A method for thickening the phloem of short-generation seedlings of medicinal Magnolia

Abstract

The present invention provides a method for thickening the phloem of short-generation magnolia seedlings, belonging to the field of medicinal plant cultivation technology. The method comprises S1: selecting a cultivation medium; S2: controlling water and fertilizer processes; S3: specific maintenance methods; S4: employing dry and wet environmental stress methods; and S5: applying a bark thickening growth agent. By rapidly thickening the bark phloem, the entire plant is felled once the content of its main medicinal components reaches a certain level, and the bark is harvested for medicinal use, thereby achieving intensive cultivation of magnolia seedlings with an ultra-short rotation.

Description

Technical Field

[0001] The invention relates to the technical field of medicinal plant cultivation, in particular to a method for thickening the phloem of short-generation medicinal magnolia seedlings. Background Art

[0002] The phloem is the innermost layer of the bark, just outside the cambium. Unlike the xylem, which is primarily composed of dead cells, the phloem is composed of living cells that transport sap. This transports soluble organic compounds (particularly sucrose) produced by photosynthesis in the tree's leaves into a water-based solution rich in photosynthetic sugars, called sap, to the rest of the plant. This involves transporting sap to non-photosynthetic parts of the plant, such as the roots, or into storage structures, such as tubers or bulbs. Phloem movement is multidirectional, whereas xylem cell movement is unidirectional (upward).

[0003] Studies have shown that the phloem of the bark of species like Magnolia grandiflora and Magnolia dahurica contains compounds that can prevent and treat diabetes and Alzheimer's disease. Extracting large quantities of these active ingredients from magnolia bark is the basis for developing related drugs. The bark of bark-producing trees is typically harvested by large-scale girdling (including the phloem), but this can lead to the death of the trees due to a lack of organic nutrients.

[0004] Chinese patent application CN106417370A discloses a growth agent for promoting bark repair, growth, and regeneration, as well as its preparation method and application. The growth agent for promoting bark repair, growth, and regeneration provided by the present invention can be implemented by spraying, applying, or injecting, and can promote the growth, thickening, and regeneration of the original bark, repair damaged bark, maintain, and grow new and old bark, and prevent the formation of scars, pimples, and cavities in damaged areas. It is particularly suitable for landscape, sidewalks, gardens, and municipal use. However, the invention does not solve the problem that the cultivation medium used is prone to clumping, resulting in poor air permeability, which in turn affects the recovery of the seedling bark. Summary of the Invention

[0005] In view of the above-mentioned defects of the prior art, the technical problem to be solved by the present invention is to provide a planting method that can improve the air permeability of the cultivation medium and reasonably make the bark phloem thicken rapidly.

[0006] To achieve the above objectives, the present invention provides a method for thickening the phloem of short-generation medicinal magnolia seedlings. The method comprises the following steps: rapidly thickening the bark phloem, and when the content of the main medicinal ingredients reaches a certain level, the entire plant is cut down and the bark is harvested for medicinal purposes, thereby realizing intensive cultivation of medicinal magnolia seedlings with an ultra-short rotation period.

[0007] In order to achieve the above-mentioned object of the invention, the present invention adopts the following technical solutions:

[0008] The present invention provides a method for thickening the phloem of short-generation seedlings of medicinal magnolia, comprising the following steps:

[0009] S1. Selection of cultivation medium;

[0010] S2. Control of water and fertilizer process;

[0011] S3. Specific maintenance methods;

[0012] S4, using dry and wet environmental stress methods;

[0013] S5. Apply bark thickening growth agent;

[0014] The above steps are used to achieve phloem thickening of short-generation Magnolia medicinal seedlings.

[0015] Preferably, the selection of the cultivation medium is as follows: a cultivation medium with air permeability and water retention functions is selected so that the roots of the short-generation seedlings of medicinal magnolia can grow better and absorb nutrients.

[0016] Preferably, the cultivation medium is a mixture of sand, red soil and diatomaceous earth, and the mass ratio of sand: red soil: diatomaceous earth is 2-4:4-6:1-2.

[0017] Further preferably, the diatomaceous earth is modified diatomaceous earth, and its preparation method is: 3-5 parts by mass of diatomaceous earth and 0.5-1 parts by mass of sodium lignin sulfonate are mixed uniformly and then dried, and then mixed with 10-20 parts by mass of dimethyl silicone oil, placed in a high-speed disperser for dispersion, allowed to stand, filtered, dried, and then mixed uniformly with 1-2 parts by mass of silica fume to obtain the modified diatomaceous earth.

[0018] Preferably, the control of the water-fertilizer process is as follows: according to the short-cycle bark thickening growth requirements of the medicinal magnolia, nitrogen, phosphorus and potassium fertilizers are applied in spring and summer. The composition of the nitrogen, phosphorus and potassium fertilizers is, by mass, 10-20 parts of ammonium sulfate, 5-15 parts of diammonium phosphate, and 5-15 parts of potassium sulfate. It is applied once every 2-3 weeks, and the dosage each time is 10-20 kg / mu; and the amount of watering is controlled. In the summer from May to August, the seedlings are sprayed with 200-400 ml of water every two days before 10 am or after 4 pm for supplementation. In the winter, 400-600 ml of water is irrigated every week to avoid excessive watering that causes the soil to be too wet. If the surface soil of the seedlings is found to be moist, watering is stopped once, thereby reducing the thickness of the phloem.

[0019] Preferably, the mass ratio of the sandy soil, red soil, and nitrogen, phosphorus, and potassium fertilizers is 2-4:4-6:1-3.

[0020] Preferably, the specific maintenance method is as follows: topping is performed in March each year to inhibit apical dominant growth, dwarf the plants, and promote phloem thickening; at the same time, pulling is performed in May to promote lateral growth, increase lateral branch growth, and improve the bark ratio; the growth status of short-generation medicinal magnolia seedlings is checked, and when pests and diseases are found, prevention and control measures are taken in a timely manner, such as spraying pesticides, removing pest and disease sources, etc., to reduce damage to the plants;

[0021] Preferably, the dry-wet environmental stress method is as follows: facility cultivation, adverse stress, simulated cold-dry alternating environment, carried out in autumn from September to November, all seedlings are placed in a cold storage for seedling hardening, and the cold storage temperature is maintained at ≤10°C. In September, wet environmental stress is carried out, and the seedlings are watered once a day, 100-300 ml each time, to ensure that the soil around the seedlings is moist; in October, dry environmental stress is carried out, and the seedlings are watered once every two weeks, 500-700 ml each time; and the September operation is repeated in November.

[0022] Preferably, the bark thickening growth agent is applied in the following manner:

[0023] M1. Point injection: In June of the second year, inject the bark thickening growth agent. Drill holes on one side of the trunk and inject the bark thickening growth agent into each hole. The next day after the injection, use a wooden stick to knock on the bark to relax the xylem and phloem.

[0024] M2. Linear scratching: Dip the blade of a knife into the bark thickening agent mentioned above and scratch the bark 30-100 cm above the ground. The scratch depth should be enough to reach the wood.

[0025] M3. Half-ring cutting: Make a half-ring cut on one side of the trunk 15-25cm from the ground and 15-25cm below the main branch, then connect the two ends of the upper and lower half-ring cuts vertically, then apply the above-mentioned bark thickening growth agent on the ring cut area, and then wrap the ring cut area.

[0026] Preferably, the bark thickening growth agent in step S5 includes the following components, measured by mass concentration: 50-80 mg / L of forchlorfenuron, 8-10 mg / L of sodium nitrophenolate, 80-180 mg / L of ethephon, 50-300 mg / L of sodium α-naphthyl acetate, 10-800 mg / L of zinc sulfate, 10-800 mg / L of boron sulfate, 2-20 mg / L of nitrogen-fixing bacteria, and 5-50 mg / L of phosphorus bacteria.

[0027] Further preferably, the bark thickening growth agent includes the following components in terms of mass concentration: 60 mg / L of chlorfenapyr, 9 mg / L of sodium nitrophenolate, 140 mg / L of ethephon, 200 mg / L of sodium α-naphthyl acetate, 500 mg / L of zinc sulfate, 600 mg / L of boron sulfate, 10 mg / L of nitrogen-fixing bacteria, and 30 mg / L of phosphorus bacteria.

[0028] The present invention also provides a preparation method of the bark thickening growth agent, which comprises the following steps: dissolving forchlorfenuron, ethephon, sodium α-naphthylacetate and sodium nitrophenolate with ethanol having a volume fraction of 80-95% until they are completely dissolved; then dissolving zinc sulfate, boron sulfate, nitrogen-fixing bacteria and phosphorus bacteria respectively with water; mixing the two solutions, stirring them evenly, and adding water to make up the volume to obtain the bark thickening growth agent of the concentration.

[0029] Compared with the prior art, the present invention has the following beneficial effects:

[0030] The invention effectively increases the thickness of the phloem in the bark of magnolia trees and shortens the rotation period of seedlings. The specific cultivation and maintenance method enables seedlings to better withstand harsh environments such as drought, cold, and strong winds, which is conducive to better growth of the bark of the seedlings.

[0031] The present invention introduces a pore-forming agent into the diatomite to increase the porosity of the diatomite, then introduces dimethyl silicone oil onto the surface to reduce the surface tension of the diatomite, prevent the diatomite from agglomerating, and enhance the air permeability of the cultivation medium, thereby improving the quality of the cultivation medium. Finally, silica fume is added to reduce the viscosity of the dimethyl silicone oil on the diatomite surface and prevent uneven dispersion. The high-quality cultivation medium is more conducive to the growth of seedlings.

[0032] This method combines line and surface scarification, dot injection, and semi-girdling application to apply a bark thickening growth agent at different time periods and locations. This accelerates bark healing and growth, effectively promoting the regeneration of new bark in medicinal magnolia seedlings. This rapid regeneration of new bark aids wound healing after girdling, providing more raw materials for the medicinal plant industry. Furthermore, the growth agent contains biodegradable ingredients, minimizing its environmental impact. The overall technology offers high economic benefits, further improving the yield and quality of medicinal magnolia, promoting the industrialization of magnolia seedling bark, and significantly increasing revenue. DETAILED DESCRIPTION

[0033] The embodiments of the present invention will be described in detail below with reference to examples. However, those skilled in the art will understand that the following examples are only used to illustrate the present invention and should not be regarded as limiting the scope of the present invention.

[0034] Medicinal Magnolia short-generation seedlings with an age of 1-2 years were selected as experimental subjects, with 50 plants in each group, divided into four implementation groups and three control groups. The specific process is as follows:

[0035] Example 1

[0036] A phloem thickening technology for short-generation seedlings of medicinal magnolia comprises the following steps:

[0037] S1. Selection of cultivation medium: Select a cultivation medium with good air permeability and water retention, which is a mixture of sandy soil, red soil, and diatomaceous earth in a mass ratio of 3:5:2; this ensures that the roots of the short-generation Magnolia medicinal seedlings can grow better and absorb nutrients;

[0038] S2 Control of water and fertilizer process: According to the short-cycle bark thickening growth requirements of the medicinal magnolia, nitrogen, phosphorus and potassium fertilizers are applied in spring and summer. The composition of the nitrogen, phosphorus and potassium fertilizers is 150g ammonium sulfate, 100g diammonium phosphate, and 100g potassium sulfate. It is applied once every 2-3 weeks, and the amount used each time is 15 kg / mu; the mass ratio of nitrogen, phosphorus and potassium fertilizers to sandy soil is 2:3; and the amount of watering is controlled. In the summer from May to August, the seedlings are sprayed with 300ml of water every two days before 10 am or after 4 pm for supplementation. In the winter, 500ml of water is irrigated every week to avoid excessive watering that causes the soil to be too wet. If the surface soil of the seedlings is found to be moist, watering is stopped once, thereby reducing the thickness of the phloem;

[0039] S3 Specific maintenance methods: Topping is performed in March each year to inhibit apical dominant growth, dwarf the plants, and promote phloem thickening. At the same time, pulling is performed in May to promote lateral growth, increase lateral branch growth, and improve the bark ratio. Regularly check the growth status of short-generation medicinal magnolia seedlings and take preventive measures when diseases and pests are found, such as spraying pesticides and removing the source of diseases and pests, to reduce damage to the plants.

[0040] S4 uses a dry-wet environment stress method: facility cultivation, adverse stress, and simulated cold-dry alternating environment; carried out from September to November in autumn, all seedlings were placed in a cold storage for seedling hardening, and the cold storage temperature was maintained at ≤10℃. In September, a wet environment stress was applied, and the seedlings were watered once a day, 200ml each time, to ensure that the soil around the seedlings was moist; in October, a dry environment stress was applied, and the seedlings were watered once every two weeks, 600ml each time; the September operation was repeated in November;

[0041] S5: Bark thickening agent was injected in June of the second year. Phloem thickness was recorded before injection. Thickening and survival rates were calculated in December of the third year. No fertilizer was applied during the planting process, and watering was not controlled. Only the survival of the seedlings was ensured.

[0042] The preparation method of the bark thickening growth agent is as follows: forchlorfenuron, ethephon, sodium α-naphthylacetate, sodium nitrophenolate, zinc sulfate, boron sulfate, nitrogen-fixing bacteria, and phosphorus bacteria are weighed in proportion; forchlorfenuron, ethephon, sodium α-naphthylacetate, and sodium nitrophenolate are solubilized with 95% ethanol by volume until they are completely dissolved; the zinc sulfate, boron sulfate, nitrogen-fixing bacteria, and phosphorus bacteria are respectively dissolved in water; the two solutions are mixed, stirred evenly, and water is added to the volume to obtain the bark thickening growth agent, wherein the forchlorfenuron contains 60 mg / L, sodium α-naphthylacetate 200 mg / L, ethephon 140 mg / L, sodium nitrophenolate 9 mg / L, zinc sulfate 500 mg / L, boron sulfate 600 mg / L, nitrogen-fixing bacteria 10 mg / L, and phosphorus bacteria 30 mg / L.

[0043] The method of using the bark thickening growth agent is as follows:

[0044] M1. Point injection: Use a drill to drill six 5mm diameter holes on one side of the trunk. The depth of the holes depends on the size of the tree, but usually needs to reach the area between the xylem and phloem. Then, inject 10ml of the above-mentioned bark thickening agent into each hole with a syringe. The next day after the injection, gently tap the holes with a wooden stick to relax the area between the xylem and phloem. Inject once every two weeks for a total of six times to ensure that the cambium on one side of the trunk quickly grows a new cortex, thereby achieving the goal of thickening the bark.

[0045] M2. Linear scratches: At 50 cm from the ground, use a knife to make several horizontal oblique cuts, with the depth being enough to slightly damage the wood. Each time you make an oblique cut, dip the blade into the bark thickening agent mentioned above. Leave gaps between the cuts to allow more organic nutrients to gather and accumulate on the bark. After 3 days, if the peeled area is yellow-green, it means the wound has healed and new bark will gradually grow, further thickening the bark.

[0046] M3. Semi-girdling: Seedlings to be treated with semi-girdling should have actively growing trunks. This treatment should be performed in June, during the hot season, with temperatures ranging from 25°C to 35°C and a relative humidity of approximately 80%. A semi-girdling cut should be made 20 cm above the ground on one side of the trunk and 20 cm below the main branch. The upper and lower semi-girdling cuts should then be connected by longitudinal cuts. The aforementioned bark thickening agent should then be applied to the girdling area. The area should then be wrapped with two layers of colored plastic film of equal length, covering the girdling area and securely tied. The wound surface should be carefully protected and protected with plastic film, which should be taped to the trunk. This will promote rapid regeneration of new bark.

[0047] Example 2

[0048] A phloem thickening technology for short-generation seedlings of medicinal magnolia, comprising:

[0049] S1 Selection of cultivation medium: Select a cultivation medium with good air permeability and water retention. The cultivation medium is a mixture of sandy soil, red soil, and modified diatomaceous earth in a mass ratio of 2:4:0.3; to ensure that the roots of short-generation medicinal magnolia seedlings can grow normally and absorb nutrients; the preparation method of the modified diatomaceous earth is as follows: 400g of diatomaceous earth and 100g of sodium lignin sulfonate are mixed evenly, dried at 60°C for 2h, then mixed with 200g of dimethyl silicone oil, placed in a high-speed disperser at a speed of 6000rpm and dispersed for 40min, allowed to stand, filtered, dried, and evenly mixed with 150g of silica ash to obtain the modified diatomaceous earth.

[0050] S2 Control of water and fertilizer process: According to the short-cycle bark thickening growth requirements of the medicinal magnolia, nitrogen, phosphorus and potassium fertilizers are applied in spring and summer. The composition of the nitrogen, phosphorus and potassium fertilizers is 50g ammonium sulfate, 50g diammonium phosphate, and 50g potassium sulfate. It is applied once every 2-3 weeks, and the amount used each time is 10 kg / mu. The mass ratio of nitrogen, phosphorus and potassium fertilizers to sandy soil is 1:2. The amount of watering is controlled. In the summer from May to August, the seedlings are sprayed with 200ml of water every two days before 10 am or after 4 pm for supplementation. In the winter, 400ml of water is irrigated every week to avoid excessive watering that causes the soil to become too wet. If the surface soil of the seedlings is found to be moist, watering is stopped once, thereby reducing the thickness of the phloem.

[0051] S3 Maintenance Methods: Top the trees in March each year to inhibit apical dominant growth, dwarf the plants, and promote phloem thickening. At the same time, pull the trees in May to promote lateral growth, increase lateral branch growth, and improve the bark ratio. Regularly check the growth status of short-generation medicinal magnolia seedlings. If pests and diseases are found, take timely prevention and control measures, such as spraying pesticides and removing pest sources, to reduce damage to the plants.

[0052] S4 uses a dry-wet environment stress method: facility cultivation, adverse stress, and simulated cold-dry alternating environment; carried out from September to November in autumn, all seedlings were placed in a cold storage for seedling hardening, and the cold storage temperature was maintained at ≤10℃. In September, a wet environment stress was applied, and the seedlings were watered once a day, 200ml each time, to ensure that the soil around the seedlings was moist; in October, a dry environment stress was applied, and the seedlings were watered once every two weeks, 600ml each time; the September operation was repeated in November;

[0053] S5: Bark thickening agent was injected in June of the second year. Phloem thickness was recorded before injection. Thickening and survival rates were calculated in December of the third year. No fertilizer was applied during the planting process, and watering was not controlled. Only the survival of the seedlings was ensured.

[0054] The preparation method of the bark thickening growth agent is as follows: forchlorfenuron, ethephon, sodium α-naphthylacetate, sodium nitrophenolate, zinc sulfate, boron sulfate, nitrogen-fixing bacteria, and phosphorus bacteria are weighed in proportion; forchlorfenuron, ethephon, sodium α-naphthylacetate, and sodium nitrophenolate are solubilized with 85% ethanol by volume until they are completely dissolved; the zinc sulfate, boron sulfate, nitrogen-fixing bacteria, and phosphorus bacteria are respectively dissolved in water; the two solutions are mixed, stirred evenly, and water is added to the volume to obtain the bark thickening growth agent, wherein the forchlorfenuron contains 60 mg / L, sodium α-naphthylacetate 200 mg / L, ethephon 140 mg / L, sodium nitrophenolate 9 mg / L, zinc sulfate 500 mg / L, boron sulfate 600 mg / L, nitrogen-fixing bacteria 10 mg / L, and phosphorus bacteria 30 mg / L.

[0055] The bark thickening agent is administered by point injection: six 5mm diameter holes are drilled on one side of the trunk using a drill bit. The depth of the holes depends on the size of the tree, but typically needs to reach the area between the xylem and phloem. 10ml of the agent is then injected into each hole using a syringe. The next day, the agent is gently tapped with a wooden stick to loosen the area between the xylem and phloem. Injections are repeated every two weeks for a total of seven times to ensure that the cambium on one side of the trunk quickly grows a new cortex, thereby thickening the bark.

[0056] Example 3

[0057] A phloem thickening technology for short-generation seedlings of medicinal magnolia, comprising:

[0058] S1. Selection of cultivation medium: Select a cultivation medium with good air permeability and water retention, which is a mixture of sandy soil, red soil, and diatomaceous earth in a mass ratio of 2:4:0.3; to ensure that the roots of the short-generation Magnolia medicinal seedlings can grow normally and absorb nutrients;

[0059] S2 Control of water and fertilizer process: According to the short-cycle bark thickening growth requirements of the medicinal magnolia, nitrogen, phosphorus and potassium fertilizers are applied in spring and summer. The composition of the nitrogen, phosphorus and potassium fertilizers is 50g ammonium sulfate, 50g diammonium phosphate, and 50g potassium sulfate. It is applied once every 2-3 weeks, and the amount used each time is 10 kg / mu. The mass ratio of nitrogen, phosphorus and potassium fertilizers to sandy soil is 1:2. The amount of watering is controlled. In the summer from May to August, the seedlings are sprayed with 200ml of water every two days before 10 am or after 4 pm for supplementation. In the winter, 400ml of water is irrigated every week to avoid excessive watering that causes the soil to become too wet. If the surface soil of the seedlings is found to be moist, watering is stopped once, thereby reducing the thickness of the phloem.

[0060] S3 Maintenance Methods: Top the trees in March each year to inhibit apical dominant growth, dwarf the plants, and promote phloem thickening. At the same time, pull the trees in May to promote lateral growth, increase lateral branch growth, and improve the bark ratio. Regularly check the growth status of short-generation medicinal magnolia seedlings. If pests and diseases are found, take timely prevention and control measures, such as spraying pesticides and removing pest sources, to reduce damage to the plants.

[0061] S4 uses a dry-wet environment stress method: facility cultivation, adverse stress, and simulated cold-dry alternating environment; carried out in autumn from September to November, all seedlings were placed in a cold storage for seedling hardening, and the cold storage temperature was maintained at ≤10℃. In September, a wet environment stress was applied, and the seedlings were watered once a day, 400ml each time, to ensure that the soil around the seedlings was moist; in October, a dry environment stress was applied, and the seedlings were watered once every two weeks, 700ml each time; the September operation was repeated in November;

[0062] S5: Bark thickening agent was injected in June of the second year. Phloem thickness was recorded before injection. Thickening and survival rates were calculated in December of the third year. No fertilizer was applied during the planting process, and watering was not controlled. Only the survival of the seedlings was ensured.

[0063] The preparation method of the bark thickening growth agent is as follows: forchlorfenuron, ethephon, sodium α-naphthylacetate, sodium nitrophenolate, zinc sulfate, boron sulfate, nitrogen-fixing bacteria, and phosphorus bacteria are weighed in proportion; forchlorfenuron, ethephon, sodium α-naphthylacetate, and sodium nitrophenolate are solubilized with 95% ethanol by volume until they are completely dissolved; the zinc sulfate, boron sulfate, nitrogen-fixing bacteria, and phosphorus bacteria are then dissolved in water respectively; the two solutions are mixed, stirred evenly, and water is added to the volume to obtain the bark thickening growth agent, wherein the forchlorfenuron contains 80 mg / L, sodium α-naphthylacetate 180 mg / L, ethephon 180 mg / L, sodium nitrophenolate 10 mg / L, zinc sulfate 800 mg / L, boron sulfate 800 mg / L, nitrogen-fixing bacteria 20 mg / L, and phosphorus bacteria 50 mg / L.

[0064] The bark thickening agent is used by scratching the tree surface: it is important to apply stress one month before scratching the tree surface to simulate a cold-dry alternating environment, and record the thickness of the magnolia phloem. At 30 cm from the ground, make several horizontal oblique cuts with a knife, the depth of which should slightly damage the xylem. Each time you make an oblique cut, dip the blade in the bark thickening agent, leaving gaps between the cuts to allow more organic nutrients to gather and accumulate on the bark. After three days, if the peeled area is yellow-green, it means the wound has healed, and new bark will gradually grow, further thickening the bark.

[0065] Example 4

[0066] A short-generation phloem thickening technology for medicinal magnolia seedlings is similar to Example 1, except that the bark thickening growth agent is applied by semi-girdling: it should be noted that adverse stress should be carried out one month before semi-girdling, simulating a cold-dry alternating environment, and recording the phloem thickness of the magnolia. The seedlings to be applied by semi-girdling need to have a trunk with vigorous growth, and the operation should be carried out in July, a high temperature season with an air temperature of 25°C to 35°C and a relative humidity of about 80%. During the operation, a semi-girdling cut should be made on one side of the trunk 25 cm from the ground and 25 cm below the main branch, and then the upper and lower semi-girdling ends should be connected by longitudinal cuts. Subsequently, the bark thickening growth agent is applied to the girdling area, and then wrapped with two layers of colored plastic film of equal length to cover the girdling area and tie it tightly; during the operation, the wound surface must not be damaged or contaminated, and the wound surface must be surrounded and cared for with plastic film, and the wound surface should be pasted on the trunk with adhesive tape on all sides, so that new bark regeneration can be quickly promoted.

[0067] Comparative Example 1

[0068] A phloem thickening technology for short-generation seedlings of Magnolia medica is similar to Example 1, except that the cultivation medium used is common garden soil; and no specific growth agent is applied. Data such as the tree thickening and survival rate are collected in June of the second year and December of the third year after planting.

[0069] Comparative Example 2

[0070] A technique for thickening the phloem of short-generation Magnolia medica seedlings is similar to that described in Example 1, except that the cultivation medium used is common garden soil. No fertilizer is applied during the planting process, and watering is not controlled, ensuring the survival of the seedlings. Furthermore, no specific growth enhancers are used. Data on tree phloem thickening and survival rates are collected in June of the second year after planting and in December of the third year after planting.

[0071] Comparative Example 3

[0072] A technique for thickening the phloem of short-generation Magnolia medica seedlings is similar to Example 1, except that conventional garden soil is used as the cultivation medium. No fertilizer is applied and watering is not controlled during the planting process, ensuring only the normal survival of the seedlings. In June of the third year of planting, root irrigation with a specific growth agent is performed, with each seedling receiving 500 ml of the prepared growth agent. The bark-thickening growth agent applied is 50 mg / L of forchlorfenuron, 100 mg / L of sodium α-naphthylacetate, 80 mg / L of ethephon, 8 mg / L of sodium nitrophenolate, 500 mg / L of boron sulfate, 10 mg / L of nitrogen-fixing bacteria, and 30 mg / L of phosphate bacteria.

[0073] The thickening conditions and survival rates of the short-generation seedlings of Magnolia officinalis cultivated by the phloem thickening technology of Examples 1-4 and Comparative Examples 1-3 are shown in Table 1:

[0074] Table 1 Thickening of seedlings and survival rate results

[0075]

[0076] The experimental data in Table 1 demonstrates that the cultivation and maintenance methods, specific growth agents, and their specific application methods developed by the present invention can effectively increase phloem thickness in Magnolia medica and facilitate the intensive cultivation of Magnolia medica seedlings with ultra-short rotations. The method and growth agent formulation used in Example 2 are the most preferred, likely due to the improved quality of the cultivation medium due to the modified diatomaceous earth. High-quality cultivation media are more conducive to the growth of the seedling bark, effectively increasing seedling survival rates and reducing disease incidence.

[0077] The above embodiments are merely preferred technical solutions of the present invention and should not be construed as limiting the present invention. The scope of protection of the present invention shall be the technical solutions set forth in the claims, including equivalent alternatives to the technical features of the technical solutions set forth in the claims. In other words, equivalent alternatives and improvements within this scope are also within the scope of protection of the present invention.

Claims

1. A method for thickening the phloem of short-generation seedlings of medicinal magnolia, characterized by: The following steps are involved: S1. Selection of cultivation medium: Choose a cultivation medium with good air permeability and water retention, so that the roots of short-generation medicinal magnolia seedlings can grow better and absorb nutrients; S2. Control of water and fertilizer process: According to the short-cycle bark thickening growth requirements of the medicinal magnolia, nitrogen, phosphorus and potassium fertilizers are applied in spring and summer. The nitrogen, phosphorus and potassium fertilizers are composed of 10-20 parts of ammonium sulfate, 5-15 parts of diammonium phosphate, and 5-15 parts of potassium sulfate, by mass, and applied once every 2-3 weeks at a dosage of 10-20 kg / mu each time; and the amount of watering is controlled. In the summer from May to August, the seedlings are sprayed with 200-400 ml of water every two days before 10 am or after 4 pm for supplementation. In the winter, 400-600 ml of water is irrigated weekly to avoid excessive watering that causes the soil to become too wet. If the surface soil of the seedlings is found to be moist, watering is stopped once, thereby reducing the thickness of the phloem; S3. Maintenance: Topping is performed in March each year to inhibit apical dominant growth, dwarf the plants, and promote phloem thickening. At the same time, traction is performed in May to promote lateral growth, increase lateral branch growth, and improve the bark ratio. The growth status of short-generation medicinal magnolia seedlings is checked, and timely prevention and control measures are taken when diseases and insect pests are found. S4, using dry and wet environmental stress methods; S5. Apply bark thickening growth agent; The cultivation medium is a mixture of sand, red soil and diatomaceous earth, wherein the mass ratio of sand: red soil: diatomaceous earth is 2-4:4-6:1-2; The diatomaceous earth is modified diatomaceous earth, and its preparation method is as follows: 3-5 parts by mass of diatomaceous earth and 0.5-1 parts by mass of sodium lignin sulfonate are uniformly mixed and then dried, and then mixed with 10-20 parts by mass of dimethyl silicone oil, placed in a high-speed disperser for dispersion, allowed to stand, filtered, dried, and then uniformly mixed with 1-2 parts by mass of silica fume to obtain the modified diatomaceous earth; The above steps are used to achieve phloem thickening of short-generation Magnolia medicinal seedlings.

2. The method for thickening the phloem of short-generation seedlings of Magnolia officinalis according to claim 1, characterized in that: The dry-wet environment stress method is specifically as follows: facility cultivation, adverse environment stress, simulating a cold-dry alternating environment, which is carried out from September to November in autumn, and all seedlings are placed in a cold storage for seedling hardening, and the cold storage temperature is maintained at ≤10°C; in September, a wet environment stress is carried out, and the seedlings are watered once a day, 100-300 ml each time, to ensure that the soil around the seedlings is in a moist state; in October, a dry environment stress is carried out, and the seedlings are watered once every two weeks, 500-700 ml each time; and the September operation is repeated in November.

3. The method for thickening the phloem of short-generation seedlings of Magnolia officinalis according to claim 1, characterized in that: The method of applying the bark thickening growth agent is as follows: M1. Point injection: In June of the second year, inject the bark thickening growth agent. Drill holes on one side of the trunk and inject the bark thickening growth agent into each hole. The next day after the injection, use a wooden stick to knock on the bark to relax the xylem and phloem. M2. Linear scratching: Dip the blade of a knife into the bark thickening agent mentioned above and scratch the bark 30-100 cm above the ground. The scratch depth should be enough to reach the wood. M3. Half-ring cutting: Make a half-ring cut on one side of the trunk 15-25cm from the ground and 15-25cm below the main branch, then connect the two ends of the upper and lower half-ring cuts vertically, then apply the above-mentioned bark thickening growth agent on the ring cut area, and then wrap the ring cut area.

4. The method for thickening the phloem of short-generation seedlings of Magnolia officinalis according to claim 3, characterized in that: The bark thickening and growth agent includes the following components in mass concentration: 50-80 mg / L of forchlorfenuron, 8-10 mg / L of sodium nitrophenolate, 80-180 mg / L of ethephon, 50-300 mg / L of sodium α-naphthyl acetate, 10-800 mg / L of zinc sulfate, 10-800 mg / L of boron sulfate, 2-20 mg / L of nitrogen-fixing bacteria, and 5-50 mg / L of phosphorus bacteria.

5. The method for thickening the phloem of short-generation seedlings of Magnolia officinalis according to claim 4, characterized in that: The bark thickening growth agent includes the following components, calculated by mass concentration: 60 mg / L of forchlorfenuron, 9 mg / L of sodium nitrophenolate, 140 mg / L of ethephon, 200 mg / L of sodium α-naphthyl acetate, 500 mg / L of zinc sulfate, 600 mg / L of boron sulfate, 10 mg / L of nitrogen-fixing bacteria, and 30 mg / L of phosphorus bacteria.

6. The method for thickening the phloem of short-generation seedlings of Magnolia officinalis according to claim 4 or 5, characterized in that: The preparation method of the bark thickening growth agent comprises the following steps: dissolving forchlorfenuron, ethephon, sodium α-naphthylacetate and sodium nitrophenolate with ethanol having a volume fraction of 80-95% until they are completely dissolved; then dissolving zinc sulfate, boron sulfate, nitrogen-fixing bacteria and phosphorus bacteria in water respectively; mixing the two solutions, stirring them evenly, and adding water to adjust the volume to obtain the bark thickening growth agent of the concentration.

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