Cabbage. capitata L .)
Brassicaceae, Brassica. It is a variety of cabbage.
Referred to as cabbage, also known as cabbage, cabbage, cabbage, fennel and so on.
Originated from the Mediterranean coast, it was introduced to China in16th century. Chinese cabbage has the characteristics of cold resistance, disease resistance, strong adaptability, easy storage and transportation, high yield and good quality. It has been widely cultivated in all parts of China, and is one of the main vegetables in northeast, northwest and north China in spring, summer and autumn.
Biological properties
(1) Botanical characteristics: Chinese cabbage is a biennial herb, and its roots are mainly distributed in the soil layer within 30CM. Stem shortening is divided into inner shortened stem and outer shortened stem. Cauline lotus leaf with shortened outer part and cauline bulbous leaves with shortened inner part. The leaves of cabbage include cotyledons, basal leaves, seedling leaves, lotus leaves and bulbous leaves. The leaves are dark green to green, smooth and fleshy, and there is powdery wax on the leaves, which can reduce water transpiration, so Chinese cabbage has stronger drought resistance than Chinese cabbage. Flowers are racemes, cross-pollinated, and all varieties and varieties of cabbage cross each other. The fruit is silique, the seeds are spherical, reddish brown or dark brown, and the 1000-grain weight is about 4G.
(2) Growth and development: In general, the seeds of northern Chinese cabbage are harvested in autumn, and the leaves are formed in the first year to complete vegetative growth, vernalization is completed through low temperature in winter, and photoperiod flowering and fruiting are completed through long sunshine in the next spring. Its growth process is basically the same as that of Chinese cabbage. However, the days required for each growth period are longer, and the germination period needs 8- 10 days. The seedling stage is 25-30 days; The cluster stage is 20-25 days for early-maturing varieties and 30-35 days for middle-late-maturing varieties; Heading stage takes 20-25 days for early-maturing varieties and 30-50 days for mid-late-maturing varieties.
Cabbage is a kind of crop that grows vigorously in winter. The transition from vegetative growth to reproductive growth requires strict environmental conditions. It requires seedlings to grow to a certain size before they can be induced by low temperature, and vernalization can be completed in 50-90 days at 0- 12℃. Regarding the photoperiod, the varieties of pointed and flat heads are not very strict, and the varieties of ballpoint pens require long sunshine. After entering the reproductive growth period, it usually goes through bolting, flowering and fruiting. The flowering period is 30-40 days, and the fruiting period is 40-50 days.
Before heading, Chinese cabbage meets the requirements of vernalization at low temperature or seedling stage. Once the long sunshine condition is met after planting, it may appear "immature bolting" phenomenon, which hinders the formation of leaf bulbs and reduces the yield. In recent years, raising spring cabbage in improved greenhouse or plastic greenhouse not only avoids low temperature, but also greatly shortens the seedling raising period, which has a good effect on preventing immature bolting and ensuring early maturity and high yield.
(3) Requirements for environmental conditions: The requirements of Chinese cabbage aunt for environmental hype are basically the same as those of Chinese cabbage, but they are more adaptable and resistant than Chinese cabbage.
Cabbage likes mild climate and can resist cold and high temperature. The suitable temperature for heading stage is15-20 C, but the adaptive temperature range is 7-25 C. Seedlings can tolerate low temperature of-15 C and high temperature of 35 C. Cabbage needs sufficient soil moisture and moist air. If the soil is dry, it will affect the pilling and reduce the yield. Cabbage is a perennial crop with wide adaptability to light intensity, and its light saturation point is 30000-50000 LX. Cabbage is a fertilizer-loving and durable crop, which absorbs more fertilizer, requires more nitrogen fertilizer at seedling stage and heading stage, and requires more phosphorus and potassium fertilizer. The ratio of absorbing nitrogen, phosphorus and potassium during the whole growth period is about 3: 1:4. Every 1000KG of leaf bulb absorbed 4. 1-4.8 kg of nitrogen, 0. 12-0. 13 kg of potassium. On the basis of full application of nitrogen fertilizer, the combined application of phosphorus and potassium fertilizer has obvious yield-increasing effect.
Types and varieties
According to the shape of bulbs and maturity, cabbage can be divided into three basic ecotypes:
(1) pointed type: the tip of the leaf ball is pointed, similar to a heart. Most of them are early-maturing and early-middle-maturing varieties, and it takes 50-70 days from colonization to leaf bulb maturity. Representative varieties are chicken heart cabbage, bovine heart blue and so on.
(2) Round-headed type: the leaves are spherical, and most of them are early-maturing and early-middle-maturing varieties. It takes 50-70 days from planting to harvesting, with few outer leaves and tight leaves. The representative varieties are Jinzaosheng, Jingzaoshu, Shaanxi 1 and Jin Mu 84.
(3) Flat-headed bulbs are oblate, and most of them are middle-limited or late-maturing varieties, and it takes 70- 100 days from planting to harvesting. The representative varieties are flat-headed black leaves, yellow seedlings and Zhangjiakou fennel.
Since 1950s, cabbage hybrids have been widely used in Japan and some countries in Europe and America. Since 1970s, heterosis breeding of Chinese cabbage has developed rapidly, and many suburban hybrids have accounted for 40-90% of the total planting area of Chinese cabbage. At present, excellent single anal hybrids are Jingfeng 1, Xia Guang, Baochun, Qingfeng, Feng Wan, Zhonggan 1 1 and so on.
cultivation techniques
(1) Chinese cabbage has strong adaptability in the cultivation season, which is both cold and heat resistant. It can be cultivated in the open field in spring, summer and autumn in northern China. There are many seedlings in spring and summer in the cold regions of Northeast China, Northwest China and North China, and autumn harvest in summer sowing. With long growth period and large leaves, it is the main producing area of Chinese cabbage. North China and some cities in northeast and northwest China are mainly cultivated in spring and autumn, and multiple cropping can also be carried out. Seedling raising in winter and spring, planting in spring and harvesting in summer are called summer cabbage; Seedling raising in summer, cultivation in autumn and harvest in autumn and winter are called autumn cabbage.
(2) Seeding and transplanting are adopted in the cultivation of Chinese cabbage. Most spring cabbages are planted early. In the northeast, northwest, Inner Mongolia and other cold areas, greenhouse seedling raising is usually carried out in February and March, and the seedling raising period is 60-80 days. There are two ways to raise seedlings in North China: one is to raise seedlings in sunny border from mid-February to1early October with 65438+, and sow in February-March. Secondly, in February, seedlings were raised in plastic greenhouses for 40-50 days; Autumn cabbage is bred from June to July, and the breeding period is generally 35-40 days; Summer cabbage breeds in April-May, and the breeding period is 30-40 days.
(3) Planting and Density When the soil temperature is above 5℃, Chinese cabbage and roots begin to move. Therefore, spring Chinese cabbage can be planted when the daily average temperature is above 6℃. In northern China, flat cultivation is mostly used in spring drought, and soil should be brought as much as possible in summer when it is hot and rainy, so as to avoid damaging roots. Water should be used to survive after planting.
Reasonable close planting is one of the important technical measures to increase yield. The suitable nutritional area of Chinese cabbage should be determined according to the variety and growth period. The number of plants per mu and the spacing between plants are roughly as follows: early-maturing varieties: 33-40 cm square, 4000-6000 plants per mu; Medium-mature varieties: 45-50 cm square, 2500-3000 plants per mu; Late-maturing varieties: 60-65 cm square, each plant 1500- 1800 plants.
(4) Fertilizer and water management After planting Chinese cabbage, water the seedlings slowly. At this time, due to the low temperature, it is necessary to intertillage and loosen the soil in time after watering, so as to preserve soil moisture and improve ground temperature, and promote the recovery and growth of roots. When entering the rosette stage, plants should form strong assimilation organs and absorb more water and fertilizer, so they can be topdressing for the first time, and apply nitrogen fertilizer 15-20kg per mu to fully supply water and promote the growth of leaf bulbs. After bulbs are formed, watering should be controlled to prevent the sun from cracking and facilitate storage.