Five key steps for raising onion seedlings
Onions have the characteristics of low input, high yield, simple management and high returns, making them an ideal vegetable variety for vegetable growers to carry out commercial production and increase income. Early September is the best time for raising onion seedlings. The relevant key technical points for raising seedlings are introduced below. Seed selection: In production, purple-skinned varieties such as Ziyu No. 1, Ziyu...
Onions have the characteristics of low input, high yield, simple management and high returns, making them an ideal vegetable variety for vegetable growers to carry out commercial production and increase income. Early September is the best time for raising onion seedlings. The relevant key technical points for raising seedlings are introduced below.
Seed selection
In production, purple-skinned varieties such as Ziyu No. 1, Ziyu No. 2, Zixing and Shuanghuanhong can be selected. These varieties have the characteristics of strong pungency, high yield, excellent quality and suitability for export. These varieties generally yield about 5000 kg per mu, and high-yield plots can reach 7500 kg per mu.
Seedbed
The seedbed should be selected on plots with loose, fertile soil and strong water retention that have not grown scallions or garlic vegetables within 3 years. To raise seedlings for each mu of field, about 35 sq m of seedbed area is needed, with a seeding rate of 0.5 kg. Before sowing, apply sufficient decomposed farmyard manure, plus 20-30 kg of nitrogen, phosphorus and potassium compound fertilizer, then plow, finely prepare the soil, make beds 1.5-2 m wide, water thoroughly, and wait to sow.
Sowing
The timing of sowing directly affects the size of the seedlings, and thus ultimately affects onion yield. Sowing early prolongs the seedling growth period, causing the nutritional area to be too large, and the seedlings are prone to bolting; sowing late makes the seedlings weak and small with low cold resistance, and they are prone to dying during overwintering. Therefore, to achieve high yield, it is necessary to grasp the optimal sowing period. According to the experience of local vegetable growers, the most suitable sowing period is 3 days around White Dew (early September). Use dry seed broadcasting, and after sowing cover with fine soil, with the seeds just covered. After covering with soil, 100 ml of 33% pendimethalin can be sprayed per mu of seedbed to prevent and remove weeds in the seedbed.
Management
After sowing, cover the bed surface with a layer of wheat straw, which helps retain moisture, prevent high temperatures and prevent rain. Keep the soil moist until emergence. When about 60% of the seedlings have emerged in the seedbed, the covering can be removed. Sprinkle water promptly according to weather conditions to prevent the seedbed from hardening, and apply a small amount of urea along with watering. Through the regulation of fertilizer and water, cultivate strong seedlings of the appropriate age. It is necessary both to prevent the seedlings from growing too large and causing early bolting, and to avoid the seedlings growing thin and weak and affecting overwintering. Generally, when onion seedlings grow to 4 true leaves, a plant height of 20-25 cm, and a leaf sheath diameter of 6-7 mm, they can be transplanted.
Transplanting
When transplanting, the onion seedlings should be transplanted separately according to size so that they grow uniformly, and large seedlings with a leaf sheath diameter over 8 mm, as well as weak and small seedlings and diseased seedlings below 3 mm, should be removed. Transplanting is generally completed from late October to early November, and should be carried out when the daily average temperature is 4°C-5°C. Because onions need about 30 days from transplanting to resuming growth, their root systems must be encouraged to develop and grow well before severe cold arrives, to prevent soil freezing and lifting the roots and causing seedling death. The transplanting density requires a row spacing of 20 cm and a plant spacing of 15 cm, and the transplanting depth should preferably not bury the five-fork joint. After transplanting, water to promote the survival of onion seedlings. Never flood-irrigate, which causes soil hardening and is not conducive to the rapid resumption of growth of onions.