Characteristics and cultivation techniques of Xanthoceras sorbifolia

Characteristics and cultivation techniques of Xanthoceras sorbifolia

Artemisia mandshurica, also known as cliff papaya, Wenguo fruit, Wendeng fruit, Mengming monk Dengmaodao, belongs to the disease-free family in the plant classification, belongs to the only species, is a unique woody oil tree species in the north of China. Under the condition of good site condition and sufficient soil water and fertilizer, the tree generally grows into a tree with a height of 7 to 10 m; the place with poor site condition and barren soil is generally small tree; the site condition is especially poor, or the trunk dies or is damaged, it grows into clumps of shrubs. The cultivation of Xanthoceras sorbifolia is relatively easy, which can be cultivated into seedlings and afforestation by direct seeding. In order to alleviate the shortage of provenances and maintain the good character of a single plant, root cutting and grafting can also be used to cultivate seedlings. According to the experimental investigation data of the scientific and technological personnel of Laiwu Forestry and Urban and Rural Greening Bureau in Laiwu area in recent years, Xanthoceras sorbifolia has the characteristics of early fruit and long life, and it began to bear fruit in the second year of planting. The yield of 5-year-old plant was 5 kg, and that of 10-year-old plant was 8 kg. After that, the seed yield increased year by year with the increase of tree age. The performance in Laiwu area is summarized as follows.

1 morphological and biological characteristics of Xanthoceras sorbifolia L.

1.1 Bark

Old bark grayish brown and black-gray, flaky dehiscent.

1.2 branches

Branchlets tomentose. The old branches are grayish brown, the new shoots are brown-purple, some of them are gray-green and gray short villi, and most of the new branches are divided into two or three branches, and there are also four or five branches, the branches are stout and erect, and young plants can shoot three times a year in spring, summer and autumn under good conditions of water and fertilizer.

1.3 Bud

The new buds were formed in the previous year, ovoid, purplish brown, surrounded by most bud scales, most of which were white tomentose. Flower buds terminal or lateral, larger; leaf buds lateral, smaller, apical more acute, and mixed buds. Most of the terminal buds are flower buds, while the lateral buds are usually mixed buds in the upper part and leaf buds in the lower part. Laiwu area sprouted in early April.

1.4 leaves

Leaves are odd-pinnately compound, alternate, 20-25 cm long. Leaflets 9-19, sessile, many opposite, long elliptic to sloping needle-shaped, 2-6 cm long, margin sharply serrated, leaves dark green, generally smooth glabrous, individual leaves abaxially silvery gray tomentose. Xanthoceras sorbifolia leaves first and then flowers or flowers and leaves bloom at the same time.

1.5 flowers

The raceme is generally 15-25 cm long and the longest is 30 cm. The pedicel is slender and erect, the flower yellow-white gradually changes to lavender, and a few bases are reddish purple. It can be divided into two kinds: pregnant flower and sterile flower, the length of pistil is 6-7 mm, the stigma of pistil is trifid, 8 stamens protrude from the base of ovary, the length of stamen is only half of the ovary, the anther does not dehisce and does not disperse powder, the ovary is globular and enlarged, the development is normal, and can bear fruit. Most of the pregnant flowers are born in the middle and upper part of the terminal inflorescence, and a few in the lateral inflorescences. The sterile flower pistil is underdeveloped, the ovary is atrophied, the stamen is 6.5 ~ 8.0 mm long, the development is strong, the pollen sac breaks early, and plays the role of male flower. Sterile flowers often occur in the lower part of the terminal inflorescence and on lateral inflorescences. The flowers began to bloom in late April and Xie in late May. The flowering period was as long as 4 weeks. Generally, the lateral inflorescence bloomed 1-2 days earlier than the terminal inflorescence.

1.6 Fruit

It is a dorsal dehiscent capsule, caused by different types, such as round, conical, spindle-shaped, Obovate, green or dark green, mostly composed of three carpels, and a few composed of two to five carpels, with thick walls. The fruit varies in size, with a diameter of 4 cm and a length of 10 cm. The average weight of a single fruit is 20 × 45 g, and a few of them weigh 50 × 60 g. Each fruit has 24 seeds, and each fruit has more than 30 seeds. When the fruit is ripe, the pericarp changes from green to yellowish green, the epidermis changes from smooth to rough, the pericarp is thick and corky. The mature period is from August to September.

1.7 seed

Oblate-round or spherical, with a diameter of 1-1.6 cm. When the seeds are not mature, the seeds are white and gradually become pink and reddish brown. The mature seeds are dark brown or black and shiny. After air-drying, the seeds are dark brown and dark brown, and the luster disappears. Navel protuberant, white. The average 1000-seed weight is 400-1.175 g.

1.8 kernels

There is a brown envelope on the outside. After removing the film, the seed kernel is milky white, accounting for about half of the seed weight, heteromorphic dicotyledons. When the seeds germinate, the cotyledons remain in the seed coat and remain in the soil layer together.

2 Seedling raising technique of Xanthoceras sorbifolia

2.1 sowing and raising seedlings

The plants with strong tree potential, high yield and high seed oil content were selected as the seed mother tree. In August and September, when the pericarp changes from green to yellowish brown and the seeds from reddish brown to black, it can be harvested. When sowing with picking, the seeds do not need to be treated; if they are sown in spring next year, they should be germinated before sowing. The methods of accelerating germination include burying seeds with mixed sand and soaking seeds in warm water. Sow seeds when 2/3 split mouth is white, or select split mouth seeds one after another, sow and raise seedlings by stages. The sowing rate is 3040 kg per mu, the seedling spacing is 10 cm after the seedling is fixed, the height of one-year-old seedling can reach 60 cm, and the seedling yield is 15000 ~ 20 000 plants per mu. The 2-year-old seedlings can be afforestation out of the nursery.

Table 1 results of different treatments of cutting seedlings

2.2 Cuttage seedling

2.2.1 the survival rates of root cuttings, hardwood cuttings and softwood cuttings with different materials are shown in Table 1. It can be seen from the table that the propagation speed of root cuttings is fast, and the survival rate is more than 93.6%, which is higher than that of hardwood cuttings and tender wood cuttings.

2.2.2 the seedling raising technique of root insertion technique should select the land with high topography and leeward to the sun, and dig the sunny border, 1.2 m wide and 0.5 m deep. The soil substrate was divided into layers of soil and sand, the bottom of the sunny border was covered with a layer of clean river sand with a thickness of 5 cm, and then covered with soil with a thickness of 5 cm. The survival rate of peat soil and vermiculite was higher. Strong young trees or robust 1-year-old and 2-year-old seedlings were selected as the mother plant to dig roots 0.5 m away from the trunk. The root is picked in autumn, but it can be cut in autumn or in spring next year, and the root cutting in autumn is generally carried out in the middle and last ten days of November. The roots and ears of cuttings in spring should be treated with overwintering sand. The root ear has a short truncated length of 10 cm and a large head thickness of 0.5 cm, with a flat mouth at the upper end and an oblique mouth at the lower end, which is beneficial to cutting. When cutting short, the cut is smooth and cannot be split. Hormone treatment before insertion can greatly improve the survival rate of cuttings. The results showed that the root base was treated with 250 mg/L NAA or 250 mg/L ABT for 30 s before cutting, and the rooting rate was more than 93.6%. The cutting was carried out according to the row spacing of 5 cm × 15 cm. In order to prevent the cuttings from rotting before rooting, 0.05% methyl topiramate solution could be used to irrigate the cutting ditch. When cutting, it is better to cut directly, the cutting depth is flat with the ground, and the upper cut is covered with a small pile of live soil. According to the determination, the soil water content suitable for cuttings to take root is 60% to 80%. After root insertion, the sunny bed can be sprayed with water and covered with plastic film according to the dosage of 15: 20 kg/m 2, and sprayed with small water for 1 or 2 times during overwintering to maintain proper water content until March of the following spring. In the first ten days of March, the frequency of spraying water should be increased, spraying water once every 7 to 10 days, and when the seedlings reached more than 15 cm in the first ten days of April without capping, it indicated that the root system had been formed, and the thin film seedlings could be opened. At this time, the times of water spraying should be increased 1 / 2 times per day, and rain protection should be provided in the seedling stage. After entering the transplantation stage, the seedlings were sprayed with water half a day before the transplantation so that the seedlings could get out of the bed with soil. The seedlings can be transplanted when the stems and leaves become old and healthy after 7 days, and the best time is in the first ten days of April, which can last until the first ten days of May, but it is best to transplant on a cloudy day or after 16:00 every day. When the seedling height is about 20 cm, one new shoot with vigorous growth and the strongest growth is left, and the rest are wiped out to promote the growth of retained new shoots, and other management measures are the same as seedling cultivation.

3 planting techniques of Xanthoceras sorbifolia

3.1 reasonable close planting

The cultivation of Xanthoceras sorbifolia takes different cultivation measures for different purposes. As a soil and water conservation forest, the main purpose is to close the surface, so we should adopt high-density cultivation and plant according to the row spacing of 1 m × 1.5 m; as a field ridge protective forest, it can strengthen the ridge, prevent collapse and reduce soil erosion. Planting according to the row spacing of 2 m × 2 m, and can obtain a certain economic yield. Proper close planting can increase the early yield and improve the benefit. Specific close planting should be determined according to site conditions. The land with fertile soil and irrigation condition should be sparse, while the land with barren soil and without irrigation condition should be denser. Under the condition of dry land, it can be planted according to the row spacing of 2 m × 2 m, about 170 plants per mu, and 110 plants per mu according to the design of 3 m × 2 m row spacing. The plots with irrigation conditions can be designed according to the row spacing of 3 m × 3 m, planting 7080 plants per mu.

3.2 timely planting

Xanthoceras sorbifolia can be planted either in autumn or in spring. In Laiwu area, autumn defoliation (mid-late October) is the best, especially in the mountains and hills with large area development and no watering conditions. The survival rate of autumn planting can be as high as 90% without watering. Early planting in spring is also the key technology to improve the survival rate, and the soil can be planted when the thawing depth reaches 30 cm. The survival rate of Xanthoceras sorbifolia is extremely high, 37% higher than poplar, 18.5% higher than Robinia pseudoacacia and 49% higher than mountain apricot (see Table 2). The survival rate of planting in spring without rain for two consecutive months reached 86%, the highest of all tree species.

Table 2 comparison of planting survival of different tree species under the same site conditions

3.3 plastic pruning

The young trees should be dried in time after planting, the dry height is about 40 cm, and the fertile land and irrigated land should be higher. Adventitious stem with seedling height less than 40 cm. Summer plastic surgery was carried out in the middle of June of that year, leaving 3-4 main branches, one central trunk, the other branches short and 5-10 cm high-yield piles. At the beginning of July of that year, the root tillers were found and the sprouting tillers under the selected main branches were cut off in time, so that nutrients could be concentrated to supply the selected branches and promote their growth. The main branches left should be evenly distributed, opened at an angle and scattered with each other. In the winter of that year, plastic surgery and pruning is only used as an auxiliary means, not re-cutting. As long as the height of the selected main branch is the same, it should be released to promote its growth, and if there are too strong branches, it should be retracted properly to make its height basically the same as that of other main branches. The short branches in summer pruning are specially reserved for early hanging fruit and should continue to be thrown to promote growth and development and strive to blossom early. The apical bud blooming and fruiting tree species, which can not be cut off in pruning, is the most basic essential. no matter small or big trees, the terminal buds that should be left must be left. The task of pruning in the second year is to cultivate branch groups, adjust tree shape and promote flowering. Summer clipping usually begins in mid-June. The central cadres should be liberalized so that they can fully grow upward. The main branch can generally be removed from the heart to promote the growth of lateral branches. The rest of the branches were generally not treated to promote flower buds. If the branch is too dense, it can be cut off moderately to avoid competition. During the second summer shearing in the middle of July, it was found that there were upper dorsal branches and erect branches on the main branches, which were generally cut off. The rest of the branches should not start too much to promote their development. For three-year-old trees, the task at this time is to control horizontal growth, prevent canopy closure, retain two-layer main branches, develop excellent tree shape, and increase yield as soon as possible. The distance between the main branches of the second layer and the first layer was about 40 cm, and 2-3 were selected. The branches on the central stem of the interlayer can be retracted by half and cultured into a fruiting branch group, which will be retracted and thinned when it is too closed. The first layer of main branches should continue to take the lead and promote branching. The closure of canopy should be moderately thinned or retracted. Future pruning should be based on the principle of "shaping according to trees to promote high yield". Trees after four or five years old can form a large number of flower buds every year and blossom in spring, but the drop of flowers and fruits is very serious. At this time, the flower buds should be appropriately cut off to concentrate nutrients and improve the fruit setting rate.

3.4 spraying growth regulators

The flower and fruit drop of Wenguan fruit is serious, which is called "a thousand flowers and one fruit". The key to prevent fruit drop is to strengthen management, apply sufficient base fertilizer, topdressing in time, control diseases, pests and rodents, and strengthen the tree potential. Spraying 50 mg/L of sodium naphthalene acetate plus 0.3% 0.5% urea at full bloom can effectively increase the fruit setting rate. Increasing the rate of fruit setting is an important means to increase income. Solving the problem of falling flowers and fruits has an obvious effect on increasing fruit setting rate and increasing yield. According to the experiment, the fruit setting rate can be increased by 10.2 times.

3.5 timely harvest

As a fresh fruit, it can be harvested and sold when the contents in the kernels become turbid and have become semi-milky, and the kernels begin to be astringent and can no longer be picked. As an oil, it is necessary to wait for the pericarp to turn yellow, the seed coat to turn black and the seeds to be fully mature and harvested. After harvest, it will crack in the sun and store it for sale when the moisture content is reduced by less than 13%. Drying seeds should be carried out on the land or mat, not on the cement floor or slate, so as not to affect the vitality of the seeds.