Green onions have been cultivated in my country for more than 2,000 years. The main edible parts are the fat pseudobulbs and young leaves, which can be eaten raw or cooked. It is one of the essential condiments for the family. So in the process of planting green onions, how can we grow thick and long white onions? Next, I will talk about the cultivation technology of green onions based on our experience in growing green onions in Gansu.

1. Green onion seedlings

1. Selection of seedling land

For green onion seedlings, choose sandy loam soil with fertile soil, flat terrain, and convenient watering and drainage. As appropriate.

2. Land preparation and fertilization

In combination with land preparation, apply 2,500 kilograms of decomposed high-quality farmyard manure or 200 to 300 kilograms of commercial organic fertilizer and 20 to 30 kilograms of potassium sulfate compound fertilizer per mu.

In order to prevent and control the harm of soil-borne diseases, 500 grams of 40% phoxim emulsifiable concentrate can be mixed with fine sandy soil per acre to form poisonous soil. Rice is used as a flat border, and the direction of the border surface should be conducive to irrigation and drainage.

3. Sowing

The sowing period should be sown at the appropriate time according to the actual local climate conditions. We in Gansu are divided into spring sowing and autumn sowing. Early spring sowing is sown after the soil thaws; autumn sowing is Generally, it is carried out in early September, after the beginning of autumn, when the seedlings can reach 2 to 3 true leaves and the plant height is about 10 cm before the soil freezes.

After sun-drying for 1 to 2 days before sowing, spread the seeds evenly on the previously prepared border. The seed amount is generally 3 to 4 kilograms per acre. After sowing, rake lightly and compact.

4. Management of green onions in the seedling stage

Management in the seedling stage Spring sowing and autumn sowing are in different seasons, so there are differences in management. Management of spring sown seedlings: Spring sown seedlings enter a vigorous growth period after emergence, so the supply of fertilizer, water and fertilizer should be strengthened, 5 to 8 kilograms of urea should be applied in two batches with a watering interval of 15 to 20 days, and cultivating and weeding should be carried out in a timely manner. Management of autumn sown seedlings: During the seedling emergence period of autumn sown seedlings, the soil must be moist to ensure complete emergence, and frozen water should be poured before the soil freezes; after turning green in spring, fertilize twice with an interval of 15 to 20 days, and apply 5 to 8 kilograms of urea per mu. .

2. Green onion planting management

1. Land preparation and fertilization

Choose soil rich in organic matter, loose soil, good drainage, and the best choice for the previous crop is non-onion and garlic. For such fields, apply 2,500 to 3,500 kilograms of decomposed high-quality farmyard manure or 240 to 400 kilograms of commercial organic fertilizer, 30 to 40 kilograms of potassium sulfate ternary compound fertilizer, 40 kilograms of superphosphate, 10 kilograms of diammonium phosphate, or ammonium nitrate per mu. 20~30kg, plow 25cm deep and then harrow and level it.

2. Ditching and ridging

First use a hoe of about 20 cm to dig a trench to a depth of 15 to 20 cm, then use a hoe of 10 cm to continue trenching to a depth of 30 cm. The spacing should be maintained at 40 to 60 centimeters, and the excavated soil should be compacted on both sides for soil cultivation during the growth period. Mix 500 grams of 40% phoxim EC per acre with fine sandy soil and spread it after trenching to prevent underground pests.

3. Planting

When planting, first grade the seedlings according to the size of the rhizomes, and then transplant the graded seedlings according to their sizes to facilitate later field management. When transplanting seedlings, the distance between plants should be 3 to 5 centimeters and the transplanting amount per mu should be about 27,000 plants. When planting seedlings, keep the onion roots evenly down, shovel a small amount of fine soil to compact the onion roots to a depth that does not bury the inner leaves.

3. Management after transplantation

Generally, after onion seedlings are transplanted, new roots will sprout and new leaves will begin to grow in 3 to 7 days. This period is the seedling slowing period. The best management work is to promote the growth of the root system. After the green onions are slowed down, they immediately enter the vigorous growth period. The vigorous growth period is a critical period for the plants to increase in height, the pseudostems to gain fat, and the green onions to become white. Therefore, the management of fertilizer and water should be strengthened.

1. Topdressing

When entering the vigorous growth period, the first topdressing should be carried out in combination with soil cultivation. Spread 10 to 15 kilograms of urea per mu in the onion ditch, then cultivate the soil and water it; when it is about to enter the "summer heat" season, carry out the second top dressing, apply 10 to 15 kilograms of urea per mu and 15 kilograms of potassium sulfate ternary compound fertilizer. ~20 kilograms, apply the same fertilizer, then cultivate the soil and water it; during the "White Dew" and "Autumn Equinox" seasons, perform top dressing, soil cultivation, and watering respectively. The method is the same as above. After each watering, perform cultivating and weeding, and add 1 to 2 centimeters of soil into the ditch to prevent soil compaction and sun cracking.

2. Soil cultivation

Soil cultivation is the process of mounding the soil on the furrow platform around the onion roots. It can increase the height of the green onion plant, the length and the middle volume of the green onion. When cultivating the soil, try to do it on a sunny day without dew, so as not to bury the core leaves.

When cultivating the soil, the first and second soil cultivation should be done shallowly because the transplanted seedlings grow slowly; the third to fourth soil cultivation should be done when the new roots have taken root and are growing. Rapidly, so the soil should be cultivated deeply when cultivating. Generally speaking, according to the growth conditions of green onions, the number of soil cultivation should be no less than 4 times before harvesting.

3. Watering

When watering green onions, follow the principles of frequent watering, morning and evening watering, and combine soil cultivation and top dressing. When the solar term reaches "Frost Descent", Gradually reduce the frequency of watering and stop watering 15 days before harvesting to better extend the storage time of green onions.

4. Prevention and control of pests and diseases of green onions

The main field diseases of green onions include downy mildew, purple spot, rust, white spot disease, etc. The main pests include onion leafminer and onion thistle. Horses, mole crickets, grubs, etc.

1. Agricultural prevention and control

The first is to promptly clean up the diseased remains in the field so that the pathogens have no host to survive the winter; the second is to implement crop rotation to reduce obstacles to continuous cropping; the third is to scientifically and reasonably close planting ; The fourth is to strengthen field management and remove weeds in time; the fifth is to apply more organic fertilizers and increase the application of phosphorus and potassium fertilizers to improve the stress resistance of plants.

2. Pesticide control

Chemical control follows the principle of “prevention first, comprehensive prevention”. Downy mildew: In the early stage of the disease, use chlorothalonil, mancozeb, and mancozeb metalaxyl to prevent and control the disease. Spray once every 7 to 10 days and spray 2 to 3 times alternately. Purple spot disease: Before sowing, soak the seeds in warm water at 45°C for 1.5 hours for disinfection; in the early stage of the disease, use Bordeaux mixture or mancozeb, dense first and thin second, alternately spray two or three times. Rust: In the early stage of the disease, use mancozeb, mancozeb plus mancozeb, spray once every 10 days, and spray 1 to 3 times continuously. Onion-spotted leafminer: The larvae feed on the mesophyll of the leaf, and zigzag and snake-shaped tunnels can be seen on the leaf surface. In severe cases, a single leaf can be eaten by more than a dozen larvae, resulting in reduced photosynthesis and reduced yield. Control methods: Use abamectin, dimethoate emulsion or trichlorfon, spray once every 5 to 7 days, and spray 2 to 3 times alternately. Stop medication 15 days before harvest.

In short, if you want to obtain white onions with thick and long stalks, you must be meticulous in field management from sowing to planting and pest control. This is a prerequisite for high yields of green onions. .