Seed collection, budding and seedling raising techniques of Picea koraiensis

Red skin spruce (PiceakoraiensisNakai), alias red skin smelly and white pine, is an important timber forest tree species and landscaping tree species in China. It is mainly distributed in Xiaoxing'an Mountains, Zhang Guangcai Mountains and Changbai Mountains, and a small amount is also distributed along the river valleys in the east and north of Daxing'an Mountains.

1 biological characteristics and economic value

Picea koraiensis is a large evergreen tree with dense branches and leaves, strong shade and cold tolerance, and slightly tolerance to salt, alkali and drought. It is a shallow-rooted tree species, which is easy to be blown down by the wind and has high requirements for soil quality. Red spruce with straight stem and good material is an important material for construction, vehicle, aviation and papermaking. Because of its beautiful appearance and slow growth in childhood, it is often used as an important tree species for landscaping and bonsai planting in recent years.

2 cultivation techniques

2.1 the florescence of Picea koraiensis is in late May, but the cone development time is short, generally maturing in late September, and the color of the cone changes from initial green or purplish red to yellowish green or brown at maturity. As soon as the cones of Picea koraiensis are ripe, it is necessary to collect seeds immediately, otherwise the seed scales will crack and the seeds will be scattered, which will be difficult to collect. The main method of seed collection of Picea koraiensis is artificial seed collection or high branch cutting. Red-bark spruce trees are tall, so attention should be paid to personal safety and branch protection when collecting seeds. If you use high branch shears to collect seeds, you should pay attention to the protection of the branches of the mother tree, cut only the cones as far as possible, take fewer branches, and pay attention to it before the cones are cracked; if the cones have partially cracked and the seeds are scattered when the cones fall, they need to be covered with cloth, plastic film and so on.

2.2 after picking the cones of seed threshing red spruce, they can be exposed to sun and threshing. In general, after 7-8 days of exposure, the scales split and the seeds protruded. In case of overcast and rainy days, you can use fire Kang treatment, Kang surface temperature can be maintained at 25: 30 ℃, and pay attention to turn, so as not to bake the seeds. Remove the wings after the seeds come off. The wings of red spruce are easy to remove and can be screened or selected by wind. After removing the wings, dry and clean seeds should be carried out, and then stored in a ventilated, dry and cool seed storage room or sealed container to survive the winter.

2.3 the seeds of Picea koraiensis treated by accelerating germination are small and the germination rate is high, which can reach about 80%. However, in order to make the seeds germinate quickly and neatly, it is necessary to carry out germination treatment before sowing. There are three main methods of accelerating germination: snow storage, seed soaking in warm water and mixed sand stratification.

2.3.1 before freezing the sprouting soil in snow storage, select the shade and the lower groundwater level, dig the storage ditch first, the width and depth of the ditch are 1m, and the length depends on the number of seeds. After the soil is frozen and snowed, the snow is covered with 10~15cm at the bottom of the ditch, and then the species and snow are mixed into the ditch with the proportion of 1 ∶ 3, covered with snow, soil, and covered with straw. Five to seven days before sowing in the spring of the second year, the seeds were taken out and sprouted by mixing sand.

2.3.2 five days before sowing, soak the seeds in warm water for about 40 ℃ for 1 day and 2 nights, and stir them 3 times a day for 4 times a day in order to dissipate heat in time. Then take it out to dry, the drying temperature should not be too high, control it at about 25 ℃, and then sow seeds after 2-3 days. For Picea koraiensis, seed soaking in warm water is a fast and efficient method to accelerate germination. If used properly, the germination rate can be as high as 95%.

2.3.3 mix sand to accelerate germination to control the humidity of sand, then mix wet sand and seeds at the ratio of 3 ∶ 1, then pile them indoors or in the shade, adjust the stack temperature to 5: 8 ℃, pay attention to turn the pile once or twice a day, dissipate heat in time and pay attention to moisturizing. When the seed has 30%-50% split mouth, it can be sown.

2.4 the seed size of Picea koraiensis is small, so it has higher requirements for soil and soil preparation. When raising seedlings, select sandy loam with good drainage, rich nutrition, deep soil layer and loose soil, and require meticulous soil preparation, high bed and flat bed operation (low bed effect is not good) also need to carry out soil disinfection. Picea koraiensis is mainly used to sow seedlings, which can be sowed when the soil temperature at the underground 5cm reaches 8 ℃. The natural mortality rate of Picea koraiensis seedlings is high, so it can be sown densely and the seed amount per mu is 7.5~9kg. You can use strip sowing, covering the soil around 0.4cm after sowing, and gently suppressing and covering grass. Generally, the seedlings can come out within half a month, and the cover grass can be removed after the seedlings. The resistance of Picea koraiensis seedlings is weak, so shading should be carried out after weeding to avoid sunburn, and attention should be paid to timely irrigation, ploughing, weeding, fertilization and pest control. The cold prevention and overwintering of Picea koraiensis seedlings in the first year is a key measure to enhance the preservation rate of seedlings, mainly by covering soil to prevent cold or filling frozen water. Soil mulching is usually carried out before soil freezing in early winter. It should be noted that the thickness of soil cover should be higher than that of seedlings 4~5cm in order to achieve the effect of cold protection, and should be removed in time after the dry wind in the spring of the second year. Anyway. The seedling raising technology of Picea koraiensis is not difficult, as long as we master these key points, it is easy to succeed and obtain higher economic benefits.