Composition containing 2, 4-D isooctyl ester, diethyl aminoethyl hexanoate and 24-epibrassinolide and application thereof

Abstract

The invention relates to a plant growth regulator, in particular to a composition containing 2, 4-D isooctyl ester, diethyl aminoethyl hexanoate and 24-epibrassinolide and application of the composition to weeding while promoting growth of a gramineous traditional Chinese medicinal material plant citronella, in general, 24-epibrassinolide cannot be mixed with a herbicide for use, and the composition can be used for weeding while promoting growth of the gramineous traditional Chinese medicinal material plant citronella. According to the composition disclosed by the invention, 2, 4-D isooctyl ester and 24-epibrassinolide can be applied at the same time, and excellent dual effects are shown by adjusting the dosage of 2, 4-D isooctyl ester and 24-epibrassinolide in different periods of the gramineous traditional Chinese medicinal material plant citronella; the composition in the specific proportion is sprayed in the 1-3 leaf period of the growth and development of the citronella, so that the growth of the citronella can be well promoted; when a large amount of weed acalypha australis appears in the citronella, the composition with the specific proportion is sprayed in the 4-5-leaf stage and the 2-3-leaf stage of the growth and development of the citronella, so that the growth of the acalypha australis can be remarkably inhibited.

Description

Technical Field

[0001] The invention relates to a plant growth regulator, in particular to a composition containing 2,4-D isooctyl ester, ammonium hexanoate and 24-epi-brassinolide and an application thereof in promoting the growth of gramineous plant citronella and achieving the removal of broadleaf weeds. Background Art

[0002] 2,4-D isooctyl ester is a chemical substance with the molecular formula C 16 H 22 Cl 2 O 3 , it is a colorless to light yellow liquid with a pungent odor at room temperature. It is soluble in many organic solvents such as alcohols, ethers and ketones, and can be co-soluble with some organic solvents in water. The compound has a low vapor pressure and a high flash point; 2,4-D isooctyl ester is mainly used as a herbicide, which can effectively control the growth of various herbaceous plants. It is widely used in agriculture, horticulture and forestry. It can also be used as a plant growth regulator and a spray for fruit trees.

[0003] The chemical formula of diethylaminoethyl ester is C 12 H 25 NO 2 , can increase the activity of plant peroxidase and nitrate reductase, increase the content of chlorophyll, accelerate photosynthesis, promote the division and elongation of plant cells, promote the development of root system, and regulate the balance of nutrients in the body. The original drug is a white flaky crystal, which is a white powder after crushing. It has no visible mechanical impurities and has a light fat aroma and greasy feeling. It is easily soluble in water and soluble in organic solvents such as ethanol, methanol, acetone, and chloroform; it is very stable when stored at room temperature, stable under neutral and acidic conditions, and easy to decompose under alkaline conditions. It can be compounded with a variety of elements and can also be used in combination with fungicides to enhance the disease resistance of plants and improve the bactericidal effect.

[0004] Brassinolide is a sterol compound that has a plant growth regulating effect and belongs to the sixth category of plant endogenous hormones. Most plant growth substances only have a regulatory effect on one or several physiological processes of plants. For example, gibberellins mainly promote the growth of plant organs, ethephon can promote plant maturity, chlormequat and mepiquat can only be used to inhibit sudden growth, while brassinolide can play a regulatory role in all growth and development stages of plants. This is the most important feature that distinguishes brassinolide from other plant endogenous hormones. In actual use, brassinolide has a certain suitable concentration. If the concentration is too high, it will not only cause waste, but also may inhibit crops to varying degrees.

[0005] Citronella is a grass herb with a stalk up to 2 meters high, a thick stem, and white wax powder attached to the nodes; the leaf sheath is hairless and does not curl outward, the leaves are pointed and narrow, with different green colors, and a refreshing lemon scent; the flowers are sparse, the tops are drooping, and small light green flowers bloom in summer. The flowering and fruiting period is summer, and it is rare to see flowering. "Guangdong Chinese Medicine" records that citronella: "It can dispel wind and reduce swelling. It is mainly used to treat dizziness, wind disease, gourd knee disease, and stop heart pain." It shows that it has the effects of dispelling wind, dredge meridians, warm the middle and stop pain, and stop diarrhea; the stems and leaves of citronella can be used to extract essential oils for making perfumes and soaps, and can also be eaten; the oil residue after oil extraction can be used to make paper, plastics, furfural, artificial cotton, etc., and has a wide range of applications, but there are currently no reports on plant regulators and herbicides that promote the growth of citronella.

[0006] With the development of diversified demand, a variety of brassinolide package products have gradually emerged in the market in recent years, such as brassinolide + pyraclostrobin, brassinolide + tebuconazole, brassinolide + potassium dihydrogen phosphate, brassinolide + 920, brassinolide + chloranil / paclobutrazol / mepiquat, etc. Brassinolide package products have the advantages of a wide spectrum of fungicides, synergistic enhancement, and strong rapidity. They are highly favored by the market and have greatly expanded the market space for brassinolide. However, these package products are all designed to enhance the effect of brassinolide in various growth and development stages of plants, thereby increasing yields, but they do not have a weed control effect. Once weeds appear, in order to avoid brassinolide reducing the weed control effect of herbicides, herbicides and plant growth regulators need to be used separately to increase the number of spraying times. Summary of the invention

[0007] In view of the problems existing in the prior art, the present invention provides a composition containing 2,4-D isooctyl ester, aminoethyl hexanoate and 24-epi-brassinolide. The composition can be sprayed at different growth and development stages of citronella to achieve different effects. Spraying the composition in a specific proportion at the 1-3 leaf stage of citronella growth and development can well promote the growth of citronella; when a large number of weeds Amaranthus tricolor appear in citronella, spraying the composition in a specific proportion at the 4-5 leaf stage of citronella growth and development and the 2-3 leaf stage of Amaranthus tricolor can significantly inhibit the growth of Amaranthus tricolor.

[0008] On the one hand, the present invention provides a composition containing 2,4-D isooctyl ester, diethylaminoethyl hexanoate and 24-epi-brassinolide, characterized in that the composition comprises effective ingredients 2,4-D isooctyl ester, diethylaminoethyl hexanoate and 24-epi-brassinolide, wherein the content of 2,4-D isooctyl ester in the composition is 0.005-0.01wt%, the content of diethylaminoethyl hexanoate in the composition is 0.5-1wt%, the content of 24-epi-brassinolide in the composition is 0.005-0.01wt%, the content of solvent in the composition is 40%-60%, and the content of emulsifier in the composition is 30%-50%, and the composition can significantly promote the growth and development of the Chinese medicinal plant citronella;

[0009] When the content of 2,4-D isooctyl ester in the composition is 10-20wt%, the content of diethylaminoethyl hexanoate is 0.1-0.5wt%, the content of 24-epi-brassinolide is 0.0005-0.001wt%, the content of the solvent is 40%-60%, and the content of the emulsifier is 30%-50%, the composition can significantly inhibit the growth of Amaranthus tricolor in citronella.

[0010] In some embodiments, the solvent is toluene or ethanol; and the emulsifier is sucrose ester or lauric acid.

[0011] In some embodiments, the solvent is ethanol and the emulsifier is lauric acid.

[0012] In some embodiments, the solvent is ethanol, and the emulsifier is sucrose ester.

[0013] In some embodiments, the solvent is toluene, and the emulsifier is sucrose ester.

[0014] In some embodiments, the solvent is toluene and the emulsifier is lauric acid.

[0015] In some embodiments, when the composition is mainly used to promote the growth of the Chinese medicinal plant lemongrass, it is composed of the following components in percentage by weight:

[0016]

[0017] In some embodiments, when the composition is mainly used to promote the growth of the Chinese medicinal plant lemongrass, it is composed of the following components in percentage by weight:

[0018]

[0019] In some embodiments, when the composition is mainly used for iron removal, it is composed of the following components in percentage by weight:

[0020]

[0021] In some embodiments, when the composition is mainly used to kill the weed Amaranthus chinensis, it is composed of the following components in percentage by weight:

[0022]

[0023] In another aspect, the present invention provides a method for preparing a composition containing 2,4-D isooctyl ester, diethylaminoethyl hexanoate and 24-epi-brassinolide, wherein the method comprises:

[0024] The solvent is first heated to 40-50°C, 24-epi-brassinolide is first added and stirred continuously until dissolved, then an emulsifier is slowly added to the solvent containing 24-epi-brassinolide, and while adding the emulsifier, aminoethyl hexanoate and 2,4-D isooctyl ester are added in sequence, the temperature is always maintained at 40-50°C, stirred until completely dissolved, and cooled to room temperature to obtain a composition containing 2,4-D isooctyl ester, aminoethyl hexanoate and 24-epi-brassinolide.

[0025] In some embodiments, the method comprises: first heating the ethanol solution to 40-50°C, first adding 24-epibrassinolide and stirring continuously until dissolved, then slowly adding lauric acid to the ethanol containing 24-epibrassinolide, and adding aminoethyl hexanoate and 2,4-D isooctyl ester in sequence while adding lauric acid, the temperature is always maintained at 40-50°C, stirring until completely dissolved, and cooling to room temperature to obtain a composition containing 2,4-D isooctyl ester, aminoethyl hexanoate and 24-epibrassinolide.

[0026] In some embodiments, the temperature is always maintained at 45-50°C.

[0027] On the other hand, the present invention provides an application of a composition containing 2,4-D isooctyl ester, ammonium hexanoate and 24-epi-brassinolide in promoting the growth of citronella, characterized in that 20-30 mL of the composition containing 0.005-0.01 wt % 2,4-D isooctyl ester, 0.5-1 wt % ammonium hexanoate and 0.005-0.01 wt % 24-epi-brassinolide is taken, diluted with 25-30 kg of water, and sprayed on the citronella during the 1-3 leaf stage of its growth and development, spraying 2-3 times, with an interval of 7-10 days between each spraying.

[0028] On the other hand, the present invention provides an application of a composition containing 2,4-D isooctyl ester, aminoethyl hexanoate and 24-epi-brassinolide in removing Amaranthus trichoderma, characterized in that: 20-30 mL of the composition containing 10-20 wt% 2,4-D isooctyl ester, 0.1-0.5 wt% aminoethyl hexanoate and 0.0005-0.001 wt% 24-epi-brassinolide is taken, diluted with 25-30 kg of water, and sprayed on the weeds when the lemongrass is in the 4-5 leaf stage of growth and development and the Amaranthus trichoderma is in the 2-3 leaf stage, spraying is performed 2-3 times, and each spraying time needs to be 7-10 days apart. DETAILED DESCRIPTION

[0029] Unless defined otherwise, all technical and scientific terms used herein have the same meaning as commonly understood by one of ordinary skill in the art to which this invention belongs.

[0030] All publications, patent applications, patents, and other references mentioned herein are incorporated herein by reference in their entirety. In the event of a conflict, the present specification (including definitions) shall prevail. In addition, the materials, methods, and examples described herein are illustrative only and are not intended to be limiting.

[0031] The terms "about" and "approximately" when used in conjunction with a numerical variable generally mean that the value of the variable and all values ​​of the variable are within measurement or experimental error (e.g., 95% confidence interval for the mean) or within a wider range of the specified value (e.g., ±5% or ±10%).

[0032] The term "comprise" or its variations such as "contains", "has", "includes" means including the stated steps or elements but not excluding any other steps or elements. "Consisting of" means not excluding steps or elements not listed. "Consisting essentially of" means not excluding steps or elements that do not substantially affect the basic and novel features of the invention being protected. The term "comprising" specific steps or elements and its variations also include "consisting of" and "consisting essentially of" specific steps or elements.

[0033] When a numerical range is mentioned, it should be deemed to specifically disclose the specific values ​​of its upper and lower limits, as well as all intermediate ranges included therein, such as the intermediate range between its upper or lower limit and any intermediate value, or the intermediate range between any two intermediate values ​​thereof. In addition, any intermediate range, subrange and all individual values ​​described in the numerical range can be excluded from the numerical range described.

[0034] The term "and / or" should be understood to refer to any one element or any combination of several elements connected by the term.

[0035] In some embodiments, the content of 2,4-D isooctyl ester is 0.005-0.01wt%, for example, the content of 2,4-D isooctyl ester can be 0.005wt%, 0.006wt%, 0.007wt%, 0.008wt%, 0.009wt%, 0.01wt%; the content of aminoethyl hexanoate is 0.5%-1%, for example, the content of aminoethyl hexanoate can be 0.5%, 0.6%, 0.7%, 0.8%, 0.9%, 1%; the content of 24-epibrassinolide is 0.005-0.01wt%, for example, the content of 24-epibrassinolide can be 0.005%, 0.006%, 0.007%, 0.008%, 0.009%, 0.01%.

[0036] In some embodiments, the content of 2,4-D isooctyl ester is 10-20wt%, for example, the content of 2,4-D isooctyl ester can be 10wt%, 12wt%, 14wt%, 16wt%, 18wt%, 20wt%; the content of aminoethyl hexanoate is 0.1%-0.5%, for example, the content of aminoethyl hexanoate can be 0.1%, 0.2%, 0.3%, 0.4%, 0.5%; the content of 24-epibrassinolide is 0.0005-0.001wt%, for example, the content of 24-epibrassinolide can be 0.0005%, 0.0006%, 0.0007%, 0.0008%, 0.0009%, 0.001%.

[0037] In some embodiments, when the composition is mainly used to promote the growth of the Chinese medicinal plant lemongrass, it is composed of the following components in percentage by weight:

[0038]

[0039] In some embodiments, when the composition is mainly based on the iron-removing effect of Amaranthus, it is composed of the following components in percentage by weight:

[0040]

[0041] In some embodiments, 20 mL of a composition containing 0.005-0.01 wt % 2,4-D isooctyl ester, 0.5-1 wt % ammonium hexanoate and 0.005-0.01 wt % 2,4-epi-brassinolide is taken, 25 kg of water is added for dilution, and the composition is sprayed on the citronella twice during the 1-3 leaf stage of its growth and development, with an interval of 7-10 days between the two sprayings.

[0042] In some embodiments, 20 mL of a composition containing 0.005 wt % 2,4-D isooctyl ester, 0.5 wt % ammonium hexanoate and 0.005 wt % 2,4-epi-brassinolide is taken, diluted with 25 kg, and sprayed on the citronella twice during the 1-3 leaf stage of its growth and development, with an interval of 7-10 days between the two sprayings.

[0043] In some embodiments, 20 mL of a composition containing 0.008 wt % 2,4-D isooctyl ester, 0.8 wt % ammonium hexanoate and 0.006 wt % 2,4-epi-brassinolide is taken, diluted with 25 kg of water, and sprayed on the citronella twice during the 1-3 leaf stage of its growth and development, with an interval of 7-10 days between the two sprayings.

[0044] In some embodiments, 20 mL of a composition containing 0.01 wt % 2,4-D isooctyl ester, 1 wt % ammonium hexanoate and 0.01 wt % 2,4-epi-brassinolide is taken, diluted with 25 kg of water, and sprayed on the citronella twice during the 1-3 leaf stage of its growth and development, with an interval of 7-10 days between the two sprayings.

[0045] In some embodiments, 25 mL of a composition containing 0.005-0.01 wt % 2,4-D isooctyl ester, 0.5-1 wt % ammonium hexanoate and 0.005-0.01 wt % 2,4-epi-brassinolide is taken, 25 kg of water is added for dilution, and the composition is sprayed on the citronella twice during the 1-3 leaf stage of its growth and development, with an interval of 7-10 days between the two sprayings.

[0046] In some embodiments, 30 mL of a composition containing 0.005-0.01 wt % 2,4-D isooctyl ester, 0.5-1 wt % ammonium hexanoate and 0.005-0.01 wt % 2,4-epi-brassinolide is taken, 25 kg of water is added for dilution, and the composition is sprayed on the citronella twice during the 1-3 leaf stage of its growth and development, with an interval of 7-10 days between the two sprayings.

[0047] In some embodiments, 30 mL of a composition containing 10-20 wt % 2,4-D isooctyl ester, 0.1-0.5 wt % ammonium hexanoate and 0.0005-0.001 wt % 2,4-epi-brassinolide is taken, 30 kg of water is added for dilution, and the composition is sprayed on Amaranthus tricolor twice when Lemongrass is in the 4-5 leaf stage of its growth and development and Amaranthus tricolor is in the 2-3 leaf stage of its growth and development, with an interval of 7-10 days between the two sprayings.

[0048] In some embodiments, 30 mL of a composition containing 10 wt % 2,4-D isooctyl ester, 0.1 wt % ammonium hexanoate and 0.0005 wt % 2,4-epicrassinolide is taken, 30 kg of water is added for dilution, and the composition is sprayed on Amaranthus tricolor twice when Lemongrass is in the 4-5 leaf stage of its growth and development and Amaranthus tricolor is in the 2-3 leaf stage of its growth and development, with an interval of 10 days between the two sprayings.

[0049] In some embodiments, 30 mL of a composition containing 15 wt % 2,4-D isooctyl ester, 0.3 wt % ammonium hexanoate and 0.0005 wt % 2,4-epicrassinolide is taken, 30 kg of water is added for dilution, and the composition is sprayed on Amaranthus tricolor twice when Lemongrass is in the 4-5 leaf stage of growth and development and Amaranthus tricolor is in the 2-3 leaf stage, with an interval of 10 days between the two sprayings.

[0050] In some embodiments, 20 mL of a composition containing 20 wt % 2,4-D isooctyl ester, 0.5 wt % ammonium hexanoate and 0.001 wt % 2,4-epi-brassinolide is taken, 30 kg of water is added for dilution, and the composition is sprayed on Amaranthus tricolor twice when Lemongrass is in the 4-5 leaf stage of growth and development and Amaranthus tricolor is in the 2-3 leaf stage, with an interval of 7 days between the two sprayings.

[0051] In some embodiments, 25 mL of a composition containing 10-20 wt % 2,4-D isooctyl ester, 0.1-0.5 wt % ammonium hexanoate and 0.0005-0.001 wt % 2,4-epi-brassinolide is diluted with 30 kg of water and sprayed on Amaranthus tricolor twice when Lemongrass is in the 4-5 leaf stage and Amaranthus tricolor is in the 2-3 leaf stage, with an interval of 8 days between the two sprayings.

[0052] In some embodiments, 30 mL of a composition containing 10-20 wt % 2,4-D isooctyl ester, 0.1-0.5 wt % ammonium hexanoate and 0.0005-0.001 wt % 2,4-epicrassinolide is taken, 30 kg of water is added for dilution, and the composition is sprayed on Amaranthus tricolor twice when Lemongrass is in the 4-5 leaf stage of its growth and development and Amaranthus tricolor is in the 2-3 leaf stage of its growth and development, with an interval of 10 days between the two sprayings.

[0053] The present invention is further described by the following examples, which should not be construed as limiting the present invention.

[0054] Unless otherwise specified, all reagents used in the following examples are commercially available products.

[0055] Example 1

[0056] Components and contents: 2,4-D isooctyl ester 0.005wt%, ammonium ethyl ester 0.5wt%, 24-epi-brassinolide 0.005wt%, ethanol 57.50wt%, lauric acid 42wt%. The above components are weighed, dissolved and mixed by weight to prepare a composition, and the above raw materials are all commercially available qualified products.

[0057] Preparation method: first heat the ethanol solution to 40°C, first add 24-epibrassinolide and stir continuously until dissolved, then slowly add lauric acid to the ethanol containing 24-epibrassinolide, and add aminoethyl hexanoate and 2,4-D isooctyl ester in sequence while adding lauric acid, keep the temperature at 40°C, stir until completely dissolved, and cool to room temperature to obtain a composition containing 2,4-D isooctyl ester, aminoethyl hexanoate and 24-epibrassinolide.

[0058] Example 2

[0059] Components and contents: 2,4-D isooctyl ester 0.005wt%, ammonium ethyl ester 0.5wt%, 24-epi-brassinolide 0.008wt%, ethanol 60.0wt%, lauric acid 39.5wt%. The above components are weighed, dissolved and mixed by weight to prepare the composition, and the above raw materials are all commercially available qualified products.

[0060] Preparation method: first heat the ethanol solution to 45°C, first add 24-epibrassinolide and stir continuously until dissolved, then slowly add lauric acid to the ethanol containing 24-epibrassinolide, and add aminoethyl hexanoate and 2,4-D isooctyl ester in sequence while adding lauric acid, keep the temperature at 45°C, stir until completely dissolved, and cool to room temperature to obtain a composition containing 2,4-D isooctyl ester, aminoethyl hexanoate and 24-epibrassinolide.

[0061] Example 3-38

[0062] Components and contents: The components and contents of Examples 3-38 are shown in Table 1, wherein the compositions of Examples 1-20 are used to promote the growth of lemongrass; and the compositions of Examples 21-38 are used to remove the weed Amaranthus chinensis from lemongrass:

[0063] Preparation method: Same as Examples 1 and 2, wherein the solvent used in Examples 3 to 7 is ethanol, and the emulsifier is lauric acid; the solvent used in Examples 8 to 17 is toluene, and the emulsifier is lauric acid; the solvent used in Examples 18 to 20 is ethanol, and the emulsifier is sucrose ester; the solvent used in Examples 21 to 30 is toluene, and the emulsifier is sucrose ester; the solvent used in Examples 31 to 34 is ethanol, and the emulsifier is sucrose ester; the solvent used in Examples 35 to 38 is ethanol, and the emulsifier is lauric acid.

[0064] Table 1: Content of each component in Examples 1-38

[0065]

[0066]

[0067] Example 39: Experimental test of the effects of Examples 1-20

[0068] The compositions obtained in Examples 1-20 respectively containing 0.005-0.01wt% 2,4-D isooctyl ester, 0.5-1wt% ammonium hexanoate and 0.005-0.01wt% 24-epi-brassinolide were diluted, specifically in the following manner: 20-30mL of the composition containing 0.005-0.01wt% 2,4-D isooctyl ester, 0.5-1wt% ammonium hexanoate and 0.005-0.01wt% 24-epi-brassinolide was taken, 25-30kg of water was added for dilution, and the composition was sprayed on the citronella twice during the 1-3 leaf stage of its growth and development, with an interval of 7-10 days between the two sprayings. The following Table 2 shows the root length and stem diameter of the citronella plants one month after the first application of the composition obtained in Examples 1-20, and the control group in the table was sprayed with the same amount of water:

[0069] Table 2: Root length and stem diameter of lemongrass plants after application of the composition obtained in Examples 1-20

[0070]

[0071]

[0072] Example 40: Experimental test of the effects of Examples 21-38

[0073] The composition containing 10-20wt% 2,4-D isooctyl ester, 0.1-0.5wt% ammonium hexanoate and 0.0005-0.001wt% 24-epi-brassinolide obtained in Examples 21-38 was diluted in the following manner: 20-30mL of the composition containing 2,4-D isooctyl ester, ammonium hexanoate and 24-epi-brassinolide respectively obtained in Examples 21-38 were taken, diluted with 30kg of water, and sprayed on the area to be treated in groups according to the following table, wherein the area to be treated is a citronella area containing about 15-20 Amaranthus scabrae, and each area is about 5m 2 , spray the lemongrass twice when it is in the 4-5 leaf stage and the Amaranthus tricolor when it is in the 2-3 leaf stage. The interval between the two sprayings is 10 days. Check the weed control effect 20 days after the second spraying.

[0074] Table 3: Test results of herbicidal effects of application examples 21-38

[0075]

[0076]

[0077]

[0078] It can be concluded from Table 2 and Table 3 that when the content of the active ingredient 2,4-D isooctyl ester is 0.005-0.01wt%, the content of aminoethyl hexanoate is 0.5-1wt%, and the content of 24-epi-brassinolide is 0.005-0.01wt%, the composition is sprayed on the citronella twice during the 1-3 leaf stage of its growth and development, with an interval of 7-10 days between the two sprayings, which can significantly promote the growth of the Chinese medicinal plant citronella, which is specifically manifested in the citronella. The stalk height and stem thickness of lemongrass are increased; when the content of the effective ingredient 2,4-D isooctyl ester is 10-20wt%, the content of aminoethyl hexanoate is 0.1-0.5wt%, and the content of 24-epi-brassinolide is 0.0005-0.001wt%, the composition is sprayed on the Amaranthus tricolor twice when the citronella is in the 4-5 leaf stage of its growth and development and the Amaranthus tricolor is in the 2-3 leaf stage of its growth and development, with an interval of 7-10 days between the two sprayings, and has a significant effect on inhibiting the growth of the Amaranthus tricolor.

[0079] The implementation of the present invention is not limited to the above-mentioned embodiments. Without departing from the spirit and scope of the present invention, ordinary technicians in this field can make various changes and improvements to the present invention in form and detail, and these are considered to fall within the protection scope of the present invention.

Claims

1. A composition containing 2,4-D isooctyl ester, diethylaminoethyl hexanoate and 24-epi-brassinolide, characterized in that: The active ingredients are 2,4-D isooctyl ester, aminoethyl hexanoate and 24-epi-brassinolide, among which: When the content of 2,4-D isooctyl ester in the composition is 0.005-0.01wt%, the content of aminoethyl hexanoate is 0.5-1.0wt%, the content of 24-epi-brassinolide is 0.005-0.01wt%, the content of solvent is 40%-60%, and the content of emulsifier is 30%-50%, the composition can significantly promote the growth and development of the Chinese medicinal plant citronella; When the content of 2,4-D isooctyl ester in the composition is 10-20wt%, the content of diethylaminoethyl hexanoate is 0.1-0.5wt%, the content of 24-epi-brassinolide is 0.0005-0.001wt%, the content of the solvent is 40%-60%, and the content of the emulsifier is 30%-50%, the composition can significantly inhibit the growth of the weed Amaranthus chinensis in lemongrass.

2. The composition according to claim 1, characterized in that: The solvent is toluene or ethanol; the emulsifier is sucrose ester or lauric acid, preferably the solvent is ethanol, and preferably the emulsifier is sucrose ester.

3. The composition according to claim 1, characterized in that: When the composition is mainly used to promote the growth of the Chinese medicinal plant lemongrass, it is composed of the following components in percentage by weight:

4. The composition according to claim 1, characterized in that: When the composition is mainly used to remove weeds from Amaranthus chinensis, it is composed of the following components in percentage by weight:

5. A method for preparing the composition according to any one of claims 1 to 4, characterized in that: The solvent is first heated to 40-50°C, 24-epi-brassinolide is first added and stirred continuously until dissolved, then an emulsifier is slowly added to the solvent containing 24-epi-brassinolide, and while adding the emulsifier, aminoethyl hexanoate and 2,4-D isooctyl ester are added in sequence, the temperature is always maintained at 40-50°C, stirred until completely dissolved, and cooled to room temperature to obtain a composition containing 2,4-D isooctyl ester, aminoethyl hexanoate and 24-epi-brassinolide.

6. The preparation method according to claim 5, characterized in that: The temperature was maintained at 45-50°C throughout.

7. Use of the composition containing 2,4-D isooctyl ester, ampicillin and 24-epi-brassinolide as claimed in claim 3 in promoting the growth of citronella.

8. Use of the composition containing 2,4-D isooctyl ester, ampicillin and 24-epi-brassinolide as claimed in claim 4 in killing the weed Amaranthus tricolor.

9. The use of the composition according to claim 7 or 8, characterized in that: Take 20-30 mL of the composition containing 2,4-D isooctyl ester, aminoethyl hexanoate and 24-epi-brassinolide, add 25-30 kg of water for dilution, and spray it on the citronella or amaranth.

10. The use of the composition according to claim 9, characterized in that: Spray the composition containing 2,4-D isooctyl ester, aminoethyl hexanoate and 24-epi-brassinolide as claimed in claim 3 when the lemongrass is in the 1-3 leaf stage of growth and development; spray the composition containing 2,4-D isooctyl ester, aminoethyl hexanoate and 24-epi-brassinolide as claimed in claim 4 when the lemongrass is in the 4-5 leaf stage of growth and development and the amaranth is in the 2-3 leaf stage of growth and development, and spray the lemongrass and / or amaranth 2-3 times, with an interval of 7-10 days between each spraying.

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