Gastropod control film and method for cultivating plants

Abstract

The gastropod control film of the present invention has at least an inorganic filler layer, and the inorganic filler layer contains an inorganic filler and a thermoplastic resin. The inorganic filler layer is the outermost layer. The inorganic filler contains calcium carbonate particles. The content ratio of the inorganic filler in the gastropod control film exceeds 50.0% by mass. The density of the gastropod control film is 1.05 g / cm 3 or more and 1.25 g / cm 3 or less. The cultivation method of plants of the present invention uses the above-mentioned gastropod control film.

Description

Technical Field

[0001] The present invention relates to a method for culturing a gastropod control film and a plant. Background Art

[0002] In the cultivation of plants such as crops, from the viewpoint of improving the yield and quality of crops, it is necessary to focus on suppressing the invasion of pests into crops. Representative pests include gastropods (e.g., slugs and snails).

[0003] As a method for dealing with gastropods, for example, an attractant and repellent containing an insecticide (e.g., paraformaldehyde and iron phosphate) can be put in farmland. Further, as another method for dealing with gastropods, for example, a gastropod control film containing a copper compound can be placed in farmland (e.g., Patent Document 1).

[0004] 〔Patent Document〕

[0005] Patent Document 1: Japanese Patent Application Laid-Open No. 2018-035070 Summary of the Invention

[0006] However, even when using the above-mentioned attractant and repellent and gastropod control film, it is difficult to sufficiently suppress the invasion of gastropods. Further, in the above-mentioned attractant and repellent and gastropod control film, the insecticide and the copper compound may penetrate into the farmland.

[0007] The present invention has been made in view of the above problems, and an object thereof is to provide a gastropod control film capable of suppressing the invasion of gastropods and a method for culturing a plant using the gastropod control film.

[0008] The gastropod control film of the present invention has at least an inorganic filler layer containing an inorganic filler and a thermoplastic resin. The inorganic filler layer is the outermost layer. The inorganic filler contains calcium carbonate particles. In the gastropod control film, the content ratio of the inorganic filler exceeds 50.0% by mass. The density of the gastropod control film is 1.05 g / cm 3 above 1.25 g / cm 3 below.

[0009] The method for culturing a plant of the present invention uses the above-mentioned gastropod control film.

[0010] 〔Effect of the Invention〕

[0011] The gastropod control film and the method for culturing a plant of the present invention can suppress the invasion of gastropods. Brief Description of the Drawings

[0012] Figure 1It is a cross-sectional view of an exemplary structure of the gastropod control film of the present invention.

[0013] Figure 2 It is a cross-sectional view of another exemplary structure of the gastropod control film of the present invention.

[0014] Figure 3 It is a cross-sectional view of yet another exemplary structure of the gastropod control film of the present invention.

[0015] Figure 4 It is a cross-sectional view of an example of the cultivation method of the plant of the present invention.

[0016] Figure 5 It is a top view of another example of the cultivation method of the plant of the present invention. Detailed Embodiments

[0017] Hereinafter, embodiments of the present invention will be described. However, the present invention is not limited to the embodiments and can be implemented with appropriate modifications within the scope of the object of the present invention. Unless otherwise specified, each material described in the embodiments of the present invention can be used alone or in combination of two or more.

[0018] <First Embodiment: Gastropod Control Film>

[0019] The gastropod control film (hereinafter sometimes simply referred to as the insect repellent film) according to the first embodiment of the present invention includes at least an inorganic filler layer, and the inorganic filler layer contains an inorganic filler and a thermoplastic resin. The inorganic filler layer is the outermost layer. The inorganic filler contains calcium carbonate particles. In the insect repellent film of the present invention, the content ratio of the inorganic filler exceeds 50.0% by mass. The density of the insect repellent film of the present invention is 1.05 g / cm 3 above 1.25 g / cm 3 below. The insect repellent film of the present invention can inhibit the invasion of gastropods.

[0020] In addition, the density of the insect repellent film of the present invention means the ratio of the mass of the insect repellent film of the present invention to the volume calculated based on the size of the insect repellent film of the present invention (i.e., the bulk density).

[0021] The insect repellent film of the present invention can be used, for example, as a ground cover film, a rope for supporting plants (e.g., a towing rope and a tying rope), and a fruit bag for wrapping fruits. Further, the insect repellent film of the present invention can also be processed into a strip shape and used as a tape for preventing gastropods from invading farmland.

[0022] The present inventors have found that a film containing calcium carbonate particles and a thermoplastic resin has a good insect repellent effect against gastropods. Further, the present inventors have found that in the above-mentioned film, by reducing the density and reducing the content ratio of the thermoplastic resin (increasing the content ratio of the inorganic filler), the insect repellent effect against gastropods can be improved. Based on the above knowledge, the present inventors have completed the present invention. Regarding the reason why the insect repellent film of the present invention has the above effects, although it is not very clear, it can be speculated as at least one of the following first to third reasons.

[0023] The first reason will be described. In the insect repellent film of the present invention, it can be judged that a part of the calcium carbonate particles exist in a state of protruding needle-like from the surface of the insect repellent film of the present invention, and a minute needle-like sword mountain structure is formed on the surface of the insect repellent film of the present invention. This minute needle-like sword mountain structure may injure gastropods. Therefore, it can be judged that the movement of gastropods on the insect repellent film of the present invention can be blocked.

[0024] The second reason will be described. Gastropods generally have the characteristic of preferring an acidic environment and not liking an alkaline environment. In the insect repellent film of the present invention, it can be judged that calcium carbonate as an alkaline compound gradually dissolves out with use, so that the surface becomes alkaline. Therefore, it can be judged that the movement of gastropods on the insect repellent film of the present invention can be blocked.

[0025] The third reason will be described. Gastropods generally have the characteristic of preferring a humid environment. The calcium carbonate particles contained in the insect repellent film of the present invention have a certain hygroscopicity. Thus, the surface of the insect repellent film of the present invention is drier than the surrounding environment. Therefore, it can be judged that the movement of gastropods on the insect repellent film of the present invention can be blocked.

[0026] Further, compared with the theoretical density calculated based on the densities of the above-mentioned calcium carbonate particles (about 2.7 g / cm 3 ) and the thermoplastic resin (about 0.9 g / cm 3 ), the density of the insect repellent film of the present invention is much smaller. The reason is that in the inorganic filler layer of the insect repellent film of the present invention, there are relatively large voids (for example, a porosity of 15 to 20% by volume) between the calcium carbonate particles and the thermoplastic resin. Therefore, it can be judged that in the insect repellent film of the present invention, due to the presence of voids in the inorganic filler and the low content ratio of the thermoplastic resin, the calcium carbonate particles contained in the inorganic filler layer are likely to gradually ooze out and be exposed (seep to) the surface. In this way, it can be judged that the insect repellent film of the present invention can effectively exert the insect repellent effects caused by the above-mentioned first to third reasons through the gradual oozing out and exposure of the calcium carbonate particles on the surface.

[0027] In addition, in the insect-repellent film of the present invention, calcium carbonate particles as an active ingredient are fixed on the film by a thermoplastic resin. Therefore, even in a humid situation caused by sprinkling water or rainfall, the insect-repellent effect generated by the above-mentioned first to third reasons can be maintained. Therefore, by using the insect-repellent film of the present invention, compared with the case of directly placing calcium carbonate particles or an attractant insecticide on farmland, the insect-repellent effect can be exerted for a long time.

[0028] In addition, the insect-repellent film of the present invention can also exert the following first to third effects in addition to suppressing the invasion of gastropods.

[0029] The first effect will be described. The content ratio of the inorganic filler in the insect-repellent film of the present invention exceeds 50.0% by mass. Thus, in the insect-repellent film of the present invention, the content ratio of the inorganic filler is the highest and it can be disposed of as combustible waste. Therefore, the disposal cost of the insect-repellent film of the present invention is low. Also, as the insect-repellent film of the present invention is used, sometimes a part of a plant (for example, leaves, roots, stems, and vines) will adhere to it. These parts of the plant need to be disposed of as combustible waste. Since the insect-repellent film of the present invention can be disposed of as combustible waste as described above, even if a part of a plant adheres to it during use, it can be directly disposed of as combustible waste without separating the part of the plant. Therefore, the insect-repellent film of the present invention is easy to handle as garbage. In contrast, cultivation materials made of resin (for example, ground covering films made of resin and ropes made of resin) need to be disposed of as non-combustible waste. Therefore, after a part of a plant adheres to a cultivation material made of resin, it is necessary to separate the part of the plant from the cultivation material made of resin before processing, which is time-consuming and laborious in garbage disposal.

[0030] The second effect will be described. The insect-repellent film of the present invention contains calcium carbonate particles, which are high-whiteness particles, so the surface whiteness is high. In the cultivation of crops and other plants, flying insects (for example, butterflies, moths, and aphids) as pests tend to dislike substances with high whiteness. Therefore, when the insect-repellent film of the present invention is placed near crops, the invasion of flying insects can also be suppressed. Also, when the insect-repellent film of the present invention is placed near plants, the sunlight reflected by the insect-repellent film of the present invention irradiates the crops, promoting the photosynthesis of the crops. As a result, the insect-repellent film of the present invention can improve the yield and quality of the crop harvest. For example, in the cultivation of tomatoes, by using the insect-repellent film of the present invention as a ground covering film, the sugar content of the harvested tomatoes can be increased.

[0031] The third effect will be described. As the insect-repellent film of the present invention is used, calcium carbonate particles will dissolve out, making the surrounding soil and the surface of the insect-repellent film of the present invention alkaline. Generally, in an alkaline environment, the growth of molds and fungi is inhibited. Therefore, the insect-repellent film of the present invention can exert an anti-mold effect and an anti-fungal effect.

[0032] The content ratio of the inorganic filler in the insect repellent film of the present invention exceeds 50.0% by mass, preferably exceeds 50.0% by mass and is 65.0% by mass or less, and more preferably exceeds 50.0% by mass and is 60.0% by mass or less. By making the content ratio of the inorganic filler in the insect repellent film of the present invention exceed 50.0% by mass, the predation of gastropods can be effectively inhibited. Also, the carbon dioxide emissions when incinerating the insect repellent film of the present invention can be reduced. Also, generally speaking, inorganic fillers are cheaper than thermoplastic resins, so by using more inorganic fillers, the material cost of the insect repellent film of the present invention can be reduced. By making the content ratio of the inorganic filler in the insect repellent film of the present invention 65.0% by mass or less, the strength of the insect repellent film of the present invention can be improved.

[0033] The density of the insect repellent film of the present invention is 1.05 g / cm 3 to 1.25 g / cm 3 or less, preferably 1.10 g / cm 3 to 1.20 g / cm 3 or less. By making the density of the insect repellent film of the present invention 1.05 g / cm 3 to 1.25 g / cm 3 or less, the insect repellent effect of the insect repellent film of the present invention can be more effectively exerted.

[0034] The insect repellent film of the present invention can be of a single-layer structure or a multi-layer structure. When the insect repellent film of the present invention is of a multi-layer structure, the number of layers of the inorganic filler layer in the insect repellent film of the present invention can be 1 layer or 2 layers or more. When the insect repellent film of the present invention has 2 layers or more of inorganic filler layers, at least 1 layer of the inorganic filler layer is the outermost layer. In such a case, the other inorganic filler layers can be the outermost layer or the inner layer. When the insect repellent film of the present invention is of a multi-layer structure, the insect repellent film of the present invention preferably further has a resin layer containing a thermoplastic resin.

[0035] The insect repellent film of the present invention is used, for example, by being placed in places such as soil. When the insect repellent film of the present invention is of a multi-layer structure, the insect repellent film of the present invention is preferably used with the surface on the side of the inorganic filler layer as the upper side (opposite side of the soil).

[0036] Hereinafter, with reference to the drawings, the insect repellent film of the present invention will be described in detail. Figure 1 It is a cross-sectional view of an insect repellent film 10 which is an example of the insect repellent film of the present invention. The insect repellent film 10 has a single-layer structure. Specifically, the insect repellent film 10 includes an inorganic filler layer 11.

[0037] Figure 2FIG. 0 is a cross-sectional view of the insect repellent film 20, which is another example of the insect repellent film of the present invention. The insect repellent film 20 has a two-layer structure. Specifically, the insect repellent film 20 includes an inorganic filler layer 21 and a resin layer 22. The inorganic filler layer 21 and the resin layer 22 are each the outermost layer.

[0038] When the insect repellent film 20 is a ground covering film, the resin layer 22 preferably further contains a black pigment (e.g., carbon black and graphite). As described above, the surface whiteness of the inorganic filler layer 21 is high. Therefore, when the resin layer 22 further contains a black pigment, the insect repellent film 20 has a structure in which the surface on the side of the inorganic filler layer 21 is white and the surface on the side of the resin layer 22 is black. In this way, the insect repellent film 20 with one side white and the other side black can reduce the ground temperature by covering the ground with the white side up and can increase the ground temperature by covering the ground with the black side up, so it is suitable as a ground covering film.

[0039] Figure 3 FIG. 7 is a cross-sectional view of the insect repellent film 30, which is another example of the insect repellent film of the present invention. The insect repellent film 30 has a three-layer structure. Specifically, the insect repellent film 30 includes a pair of inorganic filler layers 31 and a resin layer 32. Each of the pair of inorganic filler layers 31 is the outermost layer. The resin layer 32 is the inner layer.

[0040] As described above, the insect repellent film of the present invention has been described in detail with reference to the accompanying drawings. However, the structure of the insect repellent film of the present invention is not limited to Figures 1 to 3 the structure shown. For example, on the basis of including an inorganic filler layer, the insect repellent film of the present invention may further include other layers other than the inorganic filler layer and the resin layer.

[0041] The overall thickness of the insect repellent film of the present invention is preferably 15 μm or more and 200 μm or less, more preferably 25 μm or more and 50 μm or less. By making the overall thickness of the insect repellent film of the present invention 15 μm or more, the strength of the insect repellent film of the present invention can be improved. By making the overall thickness of the insect repellent film of the present invention 200 μm or less, the insect repellent film of the present invention can be made lighter.

[0042] [Inorganic filler layer]

[0043] The inorganic filler layer contains an inorganic filler and a thermoplastic resin. In the inorganic filler layer, the inorganic filler is dispersed in a matrix composed of the thermoplastic resin.

[0044] When the insect repellent film of the present invention is a multi-layer structure, in the insect repellent film of the present invention, the total thickness T N of the inorganic filler layer relative to the overall thickness T A of the insect repellent film (100 × T N / T A ) is preferably 70% or more and 90% or less.

[0045] (Inorganic filler)

[0046] The inorganic filler contains calcium carbonate particles. Depending on the procurement source, the purity of the calcium carbonate particles used as the inorganic filler varies greatly. Specifically, most of the calcium carbonate particles used as the inorganic filler are obtained by directly granulating calcium carbonate ore obtained as a mineral resource without refining. Therefore, the purity of the calcium carbonate particles varies greatly depending on the origin. For example, in some origins, there are low-purity calcium carbonate particles with a calcium carbonate content of about 70% by mass. On the other hand, there are also high-purity calcium carbonate particles obtained by chemical synthesis for use in food and medicine.

[0047] The insect-repellent film of the present invention preferably contains calcium carbonate particles with as high a purity as possible. Specifically, the content ratio of calcium carbonate in the calcium carbonate particles is preferably 90% by mass or more, more preferably 95% by mass or more, and further preferably 97% by mass or more. By making the content ratio of calcium carbonate in the calcium carbonate particles 90% by mass or more, even when using high-purity calcium carbonate particles, the following effects can be exerted. The higher the purity of the calcium carbonate particles, the higher the diffuse reflectance. Therefore, when the purity of the calcium carbonate particles is higher, the whiteness becomes higher, and the effects of repelling flying insects and promoting the photosynthesis of crops can be improved. Also, when the purity of the calcium carbonate particles is higher, the pH becomes more stable, so that the antifungal and antimildew properties can be stably exerted. Also, when the purity of the calcium carbonate particles is higher, the impact on humans and the environment can be more effectively inhibited.

[0048] The maximum particle size of the calcium carbonate particles is preferably 20 μm or less. By making the maximum particle size of the calcium carbonate particles 20 μm or less, it is easy to form the above-mentioned minute needle-shaped kenzan structure on the surface of the insect-repellent film of the present invention. As a result, the insect-repellent film of the present invention can further effectively inhibit the invasion of gastropods.

[0049] In addition, the maximum particle size of the calcium carbonate particles can be measured by the following method. First, using an electron microscope, randomly select 5 positions (field of view: 100 μm × 100 μm) from the cross-section of the inorganic filler layer, and measure the particle size (major axis) of the calcium carbonate particles. Then, the maximum value of the particle size of the calcium carbonate particles measured is taken as the maximum particle size of the calcium carbonate particles.

[0050] The calcium carbonate particles can also be surface-treated. Examples of the surface treatment include silane coupling agent treatment and metal soap treatment (for example, calcium stearate treatment). By surface-treating the calcium carbonate particles, the generation of excessive voids at the interface between the calcium carbonate particles and the thermoplastic resin can be inhibited. As a result, the strength of the insect-repellent film of the present invention can be improved.

[0051] In the case where the insect repellent film of the present invention is a multi-layer structure, the content ratio of the inorganic filler in the inorganic filler layer is preferably more than 50.0% by mass and 65.0% by mass or less, more preferably more than 50.0% by mass and 60.0% by mass or less. By making the content ratio of the inorganic particles in the inorganic filler layer exceed 50.0% by mass, the insect repellent film of the present invention can further effectively inhibit the invasion of gastropods. By making the content ratio of the calcium carbonate particles in the inorganic filler layer 65.0% by mass or less, the strength of the insect repellent film of the present invention can be improved.

[0052] The inorganic filler layer may also contain other inorganic fillers other than calcium carbonate particles. Examples of other inorganic fillers include: calcium sulfate particles, barium sulfate particles, kaolin particles, mica particles, zinc oxide particles, dolomite particles, glass fibers, hollow glass microspheres, silica particles, chalk particles, talc powder, pigment particles, titanium dioxide particles, silica particles, bentonite, clay, diatomaceous earth, and zeolite particles.

[0053] The content ratio of the calcium carbonate particles in the inorganic filler is preferably 90% by mass or more, more preferably 95% by mass or more.

[0054] (Thermoplastic resin)

[0055] Examples of the thermoplastic resin contained in the inorganic filler layer include: polyolefin resins, ABS resins, polyamide resins, polystyrene resins, and polyester resins (for example, polyethylene terephthalate resins and polybutylene terephthalate resins).

[0056] Examples of polyolefin resins include polyethylene resins and polypropylene resins. Examples of polyethylene resins include high-density polyethylene (HDPE), low-density polyethylene (LDPE), medium-density polyethylene, and linear low-density polyethylene (L-LDPE).

[0057] The thermoplastic resin contained in the inorganic filler layer is preferably a polyolefin resin, more preferably a polyethylene resin.

[0058] (Other additives)

[0059] The inorganic filler layer may further contain other additives other than inorganic fillers. Examples of other additives include: coupling agents, lubricants, filler dispersants, antistatic agents, antioxidants, heat stabilizers, ultraviolet absorbers, and weather stabilizers.

[0060] As described above, in the inorganic filler layer, the content ratio of the inorganic filler is high. Therefore, the inorganic filler layer preferably contains a filler dispersant as another additive. By including a filler dispersant in the inorganic filler layer, the dispersibility of the inorganic filler can be improved. Examples of the filler dispersant include metal soaps (e.g., calcium stearate and magnesium stearate). When the inorganic filler layer contains other additives, the content ratio of the other additives in the inorganic filler layer is preferably 0.5% by mass or more and 5.0% by mass or less.

[0061] [Resin layer]

[0062] The resin layer is a layer containing a thermoplastic resin. The thickness ratio of the resin layer is 2.0% or more and 20.0% or less, preferably 4.0% or more and 10.0% or less, relative to the total thickness of the insect repellent film of the present invention. By making the thickness ratio of the resin layer 2.0% or more, the processability of the insect repellent film of the present invention can be improved. By making the thickness ratio of the resin layer 20.0% or less, it is easy to adjust the content ratio of the inorganic filler in the insect repellent film of the present invention to more than 50.0% by mass.

[0063] Examples of the thermoplastic resin contained in the resin layer may include the resins exemplified as the thermoplastic resins contained in the inorganic filler layer. The thermoplastic resin contained in the resin layer is preferably a polyolefin resin, more preferably a polyethylene resin.

[0064] The content ratio of the thermoplastic resin in the resin layer is preferably 90% by mass or more, more preferably 95% by mass or more.

[0065] The resin layer preferably does not contain an inorganic filler, but may contain a small amount of an inorganic filler. The content ratio of the inorganic filler in the resin layer is preferably 0% by mass or more and 10% by mass or less, more preferably 0% by mass or more and 5% by mass or less.

[0066] [Manufacturing method]

[0067] The insect repellent film of the present invention can be manufactured, for example, by the inflation method. Specifically, when the insect repellent film of the present invention is single-layered, a material for forming an inorganic filler layer containing an inorganic filler and a thermoplastic resin is prepared as the material for forming the inorganic filler layer. Then, the material for forming the inorganic filler layer is extruded through an extruder equipped with an annular die. Air is blown into the interior of the obtained cylindrical extrudate to cool it, and then, by cutting, a single-layered insect repellent film of the present invention can be obtained.

[0068] Further, in the case where the insect-repellent film of the present invention is multilayered, the above-described material for forming the inorganic filler layer is prepared, and a material for forming a resin layer containing a thermoplastic resin is also prepared as the material for forming the resin layer. Then, the material for forming the inorganic filler layer and the material for forming the resin layer are co-extruded through an extruder equipped with an annular die. Air is blown into the inside of the obtained cylindrical extrudate to cool it, and then, by cutting, the multilayered insect-repellent film of the present invention can be obtained.

[0069] Regarding the extrusion of the material for forming the inorganic filler layer by the inflation method, when compared with the case of extruding the material for forming the inorganic filler layer by other manufacturing methods (for example, the T-die method), the porosity of the formed inorganic filler layer tends to be higher (the density is lower). Therefore, by using the inflation method, the insect-repellent film of the present invention can be easily and reliably obtained.

[0070] <Second Embodiment: Method for Cultivating Plants>

[0071] The method for cultivating plants according to the second embodiment of the present invention uses the insect-repellent film in the first embodiment. The method for cultivating plants of the present invention can suppress the infestation of gastropods. The method for cultivating plants of the present invention is, for example, a method for cultivating grains, vegetables, and mushrooms. The method for cultivating plants of the present invention is preferably a method for cultivating crops (for example, strawberries, cabbages, shiitake mushrooms, and asparagus) that are vulnerable to the infestation of gastropods and have high commercial value.

[0072] The method for cultivating plants of the present invention preferably uses the organic farming method. In the organic farming method, the use of pesticides is restricted, so it is vulnerable to the infestation of gastropods. In contrast, in the case of cultivating plants of the present invention by the organic farming method, the infestation of gastropods can be suppressed without using pesticides. In addition, the organic farming method refers to an agricultural production method that minimizes the environmental impact of agricultural production on the basis of not using chemically synthesized fertilizers and pesticides and not using genetic recombination technology.

[0073] Hereinafter, an example of the usage method of the insect-repellent film (specifically, Figure 1 the insect-repellent film 10) according to the first embodiment in the method for cultivating plants of the present invention will be described. In one example of the usage method of the insect-repellent film 10, as Figure 4 shown, the insect-repellent film 10 is used as a ground cover film. Figure 4Represents the side of the soil S forming the ridge R. The ridge R is covered with the insect-repellent film 10. In the insect-repellent film 10, holes are formed near the top of the ridge R. In the ridge R, the plant P grows through the holes formed in the insect-repellent film 10. The insect-repellent film 10 inhibits gastropods living in the surrounding soil S from climbing onto the ridge R and approaching the plant P. As a result, the predation by gastropods can be inhibited. In addition, while inhibiting the predation by gastropods, the insect-repellent film 10 also plays the roles required for a general ground-covering film (for example, adjusting soil temperature, inhibiting weed propagation, and inhibiting soil from adhering to crops).

[0074] Another example of the usage method of the insect-repellent film (specifically, Figure 1 the insect-repellent film 10) related to the first embodiment in the cultivation method of the plant of the present invention will be described. In another example of the usage method of the insect-repellent film 10, as Figure 5 shown, a strip-shaped insect-repellent film 10 is used to surround the soil around the greenhouse G where the plant is planted. In this way, by surrounding the soil around the greenhouse G with the strip-shaped insect-repellent film 10, the invasion path I for gastropods to enter the inside of the greenhouse G from the outside is blocked. As a result, the number of gastropods growing inside the greenhouse G can be reduced, thereby inhibiting the predation by gastropods. In addition, Figure 5 the state where the plant is cultivated in the greenhouse G is taken as an example for illustration. However, in this usage method, as long as the strip-shaped insect-repellent film 10 is used to enclose the soil around the plant, it can also be applied to outdoor cultivation and the like.

[0075] The width of the strip-shaped insect-repellent film 10 is preferably 100 mm or more and 5000 mm or less, more preferably 500 mm or more and 2000 mm or less.

[0076] In the cultivation method of the plant of the present invention, the usage method of the insect-repellent film related to the above first embodiment is merely an example. The cultivation method of the plant of the present invention only needs to use the insect-repellent film related to the first embodiment, and the specific usage method is not limited. For example, in the cultivation of strawberries, sometimes the strawberries are cultivated in a state where the fruits are on the film. In the cultivation method of the present invention, the insect-repellent film related to the first embodiment can be used as the above-mentioned film. Also, in the cultivation method of the plant of the present invention, the insect-repellent film related to the first embodiment can be used as the ropes (for example, towing ropes and tying ropes) for supporting the plant and the fruit bags for wrapping the fruits.

[0077] [Examples]

[0078] Hereinafter, the present invention will be further described using examples. However, the present invention is not limited to the examples.

[0079] [Materials]

[0080] After kneading 30 parts by mass of polyethylene resin particles and 70 parts by mass of calcium carbonate particles using a twin-screw kneader, the mixture is sliced to obtain a masterbatch (calcium carbonate particles: 70% by mass). Next, 75 parts by mass of the masterbatch and 25 parts by mass of polyethylene resin particles are mixed to obtain a material for forming an inorganic filler layer.

[0081] By the inflation method, using the above-mentioned material for forming an inorganic filler layer, a single-layer insect-repellent film having an inorganic filler layer is formed. The thickness of the insect-repellent film is 40 μm. The content ratio of the inorganic filler in the insect-repellent film is 52.5% by mass. The content ratio of the inorganic filler in the insect-repellent film is 1.15 g / cm 3 . This is used as the insect-repellent film of Example 1.

[0082] Using the insect-repellent film of Example 1 as a ground covering film, a strawberry cultivation experiment is carried out. The strawberry cultivation experiment is carried out on a farm in Kasaoka City, Okayama Prefecture from March 2017 to June 2018. Specifically, in the greenhouse of the above-mentioned farm, strawberry seedlings are planted on ridges formed in the soil. Next, the above-mentioned ridges are covered with the insect-repellent film of Example 1. Next, holes are made in the area of the insect-repellent film of Example 1 that covers the strawberry seedlings to expose the strawberry seedlings. In this state, strawberries are planted and harvested.

[0083] When strawberries are eaten by slugs, the fruits turn green. The green strawberries cannot be shipped and sold. Based on this, the ratio of the yield of the green strawberries (strawberries eaten by slugs) to the total strawberry yield is measured and used as the "loss rate".

[0084] When using the insect-repellent film of Example 1 as a ground covering film for strawberry cultivation, the loss rate is basically 0%. In contrast, in strawberry cultivation using a common ground covering film up to the previous year (2016), the loss rate was about 15%. From this, it can be judged that using the insect-repellent film of Example 1 as a ground covering film can inhibit the predation of gastropods.

[0085] During the same period, the insect repellent effect of the insect repellent film of Example 1 processed into a strip (width 1000 mm) was confirmed. First, two greenhouses were prepared for strawberry cultivation. In one greenhouse (hereinafter, sometimes referred to as greenhouse A), the strip-shaped insect repellent film of Example 1 was set on the surrounding soil to enclose the greenhouse. In the other greenhouse (hereinafter, sometimes referred to as greenhouse B), the above operation was not performed. Next, the slugs inside the greenhouses A and B were removed. Then, one day later, the number of slugs inside the greenhouses was visually confirmed. As a result, no slugs were visually observed inside greenhouse A where the strip-shaped insect repellent film of Example 1 was set. On the other hand, in greenhouse B, there were more than 10 slugs per strawberry plant on average. That is to say, the strip-shaped insect repellent film of Example 1 inhibited the entry of slugs from the outside of greenhouse A into the inside of greenhouse A.

[0086] In summary, it was determined that the insect repellent film of Example 1 exhibited a high insect repellent effect against gastropods, thereby being able to inhibit the predation by gastropods.

[0087] Next, the relationship between the insect repellent effect against gastropods and the content ratio of the inorganic filler was studied. First, except for changing the following points, the insect repellent films of Comparative Examples 1 to 4 and Examples 2 to 4 were manufactured according to the manufacturing method of the insect repellent film of Example 1 described above. In the preparation of the material for forming the inorganic filler layer in the manufacture of the insect repellent films of Comparative Examples 1 to 4 and Examples 2 to 4, the usage amounts of the polyethylene resin particles (PE resin particles) and the masterbatch were as shown in Table 1 below.

[0088] Next, the following insect repellent effect confirmation test was carried out. First, the insect repellent films of Comparative Examples 1 to 4 and Examples 2 to 4 processed into 50 cm × 50 cm squares were used to cover the surface of the moist soil in the shade. One day later, each insect repellent film was removed, and the number of slugs (the slugs hiding under the insect repellent film) on the soil surface at the position covered by the insect repellent film was measured. The same test was carried out a total of 3 times on different days. Regarding the insect repellent effect against gastropods, when the measured number of slugs (the average value of 3 measurements) was 5 or less, it was judged to be good, and when it was 6 or more, it was judged to be bad. The results are shown in Table 1 below.

[0089] [Table 1]

[0090]

[0091] As shown in Table 1, in the insect-repellent films of Examples 2 to 4, the content ratio of calcium carbonate particles exceeds 50% by mass, and the insect-repellent effect on gastropods is good. On the other hand, in the insect-repellent films of Comparative Examples 1 to 4, the content ratio of calcium carbonate particles is 50% by mass or less, and the insect-repellent effect on gastropods is poor. Regarding the reason why the insect-repellent films of Comparative Examples 1 to 4 have a poor insect-repellent effect on gastropods, it can be judged that in addition to the low content ratio of calcium carbonate particles as the active ingredient, the high content ratio of the thermoplastic resin makes it difficult for calcium carbonate particles to exude.

[0092] Next, the relationship between the insect-repellent effect on gastropods and the density of the insect-repellent film was studied. First, except for changing the following points, the insect-repellent films of Comparative Examples 5 to 7 were manufactured according to the manufacturing method of the insect-repellent films of Examples 2 to 4 described above. In the manufacture of the insect-repellent films of Comparative Examples 5 to 7, when preparing the material for forming the inorganic filler layer, the usage amounts of polyethylene resin particles (PE resin particles) and masterbatch are as shown in Table 2 below. Also, in the manufacture of the insect-repellent films of Comparative Examples 5 to 7, a single-layer insect-repellent film having an inorganic filler layer was formed using the material for forming the inorganic filler layer by the T-die method (T method) instead of the inflation method (I method). The thickness of the insect-repellent films of Comparative Examples 5 to 7 is 40 μm. Next, the densities of the insect-repellent films of Comparative Examples 5 to 7 and Examples 2 to 4 were measured. Next, using the insect-repellent films of Comparative Examples 5 to 7 and Examples 2 to 4, the above-mentioned insect-repellent effect confirmation test was carried out. The evaluation results are shown in Table 2 below.

[0093] [Table 2]

[0094]

[0095] As shown in Table 2, the insect-repellent films of Examples 2 to 4 were manufactured by the inflation method, and the density is 1.05 g / cm 3 above 1.25 g / cm 3 below, and the insect-repellent films of Examples 2 to 4 have a good insect-repellent effect on gastropods. On the other hand, the insect-repellent films of Comparative Examples 5 to 7 were manufactured by the T-die method, and the density exceeds 1.25 g / cm 3 , and the insect-repellent films of Comparative Examples 5 to 7 have a poor insect-repellent effect on gastropods. Regarding the reason why the insect-repellent films of Comparative Examples 5 to 7 have a poor insect-repellent effect on gastropods, it can be judged that there is almost no gap between the calcium carbonate particles and the thermoplastic resin, making it difficult for the calcium carbonate particles to exude.

[0096] In summary, it can be judged that: in the insect-repellent film having an inorganic filler layer, by making the content ratio of the inorganic filler exceed 50.0% by mass and the density be 1.05 g / cm 3 above 1.25 g / cm 3The following can significantly improve the anthelmintic effect on gastropods.

[0097] 〔Industrial applicability〕

[0098] The anthelmintic film of the present invention can be used in cultivation.

Claims

1. A gastropod control film, which at least has an inorganic filler layer, the inorganic filler layer containing an inorganic filler and a thermoplastic resin, characterized in that, the inorganic filler layer is the outermost layer, the inorganic filler contains calcium carbonate particles, the content ratio of the inorganic filler in the gastropod control film exceeds 50.0% by mass, The density of the gastropod control film is 1.05 g / cm 3 or more and 1.25 g / cm 3 or less. the gastropod control film is obtained by the inflation method, and the calcium carbonate particles exude and are exposed on the surface of the inorganic filler layer.

2. The gastropod control film according to claim 1, characterized in that, the thermoplastic resin contains a polyolefin resin.

3. The gastropod control film according to claim 1 or 2, characterized in that, the inorganic filler layer further contains an additive, the content ratio of the additive is 0.5% by mass or more and 5.0% by mass or less.

4. The gastropod control film according to claim 3, characterized in that, the inorganic filler layer is an inorganic filler layer composed of the inorganic filler, the thermoplastic resin and an optional additive with a content ratio of 5.0% by mass or less.

5. A method for cultivating plants, using the gastropod control film according to any one of claims 1 to 4.

6. The method for cultivating plants according to claim 5, characterized in that, the gastropod control film is used as a ground covering film.

7. The method for cultivating plants according to claim 5, characterized in that, a strip-shaped gastropod control film is used to surround the soil around the plant.

8. The method for cultivating plants according to any one of claims 5 to 7, characterized in that, it is an organic agricultural planting method.

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