English name: Deodar Cedar, Indian cedar, Himalayan cedar, Himalayan cedar. Cedar is native to Afghanistan, Pakistan, northern India and Tibet, China, with an altitude of1200-3000m. Cedar was introduced from abroad in China 1920. It was first planted in Nanjing, Shanghai, Qingdao, Beijing and other cities. It has a history of more than 80 years and is cultivated almost all over the country. Cedar is suitable for Nanjing's ecological environment and people's love. So Nanjing has the largest number of plants, and the trees in Nanjing are all cedars. According to the statistics of 1982, more than 53,700 cedars are planted in the city. The first cedar planted is 20 meters high, and a cedar on the campus of Nanjing University is 30 meters high and has a bust of 2.7 meters, which is thriving. Cedar has become one of the backbone tree species for urban greening in Nanjing. At present, the main producing area of cedar in China is Nanjing, and there are 50,000 mu of cedar bases among 65,438+10,000 mu of seedlings in Nanjing. Cedar seeds are mainly produced in India and the United States. In recent years, the forestry department has introduced a large number of cedar seeds from India, which has created conditions for the large-scale promotion of cedar. Cedar is an evergreen tree of Pinaceae, with needle-like leaves, usually triangular, long branches with spiral needles and short branches with needle clusters. The stem of the tree is straight and thick, with dense branches and leaves, which extend layer by layer to form the tower crown. Wood is tough and delicate, which is a good ornamental tree species and timber tree species for landscaping. There are five kinds of Cedar, among which Himalayan Cedar, Lebanese Cedar and Atlantic Cedar are all introduced and cultivated in China, among which Himalayan Cedar is the most. According to the tree shape and branches of Cedar in Nanjing, it can be divided into three types: 1. Cedar, with thick leaves and short needles, the average length is 2.8 ~ 3. 1 cm, with spreading branches, slightly drooping or spreading branchlets, majestic crown and slow growth; 2. Cedar with drooping branches has long needles, with an average of 3.3 ~ 4.2 cm, drooping branches, verdant crowns and rapid growth; 3. Cedar with upturned branches, with needles of 3.2 ~ 3.8 cm, slightly drooping branchlets, wide crown and fastest growth. Cedar was introduced from the United States in 1920, and was first planted in Nanjing, Shanghai, Qingdao, Beijing and other cities, with a history of more than 70 years. Cedar is suitable for Nanjing's ecological environment and people's love. So Nanjing has the largest number of plants. According to the statistics of 1982, more than 53,700 cedars are planted in the city. The first batch of cedars planted is 20 meters high, and there is a plant on the campus of Nanjing University with a height of 30 meters and a bust of 270 cm, which is thriving. Cedar has become one of the backbone tree species for urban greening in Nanjing, and is widely planted in parks, streets, squares and courtyards. Beijing east road, Yudao Street, Zhongyang Road and Zhongshan South Road are the main roads, and cedar is the street tree. These roads are bright green all year round. Since the 1960s, many cedar scenic forests have been built on the hills inside and outside the city, such as Zijin Mountain, Yuhuatai and Xiaohongshan. Decorate the ancient city of the south with dignity and beauty. Cedar is a temperate tree species, but it has strong adaptability. It can be planted in warm and hot areas, and can also grow in the northern end of temperate zone and the southern end of cold zone. It can withstand short-term -25℃. It requires abundant rainfall, but it can also adapt to the annual rainfall of 500 ~ 600 mm It is sunny and not tolerant of shade. It needs fertile and loose soil and is barren, and it can also grow on the gravel ground in the mountainous areas around Nanjing. Like neutral and slightly acidic soil, it is a fast-growing tree species. 1 year-old seedlings can reach 30 cm, 2-year-old seedlings can reach 50-70 cm, and the next year can be increased by 50-80 cm. The growth of DBH is above 1 cm per year on average, which can reach 65438 0.5 cm in isolated planting, and gradually slows down after 40 years old. Cedar is mostly dioecious, and the dioecious rate is 95%. Generally, it takes about 30 years for female plants to blossom and bear fruit, and the male plants bloom several years earlier. It is difficult to pollinate cedar naturally, so artificial pollination is needed to improve the seed setting rate.
Characteristics/habits of cedar
Cedar is a long-lived evergreen tree, its origin can reach 600-700 years, the tree is 60-80 meters high and 3-4.5 meters in diameter. The trunk is tall and straight, majestic, with flat lateral branches, beautiful posture, grayish brown bark, smooth when young, and cracked into scales and peeled off in old age, which is even more ancient and vigorous. It has the reputation of "Queen of Garden Trees". The big branches of cedar rotate and spread irregularly, the branchlets are slightly pendulous, and the lower branches are close to the ground, forming a tower-shaped crown with a small top and a large bottom. Cedar leaves are needle-shaped, 2-5 cm long, blue-green or gray-green, with white powder when they are young, and young leaves are mostly white. From a distance, they look like pine branches covered with snow, so they are named cedar. There are several gray-white stomatal lines on both sides, and the cross section is triangular, clustered on short branches, sparsely alternate or spirally scattered on long branches. Cedar is dioecious, and few plants are the same. Both male and female bulbs are single-branched, the male bulbs are yellow, the female bulbs are purple at first, then turn light green, and open in June10-1. The cones are oval, large and erect, and mature in June 5438+the following year 10.
Cedar is a positive tree species, which likes sunny, moist and cool environment, deep soil layer and good drainage, and can also grow in sticky loess, barren land, stony land and exposed rocks. Acidic soil and slightly alkaline soil can adapt. It grows well in the East China Plain (PH 6-7) and can bear fruit. After artificial pollination, seeds with germination ability can be obtained. Cedar can adapt to a wide range of climate, from subtropical to southern cold regions, and grow well in areas with annual rainfall of 500-1000 mm. Cedar is very cold-tolerant, with the lowest temperature of-15.9 degrees Celsius. Generally, it will not suffer from freezing injury, but it is poorly adapted to hot and humid climate and often grows poorly. Cedar is afraid of water, and it grows badly or even dies in waterlogged depressions or places where the groundwater level is too high. Young trees can withstand a certain amount of shade, and big trees need sufficient light. Cedar is a shallow-rooted tree species with underdeveloped air roots, weak wind resistance and vulnerable to wind damage. Cedar has poor smoke resistance and is sensitive to harmful gas of sulfur dioxide, so it can be used as an atmospheric monitoring plant. If the air humidity is high during the spreading period of young leaves, young leaves are vulnerable to sulfur dioxide, and after being killed, young leaves wither rapidly, or even the whole plant dies. Cedar, Japanese golden pine, Aralia elata and Jushan (the master of the world) are collectively called the three famous trees in the world. It is also the most planted backbone tree species in urban landscaping in China. Cedar is most suitable to be planted in the center of the flower bed alone or clustered on the edge of the lawn and on both sides of the building, and it is also very stylish to plant it on both sides of the main road and square. But it is not suitable for planting near tobacco sources. Huagang, Hangzhou uses cedar to divide the fish viewing space, which is unique and has achieved good results. Cedar is excellent in material, dense in texture, not easy to warp and crack, rich in oil, strong in durability and corrosion resistance, and can be used as a good material for furniture such as buildings, bridges and railway sleepers. Oil can be extracted as a raw material for light industry. Recently, a sesquiterpene diol and its isomers were found in cedar needle oil, which can be used in medicine. The propagation methods of cedar mainly include sowing, cutting, layering and grafting. Cutting and sowing are usually used. Cedar seedlings propagated by sowing method have symmetrical branches, strong germination, good tree shape and strong stress resistance, and are cutting mother trees for cutting propagation.
Cedar variety
According to the propagation method, it is divided into cedar (also known as cutting cedar and cutting cedar) and sowing cedar (also known as cedar seedling, cedar seeding seedling, cedar seedling and seedling). Because of the rich source of cedar seeds, Nanjing mainly produces and sows cedar. According to color, it is divided into: green cedar (that is, common cedar), silver cedar and Jin Xuesong.
According to the country, it can be divided into: North African cedar, Lebanese cedar, Japanese cedar, Indian cedar and Himalayan pine. According to the growth of cedar needles, it can be divided into: thick-leaved cedar (also known as short-leaved cedar, with an average length of 2.8-3. 1 cm, with flat branches, slightly drooping or spreading branches, majestic crown and slow growth) and pendulous cedar (also known as long-leaved cedar, with an average length of 3.3-4.2 cm, drooping branches and crown). According to the shape of needles, it can be divided into straight-leaved cedar (that is, ordinary cedar) and curved-leaved cedar. Cedar with curved leaves is a variety of common Cedar, which is small in quantity and suitable for making bonsai.
According to the tree, it can be divided into arbor cedar (that is, ordinary cedar), spherical cedar (cedar ball) and bonsai cedar.
Seeding and Seedling Raising Technology of Cedar —— Cedar Propagation Technology
Cedar is afraid of waterlogging, so the nursery land should be built on sandy soil with convenient irrigation and drainage, high dry terrain, sunny, slightly acidic and deep fertile soil layer. Not raising seedlings in vegetable fields and old nurseries for many years.
When ploughing the nursery, whole cake fertilizer or decomposed animal manure should be applied as base fertilizer. If seedlings are raised in fertile fields, calcium magnesium phosphate fertilizer 100kg should be applied per mu. Before the last ploughing and harrowing, apply 2-3kg Dixon or 20-30kg ferrous sulfate per mu for soil disinfection, and then make a deep furrow and high ridge seedbed with a width of1-1.2m and a height of 0.3m. Cedar seeds are generally about 6,000-8,000 seeds/1 kg, with empty seeds. Before sowing, seeds should be soaked to accelerate germination, and the best effect is to soak seeds in cold water for 96 hours. You can also soak in warm water at 45-50℃ for 24 hours, disinfect with 0. 1% potassium permanganate for 30 minutes after soaking, then rinse with clean water and dry. Don't sow them with moisture. Sowing time is generally carried out before the vernal equinox, sooner rather than later, and drilling is better, with row spacing10-15cm and plant spacing of 4-5cm; Seeds should be planted vertically in the sowing ditch. Ensure that the big head of the seed is facing upwards, and the sowing amount per mu is 15-20kg. After sowing, cover with yellow mud or burnt mud ash with a thickness of 1-2cm. Cover it with a thin layer of straw, and then sprinkle water on it with a watering can to keep the bed moist. It can germinate in about 3-5 days, and emerge one after another in about half a month. The emergence time lasts more than 1 month, and the germination rate can reach 90% in general. In order to prevent the newly unearthed seedlings from being lost due to rain and control the temperature in the shed, ventilation should be carried out when the temperature in the shed is kept at 15-20℃; In sunny days when the outdoor temperature is above15 C, uncover the film during the day and cover it at night. When more than 70% seedlings emerge, pull out the straws in batches, set up the frame in time, and cover it with sunshade net or reed curtain for shade. During the growth of seedlings, in addition to frequent watering, loosening soil and weeding, fully cooked pancakes should be fertilized once every half month, and the concentration can be gradually increased; If chemical fertilizer is applied, it can be buried between sowing ditches, and seedlings must not be touched, otherwise seedlings may be burned. In order to prevent diseases, 1% bordeaux mixture should be sprayed every half month when the seedlings are in full bloom until the rainy season is over. After beginning of autumn, the shade shed was demolished. Cedar cutting seedling raising technology-Cedar propagation technology Cedar cutting time can be propagated all year round, and it is suitable for cutting in the middle and late March in spring, May, June in summer and mid-August in autumn, but it can still be cut in late autumn and early winter, but it can't take root in that year. In large-scale production, spring seeds and summer sowing are the main crops, with high survival rate and good economic benefits. When selecting cuttings, the annual strong branches in the middle of the crown of young mother trees should be selected. If branches of trees older than 10 are used, semi-lignified branches in the upper part of the crown should be used, and spring shoots of the current year should be used as cuttings in summer. It is best to cut in dew weather, which can be carried out in the morning or cloudy days to prevent the sun from being too strong and the branches from losing water. After cutting, align the branches with the base, wrap them with wet toilet paper or old cotton cloth for moisture retention, and then take them back to the room for treatment. Cut the cuttings into 1.5 cm length indoors, cut the base into a horse's ear shape at 0.5 cm below the bud with a sharp knife, and cut the upper part into a flat mouth at 1.5 cm above the node. Be careful not to tear the epidermis and damage the axillary buds. Cut the cuttings, separate them according to their diameters, bundle them into small bundles, then soak them in 500ppm aqueous solution of naphthylacetic acid 1 hour, take them out and dry them slightly, and don't leave them for too long. Cuttings should be kept fresh to improve the survival rate. When cutting seedbed, cuttings should be separated according to the length of diameter, the row spacing in spring is 5 cm× 9 cm, and the density in summer is appropriate. Before cutting, shallow ditches can be made on the seedbed, and then cutting can be carried out. Both straight insertion and oblique insertion are possible, but oblique insertion is better, with large contact area, which is conducive to rooting. Insertion depth is 6-8 cm, after insertion, it is compacted and fully watered.
The light transmittance is preferably 30%-40% by building a shade shed or pruning and covering it with a shade net. After insertion, spray water with a watering can or sprayer every morning and evening 1 time, and spray less in rainy days. After the cuttings take root, the amount and frequency of water spraying should be controlled to prevent the roots from rotting. At the same time, it is necessary to strengthen the management of fertilizer and water. When the temperature is high in summer, double curtains should be covered to cool down and ventilate around. Shading sheds must be covered early and uncovered late in sunny days, and ditches should be cleaned in time to prevent waterlogging in rainy days. After autumn, the shade shed can be removed for seedling hardening to improve the stress resistance. Generally, it can take root about 50 days after transplanting, and the survival rate is above 85%. Spraying 0.2% urea or potassium dihydrogen phosphate can promote the growth of new shoots. In the spring of the following year, it can be transplanted to heel in in the general garden according to the plant spacing of 30cm× 50cm.