How to plant onion seedlings

Planting time: the seeds can be sown in mid-September, no later than mid-October at the latest, and then planted in the first and middle of November. Select varieties: choose high-quality varieties such as Yuyuan Hongxing and Nine tons Red. Seedling raising: wet the soil after the whole bed, then sow the seeds and fine sandy soil at the ratio of 1:10, cover the soil with 1cm or so, and wait for the seedlings to grow to about 4cm. Planting: turn the soil deeply for fertilization, then rake the ground and ridge for planting, which needs to be covered with film in advance.

First, planting time

Onions are sown in mid-September, not earlier than September 1 at the earliest, and no later than October 15 at the latest. Planting onions can be planted in the first and middle of November, and no later than November 25 at the latest.

2. Selection of varieties

1. Yuyuan Hongxing: this variety is cultivated by the Institute of Horticulture of Henan Academy of Agricultural Sciences, the outer skin is red, and the weight of single ball is about 0.6jin. It has the advantages of high yield, disease resistance and strong adaptability, with an average yield of 11000 jin per mu.

2. Nine tons of red: this variety is introduced from abroad, the outer skin is red, it is more than 50% higher than the common variety, the weight of single ball is about 0.8 jin, and it is mainly resistant to pink root rot.

3. Raising seedlings

1. Seedling raising time: Yuyuan Hongxing can choose to raise seedlings in 1-2 days before and after White Dew, and nine tons of red can choose to raise seedlings in the middle of September.

2. Seedling raising method: after finishing the border, the soil should be soaked thoroughly, and after the water permeated, the seeds and fine sandy soil should be mixed and sowed evenly according to the proportion of 1:10. After seed allocation, the fine soil should be covered with 1cm or so, and phoxim granules should be applied, using 4 jin of seeds per mu of seedling bed.

3. Seedling bed management: when the seedlings grew to 4-5cm, the seedlings were interspersed for 2-3 times, and the seedling spacing was kept at 3-4cm.

IV. Colonization

Before planting, the soil should be ploughed and fertilized. Generally, 8000-10000 jin of rotten organic fertilizer, 100jin of diammonium phosphate and 100jin of calcium superphosphate should be applied per mu. After fertilization, 25-30cm of soil should be deeply ploughed, combined with 2 jin of phoxim granules per mu, and ridges should be planted after raking the ground. The ridge bottom width is 90cm, top width is 70-72cm, height is 5-7cm, each ridge is planted in 5 rows, and the plastic film is covered in advance.

5. Select and fix seedlings

The seedlings with 20cm height, 0.6-0.9cm stem diameter, 3-4 leaves and 5-6 g weight were selected, the row spacing was 17-22cm, the plant spacing was 15-17cm, and 22000-24000 plants per mu were planted. The suitable planting depth was buried bulb 1cm, watering in time after planting, and sealing with soil after water infiltration, which was beneficial to heat preservation and soil moisture conservation.

VI. Management after planting

In winter, measures such as soil moisture conservation and plastic film protection should be done well. After turning green, it should be watered 4-5 times to harvest, and ammonium sulfate should be applied 20-30 jin per mu each time, and appropriate potassium fertilizer should be applied. The optimum temperature for onion bulb expansion period is 20-26 ℃. When it exceeds 26 ℃, the plastic film should be removed in time combined with weeding.

VII. Prevention and control of diseases and insect pests

40% dimethoate EC 800 times solution can be used to control latent leaf pests, double Bordeaux solution can be used to control onion purple spot, 70% methyl topiramate 600 times solution, or 60% ethyl phosphate aluminum 500 times solution can be used to control downy mildew.

VIII. Timely harvest

When the plant lodging, the lower 3-4 old leaves begin to turn yellow, and when the outer layer of the bulb is dry, you can choose to harvest in sunny days, spray 400 times of chlorophyllin half a month before onion harvest, and stop watering 10 days before harvest.