L-methionine-containing composition for controlling nematodes and method for controlling nematodes

Abstract

The present disclosure addresses the problem of providing: a nematode control composition that exhibits high control activity even when the amount of methionine applied is small; and a control method. The present disclosure pertains to a nematode control composition containing methionine, wherein the methionine includes more than 50 wt% of L-methionine with respect to the total weight of the methionine. Moreover, the present disclosure also provides a nematode control method comprising applying 5-80 kg of methionine per 1,000 m2 of a field.

Description

[Technical Field]

[0001] The present disclosure relates to a composition for controlling nematodes that parasitize plants and hinder their growth, more specifically to a composition for controlling nematodes containing L-methionine. Furthermore, the present disclosure relates to a method for controlling nematodes using L-methionine. [Background technology]

[0002] Plant-parasitic nematodes are nematodes that parasitize plants and are known to cause damage such as stunted growth and plant death. For example, plant-parasitic soil nematodes such as root-knot nematodes, root-lesion nematodes, and cyst nematodes are one of the factors that inhibit crop production, and nematode damage accounts for 16% of the causes of continuous crop damage in Japan. Furthermore, the average yield loss due to nematodes across the world is 12%. Meanwhile, damage caused by plant-parasitic nematodes is also known to occur in the production and utilization of useful plants such as lawns and shrubs. Therefore, it is an urgent task to provide an effective method for controlling nematodes in order to reduce plant damage caused by nematodes and increase crop productivity.

[0003] Nematode control or nematode damage suppression techniques in the agricultural sector can be divided into chemical, physical, biological, and cultural methods. Chemical methods include the use of a range of pesticides supplied in the form of fumigants and granules. Physical methods include those that use heat (solar soil disinfection, hot water soil disinfection, steam disinfection) and flooding treatments that use water (run-off soil, field-field rotation). Biological methods include the use of microbial materials that parasitize or prey on nematodes. Cultural methods include crop rotation, the development and use of nematode-resistant varieties, the development and use of nematode-suppressing green manure, and the use of soil reduction disinfection methods.

[0004] Among these nematode control and suppression techniques, for example, control measures against root-knot nematodes that infest sweet potatoes rely heavily on synthetic pesticides, such as fumigants (e.g., DD agents and chloropicrin fumigants) and granules (e.g., fosthiazate). In contrast, the adoption rate of agricultural methods is extremely low, and physical and biological methods are rarely used (Non-Patent Document 1). However, DD agents are restricted by the US EPA due to their carcinogenicity and other issues, and their pesticide registration in the EU has already expired. Furthermore, chloropicrin is highly irritating to the human body, so its use in crowded environments tends to be avoided. Meanwhile, soil reduction disinfection, one of the agricultural methods, is expected to contribute to the promotion of sustainable agriculture due to its low environmental impact, but its implementation is constrained and its adoption has not progressed.

[0005] Attempts have been made to develop techniques for controlling harmful soil nematodes using amino acids as a control method with minimal environmental impact. Non-Patent Documents 2 and 3 report that DL-amino acids, including D-amino acids, are applied to plants as metabolic inhibitors of L-amino acids, and that among various amino acids, DL-methionine exhibits the highest toxicity to the sweet potato root-knot nematode. The toxicity of DL-methionine to the sweet potato root-knot nematode has also been reported in Non-Patent Documents 4, 3, and 5, and a technique for controlling root-knot nematodes using DL-methionine has also been developed (Patent Document 1). Other nematode species in which DL-methionine toxicity has been demonstrated include the nematode Echinochloa nigricans (Non-Patent Document 2), the wheat cyst nematode (Non-Patent Document 6), the peel nematode (Non-Patent Document 6), the potato cyst nematode (Non-Patent Document 7, Patent Documents 2, and 3), a species of the genus Veronoraimus (Non-Patent Document 8), and a species of the genus Mesoclyconema (Non-Patent Document 8).

[0006] However, there have also been reported cases where the toxicity of DL-methionine did not affect all nematodes. Examples of such nematodes include a type of spiral nematode (Non-Patent Document 2), a false root-knot nematode (Non-Patent Document 6), a root-lesion nematode (Non-Patent Document 6), and a type of long-horn nematode (Non-Patent Document 9). As such, it has become clear that the toxicity of DL-methionine does not affect all nematodes.

[0007] The mechanisms by which methionine exhibits toxicity to nematodes are thought to be oral toxicity and contact toxicity. For example, Non-Patent Document 7 reports that the D- and L-methionine are equally toxic to potato cyst nematodes, and the mechanism of action is said to be oral toxicity. Furthermore, Patent Document 2 reports that the oral toxicity of D-methionine to potato cyst nematodes is lower than that of L-methionine. Meanwhile, with regard to contact toxicity, Non-Patent Document 3 cites Non-Patent Document 4, which states that the DL-methionine exhibited contact toxicity to sweet potato root-knot nematodes, but the L-methionine did not.

[0008] A major problem with using methionine to control nematodes is its plant toxicity. Non-Patent Documents 6, 7, 3, 1, and 10 report that DL-methionine inhibits the growth of tomatoes or potatoes. However, Patent Documents 1 and 2 also reveal that DL-methionine does not provide reliable control effects against potato cyst nematodes and sweet potato root-knot nematodes at doses that do not inhibit plant growth. [Prior art documents] [Patent documents]

[0009] [Patent Document 1] Japanese Patent Application Laid-Open No. 2000-007506 [Patent Document 2] International Publication No. 2019 / 004252 [Patent Document 3] Japanese Patent Publication No. 2022-118806 [Non-patent literature]

[0010] [Non-Patent Document 1] Mizukubo, T. (2015) Trends in nematode control research and technology in Japan - Commemorative project for the 20th anniversary of the Japanese Society of Nematology: Compilation of questionnaires on nematode control (1999-2011) - Journal of the Japanese Society of Nematology 45: 63-76 [Non-patent document 2] Overman, AJ and Woltz, SS 1962. Effects of Amino acid antimetabolites upon nematodes and tomatoes. Florida Agricultural Experiment Stations Journal Series No. 1524: 166-170. [Non-patent document 3] Reddy, PP, Govindu, HC and Setty, KGH 1975. Studies on the effect of amino acids on the root-knot nematode Meloidogyne incognita infecting tomato. Indian Journal of Nematology 5: 36-41. [Non-patent document 4] Setty, KGH 1968 Studies on the biology and host-parasite relationships of root-knot nematode (Meloidogyne spp.) on tomatoes. Ph. D Thesis, univ. Lond. 293pp. [Non-Patent Document 5] Reddy, PP, Govindu, HC and Setty, KGH 1975. Studies on the action of DL-methionine on Meloidogyne incognita infecting tomato. Indian Journal of Nematology 5: 42-48. [Non-patent document 6] Prasad, SK, and Webster, JM 1967. The effect of amino acid antimetabolites on four nematode species and their host plants. Nematologica 13: 318-323. [Non-Patent Document 7] Evans, K. and Trudgill, DL 1971 Effects of amino acids on the reproduction of Heterodera rostochiensis. Nematologica 17: 495-500. [Non-patent document 8] Crow, WT, Cuda, JP, Stevens, BR 2009. Efficacy of Methionine Against Ectoparasitic Nematodes on Golf Course Turf. Journal of Nematology, 41: 217-220. [Non-Patent Document 9] Epstein, E. 1973. Effect of pretreatment with some amino acids and amino acids antimetabolites on Longidorus africanus infected and non-infected Bidens triparitita. Nematologica 18: 555-562. [Non-Patent Document 10] Talavera, M., and Mizukubo, T. 2005. Effects of DL-methionine on hatching and activity of Meloidogyne incognita eggs and juveniles. Pest Management Science 61: 413-416. Summary of the Invention [Problem to be solved by the invention]

[0011] An object of the present disclosure is to provide a composition for controlling nematodes and a method for controlling nematodes that exhibit high control activity even when the application rate of methionine is small. [Means for solving the problem]

[0012] The inventors have found that when L-methionine is applied, a nematode control effect can be obtained even at low concentrations, and have completed the nematode control composition and control method of the present disclosure.

[0013] A first aspect of the present disclosure is A composition for controlling nematodes, comprising methionine, The methionine comprises more than 50% by weight of L-methionine based on the total weight of the methionine.

[0014] A second aspect of the present disclosure is A method for controlling nematodes, comprising: 1000m of field 2 methionine in an amount of 5 to 80 kg per plant; The methionine comprises more than 50% by weight of L-methionine based on the total weight of the methionine. [Effects of the Invention]

[0015] The nematode-controlling composition of the present disclosure contains methionine, and since the methionine contains L-methionine, it can control nematodes safely, inexpensively, and effectively. Furthermore, the nematode-controlling composition of the present disclosure has a low environmental impact and can be easily applied, thereby contributing to the promotion of sustainable agriculture.

[0016] The nematode control method of the present disclosure is carried out in a field 10a (1000 m 2 By applying 5 to 80 kg of methionine per 1000 stalks, and by including L-methionine in the methionine, nematodes can be controlled safely, inexpensively, and effectively compared to conventional control methods. Furthermore, the method of the present disclosure has the advantage that, since the amount of methionine applied is smaller than that of conventional methods, it is not toxic to plants and can be carried out during the cultivation period. Furthermore, the method of the present disclosure has a small environmental impact and is simple, so it can contribute to the spread of sustainable agriculture. [Brief explanation of the drawings]

[0017] [Figure 1] The nematode-inhibiting effect of an aqueous methionine solution was evaluated using the method described in Example 1. The results are shown in terms of the relationship between methionine concentration and survival rate. (A) shows the results after 1 day, and (B) shows the results after 4 days. [Figure 2] The nematode-inhibiting effect of an aqueous methionine solution was evaluated using the method described in Example 1. (A) shows the result at 2500 ppm, and (B) shows the result at 250 ppm. [Figure 3] The following shows the results of evaluating the effect of the ratio of L- to D-methionine on the inhibitory effect against Meloidogyne incognita, using the method described in Example 2. (A) shows the results for 300 ppm, (B) for 600 ppm, and (C) for 1200 ppm. [Figure 4] The nematode-inhibiting effect of an aqueous methionine solution was evaluated using the method described in Example 4, and the results are shown in terms of the relationship between methionine concentration and survival rate. [Figure 5]1 shows the results of evaluating the inhibitory effect of an aqueous methionine solution on Meloidogyne northernis, using the method described in Example 5. (A) shows the results after 1 day, and (B) shows the results after 4 days. [Figure 6] The inhibitory effect of an aqueous methionine solution on the root-knot nematode Meloidogyne arenae was evaluated using the method described in Example 6. The results are shown in terms of the relationship between methionine concentration and survival rate. (A) shows the results after 3 hours, (B) shows the results after 2 days, and (C) shows the results after 3 days. [Figure 7] The control effects of optical isomers of methionine on Meloidogyne incognita were compared using the method described in Example 7, and the results are shown below. [Figure 8] Photographs of tomato roots collected from the study described in Example 7. (A) are two control tomato roots, (B) are two tomato roots supplemented with 67 ppm D-methionine, and (C) are, from right to left, tomato roots supplemented with 67 ppm, 133 ppm, and 200 ppm D-methionine. [Figure 9] Photographs of tomato roots collected in the test described in Example 7. (A) shows, from the right, roots of tomatoes supplemented with L-methionine at 67 ppm, 133 ppm, and 200 ppm. (B) shows, from the right, roots of tomatoes supplemented with DL-methionine at 67 ppm, 133 ppm, and 200 ppm. [Figure 10] 1 shows the results of evaluating the nematode-suppressing effects of powdered L-methionine and DL-methionine using the method described in Example 11. (A) shows a comparison of the number of root galls, and (B) shows a comparison of the control value. DETAILED DESCRIPTION OF THE INVENTION

[0018] Hereinafter, embodiments of the present disclosure will be described, but the present disclosure is not limited to the following embodiments. Note that duplicated descriptions of identical components may be omitted.

[0019] 1. Composition A first aspect of the present disclosure relates to a composition for controlling nematodes, comprising methionine. The composition of the present disclosure may comprise 20 to 100% by weight, preferably 40 to 100% by weight, and more preferably 60 to 100% by weight of methionine. The composition of the present disclosure may consist solely of methionine. Furthermore, in the composition of the present disclosure, the methionine comprises L-methionine. In one embodiment, the composition of the present disclosure comprises 50 to 100% by weight, preferably 75 to 100% by weight, and more preferably 95 to 100% by weight of L-methionine, based on the total weight of the composition.

[0020] (methionine) Methionine is one of the 20 amino acids that make up proteins and is an essential amino acid. It exists in D-form (D-methionine) and L-form (L-methionine), and when the D- and L-forms exist in equal amounts, it is called a racemic mixture (DL-methionine, DL-form). Methionine is widely used as a human medicine, veterinary medicine, food additive, and feed additive, and is a highly safe substance. Furthermore, it is less expensive than existing pesticides.

[0021] In the composition of the present disclosure, the methionine comprises L-methionine. The methionine comprises more than 50% by weight, preferably 75% by weight or more, more preferably 85% by weight or more, even more preferably 95% by weight or more, and most preferably 99% by weight or more of L-methionine, based on the total weight of methionine. In one embodiment, the methionine comprises up to 100% by weight of methionine. In one embodiment, the methionine may consist solely of L-methionine. By including L-methionine as an active ingredient, the composition of the present disclosure can provide a nematode control composition that is highly safe, inexpensive, and has a low environmental impact.

[0022] L-methionine in the present disclosure may be produced by any method. Examples of methods for producing L-methionine include synthetic methods, enzymatic methods, extraction methods, and fermentation methods. The synthetic method involves isolating L-methionine from a racemic form of methionine chemically synthesized by a known method. The enzymatic method involves converting a precursor to L-methionine through an enzymatic reaction. The extraction method involves isolating L-methionine from a mixture of amino acids obtained by protein degradation. The fermentation method involves selectively producing L-methionine by fermenting a raw material using a microorganism.

[0023] As described in the Examples section, it has been suggested that D-methionine may interfere with the nematode control effect of L-methionine in the composition of the present disclosure. Therefore, in one embodiment, it is desirable that methionine does not contain D-methionine. If present, the amount of D-methionine is desirably less than 50% by weight, preferably 25% by weight or less, more preferably 15% by weight or less, even more preferably 5% by weight or less, and most preferably 1% by weight or less, based on the total weight of methionine. In one embodiment, the composition of the present disclosure does not contain D-methionine.

[0024] (surfactant) The composition of the present disclosure can further contain a surfactant. The inclusion of a surfactant in the composition of the present disclosure can promote penetration of methionine into soil pores and facilitate contact between L-methionine and target nematodes. The composition of the present disclosure can contain 0.1 to 20% by weight, preferably 0.1 to 10% by weight, of the surfactant.

[0025] Surfactants that can be used in the composition of the present disclosure include, for example, nonionic surfactants, anionic surfactants, cationic surfactants, etc. Nonionic surfactants include, but are not limited to, polyoxyethylene alkyl ethers, polyoxyethylene alkylphenyl ethers, sorbitan fatty acid esters, polyoxyethylene sorbitan fatty acid esters, sucrose fatty acid esters, polyoxyethylene castor oil, polyoxyethylene hydrogenated castor oil, alkyl glycosides, etc. Anionic surfactants include alkyl sulfates, alkyl ether sulfates, lignin sulfonates, etc. Cationic surfactants include, for example, quaternary alkyl ammonium salts, etc.

[0026] (Additional Ingredients) The composition of the present disclosure may further contain additional ingredients, such as a bulking agent, a solvent, a pH adjusting agent, a binder, a disintegrant, a physical property improving agent, an antifungal agent, a stabilizer, a colorant, a fragrance, a safener, and the like.

[0027] Examples of fillers include, but are not limited to, talc, bentonite, diatomaceous earth, amorphous silica, clay, attapulgite, calcium carbonate, and other inorganic salts.

[0028] Examples of solvents include, but are not limited to, water, methanol, and ethanol.

[0029] Examples of pH adjusters include, but are not limited to, sodium hydroxide, potassium hydroxide, sodium carbonate, sodium bicarbonate, lactic acid, sodium lactate, phosphoric acid, sodium dihydrogen phosphate, citric acid, and sodium citrate.

[0030] Examples of binders include, but are not limited to, polyvinylpyrrolidone, polyvinyl alcohol, carboxymethylcellulose, sodium carboxymethylcellulose, starch, starch derivatives, sodium acrylates, and fats and oils (e.g., vegetable oils such as soybean oil, palm oil, and corn oil, and animal oils such as lard, fish oil, and butter).

[0031] (Form of composition) The composition of the present disclosure can be in any form. For example, the composition of the present disclosure can be in the form of a solid or liquid that can be directly mixed or sprayed on soil, or in the form of a solid or liquid that can be dissolved in a solvent such as water before use. More specifically, the form of the composition of the present disclosure includes, but is not limited to, dusts, granules, powders, wettable powders, water-soluble powders, emulsions, liquids (including solutions), oils, aerosols, liniments, microcapsules, etc. The composition of the present disclosure is preferably in the form of a dust, granules, dust, powder, wettable powder, or water-soluble powder, and more preferably in the form of a granule, dust, powder, powder, or water-soluble powder.

[0032] (Method of producing the composition) The composition of the present disclosure can be produced by any method known in the art. For example, in the case of a solid form, the composition of the present disclosure can be produced by grinding, mixing, sieving, granulating, or the like, either alone or in combination. In the case of a liquid form, the composition of the present disclosure can be obtained in the form of a solution by, for example, a dissolving process, or in the form of a suspension or emulsion by a dispersing process. In addition, the bulk powder of methionine can be used as the composition of the present disclosure.

[0033] The milling step involves milling bulk methionine powder to a desired particle size by methods known in the art. The milled methionine may be incorporated into the composition of the present disclosure or may be subjected to further processing.

[0034] The blending step involves blending raw or milled methionine with additional ingredients, such as bulking agents, by methods known in the art. The blend of methionine and additional ingredients may be a composition of the present disclosure, or the blend may be subjected to further processing steps.

[0035] The classification step is a step of separating methionine or a raw material containing methionine according to the particle size of the powder or particles. Classification methods are broadly classified into dry classification and wet classification, both of which are known in the art. The methionine or a composition containing methionine obtained by the classification step may be used as the composition of the present disclosure or may be further subjected to another step.

[0036] The granulation process is a process of processing methionine or a mixture of methionine and additional ingredients into a desired particle size. Granulation methods are broadly classified into wet granulation and dry granulation, and are known in the art. The obtained granules may be used as the composition of the present disclosure or may be further subjected to another process.

[0037] The dissolving step is a step of dissolving a raw material containing methionine in a solvent. The raw material dissolved in the solvent may consist of methionine alone or may contain additional components. The dissolving step can also be used in combination with the above-mentioned grinding, mixing, and granulation steps. For example, in the dissolving step, methionine bulk powder may be dissolved in a solvent, or a raw material containing methionine that has been processed by at least one of grinding, mixing, and granulation steps may be dissolved in a solvent. The resulting solution may be used as a composition of the present disclosure or may be further subjected to another step.

[0038] The dispersion step is a step in which methionine or a raw material containing methionine in a solid or liquid form is dispersed in a solvent, oil, or the like. The methionine or a raw material containing methionine may be obtained through the above-mentioned steps of grinding, mixing, classification, granulation, or the like. The dispersion step can be carried out by any method known in the art. The obtained dispersion may be used as the composition of the present disclosure or may be further subjected to another step.

[0039] The above-described production methods are merely examples, and the production method of the composition of the present disclosure is not limited to these. Additional components and solvents in each step are as described in the section (Additional Components).

[0040] (Nematodes) Nematodes are a general term for animals belonging to the phylum Nematoda, and are slender worms with body lengths of 0.1mm to 1000mm. Nematodes are found in large numbers in all biospheres on Earth and are divided into free-ranging and parasitic species. In the agricultural sector, a group of parasitic species known as plant-parasitic nematodes (also known as harmful nematodes or plant-pathogenic nematodes) are problematic because they cause agricultural damage.

[0041] The composition of the present disclosure can be suitably used to control plant parasitic nematodes, more specifically, plant parasitic nematodes living in soil. Nematodes that can be controlled by the composition of the present disclosure include, but are not limited to, root-knot nematodes, root-lesion nematodes, and cyst nematodes. Examples of root-knot nematodes include Meloidogyne incognita, Meloidogyne nigricans, Meloidogyne arenarinensis, and Meloidogyne javanica. Examples of root-lesion nematodes include Meloidogyne nigricans, Meloidogyne malvaceae, Meloidogyne walnuti, Meloidogyne kumamotoi, and Meloidogyne cornii. Examples of cyst nematodes include Meloidogyne gracilis, Meloidogyne leucopeniae, Meloidogyne glycerin, Meloidogyne glycerin, Meloidogyne glycerin, and Meloidogyne glycerin. Other examples include the nematode, the nematode, and the false nematode.

[0042] (How to use) The composition of the present disclosure can be applied to soil by any method known in the art. The composition of the present disclosure may be applied before or after planting of the plant. Alternatively, the composition may be applied both before and after planting of the plant. When the composition of the present disclosure is applied before planting, it is preferable to apply it within 20 days, preferably within 15 days, and more preferably within 10 days before planting of the plant. Furthermore, it is even more preferable that the soil to which the composition of the present disclosure has been applied be uniformly mixed. When the composition of the present disclosure is applied after planting, it is preferable to apply it 20 to 60 days, preferably 25 to 50 days, more preferably 30 to 40 days, and most preferably 30 days after planting. It is also preferable that the soil to which the composition of the present disclosure has been applied be uniformly mixed. Note that, as used herein, the term "plant" includes plants cultivated in fields, i.e., crops, as well as useful plants other than crops, such as lawns and shrubs. As used herein, the term "useful plant" refers to plants that are beneficial to human life.

[0043] The composition of the present disclosure was applied to field 10a (1000 m 2 The amount of L-methionine applied per 1000 sq m of soil (including the soil) is preferably 5 to 40 kg, more preferably 7.5 to 30 kg, and even more preferably 10 to 20 kg. This range is preferable because it does not inhibit plant growth and effectively controls nematodes. In this specification, the term "field" includes not only a place where crops are grown, but also a place where useful plants other than crops are grown.

[0044] In addition, the composition of the present disclosure may be mixed with a surfactant at the time of application, or may be dissolved or dispersed in a solvent or oil. In this case, the composition of the present disclosure may be in a solid or liquid form. The surfactant, solvent, and oil are as described in the (Additional Components) section.

[0045] The composition of the present disclosure contains L-methionine as an active ingredient, enabling nematode control with high safety, low cost, and effectiveness. Furthermore, the composition of the present disclosure requires a smaller amount of methionine than conventional compositions, and therefore has the advantage of not inhibiting plant growth and allowing application during the cultivation period. Furthermore, the composition of the present disclosure has a low environmental impact and can be easily applied, contributing to the spread of sustainable agriculture.

[0046] 2. Nematode control methods A second aspect of the present disclosure relates to a method for controlling nematodes. The method of the present disclosure is carried out in a field 10a (1000 m 2 The method includes applying methionine in an amount of 5 to 80 kg, preferably 7.5 to 60 kg, and more preferably 10 to 40 kg per 10 ...

[0047] In the methods of the present disclosure, methionine can be applied by any method known in the art. For example, methionine may be applied to soil in powdered or granular solid form, or may be applied after dissolving it in a solvent. Methionine or a solution thereof may be mixed with a surfactant at the time of application. Alternatively, methionine formulated by a method known in the art may be applied. Methods for formulating methionine are as described in the section "1. Composition" (Methionine Preparation Method), and surfactants are as described in the section "Additional Components."

[0048] In the methods of the present disclosure, methionine may be applied before or after planting of the plants. In one embodiment, the methods of the present disclosure involve applying methionine within 20 days, preferably within 15 days, and more preferably within 10 days before planting. In another embodiment, the methods of the present disclosure involve applying methionine 20 to 60 days, preferably 25 to 50 days, more preferably 30 to 40 days, and most preferably 30 days after planting. In yet another embodiment, the methods of the present disclosure involve applying methionine before planting and applying methionine after planting.

[0049] Nematodes primarily live at a depth of 10 to 20 cm from the soil surface. Therefore, in one embodiment, the method of the present disclosure preferably includes uniformly mixing the soil after applying methionine. The depth of the mixed soil can be 20 cm, more preferably 15 cm, from the soil surface. Mixing the soil after applying methionine can effectively reduce nematode damage to plants.

[0050] The method of the present disclosure may further include applying a surfactant. Surfactants that can be used in the method of the present disclosure are as described in the section "1. Composition" (Surfactant). In the method of the present disclosure, the surfactant may be applied before or after methionine. Alternatively, methionine and a surfactant may be combined and applied simultaneously.

[0051] The method of the present disclosure can control nematodes safely, inexpensively, and effectively. Furthermore, the method of the present disclosure has the advantage that it requires a lower amount of methionine than conventional methods, is not toxic to plants, and can be carried out during the cultivation period. Furthermore, the method of the present disclosure has a low environmental impact and is simple, so it can contribute to the spread of sustainable agriculture. [Example]

[0052] The present disclosure will be specifically described below with reference to examples and comparative examples, but the present disclosure is not limited to the following examples.

[0053] Example 1 Comparison of the nematode-inhibiting effect of methionine aqueous solution with optical isomers (1) Aqueous solutions of D-, L-, and DL-methionine at various concentrations were contacted with Meloidogyne incognita, and the inhibitory effect of each optical isomer on the nematode was evaluated.

[0054] 1. Test Method (1) Meloidogyne incognita (MAFF108258 strain) was added to tap water to prepare a nematode suspension at 250 nematodes / mL, which was then stored at 10°C until use. Six days after collecting egg capsules, newly hatched larvae were collected and immediately used to prepare the suspension. (2) D-methionine (Tokyo Chemical Industry Co., Ltd., purity >99.0%), L-methionine (Asuka Animal Health Co., Ltd., purity 99.6%), and DL-methionine (Asuka Animal Health Co., Ltd., purity 99.5%) were each dissolved in purified water to prepare aqueous methionine solutions with concentrations of 0.5 ppm, 5 ppm, 50 ppm, 500 ppm, and 5000 ppm. (3) 100 μL of nematode suspension was poured into each well of a 96-well plate (round-bottom, water-repellent coating) using a glass pipette. Additionally, 100 μL of methionine solution of each concentration was added to each well. Therefore, the methionine concentrations when the nematodes were immersed were 0.25 ppm, 2.5 ppm, 25 ppm, 250 ppm, and 2500 ppm, respectively. 100 μL of purified water was added to the control (0 ppm, CTL). The number of experiments was n = 4. (4) One, three, four, and seven days after immersion in the methionine solution, the number of surviving nematodes was counted under transmitted light using a stereomicroscope. Nematodes that were moving and those with bent bodies were considered to be alive. Nematodes that were straight were considered to be dead.

[0055] 2.Results The results are shown in Tables 1-2 and Figures 1-2. Table 1 and Figure 1 show the relationship between the concentration of each isomer of methionine and the survival rate of nematodes after 1 day and 4 days. Table 2 and Figure 2 show the change in survival rate of nematodes over time for 2500 ppm and 250 ppm. Each value is an average value.

[0056] [Table 1]

[0057] [Table 2]

[0058] Contrary to expectations based on the prior art, the results show that L-methionine exhibited concentration-dependent contact toxicity to Meloidogyne incognita after 1 day of immersion, whereas the D- and DL-methionines did not. However, after 4 days of immersion, both the D- and DL-methionines exhibited concentration-dependent contact toxicity. At 250 ppm, the survival rates of nematodes exposed to the L- and DL-methionines showed similar trends over time, reaching approximately 40% after 4 days but not reaching 0%. At 2500 ppm, the survival rate of the L-methionine reached 0% after 4 days, whereas the D- and DL-methionines remained around 60% after 4 days and remained above 0% even after 7 days. These results demonstrate that the L-methionine has superior nematode inhibitory effects compared to the D- and DL-methionines.

[0059] In addition, from the approximate formula of the graph in Figure 1, the LD for each optical isomer of methionine is 50 For L-methionine after 4 days, the LD 50 On the other hand, the LD of D-methionine and DL-methionine after 4 days was estimated to be 60 ppm (corresponding to a field treatment amount of 3 kg / 10 a). 50The calculated values ​​of DL-methionine and LD-methionine were 19,000 ppm (corresponding to a field treatment amount of 950 kg / 10 a) and 1,100 ppm (corresponding to a field treatment amount of 55 kg / 10 a), respectively. Half of DL-methionine was L-methionine, and the LD-methionine 50 Considering that the concentration of LD in the DL form was 60 ppm, 50 The concentration of the D-isomer should be 120 ppm, twice that of the L-isomer, but in reality it was about nine times that amount. This suggests, without being bound by theory, that the D-isomer may inhibit the inhibitory effect of the L-isomer on nematodes.

[0060] The aqueous solution concentration (ppm) was converted to the amount of treatment in the field as follows: Since the rotary tillage depth is approximately 15 cm, if the depth of the field to be mixed and treated is 15 cm, then 10 a (1000 m 2 ) is 150,000 kg. As soil also contains a lot of air, if we assume its density to be 1 kg / L, the volume will be 150,000 L. Furthermore, the weight moisture content of the black soil that is common in Japan is around 30%, meaning that water accounts for approximately one-third of the soil weight. Therefore, the soil volume per 10 a (1000 m) of field is calculated by multiplying the concentration of the methionine solution (ppm = mg / L) by the soil volume of 150,000 L and dividing the result by 3. 2 ) was used as the processing amount per

[0061] Example 2: Effect of the ratio of L-methionine and D-methionine on the inhibition of Meloidogyne incognita The results of Example 1 suggested that the D-form of methionine may inhibit the inhibitory effect of the L-form on nematodes. Therefore, the mixing ratio of the L-form to the D-form was gradually changed to evaluate the effect of the D-form on the nematode inhibitory effect of the L-form.

[0062] 1. Test Method (1) Meloidogyne incognita (strain MAFF108258) was added to tap water to prepare a nematode suspension at 250 nematodes / mL, which was then stored at 10°C until use. (2) A total of 0.24 g of L-methionine (Tokyo Chemical Industry Co., Ltd., purity >99.0%) and D-methionine (Tokyo Chemical Industry Co., Ltd., purity >99.0%) were dissolved in 100 mL of purified water at weight ratios of 100:0, 99:1, 95:5, 85:15, 75:25, and 50:50, respectively, to prepare six 2400 ppm methionine solutions ranging from 100 wt% to 50 wt% L-methionine to total methionine. A 1200 ppm solution was prepared by diluting 10 mL of this 2400 ppm solution with 10 mL of purified water. Furthermore, a 600 ppm methionine solution was prepared by diluting 5 mL of the 2400 ppm solution with 15 mL of purified water. (3) 100 μL of nematode suspension was poured into each well of a 96-well plate (round-bottom, water-repellent) using a glass pipette. Additionally, 100 μL of methionine solution of each concentration was added to each well. Therefore, the methionine concentrations when the nematodes were immersed were 300 ppm, 600 ppm, and 1200 ppm, respectively. 100 μL of purified water was added to the control (0 ppm, CTL). The number of experiments was n = 4. (4) Immediately after immersion in the methionine solution (day 0), and 1, 3, and 6 days later, the number of surviving nematodes was counted under transmitted light using a stereomicroscope. The number of surviving nematodes was determined in the same manner as in Example 1, 1. Test Method (4).

[0063] The results are shown in Tables 3 to 5 below and in FIG.

[0064] [Table 3]

[0065] [Table 4]

[0066] [Table 5]

[0067] Tables 3 to 5 and Figure 3 show that the nematode-inhibiting effect increases with increasing L-methionine content. Furthermore, all aqueous solutions containing 75 to 100% L-methionine by weight exhibited higher nematode-inhibiting effects than those containing 50% L-methionine by weight (i.e., DL-methionine). In particular, aqueous solutions containing 99% and 100% L-methionine by weight exhibited high nematode-inhibiting effects at all concentrations, with the nematode survival rates after 6 days being nearly 0% at 600 ppm (corresponding to a field treatment rate of 30 kg / 10 a) and 1200 ppm (corresponding to a field treatment rate of 60 kg / 10 a). These results demonstrate that the composition of the present disclosure, containing more than 50% L-methionine by weight based on the total weight of methionine, can provide excellent nematode-inhibiting effects, and that this effect is enhanced with increasing L-methionine content.

[0068] Example 3 Comparison of the nematode-inhibiting effect of methionine aqueous solution with optical isomers (2) The results of Example 1 showed that in the case of L-methionine, the survival rate of nematodes varied significantly between 250 ppm and 2500 ppm. Therefore, the concentration of the methionine solution was changed and tests were conducted in the same manner as in Example 1 to evaluate in more detail the relationship between the methionine concentration and the nematode-inhibiting effect.

[0069] 1. Test Method The test was carried out in the same manner as in Example 1, except that aqueous methionine solutions were prepared at concentrations of 600 ppm, 1200 ppm, 1800 ppm, 2400 ppm, and 5000 ppm.

[0070] 2.Results The average values ​​of the obtained results are shown in Tables 6 to 8 below.

[0071] [Table 6]

[0072] [Table 7]

[0073] [Table 8]

[0074] Looking at the results after 4 days in Table 6, it was found that in the case of L-methionine, 900 ppm was as effective as 2500 ppm. 2 This corresponds to 45 kg of L-methionine per 10 a. Furthermore, it was shown that L-methionine has sufficient nematode suppression effects even at 300 ppm (equivalent to 15 kg / 10 a). On the other hand, with D-methionine and DL-methionine, the survival rate after 4 days exceeded 50% at most concentrations. These results indicate that L-methionine has superior nematode suppression effects compared to D-methionine and DL-methionine, even at lower concentrations.

[0075] Example 4 Comparison of the nematode-inhibiting effect of methionine aqueous solution with optical isomers (3) Examples 1 to 3 demonstrated the inhibitory effect of L-methionine when it was in contact with nematodes for a long period of time. Therefore, tests were conducted with a shorter contact time to evaluate the inhibitory effect of L-methionine on nematodes (Meloidogyne incognita) after short-term contact.

[0076] 1. Test Method The test was carried out in the same manner as in Example 1, except that the concentrations of the methionine aqueous solution were changed to 0 ppm, 300 ppm, 600 ppm, 1200 ppm, 1800 ppm, 2400 ppm, and 4800 ppm, and the test time was changed to 4 hours. The test was carried out in duplicate.

[0077] 2.Results The results are shown in Table 9 below and in Figure 4. Results are average values.

[0078] [Table 9]

[0079] The results showed that 4 hours after contact with the methionine aqueous solution, the survival rate of the L-form decreased in a concentration-dependent manner. Furthermore, at all concentrations, the survival rate of nematodes was lower for the L-form than for the D- and DL-forms. These results indicated that the L-form has a superior nematode suppression effect at all concentrations compared to the D- and DL-forms. The logarithmic approximation line of the L-form (y = -16.28ln(x) + 127.2, R 2 =0.66), the LD of the L-form after 4 hours 50 was calculated to be 115 ppm. 2 ) is equivalent to 6 kg.

[0080] Example 5 Evaluation of the inhibitory effect of methionine on Meloidogyne truncatula Using Meloidogyne nigricans as the nematode, the inhibitory effects of each optical isomer of methionine were evaluated.

[0081] 1. Test Method The test was conducted in the same manner as in Example 1, except that the concentrations of the prepared methionine aqueous solutions were 300 ppm, 600 ppm, 1200 ppm, and 1800 ppm, and that Meloidogyne nigra (MAFF108260 strain) was used as the nematode. The number of surviving nematodes was counted 1 day and 4 days after the start of the test.

[0082] 2.Results The results are shown in Table 10 below and in Figure 5. Results are average values.

[0083] [Table 10]

[0084] After 1 day, only L-methionine showed an inhibitory effect against Meloidogyne nigra. After 4 days, L-methionine showed excellent inhibitory effect against Meloidogyne nigra. On the other hand, D-methionine and DL-methionine showed no inhibitory effect after 1 day, and after 4 days, a decrease in viability was observed, but the effect was slight. These results suggest that L-methionine is effective against a wide range of root-knot nematodes, not just Meloidogyne incognita.

[0085] Example 6 Evaluation of the inhibitory effect of methionine on the root-knot nematode Using the root-knot nematode Meloidogyne arenaria as the nematode, the control effect of each optical isomer of methionine was evaluated.

[0086] 1. Test Method The optical isomers of methionine used were D-methionine (Tokyo Chemical Industry Co., Ltd., purity >99.0%), L-methionine (Tokyo Chemical Industry Co., Ltd., purity >99.0%), and DL-methionine (Tokyo Chemical Industry Co., Ltd., purity >99.0%). The test was conducted in the same manner as in Example 1, except that the concentrations of the prepared methionine aqueous solutions were 300 ppm, 600 ppm, 1200 ppm, 1800 ppm, 2400 ppm, and 4800 ppm, and the root-knot nematode Meloidogyne arenaria (strain MAFF108262) was used as the nematode. The number of surviving nematodes was counted 3 hours, 2 days, and 3 days after the start of the test.

[0087] 2.Results The results are shown in Table 11 and FIG.

[0088] [Table 11]

[0089] As shown in Table 11 and Figure 6, 3 hours after immersion, the D- and DL-methionine forms exhibited high nematode survival rates at all concentrations. On the other hand, the L-methionine exhibited a high nematode-inhibiting effect, and this effect increased roughly in proportion to the concentration. Even after 2 and 3 days, the survival rates of nematodes treated with the D-methionine form remained high. In contrast, the survival rates of nematodes treated with the DL-methionine form decreased in a concentration-dependent manner up to 1200 ppm, but at 2400 ppm, the survival rates recovered and remained high. Without being bound by theory, it is possible that the presence of high concentrations of the D-methionine form counteracted the inhibitory effect of the L-methionine form against root-knot nematodes. On the other hand, after 2 and 3 days, the survival rates of nematodes treated with the L-methionine form remained low at all concentrations. These results demonstrate that the composition of the present disclosure also exhibits a high inhibitory effect against root-knot nematodes.

[0090] Example 7 Comparison of the control effects of optical isomers of methionine on Meloidogyne incognita D-, L-, and DL-methionine were added at various concentrations to soil inoculated with Meloidogyne incognita, and the effect on the degree of clubroot damage in tomatoes was evaluated.

[0091] 1. Test Method (1) Soil for growing sweet potato root-knot nematodes (MAFF108258 strain, purchased from the National Agriculture and Food Research Organization Gene Bank), commercially available black soil, and horticultural seedling soil (manufactured by Hokusan Co., Ltd.) were mixed in a 1:1:1 ratio to prepare nematode-contaminated soil. (2) D-methionine (Tokyo Chemical Industry Co., Ltd., purity >99.0%), L-methionine (Asuka Animal Health Co., Ltd., purity 99.6%), and DL-methionine (Asuka Animal Health Co., Ltd., purity 99.5%) were each dissolved in ion-exchange water to a concentration of 0.5% (w / v) to prepare a 0.5% methionine aqueous solution. (3) 8 mL, 16 mL, and 24 mL of 0.5% methionine solution were added to 600 mL of nematode-contaminated soil and mixed. 2This corresponds to 10 kg (67 ppm), 20 kg (133 ppm), and 30 kg (200 ppm) of methionine per 10 ... (4) A portion of the soil prepared in step (3) was removed and the number of nematodes in the soil was measured by separating them using the Bellman method. First, a paper plate was placed in a glass container, and 10 g of soil was placed on top of it. The mixture was left to stand for three days to separate the nematodes into the glass container. The settled nematode larvae were collected and counted using a plankton counting slide. (5) The remaining soil was filled into 600 mL seedling pots. 24 days after sowing, one cherry tomato (variety: Regina, Sakata Seed) was planted in each pot. The pots were placed in a glasshouse and grown for 21 days (maximum temperature 35°C, average temperature 28°C). During growth, the soil was watered once a day to prevent it from drying out. The number of tests was n=3. 21 days after growth began, the roots were removed from the pots. The pots were rinsed with water in the shower to remove the soil, and the degree of root gall damage was confirmed visually for each condition.

[0092] 2. Evaluation Method The degree of root club damage was evaluated using the Zeck scale (Zeck, WM (1971): Pflanzenschutz-Nachichten. Bayer AG, 24, 141-144.) and the average and standard deviation (SD) of the scores obtained for the three plants were calculated. 0: No root galls are observed. 1: With careful observation, several small galls can be seen. Several small galls similar to those in 2:1 can be easily seen. 3: There are many small galls, some of which are fused together. Root function is mostly intact. 4: Numerous small galls and some large galls. Most of the roots are functioning. 5: 25% of the roots are heavily clubbed and non-functional. 6: 50% of the roots are heavily clubbed and non-functional. 7: 75% of the roots are heavily galled and the root regeneration ability is lost. 8: There are no healthy roots, and the plant's nutrient absorption is hindered. The stems and leaves are still green. 9: The root system is completely covered with galls and is rotting. The plant is dying. 10: Plants and roots die.

[0093] 3.Results The results are shown in Tables 12 and 13 below and in Figure 7. Photographs of the collected roots are shown in Figures 8 and 9.

[0094] [Table 12]

[0095] [Table 13]

[0096] Regarding nematode density, L-methionine and DL-methionine produced significantly lower nematode densities than D-methionine at any methionine dose, indicating that the nematode-inhibitory effect of D-methionine is significantly lower than that of the L- and DL-methionine forms.

[0097] At 200 ppm, both methionine compounds were effective in controlling root club damage compared to the control. At 133 ppm, L- and DL-methionine were highly effective, but D-methionine was less effective than L- and DL-methionine. At 67 ppm, both methionine compounds were lower than the control, but L-methionine was significantly more effective than D- and DL-methionine. These results suggest that L-methionine exerts a greater nematode control effect at lower concentrations than D- and DL-methionine. In particular, 67 ppm L-methionine suppressed root club damage to the same extent as 133 ppm DL-methionine, suggesting that the use of L-methionine for nematode control can reduce the amount of DL-methionine used compared to previously suggested methods, resulting in cost savings.

[0098] Example 8 Comparison of the control effects of optical isomers of methionine on root-knot nematodes D- and L-methionine were added to soil inoculated with the root-knot nematode Meloidogyne arenae, and the effect on the survival rate in the soil was evaluated.

[0099] 1. Test Method (1) Nematode nematode (MAFF108262 strain, obtained from the National Agriculture and Food Research Organization Genebank) was propagated on tomatoes planted in Andosol. The soil was sieved with a mesh size of 2.5 mm and the roots were removed. (2) A portion of the soil prepared in step (1) was removed and the number of nematodes in the soil was measured by separating them using the Bellman funnel method. First, 20 g of soil was placed on a mesh dish lined with paper, immersed in a glass funnel filled with water, and left to stand for 3 days, after which the nematodes were separated into vials attached to the base of the glass funnel. The nematode larvae that settled in the vials were collected and counted using a plankton counting slide. (3) An appropriate amount of the sieved soil from step (1) was mixed with commercially available black soil adjusted to a moisture content of 33% to prepare nematode-infested soil with an initial density of 2.5 nematodes per gram of soil. (4) 1 g each of D-methionine (Tokyo Chemical Industry Co., Ltd., purity >99.0%), L-methionine (Tokyo Chemical Industry Co., Ltd., purity >99.0%), and DL-methionine (Tokyo Chemical Industry Co., Ltd., purity >99.0%) was dissolved in 50 mL of purified water to prepare a 2% methionine solution. This was further diluted 10-fold to prepare a 0.2% methionine solution. (5) Treatment concentrations were 100 mg / L (equivalent to a field treatment volume of 15 kg / 10 a) and 200 mg / L (field treatment volume of 30 kg / 10 a). For the 100 mg / L (15 kg / 10 a) treatment, 30 mL of 0.2% methionine solution was sprayed onto 600 mL of nematode-infested soil, followed by 30 mL of water. For the 200 mg / L (30 kg / 10 a) treatment, 60 mL of 0.2% methionine solution was sprayed onto 600 mL of nematode-infested soil. The control (CTL) treatment consisted of 60 mL of water. The soil was mixed by rotating it in an inflated plastic bag. The resulting soil was placed in a sealed plastic bag and left at 25°C for 3 days to simulate the conditions of a vinyl mulch treatment. (6) Nematodes were isolated from the soil using the Bellman funnel method, as in step (2), and the number of nematodes in the soil was measured. The number of tests was n = 3 (soils 1 to 3).

[0100] 3.Results The results are shown in Table 14. The control value was calculated using the following formula. Control value (%) = (1 - average number of nematodes under each condition / average number of nematodes in the control) x 100

[0101] [Table 14]

[0102] L-methionine showed a higher control value than D-methionine. In particular, the nematode density was 0 at a treatment concentration of 30 kg / 10a of L-methionine. On the other hand, the control value was lower with D-methionine, and at a treatment concentration of 15 kg / 10a, the control value was negative. These results indicate that L-methionine has a higher inhibitory effect against the root-knot nematode than D-methionine.

[0103] Example 9 Comparison of the inhibitory effects of optical isomers of methionine on root-knot nematode damage in sweet potatoes Since the demand for nematode control agents is particularly high in sweet potato cultivation, we added L- and DL-methionine to soil inoculated with the sweet potato root-knot nematode and evaluated their effect on the severity of root club damage in sweet potatoes.

[0104] 1. Test Method (1) Meloidogyne incognita (MAFF108258 strain, obtained from the National Agriculture and Food Research Organization Genebank) was propagated on tomatoes planted in andosol. The soil was passed through a 2.5 mm mesh sieve to remove the roots. (2) Nematodes were isolated using the same procedure as the Bellman funnel method described in step (2) of Example 8, and the number of individuals was counted using a plankton counting slide. (3) Test nematode-contaminated soil was prepared in the same manner as in Procedure (3) of Example 8. The initial density of nematodes was 1.25 nematodes per gram of soil. (4) 0.9 g each of L-methionine (Tokyo Chemical Industry Co., Ltd., purity >99.0%) and DL-methionine (Tokyo Chemical Industry Co., Ltd., purity >99.0%) powder was mixed with 99.1% black soil to prepare soil containing 9% methionine. (5) The treatment concentration was 100 mg / L (equivalent to a field treatment rate of 15 kg / 10 a). 100 g of soil containing 9% methionine was added to 9 L of nematode-infected soil, and the mixture was mixed by rotating it in an air-inflated plastic bag. (6) Nematode-infested soil containing the L- and DL-methionine was filled into a 3-L planter, and a single sweet potato vine (variety: Takakei 14) was planted in each. The control was an untreated (CTL) plant, using soil without methionine. The number of experiments was n = 3 (plants 1 to 3). The planters were placed in a glasshouse and grown for 52 days (maximum temperature 35°C, average temperature 28°C). During growth, the soil was watered once a day to prevent the surface from drying out. (7) 52 days after the start of growth, the roots were removed from the pots. The soil was removed by rinsing in the shower, and the vines and tubers were removed from the roots. The washed roots were stored in a freezer at -20°C until the number of root galls was counted. The thawed roots were cut into 5 mm lengths, suspended in water, transferred to a tea strainer, and squeezed to remove the water. The weight (g) of the entire roots was measured, and 2 g of each was taken to count the number of root galls and egg sacs. Egg sacs estimated to be present based on traces of detachment remaining on the root galls were also included. When two or more egg sacs or their detachment traces were found per gall, the number of root galls and egg sacs was equal to the number of egg sacs. The number of root galls and egg sacs per plant was calculated by multiplying the number of root galls and egg sacs per 2 g by the weight (g) of the entire roots and then dividing by 2.

[0105] 3.Results The results are shown in Tables 15 and 16. The control value was calculated using the following formula. Control value (%) = (1 - average number of galls or egg sacs / average number of galls or egg sacs in the control group) x 100

[0106] [Table 15]

[0107] [Table 16]

[0108] In sweet potatoes treated with DL-methionine, the number of galls and egg sacs was equivalent to that of CTL, resulting in a negative control value. In contrast, the number of galls and egg sacs was reduced in sweet potatoes treated with L-methionine, and the control value was higher than that of DL-methionine. These results indicate that L-methionine can provide nematode suppression effects in sweet potatoes compared to DL-methionine.

[0109] Example 10: Comparison of nematode suppression effects between L-methionine powder and aqueous solution L-methionine was applied to soil in different forms and its effect on nematode suppression was evaluated.

[0110] 1. Test Method (1) Nematode-contaminated soil was prepared by mixing sweet potato root-knot nematodes (strain MAFF108258) with commercially available sterilized andosol to a nematode density of 20 nematodes / 20 g of soil. (2) Nematode-contaminated soil was treated with L-methionine under the following conditions A to C. The control (CTL) was soil that had not been treated with L-methionine. (A: Powder mixing treatment) Four grams of sand containing 100-fold diluted L-methionine was mixed with 600 mL of nematode-infested soil to achieve a concentration of 67 ppm L-methionine (equivalent to a field treatment rate of 10 kg / 10 are). Water was added to the mixture to adjust the soil moisture content to 32%, and the mixture was placed in a sealed plastic bag and left at 25°C for three days. Four days after mixing with L-methionine, the soil was filled into pots and used to grow tomatoes. (B: Aqueous solution mixing treatment) L-methionine was dissolved in ion-exchange water to prepare a 0.5% methionine solution. 8 mL of this methionine solution was mixed with 600 mL of nematode-infested soil to adjust the L-methionine concentration to 67 ppm. Water was added to the mixture to adjust the soil moisture content to 32%, and the mixture was placed in a sealed plastic bag and left at 25°C for 3 days. Four days after mixing with L-methionine, the soil was filled into pots and used to grow tomatoes. (C:Irrigation process) 600 mL of nematode-infested soil was filled into a pot. 8 mL of a 0.5% methionine solution was diluted with water to 50 mL and sprayed onto the soil surface with an electric sprayer. The next day and the day after, 50 mL of water was sprayed onto the soil surface in the same manner. (3) One cherry tomato (variety: Regina) plant was planted in each pot prepared in step (2) 31 days after sowing and grown for 24 days in a constant temperature room at 25°C under LD light for plant growth. After 24 days, the roots were removed from the pot, the soil was washed off with a shower, and the number of root galls was counted under a stereomicroscope. Conditions A to C were run in triplicate, and the control was run in quadruplicate.

[0111] 2.Results The results are shown in Table 17. The number of root galls is the average, and the ratio to CTL indicates the ratio (percentage) of the number of root galls under each condition to the number of root galls in the control. The control titer is the value obtained by subtracting the ratio to CTL from 100%.

[0112] [Table 17]

[0113] Under all conditions, L-methionine showed superior inhibitory effects compared to the control, but particularly high inhibitory effects were observed under conditions A (powder-mixed treatment) and B (aqueous solution-mixed treatment).

[0114] Example 11 Evaluation of the nematode suppression effect of L-methionine The effect of powdered L-methionine on root club suppression was evaluated by varying the amount applied to the soil. Similar tests were also conducted with DL-methionine to compare the inhibitory effects.

[0115] 1. Test Method (1) The sweet potato root-knot nematode (MAFF108258 strain) was propagated in cherry tomatoes (variety: Regina) in a planter filled with andosol. The soil in which the sweet potato root-knot nematodes had propagated was diluted with commercially available sterilized andosol to prepare nematode-contaminated soil with a nematode density of 20 nematodes / 20g of soil. (2) L-methionine powder was diluted 100-fold with sand, and 3 g and 4 g of sand were mixed with 600 mL of nematode-infested soil. The L-methionine concentrations were 50 ppm and 67 ppm (equivalent to 7.5 kg and 10 kg per 10 are of soil, respectively, designated "L7.5" and "L10"). For comparison, DL-methionine powder was mixed with 600 mL of soil to a concentration of 67 ppm (DL10). Control soil (CTL) contained no methionine. The soil was placed in a plastic bag, sealed, and left undisturbed for 3 days. (3) Four days after mixing the methionine with the soil, the pots were filled with each soil. Thirty-one days after sowing, one cherry tomato (variety: Regina) plant was planted in each pot and grown for 24 days in a constant temperature room at 25°C under LED plant growth lights. After 24 days, each root was removed from the pot, the soil was washed off with a shower, and the number of root galls was counted under a stereomicroscope. The experiment was conducted on n = 3 (n = 4 for CTL only).

[0116] 2.Results The average number of galls under each condition is shown in Table 18 and Figure 10. In addition, the control value for each condition was calculated from the obtained number of galls. The formula for calculating the control value is shown below. Figure 10 shows the number of galls and the control value as a graph. Control value (%) = (1 - number of galls under each condition / number of galls under the control) x 100

[0117] [Table 18]

[0118] The number of root galls was lowest for L-methionine at 67 ppm, followed by 50 ppm. The root gall control value exceeded 70%. These results suggest that L-methionine exerts excellent nematode control effects at low concentrations. On the other hand, at 67 ppm, DL-methionine only achieved a control value of 23%. This suggests that lower concentrations of DL-methionine do not provide sufficient control.

Claims

1. A composition for controlling nematodes in soil, comprising methionine, the methionine contains 95% by weight or more of L-methionine based on the total weight of the methionine; 1000m field 2 and applying the L-methionine in an amount equivalent to 5 to 20 kg per plant, The composition, wherein the nematode is a root-knot nematode.

2. 2. The composition of claim 1, wherein the methionine comprises 100% by weight of L-methionine based on the total weight of the methionine.

3. The composition of claim 1, wherein the methionine comprises D-methionine.

4. The composition according to claim 1, wherein the root-knot nematode is Meloidogyne incognita, Meloidogyne northernis, or Meloidogyne arenaria.

5. The composition of claim 1 in the form of a powder.

6. A method for controlling nematodes in soil, comprising applying methionine, the methionine contains 95% by weight or more of L-methionine based on the total weight of the methionine; The methionine was administered at a concentration of 1000 m 2 and applying the L-methionine in an amount equivalent to 5 to 20 kg per plant, The method, wherein the nematode is a root-knot nematode.

7. 7. The method of claim 6, wherein the methionine comprises 100% by weight L-methionine.

Images