Key points of field management of Chinese cabbage in autumn

Chinese cabbage, biennial herb, 40-60 cm tall, often glabrous throughout, sometimes with a few bristles on the midrib below the leaves. Native to northern China, it is a leafy vegetable of Brassica in the cruciferous family, usually referring to Chinese cabbage; it also includes Chinese cabbage and cabbage, namely "cabbage" or "cabbage", a cultivated variety of cabbage. It is introduced to the south and cultivated in all parts of the north and south.

Morphological characteristics of Chinese cabbage Chinese cabbage is a biennial herb, 40-60 cm high, the whole plant of Chinese cabbage is glabrous, and sometimes there are a few bristles on the midvein below the leaves. Basal leaves numerous, large, Obovate-oblong to broadly Obovate, 30-60 cm long, less than half the width, apex obtuse, margin wrinkled, undulate, sometimes with inconspicuous teeth, midvein white, very broad, with many stout lateral veins; petiole white, flat, 5-9 cm long and 2-8 cm wide, margin with notched wide wings. Upper cauline leaves oblong-ovate, oblong-lanceolate to long-lanceolate, 2.5-7 cm long, apex obtuse to shortly acute, entire or toothed, stipitate or clasping, powdery. Flowers bright yellow, 1.2-1.5 cm in diam.; pedicels 4-6 mm long; sepals oblong or ovate-lanceolate, 4-5 mm long, erect, light green to yellow; petals Obovate, 7-8 mm long, base narrowed into claws. Siliques stout and short, 3-6 cm long, ca. 3 mm wide, flattened on both sides, erect, beak 4-10 mm long, 1 mm wide, apex rounded; fruiting pedicels spreading or ascending, 2.5-3 cm long, thicker. Seeds globose, 1-1.5 mm in diam., brown. Flowering in May and fruiting in June. Chinese cabbage, Brassica napus of Cruciferae, originated in northern China, is a traditional vegetable in China. Chinese cabbage was first called song, but Isatis indigotica is not exactly today's cabbage. Modern cabbage is generally divided into Chinese cabbage and Chinese cabbage. Northerners generally call Chinese cabbage "cabbage" and Chinese cabbage is called "rape". Autumn is the key period of cabbage planting, the field management of autumn cabbage can not be underestimated, we must do a good job of scientific and standardized management, so what aspects of autumn field management of Chinese cabbage should start? First, it is necessary to fertilize Chinese cabbage with leaves as its products in time, and it is very sensitive to the requirements of nitrogen, phosphorus and potassium. Not only base fertilizer should be applied in production, but also topdressing should be carried out according to different growth periods. In the growing period, topdressing is mainly based on available nitrogen fertilizer, such as ammonium sulfate, ammonium bicarbonate, ammonium phosphate, urea and so on. The period of topdressing should be mastered well, which is generally divided into 4 times in seedling stage, rosette stage, heading stage and middle stage. Ammonium sulfate was applied 5 kg / mu at seedling stage, 1000 kg / mu at rosette stage, 15 kg / mu of ammonium bicarbonate or 10 kg / mu of ammonium sulfate at rosette stage, 25 kg / mu of ammonium bicarbonate or 15 kg / mu of ammonium sulfate at the beginning of heading, 1000 kg / mu of dilute manure, 10 kg / mu of ammonium carbonate or 1% urea solution.

Second, vegetable farmers attach great importance to the prevention and control of the three major diseases of Chinese cabbage, but often ignore the control of insect pests. In fact, the occurrence and spread of many diseases are inextricably related to pests. Aphids are the main culprits for the transmission of viral diseases, which can cause Chinese cabbage to shrink and die; soft rot bacteria are mainly transmitted through insects, Rain Water and irrigation water, infecting Chinese cabbage from wounds. The wound caused by pests is beneficial for bacteria to invade and cause disease. Good control of cabbage green insects, yellow striped beetles and underground pests and reducing insect wounds can effectively reduce the occurrence of soft rot of Chinese cabbage. Therefore, pest control is also an important measure to control diseases.

Third, to postpone bundling can prevent Chinese cabbage from frost, promote ambition and facilitate harvest. However, bundling should not be premature, because it is too early, the photosynthetic efficiency of outer leaves is greatly reduced, which hinders the normal growth of Chinese cabbage and is not conducive to the enrichment of leaf bulbs. Generally, 10-15 days before harvest, stop watering, lift the rosette leaves, hold the bulbs, and then tie the leaves with soaked sweet potato seedlings or cereal grass 3 to 5 centimeters from the top to make the core more solid and continue to grow.

Skills of fertilizer and water management of Chinese cabbage in autumn:

Topdressing Chinese cabbage has a high yield and needs a large amount of fertilizer. On the basis of applying sufficient base fertilizer, do not topdressing in time. Topdressing should be determined according to different growth periods and seedling conditions. There is no topdressing in the seedling stage. If the base fertilizer is insufficient, for the first time, 10 kg of ammonium sulfate per mu can be applied at the stage of 3-4 true leaves, sprinkled on both sides of the seedling, and immediately watered, called "seedling fertilizer"; for the second time, 15-20 kg of ammonium sulfate per mu is applied after seedling setting or seedling transplanting, which is called "hair fertilizer". The third time in the rosette stage, ammonium sulfate 25-30 kg per mu, superphosphate 10-15 kg, fertilizer into the ditch or hole, and then slightly add soil to help ridge, and then watering, called "big topdressing"; the fourth time in the middle of heading, ammonium sulfate 15-20 kg per mu, can be flushed with water, called "heart-filling fertilizer".

Watering Chinese cabbage from the group plant to the rosette stage, the temperature drops day by day, the weather is mild, can be properly watered during this period, and the water can be properly controlled for several days at the end of the rosette, and then watered after the third topdressing. After entering the heading stage, Chinese cabbage needs the most water, so it is necessary to water the squatting seedlings once. Then water it a second time every 2-3 days. This time is very important, when the soil is dry and cracked, the lateral roots will be broken, the fine roots will die, and the pilling will be affected. After that, water is usually watered once every 5-6 days to keep the soil moist.