1, sowing: Welsh onion seeds are small, the seed coat is thick, cotyledons are unearthed, the seedlings grow slowly and the seedling stage is long. Seedbed can't have stubble. After the last harvest, deep ploughing and fertilization. Generally, it is made into a high edge with a width of 1.4m (flat ditch). The seedbed should be carefully arranged. Before sowing, the bed surface should be permeable to water and sow new seeds. The seed dosage per mu is 75- 100g. After sowing, cover 2 cm with soil, and then cover with straw or plastic film to speed up the emergence of seedlings.
2. Seedling management: remove the mulch 6-8 days after sowing. At seedling stage, the plants grow less and the transpiration of leaves is less. After emergence to the third leaf stage, fertilizer and water should be controlled to make the root system develop healthily. At the seedling stage, the seedlings should be separated 1-2 times, the over-dense and weak seedlings should be removed, and the seedling spacing should be 7- 10CM, and weeds should be removed.
3. Planting time: Green onions are usually planted from early June to heatstroke (early July). When the onion seedlings grow to a height of 30-40 cm and a transverse diameter of 1- 1.5 cm, they are suitable for transplanting. Before transplanting, the seedbed should be permeable to water 1-2 times, and seedlings should be selected and graded when lifting seedlings. Remove dead leaves, pests and diseases, select robust and non-forked seedlings, and plant them separately according to the size of seedlings. The planting density is generally row spacing 100- 120cm, and the plant spacing is 2.5-3cm. The number of seedlings is 22,000, and the planting depth should be exposed.
4. Field management: After field planting, the physiological functions of aboveground parts and roots are weakened and the growth is slow in summer. At this time, if it is not too dry, it is not suitable for watering more. Drain water after rain to prevent waterlogging and avoid rotten roots, yellow leaves and dead seedlings. We should cultivate, loosen the soil and weed for many times to promote the development of root system.
5. Water and fertilizer management: Autumn is the peak period for the growth of onion leaves and scallions. We must water, topdress and cultivate the soil in time to promote the rapid growth of scallion. Water the onion field frequently to keep the soil moist, and stop watering before harvest 1 week. For the growth and softening of green onions, topdressing and soil culture should be carried out for 3-4 times in August-September. Topdressing is mainly nitrogen fertilizer, and calcium superphosphate and plant ash are applied appropriately, generally once every 15 days. Urea 10- 15kg and calcium superphosphate 15kg were applied per mu. Soil cultivation should be carried out after dew dries in the morning, but the soil is still cool. Carry out soil farming every half month.
6. Pest control: The main diseases of green onions are purple diseases and downy mildew, and the main diseases and insect pests are onion thrips and onion flies, which should be controlled with drugs in time.