A method for controlling the height-to-diameter ratio of camphor trees used in afforestation

Abstract

This invention discloses a method for controlling the height-to-diameter ratio of camphor trees used in afforestation, belonging to the field of camphor seedling technology. This invention uses soybean lecithin to encapsulate chlormequat chloride to prepare a slow-release conditioner, which is sprayed during the rapid growth period of camphor seedlings. The conditioner slowly releases chlormequat chloride to act on the seedlings, inhibiting the growth of seedling height. At the same time, combined with nutrient solution and drought stress, it reduces the seedling height while effectively promoting the growth of ground diameter, resulting in robust and high-quality camphor seedlings, thus improving the quality of the cultivated camphor seedlings.

Description

Technical Field

[0001] This invention relates to the field of camphor tree seedling technology, and in particular to a method for controlling the height-to-diameter ratio of camphor trees used in afforestation. Background Technology

[0002] The height-to-diameter ratio (HDR) of seedlings is the ratio of seedling height to ground diameter, reflecting the balance between seedling height and thickness. HDR is a good indicator of seedling resistance and afforestation survival rate. Generally, the thinner and taller the seedling, the weaker its resistance and the lower its afforestation survival rate; conversely, the shorter and thicker the seedling, the stronger its resistance and the higher its afforestation survival rate. In actual afforestation, an excessively high HDR will affect the afforestation survival rate, while an excessively low HDR will affect seedling growth. To ensure afforestation efficiency, it is necessary to select seedlings with a suitable HDR for afforestation.

[0003] Camphor tree (Cinnamomum camphora) is an evergreen tree belonging to the genus Cinnamomum in the family Lauraceae. Also known as camphor, fragrant camphor, oil camphor, and black camphor, it is widely distributed south of the Yangtze River. Camphor wood is of high quality, from which camphor oil and aromatic oils can be extracted. Its beautiful tree shape, dark green foliage, relatively fast growth, and well-developed crown and root system make it suitable for timber forests, making it one of my country's important afforestation tree species. However, in camphor afforestation, the use of seedlings with an excessively high height-to-diameter ratio (HDR) often leads to low survival rates, easy lodging, and crooked trunks after planting. Conventional methods to reduce the HDR typically involve pruning and spraying chemical agents. However, camphor is a species with weak apical dominance, and pruning is not very effective in reducing the HDR. Spraying chemical agents often requires multiple applications, which can easily result in an excessively high or low HDR due to improper dosage, reducing seedling quality and wasting chemical agents.

[0004] Therefore, it is currently necessary to find a method to regulate the height-to-diameter ratio of camphor trees to control the height-to-diameter ratio of camphor trees used for afforestation within a suitable range, so as to cultivate high-quality camphor seedlings. Summary of the Invention

[0005] Therefore, the purpose of this invention is to provide a method for controlling the height-to-diameter ratio of camphor trees used in afforestation, thereby solving the problems of unsuitable height-to-diameter ratio and poor seedling quality obtained by conventional methods for cultivating camphor seedlings.

[0006] The present invention solves the above-mentioned technical problems through the following technical means:

[0007] A method for controlling the height-to-diameter ratio of camphor trees used in afforestation, the method is as follows:

[0008] (1) Camphor trees are sown in mid-March and managed according to conventional methods, maintaining soil moisture content at 65-70% during the period; thinning is carried out in May after the seedlings grow to a height of ≥5cm.

[0009] (2) When the seedlings are cultivated to the beginning of July, spray the conditioner and stop watering. Apply nutrient solution 3-5 days after spraying the conditioner. Restart watering 3-4 days after applying the nutrient solution to maintain soil moisture at 50-55%.

[0010] (3) In early August, follow the steps in (1) to spray the conditioner, stop watering, and apply nutrient solution. After applying the nutrient solution for 5-7 days, start watering again to ensure soil moisture of 65-70%. Then apply nutrient solution again in mid-September. By March of the second year, seedlings with a height-to-diameter ratio of 70-100 can be transplanted for afforestation.

[0011] This invention involves sowing and cultivating camphor trees until July, when the seedlings enter their rapid growth period. At this time, a conditioner containing chlormequat chloride (CSC) is sprayed. CSC regulates hormones in the seedlings, inhibiting height growth, and, in conjunction with nutrient solution, promotes better diameter growth, thus cultivating high-quality camphor seedlings with a good height-to-diameter ratio suitable for afforestation. Simultaneously, watering is stopped to induce drought stress in the seedlings, promoting the transport of growth substances to the lower part of the seedlings and further promoting diameter growth. Then, by mid-September, the seedlings enter the hardening period. At this time, the components in the nutrient solution work together to promote lignification. Through the combined effects of the conditioner, drought stress, and nutrient solution, the height-to-diameter ratio of the seedlings is controlled, and the degree of lignification is improved, thus cultivating high-quality camphor seedlings.

[0012] Furthermore, the conditioning agent in step (2) includes the following raw materials:

[0013] Chlormequat chloride, soybean lecithin, Tween-80, chloroform, vitamin C, 4-tert-butylcyclohexanol, dimethylglyoxal.

[0014] Furthermore, the preparation method of the conditioner is as follows:

[0015] A: Dissolve soybean lecithin in Tween-80, dilute with water, add dimethylglyoxal, and heat in a reaction vessel at 60-70℃ for 2-4 hours. After the reaction is complete, cool to room temperature and let stand overnight. Then add 4-tert-butylcyclohexanol, heat to 60-70℃ and react for 1-2 hours. After the reaction is complete, cool naturally to room temperature, and then place in an environment of 4-8℃ for aging treatment for 12-24 hours before drying to obtain pretreated soybean lecithin.

[0016] B: Dissolve the pretreated soybean lecithin in chloroform, add chlormequat chloride and mix and homogenize. After homogenization, heat in a water bath at 70-80℃ for 20-40 minutes, then cool to 40-50℃ and add vitamin C. Stir continuously for 5-10 minutes, then cool to room temperature and dry to obtain the conditioning agent.

[0017] Traditionally, chlormequat chloride is prepared as an aqueous solution for spraying. However, after spraying, it is easily lost into the soil and rapidly decomposed by microbial enzymes, requiring multiple sprays, resulting in waste and reduced effectiveness. Therefore, this invention uses soybean lecithin, which has a good promoting effect on plant growth, as an encapsulating material to coat chlormequat chloride into a conditioner. After spraying, soybean lecithin hydrophobically associates with the waxy layer on the leaf surface of camphor seedlings, thus adhering well to the plant surface and inhibiting loss. At the same time, soybean lecithin slowly releases chlormequat chloride, allowing it to continuously enter the seedlings in small amounts, inhibiting excessive growth in seedling height and promoting growth in ground diameter.

[0018] However, soybean lecithin is easily decomposed by oxygen and light under natural conditions, affecting the sustained stability of chlormequat chloride release. Therefore, this invention first reacts soybean lecithin with dimethyl ethyl ketone (DME). The DME reacts with the chemical bonds in soybean lecithin to form a conjugated structure, thereby improving the stability of the molecular chain. Then, 4-tert-butylcyclohexanol is added and heated to react. The 4-tert-butylcyclohexanol binds to the soybean lecithin molecular chain, changing its molecular structure and reducing its reactivity. This results in pretreated soybean lecithin with low reactivity and high stability, which encapsulates chlormequat chloride, allowing the encapsulated chlormequat chloride to be released continuously and slowly, ensuring its efficacy.

[0019] Furthermore, in step A, the mass ratio of soybean lecithin, Tween-80, dimethyl ethyl ketone, and 4-tert-butylcyclohexanol is (0.5-1):(1-1.5):(0.02-0.05):(0.01-0.02).

[0020] Furthermore, in step B, the mass ratio of pretreated soybean lecithin, chloroform, chlormequat chloride, and vitamin C is (0.5-1):(0.8-1.2):(0.004-0.008):(0.005-0.01).

[0021] Furthermore, in step B, the homogenization speed is 1000-1500 rpm, and the homogenization time is 3-5 min.

[0022] Furthermore, the method for preparing the nutrient solution is as follows:

[0023] Ammonium sulfate and potassium dihydrogen phosphate are mixed and then added to water and stirred to dissolve. Proline is then added and mixed evenly to obtain a nutrient solution.

[0024] Furthermore, the mass ratio of ammonium sulfate, potassium dihydrogen phosphate, and proline is (20-30):(15-25):(2-3).

[0025] Furthermore, when spraying the conditioner, the conditioner and water are mixed at a mass ratio of 1:100 to form a suspension before spraying, and the spraying amount is 10-20g / plant.

[0026] Furthermore, the amount of nutrient solution applied is 15-30g / plant.

[0027] Beneficial effects:

[0028] This invention prepares a conditioner by encapsulating chlormequat chloride in soybean lecithin. When sprayed during the rapid growth period of camphor seedlings, the conditioner works in conjunction with drought stress and nutrient solution to ensure seedling height while promoting effective growth of seedling diameter and improving seedling quality. Detailed Implementation

[0029] The present invention will be described in detail below with reference to specific embodiments:

[0030] This invention discloses a method for controlling the height-to-diameter ratio of camphor trees used in afforestation. A conditioning agent is prepared before camphor seedling cultivation, as detailed below.

[0031] Example 1: Preparation of Conditioner

[0032] A: Dissolve 0.6 kg of soybean lecithin in 1.2 kg of Tween-80, dilute with 3.6 kg of water, add 0.03 kg of dimethyl ethyl ketone, heat in a reactor at 65°C for 3 hours, cool to room temperature and let stand overnight after the reaction is complete, then add 0.015 kg of 4-tert-butylcyclohexanol, heat to 65°C and react for 1-2 hours, cool naturally to room temperature after the reaction is complete, then let stand at 6°C for 16 hours and dry at 45°C to obtain pretreated soybean lecithin;

[0033] B: Dissolve 0.6 kg of pretreated soybean lecithin in 1 kg of chloroform, add 0.006 kg of chlormequat chloride and mix. Homogenize at 1200 rpm for 4 min. After homogenization, heat in a 75℃ hot water bath for 30 min. Then cool to 45℃ and add 0.007 kg of vitamin C. Stir continuously for 8 min and cool to room temperature. Then spray dry at an inlet air temperature of 120℃ and an outlet air temperature of 80℃ to obtain the conditioner.

[0034] Example 2: Preparation of Conditioner II

[0035] A: Dissolve 0.5 kg of soybean lecithin in 1 kg of Tween-80, dilute with 3 kg of water, add 0.02 kg of dimethyl ethyl ketone, heat in a reactor at 60°C for 2 h, cool to room temperature and let stand overnight after the reaction is complete, then add 0.01 kg of 4-tert-butylcyclohexanol, heat to 60°C and react for 1.5 h, cool naturally to room temperature after the reaction is complete, then place in a 4°C environment for aging for 12 h and dry at 45°C to obtain pretreated soybean lecithin;

[0036] B: Dissolve 0.5 kg of pretreated soybean lecithin in 0.8 kg of chloroform, add 0.004 kg of chlormequat chloride and mix. Homogenize at 1000 rpm for 5 min. After homogenization, heat in a 70℃ hot water bath for 40 min. Then cool to 40℃ and add 0.005 kg of vitamin C. Stir continuously for 10 min and cool to room temperature. Then spray dry at an inlet air temperature of 120℃ and an outlet air temperature of 80℃ to obtain the conditioner.

[0037] Example 3: Preparation of Conditioner

[0038] A: Dissolve 1 kg of soybean lecithin in 1.5 kg of Tween-80, dilute with 4.5 kg of water, add 0.05 kg of dimethyl ethyl ketone, heat in a reactor at 70°C for 2 hours, cool to room temperature and let stand overnight after the reaction is complete, then add 0.02 kg of 4-tert-butylcyclohexanol, heat to 70°C and react for 1 hour, cool naturally to room temperature after the reaction is complete, then place in a 6°C environment for aging for 24 hours, and then dry at 45°C to obtain pretreated soybean lecithin;

[0039] B: Dissolve 1 kg of pretreated soybean lecithin in 1.2 kg of chloroform, add 0.008 kg of chlormequat chloride and mix. Homogenize at 1500 rpm for 3 min. After homogenization, heat in a water bath at 80℃ for 20 min. Then cool to 50℃ and add 0.01 kg of vitamin C. Stir continuously for 5 min and cool to room temperature. Then spray dry at an inlet air temperature of 120℃ and an outlet air temperature of 80℃ to obtain the conditioner.

[0040] Comparative Example 1: Preparation of Conditioner

[0041] In contrast to Example 1, the only difference is that diacetyl was not added in step A of the preparation of the conditioner in Comparative Example 1, as detailed below:

[0042] A: Dissolve 0.6 kg of soybean lecithin in 1.2 kg of Tween-80, dilute with 3.6 kg of water, add 0.015 kg of 4-tert-butylcyclohexanol, heat to 65℃ and react for 1-2 h. After the reaction is complete, cool naturally to room temperature, then let stand at 6℃ for 16 h and dry at 45℃ to obtain pretreated soybean lecithin.

[0043] B: Same as Example 1.

[0044] Comparative Example 2: Preparation of Conditioner

[0045] Compared with Example 1, the only difference is that 4-tert-butylcyclohexanol was not added in step A of the preparation of the conditioner in Comparative Example 2, as shown below:

[0046] A: Dissolve 0.6 kg of soybean lecithin in 1.2 kg of Tween-80, dilute with 3.6 kg of water, add 0.03 kg of dimethyl ethyl ketone, heat in a reactor at 65°C for 3 hours, cool to room temperature and let stand overnight after the reaction is complete, then let stand at 6°C for 16 hours and dry at 45°C to obtain pretreated soybean lecithin.

[0047] B: Same as Example 1.

[0048] Comparative Example 3: Preparation of Conditioner

[0049] Compared with Example 1, the only difference is that in Comparative Example 3, the conditioner preparation step A does not involve a static aging treatment, as detailed below:

[0050] A: Dissolve 0.6 kg of soybean lecithin in 1.2 kg of Tween-80, dilute with 3.6 kg of water, add 0.03 kg of dimethyl ethyl ketone, heat in a reactor at 65°C for 3 hours, cool to room temperature and let stand overnight after the reaction is complete, then add 0.015 kg of 4-tert-butylcyclohexanol, heat to 65°C and react for 1-2 hours, cool naturally to room temperature after the reaction is complete, and dry at 45°C to obtain pretreated soybean lecithin;

[0051] B: Same as Example 1.

[0052] Comparative Example 4: Preparation of Conditioner

[0053] In contrast to Example 1, the only difference is that vitamin C was not added in step B of the preparation of the conditioner in Comparative Example 4, as detailed below:

[0054] A: Same as Example 1;

[0055] B: Dissolve 0.6 kg of pretreated soybean lecithin in 1 kg of chloroform, add 0.006 kg of chlormequat chloride and mix. Homogenize at 1200 rpm for 4 min. After homogenization, heat in a 75℃ hot water bath for 30 min and cool to room temperature. Then spray dry at an inlet air temperature of 120℃ and an outlet air temperature of 80℃ to obtain the conditioner.

[0056] Example 4: Seedling cultivation method for controlling the height-to-diameter ratio of camphor trees

[0057] The conditioner used in this embodiment is the conditioner prepared in Example 1;

[0058] The nutrient solution used in this embodiment is prepared as follows: 25g of ammonium sulfate and 20g of potassium dihydrogen phosphate are mixed and added to 4.5kg of water and stirred to dissolve. Then, 2.5g of proline is added and mixed evenly to obtain the nutrient solution.

[0059] (1) Sow camphor trees in mid-March and carry out watering and fertilization management according to conventional methods to maintain soil moisture at 65-70%; after the seedlings grow to a height of ≥5cm in May, thin them out according to conventional methods.

[0060] (2) When the seedlings are cultivated to the beginning of July, the conditioner and water are mixed at a mass ratio of 1:100 to form a suspension. Then, spray the suspension at a rate of 15g / plant and stop watering. Four days after spraying the conditioner, apply nutrient solution at a rate of 20g / plant. Three days after applying the nutrient solution, start watering again to maintain soil moisture at 50-55%.

[0061] (3) In early August, follow the steps in (1) to spray the conditioner, stop watering, and apply nutrient solution. After applying nutrient solution for 6 days, start watering again to ensure soil moisture of 65-70%. Then, in mid-September, apply nutrient solution once more at a rate of 20g / plant. By March of the second year, seedlings with a height-to-diameter ratio of 70-100 can be transplanted for afforestation.

[0062] Comparative Example 5: Seedling cultivation methods for controlling the height-to-diameter ratio of camphor trees

[0063] In contrast to Example 4, the difference in Comparative Example 5 is that no conditioner was sprayed during seedling cultivation, as detailed below:

[0064] (1) Same as Example 4:

[0065] (2) Stop watering the seedlings in early July. Four days later, apply nutrient solution at a rate of 20g / plant. Three days after applying the nutrient solution, start watering again to maintain soil moisture at 50-55%.

[0066] (3) In early August, stop watering and apply nutrient solution again according to the method in step (1). After applying nutrient solution for 6 days, start watering again to ensure soil moisture of 65-70%. Then, in mid-September, apply nutrient solution once more at a rate of 20g / plant. By March of the second year, seedlings with a height-to-diameter ratio of 70-100 can be transplanted for afforestation.

[0067] Comparative Example 6: Seedling cultivation methods for controlling the height-to-diameter ratio of camphor trees

[0068] In contrast to Example 4, the difference lies in that watering was not stopped during seedling cultivation in Comparative Example 6, as detailed below:

[0069] (1) Same as Example 1;

[0070] (2) When the seedlings are cultivated to the beginning of July, the conditioner and water are mixed at a mass ratio of 1:100 to form a suspension. Then, spray the suspension at a rate of 15g / plant. Four days after spraying the conditioner, apply nutrient solution at a rate of 20g / plant and keep the soil moisture at 65-70%.

[0071] (3) In early August, follow the steps in (1) to spray the conditioner and apply the nutrient solution, and keep the soil moisture at 65-70%. Then, in mid-September, apply the nutrient solution again at a rate of 20g / plant. By March of the second year, the seedlings with a height-to-diameter ratio of 70-100 can be transplanted for afforestation.

[0072] Comparative Example 7: Seedling cultivation methods for controlling the height-to-diameter ratio of camphor trees

[0073] In contrast to Example 4, the difference is that in Comparative Example 7, no nutrient solution was applied during seedling cultivation; instead, plain water was applied, as detailed below:

[0074] (1) Same as Example 4;

[0075] (2) When the seedlings are cultivated to the beginning of July, the conditioner and water are mixed at a mass ratio of 1:100 to form a suspension. Then, spray the suspension at a rate of 15g / plant and stop watering. Four days after spraying the conditioner, apply clean water at a rate of 20g / plant. Three days after applying the clean water, start watering again to maintain the soil moisture at 50-55%.

[0076] (3) In early August, follow the steps in (1) to spray the conditioner, stop watering, and apply clean water. After applying clean water for 6 days, start watering again to ensure soil moisture of 65-70%. Then, in mid-September, apply clean water once more at a rate of 20g / plant. By March of the second year, seedlings with a height-to-diameter ratio of 70-100 can be transplanted for afforestation.

[0077] Comparative Example 8: Seedling cultivation methods for controlling the height-to-diameter ratio of camphor trees

[0078] In contrast to Example 4, the difference lies in that in Comparative Example 8, the watering and nutrient solution application were not stopped during seedling cultivation, as detailed below:

[0079] (1) Same as Example 4;

[0080] (2) When the seedlings are cultivated to the beginning of July, the conditioner and water are mixed at a mass ratio of 1:100 to form a suspension. Then, spray the suspension at a rate of 15g / plant and keep the soil moisture at 65-70%.

[0081] (3) In early August, follow the method in step (2) to spray the conditioner and perform the same management operations. By March of the second year, the seedlings with a height-to-diameter ratio of 70-100 can be transplanted for afforestation.

[0082] Comparative Example 9: Seedling cultivation methods for controlling the height-to-diameter ratio of camphor trees

[0083] In contrast to Example 4, the difference lies in the fact that in Comparative Example 9, the seedlings were cultivated using conventional methods to dwarf them, as detailed below:

[0084] (1) Same as Example 1;

[0085] (2) Spray the seedlings with a 100 mg / L chlormequat chloride solution until early July, and maintain the soil moisture at 65-70%;

[0086] (3) In early August, spray the chlormequat chloride solution according to the method in step (2) and carry out the same management. By March of the second year, the seedlings with a height-to-diameter ratio of 70-100 can be transplanted for afforestation.

[0087] Experiment 1: Conditioner Slow-Release Experiment

[0088] The drug (chlormequat chloride) release rates of the conditioners prepared in Example 1 and Comparative Examples 1-4 were measured on days 5 and 10 under conditions of 28°C and 2500 lx light intensity, respectively. The data are shown in Table 1.

[0089] Table 1

[0090]

[0091] Based on the data analysis in Table 1, we can conclude that:

[0092] (1) The drug release of the conditioner prepared in Example 1 on the 5th and 10th days under the conditions of temperature of 28℃ and light intensity of 2500lx were 43.6% and 62.7%, respectively. Compared with Comparative Examples 1-4, the drug release of the conditioner in Example 1 was slower and more stable, indicating that the conditioner prepared according to the method of the present invention has relatively stable performance. After encapsulating chlormequat chloride, it can slowly and continuously release the drug to act on the seedlings to regulate the plant height and ground diameter of the seedlings. It has a good regulatory effect on cultivating high-quality camphor seedlings with suitable height-to-diameter ratio.

[0093] (2) No dimethylglyoxal was added during the preparation of the conditioning agent in Comparative Example 1, and no 4-tert-butylcyclohexanol was added during the preparation of the conditioning agent in Comparative Example 2. The stability of soybean lecithin in Comparative Example 1 was poor, and the reactivity of soybean lecithin in Comparative Example 2 was strong. Due to the accelerated degradation of soybean lecithin under the influence of environmental factors such as light and oxygen in Comparative Examples 1 and 2, the encapsulation and fixation performance of chlormequat chloride was unstable, resulting in the rapid release of the drug. No vitamin C was added during the preparation of the conditioning agent in Comparative Example 4, and the oxidative degradation rate of the conditioning agent was faster, which reduced the fixation and protection effect of chlormequat chloride, resulting in the rapid release.

[0094] Experiment 2: Camphor Tree Seedling Cultivation Experiment

[0095] A camphor tree seedling cultivation experiment was conducted in Yunlong Town and Daguan Town, Liangping County. The experiment was divided into 11 groups: experimental group 1, control groups 1-9, and blank control group. The conditioners and seedling cultivation methods used in each group are as follows:

[0096] Experimental group 1: The seedling raising method of Example 1 and Example 4 were used;

[0097] Control groups 1-4: The conditioners used in comparative examples 1-4 and the seedling raising method used in example 4 were used respectively;

[0098] Control group 5: No conditioner was used; the seedling raising method of control group 5 was used.

[0099] Control groups 6-8: The conditioner prepared in Example 1 was used, and the seedling raising methods of Comparative Examples 6-8 were used respectively;

[0100] Control group 9: The seedling raising method used in control group 9 was the same as that used in control group 9, which involved spraying with a conventional chlormequat chloride solution.

[0101] Control group: No conditioner or nutrient solution was sprayed, and watering was stopped. Instead, the plant was cared for and cultivated using conventional methods, as detailed below:

[0102] Camphor trees are sown in mid-March and watered and fertilized according to conventional methods to maintain soil moisture at 65-70%. After the seedlings grow to a height of ≥5cm in May, they are thinned according to conventional methods. Seedlings with a height-to-diameter ratio of 70-100 can be transplanted for afforestation in March of the second year.

[0103] 2. Results: 20 camphor seedlings were cultivated in each group. In March of the second year, the seedling height and diameter at ground level were measured for each group. The height-to-diameter ratio was calculated based on the seedling height and diameter at ground level. The experiment was repeated three times, and the data are shown in Table 2.

[0104] Table 2

[0105]

[0106] According to the data analysis in Table 2, we can see that...

[0107] (1) The seedlings in experimental group 1 had high plant height and ground diameter, with a height-to-diameter ratio of 81.6. This indicates that the treatment of camphor seedlings according to the method of the present invention can effectively increase the ground diameter while ensuring the plant height of camphor seedlings. The resulting camphor seedlings have a moderate height-to-diameter ratio and are high-quality seedlings suitable for afforestation.

[0108] (2) The conditioner in control groups 1-4 had poor stability, which led to excessive release of chlormequat chloride. The seedlings absorbed a large amount of chlormequat chloride, which affected the growth of the seedlings. Although the height-diameter ratio of the seedlings obtained was more suitable for afforestation, their plant height and ground diameter were reduced to varying degrees compared with experimental group 1, and the quality of the seedlings was lower than that of the seedlings in experimental group 1.

[0109] (3) No conditioner was sprayed during seedling cultivation in control group 5, no drought stress was applied during seedling cultivation in control group 6, no nutrient solution was applied during seedling cultivation in control group 7, and no nutrient solution was applied and no drought stress was applied during seedling cultivation in control group 8. The diameter of the seedlings in control groups 5-8 was lower than that in experimental group 1. This indicates that by combining the conditioner with drought stress and nutrient solution according to the method of the present invention, the diameter of the seedlings can be effectively increased while ensuring that the height of the seedlings increases at a relatively slow rate. This can better control the height-to-diameter ratio of the seedlings and make them more suitable for afforestation.

[0110] (4) In the control group 9, the chlormequat chloride solution was sprayed directly. Due to the easy loss and ineffectiveness of the solution, the amount of effective components absorbed and utilized by the seedlings was small without increasing the number of sprays, the plant height decreased less, and the diameter of the seedlings did not increase significantly. The seedlings were in poorer condition than those in the experimental group 1. In contrast, the blank control group was cultivated directly according to conventional methods, and the plant height increased more rapidly while the diameter of the seedlings increased more slowly.

[0111] The above embodiments are only used to illustrate the technical solutions of the present invention and are not intended to limit it. Although the present invention has been described in detail with reference to preferred embodiments, those skilled in the art should understand that modifications or equivalent substitutions can be made to the technical solutions of the present invention without departing from the spirit and scope of the present invention, and all such modifications and substitutions should be covered within the scope of the claims of the present invention. Technical aspects, shapes, and structures not described in detail in this invention are all well-known technologies.

Claims

1. A seedling raising method for controlling the height-diameter ratio of Cinnamomum camphora for afforestation, characterized by, The method is as follows: (1) In mid-March, camphor is sowed, and routine management is carried out, and the soil moisture content is kept at 65-70% during the period; after the seedling grows to a height of ≥5 cm in May, the seedlings are thinned; (2) The seedlings are cultivated to early July, a conditioner is sprayed, and watering is stopped, after 3-5 days of spraying of the conditioner, nutrient solution is applied, after 3-4 days of application of the nutrient solution, watering is restarted to maintain the soil humidity at 50-55%; (3) In early August, the operations of spraying of the conditioner, stopping of watering and application of the nutrient solution are carried out again according to the method in step (1), after 5-7 days of application of the nutrient solution, watering is restarted to ensure the soil humidity of 65-70%, and then the nutrient solution is applied again in mid-September, and the seedlings with a height-diameter ratio of 70-100 are transplanted for afforestation in March of the second year; The conditioner in step (2) comprises the following raw materials: Chlormequat, soybean lecithin, Tween-80, chloroform, vitamin C, 4-tert-butylcyclohexanol, butanedione; The conditioner preparation method is as follows: A: soybean lecithin is dissolved in Tween-80, diluted with water, then butanedione is added, heated to 60-70℃ in a reaction kettle for 2-4h, after the reaction is completed, cooled to room temperature and left overnight, then 4-tert-butylcyclohexanol is added, heated to 60-70℃ for 1-2h, after the reaction is completed, naturally cooled to room temperature, then placed in a 4-8℃ environment for aging treatment for 12-24h, then dried to obtain pretreated soybean lecithin; B: the pretreated soybean lecithin is dissolved in chloroform, mixed with chlormequat for homogenization, after homogenization is completed, heated in hot water at 70-80℃ for 20-40min, then cooled to 40-50℃, then vitamin C is added, continuously stirred for 5-10min, then cooled to room temperature, then dried to obtain the conditioner; The nutrient solution preparation method is as follows: ammonium sulfate, potassium dihydrogen phosphate are mixed, then stirred and dissolved in water, then proline is added and uniformly mixed to obtain the nutrient solution.

2. The method of claim 1, wherein the height-diameter ratio of the Cinnamomum kaneirae is controlled. The mass ratio of soybean lecithin, Tween-80, butanedione and 4-tert-butylcyclohexanol in step A is (0.5-1):(1-1.5):(0.02-0.05):(0.01-0.02).

3. The method of claim 2, wherein the height-diameter ratio of the seedling is controlled. The mass ratio of pretreated soybean lecithin, chloroform, chlormequat and vitamin C in step B is (0.5-1):(0.8-1.2):(0.004-0.008):(0.005-0.01).

4. The method of claim 3, wherein the height-diameter ratio of the seedlings is controlled. The homogenization speed in step B is 1000-1500rpm, and the homogenization time is 3-5min.

5. The method of claim 4, wherein the height-diameter ratio of the seedling is controlled. The mass ratio of ammonium sulfate, potassium dihydrogen phosphate and proline is (20-30):(15-25):(2-3).

6. The method of claim 5, wherein the height-diameter ratio of the seedling is controlled. When the conditioner is sprayed, the conditioner and water are stirred and mixed in a mass ratio of 1:100 to form a suspension, and then sprayed, and the spraying amount is 10-20g / plant.

7. The method of claim 6, wherein the height-diameter ratio of the seedling is controlled to be 1.5 or less. The application amount of the nutrient solution is 15-30g / plant.

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