Detailed explanation of key spruce seedling cultivation techniques, easily master the seedling cultivation method

Spruce belongs to the genus Picea in the family Pinaceae. It is an evergreen tree that can reach a height of 30 m and is the main tree species in the mountain forests of our region. Spruce wood is light, soft and fine-textured, and can be used for construction, furniture, papermaking and other timber, and it is also an ornamental tree.

I. Cutting propagation

The cutting time should be after new shoots emerge in early spring. Cut 15 cm long cuttings and carry out cutting propagation in a plastic greenhouse. In order to raise the ground temperature, fresh horse manure can be placed under the bed to maintain a ground temperature of 25-35°C, and the humidity should preferably be around 90%. The plastic greenhouse should be tightly covered and not opened frequently, so as to avoid lowering the temperature. When cuttings are inserted, dipping them in 1000 micrograms/g indolebutyric acid and ABT rooting powder No. 1 gives a better rooting effect.

II. Seed sowing and seedling cultivation

1. Bed making

Choose the sowing site well. The terrain is required to be flat, with good drainage, and the soil should not be too alkaline or too heavy and sticky. For every 667 sq m, mix in 250 kg of sand, 5000 kg of peat, and 5000 kg of decomposed farmyard manure, spread them evenly, deep-plow to improve the soil, level the land, and use a rope line to make seedbeds or drill-sown ridges. The bed surface should be 15-20 cm above the ground, 1.1 m wide, and 10-20 m long, with a 0.4 m walking path ditch left between two beds.

2. Disinfection

The sowing site can be used only after comprehensive disinfection and insect killing.

3. Treatment

The purpose of seed treatment is to shorten the dormancy period, promote rapid germination, and achieve uniform and strong seedlings. Spruce seeds are mostly subjected to low-temperature freezing treatment to promote after-ripening and break dormancy. The low temperature requirement is 5-10°C, or they can be placed outdoors for natural freezing; a certain level of moisture and aeration should be maintained. There are many freezing treatment methods: ① After snow falls, first soak the seeds in snow water for 2-3 days, then take them out and mix them with 3 times their volume of snow for piling, which is called the mixed-snow storage method. After the spring snow melts, place them in a cool place, cover with grass, spray water to preserve moisture, and sow early when appropriate. ② Put the seeds in baskets or bags and place them in river, lake, or well water to overwinter. After the ground thaws, dry them in the sun and sow in spring; soak the seeds in water at about 40°C for 1 day, then change to clean water and soak for 3-7 days, changing the water every day, then put them in straw bags or mix with sand and place them outdoors in a cool, ventilated place to freeze naturally, or place them in a freezer, keeping the seeds in a low-temperature state. In the following spring, as the temperature rises, spray water and turn them, and sow early at the appropriate time. ③ Autumn sowing also adopts the low-temperature treatment method. It is best to exceed 100 days.

If autumn sowing is too early, the roots are likely to freeze to death; for snow-buried seeds, after the snow melts the seeds are likely to become too wet and drown. About 1 week before the sowing season, take the seeds out, mix them with wet sand, and germinate them at a room temperature of about 15°C for 4-5 days. Water when the sand dries, and turn them 1-2 times every day. When 20%-30% of the seeds have cracked open, they can be sown.

4. Sowing

Adopt the no-covering-with-soil sowing method. First make the seedbed as required, do not water the base, and use a rake to move the soil on the moist bed surface so that the bed surface forms a flat and even strip-shaped uneven surface. To facilitate sowing, before sowing mix the seed-sand mixture with an appropriate amount of dry sand and stir evenly before sowing. When sowing, sow, then immediately press with a wooden roller, cover with a curtain, and water, so that the seeds are in close contact with the soil. Before the seedlings emerge completely, water frequently to keep the bed surface moist. Generally, seedlings are seen 8 days after sowing, 80% emerge in 15-20 days, and they basically emerge completely in 20-25 days.

III. Seedling stage management

When emergence reaches more than 60%, remove the reed curtain so that the seedlings receive full light. If there is no high temperature or drought, carry out full-light seedling cultivation, so that the seedlings become sturdy, have well-developed root systems, and have strong disaster resistance. To prevent late frost damage, water before the cold air arrives to increase the soil heat capacity. If frost damage occurs, water before the sun comes out so that the seedlings form ice columns, which then gradually melt, and the frost damage can be relieved.

During the seedling growth period, follow the principle of "small amounts, many times" and water regularly and quantitatively. Especially in dry climate, do not apply "horse-running water" irrigation. For mechanical watering, use high pressure, a fine sprinkler head, and a quick valve to prevent the water flow from washing away the seedlings. After the seedlings emerge completely, loosen the soil and weed in time to prevent weeds from competing for water and nutrients and to promote seedling growth. To prevent sunscald, when the ground surface temperature reaches 36°C, water immediately to lower the temperature.

IV. Pest and disease control

Adopt the method of regulating the ecological environment and restraining the spread of pests and diseases. In addition to seed disinfection, for invasive diseases, regulate ecological factors such as water, fertilizer, air, heat, and light to solve them, prevent chemical agents from polluting the environment, and promote good seedling development with strong resistance to pests and diseases.