JP7328698B2 - Soybean soil infectious disease control method - Google Patents

Description

The present invention relates to a method for controlling soybean from soil-borne diseases. More specifically, the present invention relates to a method for controlling soybean stem disease using glutamic acid, and compositions and kits that can be used for this method.

Soybeans are one of the important food crops that are also produced in Japan. In recent years, soybeans have become a particularly important item as a crop for converting paddy fields, and it is said that about 80% of the soybeans produced in Japan are cultivated in converted paddy fields. However, the fields converted to paddy fields have poor drainage, and soybeans grown in the fields converted to paddy fields are susceptible to damage from dampness and soil diseases when rainfall continues. In particular, soybean stalk plague, which prefers stagnant water, is on the rise in various parts of Japan, and poses a serious problem as a soil disease of soybean.

Soybean stem plague is a disease caused by bacteria of the genus Phytophthora belonging to the Oomycetes, and occurs throughout soybean growth. Soybeans affected by stem plague develop water-soaked streaks or elliptical lesions on the ground part of the stem or on the main stem and branches above it, and wither in about a week after infection, and finally utterly wither away. Since the infecting fungus of soybean stem plague can remain in the soil for a long period of time in the form of oospores, the damage caused by the plague is characteristically prolonged. In addition, stem blight-infecting bacteria remaining in the soil can serve as an additional source of infection.

At present, the techniques for controlling soybean stem plague are extremely limited. In order to control soybean stem plague, measures such as high ridge cultivation and drainage measures are sometimes taken, but they are not necessarily highly effective and cannot be easily carried out in terms of labor. As chemical pesticides for controlling soybean stem plague, chemicals containing cyazofamid agents, amisulbrom agents, etc. as ingredients have been registered. However, with regard to soybean stem disease, existing chemical pesticides are not very effective, and unnatural chemical pesticides have a high environmental impact and adversely affect plants and humans due to residual pesticides and exposure to pesticides. There are also concerns that it may affect

From this point of view, in recent years, there has been a strong demand for a technology for controlling soybean stem plague that is not only highly effective but also highly safe and has a low environmental impact. A technique for controlling soybean stem plague has been reported (Patent Document 1). The use of bacteria as biopesticides has recently attracted particular attention, and the use of bacteria of the genus Pseudomonas has been shown to be effective in controlling soil diseases caused by pathogenic bacteria of the genus Pythium and genus Fusarium. It has also been reported that the result of this is (Patent Document 2).

JP 2008-137946 A WO2019/198735

As described above, the control technology for stem blight on soybeans is limited, and there is a strong demand for a control technology for soybean stem blight that is both highly effective and safe and has a low environmental load. Accordingly, an object of the present invention is to provide a method, composition and kit capable of effectively controlling stem blight in soybean without using unnatural chemical pesticides.

Means of trying to solve the problem

As a result of intensive studies in view of the above problems, the present inventors have focused on the use of amino acids as natural compounds, and have found that glutamic acid is particularly effective in controlling soybean stem plague. In addition, the present inventors have found that such a control effect can be further enhanced by using Pseudomonas bacteria in combination with glutamic acid. Based on these findings, the present inventors have completed the present invention.

Although the present invention is preferably carried out in the manner described below, it is not limited thereto.
[Aspect 1] A method for controlling stem blight in soybeans, comprising the step of imparting glutamic acid to soybeans or soil containing soybeans.
[Aspect 2] The method according to Aspect 1, further comprising the step of applying Pseudomonas bacteria to soybeans or soil containing soybeans.
[Aspect 3] The method according to Aspect 1 or 2, wherein the soybean is in a seed or seedling state.
[Aspect 4] The method according to any one of aspects 1 to 3, wherein glutamic acid is applied before sowing or within 3 days after sowing.
[Aspect 5] The method according to any one of aspects 2 to 4, wherein the Pseudomonas bacterium is applied to the soybean before or within 3 days after sowing.
[Aspect 6] The method according to any one of Aspects 2 to 5, wherein glutamic acid and Pseudomonas bacterium are applied at the same time.
[Aspect 7] The method according to any one of Aspects 2 to 6, further comprising the step of imparting glutamic acid after imparting glutamic acid and Pseudomonas bacteria.
[Aspect 8] A composition for controlling stem plague in soybeans, containing glutamic acid.
[Aspect 9] The composition according to Aspect 8, further comprising Pseudomonas bacteria.
[Aspect 10] A kit for controlling stem plague in soybean, containing glutamic acid.
[Aspect 11] The kit according to Aspect 10, further comprising Pseudomonas bacteria.

By utilizing the present invention, it is possible to effectively control stem blight in soybeans without using unnatural chemical pesticides. Glutamic acid used in the present invention is one of natural amino acids, and is considered to have higher safety than common non-natural chemical pesticides. The Pseudomonas bacterium used in the present invention has also been used as a biopesticide, and is considered to be highly safe as is the case with glutamic acid. In addition, in the present invention, the effect of controlling soybean stem plague can be obtained with only one chemical component, or a total of two components that combine this with one type of bacterium, so the technology of the present invention can be easily used. .

FIG. 1 is a graph showing the weight of soybean plants after two weeks of cultivation. FIG. 2 is a graph showing the number of surviving soybeans during the cultivation period. The horizontal axis of the graph represents the cultivation period (days), and the vertical axis of the graph represents the number of surviving soybeans (pieces).

Although the present invention will be described in detail below, the present invention is not limited to these. Unless otherwise defined herein, scientific and technical terms used in connection with the present invention shall have the meanings that are commonly understood by those of ordinary skill in the art.

(1) Method for Controlling Stem Disease in Soybean One aspect of the present invention is a method for controlling stem disease in soybean, which comprises the step of imparting glutamic acid to soybean or soil containing soybean. In the present specification, soybean is a kind of plant belonging to the genus Soybean of the family Leguminosae of the order Legumes, and is a plant referred to by the scientific name Glycine max.

Glutamic acid is a kind of amino acid and is a compound represented by the chemical formula HOOC( _CH2 ) _2CH ( _NH2 )COOH (or _{C5H9NO4 ) .} Glutamic acid is also classified as a hydrophilic amino acid, a polar amino acid, a polar charged amino acid (polar negatively charged amino acid), or an acidic amino acid, and is sometimes abbreviated as Glu or E. Glutamic acid is known to be contained in plants and animals, specifically seaweed, wheat flour, soybeans, sugar cane, and the like.

Glutamic acid in the present invention is not particularly limited, and any of D-form (D-glutamic acid), L-form (L-glutamic acid), and DL-form (DL-glutamic acid) can be used. In the present invention, the L-form of glutamic acid (L-glutamic acid) is preferred. The CAS number of D-glutamic acid is 6893-26-1, and the CAS number of L-glutamic acid is 56-86-0.

The method of obtaining glutamic acid is not particularly limited, and it may be either natural glutamic acid isolated and purified from animals or plants, or obtained by chemical synthesis, fermentation, or the like. The glutamic acid used may be one purified by oneself or a commercially available product, and its use is not particularly limited. In the present invention, commercially available glutamic acid is preferably used.

The method of the present invention may further comprise the step of applying Pseudomonas bacteria to soybeans or soil containing soybeans. Bacteria belonging to the genus Pseudomonas belong to the phylum Proteobacteria, the class Gammaproteobacteria, Pseudomonadaceae, and are characterized by being Gram-negative aerobic bacilli. Pseudomonas bacteria have a wide range of growth and are known to live in soil, freshwater, seawater, plants, or animals.

Pseudomonas bacteria in the present invention are not particularly limited, but specific examples include Pseudomonas protegens, Pseudomonas fluorescens, Pseudomonas syringae, Pseudomonas chlo roraphis), Pseudomonas sinki Pseudomonas synxantha, Pseudomonas brassicacearum, Pseudomonas putida, Pseudomonas rhodeside, and the like. In the present invention, Pseudomonas sp. Os17 strain, and Pseudomonas sp. The St29 strain can also be used, and these bacteria have been deposited at the National Institute of Technology and Evaluation (NITE), Biotechnology Center, Patent Microorganism Depository Center (NPMD) (Kazusa, Kisarazu City, Chiba Prefecture, Japan). Kamatari 2-5-8), deposited under the accession numbers NITE P-02053 (acceptance date: May 20, 2015) and NITE P-02054 (acceptance date: May 20, 2015), respectively. there is Pseudomonas protegens, Pseudomonas sp. Os17 strain, and Pseudomonas sp. The St29 strain is used in the present invention. Among Pseudomonas protegens bacterial strains, Pseudomonas protegens CHA0 strain and Pseudomonas protegens Cab57 strain are preferably used, but are not particularly limited thereto.

The Pseudomonas bacterium may be one that has been isolated by oneself, one that has been distributed from a facility, or a Pseudomonas bacterium that is commercially available as a biopesticide product (i.e., a commercial product). may be used, and there is no particular limitation regarding its use.

In the method of the present invention, both glutamic acid and Pseudomonas bacteria are applied to soybeans or soil containing soybeans. As used herein, the term "soil" means soil in which soybeans can grow. The soil used in the present invention may be indicated by names such as culture soil, culture soil, seedling culture soil, or seedling culture soil. In addition, Yamano soil that has not undergone any treatment may be used as it is. The particle size of the soil is also not particularly limited, and any soil can be used as long as soybeans can grow. In the present invention, artificial soil for improving soil such as vermiculite may be used, but among various soils, it is particularly preferable to use nursery soil. Raising seedling soil is soil containing fertilizer that serves as a base for cultivation, and is classified as bed soil. The seedling culture medium used in the present invention may contain nitrogen, phosphoric acid and potassium, and preferably contains an organic acid. It is preferable that the seedling culture medium used in the present invention does not contain a large amount of minerals such as silicon oxide, magnesium oxide and aluminum oxide. Further, the seedling culture medium used in the present invention is preferably a seedling culture medium that has not been heat-treated at a temperature of 800° C. or higher.

In the present invention, the term "soil containing soybeans" means soil in which soybeans are present in or on the soil. When the soybean exists in the soil, the soybean may be entirely embedded in the soil, or may be partially embedded in the soil and the remaining portion may be outside the soil. may be The soil to be applied in the present invention is preferably soil in the vicinity of soybeans (for example, soil within a range of 10 cm from soybeans).

The state of the soybean to be imparted in the present invention is not particularly limited, and may be a seed or seedling, or a state in which the soybean has already grown, but is preferably in the state of seed or seedling, and more preferably in the state of seed. is. By being in the early stage of growth such as seeds and young seedlings, it is possible to suppress the beginning of stem disease, and to more effectively control stem disease in soybeans. In addition, since the soybean tissue is immature, glutamic acid and Pseudomonas bacterium easily permeate the interior of the soybean, and in this respect, stem plague can be controlled more effectively. The soybean to be imparted in the present invention may be in the state of a rooted seed or in the state of a non-rooted seed. preferable. When the soybean is already grown, glutamic acid and Pseudomonas bacteria can be applied to any part of the soybean, such as the root, leaf, main stem, or branch.

The glutamic acid and Pseudomonas bacterium described above are applied to soybeans or soil containing soybeans, but the method and means for application are not particularly limited as long as the effects of the present invention can be obtained. For example, by preparing water (aqueous solution) in which glutamic acid and Pseudomonas bacteria are suspended or dissolved together or separately, and bringing the prepared water (aqueous solution) into contact with soybeans or soil containing soybeans. It can be carried out.

The form of glutamic acid and Pseudomonas bacteria may be liquid or solid. When the form is liquid, glutamic acid and Pseudomonas bacteria can be applied to soybeans or soil containing soybeans by spraying, dripping, immersion, or the like. In the case of the immersion operation, a container may be prepared separately, and a perforated container containing soybeans or soil containing soybeans may be placed in the container containing the liquid. When the form of glutamic acid and Pseudomonas bacteria is solid, it may be applied by placing the solid on or in the soil, or by contacting the solid with the surface of soybeans. good too.

The amounts of glutamic acid and Pseudomonas bacterium to be applied to soybeans or soil containing soybeans are not particularly limited, and can be appropriately set according to the method of application. For example, when glutamic acid is applied to soybeans, it can be applied in an amount of 0.01 mM to 1 M, preferably 0.1 mM to 100 mM, per soybean individual. When Pseudomonas bacteria are applied to soybeans, they can be applied at a rate of 10 ⁴ to 10 ²⁰ CFU, preferably 10 ⁶ to 10 ¹⁰ CFU, per soybean individual. The amount of glutamic acid and Pseudomonas bacterium to be applied can be adjusted by the concentration in the preparation containing these and the amount of the preparation to be applied. When glutamic acid is a salt, the amount of glutamic acid can be calculated based on the molecular weight corresponding to its free form (glutamic acid ion).

When glutamic acid is applied to soil, for example, it can be applied in an amount of 0.01 mM to 1 M, preferably 0.1 mM to 100 mM per 1 cm ³ of soil. When Pseudomonas bacteria are applied to soil, the number of bacteria per 1 cm ³ of soil can be 10 ⁴ to 10 ²⁰ CFU, preferably 10 ⁶ to 10 ¹⁰ CFU. Similar to the above, the application amount of glutamic acid and Pseudomonas bacterium can be adjusted by the concentration in the preparation containing these and the application amount of the preparation.

Glutamic acid and Pseudomonas bacteria can be applied to soybeans or soil containing soybeans before, during, or after sowing (including seedling raising and planting periods). Although not particularly limited, it is preferably before sowing or within 3 days after sowing. As used herein, the term "seeding" means planting soybeans in soil as a starting point for growth, and includes, for example, sowing seeds in soil and planting seedlings in soil.

When glutamic acid and Pseudomonas bacteria are applied before sowing soybeans, the specific time is not particularly limited, but for example, within 7 days before sowing, within 6 days before sowing, within 5 days before sowing, and 4 days before sowing Within days, Within 3 days before sowing, Within 2 days before sowing, Within 1 day before sowing, Within 12 hours before sowing, Within 6 hours before sowing, Within 3 hours before sowing, Within 1 hour before sowing, Within 30 minutes before sowing , within 10 minutes before seeding, within 5 minutes before seeding, within 1 minute before seeding, or within 30 seconds before seeding. In addition, when soybean is applied after sowing, the time of application may be within 7 days after sowing, within 6 days after sowing, within 5 days after sowing, or within 4 days after sowing, or within 2 days after sowing. , Within 1 day after seeding, Within 12 hours after seeding, Within 6 hours after seeding, Within 3 hours after seeding, Within 1 hour after seeding, Within 30 minutes after seeding, Within 10 minutes after seeding, Within 5 minutes after seeding, Seeding It may be within 1 minute after seeding or within 30 seconds after seeding. The timing of application is typically within 7 days before or after seeding. In the present invention, it is preferable that both glutamic acid and Pseudomonas bacteria come into contact with soybeans in the early stages of soybean growth. From this point of view, the period between the time of application and the time of seeding soybeans is preferably as short as possible. For example, it is preferable to apply within at least 3 days before and after seeding, or at least within 1 day before and after seeding.

In the method of the present invention, glutamic acid and Pseudomonas bacteria may be applied simultaneously or separately. In the method of the present invention, glutamic acid and Pseudomonas bacteria are preferably applied simultaneously. Even though both components are applied at the same time, some time interval is acceptable. The time interval in that case is, for example, 10 minutes or less, 5 minutes or less, 3 minutes or less, 1 minute or less, or 30 seconds or less.

Moreover, in the method of the present invention, although not particularly limited, either one of glutamic acid and Pseudomonas bacteria can be applied and then the other can be applied within three days. The interval between both application periods may be within 2 days, within 1 day, within 12 hours, within 6 hours, within 3 hours, or within 1 hour. When glutamic acid and Pseudomonas bacterium are separately applied in this manner, the interval between the two application periods can be, for example, 30 minutes or longer, 1 hour or longer, 6 hours or longer, or 12 hours or longer. In the present invention, the Pseudomonas bacterium is considered to have a function of enhancing the action of glutamic acid against soybean stem plague, so it is preferable that the interval between the two application times is not long. From such a point of view, it is preferable that the time interval between the application of glutamic acid and the Pseudomonas bacterium is at least one day or less. In addition, the timing of application of glutamic acid and Pseudomonas bacterium to soybean seeding described above is applied as the timing of applying either one, and the other can be applied within 3 days after the application.

Either glutamic acid or Pseudomonas bacteria may be given first. That is, glutamic acid may be applied first and then Pseudomonas bacteria may be applied, or Pseudomonas bacteria may be applied first and then glutamic acid may be applied.

The method of the present invention can also include the step of further providing glutamic acid after providing glutamic acid and Pseudomonas bacteria. By further adding glutamic acid, it is considered that the effect of enhancing the effect of glutamic acid and Pseudomonas bacteria for controlling soybean stem disease can be maintained, and it is expected that soybean stem disease can be controlled more effectively. Further application of glutamic acid can be performed one or more times, and may be two or more times, three or more times, four or more times, or five or more times. The further application of glutamate is typically 1-20 times, preferably 2-10 times, more preferably 3-8 times.

Further application of glutamic acid can be carried out continuously. The interval between when to further add glutamic acid is not particularly limited. Days or less, 7 days or less, 6 days or less, 5 days or less, 4 days or less, 3 days or less, 2 days or less, 1 day or less, or 12 hours or less. The interval between additional glutamic acid feedings is typically 6 hours to 10 days, preferably 12 hours to 7 days, more preferably 1 to 3 days.

The form and means for further imparting glutamic acid are not particularly limited, and can be the same as those described above. Also, the amount of glutamic acid to be further added is not particularly limited, and can be the same as described above.

Stem blight in soybeans is usually caused by fungi of the genus Phytophthora. Phytophthora is a fungus belonging to the Oomycete class among fungi, and is known to be a soil fungus that grows in plant tissues after infection. A representative example of a Phytophthora spp. that causes stem blight in soybeans is Phytophthora sojae (more specifically Phytophthora sojae N1).

(2) Composition for controlling stem plague in soybean One aspect of the present invention is a composition for controlling stem plague in soybean, containing glutamic acid. The composition of the present invention may further comprise a Pseudomonas bacterium.

The glutamic acid and Pseudomonas bacterium used in the composition of the present invention are as described above.

The amount of glutamic acid contained in the composition of the present invention can be appropriately set according to the type of dosage form. The content of glutamic acid in the composition of the present invention is, for example, 0.01 mM to 1 M, preferably 0.1 mM to 100 mM per 100 g of the composition, but is not particularly limited.

The amount of Pseudomonas bacterium contained in the composition of the present invention can be appropriately set according to the species of the bacterium, the properties of the bacterium (such as resistance to drying), the type of dosage form, and the like. The content of Pseudomonas bacteria in the composition of the present invention is, for example, 10 ⁴ to 10 ²⁰ CFU, preferably 10 ⁶ to 10 ¹² CFU, per 100 g of the composition, but is not particularly limited.

The method of adding the Pseudomonas bacterium to the composition of the present invention is not particularly limited, and the composition may be added as it is. For example, Pseudomonas bacterium is cultured by a method known to those skilled in the art, and if it is a liquid medium, it is collected by centrifugation or the like, and if it is a solid medium, the formed colonies are collected with a platinum loop or the like, and the composition of the present invention is added. can be added. Alternatively, the bacteria of the genus Pseudomonas may be added to the composition of the present invention as a solid substance after being freeze-dried by a method known per se from the state of being stored in a liquid.

The composition of the present invention may contain additives such as excipients, thickeners, binders, stabilizers, preservatives, pH adjusters, coloring agents and flavoring agents. Various additives are not particularly limited, but materials known in the technical field of biopesticides can be used, and the amount to be added can be appropriately adjusted based on the known techniques of those skilled in the art. Moreover, the form of the composition of the present invention may be any form such as liquid, solid, gel, paste, etc., and can be appropriately set according to usage conditions and the like.

Compositions of the invention may be in the form of concentrates. The concentration ratio in that case is not particularly limited, and can be, for example, 2 to 1000 times, 5 to 100 times, or 10 to 50 times. When the composition of the present invention is a concentrate, it can be appropriately diluted with a solvent such as water, and the diluted product can be applied to soybeans or soil containing soybeans. The contents of glutamic acid and Pseudomonas bacteria in the composition of the present invention can be set according to the concentration ratio.

When Pseudomonas bacteria are used, the composition of the present invention may consist of a single formulation containing glutamic acid and Pseudomonas bacteria, or two formulations containing glutamic acid and Pseudomonas bacteria separately. may be configured as When the composition of the present invention is configured as two formulations, the two formulations are preferably used in combination (that is, a combination drug). Moreover, when the composition of the present invention is configured as two formulations, the two formulations may be in different types of dosage forms, or may be in the same type of dosage form.

The composition of the present invention is used for controlling stem blight in soybeans. When Pseudomonas bacteria are used, the compositions of the present invention can also be used as biopesticides or microbial pesticides. Therefore, when Pseudomonas bacteria are used, the composition of the present invention can also be called an agricultural chemical composition.

(3) Kit for Controlling Stem Disease in Soybean One aspect of the present invention is a kit for control of stem disease in soybean, which contains glutamic acid. The kit of the present invention can further contain a Pseudomonas bacterium.

The glutamic acid and Pseudomonas bacterium used in the kit of the present invention are as described above.

Glutamic acid and Pseudomonas bacteria may be in the form of reagents or preparations, and are not particularly limited. Moreover, when Pseudomonas bacteria are used, both glutamic acid and Pseudomonas bacteria may be contained in the same preparation, or may be contained separately in separate preparations. When glutamic acid and Pseudomonas bacteria are separated into separate formulations, the formulations may be in different types of dosage forms or in the same type of dosage form.

The form of the formulation used in the kit of the present invention is not particularly limited, and may be in any form such as liquid, solid, gel, paste, and the like. In addition, the content of glutamic acid and Pseudomonas bacteria in the formulation is not particularly limited, and can be arbitrarily set according to the composition of the present invention described above.

The formulation used in the kit of the present invention may be individually packaged for single use, or may be used multiple times (e.g., twice, three times, four times, five times, ten times, or more). The container to be used is also not particularly limited, and can be appropriately set according to the amount of the formulation used.

When glutamic acid and Pseudomonas bacterium are separated into separate reagents or formulations in the kit of the present invention, both need not be incorporated in the same package, and are packaged separately and used together. may be In addition, the kit of the present invention may contain instructions for use of glutamic acid and Pseudomonas bacteria.

The kit of the present invention is used for controlling stem blight in soybeans. When Pseudomonas bacteria are used, the kit of the present invention can also be used as a biopesticide or microbial pesticide.

EXAMPLES The present invention will be specifically described below with reference to Examples, but these are not intended to limit the technical scope of the present invention. A person skilled in the art can easily modify and change the present invention based on the description of this specification, and these are also included in the technical scope of the present invention.

<Material>
Test plant: soybean seeds (variety: Enrei)
Soybean stem blight fungus (Phytophthora spp.): Phytophthora sojae N1
Pseudomonas bacteria: Pseudomonas protegens Cab57
Soil: Seedling soil (Plantation Iwamoto)

V8 medium:
(Medium composition)
V8 vegetable juice Original (Campbell) 40mL
_CaCO3 0.6g
315 mL to 35 mL supernatant of mixture of _H2O V8 vegetable juice and _CaCO3
Agar, Powder (Wako) 4.36g
(Preparation method)
1) 40 mL of V8 vegetable juice Original and 0.6 g of CaCO ₃ were put into a 100 mL beaker and stirred with a stirrer for 5 to 10 minutes.
2) The solution obtained in 1) was transferred to a 50 mL falcon tube and centrifuged (3,000 rpm, 3 minutes).
3) 35 mL of the supernatant was collected in a 500 mL beaker, and 315 mL of pure water was added.
4) 1.09 g of Agar and Powder were each weighed into four 200 mL Erlenmeyer flasks, 87.5 mL each of the preparation liquid obtained in 3) was added, the neck of the flask was covered with aluminum foil and autoclaved (121 ° C., 20 minutes).
5) Dispensed into petri dishes.

Nutrient Agar (NA) medium:
Blood agar base (Oxoid) 40g
Yeast extract (Oxoid) 5g
1000 mL _H2O
(After the medium was prepared, it was autoclaved and dispensed into petri dishes.)
Nutrient yeast broth (NYB) medium:
Nutrient broth (Oxoid) 25g
Yeast extract (Oxoid) 5g
1000 mL _H2O
(After preparing the medium, autoclave was performed.)

<Method>
Before conducting the test, the seedling culture medium to be used was sterilized by autoclaving, and the Phytophthora spp. was cultured using V8 medium. For Pseudomonas bacteria, a single colony obtained in NA medium is liquid-cultured in NYB medium, the culture solution is centrifuged, and the precipitate is diluted with sterilized water to obtain a bacterial suspension of OD600 = 0.1. A liquid was prepared. Also, the soybean seeds to be tested were placed in a moisturizing box and stored in the dark at 4° C. for 24 hours.

V8 medium in which Phytophthora was cultured was passed through a 10 mL syringe (with an injection needle (18G)) and finely crushed, and the culture medium was added to the seedling culture medium and mixed thoroughly. The amount of the Phytophthora spp. culture V8 medium added was 4.63 g per 1 L of seedling culture medium. After adding the V8 medium, 180 mL of the seedling culture medium was evenly put into seedling-raising trays (6 cm square per section, 5.5 cm deep) with holes in the bottom and permeable to water. Then, 5 soybean seeds were sown on the nursery medium with the hypocotyl portion facing down.

Four types of test plots were set: (a) application of water only, (b) application of Pseudomonas bacteria only, (c) application of glutamic acid only, and (d) application of glutamic acid and Pseudomonas bacteria. The specific procedure is as follows.

Water or a 10 mM glutamic acid aqueous solution was placed in a vat, and a seedling tray seeded with soybean seeds was immersed therein. The amount of water or 10 mM glutamic acid aqueous solution was 50 mL per section of the seedling-raising tray. Almost simultaneously with soaking the seedling trays, sterile water or a bacterial suspension of Pseudomonas was added onto the soybean seeds. The amount of sterilized water and bacterial suspension added was 5 mL per section of the seedling tray. The application of glutamic acid and Pseudomonas bacteria to soybeans or soil containing soybeans was performed within 1 hour after seeding the soybeans, and the interval between application of glutamic acid and Pseudomonas bacteria was within 5 minutes.

After that, the seedling-raising tray was covered with a wrap film and allowed to stand in a plant incubator. Soybeans were cultivated at 25° C. for 2 weeks with a 16-hour light period and an 8-hour dark period. Water or 10 mM glutamic acid aqueous solution in the vat was replenished every 5 days during the cultivation period. The amount of water or 10 mM glutamic acid aqueous solution to be replenished was 50 mL per section of the seedling-raising tray in the same manner as described above. If water or 10 mM glutamic acid aqueous solution remained in the vat at the time of replenishment, it was discarded and fresh water or 10 mM glutamic acid aqueous solution was replenished.

After cultivating for 2 weeks, the seedling culture soil adhering to the roots was thoroughly washed away, the two leaves were removed from the soybean plants, the weight was measured, and the average value was calculated. In addition, the number of surviving soybeans was recorded over time during the cultivation period.

The weight of the soybean plant body after cultivation is as shown in FIG. 1, and it was found that the addition of glutamic acid has the effect of controlling soybean stem plague, and the combined use of Pseudomonas bacteria has the same effect. was found to increase.

The number of surviving soybeans during the cultivation period is as shown in FIG. Thirteen days after the start of cultivation, the number of surviving soybeans was 7 in the test plot to which only water was given and the test plot to which only Pseudomonas bacteria were given, whereas in the test plot to which only glutamic acid was given, the soybean survived. There were 9 soybeans, and 10 surviving soybeans were found in the test group to which glutamic acid and Pseudomonas bacteria were applied. These results also indicated that the effect of controlling soybean stem plague was obtained by the addition of glutamic acid, and that the effect was enhanced by the combined use of Pseudomonas bacteria.

The technology provided by the present invention is useful in the agricultural field related to soybean production. In addition, the Pseudomonas bacteria and glutamic acid provided by the present invention can be used in the field of agrochemicals, particularly in the field of biopesticides.

Claims (11)

A method for controlling stem blight in soybeans, comprising the step of imparting glutamic acid to soybeans or soil containing soybeans. 2. The method according to claim 1, further comprising the step of applying Pseudomonas bacteria to soybeans or soil containing soybeans. 3. The method according to claim 1 or 2, wherein the soybean is in the form of seed or seedling. The method according to any one of claims 1 to 3, wherein glutamic acid is applied before sowing or within 3 days after sowing. The method according to any one of claims 2 to 4, wherein the Pseudomonas bacterium is applied before or within 3 days after seeding soybean. The method according to any one of claims 2 to 5, wherein glutamic acid and Pseudomonas bacterium are applied at the same time. The method according to any one of claims 2 to 6, further comprising a step of applying glutamic acid after applying glutamic acid and Pseudomonas bacteria. A composition for controlling stem blight on soybeans, comprising glutamic acid. 9. The composition of claim 8, further comprising Pseudomonas bacteria. A kit for controlling stem blight in soybeans, containing glutamic acid. 11. The kit of claim 10, further comprising Pseudomonas bacteria.