Origin and distribution
Plum blossom originated in the mountainous area at the junction of China, Sichuan and Hubei. There are also wild species of plum blossoms in Hehuanshan II, 27523 1 and Hsinchu in Taiwan Province Province, China. China was the first to be cultivated. For example, in the Book of Songs Zhao Nan, it is recorded that "there are plums, but there are actually seven baskets", which means that when plums fall, seven tenths of the fruits on the trees are taken from the baskets; Later, in Shan Hai Jing, Er Ya and other ancient books, there were all records about Mei. Li has been cultivated in China for at least 3000 years. Li has been introduced to Japan and Korea since ancient times. It was widely cultivated in Japan in the Nara era and is now eaten in large quantities. Li is mainly distributed in the Yangtze River Basin, Southwest China, South China and Taiwan Province Province, and less in the north of the Yangtze River. Apart from China, the world is limited to Japan and South Korea: Europe and the United States have almost no cultivation, just for viewing.
Features and characteristics
There are different types of plum varieties, but they have common characteristics in morphological characteristics and fruiting habits.
morphological character
The crown is open or round. The bark is rough, grayish green and slightly black. The new shoots are green, sometimes dark red on the sunny side. The leaves are oval, wedge-shaped at the base, 4 ~ 10 cm long, slender and sharp at the apex, with thin and sharp serrations at the leaf margin, pilose on the surface and back of the leaves, or only born in the midvein on the back of the leaves; Petiole short, cylindrical. Flowers are bisexual, pedicels are short, white, reddish or red, and fragrant. Single valve usually has 5 valves, 6-7 valves, and double and semi-double valves have 25-30 valves. Stamens are 40 ~ 70, pistil is usually 1, and there are 2 ~ 3 varieties with double petals and 3 ~ 7 varieties: incomplete flowers with degenerated pistil or incomplete development; Sepals 5, greenish red, green or red. The fruit is spherical or oval; Light green or yellow, and some varieties on the sunny side are light brown or deep red; Shallow suture; Sticky core with small shallow pits on the surface (see figure).
Growth and fruiting habits Grafted trees begin to bear fruit in 2 ~ 3 years, seedling trees begin to bear fruit in 5 ~ 7 years, and 10 ~ 15 enters the full fruit stage. The plant yield can reach more than 50 kg (450 plants/hectare), and it will gradually decrease after 50 years. Longevity, with 100-year-old trees. Extremely short fruit branches (below 3 cm in length) have high proportion of complete flowers and high fruiting strength, which leads to weak branches and short life span, especially branches below 1 cm, which often die after fruiting; Short fruit branch (3 ~ 10 cm) has the highest proportion of complete flowers and the strongest fruiting ability, and can bear fruit repeatedly in the same year, which is the main fruiting branch of plum tree. The middle fruit branch (10 ~ 20 cm) has a high proportion of complete flowers, and its fruiting strength is not as good as that of very short fruit branches, which can produce fruit branches again in the same year. Long fruit branches (more than 20 cm) have low flowering rate and poor fruiting strength. If the axillary bud is a single bud, it can be a leaf bud or a flower bud; In the case of multiple buds, there are 2 ~ 3 buds, which are composed of flower buds and leaf buds. Hidden buds are long-lived and easy to germinate, so they are easy to renew and rejuvenate, which is also a major reason for the longevity of plum trees.
phenophase
In Zhejiang province, the flower buds began to swell in mid-June from May 438 to February, and began to blossom in mid-February of the following year, and from late February to early March. Due to different years, the flowering period varies greatly, with a difference of 40 days. Leaves spread out in early April, and shoots are picked in the first half of April. The old and weak trees reached the growth peak in mid-April, the young trees in mid-May, and the new shoots stopped growing in the middle and late June. The shoots can be picked 1 ~ 3 times a year, and the leaves will fall at the end of 10. Fruit growth can be divided into three periods: the first rapid growth period, about the middle and late April; The second slow growth period or hard core period is from late April to early May; The third rapid growth period or pre-ripening period, especially 7 ~ 10 days before maturity, grows extremely fast and matures gradually. In the first half of July, flower buds began to differentiate.
Requirements for environmental conditions
Plum is suitable for warm and humid climate, and can be cultivated economically in the area with annual average temperature 13.7 ~ 23℃. The flower organs are frozen below -6℃, and the development of young fruits is blocked below -3℃. The suitable temperature for complete flowering is 10 ~ 15℃. The requirements for soil in Xixia wetland zone are not strict, but it must be well drained and the soil layer is deep. It is best to lean south or east. The optimum pH value of soil is 5.5 ~ 6.5, and the growth below 4.5 and above 7.5 is obviously poor or even dead.
principal item
Divided into Bai Mei, Mume and Plum.
Baimeiban
The fruit is green when it is immature, yellow and white when it is mature or fully mature. Coarse in quality, bitter in taste, big in stone and the worst in quality. It is used to make prunes. It matured in the first half of May and is rarely cultivated now. The varieties are Dabaitoumei in Chaoshan, Hangzhou, Zhejiang, Taigongmei in Guantang, Chaoan, Guangdong and so on.
green plum
The fruit is green when it is immature and about to mature, yellow-green when it is mature, round in cross section and medium-high in quality. Suitable for making sugar plum and plum wine, the yield is not as high as plum blossom. Most mature in early June. The varieties are Fine Plum, Big Leaf Plum and Shengdi Plum in Yuhang, Big Plum and Small Plum in Wuxian, Jiangsu, and Tonglu Plum in Yuanjiang, Hunan.
Chinese plum
The fruit is green when it is immature, but it is red on the sunny side. When it is mature or fully mature, the red color will deepen to purple, sometimes accounting for 2/3 of the whole fruit surface. The cross section of the fruit is oval, and the quality is medium to high. Suitable for making plum and so on. Compared with Prunus mume, the disease resistance is poor, and the fruit is easy to crack before maturity, and it usually matures in mid-June. The varieties are lobular pig liver plum, big leaf pig liver plum and leaf plum in Yuhang, Zhejiang, red plum and small red plum in Wuxian, Jiangsu, and rouge plum in Yuanjiang, Hunan.
Key points of cultivation techniques
type
Methods There are seedling propagation and grafting propagation, and grafting propagation is the best. The rhizome is plum or peach. (1) Plum rootstock grows fast at the initial stage, but its fruiting age is later than that of peach rootstock 1 ~ 2 years. Strong grafting affinity, vigorous seedling growth, long life, less pests and diseases, strong waterlogging tolerance, good fruit quality and more juice. But the xylem is hard, and the grafting operation is more difficult than peach rootstock. ② Peach rootstocks grew rapidly in the early stage, bearing fruit as early as 1 ~ 2 years. However, the grafting affinity is weak, so the grafting interface must be buried underground for cultivation to promote the rooting of the scion and form two layers of roots. If the 3-year-old plum tree does not take root by itself, the rootstock will be thinner than the scion, and after 4-5 years, it will grow weak, even the tree will become old, the yield will be reduced and the life span will be shortened. The method of forming double-layer roots is to make use of the advantages of plum root and peach rootstock and overcome their disadvantages. Cutting before germination in spring, and bud grafting or T-bud grafting from late August of 10 to early October of 10. Because the wound heals slowly, it will take at least 1 month to wrap it up after grafting.
plant
It can be built piecemeal or in blocks. Plum varieties with thick meat, small stone, high flowering rate, high yield and disease and insect resistance should be selected for planting. Most varieties of plums are self-flowering, so two or three varieties must be planted together. Generally, the plant spacing is 3 ~ 5 m× 4 ~ 6 m, and it is suitable to plant in 65438+February after defoliation. After planting, attention should be paid to drought prevention. Trees that fail to germinate and grow in time in the next spring must be cut back to the living parts. Otherwise it will continue to dry up and die.
Plastic trimming
Mei Xiguang, commonly used in natural jubilation. When shaping young trees, due to the short internodes of branches, the main branches should be selected in time, the distance in the layer should be widened and the taper of branches should be reduced; The opening angle of the main branch should be 40 ~ 45 degrees: the length of the extended branch is generally 50 ~ 60 cm, which is easy to sag if it is too long. Light cutting and long putting are easy to form fruiting branches. For short fruit branches and very short fruit branches, they are generally not cut short; Long fruit branches are pruned together and developed together. When pruning, the aging fruiting branches are updated every year by taking the fruiting branches as the unit, and the developing branches germinated by hidden buds are cultivated into new fruiting branches by light pruning and long release. In the crown, starting from the developing branches, arrange 1 ~ 5-year-old fruiting branches in each part, and make them into a group, which will be updated and cultivated every year to keep the stable number and strong fruiting strength of the branches. Because the hidden buds are easy to germinate, they must be applied repeatedly in April-May. Large fruit varieties can be thinned immediately after the second fruit drop. Thinning after harvesting in June and July.
soil management
First of all, we must manage the topsoil. Intercropping young trees in rows can plant short crops such as beans; After 4 years, it is best to plant grass or green manure crops between rows, and cover the grassland with trees in dry season. Plum trees are very sensitive to soil moisture, especially in the hot and dry season from July to August. If the soil is short of water, the leaves are prone to wilting and even falling leaves, so we should pay attention to drought prevention. Plum is a fruit tree with high potassium requirement, and the annual application amount should be about 20% more than that of nitrogen fertilizer.
Eliminate pests and diseases
① Spherical Crustacea. Hurt the young branches. Manually scrape or spray 5% diesel emulsion in winter; Spraying 0.2 ~ 0.3 degree sulfur mixture or malathion emulsion 1000 times at the peak of nymph occurrence. ② Aphids. Damage to shoots and leaves. Spraying organophosphorus pesticides for 2 ~ 3 times at the early stage of leaf development. Dimethoate emulsion is prohibited. ③ Colletotrichum gloeosporioides. Will lead to early defoliation. Use carbendazim before onset; Tobuzine or 0.3 ~ 0.4 degree stone sulfur mixture. ④ Gypsum disease. Parasitic on the bark, weakening the tree. Scrape off the mycelial membrane and spray 5 degrees of stone sulfur mixture. ⑤ Scab disease (also called scab disease and black spot disease). Mainly harmful to fruits. Clear the source of the disease. Spraying sulfur mixture before flowering (5 degrees) and after leaf spreading (0.3 ~ 0.4 degrees), or using zineb and Tobuzin for control.
choose
Determine the harvest period according to the processing purpose. Sugar plums and dried plums were harvested in the tender plum period when the kernel just hardened, and harvested in Jiangsu and Zhejiang provinces in May1May to May 20. For plum production, the fruit has just withered and has not been harvested in Huang Shi in the green plum period, which is about 6 ~ 7 days later than the tender plum period; In order to make plums and purees, fruits should be harvested at Huangmei stage, when they are completely yellow, soft and mature. Conditional areas can harvest by stages to increase production. Hand picking is the best way to harvest.
economic value
Plum fruit has high nutritional value and is a good raw material for fruit processing. Can be made into a variety of processed products, such as plum wine, plum sauce, candied plum, sugar plum, preserved plum, Pei-Mui Chan, sour plum soup, etc., all of which are traditional foods. In addition, it is also a condiment for cakes and sweets. It is also widely used in medicine. Mume has the effects of relieving cough, dysentery, hangover, nausea and choking. Plum vinegar can be used as a mordant and will not fade for a long time. Flowers are ornamental, excellent garden tree species and good nectar source plants. Plum blossom is easy to cultivate and bears fruit early, which is suitable for the development of hilly and mountainous areas in the south of the Yangtze River.
medium method
See distant hybridization.