Cultivation techniques of purple cabbage in spring open field

Purple cabbage has good cold resistance, compact heading, bright color, strong adaptability, high yield, good quality and high planting benefit. It is suitable for cultivation in open field and protected field. The yield per mu is generally 2500-3000 kg. In this paper, the key techniques of spring open field cultivation are introduced as follows:

First, cultivate strong seedlings

1. Variety selection. The early maturing variety "Zaohong" which is suitable for spring open field cultivation introduced from the Netherlands can be selected with purplish red leaves, oval leaf balls and a single ball mass of 0.75 1kg. It takes about 65 to 70 days from planting to harvest.

two。 Sow seeds at the right time. Spring open field cultivation can raise seedlings in protected field from the middle of January to the first and middle of February, sow dry seeds and raise seedlings in nutrition bowl. Fully water the nutritious soil before sowing and cover the soil 1.5 cm thick after sowing. Then cover the film to promote the early development of strong seedlings.

3. Seedling management. Generally, the seedling age is 70-90 days, and the 2 true leaves appear 20-30 days after sowing. During the emergence period, the daytime temperature was about 25 ℃, and the nighttime temperature was 15 ℃. After all the seedlings came out, the temperature was reduced to 20 ℃ in the day and 10 ℃ at night. It takes 45-60 days for seedlings to grow from 3 true leaves to 6-8 true leaves. Low temperature exercise was carried out before planting, which was kept at about 15 ℃ in the daytime and 7 ℃ ~ 8 ℃ at night, which was gradually close to the temperature of the open field. The standard of strong seedling is: 6 to 8 true leaves, short internodes, thick leaves, deep color, stout stems and well-developed roots.

II. Soil preparation and fertilization

Purple cabbage likes fertilizer, and the base fertilizer generally applies 5000 kg of high-quality ring fertilizer, 15 kg of diammonium phosphate and 15 kg of potash fertilizer per mu. It is generally made into a flat bed of 1 to 1.2 meters.

III. Colonization

Cultivation in the open field should not be early to avoid immature bolting. It is generally planted after Ching Ming Festival in spring and the temperature is stable above 6 ℃. Adopt "water to stabilize seedlings", the amount of water is not easy to be too large, in order to slow down the seedlings. The planting density is 50 cm × 50 cm, with 2500 plants per mu and 2600 plants per mu. The planting depth is based on the leaves left above and the heart leaves not buried in the soil. If the improved plastic film mulching cultivation is adopted, it can promote early maturity and high yield.

IV. Field management

Purple cabbage needs a large amount of fertilizer, which is topdressing for 4 times in seedling stage, rosette stage and pericardium stage. Among them, the rosette stage and pericardium stage need the largest amount of fertilizer, which should be re-applied. Slow seedling water was irrigated once after slow seedling. 15 kg urea per mu was applied 10-15 days after slow seedling. The second topdressing was carried out in the middle stage of rosette, with 15kg urea, 20kg diammonium phosphate and 10kg potash fertilizer per mu. From planting to the late stage of rosette for 30-40 days, the inner closure of heart leaves indicates that it has reached the heading stage, which is the period of the fastest growth and the largest growth of purple cabbage, and it is also the period when the amount of fertilizer and water is the largest. Therefore, the heading period should be combined with watering and topdressing for 2 to 3 times, each mu of diammonium phosphate 10: 15 kg, and a small amount of chemical fertilizer in the later stage, especially not too much fertilizer and water before harvest, so as to avoid cracking.

Pang Qiujuan, Agricultural Bureau of Pingxiang County