JP2008162912A - Method for increasing root tubercle - Google Patents

Abstract

<P>PROBLEM TO BE SOLVED: To provide a simple and effective method for increasing root tubercles formed by a leguminous plant or the like. <P>SOLUTION: The method for increasing the root tubercles includes applying a composition which contains 1-10,000 ppm of a compound (A) having a specific structure having a hydrocarbon group with a specified number of carbons [and which may further contain at least one selected from a surfactant (B) and a chelating agent (C)] to a plant forming the root tubercles. <P>COPYRIGHT: (C)2008,JPO&INPIT

Description

  The present invention relates to a method for increasing the amount of nodules formed by a plant.

  The administration of a large amount of nitrogen and phosphorus causes deterioration of the soil and water environment, which has become a problem for modern society. For example, nitrate fertilizers such as nitrates are known to run away from the soil, leading to groundwater contamination and eutrophication of rivers, lakes, and the ocean. Nitrogen by biological nitrogen fixation does not run out to the environment as much as chemical fertilizers, so it is expected to lead to reduction of environmental pollution, and there is no method of utilizing legumes such as legumes that fix nitrogen and symbiotic nitrogen fixation Non-Patent Documents 1 and 2 point out the importance of techniques related to biological nitrogen fixation, such as methods for improving plants to nitrogen-fixed plants. As shown in Non-Patent Document 3, the symbiotic relationship between the nitrogen-fixing fungus and the host plant is the “symbiotic nitrogen-fixing system” that creates a knot-like tissue (nodule) inside the plant body and the root of the plant. There is a "rhizosphere cooperative nitrogen fixation system" in which nitrogen-fixing bacteria inhabit the rhizosphere around the. In the former “symbiotic nitrogen fixation”, the nodules are present inside the plant body, and all of the nitrogen molecules are taken up and converted to amino acids via ammonia, and they are washed away into the environment. Not used by plants. From this point of view, a technique for enhancing biological nitrogen fixation, particularly nitrogen fixation by nodules, is an important technique in the environmental problem of normalizing material circulation.

  In the 21st century society, environmental conservation type agricultural technology development including improvement of geopower in the long term is indispensable, but technology development related to biological nitrogen fixation represented by legumes is an important technology One of them.

  It is known that the amount of nitrogen accumulation in plants affects the yield of legumes. Similar to fertilization, nitrogen fixation may be considered to be linked to increased bean yield. However, as described in Non-Patent Document 4, it is difficult to obtain a high yield with only fixed nitrogen (2nd page, 10th line), and even if the root nodules are increased, the growth yield may be inferior due to excessive root nodules. I know that there is something (12th line, page 2). That is, there is no positive correlation between a large amount of nodule and an increase in legume yield, and it can be said that “a technique for increasing the amount of nodule” is not necessarily a technique for increasing the yield.

  Patent Document 1 discloses a method of growing a plant that forms nodules and a method of growing mycorrhiza by incorporating charcoal and a small amount of chemical fertilizer or organic fertilizer into field soil. Patent Documents 2 to 4 also proliferate and activate rhizobia (rhizobial bacteria) using methods such as mixing specific compounds in field soils or adding specific compounds to culture rhizobia. Techniques to do this are disclosed.

Furthermore, Patent Document 5 discloses that an acetic acid bacterium component is used by being applied to soil as a growth promoter for leguminous crops. Patent Document 6 discloses a plant vitality agent composed of a monohydric alcohol having 12 to 24 carbon atoms. Patent Document 7 discloses a crop yield-increasing agent comprising a specific compound such as a monohydric alcohol having 12 to 24 carbon atoms.
"Science of the soil sphere" (Asakura Shoten, 71-75p) “I understand agriculture” (Asahi Shimbun, 69p, 70p, 140p) Chemistry and Biology Vol.43, No.12, 2005 Agriculture, Forestry and Fisheries Research Results Library [online], Agriculture, Forestry and Fisheries Research Literature Solution, No. 27 “Technology Development for Improvement of Soybean Self-Sufficiency”, Chapter 2 Physiological Ecology High yield (4) Nitrogen metabolism, Internet <URL: http://rms1.agsearch.agropedia.affrc.go.jp/contents/kaidai/daizuNo27/27-2-2-4_h.html> JP 60-49717 A JP 49-30151 JP 51-63254 A JP-A-63-304977 JP 2006-248898 A JP 2000-198703 A JP 2002-265305 A

However, for plants that form nodules such as legumes, as a way of increasing the nodules, Patent Documents 1 to 5 are hardly to say that sufficient effect with a simple process is obtained, also, Patent Document 6 In No. 7, no mention is made of increasing the root nodules for the plants forming the root nodules, and no mention is made of the optimum processing time or concentration for increasing the root nodules. In legumes, there is no simple positive correlation between bean yield and nodule mass. For example, Table 5 of Patent Document 1 discloses a method for increasing the pod pod number and pod weight, but among the treatment methods for increasing the pod pod number and pod weight, the number and weight of root nodules are also shown. Is increasing [Patent Document 1, Invention (A) in Table 5], and is decreasing [Invention (B)]. In other words, it is not possible to make an analogy regarding the amount of nodules by merely describing the increase in sales.

  The subject of this invention is providing the simple and effective method which can increase the nodule amount which a plant forms.

  The present invention relates to a method for increasing nodules, in which a composition containing a compound (A) represented by the following general formula (1) [hereinafter referred to as component (A)] is applied to a plant that forms nodules.

[Wherein R ¹ is a hydrocarbon group having 10 to 22 carbon atoms, R ² is a hydrogen atom, a hydroxyl group or a hydrocarbon group having 1 to 24 carbon atoms, and R ³ is a hydrogen atom or a hydrocarbon group having 1 to 24 carbon atoms. Represents. ]

  Moreover, this application is related with the nodule increasing agent composition containing the compound (A) represented by the said General formula (1).

  According to the present invention, a plant is formed that leads to solving environmental conservation problems such as normalizing the balance of material balance such as nitrogen on a global scale represented by groundwater contamination and ocean eutrophication. There is provided a method of increasing nodules that can easily and effectively increase the nodules.

<(A) component>
In the general formula (1) of the compound (A) represented by the following general formula (1) (hereinafter referred to as the compound (A)), the hydrocarbon groups of R ¹ , R ² and R ³ are saturated and unsaturated, respectively. Any of the above, preferably saturated, and may be any of linear, branched and cyclic, preferably linear or branched, particularly preferably linear. The total carbon number of the hydrocarbon group may be an odd number or an even number, but an even number is preferable.

Also, the total number of carbon atoms of R ^1, R ^2, R ³ are all preferably 50 or less, more preferably 12 to 48, more preferably from 16 to 44.

In the general formula (1), the carbon number of R ¹ is preferably 10 to 22, more preferably 12 to 20, more preferably from 14 to 18. The compound represented by the general formula (1) preferably has a total carbon number of 12 to 48, more preferably 16 to 28, and particularly preferably 16 to 24. Further, those having a total carbon number of 12 to 24 and one hydroxyl group are preferred, and those having a total carbon number of 16 to 22 and one hydroxyl group are particularly preferred. Specific examples of the compound represented by the general formula (1) include the following.

(A1)
1-alkanol represented by CH ₃ (CH ₂ ) _o-1 OH (o is an integer of 12 to 24, preferably 14 to 22, more preferably 16 to 20). That is, as the compound represented by the general formula (1), a monohydric alcohol having 12 to 24 carbon atoms can be given. Specifically, 1-dodecanol, 1-tridecanol, 1-tetradecanol, 1-pentadecanol, 1-hexadecanol, 1-heptadecanol, 1-octadecanol, 1-nonadecanol, 1-icosanol 1-henicosanol, 1-docosanol, 1-tricosanol, 1-tetracosanol.

(A2)
2-alkanol represented by CH ₃ CH (OH) (CH ₂ ) _p-3 CH ₃ (p is an integer of 12 to 24, preferably 16 to 24, more preferably 16 to 20). Specifically, 2-dodecanol, 2-tridecanol, 2-tetradecanol, 2-pentadecanol, 2-hexadecanol, 2-heptadecanol, 2-octadecanol, 2-nonadecanol, 2-icosanol Etc.

(A3)
_{CH 2 = CH (CH 2)} q-2 OH (q is 12 to 24, preferably 16 to 24, more preferably an integer of 16 to 20) include terminally unsaturated alcohol represented by. Specific examples include 11-dodecene-1-ol, 12-tridecene-1-ol, 15-hexadecene-1-ol, and the like.

(A4)
Examples of other unsaturated long chain alcohols include oleyl alcohol, elaidyl alcohol, linoleyl alcohol, linoleyl alcohol, eleostearyl alcohol (α or β), ricinoyl alcohol, and the like.

(A5)
_{HOCH 2 CH (OH) (CH} 2) r-2 H (r is 12 to 24, preferably 16 to 24, more preferably an integer of 16 to 20) include 1,2-diol represented by. Specific examples include 1,2-dodecanediol, 1,2-tetradecanediol, 1,2-hexadecanediol, 1,2-octadecanediol, and the like.

  Of the above (A1) to (A5), (A1), (A2), (A4), (A5) are preferable, (A1), (A2), (A4) are more preferable, and (A1), (A4) ) Is more preferable, and (A1) is particularly preferable.

<Composition>
The composition used in the present invention preferably contains 1 to 10,000 ppm (weight ratio, hereinafter the same) of the component (A). It is preferably contained at a concentration of 10 to 3,000 ppm, more preferably 10 to 1,000 ppm, still more preferably 50 to 600 ppm, and particularly preferably 60 to 400 ppm.

  In addition to the component (A), the composition used in the present invention further includes a surfactant (B) of the component (A) [hereinafter referred to as component (B)] and a chelating agent (C) [hereinafter, (Referred to as component (C)). In particular, it is preferable to use both the component (B) and the component (C).

<(B) component>
As the component (B), the following surfactants are preferably used for the purpose of emulsifying, dispersing, solubilizing or promoting penetration of the compound (A).

  Nonionic surfactants include sorbitan fatty acid ester, polyoxyalkylene sorbitan fatty acid ester, polyoxyalkylene fatty acid ester, glycerin fatty acid ester, polyoxyalkylene glycerin fatty acid ester, polyglycerin fatty acid ester, polyoxyalkylene polyglycerin fatty acid ester, sorbitol Fatty acid ester, polyoxyalkylene sorbitol fatty acid ester, sucrose fatty acid ester, resin acid ester, polyoxyalkylene resin acid ester, polyoxyalkylene alkyl ether, polyoxyalkylene alkyl phenyl ether, alkyl (poly) glycoside, polyoxyalkylene alkyl ( Poly) glycoside, alkyl alkanolamide, sugar fatty acid amide and the like. Here, examples of the sugar fatty acid amide include those having a structure in which a hydrophobic group is bonded to an saccharide or sugar alcohol, for example, a sugar fatty acid amide such as a fatty acid amide of glucose or fructose. Further, those having a structure in which a hydrophobic group is amide-bonded to a sugar or sugar alcohol having an amino group, for example, a sugar fatty acid amide such as a fatty acid amide of N-methylglucamine can be used. Among the nonionic surfactants as described above, at least one selected from ether group-containing nonionic surfactants and ester group-containing nonionic surfactants not containing nitrogen atoms is preferable. Specifically, polyoxyalkylene (particularly ethylene) sorbitan fatty acid ester, polyoxyalkylene (particularly ethylene) glycerin fatty acid ester, and sucrose fatty acid ester are preferred.

  Further, when the component (B) is a nonionic surfactant, the above-mentioned Griffin has an HLB of preferably 10 or more, more preferably 12 or more.

  Examples of the anionic surfactant include carboxylic acid-based surfactants, sulfonic acid-based surfactants, sulfate ester-based surfactants, and preferably one or more selected from carboxylic acid-based surfactants and phosphate ester-based surfactants. .

  Examples of the carboxylic acid-based surfactant include fatty acids having 6 to 30 carbon atoms or salts thereof, polyvalent carboxylates, polyoxyalkylene alkyl ether carboxylates, polyoxyalkylene alkylamide ether carboxylates, rosinates, Examples include dimer acid salts, polymer acid salts, tall oil fatty acid salts, and esterified starches. Of these, esterified starch is preferred. Among the esterified starches, alkenyl succinylated starch (also referred to as alkenyl succinate esterified starch or alkenyl succinate starch) is preferable, and octenyl succinylated starch is particularly preferable. Etc.].

  Examples of sulfonic acid surfactants include alkylbenzene sulfonates, alkyl sulfonates, alkyl naphthalene sulfonates, naphthalene sulfonates, diphenyl ether sulfonates, alkyl naphthalene sulfonic acid condensates, and naphthalene sulfonic acid condensations. Examples include physical salts.

  Examples of sulfate surfactants include alkyl sulfates, polyoxyalkylene alkyl sulfates, polyoxyalkylene alkyl phenyl ether sulfates, tristyrenated phenol sulfates, polyoxyalkylene distyrenated phenol sulfates. And alkyl polyglycoside sulfate.

Examples of the phosphate ester surfactant include alkyl phosphate ester salts, alkylphenyl phosphate ester salts, polyoxyalkylene alkyl phosphate ester salts, and polyoxyalkylene alkylphenyl phosphate ester salts.
Examples of the salt include metal salts (Na, K, Ca, Mg, Zn, etc.), ammonium salts, alkanolamine salts, aliphatic amine salts, and the like.

  Examples of amphoteric surfactants include amino acids, betaines, imidazolines, and amine oxides.

  Examples of the amino acid system include acyl amino acid salts, acyl sarcosine salts, acyloylmethylaminopropionates, alkylaminopropionates, acylamidoethylhydroxyethylmethylcarboxylates, and the like.

  Examples of the betaine series include alkyl dimethyl betaine, alkyl hydroxyethyl betaine, acylamidopropyl hydroxypropyl ammonia sulfobetaine, ricinoleic acid amidopropyl dimethyl carboxymethyl ammonia betaine, and the like.

  Examples of the imidazoline series include alkyl carboxymethyl hydroxyethyl imidazolinium betaine, alkyl ethoxy carboxymethyl imidazolium betaine, and the like.

  Examples of amine oxides include alkyldimethylamine oxide, alkyldiethanolamine oxide, alkylamidopropylamine oxide, and the like.

  The component (B) may be used alone or in combination of two or more. Moreover, when these (B) components contain a polyoxyalkylene group, Preferably it has a polyoxyethylene group, The average added mole number is 1-300, Preferably it is more than 5 and 100 or less. .

  When a monohydric alcohol having 12 to 24 carbon atoms is used as the compound (A), the component (B) includes an ester group-containing nonionic surfactant and an ether group-containing nonionic surfactant that does not contain a nitrogen atom. One or more selected from agents, amphoteric surfactants, carboxylic acid anionic surfactants and phosphoric acid anionic surfactants are preferred. In particular, one or more selected from an ester group-containing nonionic surfactant, an ether group-containing nonionic surfactant not containing a nitrogen atom, and a carboxylic acid anionic surfactant are preferred. That is, as a composition used in the present invention, particularly a treatment liquid, a monohydric alcohol having 12 to 24 carbon atoms, an ester group-containing nonionic surfactant, an ether group-containing nonionic surfactant not containing a nitrogen atom, Examples thereof include those containing one or more surfactants selected from amphoteric surfactants, carboxylic acid anionic surfactants, and phosphoric acid anionic surfactants.

<(C) component>
As the component (C), when an organic acid having a chelating ability as described below or a salt thereof is used in combination, the effect of increasing the amount of nodules is further improved. Specifically, citric acid, gluconic acid, malic acid, heptonic acid, oxalic acid, malonic acid, lactic acid, tartaric acid, succinic acid, fumaric acid, maleic acid, adipic acid, glutaric acid and other oxycarboxylic acids, polyvalent carboxylic acids And potassium salts, sodium salts, alkanolamine salts, aliphatic amine salts and the like thereof. In addition, the effect of increasing the amount of nodules is also improved by mixing chelating agents other than organic acids. Examples of the chelating agent to be mixed include aminocarboxylic acid chelating agents such as EDTA, NTA, and CDTA.

  In the composition used in the present invention, when the components (B) to (C) are used in combination, the ratio of each component is 10 to 20,000 parts by weight of the component (B) with respect to 100 parts by weight of the compound (A). In particular, 100 to 2,000 parts by weight, (C) component 0 to 50,000 parts by weight, particularly 10 to 5,000 parts by weight are preferred.

  In addition, the composition used in the present invention contains 0 to 5000 parts by weight, particularly 10 to 500 parts by weight, of other nutrient sources (saccharides, amino acids, vitamins, etc.) with respect to 100 parts by weight of the compound (A). You can also

  The form of the nodule increasing agent composition containing the component (A) may be any of liquid, flowable, paste, wettable powder, granule, powder, tablet and the like. In use, the composition base or a dilution thereof is usually used as an aqueous solution, aqueous dispersion or emulsion of the component (A). Moreover, it may be used in a solid state such as a powder or a granule, and the granule or the powder may contain an excipient for preventing caking.

  Various means can be used as a method of supplying the composition according to the present invention to the plant forming the nodules. For example, the treatment liquid (liquid composition) is applied directly to the foliage, stems, etc. (stem and foliage spraying), injected into the soil (soil irrigation, soil irrigation, etc.), roots such as hydroponics and rock wool. A method of diluting and supplying to the hydroponic liquid or feed water that is in contact with the water (nutritional culture), or a method of directly spraying the powder to the strainer. As a method for supplying the composition according to the present invention, an appropriate method may be selected depending on the kind of plant forming the nodule and the application time.

  The application amount of the compound (A) in foliar application is preferably 0.02 g / 10a to 10 kg / 10a, more preferably 0.2 g / 10a to 1000 g / 10a. It is preferable to adjust the concentration and the number of application of the component (A) in the composition, particularly the treatment liquid, so that the application amount falls within this category.

  The appropriate amount for one plant body is, for example, when the liquid composition is spread on the surface with beans such as soybeans, preferably from 1 to 100 mL, from the time when the third leaf begins to appear until before the flowering period, More preferably, it is 3-30 mL. The amount of water to be sprayed per unit area varies depending on the planting density, but is preferably 20L to 1000L per 10a.

  The application amount of the compound (A) in soil application is preferably 0.2 g / 10a to 100 kg / 10a, more preferably 2 g / 10a to 10 kg / 10a. It is preferable to adjust the concentration and the number of application of the component (A) in the composition, particularly the treatment liquid, so that the application amount falls within this category.

  (A) As a time which applies a component, the time before a flowering period is preferable, and the time from the time when a 3rd leaf begins to appear to the time before a flowering period is especially preferable. In the case of leguminous plants, it is preferable to apply two or more times between the time when the third leaf begins to appear and before the time of flowering. Here, “the time when the third leaf begins to appear” refers to the time when the bud that becomes the third leaf starts to appear and the tip can be visually confirmed.

  Although the effect which increases a nodule is seen by one process, it is more preferable to apply twice or more. For example, by using it twice or more at intervals of about 5 to 30 days in accordance with the time of soil cultivation treatment and culturing treatment, a higher nodule increasing effect can be obtained compared to the use of only one time.

  The nodule increasing agent composition of this invention contains the said (A) component, and can further contain (B)-(C) component. In the total of the components (A) to (C), the ratio of the component (A) is preferably 0.1 to 90% by weight, and more preferably 1 to 50% by weight. In the case of a liquid composition containing water, it can be a concentrated type used as it is or after being diluted. Moreover, in the case of a composition in a solid state, it may be given to the stock company as it is, or it can be diluted with water and used.

  Plants targeted by the present invention are plants that coexist with the nodules, and specific examples include plants of the legume family, the grass family, the birch family, the asteraceae family, the gummy family, and the bay family. Examples of legumes include soybeans (including green soybeans), azuki bean, kidney beans, peanuts, broad beans, peas, safflower beans, ima bean, mung bean, cowpeas, wisteria, and beans. Among them, the present invention is preferable for soybean, azuki bean, kidney bean, pea, and broad bean, and is particularly preferable for soybean.

Example 1
Table 1 shows the compositions used in the following evaluations. In Table 1, compositions 1, 3, 4, 5 and 10 were prepared by adding component (C) to a liquid obtained by emulsifying compound (A) in water with component (B). Compositions 2 and 7 were prepared by emulsifying compound (A) in water with component (B). Composition 8 was prepared by pulverizing compound (A) with a mixer and dispersing it in water. Composition 6 was prepared by adding component (C) to composition 8. Composition 9 was prepared by mixing component (B) with water. In addition, POE of (B) component shows a polyoxyethylene group, and the number in () shows the average addition mole number of ethylene oxide (the same applies hereafter).

  100 seeds of soybean (variety: Enrei) and rhizobia (trade name: “Rhizobium Mamezo”, Tokachi Agricultural Cooperative Association, Agricultural Chemical Research Laboratories) 0.5 g were mixed to attach the rhizobia to the soybean seed surface. . A commercially available soil (Kureha soil) was put in a pot having a diameter of 12 cm and a depth of 9 cm, and seeds to which the above-mentioned rhizobia were attached were sown in each pot. When the third leaf was developing, each composition shown in Table 1 was sprayed on the stem and leaf surface. Hereinafter, such a time when the nth leaf is developing is referred to as “n leaf stage” (n is an integer). For example, the time when the third leaf is developing is the “three-leaf stage”.

  The amount of sprayed water was 10 mL per soybean seedling in each pot (nothing was sprayed in the untreated area and cultivation was carried out in the same greenhouse). The test area was repeated 10 strains in each test area. 34 days after application (8-leaf stage), the roots of each soybean seedling were washed with water to remove the soil, and nodules formed on the roots were collected. The root nodules formed in each soybean seedling were combined and dried at 70 ° C. until the weight reached equilibrium, and then the weight was measured to obtain the “root nodule dry matter weight (g / strain)”. The nodule dry matter weight of each treatment group is shown in Table 1 as a relative value when the untreated group is 100.

Example 2
In the same manner as in Example 1, soybean seeds with attached rhizobia were sown in pots containing commercial soil (vermiculite). At the time of the third leaf stage, 200 mL of the composition having the composition shown in Table 2 was slowly soil irrigated per pot (the untreated area was cultivated in the same greenhouse without any soil irrigation). The test area was repeated 10 strains in each test area. 34 days after application (8-leaf stage), the roots of each soybean seedling were washed with water to remove the soil, and nodules formed on the roots were collected. Thereafter, “nodule dry matter weight (g / stock)” (relative value) was determined in the same manner as in Example 1. The results are shown in Table 2.

Example 3
By the same method as in Example 1, soybean seeds with attached rhizobia were sown in pots containing commercial soil (Kureha soil). In the third leaf stage, the composition adjusted to the concentration shown in Table 3 of the component (A) with the composition of Table 3 was sprayed on the stem and leaf surface. The amount of sprayed water was 10 mL per soybean seedling in each pot (nothing was sprayed in the untreated area and cultivation was carried out in the same greenhouse). The test area was repeated 10 strains in each test area. 34 days after application (8-leaf stage), the roots of each soybean seedling were washed with water to remove the soil, and nodules formed on the roots were collected. Thereafter, “nodule dry matter weight (g / stock)” (relative value) was determined in the same manner as in Example 1. The results are shown in Table 3.

Example 4
Soybean seeds (enrei) to which rhizobia were attached in the same manner as in Example 1 were sown at a distance of 20 cm between strains at a distance of 60 cm. At each applicable time in Table 4, a composition having the composition shown in Table 4 was sprayed on the stem and leaves. The amount of sprayed water was 100 L / 10a (the untreated area was not sprayed anything and was cultivated in the same field). At the time of arrival, the roots of each soybean seedling were washed with water to remove the cultivation soil, and the nodules formed on the roots were collected. Thereafter, “nodule dry matter weight (g / stock)” (relative value) was determined in the same manner as in Example 1. The results are shown in Table 4.

Example 5
Soybean (Toyohomare) was sown at 9 cm between strains in 45 cm between the ridges. A composition having the composition shown in Table 5 was sprayed on the stems and leaves at each applicable time in Table 5. The amount of sprayed water was 150 L / 10a. (Non-treated areas were not sprayed and were cultivated in the same field.) During the 7-leaf development period, the roots of each soybean seedling were washed with water to remove the cultivated soil, and the nodules formed in the roots were collected. did. Thereafter, “nodule dry matter weight (g / stock)” (relative value) was determined in the same manner as in Example 1. The results are shown in Table 5.

Example 6
By the same method as in Example 1, soybean seeds with attached rhizobia were sown in pots containing commercial soil (Kureha soil). In the 3rd and 7th leaf stages, the composition having the composition shown in Table 6 was sprayed on the stems and leaves. The amount of sprayed water was 10 mL each for soybean seedlings in each pot at the third leaf stage, and 20 mL each at the seventh leaf stage (no treatment was applied to the untreated area, and cultivation was performed in the same greenhouse). The test area was repeated 10 strains in each test area. 14 days after the 7th leaf spraying (flowering period), the roots of each soybean seedling were washed with water to remove the soil, and the nodules formed on the roots were collected. Thereafter, “nodule dry matter weight (g / stock)” (relative value) was determined in the same manner as in Example 1. The results are shown in Table 6.

Claims (8)

A method for increasing nodules, wherein a composition containing a compound (A) represented by the following general formula (1) is applied to a plant forming nodules.

[Wherein R ¹ is a hydrocarbon group having 10 to 22 carbon atoms, R ² is a hydrogen atom, a hydroxyl group or a hydrocarbon group having 1 to 24 carbon atoms, and R ³ is a hydrogen atom or a hydrocarbon group having 1 to 24 carbon atoms. Represents. ] The method for increasing nodules according to claim 1, wherein the compound (A) is a compound in which R ² and R ³ in the general formula (1) are both hydrogen atoms.   The method of increasing nodules according to claim 1 or 2, wherein the composition further comprises at least one selected from (B) a surfactant and (C) a chelating agent.   The method for increasing the nodule according to any one of claims 1 to 3, wherein the plant forming the nodule is a leguminous plant.   The method for increasing nodules according to claim 4, wherein the compound (A) is applied at least once before the flowering period.   The method for increasing nodules according to any one of claims 1 to 5, wherein the composition contains the compound (A) at a concentration of 1 to 10,000 ppm.   The method for increasing nodules according to any one of claims 4 to 6, wherein the compound (A) is applied twice or more from the time when the third leaf begins to appear until before the flowering period. The nodule increasing agent composition containing the compound (A) represented by following General formula (1).

[Wherein R ¹ is a hydrocarbon group having 10 to 22 carbon atoms, R ² is a hydrogen atom, a hydroxyl group or a hydrocarbon group having 1 to 24 carbon atoms, and R ³ is a hydrogen atom or a hydrocarbon group having 1 to 24 carbon atoms. Represents. ]