewer or a round wooden pole with a diameter of about 1.5cm. When planting, first make a shallow hole, which is vertical to the ground, then insert the seedlings, and then lift them up slightly, so as to make the roots spread down and keep the onion seedlings straight. If it is bent, the stem will be bent until it is harvested later, which is a defective product.

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

5. After planting, compact the loose soil on both sides of the onion plant, and then water it.

field management

1. intertillage and watering

After planting, if the weather is not very dry, it is generally not suitable to water again. We should strengthen intertillage weeding, loosen topsoil and store water to conserve moisture to promote root growth. Pay attention to drainage in case of heavy rain to prevent water accumulation in onion ditch, resulting in high temperature and humidity and poor soil ventilation, leading to rotten roots, yellow leaves and dead seedlings. Therefore, preparations should be made for flood prevention and drainage before rain.

After beginning of autumn, as the temperature drops, you can start watering, watering lightly, and watering in the morning and evening. In the future, with the vigorous growth of plants, the watering frequency will be gradually increased, and the ground must be kept moist frequently, generally 7-8% soil moisture should be maintained.

There is little rain in October, and water shortage in fields is easy to occur. Shallow water irrigation can be used at night to alleviate the drought, but water accumulation in fields must be eliminated in time. This work should be carried out seriously. Watering must be stopped one week before harvest, otherwise the water content is too high and the export quality will be affected.

2. Soil cultivation and topdressing

While fertilizer and water are sufficient, soil cultivation is an important measure to soften and increase the length of scallion. Generally, after living the tree, a small amount of soil should be re-applied in combination with intertillage weeding. The re-applied soil can not bury the onion heart and cause the onion seedlings to bend. By the beginning of August, the planting ditch will be filled up. After the autumn is cool, cultivate the soil, and then cultivate the soil every half month. From mid-August to early October, the soil was cultivated four times. It is an important measure to ensure the quality of exported white onions to keep the fake stems of onions straight every time the soil is cultivated. Soil-raising can be done by using a soil-raising machine or by hand. Soil-raising by using a machine saves labor and costs. Tillage shall be carried out in the morning when the dew is dry 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. During the first and second ridging, the plants grow slowly and the ridging should be shallow. During the third and fourth times of soil cultivation, plants grow rapidly, and the soil cultivation should be thicker. Every time you cultivate the soil, you can't bury the onion heart. When you cultivate the soil, you can combine with supplementary fertilizer. To make the length of scallion more than 3 cm, it is necessary to bury the scallion stems more than 35 cm in the soil. Although some fields have been cultivated for four times, they must be continued before the length of scallion is reached. In typhoon season, it is necessary to strengthen soil cultivation to prevent the onion stems from bending due to lodging. The growth of Welsh onion requires more nitrogen fertilizer, but it needs more phosphorus and potassium fertilizer in the later stage of growth. Topdressing usually begins after cool autumn, combined with watering and soil cultivation. Topdressing is mainly based on nitrogen fertilizer, and phosphorus and potassium fertilizer are appropriately increased. Chasing twice in August, with 8-1kg urea per mu each time. After the first ten days of September, the climate is cool, the plants begin to grow vigorously, and the scallion grows rapidly. Pay attention to topdressing twice from September to the first ten days of October, with 1-12 kilograms of urea per mu and 4 kilograms of imported compound fertilizer each time. After each topdressing, water should be poured in time to promote the growth of green onions without stopping.

the total amount of fertilizer used per mu of field: fields with moderate fertility, 4 kg of decomposed organic fertilizer, 8 kg of imported compound fertilizer and 4 kg of urea.

pest control

The main diseases of Chinese onion are purple spot, onion rust, soft rot, etc. The main pests are onion thrips, liriomyza sativae, Noctuidae and so on.

1. Purple spot mainly damages leaves and pedicels. At first, it is white spots like water stains, and then it becomes light brown round or spindle-shaped slightly concave spots, and it continues to expand into brown or dark purple. The optimum temperature of the disease is 25-27℃, and the disease is serious in warm and humid summer, and the disease is serious in old seedlings and fertilizer-deficient fields. Control: crop rotation; At the beginning of the disease, spray with chlorothalonil 5 times or antivirus alum 5 times or chlorphenamine 15 times. Once every 7-1 days for 3-4 times in a row.

2. Onion rust mainly damages leaves, stems and pedicels. Orange or dark brown sores appear at first, and then orange or dark brown powder is scattered. The optimum temperature for germination of diseased spores is 9-18℃. When the temperature is higher than 24℃, the germination rate is obviously reduced. The years with low temperature, insufficient fertilizer and poor growth are more serious. Prevention and control: apply sufficient organic fertilizer and increase phosphorus and potassium fertilizer; At the beginning of the disease, 3 times of Diplodipine, 1 times of Mancozeb or 5 times of Chlorothalonil were sprayed. Once every 1 days, 2-3 times in a row.

3. Soft rot of scallion is caused by bacteria, and high temperature and high humidity, mechanical injury and insect mouth injury are easy to cause epidemic diseases. The symptoms of the disease are that the aboveground part of the scallion falls, which is easy to pull up, the lower part of the stem rots and has a foul smell. Prevention and control: keep the field drainage unblocked, and do not accumulate water after rain; Prevent pests from spreading diseases in time, and avoid damaging green onions when cultivating soil. 5-fold solution of 77% Fenghuan (or 77% kocide) and 4-fold solution of 72% agricultural streptomycin sulfate can be used for control.

4. Onion thrips. Adults are 1.2-1.4 mm long, which is harmful to the heart leaves and buds of onion. When the temperature is below 25℃ and the relative humidity is below 6%, it is beneficial to the occurrence of onion thrips ... Control: 4, times of Kangfuduo or 2, times of Aphidine or 2, times of Imiprole

5. Larvae eat in mesophyll tissue, eating mesophyll, resulting in yield reduction and quality decline, and at the same time spreading diseases. This area is harmful from mid-May to the end of October. Prevention and control: 25 times of chlorfenapyr or 15 times of chlorfenapyr or 3 times of insecticidal or 2 times of pyrethrin. It is advisable to take medicine in the morning.

6. Noctuidae. Spodoptera litura and Spodoptera exigua also harm green onions, eating leaves and boring them. Generally, it is more harmful in the second half of the year. Prevention and treatment by spraying 15-fold solution of carbaryl or 15-fold solution of rice full and 35-fold solution of amphetamine. The spraying time of controlling Noctuidae is good in the evening or dusk. There is wax powder on the leaves of Chinese onion. In order to improve the adhesive force of the medicine, neutral soap should be added to the liquid medicine. Stop taking medicine 1 days before harvesting. Pest control must be organized by professionals to improve the quality and safe use of drugs.

product harvesting

it can be harvested at the end of October, and harvested after dew drying. Under good cultivation conditions, the total yield per mu is 3-4 kg. First, split one side of the ridge platform to expose the scallion, and then gently pull it out, so that the product will not be damaged and shake off the soil. Export products should be properly aired, and obviously bent plants and plants with scallion less than 3 cm long should be removed and bundled into small bundles. Transport to that processing plant without damage.

1. temperature. The initial germination temperature of Welsh onion seeds is 2 ~ 5℃, and the optimum germination temperature is 15 ~ 25℃, which can germinate in 2 ~ 3 days. The optimum temperature for the growth of green onion leaves is 15 ~ 25℃, and the onion white grows vigorously at 1 ~ 2℃, which is beneficial to the accumulation of nutrients in leaf sheaths. If it exceeds 25℃, the growth will be slow, and the quality of leaves and pseudostems will be poor. Onion can endure the low temperature of-2℃. Scallion and chive are cool-loving, and their growth temperature is 13 ~ 2℃, and they can withstand low temperature of about ℃. When the temperature is above 25℃ and under strong light, their quality declines, and they only grow and tiller vigorously in spring and autumn.

2. Lighting. Onion does not require high light intensity. The light compensation point is 25 lux and the saturation point is 25 lux. The strong growth of onion needs good lighting conditions, and it is not tolerant of shade and does not like strong light.

3, moisture. The leaves of onion are tubular and the surface is waxy, which can reduce water transpiration and resist drought. However, the absorption capacity of root system is poor, so it is necessary to supply appropriate water in each growth and development period. There are many requirements for water in the vigorous growth period of onion seedlings, vigorous growth period of leaves and flowering and fruiting period, so high soil moisture should be maintained. Onion is not tolerant to waterlogging, so attention should be paid to timely drainage and waterlogging prevention in rainy season to prevent root retting. Too much water at bolting stage is easy to lodging.

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