Planting techniques of green onions How to plant green onions?

Onion comes 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 next year and harvesting onions in the early winter; If it is necessary to harvest seeds, the growing plants should be stored in the open field or facilities for wintering, and then go through vernalization at the temperature of 2-5℃, and then transplanted to the open field in the spring of the third year, bolting and flowering under long sunshine, and the seeds should be harvested from summer to Sunday.

Green onions can be sown in autumn or spring. Green onions are usually sown in spring, harvested at the end of that year 10, and then packaged for export. The roots of Welsh onion are string-shaped fibrous roots, which are mainly distributed in the soil layer of 30 cm underground and horizontal 15-30 cm.

environmental requirement

1, temperature. Like cool climate conditions, the optimum temperature for germination is 13-20℃, and the optimum temperature for plant growth is 20-25℃. When the temperature is lower than 10℃, the growth is slow. When the temperature is higher than 25℃, the growth is thin and the leaves turn yellow, which is easy to cause diseases. At 35-40℃, it is in a semi-dormant state, and some outer leaves wither.

2. Moisture. Drought tolerance is very strong, but because the root system is weak, it needs to reach 70-80% soil humidity, and the air humidity is 60-70%, which is beneficial to growth.

3. Lighting. Low light requirement, 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 flute 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 non-garlic crops in the previous crop. Don't choose grass, 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 and bleached twice and left for 20 days. The seedling stage of Chinese onion lasts for 50 days, so Miao Di needs to apply decomposed fertilizer 1 1,000 kg per mu. Ridge width 1.5m, make a small flat ridge with clear width1.1m. Fine soil preparation. Open a ditch system around it.

3. The export varieties of green onions are generally designated by foreign businessmen, mainly including: Changbao, Changyue, Yanming, Jinchang No.3 and so on. Every 1 00g seed needs 35-40m2 seedbed, so the seedlings can be transplanted to1mu field. Generally, sowing is adopted, and the sowing should be very uniform. The normal sowing date is early April.

4. After sowing, water the seeds (add pesticides to the water) to reach 60% soil moisture, and do not water them before emergence. After watering, the fine dry soil is 0.5cm thick. Water is not allowed after watering to prevent soil hardening. Plastic film can be covered after sowing and before emergence, which is beneficial to warming and moisturizing and preventing soil hardening caused by rain. But it is necessary to prevent the harm of high temperature.

5. The germination temperature of Welsh onion seeds is about 65438 08℃, which is the fastest. Seedling can emerge 5-6 days after sowing. 60% of the seedlings are uncovered in time after emergence, which is too late and the seedlings are thin. After removing the plastic film, 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 all the seedlings are planted and before the seedlings are set up, otherwise a large number of seedlings will fall down after the heavy rain.

6. When the seedlings are elongated, water can be poured once to straighten the cotyledons, take root and stabilize the seedlings. In the future, water 1-2 times according to the soil moisture in the base. There should not be too much water to prevent the seedlings from growing 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 0.5%, which will promote the growth of seedlings and lay a good foundation for cultivating strong seedlings.

8. In the process of seedling raising, if the seedlings are bare, they should be covered with dry fine soil in time, especially after heavy rain. The seedbed should be weeded and insect-proof in time.

9. Standard for strong seedlings: the height of seedlings is 30 cm, the diameter of pseudostems is 1 cm, the leaves are dark green, there are no pests and diseases, and there are many accumulated nutrients. The seedling age is about 50 days.

Datian preparation

1, Welsh onion is suitable to grow 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 the green onions are going to be soft, the land must be deeply cultivated. Immediately after harvesting the previous crop, deeply plough the soil for 25-30 cm, and dry it twice after ploughing. For the last ploughing, 2000 kg of high-quality decomposed organic fertilizer should be applied per mu, and the amount of organic fertilizer should be increased correspondingly in paddy fields with low soil fertility. Rotary tillage and mixing. After trenching, the trench depth is 30cm, the trench width is 20cm, and the distance between two trenches is1m.

3. Plow in the ditch with a depth of 20 cm. Base fertilizer should be applied at the bottom of the ditch, mainly decomposed fertilizer, with high-quality fertilizer of 2000 kg per mu, so as to mix soil and fertilizer, and the soil in the ditch should be loose and delicate. At this time, the back of the ditch should be more than 30 cm above the bottom of the ditch, so as to soften it later.

4. The ditches around the site are matched, and a waist ditch is opened every 20 meters to facilitate drainage.

Fine colonization

1, and the planting 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, over-small seedlings and obviously bent seedlings. The plant spacing is 35-40 plants per meter, the row spacing is 1 meter, and about 23,000 plants are planted per mu. When planting, the onion seedlings should be prevented from breaking, and the planting depth should not be buried deep. Too deep is not suitable for raising seedlings, too shallow will affect the length of onions. When planting, the leaves should be arranged vertically with the planting ditch, which is beneficial to close planting and management.

3. The planting tools can be garden iron skewers or garden wooden poles with a diameter of about 1.5 cm. When planting, first make a shallow hole perpendicular to the ground, then insert the seedlings and lift them up slightly, so that the roots will spread downward and keep the onion seedlings straight. If it is bent, the stem will bend 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 conducive to drainage after rain.

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

Tiantuan management

1, intertillage and watering

After planting, if the weather is not very dry, it is generally not suitable for watering. It is necessary to strengthen intertillage weeding, loosen topsoil, store water and conserve moisture, and promote root growth. Pay attention to drainage during heavy rain to prevent water accumulation in onion ditch, resulting in high temperature and humidity, poor soil ventilation, leading to rotten roots, yellow leaves and dead seedlings. So be prepared for flood control and drainage before it rains.

After beginning of autumn, as the temperature drops, you can start watering, light watering, early watering and late watering. In the future, with the vigorous growth of plants, the frequency of watering will gradually increase, and the ground must always be moist, and generally 70-80% of soil moisture should be maintained.

There is little rain in 65438+ 10, and the situation of water shortage in the field is easy to appear. Shallow water irrigation can be used to alleviate the drought at night, but the accumulated water in the field must be removed in time. This work should be carried out seriously. Watering must be stopped one week before harvesting, otherwise the water content is too high, which will affect the export quality.

2. Ridge and topdressing

At the same time, in the case of sufficient fertilizer and water supply, soil cultivation is an important measure to soften and increase the length of green onions. Generally, after living trees, combine intertillage weeding and reapply a small amount of soil. Re-applied soil will not bury the onion heart and cause the onion seedlings to bend. By the beginning of August, the planting ditch will be filled. Cultivate the soil after the autumn is cool, and then cultivate the soil once every half month. From mid-August of 10 to early October of 10, the soil was cultivated for four times. It is an important measure to ensure the quality of exported white onions by keeping the fake stems of onions straight every time the soil is raised. Tillage can be done by tiller or by hand. Using machinery to cultivate soil saves labor and cost. Farming should be done 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 is shallow. During the third and fourth ridging, plants grow rapidly, and the ridging is thicker. Every time you cultivate the soil, you can't bury the onion heart. When you cultivate the soil, you can supplement the fertilizer. To make the length of green onions more than 30 cm, it is necessary to bury the stems of green onions in the soil for more than 35 cm. Although some fields have been plowed for four times, they must be continued before they reach the length of green onion. In the typhoon season, soil cultivation should be strengthened to prevent the onion stems from bending due to lodging. The growth of green onion needs more nitrogen fertilizer, but it needs more phosphorus and potassium fertilizer in the later stage of growth. Topdressing usually begins after the cool autumn, combining watering and soil cultivation. Topdressing is mainly based on nitrogen fertilizer, and phosphorus and potassium fertilizer are appropriately increased. Twice in August, each time urea is 8- 10 kg per mu. After the first ten days of September, the climate was cool, plants began to grow vigorously, and green onions grew rapidly. Pay attention to topdressing twice from September to the first ten days, each time10-12kg of urea and 40kg of imported compound fertilizer. Water in time after each topdressing to promote the growth of green onions, without interruption.

The total amount of fertilizer used per mu of field: the field with medium fertility, 4000 kg of decomposed organic fertilizer, 80 kg of imported compound fertilizer and 40 kg of urea.

control of insect

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

1, purple spots mainly harm leaves and pedicels. At first, it was a white spot like a water stain, and later it became a light brown round or spindle-shaped concave spot, and continued to expand into brown or deep purple. The optimum temperature of the disease is 25-27℃, and it is more severe in warm and humid summer, especially in old seedlings and fertilizer-deficient fields. Control: crop rotation; Spraying with chlorothalonil 500 times or antiviral alum 500 times or chlorpheniramine 1500 times at the initial stage of the disease. 7- 10 day 1 time, 3-4 times in a row.

2. Onion rust mainly harms leaves, stems and pedicels. At first, orange or dark brown sores appeared, and then scattered in orange or dark brown powder. The optimum temperature for germination of diseased spores is 9-65438 08℃. When the temperature is higher than 24℃, the germination rate is obviously reduced. In the year with low temperature, the fertilizer is insufficient and the growth is not good, which is more serious. Prevention and control: apply sufficient organic fertilizer and increase phosphorus and potassium fertilizer; Spraying 3000 times dipyridamole or 1000 times mancozeb or 500 times chlorothalonil at the initial stage of the disease. 10 day 1 time, 2-3 times in a row.

3. Soft rot of scallion is caused by bacteria, and high temperature and humidity, mechanical damage, insect mouth damage, etc. are easy to cause epidemic diseases. The symptoms are that the above-ground part of the scallion falls off, which is easy to pull up, and the lower part of the stem rots and has a foul smell. Prevention and control: keep the site drainage unblocked, and no water will accumulate after rain; Prevent pests from spreading diseases in time and avoid damaging green onions when cultivating soil. 77% fenghuan (or 77% chlorhexidine) 500 times solution and 72% agricultural streptomycin sulfate 4000 times solution can be used for control.

4. Onion thrips. The adult is 1.2- 1.4 mm long, which is harmful to the heart leaves and buds of onion. When the temperature is lower than 25℃ and the relative humidity is lower than 60%, it is beneficial to the occurrence of onion thrips. ...

5. leaflets. Larvae feed on mesophyll tissue, which leads to the decrease of yield and quality and the spread of diseases. It is harmful for this area to end at 10 in mid-May. Prevention and control: 2500 times or 1500 times of quick-opening or 3000 times of insecticide or 2000 times of pyrethrin. It is wise to take medicine in the morning.

6. Noctuidae Spodoptera litura and Spodoptera exigua also harm green onions, eat leaves and eat them dry. Generally, it is more harmful in the second half of the year. Spray with carbendazim 1500 times or amphetamines 1500 times and 3500 times. The spraying time of Noctuidae is preferably in the evening or dusk. There is wax powder on the leaves of green onions. In order to improve the adhesion of drugs, neutral soap should be added to the liquid medicine. Stop the drug before harvest 10 day. Pest control must be organized by professionals to improve the quality and safe use of drugs.

Product harvest

It can be harvested after 10, and harvested after the dew is dry. Under good cultivation conditions, the yield per mu can reach 3000-4000 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 or shake off the soil. Export products should be properly aired, and obviously bent plants and plants with onion length less than 30 cm should be removed and bundled into small bundles. Transport to the 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 onion leaves is 15 ~ 25℃. When 10 ~ 20℃, Welsh onion grows vigorously, which is beneficial to the accumulation of nutrients in leaf sheath. Over 25℃, the growth is slow, and the quality of leaves and pseudostems is poor. Onions can tolerate a low temperature of MINUS 20 degrees. Divided onions and leeks like to be cool, the suitable growth temperature is 13 ~ 20℃, the low temperature is about 0℃, and the quality decreases under the high temperature and strong light above 25℃, and the tillers grow vigorously only in spring and autumn.

2. Lighting. Onions don't need high light intensity. The light compensation point is 2500 lux and the saturation point is 25000 lux. The vigorous growth of onion needs good lighting conditions, and it is not tolerant of shade and does not like strong light.

3. Moisture. Onion leaves are tubular with waxy surface, which can reduce water transpiration and resist drought. However, the absorption capacity of root system is poor, so it is necessary to supply appropriate amount of water in each growth and development period. Onion seedling vigorous growth period, leaf vigorous growth period and flowering and fruiting period require more water, so high soil moisture should be maintained. Onions are 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. The soil ph value is 6.9 ~ 7.6, which is suitable for onion growth. Too low or too high will inhibit seed germination and plant growth.