How many years does it take to grow yew?

Taxus, also known as Taxus, is a genus of Taxus.

Taxus chinensis belongs to shallow-rooted plants, with inconspicuous main roots and developed lateral roots. It is a rare natural anticancer plant recognized as endangered in the world. It is an ancient tree species left over from Quaternary glaciers, and has a history of 2.5 million years on the earth. Due to the slow growth rate and poor regeneration ability of Taxus chinensis under natural conditions, a large-scale raw material forest base of Taxus chinensis has not been formed in the world for a long time. From 65438 to 0994, Taxus chinensis was designated as a first-class rare and endangered protected plant in China, and it was also called "national treasure" by 42 countries with Taxus chinensis in the world. The United Nations also prohibits logging, which is a veritable "plant giant panda".

cultivation techniques

breeding method

Seed propagation

Taxus mostly reproduce with seeds. 165438+ 10 seeds can be harvested when they are ripe, then the fleshy seed coat is cleaned and dried, then buried in a cool and dry place, covered with wet sand layer and covered with plastic film and grass curtain. The seeds should be turned twice a month in summer and autumn, and can be planted in early March of the following year. The seedbed should be a slightly acidic sandy loam with leeward and good drainage. The bed width is 1m, the ditch width is 40cm, and the ridge rises from east to west. Steel plates with a height of 25cm and a thickness of 4cm are buried on both sides of the ridge, and the depth is 10cm. Bed soil requires intensive cultivation, and carbofuran is applied to prevent underground pests. Vermiculite, river sand, peat and garden soil are mixed with bactericides such as carbendazim or thiophanate-methyl to form a matrix, which is filled in the steel plate and is 3-5cm higher than the middle of the side plate. Covering with plastic film, sealing and fumigating for 3-5 days to sow. Seeds are evenly spread on the bed surface, and the sowing amount is about 200 seeds per square meter. After sowing, flatten the seeds slightly with wooden boards, cover them with mixed matrix soil with a thickness of 1 ~ 2cm, and cover them with straw curtains or plastic films for heat preservation and moisture retention. When the weather is dry, spray water properly, and it will germinate and emerge after 40 days. At this time, the plastic film or straw curtain should be removed, and a 2-meter-high shade shed should be set up above the seedbed, and a sunshade net should be covered to prevent direct sunlight. Keep the seedbed moist. Build a low arch shed in rainy days and cover it with plastic film to prevent the seedbed from getting too wet. Do a good job in drainage and ventilation of seedbed, and prevent and control pests and diseases in time. Apply decomposed light cake fertilizer every 10 day at seedling stage, and avoid using chemical fertilizer and concentrated fertilizer. After one year's careful maintenance and management, the seedling height can reach 15 ~ 25 cm, with 2 ~ 3 branches. Transplantation can be carried out in early April. The planting site should be leeward, dry, slightly acidic sandy soil rich in humus, with a depth of 20 cm and 5 kg of decomposed organic fertilizer per square meter. Raise the ridge and dig a deep ditch, with the ridge width of 100 cm and the ditch width of 30 cm. There are 5 rows in each row, the row spacing is 20cm, and the plant spacing is15cm. Transplanting should be done on cloudy days, and soil balls should be planted. Immediately after transplanting, water it once, and build a 2-meter-high shade shed on it. Cover it with a shade net in sunny days and remove it in rainy days and at night. Strengthen the management of fertilizer and water during the growth period, and generally apply fertilizer and water to the decomposed cake once every 10 day. Do a good job in pest control management. In summer, it is necessary to strengthen shade and cool down, and spray water when necessary to create a cool and humid environment conducive to seedling growth. Taxus chinensis is not only the first-class material for making high-grade furniture, but also a medicinal material with great medicinal value and an excellent tree species for landscaping. With the maturity and development of its artificial propagation and cultivation technology, the application scope of Taxus will be more extensive.

When raising seedlings of Taxus chinensis seeds, it is necessary to pay attention to the preservation method of seeds, mixed sowing of sand seeds or temperature control, which has a good effect on budding after overwintering and breaking dormancy habits. Rub the seed coat before sowing, soak it in warm water and treat it with drugs and hormones. Shading after emergence is the key to raising seedlings. It can prevent the seedlings from being burned at high temperature, keep them moist and have a light transmittance of 40%. The emergence rate of Taxus cuspidata and Taxus mairei can reach 70 ~ 80%, and the emergence temperature should be higher than 65438 05 degrees.

The dynamic growth of seedlings is as follows: the plant height and stem diameter of seedlings grow slowly two years before emergence, and the plant height generally grows about 10cm in one year, and grows faster after transplanting for one year. The annual growth can reach 20 ~ 30cm in 3 ~ 5 years.

cutting

The cutting propagation of Taxus chinensis is better in spring and autumn. Generally, low shed shading treatment should be done when cutting. Generally, the survival rate of cutting can reach more than 70%. Conventional cutting is only about 3% ~ 20%. Shading rate is not less than 60%. Cutting media should be carefully rooted. At the beginning, the humidity should be kept at about 75 ~ 85% intermittently. Avoid water loss caused by strong wind.

The factors affecting the survival rate of cutting are generally: tree age, temperature, drug concentration, substrate, season, humidity, variety and other human factors.

In the process of rooting in the first year, the aboveground part of the cuttings grew slowly, but took root quickly and developed lateral roots. After transplanting in the second year, further shading treatment and seedbed management are needed. Ensure the corresponding environmental conditions and accelerate the growth. The growth rate is the fastest in summer and slower in winter and spring. Pay attention to the change of temperature at this time. Long-term drying can lead to growth inhibition or sudden death. However, after the seedlings of Taxus chinensis are strong in the seedbed, the survival rate of afforestation is very high. It rarely dies and grows rapidly.

Seedling management

temperature regulation

After mowing, the ground temperature of the bed surface should be 18℃ ~ 25℃, the temperature in the shed should be 22℃ ~ 28℃, and the soil humidity should be 60% ~ 70%.

Seedling management

Observe the temperature and humidity in the plastic greenhouse every day. When there are water drops in the plastic film of the bow shed, there is no water shortage; When there is no water drop, there is water shortage. When there is water shortage, uncover the plastic film and connect rain or water properly. When the temperature in the shed reaches 30℃, the plastic at both ends of the arched shed should be opened in time for ventilation. Seal the plastic film after sunset to keep the temperature in the shed. Before snowfall, remove the upper sunshade net and move it under the plastic of the bow shed to continue shading to prevent direct sunlight. About 45 days after cutting, the cuttings began to take root, and basically sprouted in about 65 days, and shoots of 3 ~ 5 cm could grow in that year. Transplanting can be carried out after 2 years, when the root system is developed and easy to survive. When it grows to 6-8 years, the height of the seedlings is 80-90 cm.

Weeding and disease prevention

Weeding should be done when the grass is just growing. If the grass is big and strong, it will be pulled out with the seedlings carelessly, or the seedlings will die because of air leakage, so pull out the grass early and weed frequently to avoid water and fertilizer loss. In rainy season, Taxus seedlings are prone to root rot and stem rot. At this time, 70% Dixon 400 ~ 700 times solution can be sprayed for irrigation. In dry and high temperature season, seedlings are prone to leaf blight, which can be controlled by spraying 1% bordeaux mixture. [6]

tissue culture

Tissue culture makes use of the totipotency and clonality of plant cells. The tender stems, needles, bark, cambium, aril and embryo of Taxus plants are used as plants for cultivation and research.

1. A large number of tissue-cultured seedlings can be obtained in the laboratory by selecting excellent Taxus species as explants and inoculating them in the culture medium, and through the steps of callus formation, rooting and seedling bud formation. After substrate transplanting, seedling hardening and epidemic prevention, it became a production seedling.

2. The proportion of late and early callus formation of Taxus chinensis is different among different species and different plants of the same species. At the same time, it is related to explant type, sampling place and season, lighting conditions, culture medium types and other factors.

Potted maintenance

First, try not to spray fertilizer on the leaves of the newly bought Taxus bonsai when the new buds sprout, because the Taxus bonsai has not really survived or the leaves are too tender at this time. If fertilization is applied at this time, the leaves or buds will shrink and curl. Thus affecting the normal germination of new roots, the amount of water sprayed on the leaves should not be too much, and the degree should be that the sprayed water droplets can be seen on the leaves but do not drip down. Spray it two hours before dark in the afternoon, and don't leave water droplets at night (especially when the amount is large), otherwise it will affect the normal growth of young leaves or the yellowing of leaves, and affect the healthy growth of plants. The reverse side of the leaf can be sprayed more than the front side, because there is a wax protective film on the front side of the leaf, which will hinder the absorption of nutrients and water, while there is no wax layer on the back side of the leaf, which has more pores and stronger ability to absorb water and fertilizer. So that the back surface absorbs faster and more than the blade surface). Depending on the situation and temperature, once a day or two or three times a day. Pay attention to frequent ventilation in the room. [7]

Secondly, for the newly bought Taxus bonsai, transplanting it from the planting base to the flowerpot will damage part of the root system and make the nutrient supply between the root system and the branches and leaves unbalanced. Especially those bonsai with lush foliage, the evaporation of leaves is greater than the absorption of roots, and the leaves on them are curly and dry when the basin soil is kept moist. At this time, it is best to prune the branches and leaves properly to reduce the excessive consumption of water and nutrients by the branches and leaves and restore the growth of roots as soon as possible. At the same time, we should control watering and keep the soil in the basin. At the same time, Taxus chinensis has strong germination ability, especially the growth ability of new branches, which is resistant to pruning. After survival, new branches and leaves will germinate soon. If necessary, plant rooting agent or rooting agent can be used, and the pot soil can be watered once every seven days or so, and it can be watered three or four times continuously (using good quality products and not too much water), so that the root system can grow rapidly and healthily. Restore the supply balance of roots and leaves as soon as possible, so that yew can grow well. [7]

3. As the nutrient content of potted Taxus chinensis is limited, it can only meet the growth needs for about half a year, or the current plant shape is large, which consumes a lot of nutrient content. It is recommended that consumers replace the original pot as soon as possible after purchasing. Because our company re-potted bonsai for more than a month, it was stored in the distribution company for a period of time, and yew likes fertile and loose soil. It is best to change the pot as soon as possible. When changing pots, the inner diameter of the new pot should be at least five centimeters larger. Every year in February and March, before the new buds germinate, the trees and the pot soil are poured out together under the condition that the pot soil is not dry or wet. Try not to break the original clay ball. If you find too many roots after survival, you can cut off the bad roots appropriately. Put the tree in a new flowerpot and fill it with nutrient soil. Only by closely connecting the soil and roots in the pot can you improve the survival rate, otherwise the plants will not survive and will not grow vigorously. But don't press the soil too hard. If the roots are too hard to breathe air, the roots will rot and the plants will die. Water once immediately after planting. Leave the basin in the shade for a few days. After watering, the pot soil should not be turned over, otherwise it will be easy to harden, or the soil is too solid and has poor air permeability, which will easily cause root rot. [7]

4. Fertilization method of Taxus bonsai: The three elements of plant growth are nitrogen, phosphorus and potassium fertilizer, and nitrogen fertilizer can promote the growth of flowers and branches; Phosphate fertilizer can promote the formation of flowers and fruits; Potassium fertilizer can promote the growth of stems and roots.

Because bonsai is cultivated in limited potted space and limited cultivation soil, organic matter is decomposed into inorganic salts by bacteria and absorbed by roots. With the growth and consumption of Taxus chinensis, the nutrients in potted soil are gradually lacking, resulting in insufficient growth supply. Although the prepared nutrient soil is used in bonsai, it is not suitable for fertilization within three months after purchase. As long as the potassium dihydrogen phosphate solution is poured or sprayed once every seven to ten days at night 1000 times. Control the amount of water, not too much. Only when the leaves are pale, the plants are thin, the leaves are yellow and white, the leaves are angular, the leaves are "dry-burned" and the leaves are premature, apply 1000 times of liquid urea and 800 times of potassium sulfate to remove the sediment, and then water the soil once a month or so. It is best to use fully decomposed light bean cakes (about 10%) the next day after fertilization. The above two fertilizers can be used alternately, or you can dig two small pits in each pot and put five or six urea and seven or eight high-quality compound fertilizers in it. Cover with soil and water to dissolve fertilizer. Taxus bonsai should not be fertilized with raw fertilizer or thick fertilizer. Topdressing should be based on nitrogen and phosphorus fertilizers, not too concentrated. [7]

Five, bonsai watering method: the principle is "no watering, watering thoroughly".

Water is an important part of flowers and trees. All life activities of flowers and trees must be carried out with the participation of water. No matter photosynthesis or transpiration, it is inseparable from water. Water can maintain the swelling pressure of cells and straighten the branches and leaves. However, if the limit is exceeded, the plant growth will be weak. If there is too much water in the basin soil for a long time, the leaves will turn yellow, the leaves will fall off, the roots will rot and even die.

1. Look at the surface color of the basin soil, the leaves are slightly curled, and it feels a little soft to press the basin soil with your fingers. When the sound made by tapping the middle and upper part of the basin body with your fingers is dull, you don't need to water the basin soil, just spray the leaves to replenish the water. When the surface of the soil is white, press it with your finger, and the soil will be hard, and a circle of cracks will appear between the basin and the soil. Tap the middle and upper part of the basin with your fingers, and make a crisp sound of "bang". When the new buds and leaves wither, water the basin soil. Before watering, the gap between the soil and the basin should be compacted with hard objects before watering, and then poured with a large spoon. When pouring water, the spoon should be close to the edge of the basin, and the water should be poured in at once, so that the basin soil can absorb enough water. If you pour a small amount of water into the basin for a while, you will see that water will flow out from the bottom of the basin quickly, indicating that the soil and basin are not fully compacted. The gap between the basin wall and the soil should be compacted with objects before pouring. When the structure of the basin soil is normal, it is better to water it for about 40 seconds to 1 minute, and the water slowly seeps out from the bottom of the basin. The water temperature for watering must be close to or consistent with the temperature at that time. When watering with tap water, you should put the water in the sun for about three hours before watering, because light helps to decompose oxides in tap water and raise the water temperature. You can also put the water in a big basin for half a day or pour it overnight. If there are many bonsai, it is best to put the water in a vat to make the water temperature as close as possible to the air temperature and soil temperature. Especially in the hot season, besides watering the pot soil, it is also beneficial to spray water and fog on the leaves to keep them moist. The soil in the basin can be kept slightly dry, not too wet. If the basin is too wet for a long time, check each basin according to the actual situation, and be careful not to pour too much water.

2. The leaves of Taxus chinensis are evergreen all year round, which is suitable for indoor display. However, it is not easy to put the bonsai of Taxus chinensis in the air outlet, otherwise it will increase the evaporation of water in the leaves of Taxus chinensis, which will easily lead to rapid dehydration of the branches and leaves of Taxus chinensis, resulting in curly and dry leaves. If you put it in an air-conditioned room and turn on the air conditioner every day, you should spray water on the leaves every day to keep the humidity of the leaves and put a basin of clean water indoors. If it is a room with heating in winter in the north, stay away from the radiator and put a basin of water on the radiator to increase the indoor air humidity. When the temperature exceeds 30 degrees Celsius in summer and autumn, the shading and cooling work should be strengthened, and it can be moved to a ventilated place in the north. If necessary, spray water to cool down and create a cool and humid environment for the growth of Taxus chinensis. And avoid the room where the western sun shines directly on the Taxus bonsai. In winter, the watering amount of bonsai should be controlled to avoid being too wet for a long time. Because plants don't grow vigorously in winter, there is less volatile water in leaves. If the potted soil is too wet for a long time, the surface of the potted soil will be hardened and airtight, which will easily lead to the occurrence of plant root rot. When raising yew indoors, we must pay attention to indoor ventilation.

3. The soil for planting Taxus chinensis should be loose, rich in humus, fertile and slightly acidic (pH = 5.5 ~ 7). Taxus bonsai can't pour tea. If you often pour out the remaining tea, it contains raw alkali such as theophylline. It will change the pH of the soil for a period of time, and it will also have a relatively destructive effect on the organic nutrients in the soil. It will inhibit the growth of Taxus chinensis and cause excessive soil moisture, hinder the ventilation of basin soil and cause root rot and stem rot. A week or so when conditions permit, move the bonsai of Taxus chinensis to the balcony at night to receive dew, and put it in the sun for an hour or two in the morning (before 10), which is beneficial to the growth of Taxus chinensis and improves its disease resistance. In summer and autumn, it is necessary to prevent the sun from shining directly on the yew through the window, so as to avoid high temperature burning the leaves and affecting the ornamental value. [7]

Sixth, pay attention to the main points

1, Taxus chinensis should pay attention to the adjustment of light, because the tree is small and needs light, but it cannot be placed in strong light for too long. Generally, it can be dried for about two hours before ten o'clock or after five o'clock every morning in summer and autumn. Usually receives scattered sunlight. Otherwise, the tip of the blade will be browned due to strong light burning, and indoor ventilation should be maintained to avoid unhealthy growth phenomena such as withering and sagging caused by too dry indoor air.

2. In the case of new bonsai, the tender leaves are dark yellow and dull, and the withering phenomenon at the top of the new shoots is generally caused by excessive watering, which makes some roots rot and weakens the ability to absorb water and fertilizer. If the symptoms are mild, the watering amount should be controlled, and the topsoil on the surface of the basin should be lightly loosened with a hard and blunt object to make the basin soil breathable. Moving to the place where dew can be received every night and moving to the shade at 8 am is beneficial to the healthy growth of roots. If the leaves are yellow and curly in a short time, it means that the root rot is serious. Because root rot is checked immediately, (normal fibrous roots are all white in shape), if it exceeds half, it is generally hopeless.

3. Old leaves have yellow leaves from bottom to top, but new leaves generally grow normally, generally because there is no one-time watering and the roots are short of water. Sometimes the top leaves are dry and curly, and the dry leaves will fall off as soon as they touch, but the old leaves grow normally, which is generally caused by water shortage at the roots, so it is necessary to water them once. When watering, you must first compact the cracks along the basin with objects to prevent water from leaking quickly from the cracks. The illusion of flood will cause the roots to die because of long-term water shortage. Move outdoors at night to receive more rain and dew, and receive two hours of sunshine in the morning and evening to restore the growth of yew.

4. Taxus chinensis is suitable for weak acid soil. If watered with alkaline water for a long time, the leaves will turn from green to yellow, or even fall off. Because of adding acidic nutrients or spraying leaves or potted soil with two thousandths of ferrous sulfate solution once every ten days for three times in a row. It can make leaves turn yellow and green due to alkali.

Every year in March and April, yew will sprout a lot of tender buds, which will consume a lot of nutrients. At this time, you can remove the inward growing buds to prevent the leaves from turning yellow or falling off because the branches are too dense and ventilated. For transverse branches and inner branches, thinning branches can improve ventilation and light transmission, and can save excessive consumption of water and nutrients. It is best not to spray liquid fertilizer on the leaves when the buds are just sprouting, nor to pour thick fertilizer on the roots.

6. If only urea is used as topdressing nitrogen fertilizer, the concentration is generally one thousandth; If only potassium dihydrogen phosphate is used as topdressing phosphate fertilizer, the concentration is one thousandth to two thousandths, and the topdressing interval is seven to ten days. [7]

afforestation

Selection of afforestation sites

In the middle and lower part of the hillside, the slopes of shady slopes, grass ditches and mountain bays at the foot of the slope are less than 35 degrees, the soil ph value is 4.5-7.0, the fertility is high, the water content is high, and the drainage is good, all of which can be used as afforestation sites. Artificial young forest land with canopy density not greater than 0.4 can also be used for afforestation.

Carry out soil preparation

Strip or hole soil preparation. The specification of the point is 40cmx40cmx30cm (length x width x height). Different land conditions can be combined with soil preparation and fertilization according to land fertility.

planting density

1 100/ mu. Plant spacing is 60x400cm (Hengshan x Shunshan). The planting density of artificial young forest should be determined according to the actual enclosure of young forest, and the principle is to plant it in the open space with good lighting conditions outside the crown of young forest.

Afforestation time

February-April in spring and September-165438+1October in autumn.

management control

After afforestation, it should be cultivated 2-3 times a year. Hoe twice in May-June and August-September, and strike with a knife in July. After afforestation, from the second year onwards, combined with weeding and topdressing in May each year. From the fourth year after afforestation, the branches and leaves can be pruned every year to harvest raw materials, or the whole plant (including roots) can be dug up to extract paclitaxel. If it is used for greening, it should be trimmed according to the shape. [8]

control of insect

Stem rot of Taxus chinensis is one of the most harmful diseases in the growth period of Taxus chinensis cuttings. Two months after the cutting of Taxus chinensis, stem rot occurred at the stem base of the cutting seedlings (the junction of underground and aboveground cuttings), which started from a single plant and then spread into a whole cluster, resulting in the cutting leaves losing green, dying and falling off. Because the disease mainly occurs in high temperature season in summer and autumn, the harm of high soil temperature to cutting seedlings provides conditions for the invasion of pathogens. The occurrence and prevalence of the disease mainly depend on the temperature in July and August. If the disease occurs early, the seedlings have weak heat tolerance and the disease will be more serious.

Preventive and control measures

1. Reduce the surface soil temperature of seedbed in summer and autumn to prevent the stem base of seedlings from being burned and avoid the invasion of germs caused by wounds;

The second is to increase fertilizer to promote the growth of cutting seedlings and enhance their disease resistance.

3. When pentachloronitrobenzene powder and dichlorvos powder are mixed with water at the concentration of 5g/ kg, the control effect is the best, which is 89%; When carbendazim and thiophanate-methyl WP were mixed with water at the concentration of 4g/ kg, the control effect was the best, reaching 83%.

Fourth, control the disease on a large scale. The alternate use of the above two methods can basically control the occurrence of stem rot of cuttings.