In recent years, with the continuous increase in the price of spring onions, onion farmers have become more confident in planting spring onions. Autumn is the peak season for spring onion seedlings because self-propagation costs less and growers have the freedom to choose varieties. Therefore, many large-scale onion growers now prefer to raise their own seedlings. Let's talk about autumn seeding techniques for growing spring onions.
Autumn Seeding Techniques for Growing Spring Onions
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Seedling Time: Autumn seeding for spring onions generally starts in early September. Sowing too early may result in premature bolting, while sowing too late may risk frost damage. Before winter, seedlings typically have 2-3 leaves, with a plant height of around 10 centimeters and a basal stem diameter of less than 0.5 centimeters.
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Seed Treatment: Soak the seeds in clean water and stir for 10 minutes to remove impurities. Then immerse the seeds in water at around 65°C for 20-30 minutes, stirring continuously. Pre-soaking the seeds can expedite germination by 1-2 days.
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Sowing: Use fresh seeds from the current year, with a seeding rate of 3-4 kilograms per acre, suitable for planting 6-8 acres. If using seeds from the previous year, double the seeding rate, and seeds older than two years should not be used. Broadcasting and row sowing are common methods. Ensure the seedbed is well-watered, sow evenly, and cover with about 1 centimeter of fine soil. Row sowing involves shallow furrows spaced at 12 centimeters apart, with seeds sown inside and the furrows gently covered.
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Management: Keep the seedbed moist before and after emergence to ensure normal seedling emergence. From emergence to winter, water and fertilize according to soil fertility and seedling growth. Water once before the first frost. When the average daily temperature rises to 13.5°C during the second year, start watering and fertilizing, followed by thinning, intertillage, water control, and seedling squatting for 12-15 days. After squatting, the seedlings enter a vigorous growth phase and should be watered and fertilized 2-3 times, with urea applied at a rate of 20-30 kilograms per acre.
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Thinning: Thinning is usually done twice. The first thinning occurs during the slow growth period after the second year's watering, with a spacing of 2-3 centimeters between seedlings. The second thinning is when the seedlings reach a height of about 20 centimeters, with an ideal density of around 140,000 plants per acre. For row-sown fields, adjust spacing accordingly to maintain sufficient individual plant nutrition area.
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Healthy Seedling Development: Healthy seedlings should be around 50 centimeters tall with white bulbs of approximately 25 centimeters, vibrant green leaves numbering 5-6 per plant, and individual plant weight of over 40 grams.
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Pest and Disease Control: Pest infestations during the seedling stage are usually mild but require prompt treatment upon detection.
These are the techniques for autumn seeding of spring onions. Seedling management is generally simpler than field management after transplantation. With proper care, your onion seedlings will thrive.
