Sowing and Seedling raising techniques of Picea crassifolia

Qinghai spruce, Pinaceae spruce, evergreen tall trees. 1-year-old shoots light green-yellow at first and pink-yellow or pink-brown at later stage, more or less hairy; leaves quadrangular, slightly curved or straight, 1.2-3.5 cm long and 2-3 mm wide, apex obtuse, or with obtuse tip, cross section tetrahedral, with stomatal lines on all sides; flowers unisexual, monoecious. Cones conical, cylindrical or oblong-cylindrical, pendulous, 7-11 cm long, 2-3.5 cm in diameter, seeds about 3.5 mm long, forsythia about 1.3 cm long, young fruit purplish red. The flowering period is from April to May and the cones mature from September to October.

Qinghai spruce is the main forest regeneration tree species and barren mountain afforestation tree species in Qilian Mountain forest region, which plays a very strong role in water conservation and soil and water conservation. Because of its evergreen seasons, conical crown and beautiful crown, it is widely used in urban greening, garden planting, beautification of well-off village and highway greening and so on.

I. seed collection and modulation

In the natural forest area of Qilian Mountain, the seeds of Qinghai spruce matured 7-10 days before White Dew. The mother tree had better choose the 30-50-year-old plant with strong growth, good stem shape and no diseases and insect pests. After harvesting, the cones should be immediately dispersed and dried in the seed farm and turned several times a day until the scales are loose and the seeds fall off and shake off the seeds with an iron hairpin. After being selected by the wind, the sundries are removed, the pure seeds are dried and placed in a cool and dry storage room.

Second, nursery site selection

The nursery should be located in sandy land and light clay loam with flat terrain, convenient water source, high soil texture and light clay loam. it is taboo to set up nursery in cold current gathering, stagnant water depression, harmful tuyere and so on.

III. Soil treatment

Select a good nursery, in the autumn of last year, use four-wheel drag to turn the new tree to a depth of 30 centimeters, and pick up the grass roots and stones. Combined with soil preparation, 20 kg of ferrous sulfate, 3911 kg of ferrous sulfate and 1.5kg of methyl isothiophos were applied for soil treatment.

Fourth, prepare the land to make the bed

The seedbed adopts a flat bed with a width of 2.5 meters, a length of 20 meters, a ridge width of 30 centimeters and a height of 30 centimeters, which requires a flat bed. 5000 kg of rotten sheep dung and 60 kg of phosphate fertilizer were applied every 667m2. The bed was turned 30 cm deep after being evenly applied. After the bed was made, it was fully irrigated. When the tools were not touched, the ploughing was meticulous and shallow, so that the bed was flat and the soil was loose and broken.

5. Seed treatment and sowing

The seeds sprouted. Generally, the seeds were treated with accelerating germination 10-15 days before sowing, soaked in 30-40 ℃ warm water for 2 days and 2 nights, selected with water, removed blighted seeds and other sundries, soaked the seeds with 0.5% copper sulfate solution for 30 minutes, washed several times, then mixed with sand to accelerate germination, stirred several times a day, and sowed after about 30% of the seeds were exposed.

Sow seeds. Spring sowing is the main method, and it is suitable from late April to early May. Using strip sowing method, according to sowing width 15 cm, row spacing 10 cm, trench sowing requires smooth and uniform ditch, ditch depth 1 cm, spread the treated seeds evenly into the ditch, mix well with sterilized sifted humus soil and fine sand at 1:3, then cover. Cover the soil with a thickness of 1 cm, then properly compacted with wood to make the seeds fully close to the soil, with a sowing rate of 15 kg per 667 square meters.

VI. Seedling management and pest control

Cover. Immediately after sowing, the seedbed was covered with sterilized Achnatherum splendens, and water was sprinkled in time to maintain the suitable temperature and humidity of the seedbed. After most of the seedlings were unearthed, the mulch was removed in batches, and the shade shed was set up before the mulch was removed.

Build a shade. When most of the seedlings are unearthed, that is, piling and kidnapping, put the shading net on the shelf, take the upper shade, the shade is 1.5 meters from the ground, and its transmittance is 30% to 40%.

Frost protection. Active prevention should be carried out by smoking, irrigation or mulching according to weather changes.

Disease prevention. Qinghai spruce seedlings are easy to be infected with vertical blight, so after the seedlings are unearthed, Bordeaux solution or 0.3% ferrous sulfate solution should be sprayed every 4 days, or 1000 times of liquid dimethazone should be sprayed with 900g per mu and sprayed with clean water after irrigation to infiltrate the roots of the seedlings. After ferrous sulfate spraying, the liquid on the seedlings must be washed with clean water within 30 minutes to avoid drug damage.

Weed. One-year-old Qinghai spruce seedlings are young and delicate, and weeding is a key link. As long as weeds are found on the seedling bed, they should be pulled out in time, and the weeds should be thoroughly cleaned. At the same time, the seedlings should be protected and the roots should not be damaged.

Overwintering management. If the management is better in summer, the seedlings can be lignified in autumn. Overwintering is relatively easy, but they all need to be protected against cold in winter, that is, in mid-October, they should be covered with sterilized grass curtains. In late April of the following year, when the weeds turn green, the curtain should be opened for 4 or 5 days, and then the grass should be covered twice. The second time to remove the grass would rather be late than early to prevent the spring cold.

VII. Summary

When raising seedlings of Picea crassifolia in the forest area of Qilian Mountain, the growth density should reach more than 2000 trees per square meter in the same year. Spruce sown in that year is prone to seedling blight, so it is necessary to apply medicine to the symptoms, prevent the disease in time, and manage the seedlings carefully.