Agricultural and horticultural materials and their manufacturing methods

Abstract

To impart antibacterial activity to plants over a long period of time using simple methods, without affecting the surrounding biological environment or aquatic animals. [Solution] The agricultural and horticultural material of the present invention consists of a composite material of spent mushroom substrate and thermoplastic resin.

Description

[Technical Field]

[0001] This invention relates to agricultural and horticultural materials and a method for manufacturing the same. [Background technology]

[0002] A conventional method for controlling crop diseases is the use of non-volatile chemically synthesized pesticides (Patent Document 1). On the other hand, the existence of volatile components from mushrooms that have a control effect against fungi and bacteria is known, and it has been proposed to use these volatile components as a means to efficiently control fungi and bacteria in a space (Patent Document 2). In addition, a method is being investigated to induce and activate the inherent resistance of plants using components extracted from spent mushroom substrate. This is because it is known that components of the cell wall of mushrooms are recognized as elicitors by plants, and the resistance of those plants is induced and activated (Patent Document 3). [Prior art documents] [Patent Documents]

[0003] [Patent Document 1] Japanese Patent Publication No. 2009-161472 [Patent Document 2] Japanese Patent Publication No. 2011-167073 [Patent Document 3] Japanese Patent Publication No. 2011-140463 [Overview of the project] [Problems that the invention aims to solve]

[0004] As described above, methods have been proposed that exert antibacterial activity against molds and bacteria, and that utilize such antibacterial activity for plant growth. However, chemically synthesized pesticides, such as those described in Patent Document 1, remain in the environment after use and can affect the surrounding biological environment and aquatic animals. Furthermore, a characteristic of many fungicides currently in use is that they have a narrow antibacterial spectrum and high selectivity, which can lead to problems such as the emergence of resistant bacteria.

[0005] Furthermore, although the volatile components disclosed in Patent Document 2 are highly safe, their volatility limits their effectiveness, as they only manifest near the molds and fungi that are being targeted for extermination.

[0006] Furthermore, the method of using spent mushroom substrate disclosed in Patent Document 3 is a method of obtaining an extract directly from spent substrate that has deteriorated and degraded over time. Therefore, each time an extract is to be obtained, steps such as sterilizing the spent substrate are necessary to obtain an extract of a certain quality. [Means for solving the problem]

[0007] The agricultural and horticultural material relating to this disclosure consists of a composite material of spent mushroom substrate and thermoplastic resin. Spent mushroom substrate, as described in Patent Document 3, is the substrate portion remaining after mushrooms have been cultivated and harvested, and was conventionally discarded. The composite material is formed when at least a portion of the surface of the spent mushroom substrate is in close contact with and mixed with a thermoplastic resin, so that the two are bonded together. The state of the composite material is such that at least a portion of the thermoplastic resin melts, and the molten portion adheres to the spent mushroom substrate before solidifying, thereby bonding the spent mushroom substrate and the thermoplastic resin.

[0008] Furthermore, the agricultural and horticultural materials related to this disclosure are materials that are placed near plants for extended periods and come into contact with water while the plants are being cultivated and growing. Plant cultivation includes hydroponics.

[0009] The mushroom spent substrate may be at least one of shiitake spent substrate, maitake spent substrate, and nameko spent substrate.

[0010] The thermoplastic resin may be a polyethylene resin, a polypropylene resin, a polyvinyl alcohol resin, or a polyester resin.

[0011] The polyester resin is preferably one of the following: polylactic acid, polybutylene adipate terephthalate, polytetramethylene adipate terephthalate, polyhydroxybutyrate, polyhydroxybutyrate polyhydroxyvalerate, polyhydroxybutyrate polyhydroxyhexanoate, polybutylene succinate, polybutylene succinate adipate, polyglycolic acid, or polycaprolactone.

[0012] Preferably, the composite material contains 10% to 70% by mass of spent mushroom substrate.

[0013] Preferably, the aforementioned agricultural and horticultural materials are containers for cultivating plants, installations placed close to plants, or contact objects attached in contact with plants.

[0014] The aforementioned container can be any container capable of storing irregularly shaped materials such as soil or liquid inside, and is not limited in terms of inner diameter, mouth shape, height, or the inner diameter and shape of the bottom. However, from the viewpoint of convenience when used as a seedling pot for agricultural products, for example, a cup shape with a roughly circular mouth is desirable, the diameter of the mouth is preferably 30 cm to 100 cm, and the thickness of the mouth is preferably 1 mm to 10 mm.

[0015] Preferably, the aforementioned horticultural materials are flower pots, seedling pots, seedling trays, ground cover films, or seedling tape.

[0016] The composite of the waste mushroom bed and the thermoplastic resin uses, as a raw material, a molded product obtained by mixing and aggregating the waste mushroom bed and the thermoplastic resin so that they adhere to each other and are not easily separated. A molded product is a solid that maintains a certain shape under the general environment in which people live, including granular, columnar, spherical, conical, plate-like, container-like, and shapes formed by joining at least one or more of these shapes, or shapes that are part of these shapes, or irregular shapes, and including pores and voids in these shapes. The size of the molded product is not particularly limited.

[0017] Typical examples of the molded product include those obtained by making the molded body of the resin blend smaller in size than the original molded body by methods such as cutting or crushing.

[0018] The method for manufacturing the agricultural and horticultural material according to the present disclosure includes a step of compositeizing the waste mushroom bed and the thermoplastic resin, a step of granulating the compositeized composite, and a step of melting and molding the granulated composite into a molded product.

Effects of the Invention

[0019] The agricultural and horticultural material of the present invention is composed of a composite of a thermoplastic resin and a waste mushroom bed. In the compositeization step, the melted thermoplastic resin covers the surface of the waste mushroom bed, preventing the waste mushroom bed from decaying and deforming over time, and allowing the cell wall components of the mushrooms contained in the waste mushroom bed to leach into the water in contact with the agricultural and horticultural material. Thereby, the growth of bacteria and fungi that cause diseases of agricultural crops can be suppressed. That is, when the corresponding bacteria are present in the water in contact with the composite, the effect of suppressing the growth of the bacteria and the effect of suppressing the germination of the fungi are manifested. Alternatively, when cultivating agricultural crops in a molded product formed into a container shape, the onset of diseases caused by bacteria in the agricultural crops is suppressed.

Brief Description of the Drawings

[0020] [Figure 1]150 μl of the diluted liquid of the recovered liquid in Example 1 was inoculated onto an agar medium and cultured at 30°C for 24 hours, and the resulting colonies were observed. [Figure 2] 150 μl of the diluted liquid of the recovered liquid in Comparative Example 1 was inoculated onto an agar medium and cultured at 30°C for 24 hours, and the resulting colonies were observed. [Figure 3] 150 μl of the diluted liquid of the recovered liquid in Example 2 was inoculated onto an agar medium and cultured at 30°C for 24 hours, and the resulting colonies were observed. [Figure 4] 150 μl of the diluted liquid of the recovered liquid in Example 8 was inoculated onto an agar medium and cultured at 30°C for 24 hours, and the resulting colonies were observed. [Figure 5] 150 μl of the diluted liquid of the recovered liquid in Comparative Example 3 was inoculated onto an agar medium and cultured at 30°C for 24 hours, and the resulting colonies were observed. [Figure 6] The growth status of tomatoes in Example 3. [Figure 7] The growth status of tomatoes in Comparative Example 4. [Figure 8] Observation of spore germination in Example 5. [Figure 9] Observation of spore germination in Example 6. [Figure 10] Observation of spore germination in the control group used for the evaluation of Example 5 and Example 6.

Mode for Carrying Out the Invention

[0021] Hereinafter, embodiments of the present disclosure will be described in detail.

[0022] The inventors of this application investigated a novel method for suppressing plant diseases using spent mushroom substrate. One known mechanism by which plants are prevented from being infected by pathogenic fungi is that β-1,3-glucan and chitin, components of the fungal cell wall, are broken down by substances induced by the plant. The oligosaccharides released by this breakdown are recognized by the plant as elicitors, and the plant expresses systemic induced resistance. The substances induced by the plant are known to be chitinase and β-1,3-glucanase substances.

[0023] As a result of various studies, we found that a resin composition can be formed by using fungal cell wall components contained in spent mushroom substrate as a raw material and further compounding it with a thermoplastic resin component, and then utilizing it as an agricultural and horticultural material. Therefore, we decided to use the elicitor contained in spent mushroom substrate. The aforementioned agricultural and horticultural material is not a chemically synthesized pesticide like those described in Patent Document 1, and is therefore safe for the environment and human health. Also, since there is no need to handle volatile components in a vaporized state, there are no spatial limitations like those disclosed in Patent Document 2. Furthermore, in the agricultural and horticultural material disclosed here, the spent mushroom substrate is compounded with a thermoplastic resin at high temperature, which sterilizes the material and results in a compound in which the spent mushroom substrate is isolated from the outside air. From the spent mushroom substrate compounded with a thermoplastic resin, a stable disease suppression effect can be obtained without sterilization treatment as in Patent Document 3. Furthermore, we confirmed that this agricultural and horticultural material has an inhibitory effect on diseases of crops such as tomatoes and cabbage, and the inventors of this application have completed the present invention.

[0024] An example of the manufacturing process for agricultural and horticultural materials in this embodiment is as follows: First, a physical mixture is created by physically mixing pelletized thermoplastic resin and spent mushroom substrate. This physical mixture is then kneaded while heating using equipment such as a single-screw kneader, twin-screw kneader, or Banbury mixer to produce a composite of spent mushroom substrate and thermoplastic resin. Using the aforementioned equipment, the composite can be produced by kneading the thermoplastic resin and spent mushroom substrate while at least a portion of the thermoplastic resin is heated and melted, causing them to adhere and bond together.

[0025] Furthermore, after stretching this composite material into a strand shape, it is cut into the aforementioned sizes using a chopper or similar tool to form pellets. These pellets can then be molded into the shape of agricultural and horticultural materials using common molding methods for thermoplastic resins, such as injection molding, blow molding, extrusion molding, vacuum molding, pressure molding, and press molding, thereby manufacturing agricultural and horticultural materials.

[0026] A pellet is defined as a material with a longest part measuring between 2 mm and 10 mm. Smaller materials than pellets may also be used. Examples of materials smaller than pellets include granules with a longest part measuring between 1 mm and 2 mm, and pulverized materials with a longest part measuring between 0.1 mm and 1 mm. For example, by growing plant seedlings in a flowerpot formed by injection molding of a composite material, it is possible to express genes related to resistance to diseases. Furthermore, the inventors of this invention have confirmed that the growth of pathogens can be suppressed by bringing a plate-shaped molded product into contact with pathogens, and have completed this invention.

[0027] (1) Raw materials (thermoplastic resin) The thermoplastic resin used as a raw material in this embodiment is not limited to a specific resin, but can be any resin that melts upon heating and can bond with spent mushroom substrate. Alternatively, a mixture of multiple thermoplastic resins may be used. Examples of thermoplastic resins include polyethylene, polyvinyl chloride, polypropylene, polystyrene, acrylonitrile-butadiene-styrene copolymer, acrylonitrile-styrene copolymer, polymethyl methacrylate, polybutylene terephthalate, polyethylene terephthalate, polylactic acid, polybutylene adipate terephthalate, polytetramethylene adipate terephthalate, polyhydroxybutyrate, polyhydroxybutyrate polysulfylvalerate, polyhydroxybutyrate polysulfylhexanoate, polybutylene succinate, polybutylene succinate adipate, polyglycolic acid, polycaprolactone, polyamide, polyoxymethylene, polyvinyl alcohol, polyphenylene ether, polycarbonate, polyphenylene sulfide, aromatic polyether ketone, and polyimide.

[0028] In particular, thermoplastic resins with a softening temperature of 150°C to 250°C are preferred due to their ease of thermal melting during manufacturing and thermal stability during use. Among these, polypropylene and polyethylene are preferred from the viewpoint of general applicability and excellent moldability. Furthermore, from the viewpoint of biodegradability and low environmental impact, polylactic acid, polybutylene adipate terephthalate, polytetramethylene adipate terephthalate, polyhydroxybutyrate, polyhydroxybutyrate polysulfate valerate, polyhydroxybutyrate polysulfate hexanoate, polybutylene succinate, polybutylene succinate adipate, polyglycolic acid, and polycaprolactone can be suitably used. Multiple types of these resins may also be used in mixture form.

[0029] (Spent mushroom substrate) Spent mushroom substrate refers to the substrate used after cultivating mushrooms by inoculating broadleaf tree logs with mushroom spawn and harvesting the mushrooms. The spent mushroom substrate used in this embodiment is not limited to any particular type, and any spent substrate from the cultivation of edible mushrooms can be used. Examples of substrates include the wood itself or a mixture of sawdust (wood powder) and rice bran. The type of mushroom is not particularly limited, and shiitake, maitake, etc., can be used, but spent shiitake mushroom substrate (logs used to cultivate shiitake mushrooms) can be suitably used from the perspective of being readily available and generally accessible.

[0030] (2) Manufacturing method (Method for manufacturing composite materials) In this embodiment, the composite can be manufactured by mixing a specified amount of thermoplastic resin and spent mushroom substrate to form a mixture, then heating and melting the thermoplastic resin, kneading it, and cooling it.

[0031] Before mixing the spent mushroom substrate with thermoplastic resin, it is dried in a drying oven at a temperature between 80°C and 100°C for approximately 48 hours until its moisture content is 60% or less (first spent mushroom substrate drying step). If the moisture content is higher than 60%, the cohesive force of the spent mushroom substrate is strong, making it difficult to pulverize in the spent mushroom substrate pulverization step described later. Temperatures lower than 80°C result in excessively long drying times and reduced productivity, while temperatures higher than 100°C are undesirable because they produce a strong odor during drying, worsening the working environment. The moisture content can be measured by methods such as the weight loss method, and it is preferable to stir the spent mushroom substrate by hand every 12 hours to ensure uniform drying.

[0032] In the spent mushroom substrate pulverization process, the dried spent mushroom substrate is pulverized using a known pulverizer and classified using a screen of 3 mm or less, removing spent mushroom substrate with a longest portion larger than 3 mm. The pulverizer is not limited to any particular type and can be a known pulverizer such as a roller mill, jet mill, hammer mill, pin mill, rotary mill, vibratory mill, planetary mill, or Wonder Crusher. If spent mushroom substrate larger than 3 mm remains, large chunks of spent mushroom substrate will be mixed into the resin during the compounding process described later, hindering uniform compounding and increasing the amount of spent mushroom substrate exposed outside the pellets when they are pelletized. If a larger amount of spent mushroom substrate with exposed portions is included in the pellets, it will be exposed to moisture, oxygen, and bacteria in the air during long-term storage, making the spent mushroom substrate more susceptible to deterioration.

[0033] After classification, the spent mushroom substrate is further dried at a temperature between 80°C and 100°C until the moisture content reaches 5% (second drying step for spent mushroom substrate). If the moisture content is greater than 5%, the error in the weight of the spent mushroom substrate used in the mixing process becomes large, making it difficult to mix the specified amount. In addition, the cohesive force between the particles of the spent mushroom substrate becomes strong, making it difficult to create a uniform compound, which is undesirable.

[0034] As described above, methods for mixing spent mushroom substrate, which has undergone drying and pulverization processes, with thermoplastic resin include weighing each into containers or bags and mixing them manually using a spatula or a rod-shaped tool that can be used for stirring, or mechanically mixing them to a nearly uniform degree using a rotary mixer such as a Henschel mixer (mixing process). From the viewpoint of ease of the above mixing process, it is preferable that both the thermoplastic resin and the spent mushroom substrate prepared are in powder form, or that the thermoplastic resin is in pellet form.

[0035] For thermal melt mixing and kneading, the mixture, which has been mixed to a nearly uniform consistency in the mixing process, can be processed using a single-screw kneader, twin-screw kneader, roll kneader, kneader, Banbury mixer, etc., and by using a combination of these, thermal melt mixing and kneading are possible (compounding process). The temperature during thermal melt mixing should be above the approximate melting point of the thermoplastic resin used; for example, for polypropylene, it can be 190°C or higher. Preferably, the upper temperature limit does not exceed 250°C. Exceeding 250°C is undesirable because the organic components contained in the spent mushroom substrate will oxidize or degrade due to heat.

[0036] By combining the materials in this way, the spent mushroom substrate becomes hot, killing off any unwanted bacteria, and a large portion of its surface is covered with thermoplastic resin, shielding it from air. As a result, the condition of the spent mushroom substrate (moisture content, sterilization status, etc.) remains constant for a long period of time.

[0037] When pelletizing the composite material after thermal melt mixing, the resin immediately after melt mixing can be pelletized or granulated before cooling, and then cooled to obtain the composite material of this embodiment.

[0038] One specific method for manufacturing pellets of the composite material is to stretch the molten mixture before cooling to form a string-like strand, which can then be cut as needed using a rotary strand cutter and cooled while being formed into granules to produce pellets or granules. The diameter of the strand can be between 0.1 mm and 10 mm. In particular, those between 1 mm and 2 mm are called granules, and those between 2 mm and 10 mm are called pellets. Pellets or granules refer to granular materials, but in this embodiment in particular, a composite material is one in which crushed spent mushroom substrate is included with at least a portion of its surface in close contact with resin, and the crushed spent mushroom substrate and resin are mixed in close contact. In other words, in this embodiment, pellets are made from the above composite material in granular form of 2 mm to 10 mm.

[0039] The granular material preferably has a longest portion of 0.1 mm or more and 10 mm or less. If it is smaller than 0.1 mm, it will contain a large amount of spent mushroom substrate with exposed portions, which will be exposed to moisture, oxygen and bacteria in the air during long-term storage of the granular material, making it more susceptible to deterioration of the spent mushroom substrate. If the longest portion exceeds 10 mm, it is undesirable because it becomes difficult to feed the composite material into the molding machine when manufacturing the agricultural and horticultural materials described later. Within the granular material, which is brown in color due to the compounding of spent mushroom substrate, the spent mushroom substrate is compounded almost uniformly, and at least a portion of the thermoplastic resin is in close contact with the spent mushroom substrate.

[0040] Furthermore, depending on the application, other additives such as pigments and flame retardants can be added as appropriate to the mixture of thermoplastic resin and spent mushroom substrate that is fed into the machine that performs heat melt mixing. The weight ratio of spent mushroom substrate in the resin mixture can be 10% by mass or more and 70% by mass or less. In particular, when molding agricultural and horticultural materials by molding the composite material as described later, it is necessary to fill the composite material even into the thin-walled part of the opening of the pot shape, and it is preferable to add plasticizers or the like to improve fluidity. The weight ratio of spent mushroom substrate in the composite material can be 10% by mass or more and 70% by mass or less. If it is less than 10% by mass, sufficient resistance-inducing activity cannot be obtained, and if it is more than 70% by mass, it becomes difficult to produce a uniform resin mixture due to aggregation of spent mushroom substrate during the manufacturing process of the resin mixture. From the viewpoint of excellent productivity and the ability to contain a higher concentration of spent mushroom substrate, 30% by mass or more and 60% by mass or less is even more preferable.

[0041] The heating temperature during manufacturing should be above the melting point of the resin used, but by setting it to approximately 100°C or higher, preferably 120°C or higher, sterilization of the spent mushroom substrate can be performed simultaneously. This also means that the spent mushroom substrate is coated with thermoplastic resin at the same time as sterilization, which suppresses subsequent contamination, oxidative degradation, and deterioration due to water absorption of the spent substrate.

[0042] (Manufacturing methods for agricultural and horticultural materials) The agricultural and horticultural materials of this embodiment can be obtained by molding the granular composite material described above. Examples of agricultural and horticultural materials include flower pots, seedling pots, seedling trays, ground covering films such as mulch films, or seed tape. In particular, the composite material described above can be suitably used as a flower pot. Alternatively, it may be used as a container for hydroponics or as a partition wall placed inside a container.

[0043] The molding method for agricultural and horticultural materials is not particularly limited, and general molding methods for thermoplastic resins can be used. Examples include injection molding, blow molding, extrusion molding, vacuum molding, pressure molding, and press molding. The simplest method for molding flower pots is to use an injection molding machine, but in order to obtain a molded body in which spent mushroom substrate and resin are homogenized, it is necessary to use a composite obtained by the above-mentioned composite manufacturing method, rather than simply putting a mixture of the two materials into the injection molding machine.

[0044] The cylinder temperature during injection molding should be above the melting point of the resin used; for example, for polypropylene, it can be 190°C or higher. Preferably, the upper temperature limit does not exceed 250°C. Exceeding 250°C is undesirable because it causes oxidation or thermal degradation of the organic components contained in the spent mushroom substrate. The fluidity of the composite of spent mushroom substrate and resin during molding is lower compared to the resin alone. To improve fluidity, a supercritical fluid may be injected into the injection molding machine cylinder and foam molding may be performed.

[0045] Furthermore, flower pots can be said to be the most versatile and easy-to-use agricultural and horticultural material for cultivating crops while suppressing diseases. For ease of handling, it is preferable to mold them to a thickness of about 0.5 mm to 5 mm, and from the viewpoint of productivity, it is preferable that they be molded by injection molding. In that case, lubricants can be added to improve fluidity. Lubricants are not limited to these, but include waxes, fatty acids, higher alcohols, fatty acid amides, fatty acid esters, or metal soaps. In particular, from the viewpoint of being biodegradable and having little impact on soil and the environment, low molecular weight paraffin wax, beeswax, rice bran wax, coconut oil, stearic acid, lauric acid, oleic acid, stearyl alcohol, lauryl alcohol, stearic acid amide, ethyl stearate, methyl oleate, calcium stearate, and magnesium stearate are preferred.

[0046] The following describes specific examples.

[0047] (Example 1) <Manufacturing of composite materials> A composite material was manufactured using polylactic acid as the thermoplastic resin and shiitake mushroom spent substrate (logs) as the spent mushroom substrate, according to the following procedure.

[0048] Polylactic acid (PLA) manufactured by Unitika Ltd., product name: TE-2000, was used. Shiitake mushroom spent substrate was crushed to a particle size of φ3 mm or less using a universal pulverizer (Sanriki Seisakusho Co., Ltd., SF-1), and dried until the moisture content was 4%. 4.5 kg and 5.5 kg of the polylactic acid and shiitake mushroom spent substrate were prepared, placed in containers, covered, and mixed by shaking. The mixed materials were then melt-mixed and kneaded using a twin-screw kneading extruder (Kurimoto Iron Works Co., Ltd., KRC Kneader). The melt-mixing and kneading conditions were: temperature setting 200°C, rotation speed 50 min- 1 The strand-like composite obtained from the discharge port was cooled in a water tank and cut into pieces approximately 5 mm long to obtain a pellet-like composite made of polylactic acid and spent shiitake mushroom substrate.

[0049] <Manufacturing of flower pots> Using the above-mentioned pelletized composite material, a cylindrical flowerpot with a closed bottom, measuring 75 mm in outer diameter, 95 mm in height, 1-5 mm in wall thickness, and a 3 mm radius at the base, was manufactured using an injection molding machine. The injection molding conditions were: resin temperature 200°C, mold temperature 30°C, injection speed 30 mm / sec, and holding pressure 40 Pa.

[0050] <Evaluation of antimicrobial activity against Escherichia coli strain NBRC3301> E. coli strain NBRC3301 was cultured in liquid medium to prepare a bacterial suspension. A flowerpot was cut into 10mm x 20mm sections, and the bacterial suspension (approximately 10mm) was placed on top of each section. 5 Three drops of 50 μl each of the bacterial suspension (cfu / ml) were added. The sections of the flowerpot to which the bacterial suspension had been added were placed in a plastic petri dish lined with a Kimwipe moistened with sterile distilled water, and incubated at 30°C for 24 hours.

[0051] After culturing, the sections of the flowerpot were placed in a bag and thoroughly washed with 2 ml of liquid culture medium, and the washing solution was collected. The absorbance of the collected washing solution at a wavelength of 600 nm was measured. In addition, 150 μl of a diluted solution of the collected washing solution was inoculated onto agar medium and cultured at 30°C for 24 hours, and the colonies were observed.

[0052] The more E. coli bacteria present in the washing solution, the more turbid the solution becomes and the higher its absorbance. Therefore, the amount of E. coli can be evaluated by the amount of absorbance.

[0053] <Evaluation Results> The absorbance at a wavelength of 600 nm was 0.164.

[0054] (Comparative Example 1) This method is the same as Example 1, except that cellulose fiber was used instead of spent mushroom substrate.

[0055] <Evaluation Results> The absorbance at a wavelength of 600 nm was 0.353. This absorbance is higher than that of Example 1, clearly indicating that there is a greater concentration of E. coli NBRC3301 strain in the washing solution than in Example 1.

[0056] Observation of the colonies revealed that, comparing Figure 1, which shows the colonies of Example 1, with Figure 2, which shows the colonies of Comparative Example 1, more colonies were formed in Comparative Example 1 than in Example 1.

[0057] (Comparative Example 2) The test was carried out in the same manner as in Example 1, except that the bacterial suspension was dropped onto a glass slide.

[0058] <Evaluation Results> The absorbance at a wavelength of 600 nm was 0.368. This absorbance is higher than in Example 1, clearly indicating that there is a greater concentration of E. coli NBRC3301 strain in the washing solution than in Example 1.

[0059] (Example 2) The test was conducted in the same manner as in Example 1, except that the tomato bacterial wilt fungus strain MAFF107633 was used for the antibacterial activity test.

[0060] <Evaluation Results> The absorbance at a wavelength of 600 nm was 0.141.

[0061] (Comparative Example 3) The experiment was conducted in the same manner as in Example 2, except that cellulose fiber was used instead of spent mushroom substrate.

[0062] <Evaluation Results> The absorbance at a wavelength of 600 nm was 0.370. This absorbance is higher than in Example 2, clearly indicating that the tomato bacterial wilt fungus MAFF107633 strain in the washing solution is more abundant than in Example 2.

[0063] Furthermore, observation of the colonies revealed that, comparing Figure 3, which shows the colonies of Example 2, with Figure 5, which shows the colonies of Comparative Example 3, more colonies were formed in Comparative Example 3 than in Example 2.

[0064] (Example 3) After manufacturing a flowerpot using the same method as in Example 1, the test was conducted in the same manner as in Example 1, except that the effect of using the flowerpot to verify the disease-suppressing effect against tomato bacterial wilt fungus was verified using the method described below.

[0065] <Verification of the effect on suppressing tomato diseases> The disease-suppressing effect on tomatoes (variety: Momotaro) was verified using the following procedure. A mixture of flower and vegetable soil and vermiculite (1:1) was placed in a flowerpot prepared as described above, and tomato seedlings were transplanted 5 days after sowing. After growing the tomatoes in the flowerpot for one week, the tomato flowerpot was placed in a plastic container and a bacterial suspension of the tomato bacterial wilt fungus MAFF107633 (10 5 Each test group was inoculated with 5 ml of cfu / ml via irrigation. The incidence of the disease was measured starting one week after inoculation.

[0066] <Verification Results> As shown in Figure 6, the incidence rate after one week was 20%.

[0067] (Comparative Example 4) The experiment was conducted in the same manner as in Example 3, except that cellulose fiber was used instead of spent shiitake mushroom substrate.

[0068] <Verification Results> As shown in Figure 7, the incidence rate after one week was 80%. This is significantly higher than in Example 3.

[0069] (Example 4) The test was conducted in the same manner as in Example 3, except that the effect of suppressing the development of cabbage sooty mold (Alternaria brassicicola, strain O-264) was verified using the method described below.

[0070] <Verification of the expression of cabbage disease resistance> Regarding cabbage (variety: Early Autumn), the verification of the disease suppression effect was carried out according to the following procedure. Flower and vegetable soil: Vermiculite (1:1) mixed soil was put into flowerpots manufactured in the same manner as in Example 3, and cabbage seedlings one week after sowing were transplanted. After growing the cabbage in the flowerpots for 4 weeks, the cabbage flowerpots were placed still in a plastic container, and a spore suspension of Alternaria brassicae O264 strain (5×10 5 cells / ml) was spray-inoculated at 1 ml per individual. The formation of leaf lesions was confirmed 24 hours after the spray inoculation. The leaf area was calculated using graph paper, and the number of lesions per 1 cm 2 was calculated using the following formula.

[0071] Number of lesions (per cm 2 ) = Number of lesions on one leaf ÷ Leaf area (cm 2 ) <Verification results> The number of lesions per 1 cm 2 was 11.3 ± 3.0.

[0072] (Comparative Example 5) It is the same as Example 4 except that cellulose fiber was used instead of the waste mushroom bed.

[0073] <Verification results> The number of lesions per 1 cm 2 was 37.7 ± 6.6. Compared with Example 4, the number of lesions was significantly larger.

[0074] (Example 5) The test was carried out in the same manner as in Example 1 except that the waste mushroom bed of mushrooms was changed to the waste mushroom bed of enoki mushrooms, and the antibacterial activity evaluation against Alternaria brassicae (O-264 strain) was carried out by the following method.

[0075] <Antibacterial activity evaluation against Alternaria brassicae (O-264 strain)> Cabbage sooty mold fungus (Alternaria brassicicola, strain O-264) was cultured in liquid medium to prepare a spore suspension. A flowerpot was cut into 10mm x 20mm sections, and the spore suspension (approximately 5 x 10) was prepared. 5 Three drops of 50 μl each were added (particles / ml).

[0076] After incubation at room temperature for 24 hours, the dropper solution was collected. Spore germination of the bacterium in the collected solution was observed under a microscope. Antimicrobial activity was evaluated by comparing the spore germination rate with that of the control group. The control group consisted of distilled water only, without any spore suspension or other additives.

[0077] <Evaluation Results> An example of the observed figures is shown in Figure 8. The spore germination rate of the cabbage black sooty mold fungus was 55.2 ± 9.5%, and a t-test compared with the control group showed a statistically significant difference at the 5% level. The spore germination inhibition rate was 37.6 ± 9.9%.

[0078] Germination inhibition rate (%) = (1 - germination rate in treated area / germination rate in control area) × 100 (Example 6) The same procedure as in Example 1 was followed, except that the spent mushroom substrate was replaced with spent maitake mushroom substrate, and the antimicrobial activity against cabbage sooty mold fungus (Alternaria brassicicola, strain O-264) was evaluated using the method described below.

[0079] <Evaluation of antimicrobial activity against cabbage black sooty mold fungus (Alternaria brassicicola, strain O-264)> Cabbage sooty mold fungus (Alternaria brassicicola, strain O-264) was cultured in liquid medium to prepare a spore suspension. A flowerpot was cut into 10mm x 20mm sections, and the spore suspension (approximately 5 x 10) was prepared. 5 Three drops of 50 μl each were added (particles / ml).

[0080] After 24 hours of incubation at room temperature, the drop solution was collected. Spore germination of the bacterium in the collected solution was observed under a microscope. Antimicrobial activity was evaluated by comparing the spore germination rate with that of the control group.

[0081] <Evaluation Results> An example of the observed figures is shown in Figure 9. The spore germination rate of the cabbage black sooty mold fungus was 66.8 ± 2.4%, and a t-test compared with the control group showed a statistically significant difference at the 5% level. In addition, the spore germination inhibition rate was 23.5 ± 4.3%.

[0082] (Example 7) The experiment was conducted in the same manner as in Example 1, except that the spent mushroom substrate was replaced with spent maitake mushroom substrate.

[0083] <Evaluation Results> The absorbance at a wavelength of 600 nm was 0.109. This absorbance value was lower than that of Example 1.

[0084] (Example 8) The experiment was conducted in the same manner as in Example 2, except that the spent mushroom substrate was replaced with spent maitake mushroom substrate.

[0085] <Evaluation Results> The absorbance at a wavelength of 600 nm was 0.111. This absorbance value was lower than that of Example 2.

[0086] Observation of the colonies revealed that, as shown in Figures 4 and 5, colony formation was suppressed compared to Comparative Example 3 (which used cellulose fiber instead of spent mushroom substrate).

[0087] From the above, it can be concluded that flower pots made by compounding spent shiitake mushroom substrate, spent maitake mushroom substrate, or spent nameko mushroom substrate with thermoplastic resin possess antibacterial activity against bacteria. Furthermore, it was found that tomatoes and cabbage grown in pots containing spent shiitake mushroom substrate exhibited resistance to diseases.

[0088] (Other embodiments) The embodiments described above are illustrative examples of the present invention, and the present invention is not limited to these examples. These examples may be combined with or partially replaced with well-known, conventional, or prior art. Modified inventions that would be easily conceived by a person skilled in the art are also included in the present invention.

[0089] Agricultural and horticultural materials are not limited to flower pots. When water comes into contact with agricultural and horticultural materials, components of the mushroom's cell wall leach out and exhibit antibacterial activity against bacteria in plants. Therefore, if agricultural and horticultural materials are placed near plants, such as seedling pots, seedling trays, ground covering films, hydroponic containers, or seed tape, the mushroom's cell wall components will be delivered to the plants via water and exert their effect.

Claims

1. A horticultural material consisting of a composite of spent mushroom substrate and thermoplastic resin.

2. The agricultural and horticultural material according to claim 1, wherein the mushroom spent substrate is at least one of shiitake spent substrate, maitake spent substrate, and nameko spent substrate.

3. The agricultural and horticultural material according to claim 1, wherein the thermoplastic resin is a polyethylene resin, a polypropylene resin, a polyvinyl alcohol resin, or a polyester resin.

4. The agricultural and horticultural material according to claim 3, wherein the polyester resin is any of polylactic acid, polybutylene adipate terephthalate, polytetramethylene adipate terephthalate, polyhydroxybutyrate, polyhydroxybutyrate polyhydroxyvalerate, polyhydroxybutyrate polyhydroxyhexanoate, polybutylene succinate, polybutylene succinate adipate, polyglycolic acid, or polycaprolactone.

5. The agricultural and horticultural material according to claim 1, wherein the composite material contains 10% by mass or more and 70% by mass or less of spent mushroom substrate.

6. The agricultural and horticultural material according to claim 1, wherein the aforementioned agricultural and horticultural material is a container for cultivating plants, an object installed in close proximity to plants, or an object attached in contact with plants.

7. The agricultural and horticultural material according to claim 1, wherein the aforementioned agricultural and horticultural material is a flower pot, a seedling pot, a seedling tray, a film for covering the ground, or seed tape.

8. A method for manufacturing agricultural and horticultural materials, comprising the steps of: compounding spent mushroom substrate with a thermoplastic resin; forming the compound into granules; and molding the granular compound into agricultural and horticultural materials.

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