Plant growth promoter and composition for promoting plant growth comprising same

Abstract

The present invention relates to a plant growth promoter containing a polyhydroxyalkanoate (PHA) and a composition for promoting plant growth, the composition comprising the plant growth promoter. The plant growth promoter has excellent biodegradability, biocompatibility and the like, and thus is safe and environmentally friendly, and can effectively promote plant growth.

Description

Technical Field

[0001] The present disclosure relates to a plant growth promoter comprising a biodegradable polymer and promoting plant growth, and a composition for promoting plant growth comprising the plant growth promoter. Background Art

[0002] Plants are continuously exposed to biotic stresses caused by other organisms (such as diseases and pests), as well as abiotic stresses caused by physical or chemical environmental changes (such as heat, drought, and salinity). Such stresses remove nutrients from the soil or cause plant roots to lose the ability to absorb necessary substances, resulting in reduced plant growth and decreased productivity. Therefore, plant growth promoters that help plants recover from stress by replenishing elements necessary for plant growth are gaining attention.

[0003] These plant growth promoters are substances that help plant growth and metabolism. They serve as food for soil microorganisms, improve nutrient absorption, increase chlorophyll efficiency and yield, antioxidant effects, metabolism and soil water retention capacity, thereby promoting new growth, root development and cell expansion of plants. Currently, commercially available plant growth promoter products contain plant hormones such as auxin, cytokinin and gibberellin, humic acid, seaweed extracts, etc. as their main ingredients.

[0004] However, since these plant growth promoter products contain various chemical substances in addition to the above main ingredients, it has not yet been clearly confirmed whether the plants to which the plant growth promoters are applied are harmless to the human body. Some people also point out that there are environmental problems such as soil pollution.

[0005] Therefore, there is a need to develop a plant growth promoter that is safe and environmentally friendly and can help the growth and metabolism of plants, thereby promoting their growth.

[0006] [Prior art literature]

[0007] [Patent Document]

[0008] (Patent Document 1) Korean Early Publication Patent Publication No. 2015-0011623. Summary of the invention

[0009] Technical issues

[0010] The purpose of the present invention is to provide a plant growth promoter that can promote plant growth and is safe and environmentally friendly.

[0011] Furthermore, an object of the present disclosure is to provide a composition for promoting plant growth, which comprises the plant growth promoter.

[0012] Solution to the problem

[0013] According to one aspect of the present disclosure to solve the above-mentioned problems, a plant growth promoter including polyhydroxyalkanoate (PHA) is provided.

[0014] In an embodiment, the polyhydroxyalkanoate (PHA) may be included in an amount of 1 to 100 wt % based on the total weight of the plant growth promoter.

[0015] In another embodiment, the polyhydroxyalkanoate (PHA) may comprise repeating units derived from at least one selected from the group consisting of 3-hydroxybutyrate (3HB), 4-hydroxybutyrate (4HB), 3-hydroxypropionate (3HP), 3-hydroxyhexanoate (3HH), 3-hydroxyvalerate (3HV), 4-hydroxyvalerate (4HV), 5-hydroxyvalerate (5HV) and 6-hydroxyhexanoate (6HH).

[0016] In another embodiment, the polyhydroxyalkanoate (PHA) may comprise repeating units derived from 4-hydroxybutyrate (4HB).

[0017] In another embodiment, the content of the repeating unit derived from 4-hydroxybutyrate (4HB) may be 1 to 80 mol % based on the total moles of the polyhydroxyalkanoate (PHA).

[0018] In another embodiment, the polyhydroxyalkanoate (PHA) may be a poly(3-hydroxybutyrate-co-4-hydroxybutyrate) copolymer comprising repeating units derived from 3-hydroxybutyrate (3HB) and repeating units derived from 4-hydroxybutyrate (4HB).

[0019] In another embodiment, the molar ratio of the repeating units derived from 3-hydroxybutyrate (3HB) to the repeating units derived from 4-hydroxybutyrate (4HB) may be 20:80 to 99:1.

[0020] In another embodiment, the polyhydroxyalkanoate (PHA) may have a molecular weight of 200,000 to 1,000,000 g / mole.

[0021] In another embodiment, the plant growth promoter may further comprise a biodegradable polymer.

[0022] In another embodiment, the biodegradable polymer may include at least one selected from the group consisting of polylactic acid (PLA), polyvinyl alcohol (PVOH), ethylene-vinyl alcohol copolymer (EVOH), polybutylene adipate-terephthalate copolymer (PBAT), polybutylene succinate (PBS), polycaprolactone (PCL) and thermoplastic starch (TPS).

[0023] In another embodiment, the biodegradable polymer may be polylactic acid (PLA).

[0024] In another embodiment, the polyhydroxyalkanoate (PHA) may be included in an amount of 20 to 70 wt %, and the biodegradable polymer may be included in an amount of 30 to 80 wt %, based on the total weight of the plant growth promoter.

[0025] Meanwhile, according to another aspect of the present disclosure, a composition for promoting plant growth is provided, which comprises a plant growth promoter, wherein the plant growth promoter comprises polyhydroxyalkanoate (PHA).

[0026] In an embodiment, the plant growth promoter may be included in an amount of 0.001 to 10 wt % based on the total weight of the composition for promoting plant growth.

[0027] Advantageous Effects of the Invention

[0028] The plant growth promoter according to the present disclosure is harmless when applied to plants and soil because it contains polyhydroxyalkanoate (PHA) with excellent biodegradability and biocompatibility. It decomposes into organic matter in the soil, thereby increasing the activity of microorganisms in the soil and causing them to proliferate, which makes it possible to promote root growth and improve the nutrient absorption rate of plants.

[0029] Therefore, the present disclosure can promote plant growth while solving the safety and environmental pollution problems caused by conventional plant growth promoters, thereby helping to improve plant productivity. BRIEF DESCRIPTION OF THE DRAWINGS

[0030] Figure 1 The results of confirming the germination levels (states) of barley and lettuce according to Test Example 2 described in the present disclosure are shown.

[0031] Figure 2 The results of the confirmation of the germination rate of corn according to Test Example 4 described in the present disclosure are shown.

[0032] Figure 3 The results of confirming the cucumber germination rate according to Test Example 4 described in the present disclosure are shown.

[0033] Figure 4 The results of measuring the fresh weight of corn roots according to Test Example 5 described in the present disclosure are shown.

[0034] Figure 5 The results of measuring the fresh weight of cucumber roots according to Test Example 6 described in the present disclosure are shown. DETAILED DESCRIPTION

[0035] Hereinafter, the present disclosure will be described with reference to the embodiments. Herein, the present disclosure is not limited to the disclosure given below, and various forms of deformation are possible as long as the core of the present invention is not changed.

[0036] In this specification, the term "comprising" is intended to specify specific features, regions, steps, processes, elements and / or components. It does not exclude the existence or addition of any other features, regions, steps, processes, elements and / or components, unless explicitly stated to the contrary.

[0037] Unless otherwise indicated, all numbers and expressions relating to quantities of components, reaction conditions, and so forth used herein are to be understood as modified by the term "about."

[0038] Plant growth promoter

[0039] The plant growth promoter according to the embodiment of the present disclosure includes polyhydroxyalkanoate (PHA) having excellent biodegradability and biocompatibility.

[0040] Polyhydroxyalkanoates (PHA) have excellent biodegradability measured according to ISO 14855 standard (which is the ratio of organic carbon of the test substance that has been converted into inorganic carbon in the form of gaseous CO2). Therefore, when applied to soil, it is biodegradable and can activate microorganisms in the soil. In addition, polyhydroxyalkanoates (PHA) have low immunogenicity and therefore have excellent biocompatibility. Therefore, when a plant growth promoter comprising such polyhydroxyalkanoates (PHA) according to the present disclosure is applied to plants, it can greatly help the growth and metabolism of plants, thereby promoting the growth of plants. When the plants thus obtained are eaten by humans, they may be harmless to the human body.

[0041] Specifically, the biodegradability of the polyhydroxyalkanoate (PHA) measured according to ISO 14855 standard can be 50% or more, 60% or more, 70% or more, or 80% or more (e.g., 50 to 100%, 50 to 95%, 50 to 90%, 55 to 90%, 60 to 85%, or 70 to 85%).

[0042] The polyhydroxyalkanoate (PHA) may include repeating units derived from at least one (at least one monomer) selected from the group consisting of 3-hydroxybutyrate (3HB), 4-hydroxybutyrate (4HB), 3-hydroxypropionate (3HP), 3-hydroxyhexanoate (3HH), 3-hydroxyvalerate (3HV), 4-hydroxyvalerate (4HV), 5-hydroxyvalerate (5HV) and 6-hydroxyhexanoate (6HH).

[0043] Specifically, the polyhydroxyalkanoate (PHA) may include a repeating unit derived from 4-hydroxybutyrate (4HB) (4HB repeating unit). Since the polyhydroxyalkanoate (PHA) includes the 4HB repeating unit, the biodegradability and growth promoting ability of the plant growth promoter may be enhanced.

[0044] The content of the 4HB repeating unit may be 1 to 80 mol%, specifically, 1 to 75 mol%, 2 to 70 mol%, 2 to 65 mol%, 2 to 50 mol%, 3 to 60 mol%, 4 to 55 mol%, 5 to 50 mol%, 6 to 45 mol%, 8 to 40 mol%, 9 to 35 mol%, or 10 to 33 mol%, based on the total moles of the polyhydroxyalkanoate (PHA) (the total moles of the repeating units constituting the PHA). When the content of the 4HB repeating unit is within the above range, the biodegradability and growth promoting ability of the plant growth promoter can be improved.

[0045] Specifically, the polyhydroxyalkanoate (PHA) may be a poly(3-hydroxybutyrate-co-4-hydroxybutyrate) copolymer. Thus, the biodegradability, biocompatibility and growth promoting ability of the plant growth promoter may be maximized.

[0046] The molar ratio of the repeating unit derived from 3-hydroxybutyrate (3HB) (3HB repeating unit) and the repeating unit derived from 4-hydroxybutyrate (4HB) (4HB repeating unit) contained in the poly (3-hydroxybutyrate-co-4-hydroxybutyrate) copolymer (molar ratio of 3HB repeating unit to 4HB repeating unit) is not particularly limited, and specifically can be 20:80 to 99:1, 25:75 to 99:1, 35:65 to 99:1, 40:60 to 95:5, 45:55 to 95:5, 50:50 to 95:5, 55:45 to 95:5, 60:40 to 90:10 or 65:35 to 90:10. When the molar ratio is within the above range, the biodegradability and growth promoting ability of the plant growth promoter can be improved.

[0047] At the same time, the crystallinity of polyhydroxyalkanoates (PHA) can be adjusted according to the content of 4HB repeating units. It can be divided into semi-crystalline PHA (scPHA) and amorphous PHA (aPHA).

[0048] Specifically, based on the total moles of polyhydroxyalkanoate (PHA), the content of 4HB repeating units in scPHA may be 0.1 to 30 mol%, 1 to 25 mol%, 3 to 23 mol%, 5 to 20 mol%, 7 to 15 mol%, 8 to 13 mol%, or 9 to 11 mol%. Specifically, based on the total moles of polyhydroxyalkanoate (PHA), the content of 4HB repeating units in aPHA may be 20 to 50 mol%, 23 to 45 mol%, 25 to 43 mol%, 26 to 40 mol%, 29 to 37 mol%, 31 to 35 mol%, or 31 to 34 mol%.

[0049] The polyhydroxyalkanoate (PHA) may consist of scPHA alone, aPHA alone, or a mixture thereof.

[0050] The crystallinity of the polyhydroxyalkanoate (PHA) is not particularly limited, but the crystallinity measured using a differential scanning calorimeter (DSC) may be 90% or less, 85% or less, 80% or less, 75% or less, or 70% or less (e.g., 30 to 90%, 40 to 90%, 50 to 85%, or 60 to 80%).

[0051] The crystallization temperature (T) of polyhydroxyalkanoates (PHA) c ) is not particularly limited, but specifically may be 60 to 120° C., 65 to 120° C., 70 to 115° C., 80 to 115° C., 85 to 110° C., 90 to 110° C., or 90 to 105° C. In addition, the crystallization temperature (T c ) may not be determinable.

[0052] The melting temperature (T m ) is not particularly limited, but specifically may be 90 to 180° C., 95 to 175° C., 100 to 170° C., 110 to 160° C., 115 to 150° C., 120 to 140° C., or 125 to 135° C. In addition, the melting temperature (T m ) may not be determinable.

[0053] The glass transition temperature (T g ) is not particularly limited, but specifically may be -45 to 80°C, -40 to 60°C, -35 to 50°C, -25 to 25°C, -20 to 20°C, -20 to 15°C, -15 to 10°C or -10 to 0°C. In addition, the glass transition temperature (T g ) may not be determinable.

[0054] The molecular weight of the polyhydroxyalkanoate (PHA) (e.g., poly(3-hydroxybutyrate-co-4-hydroxybutyrate) copolymer) is not particularly limited, but specifically may be 200,000 to 1,000,000 g / mol, 230,000 to 980,000 g / mol, 250,000 to 950,000 g / mol, 280,000 to 930,000 g / mol, 300,000 to 900,000 g / mole, 320,000 to 900,000 g / mole, 340,000 to 880,000 g / mole, 350,000 to 850,000 g / mole, 380,000 to 850,000 g / mole, 400,000 to 830,000 g / mole or 400,000 to 800,000 g / mole. When the molecular weight of the polyhydroxyalkanoate (PHA) is within the above range, the growth promoting effect of the plant can be enhanced.

[0055] Based on the total weight of the plant growth promoter, the content of the polyhydroxyalkanoate (PHA) can be 1 to 100 weight %, specifically, 10 to 100 weight %, 15 to 100 weight %, 20 to 100 weight %, 10 to 95 weight %, 13 to 93 weight %, 15 to 90 weight %, 20 to 90 weight %, 22 to 88 weight %, 25 to 85 weight %, 25 to 80 weight %, 28 to 78 weight % or 30 to 75 weight %. When the content of the polyhydroxyalkanoate (PHA) is within the above range, the biodegradability, biocompatibility and growth promotion ability of the plant growth promoter can be improved.

[0056] Meanwhile, the plant growth promoter according to the present disclosure may be a powder or liquid formulation. Specifically, the plant growth promoter according to the present disclosure may have a powder formulation consisting of particles of polyhydroxyalkanoate (PHA) itself or a dispersed formulation in which polyhydroxyalkanoate (PHA) particles are dispersed in a solvent.

[0057] In addition to polyhydroxyalkanoate (PHA), the plant growth promoter according to the present disclosure may also include a well-known biodegradable polymer (BP). Specifically, the biodegradable polymer (BP) may be at least one selected from the group consisting of polylactic acid (PLA), polyvinyl alcohol (PVOH), ethylene-vinyl alcohol copolymer (EVOH), polybutylene adipate-terephthalate copolymer (PBAT), polybutylene succinate (PBS), polycaprolactone (PCL) and thermoplastic starch (TPS). Preferably, it may be polylactic acid (PLA).

[0058] When the plant growth promoter according to the present disclosure contains polyhydroxyalkanoate (PHA) and a biodegradable polymer (BP), there is no particular limitation on their content, but based on the total weight of the plant growth promoter, 20 to 70 wt % (specifically, 25 to 70 wt %, 25 to 65 wt %, 28 to 60 wt %, 30 to 55 wt % or 30 to 50 wt %) of polyhydroxyalkanoate (PHA) and 30 to 80 wt % (specifically, 30 to 75 wt %, 35 to 75 wt %, 40 to 72 wt %, 45 to 70 wt % or 50 to 70 wt %) of a biodegradable polymer (e.g., polylactic acid (PLA)) may be included.

[0059] When the plant growth promoter according to the present disclosure is applied to plants, the application amount is not particularly limited, but can be 0.001 to 5 wt%, 0.005 to 4 wt%, 0.01 to 3 wt%, 0.05 to 2 wt%, 0.1 to 1 wt%, 0.001 to 0.1 wt%, 0.1 to 0.3 wt%, 0.3 to 0.5 wt%, or 0.5 to 3 wt%, based on the total weight of the soil in which the plant is planted. When the application amount is within the above range, the growth promotion of the plant can be economically enhanced.

[0060] When the plant growth promoter according to the present disclosure is applied to soil sown with plant seeds, the seed germination rate can be 80% or more, 82% or more, 83% or more, 84% or more, 85% or more, 87% or more, 89% or more, 90% or more, 93% or more, 95% or more, 97% or more or 99% or more, indicating that the plant growth promotion effect is excellent. Specifically, the seed germination rate can be 80 to 100%, 82 to 100%, 83 to 99.9%, 83 to 99.8%, 84 to 99.7%, 85 to 99.6%, 88 to 99.5% or 90 to 99.4%.

[0061] According to the plant growth promoter of the present disclosure, various plants can be promoted to grow. Specifically, the plant can be at least one selected from the group consisting of: rice, barley, lettuce, Arabidopsis, cucumber and corn. In particular, according to the plant growth promoter of the present disclosure, the growth of plant roots can be promoted.

[0062] Composition for promoting plant growth

[0063] The composition for promoting plant growth according to the present disclosure comprises the above-mentioned plant growth promoter. Specifically, the composition for promoting plant growth according to the present disclosure may comprise a plant growth promoter, which comprises only the above-mentioned polyhydroxyalkanoate (PHA) or comprises the above-mentioned polyhydroxyalkanoate (PHA) and a biodegradable polymer (e.g., polylactic acid (PLA)). The composition for promoting plant growth according to the present disclosure comprises the above-mentioned plant growth promoter, and when applied to soil for sowing plant seeds, the seed germination rate is 80% or higher (specifically, 80 to 100%, 82 to 99.9%, 83 to 99.8%, 84 to 99.7% or 85 to 99.5%), so its ecotoxicity is extremely low and has an excellent plant growth promoting effect, thereby improving plant productivity.

[0064] The content of the plant growth promoter contained in the composition for promoting plant growth, based on the total weight of the composition for promoting plant growth, can be specifically 0.001 to 10 weight %, 0.005 to 5 weight %, 0.007 to 3 weight %, 0.009 to 2 weight % or 0.01 to 1 weight %.

[0065] Meanwhile, the composition for promoting plant growth according to the present disclosure may further include an additive (active ingredient) that can help plant growth. Specifically, the additive may include at least one selected from the group consisting of: plant growth regulators, fungicides, insecticides, acaricides, nematicides and herbicides.

[0066] The plant growth regulator may specifically be at least one selected from the group consisting of L-glutamic acid, L-proline, aminoethoxyvinylglycine, chlormequat, chlorpropamide, cyclopropane, dikegulac, butyric acid hydrazide, ethephon, fluazifop, flumetrazone, chlorfenapyr, gibberellin, maleic acid hydrazide salt, mepiquat, methylcyclopropene, benzylaminopurine, paclobutrazol, prohexadione, thidiazuron, tributyl trithiophosphate, trifloxylic acid ethyl and uniconazole.

[0067] The fungicide may specifically be at least one selected from the group consisting of benzimidazole compounds, succinate dehydrogenase inhibitor compounds (SDHI compounds), strobilurin-based compounds, phenylamide compounds, dicarboximide compounds, anilinopyrimidine compounds, carbamate compounds, quinoline compounds, organophosphorus compounds and carboxamide compounds.

[0068] The insecticide may specifically be at least one selected from the group consisting of a carbamate compound, a pyrethroid compound, a neurotoxin compound, a neonicotinoid compound, a benzoylurea compound, and an organochlorine compound.

[0069] The acaricide may specifically be at least one selected from the group consisting of acequinoxaline, sulfamethoxam, amitraz, azocyclotin, bifenazate, bromocriptine, chlorphenesone, chlorphenesone, phenisobromate, benzathine, clofentezine, cyanoxam, cyfluthrin, tricyclidine, diplovidazine, chloranil, etoxazole, fenazaquin, fenbutatin, fenpyroximate, fenthiocarb, pyrimidifen, hexythiazox, propargite (BPPS), piflubumide, pyridaben, pyrimidifen, spirocyclofen, spiromesifen, tebufenpyrad, tetradipamide, tetraradiphone, asainonapyr, cyetpyrafen and flupentiophenox.

[0070] The nematicide may specifically be at least one selected from the group consisting of 1,3-dichloropropylene (DD), dichlorodiisopropyl ether (DCIP), methyl isothiocyanate, cadusafos, thiazolyl, imiciafos, nemadectin, cyclobuttripluram, and thioxazaphene.

[0071] The herbicide can specifically be at least one selected from the group consisting of: amino acid compounds, cyclohexanedione compounds, acetamide compounds, bipyridine compounds, aryloxyphenoxypropionic acid compounds, carbamate compounds, pyridine compounds, urea compounds, dinitroaniline compounds, phenoxyacetic acid compounds and triazine compounds.

[0072] In addition, the composition for promoting plant growth according to the present disclosure may further include an aqueous solvent (eg, purified water, etc.) and / or soil to adjust its concentration (or viscosity).

[0073] The composition for promoting plant growth according to the present disclosure can show a growth-promoting effect on all general plants. Specifically, examples of plants include Gramineae, such as rice, wheat, barley, rye, oats, triticale, corn, sorghum, sugarcane, lawn grass, bentgrass, Bermuda grass, fescue and ryegrass; Cruciferae, such as Arabidopsis; Leguminosae, such as soybean, peanut, kidney bean, pea and adzuki bean; Convolvulaceae, such as sweet potato; Solanaceae, such as pepper, green pepper, tomato, eggplant and potato; Polygonaceae, such as buckwheat; Asteraceae, such as lettuce and sunflower; Araliaceae, such as ginseng; Cruciferae, such as rapeseed, Chinese cabbage, turnip, cabbage and radish; Chenopodiaceae, such as beet; Malvaceae, such as cotton; Rubiaceae, such as coffee tree; Sterculiaceae, such as cocoa; Theaceae, such as tea; Cucurbitaceae, such as watermelon, melon, cucumber and pumpkin; Liliaceae, such as onion, leek and garlic; Rosaceae, such as strawberry, apple, almond, apricot, plum, cherry, peach and pear; Umbelliferae, such as carrot; Araceae, such as taro; Anacardiaceae, such as mango; Bromeliaceae, such as pineapple; Caricapae, such as papaya; Diospyros, such as persimmon; Ericaceae, such as blueberry; Juglandaceae, such as pecan; Musaceae, such as banana; Oleaceae, such as olive; Arecaceae, such as coconut palm and date palm; Rutaceae, such as tangerine, orange, grapefruit and lemon; Vitaceae, such as grape; and flowers and ornamental plants, non-fruit trees and other ornamental plants. In particular, the composition for promoting plant growth according to the present disclosure can have an excellent effect of promoting the growth of monocotyledonous plants such as Gramineae (such as barley and corn) and dicotyledonous plants such as Cucurbitaceae (such as cucumber) and Cruciferae (such as Arabidopsis).

[0074] Invention Mode

[0075] Hereinafter, the present disclosure will be described in detail by way of examples, but the scope of the present disclosure is not limited to the examples.

[0076] Example 1

[0077] A plant growth promoter including 100 wt % of a semicrystalline polyhydroxyalkanoate (scPHA, P(3HB-co-4HB) copolymer) having a 4HB repeating unit ratio of 10 mol % and a molecular weight of about 400,000 g / mol was prepared.

[0078] Example 2

[0079] A plant growth promoter including 100 wt % of a semicrystalline polyhydroxyalkanoate (scPHA, P(3HB-co-4HB) copolymer) having a 4HB repeating unit ratio of 10 mol % and a molecular weight of about 800,000 g / mol was prepared.

[0080] Example 3

[0081] A plant growth promoter including 100 wt % of an amorphous polyhydroxyalkanoate (aPHA, P(3HB-co-4HB) copolymer) having a 4HB repeating unit ratio of 33 mol % and a molecular weight of about 600,000 g / mol was prepared.

[0082] Example 4

[0083] A plant growth promoter comprising 70 wt % polylactic acid (Natureworks, M4032) and 30 wt % amorphous polyhydroxyalkanoate (aPHA, P(3HB-co-4HB) copolymer) having a 4HB repeating unit ratio of 33 mol % and a molecular weight of approximately 400,000 g / mol was prepared.

[0084] Example 5

[0085] A plant growth promoter comprising 50 wt % polylactic acid (Natureworks, M4032) and 50 wt % amorphous polyhydroxyalkanoate (aPHA, P(3HB-co-4HB) copolymer) having a 4HB repeating unit ratio of 33 mol % and a molecular weight of approximately 450,000 g / mol was prepared.

[0086] Comparative Example 1

[0087] A plant growth promoter comprising 100 wt % of polylactic acid (PLA) (Nature Works, M4032) was prepared.

[0088] Comparative Example 2

[0089] A plant growth promoter comprising 100 wt % of polyhydroxybutyrate-co-hydroxyvalerate (PHBV, P(3HB-co-3HV) copolymer) (Tian'an, China) was prepared.

[0090] Comparative Example 3

[0091] A plant growth promoter containing 100 wt % of polybutylene adipate-co-terephthalate (PBAT) (ANKOR, Korea) was prepared.

[0092] Comparative Example 1

[0093] Natural soil prepared according to EN17033 standard was used. Specifically, the soil was collected from a rice-growing area located in Cheorwon-gun, Gangwon Province. The physical and chemical properties of the collected soil are shown in Table 1 below.

[0094] [Table 1]

[0095]

[0096] Comparative Example 2

[0097] Standard materials conforming to EN17033 (Sigma-Aldrich, PHB standard materials) were used.

[0098] The Examples, Comparative Examples and Control Examples are summarized in Table 2 below.

[0099] [Table 2]

[0100]

[0101]

[0102] Test Example 1. Germination Rate Evaluation 1

[0103] Monocotyledonous barley and dicotyledonous lettuce were sown in soil and their germination rate was evaluated. Specifically, the treatment group in which 50 barley seeds and 50 lettuce seeds were sown respectively was placed in a growth chamber where temperature, humidity and light conditions were controlled. The germination was observed for about three days. For the treatment group, natural soil was mixed with a plant growth promoter in the form of a powder in an amount of 1.0 weight % relative to the total weight of the soil and stored in a temperature and humidity controlled chamber (23°C and 60% RH). Soil with a biodegradability exceeding 50% (water content of about 10% (w / w)) was used. In addition, the germination conditions of the growth chamber were as follows.

[0104] Germination (growth) temperature of barley seeds and lettuce seeds: 25±2℃

[0105] Humidity: 40 to 60%

[0106] According to the prior art reference, when the germination rate of comparative example 1 exceeds 90%, it can be understood that the ecotoxicity of the substance is low. If it is confirmed that the germination rate of the embodiment is equal to or higher than the germination rate of comparative example 1, it can be understood that the result of promoting germination is achieved.

[0107] After evaluation, the germination rate was converted into a percentage according to the following formula 1. The results are shown in Tables 3 and 4 below.

[0108] [Formula 1]

[0109] Germination rate (%) = S1 / S t ×100

[0110] S t : Number of seeds sown in the treatment group

[0111] S1: The number of germinated seeds among the seeds sown in the treatment group (seeds with young roots (radicles) or young sprouts (embryos) are counted as germinated seeds)

[0112] [Table 3]

[0113]

[0114] [Table 4]

[0115]

[0116] Referring to Table 3 and Table 4 above, it was confirmed that the germination rates of Examples 1 and 2, which respectively used the plant growth promoter of the present disclosure, were equal to or higher than those of Control Examples 1 and 2, indicating that a plant growth promoting effect was achieved.

[0117] Test Example 2. Germination Rate Evaluation 2

[0118] Monocotyledonous plant barley and dicotyledonous plant lettuce were sown in culture dishes, and their germination rates were evaluated. Specifically, the surfaces of barley seeds and lettuce seeds were sterilized with 3% H2O2 and washed three times with distilled water. A sample with a concentration of 1% (a composition in which the plant growth promoter of Example 1 was diluted in pure water) was placed on filter paper in a culture dish, and the sterilized seeds were arranged in each culture dish, which was then sealed with paraffin and cultured in a dark place at 23°C for 3 days. Three days after the start of the culture, roots were observed to have grown from the seeds. The results are as follows: Figure 1 shown.

[0119] Figure 1 (a) shows the germination level of barley seeds, Figure 1 (b) shows the germination level of lettuce seeds. It has been confirmed that roots have grown from the seeds and have germinated well.

[0120] Test Example 3. Evaluation of dry weight yield

[0121] The same treatment group as that used in Test Example 1 was prepared. 50 lettuce seeds and 50 barley seeds were sown, respectively, and grown at room temperature for 14 days. Then, the grown lettuce and barley were harvested and dried at 65°C to remove moisture. The weight of the obtained dry matter was measured. Then, the measurement results are shown in Tables 5 and 6 below.

[0122] [Table 5]

[0123]

[0124] [Table 6]

[0125]

[0126] Referring to Tables 5 and 6 above, it was confirmed that the dry matter weights of Examples 1 and 2, which respectively used the plant growth promoter of the present disclosure, were equal to or higher than the dry matter weights of Control Examples 1 and 2, indicating that a plant growth promoting effect was achieved.

[0127] Test Example 4. Germination Rate Evaluation 3

[0128] Corn and cucumber seeds were sown in soil and their germination rates were evaluated. Specifically, treatments sown with corn and cucumber seeds were placed in a growth chamber with controlled temperature, humidity, and light conditions to observe germination. The results are shown in Figure 2 and Figure 3 For the treatment group, natural soil was mixed with a plant growth promoter in a powder form in an amount of 0.1 wt% relative to the total weight of the soil, and stored in a temperature and humidity controlled room (23°C and 60% RH). Soil with a biodegradability of more than 50% (water content of about 10% (w / w)) was used. In addition, the germination conditions of the growth room were as follows.

[0129] The germination (growth) temperature of corn seeds and cucumber seeds is 25℃

[0130] Humidity: 60%

[0131] Light: 16 hours / Dark: 8 hours

[0132] Figure 2 is the evaluation result of cucumber germination rate, and Figure 3 is the evaluation result of corn germination rate. With reference to these results, it is confirmed that the germination rates of Examples 1, 2, 4 and 5 using the plant growth promoter of the present invention are the same as or higher than those of the control example 1 and the control examples 1 to 3, indicating that the plant growth promotion effect is achieved. In particular, with reference to the results of evaluating the germination rate of cucumber, it is confirmed that when the plant growth promoter of the present invention is used, germination occurs in a relatively short time (within 3 days), and the plant growth promoter of the present invention can improve the germination rate.

[0133] Test Example 5. Evaluation of plant growth promoting effect 1

[0134] The soil fertilizer application method was used to evaluate the growth-promoting effect on corn. Specifically, the treatment group sown with corn seeds was placed in a growth room with controllable temperature, humidity, and light conditions. The growth was observed for about two weeks. For the treatment group, natural soil was mixed with a plant growth promoter in powder form in an amount of 0.1 weight % relative to the total weight of the soil and stored in a temperature and humidity controlled room (23°C and 60% RH). Soil with a biodegradability of more than 50% (water content of approximately 10% (w / w)) was used. In addition, the growth conditions of the growth chamber are as follows. During growth, the fresh weight (live weight) of the corn roots was measured. The results are as follows. Figure 4 shown.

[0135] Corn seed germination (growth) temperature: 25℃

[0136] Humidity: 60%

[0137] Reference Figure 4 It was confirmed that the fresh weight of corn roots of Examples 1, 2, 4, and 5, each of which used the plant growth promoter of the present invention, was 60 to 80% heavier than that of Comparative Examples 1 to 3, indicating that an excellent plant growth promoting effect was achieved.

[0138] Test Example 6. Evaluation of plant growth promoting effect 2

[0139] The soil fertilizer application method was used to evaluate the growth-promoting effect on cucumber. Specifically, the treatment group in which cucumber seeds were sown was placed in a growth room with controllable temperature, humidity, and light conditions. The growth was observed for about 20 days. For the treatment group, natural soil was mixed with a plant growth promoter in powder form in an amount of 0.1 weight % relative to the total weight of the soil and stored in a temperature and humidity controlled room (23°C and 60% RH). Soil with a biodegradability of more than 50% (water content of approximately 10% (w / w)) was used. In addition, the growth conditions of the growth room were as follows. During growth, the fresh weight (live weight) of the cucumber roots was measured. The results are as follows. Figure 5 shown.

[0140] Cucumber seed germination (growth) temperature: 25℃

[0141] Humidity: 60%

[0142] Reference Figure 5 It was confirmed that the fresh weight of cucumber roots of Examples 1, 2, 4, and 5, each of which used the plant growth promoter of the present invention, was 40 to 160% heavier than that of Comparative Examples 1 to 3, indicating that an excellent plant growth promoting effect was achieved.

Claims

A plant growth promoter comprising polyhydroxyalkanoate (PHA). 2 . The plant growth promoter according to claim 1 , wherein the content of the polyhydroxyalkanoate (PHA) is 1 to 100 wt % based on the total weight of the plant growth promoter.

3. The plant growth promoter according to claim 1, wherein the polyhydroxyalkanoate (PHA) comprises a repeating unit derived from at least one selected from the group consisting of 3-hydroxybutyrate (3HB), 4-hydroxybutyrate (4HB), 3-hydroxypropionate (3HP), 3-hydroxyhexanoate (3HH), 3-hydroxyvalerate (3HV), 4-hydroxyvalerate (4HV), 5-hydroxyvalerate (5HV) and 6-hydroxyhexanoate (6HH). The plant growth promoter according to claim 1 , wherein the polyhydroxyalkanoate (PHA) comprises a repeating unit derived from 4-hydroxybutyrate (4HB).

5. The plant growth promoter according to claim 4, wherein the content of the repeating unit derived from 4-hydroxybutyrate (4HB) is 1 to 80 mol% based on the total moles of polyhydroxyalkanoate (PHA).

6. The plant growth promoter according to claim 1, wherein the polyhydroxyalkanoate (PHA) is a poly(3-hydroxybutyrate-co-4-hydroxybutyrate) copolymer comprising a repeating unit derived from 3-hydroxybutyrate (3HB) and a repeating unit derived from 4-hydroxybutyrate (4HB). 7 . The plant growth promoter according to claim 6 , wherein the molar ratio of the repeating unit derived from 3-hydroxybutyrate (3HB) to the repeating unit derived from 4-hydroxybutyrate (4HB) is 20:80 to 99:

1. 8 . The plant growth promoter according to claim 1 , wherein the molecular weight of the polyhydroxyalkanoate (PHA) is 200,000 to 1,000,000 g / mole.

9. The plant growth promoter according to claim 1, further comprising a biodegradable polymer.

10. The plant growth promoter according to claim 9, wherein the biodegradable polymer comprises at least one selected from the group consisting of polylactic acid (PLA), polyvinyl alcohol (PVOH), ethylene-vinyl alcohol copolymer (EVOH), polybutylene adipate-terephthalate copolymer (PBAT), polybutylene succinate (PBS), polycaprolactone (PCL) and thermoplastic starch (TPS).

11. The plant growth promoter according to claim 9, wherein the biodegradable polymer is polylactic acid (PLA).

12. The plant growth promoter according to claim 9, wherein the content of the polyhydroxyalkanoate (PHA) is 20 to 70 wt%, and the content of the biodegradable polymer is 30 to 80 wt%, based on the total weight of the plant growth promoter.

13. A composition for promoting plant growth, comprising the plant growth promoter according to any one of claims 1 to 12. 14 . The composition for promoting plant growth according to claim 13 , wherein the content of the plant growth promoter is 0.001 to 10 wt % based on the total weight of the composition for promoting plant growth.

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