Detailed data of citrus fruit trees

The general name of citrus, kumquat and citrus. Fruit is rich in nutrition and has a unique taste. Besides fresh food, canned food, fruit juice, jam, fruit wine and candied fruit have become the main fruit processing products. Citric acid, essential oil and pectin extracted from it can be used as raw materials for food and pharmaceutical industries. Orange peel and orange collaterals are both Chinese herbal medicines. Flowers can be used to smoke scented tea and extract essence, which is also a good honey source. Citrus trees are evergreen and graceful, and can also be used for viewing.

Chinese name: citrus fruit tree kingdom: plant kingdom: dicotyledonous plants order: Sapindaceae: Rutaceae genus: citrus morphological characteristics, growth environment, distribution range, main species, cultivation techniques and morphological characteristics. Rootless roots propagated by layering or cutting. When the soil conditions are good, the lateral roots are numerous and widely distributed horizontally, and mycorrhiza often occurs. Fine roots on lateral roots have strong regeneration ability, and roots exposed on the soil surface are easy to take root and tiller. Many species and varieties have needles on their branches. Buds are compound buds. Generally, one leaf axil germinates new buds, and the rest is dormant. When the new shoots stop growing, the terminal buds will wither, which is a unique "self-shearing" phenomenon of citrus fruit trees. At this time, the lateral buds at the top replace the terminal buds, so the branches are often twisted. Ungerminated buds can maintain their germination ability for many years. This characteristic is often used in production to repair the incomplete crown or renew the old trees through the germination of * * * hidden buds. Compound leaves are composed of three leaflets, or "single compound leaves". Citrus and kumquat are evergreen trees, except Fructus Aurantii, which is deciduous. Perfect flowers, fragrant and developed nectaries. There are two types: single flower and inflorescence. The phenomenon of flower organ hypoplasia is common, and it is easy to produce fruits with few stones or no seeds. Sometimes parthenocarpy. There is an obvious dormancy period of Fructus Aurantii in winter, and kumquat and citrus grow almost every year. Generally, buds are picked 3-4 times a year. Spring shoots are neat, with the largest number, and some of them bear fruit in that year; Summer shoot is the main branch of young tree crown; Autumn shoots are mostly mother branches that bear fruit in the following year. On the basis of spring shoots, two or three buds can be regenerated. Winter buds are meaningless in production and should be erased as soon as possible. Most species bloom 1 time in spring every year, but lemon and citron can blossom and bear fruit all year round. Kumquat blooms continuously for 2-3 times every other month from June to July, and each flower can bear fruit. Citrus has a large amount of flowers, but the fruit setting rate is not high. Self-pollination is generally used for fertilization, but Shatian pomelo needs cross-pollination to improve its yield. It takes 6 ~ 14 months from flower withering to fruit ripening, which varies with species and varieties. The fruit is developed from syncarp, and the meat is pulpy, so it is called "citrus fruit". The exocarp and mesocarp are close together to form a tough pericarp, and the exocarp contains many oil cells; The mesocarp is spongy, and the boundary between mesocarp and exocarp is difficult to distinguish. The endocarp forms a sac (i.e., a locule), also known as a pulp sac, and a spindle-shaped juicy protuberance, called juice cell, is embedded in the sac, which is the main edible part of citrus (see figure). Seeds are usually polyembryonic, with only one sexual embryo, and the rest are unfertilized asexual embryos produced by nucellar cells, called nucellar embryos; Some species are monogamous. When multi-embryo seeds germinate, sexual embryos are often aborted, and seedlings are mostly developed from asexual embryos, which can maintain the basic characteristics of mother plant varieties, but it also brings difficulties to cross breeding. The chromosome number is generally 2 n = 18. Species and genera are easy to hybridize, and branches and buds are easy to mutate (bud change). Grafting compatibility is generally good, and it is possible to provide a wide range of rootstock and scion combinations to meet the needs of production or other special purposes. Growing environment Citrus plants originated in subtropical areas with high temperature and high humidity. The area where the annual average temperature is above 15℃ and the extreme low temperature is not lower than -7℃ is suitable for growing citrus. The areas with annual temperature above 17℃ and extreme low temperature not lower than -5℃ are suitable for planting citrus and grapefruit. Lemon and citron are suitable for areas with extreme low temperature not lower than -3℃. Citrus grandis and kumquat are native to continental climate zone and have strong cold tolerance. Kumquat can be planted in almost all places suitable for citrus production. Fructus Aurantii can withstand the low temperature of -23℃. Generally, it begins to germinate when the daily average temperature reaches 65438 03℃, and the optimum growth temperature is 23 ~ 365438 0℃, which weakens at 37℃ and stops at 39℃. Citrus requires annual rainfall of1000 ~1200mm, and the rainfall distribution is even. The requirements for soil are not strict, and the neutral to slightly acidic (pH 5.5 ~ 7.5) with deep soil layer and good drainage and ventilation is the best. Strong winds are bad for the growth and fruit of citrus. Distribution Scope Most of the important citrus varieties in the world are native to China. Two important species, Fructus Aurantii and Kumquat, are native to central and south-central China respectively. There are many kinds of citrus, which are distributed in the southern half of Asia and parts of Oceania, mainly in southern China and zhina, India, and to the northeast of India in the west. At present, the cultivation areas are distributed in tropical and subtropical areas between 40 north latitude and 40 south latitude, and the altitude is below 1000 meters; Economic cultivation is concentrated between 20 and 33 north latitude, and citrus is produced in more than 90 countries. In terms of output, the main producers are Brazil, the United States, Japan, Italy, Spain, Mexico, India, Israel, Argentina, Egypt, Turkey, China, Morocco and Greece. Citrus in China is distributed between 65438+08 and 37 north latitude, including 20 provinces (regions); Economic planting areas are concentrated in Sichuan, Taiwan Province, Guangdong, Guangxi, Fujian, Zhejiang, Jiangxi, Hunan, Hubei, Guizhou and Yunnan provinces (regions). The cultivation and utilization of citrus and grapefruit are recorded in Shangshu of Gong Yu, China. Citrus seeds were found in Mawangdui tomb of Western Han Dynasty in Changsha. After the Zhou and Qin Dynasties, economic cultivation became fragmented. As for the names of citrus fruit trees, they have appeared in ancient books in China, such as "orange", "pomelo", "orange" and "orange". In the early days, it was often used with "pomelo", generally referring to citrus fruit trees. "Orange" and "orange" appeared together in the local customs annals of the 3rd century. Since then, with the development of cultivation and in-depth observation, people have become more and more aware of the differences in characters between different varieties, and put various adjectives before the names of oranges, pomelo, oranges and oranges, such as "Zhugan" and "Milk Orange" found in herbs (8th century AD). The book also distinguishes oranges from oranges. Grapefruit is recorded separately. In the Southern Song Dynasty, Han Yanzhi wrote The Record of Oranges, which listed as many as 27 citrus varieties, and was the first complete monograph on citrus in the world. In foreign countries, citrus fruit trees were introduced to Europe and America late from their origin. Citron was first known to westerners. In about 330 BC, Citron spread to the Mediterranean coast through Iran. Subsequently, lemon was introduced into the Mediterranean region of Europe from 1 1 to 12 century. Sweet orange was introduced to Europe from southern China by Portuguese in the early15th century, then brought to Haiti by Columbus in 1493, and then spread to the West Indies. 65438+ was introduced to Mexico and the United States in the early and middle 4th century, and gradually became the main citrus fruit tree cultivated in the United States. Citrus was introduced to the west late,/kloc-0 was introduced to Britain from China in 805, and/kloc-0 was introduced to kumquat from China in 846. However, citrus fruit trees developed rapidly after being introduced into Europe and America. At the end of 19, the global annual output of citrus was less than 1 10,000 tons, and the average annual output increased from 1945 to11280,000 tons in/949. Among them, sweet oranges account for the largest proportion. There is only one main species, namely, orange, also known as citrus. Deciduous shrubs or small trees have small fruits, rich in gum, sour and bitter, and are inedible. After drying, it is called medicinal Fructus Aurantii. Mainly used as rootstocks, or hedges and ornamental trees. China is distributed in Shandong, Henan, Shaanxi and Gansu in the north and Hainan Island in the south. Countries all over the world are also widely introduced and utilized. Another hybrid with sweet orange, commonly known as orange, is also an important citrus rootstock. Kumquat is an evergreen shrub or small tree. There are 4 species in this genus: ① Kumquat. There are also famous golden beans and kumquat. Wild plants are found in mountainous areas such as Guangdong, Guangxi, Fujian, Zhejiang, Hunan and Jiangxi. Fruits like soybeans are round or oblate, with few juice cells and sour and bitter taste, which is unbearable to eat raw. ② Pearl jujube. Also known as jujube, milk kumquat, jujube orange and so on. Cultivated in all producing areas of China, the fruit is oblong or obovate, with sweet skin and sour pulp, which can be eaten raw or pickled, and can also be viewed. 3 kumquat. Also known as kumquat, it is cultivated all over the Yangtze River basin. The fruit is as small, round and loose as a cherry, and the whole fruit can be eaten or made into candied fruit. Trees are available for viewing. ④ Spend more money on Lysimachia christinae. Cultivated in the eastern coast of Guangdong and Hainan Province. Leaves are long and lanceolate, with wings, fruit is spherical, skin is thin, and there are many large oil cells. There are two other hybrids in this genus: ① golden bullet. Also known as kumquat. China's Zhejiang, Guangxi, Jiangxi, Hunan, Fujian, Guangdong and other provinces (regions) are relatively concentrated in cultivation, which is one of the varieties with the highest economic value in kumquat. The fruit is oval or nearly spherical, with sweet skin and meat, which can be eaten raw and has a strong candied flavor. It is generally considered to be a hybrid of kumquat and Luofu. ② Yue Yue Orange. Also known as Four Seasons Orange and Longevity Orange. The fruit is sour and fragrant, it can blossom and bear fruit every month, and the size coexists, hence the name. More ornamental cultivation. Citrus potted citrus evergreen trees or shrubs. Citrus fruit trees are the most important genus, with a wide variety and complex varieties. Scholars in different countries have different views on classification. In 1960, China scholar Zeng Mian put forward the opinions of 32 major species. In fact, there are about 10 species with important economic status, such as citron (Citrus medica), lemon (C.limon), lemon (C.aurantifolia), lime (C.aurantium), sweet orange (C.sinensis) (see orange) and pomelo (C. Do you have any rootstocks, such as bitter orange, lime and red? Lemon, red orange, doghead orange, sweet orange, sour pomelo (as pomelo anvil), etc. When building a garden on the hillside and hilly land, it is necessary to build soil and water conservation facilities such as terraces, deepen the tillage layer and apply organic fertilizer to improve the garden soil. It is best to sow seedlings in spring and autumn, and transplanting with clods is beneficial to survival. Young orchards should be watered and fertilized frequently. Adopt short stem and natural round head shape for plastic surgery. Intercropping green manure and deep ploughing can increase the content of soil organic matter, improve the soil structure of citrus, and help to store water and conserve moisture. Results Pre-flowering fertilizer, fruit stabilizing fertilizer, strong fruit fertilizer and pre-harvest fertilizer are the most important fertilizers for trees. In addition to nitrogen, phosphorus and potassium, it is necessary to increase the lack of trace element fertilizers according to soil analysis. Results The pruning of trees should be light and combined with thinning (see fruit tree pruning). The relationship between vegetative growth and fruiting can also be adjusted by smearing buds (erasing unnecessary summer buds) and releasing buds (promoting hair growth and retaining needed autumn buds). The fruit picking time is determined according to maturity and use. Diseases, insects, mites and scale insects are common pests with great influence. Canker disease is the main quarantine object and widely distributed. Huanglongbing is a devastating disease in southern China. In order to prevent and control pests and diseases, it is necessary to strictly implement the plant quarantine system, cultivate disease-free seedlings, implement isolated planting and eliminate disease vectors. In addition, freezing damage often poses a serious threat to the middle and lower reaches of the Yangtze River in China. In addition to choosing suitable environmental conditions and varieties with strong cold resistance, various anti-freezing measures can also reduce the losses caused by periodic frost in garden construction.