(tree of heaven ailanthus)

(Niu Chunshan)

Scientific name: Ailanthus altissima (Mill.) Swingle. named stinky tsubaki because of the bad smell of the flowers. Also known as Tsubaki tree, evil wood, wood huller tree. Bitterwood family, stinking toon genus (the genus of about 10 species, distributed in Asia and Oceania. China 5 species, produced in the southwest, south, southeast, central and north). The ancient name for the tree was "simaroubouba", "Shuowen Jiezi": "simaroubouba wood, from wood from simaroubouba." The word "simaroubaceae" was first used in the Book of Songs, and there is a record of the utilization of "picking tea and fueling simaroubaceae, and eating my farmers". In the Tang Dynasty, there was a record of cultivation in the Tang Materia Medica in the fourth year of Xianqing (659) of the Tang Dynasty.

Morphology and use

Deciduous tree, up to 30 meters high, diameter at breast height of more than 1 meter. The bark is gray-white to gray-black, slightly smooth or shallowly cracked. Branchlets are stout, hairy at first, then glabrescent. Leaves odd-pinnate, alternate, up to 1 m or more, 13 to 25 pairs of leaflets, lanceolate or ovate-lanceolate, 4 to 15 cm long, apex acuminate, base cuneate, truncate or rounded, slightly oblique, upper entire, 1 to 4 pairs of coarse serrations near the base, tooth apex glandular dots, foul-smelling, abaxially powdered with white powder, glabrous or with hairs on the midrib. Flowers polygamous or unisexual heterozygous or homozygous, panicles terminal. Samaras, flattened, fusiform, 3-5 cm long, 8-12 mm wide; seed 1, located in middle of samara. Flowering May to July, fruit ripening September to October.

The stinky toon grows fast, adaptable, easy to reproduce, beautiful tree posture, soot resistance, saline and alkali resistance, few pests and diseases, is the "four sides" and urban industrial and mining greening and barren mountains, saline and alkaline land afforestation of important tree species. The material hardness is moderate, elastic, easy to anti-curl, not corrosion-resistant, can be used for construction, plywood, furniture, paper and rayon and other timber. Leaves can be fed to Tsubaki silkworms and castor silkworms. Seeds can be extracted oil, oil content of 34.5-56%, dry oil, saponification value of 186.7-188, iodine value of 122.2-133, acid value of 18.2. flowers can be extracted aromatic oil. Fruits and leaves are pounded, and 3 kilograms of water per kilogram can be added to control aphids. Root bark, skin, stems and seeds are used medicinally, bitter taste, can cure postpartum intestinal dislodgement and women's hematochezia, etc.; can also be used externally in decoction to wash the skin parasitic ringworm sores, sterilization and insecticidal benefits.

Geographical distribution and biological characteristics

Horizontal distribution of 22 ° ~ 43 ° north latitude, north to Liaoning, Hebei, south to Jiangxi, Fujian, east from the seashore, west to Qinghai. Among them, it is most distributed in the Loess Plateau of Northwest China and North China. The vertical distribution gradually rises from east to west, with Hebei below 1000 meters above sea level, Shanxi below 1500 meters, and to Gansu below 1800 meters.

Strongly masculine tree species, light-loving. The root system is deep, and the main root is obvious, mostly distributed below 1 meter. Lateral roots are very few and stout, mostly distributed in the soil layer of 15-60 centimeters; sometimes the main root is not obvious, and there are often several large lateral roots deep in the soil, nearly vertical.

The climatic conditions in the distribution area are: average annual temperature of 7 to 19 ℃, annual precipitation of 400 to 2000 mm, the absolute maximum temperature of 32.2 to 47.8 ℃, the absolute minimum temperature of -8 to -32 ℃. Especially the average annual temperature of 12 ~ 15 ℃, annual precipitation of 550 ~ 1200 mm is the most suitable. The adaptability of the soil is also very strong, in addition to salty soil, whether acidic soil or calcareous soil can grow, but in heavy clay or waterlogged areas of poor growth; the most suitable soil for neutral or calcareous and deep loam or sandy loam. More salt-tolerant, in the salt content of 0.4 to 0.6% of the soil can survive, 0.2 to 0.3% of the soil is well grown. Tolerant of drought and slightly alkaline. Strong resistance to soot, hydrogen fluoride and sulfur dioxide. Sparse crown, rich in rootstocks, strong sprouting. Growth rate is medium, under the condition of deep soil and timely management, the average annual tree height growth is 0.7 meters and the diameter at breast height is about 1.1 centimeters. Tree height growth is the fastest in the first 10 years, weakening after 20 years; diameter at breast height also grows faster in about 10 years. Longer life, up to 200 years or more.

Technology of afforestation

①Species collection: the seed collection period should be in September to October, or as late as November. Choose 20 ~ 30 years old mother tree harvesting fruit spike, sun dry, net seed, dry storage over winter. Dry fins weighing 25 to 32 grams per thousand grains, although the germination force can be maintained for two years, but to the second year is sharply weakened. Stinking toon germination of the appropriate season for the spring, in the temperature 9 ~ 15 ℃ when the germination rate is the highest, the average germination rate of 77% or so. Autumn and winter can also be sown, but not immediately germinate, until the following year in March to April, only the next germination. Germination rate of 48-80%. Seedlings are quite sensitive to late frost, should be appropriate delay in the sowing time. ② Seedling: bed type or field type: bed type in the Yellow River Basin should be used in a low bed. General use of strip sowing method, row spacing 40 cm, ditch depth of 3 cm, sowing width of 4 ~ 5 cm, 60 ~ 70 seeds per meter ditch, mulch 1.0 ~ 1.5 cm, light compression. Seedling height 3 ~ 4 cm for inter-seeding, plant spacing 5 ~ 7 cm. When the seedlings are 8 to 10 cm tall, they are spaced 20 cm apart, and it is advisable to apply fertilizer twice between May and July. If you use ammonium sulfate or calcium superphosphate, each time about 100 to 150 kg per hectare. Field type seeding method is slightly the same as the bed type. ③ afforestation: commonly used seeding or afforestation methods. Afforestation is appropriate in spring and fall. Fall afforestation should be carried out in the trees after leaf fall, to the end of the soil before freezing. Spring planting should be carried out when the upper strong buds of the seedling are swollen and ball-shaped. Cultivation distance, such as the creation of timber forests, in the area of deep fertile soil, can be used 2 × 3 meters or 3 × 3 meters; in the stony mountains can be used 2 × 2 meters. Planting should be deep, in dry areas buried soil depth . Should exceed the root neck 15 ~ 18 centimeters, in the wet soil buried soil depth should exceed the root neck 2 ~ 3 centimeters. In arid and windy areas, cut-and-dry afforestation is often used. Afforestation should be carried out in the early spring after the soil begins to thaw. The depth of burial should be more than 15 to 18 centimeters above the root neck, and the top is level with the ground or exposed 1 centimeter. ④Pick buds and flat stubble: pick buds can make stinky toon dry high material good, its method is: in the seedlings 1 year old start, every spring before the leaves will be spread, the upper part of the branch to retain the healthy side buds 1 ~ 2, remove the rest of the side buds. Can also be retained in the upper part of the branchlets 1 strong side shoots, remove some side shoots, that is, in the upper part of the main stem to retain the first two buds, in the order of buds below the removal of 3 to 4 side shoots, and then under the side shoots retained. In order to make the seedling cadre remarkable, in the second year, 1 strong bud can be selected at the top of the tip and all side buds can be removed. From the third year to 4-5 years, every year, you can cultivate high-stem good timber. Can also be in the afforestation after 1 ~ 2 years, every fall or spring flat stubble 1 time to promote the development of the root system, in April to May of that year to select and retain a strong sprout to promote growth.

The main pests and diseases are powdery mildew, anthracnose disease, brown spot disease, stinky toon skin moth, stinky toon ditch orbital weevil and so on.