What are the pollution-free cultivation methods for purple cabbage?
How is purple cabbage cultivated in a pollution-free way? Please provide technical guidance. Purple cabbage is also known as red cabbage and purple cabbage. It is a variety of the cabbage species in the Brassicaceae family, Brassica genus, that can form a purple leaf head, and it is a biennial herbaceous plant. It originated along the Mediterranean coast. Its purple leaf head is the edible organ, and it contains various vitamins and minerals, especially...
How is purple cabbage cultivated in a pollution-free way? Please provide technical guidance.
Purple cabbage is also known as red cabbage and purple cabbage. It is a variety of the cabbage species in the Brassicaceae family, Brassica genus, that can form a purple leaf head, and it is a biennial herbaceous plant. It originated along the Mediterranean coast. Its purple leaf head is the edible organ, and it contains various vitamins and minerals, especially rich in vitamin C. Therefore, although purple cabbage has not been cultivated and eaten in China for long, it quickly became highly favored because of its rich nutrition and beautiful color. Wuji County has been growing purple cabbage since 2001, and it has now been cultivated for 6 years. Through several years of practice, some cultivation experience has been accumulated.
1. Cultivation season and crop rotation arrangement
Purple cabbage likes a mild climate, but it also has cold resistance and heat tolerance. The suitable temperature for seed germination is 18-22°C, and it can also germinate under high-temperature conditions of 25-30°C. The optimum temperature for outer leaf growth is 20-25°C. The optimum temperature for head formation is 15-20°C. In Wuji County, it can be cultivated in both spring and autumn. For spring cultivation, seedlings are generally raised in a greenhouse at the end of January and transplanted to open fields at the end of March; for autumn cultivation, seedlings are generally raised under shade at the beginning of June and transplanted to open fields in mid-July.
2. Cultivation management
1. Select suitable varieties for cultivation. At present, most varieties are introduced from abroad. The main variety grown in our county is Purple Cabbage No. 1. This variety is a mid-maturing variety with a relatively large plant type and relatively strong growth vigor, a spread of 65-70 cm, 18-20 outer leaves, and a purplish-red leaf color with a relatively heavy waxy coating on the underside. The leaf head is round and spherical, with a single head weight of 2-3 kg and a yield of 3000-3500 kg per mu. It takes about 80-90 days from transplanting to harvest, and it has relatively strong storage quality and disease resistance. It is suitable for protected cultivation in spring, open-field cultivation, and open-field cultivation in summer and autumn.
2. Land preparation and bed making. Purple cabbage has a strong ability to absorb fertilizer. The land should be deeply plowed, and after leveling, beds 1-1.2 m wide should be made. Apply 5000 kg of organic fertilizer, 25-30 kg of phosphate fertilizer, 30-40 kg of urea, and 20-30 kg of potash fertilizer per mu. Calcium content in purple cabbage is second only to nitrogen. If calcium is deficient, tipburn may occur, so a portion of calcium fertilizer should also be appropriately supplemented.
3. Sowing and seedling raising. Purple cabbage is generally cultivated by raising seedlings and transplanting. When sowing seedlings, broadcast sowing is used, with 50-100 g of seed per mu. After emergence, the temperature should be kept at 15-20°C during the cotyledon stage and 18-22°C during the true leaf stage, and 5-7 days before transplanting it should gradually approach the outside temperature. Spring purple cabbage is transplanted to open fields at the end of March and the beginning of April. Planting with water helps increase soil temperature and helps seedling recovery; when transplanting autumn-sown purple cabbage, it can be planted first and then irrigated to help preserve soil moisture. For early-maturing varieties, the plant spacing is 50 cm x 50 cm, with 2500-2600 plants per mu; for mid-maturing varieties, the plant spacing is 50 cm x 60 cm, with 2200 plants per mu.
4. Seedling stage management. Before sowing, the seedbed should be irrigated thoroughly with bottom water, and when pricking out and transplanting, water should be applied thoroughly to avoid root damage; apart from that, watering should be minimized.
5. Rosette stage management. After watering 1-2 times for seedling recovery, the plants enter the seedling hardening stage. During this period, cultivate 2-4 times. The first cultivation should be deep and thorough to help preserve soil moisture and promote root growth; during the middle rosette stage, cultivation should be shallow and combined with earthing up to promote more roots on the outer shortened stem and benefit head formation. Seedling hardening lasts about 20 days. By the late rosette stage, when head formation begins, a large amount of irrigation should be applied.
6. Head formation stage management. During this period, the leaf head grows quickly and has a high water requirement. Generally, water whenever the ground looks dry, until harvest.
7. Harvest. Harvest when the leaf head has become quite firm. When harvesting, cut off the root base and remove the outer leaves and damaged leaves so that the leaf head is clean and free of soil.
8. Pest and disease control.
(1) Diseases. During the seedling stage, prevent damping-off disease, appropriately control moisture, and provide more ventilation and light. During the head formation stage, mainly prevent soft rot, especially in summer and autumn. Prevent waterlogging, and promptly pull out diseased plants. Spraying 100-150 mg/kg agricultural streptomycin has a certain control effect. During the head formation stage, tipburn is also likely to occur, so soil moisture should be maintained to facilitate calcium absorption. In addition, spraying some calcium on the leaves also has a certain control effect.
(2) Insect pests. Mainly aphids and cabbage caterpillars. Aphid control: promptly remove weeds, leftover plants, and dead leaves. You can use 50% pirimicarb wettable powder or imidacloprid 1000-fold solution for spraying. Control of cabbage caterpillars: avoid continuous cropping or interplanting with vegetables of the same family. For chemical control, pyrethroid pesticides can be used.
Click to get more cabbage cultivation techniques
Click to get more vegetable cultivation techniques