Cultivation and Management Techniques for Autumn Chinese Cabbage
Chinese cabbage is a main vegetable for winter and spring, and it is also the main crop succession of Chinese cabbage. Therefore, growing autumn Chinese cabbage well is of great importance. In production, the main reasons affecting the high yield of Chinese cabbage are the many disastrous weather events during the growing season and the severe occurrence of diseases (mainly viral disease, downy mildew, and soft rot). Therefore, in production, efforts must focus on controlling the three major diseases to improve the high and stable yield of Chinese cabbage.
????I. Variety Selection
There are many varieties of Chinese cabbage, which can be divided into three basic ecological types: the cylinder type, the original-head type, and the oval type. However, due to the growing season, medium-to-late-maturing varieties that are disease-resistant, cold-tolerant, high-yielding, and storage-tolerant must be selected. The main excellent varieties include: Lubai No. 3, Shandong No. 2, Shandong No. 5, Fengkang 85, and others.
????II. Sowing Time
Under normal circumstances, sowing 3 to 5 days before or after the Start of Autumn is appropriate, and in high-temperature years it can be postponed to mid-August. Disease-resistant, late-maturing varieties with a long growing period can be sown appropriately earlier, while medium-maturing varieties with a short growing period can be sown appropriately a few days later.
????III. Preparatory Work Before Sowing
Chinese cabbage cannot be grown continuously, nor can it be rotated with other cruciferous vegetables; this is one of the important measures for preventing pests and diseases. After the previous crop is harvested, timely tillage and loosening of the soil should be carried out. Combined with plowing, 8000 to 10000 kg of barnyard manure and 75 to 100 kg of nitrogen-phosphorus-potassium compound fertilizer can be applied per mu as base fertilizer, then the field should be leveled.
????IV. Planting Techniques
1. Sowing. Sowing is divided into direct sowing and seedling transplanting, generally depending on whether the previous crop is harvested early or late. If the previous crop is harvested early and the field can be prepared and beds made in time, the direct sowing method can be used. Otherwise, the seedling transplanting method is used. Direct sowing is done 5 to 6 days later than seedling transplanting. Chinese cabbage cultivation generally adopts two modes: high ridges and flat beds. High ridges generally have one row per ridge, with a ridge height of 12 to 15 cm; flat beds have two rows per bed, and the bed width depends on the variety. Direct sowing has two methods: hole sowing and drill sowing. Hole sowing means opening holes within the row or on top of the ridge at a certain plant spacing. For early-maturing varieties, the row spacing is 55 to 60 cm, the plant spacing is 40 to 50 cm, and about 3000 plants are planted per mu; for medium-to-late-maturing varieties, the row spacing is 65 to 70 cm, the plant spacing is 55 to 60 cm, and about 2500 plants are planted per mu. The holes are 8 to 10 cm long and about 1 to 1.5 cm deep, with 5 to 6 seeds sown per hole, using about 0.15 kg of seed per mu. Drill sowing means opening furrows 5 to 10 cm deep according to the row spacing, first watering along the furrows, and after the water seeps in, evenly scattering the seeds in the furrows and covering them with 0.8 to 1 cm of fine soil. The seeding rate is about 0.3 kg per mu. For directly sown Chinese cabbage, after the young buds emerge, frequent light watering should be adopted to keep the ground moist and lower the surface temperature. When there is no rain, generally water once on the day of sowing or the next day, making sure to soak the ridge surface thoroughly. On the third day after sowing, water a second time to promote the emergence of most young buds.
2. Seedling stage management. This refers to management from the emergence of young buds to the rosette stage. At this time, thinning should be done in time, and at the 2 to 3 true-leaf or 4 to 5 true-leaf stages, thinning should be carried out once each, while removing weeds, diseased seedlings, and weak seedlings. When there are 6 true leaves (rosette stage), the seedlings should be finally thinned, and timely cultivation should be carried out. Once the outer leaves close over the rows, cultivation should stop to avoid damaging roots and leaves. Cultivation should be shallow rather than deep. Directly sown plants are generally established when they have 5 to 6 true leaves.
3. Transplanting and establishment. The seedling age is generally 15 to 20 days, and when the seedlings have 5 to 6 true leaves, this is the best period for transplanting. Transplanting is best done in the afternoon. The appropriate density should be determined according to the characteristics of the variety. Water immediately after planting. After that, water once each morning and evening every day for 3 to 4 consecutive days to help the seedlings recover and survive.
????V. Fertilizer and Water Management
1. Topdressing. Chinese cabbage has a high yield and a large fertilizer requirement. On the basis of applying sufficient base fertilizer, topdressing should not be delayed. Topdressing should be determined according to different growth stages and seedling conditions. Generally, no topdressing is applied at the seedling stage. If the base fertilizer is insufficient, the first application can be made at the 3 to 4 true-leaf stage, applying 10 kg of ammonium sulfate per mu, broadcast on both sides of the seedlings, and watered immediately; this is called the "seedling-promoting fertilizer." The second application is after final thinning or after seedling transplanting, applying 15 to 20 kg of ammonium sulfate per mu in furrows opened on both sides of the ridge; this is called the "plant-developing fertilizer." The third application is at the rosette stage, applying 25 to 30 kg of ammonium sulfate and 10 to 15 kg of superphosphate per mu, placing the fertilizer into furrows or holes, then adding a little soil to support the ridge, and then watering; this is called the "heavy topdressing." The fourth application is at the mid-heading stage, applying 15 to 20 kg of ammonium sulfate per mu, which can be applied with irrigation water; this is called the "heart-filling fertilizer."
2. Watering. From the rosette stage to the rosette stage of Chinese cabbage, the temperature gradually declines and the weather is mild. During this period, watering can be done appropriately. At the late rosette stage, water can be controlled appropriately for several days, and watering should resume after the third topdressing. After Chinese cabbage enters the heading stage, its water requirement is greatest. Therefore, as soon as the seedling-holding period ends, a thorough watering should be given. Then, after 2 to 3 days, a second watering should follow. This one is very important, because if the soil cracks at this time, the lateral roots will break and the fine roots will die, affecting head formation. After that, generally water once every 5 to 6 days to keep the soil moist.
VI. Leaf Binding and Harvesting
In the late growth period of Chinese cabbage, the weather is changeable and the temperature gradually declines. To prevent frost damage, binding should be done in time. Generally, 10 to 15 days before harvest, watering should be stopped, the rosette leaves should be lifted up and gathered around the head, and then the leaves should be tied with soaked sweet potato vines or cereal straw. This makes the head firmer and allows it to continue growing. Two to 3 days before Minor Snow, it should be harvested in time and dried in the field; once the outer leaves wilt, it can be stored. Zhao Yinghui