Agricultural film, and agricultural pest control film

Abstract

To provide an agricultural film having pest control effect.SOLUTION: Within the measurement wavelength range of 300 to 650 nm, an agricultural film has a reflectance peak between 500 to 600 nm. The average reflectance across the wavelength range of 500 to 600 nm is 10% or more to 50% or less.

Description

Technical Field

[0001] The present invention relates to an agricultural film, particularly an agricultural pest control film for preventing damage caused by agricultural pests.

Background Art

[0002] Conventionally, a method of cultivating agricultural crops by covering the field surface with a multi-film for the purpose of suppressing the growth of weeds in the field, adjusting water transpiration, and adjusting the ground temperature has been generally practiced. In such a multi-film, various studies have been made to impart an insect-proof effect. For example, in Patent Document 1, an insect-proof multi-film has been proposed in which a thermoplastic resin layer containing a pest repellent is laminated on at least one surface of a base material layer made of a thermoplastic resin containing aluminum powder.

[0003] However, in such a multi-film having a layer containing a pest repellent, since the pest repellent flows out (bleeds out) to the outside of the film over time, a long-term insect-proof effect cannot be obtained. In addition, there is also a problem that the antifouling property of the film is impaired by the pest repellent that has flowed out onto the film surface.

[0004] On the other hand, in recent years, the spread of a pest control system that does not rely solely on chemically synthesized pesticides, such as biopesticides that utilize natural enemies and various physical control means, has been expanding. Among these, an IPM system incorporating living mulch has been proposed for the purpose of popularizing and expanding comprehensive pest management techniques in open-field horticultural crops (such as cabbages and spring onions) (Non-Patent Document 1).

[0005] Living mulch mainly refers to another plant that is grown simultaneously so as to cover the ground surface during the growth of the crop to be cultivated. Plants used as living mulch are required to meet conditions such as "easy germination", "little nutritional competition with the main crop", "little risk of becoming a weed", and "uniformity", and barley is used in the cultivation of cabbages and onions.

[0006] In cabbage, it has been reported that introducing barley as a living mulch shows a high density suppression effect against cabbage white butterflies (cabbage worms), aphids, and onion thrips (Non-Patent Literature 1). In onions, it has been reported that introducing barley as a living mulch shows a high density suppression effect against thrips (Non-Patent Literature 1 and 2). Furthermore, it has been reported that barley also shows a density suppression effect against noctuid moths such as the cabbage looper.

[0007] While living mulch technology has advanced in this way, no attempts have been made to apply it to agricultural mulch film. [Prior art documents] [Patent Documents]

[0008] [Patent Document 1] Japanese Patent Application Publication No. 9-248069 [Non-patent literature]

[0009] [Non-Patent Document 1] Takayuki Sekine and Masaaki Osaka (2020) Plant Protection 74:680-686 [Non-Patent Document 2] Takayuki Sekine et al. (2021) Applied Entomology and Zoology56:59-68. [Disclosure of the Invention] [Problems that the invention aims to solve]

[0010] The present invention aims to provide an agricultural film that has an insect pest control effect. [Means for solving the problem]

[0011] It is believed that when insects search for crops to eat, they first visually explore the boundary between the crop and the ground to find the crop. The inventors considered whether the technology of living mulch could be realized with mulch film, and hypothesized that the visual disturbance of insects by living mulch is caused by the fact that insects cannot recognize the boundary between the crop and the ground because they are surrounded by the living mulch. Here, the visible light of insects is generally shifted 100 nm shorter than that of humans, and among them, cabbage leaves have a peak around 550 nm. Therefore, they thought that a film with reflective properties similar to that of plant leaves such as cabbage could cause a disturbance effect on insects. In other words, they thought that if a film resembling plant leaves is arranged to surround the crop, pests would not be able to recognize the boundary between the crop and the ground, but would strongly recognize the boundary between the film and the ground, explore that area for a certain period of time, give up, and move on without finding the crop. After diligent research, they completed the present invention.

[0012] In other words, the present invention is [1] An agricultural film having a reflectance peak in the 500-600 nm wavelength range within the measurement wavelength range of 300-650 nm, and an average reflectance of 10% or more and 50% or less across the 500-600 nm wavelength range. [2] An agricultural film [1] having an average reflectance of 15% or less over the wavelength range of 300-400 nm. [3] An agricultural film according to [1] or [2], wherein the average reflectance over the wavelength range of 600 to 650 nm is 5% or more and 40% or less. [4] The agricultural film described in [3], wherein the ratio of the average reflectance (A) over the wavelength range of 500-600 nm to the average reflectance (C) over the wavelength range of 600-650 nm is in the range of 1:0.6 to 1:0.8. [5] An agricultural film having a reflectance peak in the 500-600 nm wavelength range within the measurement wavelength range of 300-650 nm, and satisfying the following conditional equation. (A) > (C) > (B) ··· Formula (1) (A): Average reflectance over a wavelength range of 500 - 600 nm (B): Average reflectance over a wavelength range of 300 - 400 nm (C): Average reflectance over a wavelength range of 600 - 650 nm [6] An agricultural pest control film using the agricultural film according to any one of [1] to [5]. It is provided.

Advantages of the Invention

[0013] According to the present invention, an agricultural film having a pest control effect can be provided. In addition, since the agricultural film of the present invention does not contain a pest repellent like the prior art, there is no problem of a decrease in the pest control effect due to the bleed - out of the pest repellent, and thus it is possible to maintain the pest control effect during the period when it functions as a general agricultural film. Moreover, since the agricultural film of the present invention has an excellent pest control effect, it is possible to reduce the amount of pesticide used and provide a cultivation technique that takes environmental considerations into account.

Brief Description of the Drawings

[0014] [Figure 1] Reflectance characteristics of various crops and various films [Figure 2] Reflectance characteristics of various films (Examples 4 and 5, Comparative Example 3)

Modes for Carrying Out the Invention

[0015] Embodiment 1 One embodiment of the present invention is an agricultural film (hereinafter also referred to as "agricultural film 1 of the present invention") having a reflectance peak in the wavelength range of 500 - 600 nm in the measurement wavelength range of 300 - 650 nm, and the average reflectance over the wavelength range of 500 - 600 nm is 10% or more and 50% or less.

[0016] While not intended to be constrained by theory, the visible light range for insects is 300-650 nm; in other words, we believe that anything outside this range is not perceptible to insects. In the visible light range for insects, 300-650 nm, cabbage leaves have a peak reflectivity around 550 nm. Therefore, various films with reflective properties similar to plant leaves were investigated, and it was found that films with a reflectivity peak in the 500-600 nm wavelength range and an average reflectivity of 10% or more and 50% or less across the 500-600 nm wavelength range exhibit superior pest control effects. The agricultural film 1 of the present invention has excellent pest control effects due to having such optical properties. In this specification, reflectance refers to the sum of light reflected from the film and the object being covered, located outside the film. This includes both reflected light from the surface and interior of the film, and transmitted light that passes through the film after being reflected from the substrate, such as soil, that is covered by the film. Agricultural film 1 has a reflectance peak in the 500-600 nm wavelength range within the measurement wavelength range of 300-650 nm. We believe that having a reflectance peak in the 500-600 nm range allows the peak value of agricultural film 1 to be close to the peak reflectance value of the target plant's leaves, making it difficult for insects to recognize the boundary between the target plant's leaves and agricultural film 1, thus causing a confusion effect on insects. The reflectance peak of agricultural film 1 is preferably in the 510-590 nm range, and more preferably in the 520-580 nm range. Furthermore, in agricultural film 1, the average reflectance over the wavelength range of 500-600 nm is 10% or more and 50% or less. If the average reflectance is 10% or more, it is thought that insects can recognize it, and if it is 50% or less, the difference with the reflectance of the leaves of the target plant will not be large, which is thought to cause a confusion effect on insects and promote a pest repellent effect. The lower limit is preferably 12% or more, and more preferably 15% or more. The upper limit is preferably 48% or less, and more preferably 45% or less.

[0017] A preferred aspect of the agricultural film 1 of the present invention is that the average reflectance over the wavelength range of 300 to 400 nm is 15% or less. To enhance the insect-distracting effect, the overall reflective properties need to be made to resemble those of the leaves of the target plant, such as cabbage. It is believed that insect pests identify objects as plants in the ultraviolet wavelength range of 300-400 nm. For example, if the reflectivity is low, insect pests will identify it as an object such as a plant on the ground, while if the reflectivity is high, they will identify it as the sky or a water surface. To promote a visual confusion effect on pests, the material should preferably be 15% or less, preferably 13% or less, and even more preferably 10% or less, as it resembles the leaves of plants such as cabbage. If the reflectivity in the ultraviolet wavelength range of 300-400 nm is too high, pests may mistake it for the sky, causing them to invert their bodies and fall onto the film, which is undesirable because it traps the pests.

[0018] A preferred aspect of the agricultural film 1 of the present invention is that the average reflectance over the wavelength range of 600 to 650 nm is 5% or more and 40% or less. To enhance the insect-distracting effect, the overall reflective properties need to be made to resemble those of the leaves of the target plant, such as cabbage. It is believed that when reflectivity components in the long wavelength range of 600-650 nm are added, cabbage leaves and other plants appear brighter and younger to pests. As a result, agricultural film 1 appears more attractive to pests than the target plants that it is meant to protect. It is thought that pests strongly perceive the boundary between agricultural film 1 and the ground, explore that area for a certain period of time, then give up and move on without finding the target plants. Therefore, in order to promote the visual confusion effect on pests, we believe it is necessary to make the reflection characteristics on the longer wavelength side even more similar. If the reflectance in the 600-650 nm wavelength range is too low or too high, the disruption effect on pests will be inhibited, so a value of 5% to 40% is preferable, 5% to 30% is even preferable, and 5% to 20% is most preferable.

[0019] In a preferred aspect of the agricultural film 1 of the present invention, it is preferable that the ratio of the average reflectance (A) over the wavelength range of 500 to 600 nm to the average reflectance (A) over the wavelength range of 600 to 650 nm is within the range of 1:0.6 to 1:0.8. Reflected light in the 500-600 nm wavelength range is visible as a green component. Reflected light in the 600-650 nm wavelength range is visible as a yellow component. By combining both components, a yellow-green component is visible. We believe that the ratio of these two components is also important in order to make cabbage leaves and other leaves appear bright and young. If the average reflectance over the 600-650nm reflection region is 0.6 or higher compared to the average reflectance over the 500-600nm reflection region of 1, then the leaves of cabbage and other plants will not appear too dark green and will not be easily mistaken for mature leaves, thus appearing brighter and younger. An average reflectance of 0.62 or higher over the 600-650nm reflection region is more preferable, and 0.64 or higher is even more preferable. If the average reflectance over the 600-650nm reflection region is 0.8 or less compared to the average reflectance over the 500-600nm reflection region of 1, the yellow component of leaves such as cabbage will not become too strong, making them less likely to be recognized as old or withered leaves, thus making them appear brighter and younger. A more preferable average reflectance over the 600-650nm reflection region is 0.78 or less compared to the average reflectance over the 500-600nm reflection region of 1, and even more preferable is 0.76 or less.

[0020] The material used in the agricultural film 1 of the present invention is not particularly limited, and any known thermoplastic resin can be used. For example, polyvinyl chloride, polyethylene terephthalate, polyamide, polyethylene, polypropylene, polycarbonate, polyethylene naphthalate, ethylene-vinyl acetate copolymer, ionomer, acrylic acid ester, methacrylic acid ester, biodegradable resins such as aliphatic aromatic polyester and aliphatic polyester, and combinations of two or more of these can be used. Transparent films can be manufactured using these thermoplastic resins, and dyes and pigments that can be used in the agricultural film 1 of the present invention, described later, can be well dispersed in these thermoplastic resins. Therefore, by using these thermoplastic resins as the material for the film, it is possible to achieve reflective properties in which the average reflectance is 10% or more and 50% or less over a wavelength range of 500 to 600 nm. Biodegradable resins can be used in the present invention because they can be decomposed in the soil after being spread between agricultural films or cultivation ridges. Biodegradable resins can be used alone, or they can be used in combination with the above-mentioned thermoplastic resins (preferably polyethylene, polypropylene, polycarbonate, etc.) with biodegradable resins as the main component. From the perspective of soil decomposition, it is preferable to use biodegradable resin alone.

[0021] The biodegradable resin that can be used in the agricultural film 1 of the present invention is not particularly limited, and any biodegradable resin that is generally available can be used. Examples include polycaprolactone, polyvinyl alcohol, cellulose ester, lactic acid-based polyester resin, aliphatic polyester resin, and aliphatic aromatic polyester resin. Among these, aliphatic aromatic polyester resin, aliphatic polyester resin, and lactic acid-based polyester resin are preferable when considering productivity when manufacturing the film, workability when spreading it in the field, and biodegradability after use.

[0022] <Aliphatic aromatic polyester resin> The aliphatic aromatic polyester resin that can be used in the agricultural film 1 of the present invention contains aliphatic dicarboxylic acid units, aromatic dicarboxylic acid units, and linear aliphatic and / or alicyclic diol units, and the content of aromatic dicarboxylic acid units is 5 to 60 mol%, based on the total amount of aliphatic dicarboxylic acid units and aromatic dicarboxylic acid units (100 mol%).

[0023] The aliphatic aromatic polyester resin that can be used in the agricultural film 1 of the present invention specifically comprises, for example, an aliphatic diol unit represented by the following formula (1), an aliphatic dicarboxylic acid unit represented by the following formula (2), and an aromatic dicarboxylic acid unit represented by the following formula (3) as essential components.

[0024] -O-R1-O- (1) (In the formula, R1 represents a divalent linear aliphatic hydrocarbon group and / or a divalent alicyclic hydrocarbon group, and is not limited to one type when copolymerized.) -OC-R2-CO- (2) (In the formula, R2 represents either a direct bond or a divalent linear aliphatic hydrocarbon group and / or a divalent alicyclic hydrocarbon group, and is not limited to one type when copolymerized.) -OC-R3CO- (3) (In the formula, R3 represents a divalent aromatic hydrocarbon group, and is not limited to one type when copolymerized.)

[0025] The diol components that give the diol unit of formula (1) usually have 2 to 10 carbon atoms, and examples include ethylene glycol, 1,3-propanediol, 1,4-butanediol, and 1,4-cyclohexanedimethanol. Among these, diols with 2 to 4 carbon atoms are preferred, ethylene glycol and 1,4-butanediol are more preferred, and 1,4-butanediol is particularly preferred.

[0026] The dicarboxylic acid component that gives the dicarboxylic acid unit of formula (2) usually has 2 to 10 carbon atoms, and examples include succinic acid, adipic acid, suberic acid, sebacic acid, and dodecanediic acid. Among these, succinic acid or adipic acid is preferred.

[0027] Examples of aromatic dicarboxylic acid components that give the aromatic dicarboxylic acid unit of formula (3) include terephthalic acid, isophthalic acid, and naphthalenedicarboxylic acid, with terephthalic acid and isophthalic acid being preferred, and terephthalic acid being particularly preferred. Also, aromatic dicarboxylic acids in which part of the aromatic ring is substituted with a sulfonate are also included. Furthermore, two or more types of aliphatic dicarboxylic acid components, aliphatic diol components, and aromatic dicarboxylic acid components may be used.

[0028] The aliphatic aromatic polyester resin in the agricultural film 1 of the present invention may contain aliphatic oxycarboxylic acid units. Specific examples of aliphatic oxycarboxylic acids that provide aliphatic oxycarboxylic acid units include lactic acid, glycolic acid, 2-hydroxy-n-butyric acid, 2-hydroxycaproic acid, 6-hydroxycaproic acid, 2-hydroxy-3,3-dimethylbutyric acid, 2-hydroxy-3-methylbutyric acid, 2-hydroxyisocaproic acid, or mixtures thereof. Furthermore, these may be lower alkyl esters or intramolecular esters. If optical isomers exist for these, they may be D-forms, L-forms, or racemic mixtures, and may be in solid, liquid, or aqueous solution form. Among these, lactic acid or glycolic acid are preferred. These aliphatic oxycarboxylic acids can be used individually or as mixtures of two or more.

[0029] The amount of this aliphatic oxycarboxylic acid is preferably 0 to 30 mol%, and more preferably 0.01 to 20 mol%, of the total constituent components of the aliphatic aromatic polyester resin.

[0030] The melt flow rate (MFR) of the aliphatic aromatic polyester resin in the agricultural film 1 of the present invention is preferably 0.1 to 100 g / 10 min, more preferably 0.1 to 50 g / 10 min, and particularly preferably 0.1 to 30 g / 10 min, when measured at 190°C and a 2.16 kg load.

[0031] Specific examples of such aliphatic aromatic polyester resins include BASF's "Ecoflex," S-EnPol's "EnPol," and Xinjiang Blue Ridge Tunhe Polyester's "TH801T."

[0032] <Aliphatic polyester resin> The aliphatic polyester resin that can be used in the agricultural film 1 of the present invention may be an aliphatic polyester resin containing adipic acid units as dicarboxylic acid units, or an aliphatic polyester resin that does not contain adipic acid units as dicarboxylic acid units, etc.

[0033] The aliphatic polyester resin that can be used in the agricultural film 1 of the present invention is preferably an aliphatic polyester resin mainly composed of aliphatic diol units and aliphatic dicarboxylic acid units. Here, "main components" means that, based on the total monomer units constituting the aliphatic polyester (100 mol%), the aliphatic diol units and aliphatic dicarboxylic acid units make up 70 mol% or more, preferably 80 mol% or more, and more preferably 90 mol% or more.

[0034] Aliphatic polyester resins, for example, consist of a chain-like aliphatic and / or alicyclic diol unit represented by the following formula (4), and a chain-like aliphatic and / or alicyclic dicarboxylic acid unit represented by the following formula (5). -O-R4-O- (4) (In the formula, R4 represents a divalent linear aliphatic hydrocarbon group and / or a divalent alicyclic hydrocarbon group. When copolymerized, the resin may contain two or more types of R4.) -OC-R5-CO- (5) (In the formula, R5 represents a divalent linear aliphatic hydrocarbon group and / or a divalent alicyclic hydrocarbon group. When copolymerized, the resin may contain two or more types of R5.) In formulas (4) and (5) above, "divalent linear aliphatic hydrocarbon group and / or divalent alicyclic hydrocarbon group" means that both a divalent linear aliphatic hydrocarbon group and a divalent alicyclic hydrocarbon group may be included. Furthermore, "linear aliphatic and / or alicyclic" may be abbreviated as "aliphatic" below.

[0035] The aliphatic polyester resin contains 1,4-butanediol units as essential components, as the diol units of formula (4) above. The content of 1,4-butanediol units is preferably 30 to 60 mol%, particularly 40 to 50 mol%, based on the total monomer units constituting the aliphatic polyester resin (100 mol%). While there are no particular limitations on diol units other than 1,4-butanediol units, aliphatic diol units with 3 to 10 carbon atoms are preferred, and aliphatic diol units with 4 to 6 carbon atoms are particularly preferred. Specifically, examples include 1,3-propanediol and 1,4-hexanedimethanol. Two or more types of diol components can be used to provide the aliphatic diol units.

[0036] The aliphatic polyester resin further contains succinic acid units as essential components, specifically as dicarboxylic acid units. Furthermore, when an aliphatic polyester resin contains adipic acid as an essential component as a dicarboxylic acid unit, the content of adipic acid units is preferably 0.5 to 20 mol%, and more preferably 1 to 15 mol%, based on the total monomer units constituting the aliphatic polyester resin (100 mol%). While there are no particular limitations on dicarboxylic acid units other than succinic acid units and adipic acid units, aliphatic dicarboxylic acid units having 2 to 10 carbon atoms are preferred, and aliphatic dicarboxylic acid units having 4 to 8 carbon atoms are particularly preferred. Specifically, examples include suberic acid, sebacic acid, and dodecanediic acid. Two or more types of dicarboxylic acid components can also be used to provide the aliphatic dicarboxylic acid units.

[0037] Furthermore, the aliphatic polyester resin may contain aliphatic oxycarboxylic acid units. Specific examples of aliphatic oxycarboxylic acids that provide aliphatic oxycarboxylic acid units include lactic acid, glycolic acid, 2-hydroxy-n-butyric acid, 2-hydroxycaproic acid, 6-hydroxycaproic acid, 2-hydroxy-3,3-dimethylbutyric acid, 2-hydroxy-3-methylbutyric acid, 2-hydroxyisocaproic acid, etc., or their lower alcohols or intramolecular esters. If optical isomers exist for these, they may be D-forms, L-forms, or racemic mixtures, and may be in solid, liquid, or aqueous solution form. Among these, lactic acid or glycolic acid are particularly preferred. These aliphatic oxycarboxylic acids can be used individually or as a mixture of two or more. The content of aliphatic oxycarboxylic acid units is preferably 0 to 30 mol%, more preferably 0.01 to 20 mol%, and particularly preferably 0.01 to 10 mol%, based on the total monomer units constituting the aliphatic polyester resin (100 mol%). Specific examples of such aliphatic polyester resins include "BioPBS" from PTTMCC and "TH803S" from Xinjiang Blue Ridge Tunhe Polyester.

[0038] <Lactic acid-based polyester resin> The lactic acid-based polyester resin that can be used in the agricultural film 1 of the present invention can be L-lactic acid, D-lactic acid, DL-lactic acid or mixtures thereof, or homopolymers or copolymers of lactide. The lactic acid-based polyester resin can be produced directly from these raw materials by dehydration condensation or ring-opening polymerization of lactide, but the production method is not particularly limited. In addition, other hydroxycarboxylic acids, aliphatic polyhydric alcohols, aliphatic polybasic acids, etc., other than lactic acid may be copolymerized to the extent that the properties of the lactic acid-based polyester resin are not impaired. Specific examples of such lactic acid-based polyester resins include Nature Works' "Ingeo Biopolymer," Zhejiang Haizheng Biomaterials' "REVODE," and Total Corbion's "Luminy." Furthermore, the lactic acid-based polyester resin produced in this manner can also be used as a raw material that has been pre-mixed with other aliphatic polyester resins or aliphatic aromatic polyester resins. Specific examples of mixed resins with lactic acid-based polyester resins include BASF's "Ecovio F Blend C2224".

[0039] In the agricultural film 1 of the present invention, various dyes and pigments can be added in predetermined amounts, as long as they can achieve a reflectivity characteristic of an average reflectance of 10% or more and 50% or less over a wavelength range of 500 to 600 nm. Examples of dyes and pigments that can be used in the agricultural film 1 of the present invention include oxides such as zinc oxide, iron oxide, and titanium dioxide; inorganic pigments such as ultramarine, Prussian blue, viridian, carbon black, and titanium black; and organic pigments such as azo pigments and phthalocyanine pigments. It is preferable to use a combination of these. In particular, by combining white colorants such as zinc oxide, titanium dioxide, and barium sulfate with green colorants such as viridian, pigment green, and phthalocyanine green, it becomes easier to produce agricultural films with an average reflectance of 10% or more and 50% or less over the wavelength range of 500-600 nm. When using a combination of white and green colorants, only this combination of colorants may be used as the pigment, or a predetermined amount of carbon black or other pigments may be added in addition to this combination of colorants. Furthermore, for example, when titanium dioxide is used as a white coloring agent and copper phthalocyanine as a green coloring agent, the preferred content ratio of titanium dioxide to copper phthalocyanine is 90:10 to 99:1, and more preferably 98:2 to 93:7. Furthermore, the amount of coloring agents such as dyes and pigments (the total amount if two or more dyes and pigments are used) is usually 1 to 20 parts by weight, preferably 3 to 15 parts by weight, and more preferably 5 to 12 parts by weight, per 100 parts by weight of the total weight of the thermoplastic resin that is the material of the agricultural film 1.

[0040] In one preferred aspect of the agricultural film 1 of the present invention, a white colorant is used in combination with a colorant of another color (dye or pigment). Here, zinc oxide, titanium dioxide, calcium carbonate, barium sulfate, lithopone, etc., can be used as the white colorant. Another preferred aspect of the agricultural film 1 of the present invention is the use of titanium dioxide in combination with other pigments.

[0041] <Other ingredients> The agricultural film 1 of the present invention may further contain various conventionally known additives, to the extent that they do not impair the effects of the present invention. Examples of additives include other stabilizers, impact resistance improvers, crosslinking agents, fillers, foaming agents, plate-out prevention agents, surface treatment agents, fluorescent agents, antifungal agents, antibacterial agents, bactericidal agents, metal deactivators, crystal nucleating agents, antioxidants, slip agents, antiblocking agents, ultraviolet absorbers, lightfast agents, plasticizers, stabilizers, colorants, flame retardants, mold release agents, antistatic agents, antifogging agents, surface wetting improvers, incineration aids, dispersants, surfactants, hydrolysis inhibitors, and processing aids. These may be used individually or in combination of two or more. Among these, slip agents, antiblocking agents, ultraviolet absorbers, and lightfast agents are particularly preferred.

[0042] Examples of slip agents include unsaturated fatty acid amides and unsaturated fatty acid bisamides, which consist of unsaturated fatty acids with 6 to 30 carbon atoms, with erucic acid amide and erucic acid bisamide being preferred.

[0043] Examples of antiblocking agents include saturated fatty acid amides with 6 to 30 carbon atoms, or saturated fatty acid bisamides (e.g., stearate amide, stearate bisamide), methylolamide, ethanolamide, natural silica, synthetic silica, synthetic zeolite, talc, etc.

[0044] Examples of UV absorbers include triazine-based, benzophenone-based, benzotriazole-based, salicylic acid-based, and cyanoacrylate-based UV absorbers, among which triazine-based, benzotriazole-based, or benzophenone-based UV absorbers are preferred.

[0045] Examples of triazine-based UV absorbers that can be used include the compound represented by 2-[4,6-bis(2,4-dimethylphenyl)1,3,5-triazin-2-yl]-5-(octyloxy)phenol: CAS Number 2725-22-6 (e.g., Cytec's CYASORB UV-1164), 2-(4,6-diphenyl-1,3,5-triazin-2-yl)-5-[(hexyl)oxy]-phenol: CAS Number 147315-50-2 (e.g., BASF Japan's Tinuvin 1577FF), and 2-[4,6-bis(diphenyl-4-yl)-1,3,5-triazin-2-yl]-5-[(2-ethylhexyl)oxy]-phenol (e.g., BASF Japan's Tinuvin 1600).

[0046] Examples of benzotriazole-based or benzophenone-based UV absorbers include 2-[5-chloro(2H)-benzotriazole-2-yl]-4-methyl6-(tert-butyl)phenol, 2-[2-hydroxy-3,5-bis(α,α-dimethylbenzyl)phenyl]-2H-benzotriazole, octabenzone, 2,2'-dihydroxy-4-4'-dimethoxybenzophenone, and 2,2'-4,4'-tetrahydrobenzophenone.

[0047] As lightfastening agents, bis(2,2,6,6-tetramethyl-4-piperidyl) sebacate, bis(1,2,2,6,6-pentamethyl-4-piperidyl) sebacate, bis(1-octyloxy-2,2,6,6-tetramethyl-4-piperidyl) sebacate, 2-(3,5-di-t-butyl-4-hydroxyphenyl)-2-n-butyl-bis(2,2,6,6-tetramethyl-4-piperidyl) malonate, 2-(3,5-di-t-butyl-4 -Hydroxyphenyl)-2-n-butyl-bis(1,2,2,6,6-pentamethyl-4-piperidyl)malonate, 2-(3,5-di-t-butyl-4-hydroxybenzyl)-2-n-butyl-bis(2,2,6,6-tetramethyl-4-piperidyl)malonate, 2-(3,5-di-t-butyl-4-hydroxybenzyl)-2-n-butyl-bis(1,2,2,6,6-pentamethyl-4-piperidyl)malonate, tetrakis(2,2 ,6,6-tetramethyl-4-piperidyl)-1,2,3,4-butanetetracarboxylate, tetrakis(1,2,2,6,6-pentamethyl-4-piperidyl)-1,2,3,4-butanetetracarboxylate, mixed(2,2,6,6-tetramethyl-4-piperidyl / tridecyl)-1,2,3,4-butanetetracarboxylate, mixed(1,2,2,6,6-pentamethyl-4-piperidyl / tridecyl)-1,2,3 ,4-butanetetracarboxylate, mixed {2,2,6,6-tetramethyl-4-piperidyl / β,β,β',β'-tetramethyl-3,9-[2,4,8,10-tetraoxaspiro[5.5]undecane]diethyl}-1,2,3,4-butanetetracarboxylate, mixed {1,2,2,6,6-pentamethyl-4-piperidyl / β,β,β',β'-tetramethyl-3,9-[2,4,8,10-tetraoxaspiro[5.5]Undecane]diethyl}-1,2,3,4-butanetetracarboxylate, 1,2-bis(3-oxo-2,2,6,6-tetramethyl-4-piperidyl)ethane, 1-(3,5-di-t-butyl-4-hydroxyphenyl)-1,1-bis(2,2,6,6-tetramethyl-4-piperidyloxycarbonyl)pentane, poly[1-oxyethylene(2,2,6,6-tetramethyl-1,4-piperidyl)oxysuccinyl], poly[2-(1,1,4-trimethylbutylimino)-4,6-triazinediyl-(2,2,6,6-tetramethyl-4-piperidyl)iminohexamethylene-(2,2,6,6-tetramethyl-4-piperidyl)imino], N,N'-bis(3-aminopropyl) Examples include ethylenediamine-2,4-bis[N-butyl-N-(2,2,6,6-tetramethyl-4-piperidyl)amino]-6-chloro-1,3,5-triazine condensate and its N-methyl compound, polycondensate of succinic acid and 1-(2-hydroxyethyl)-4-hydroxy-2,2,6,6-tetramethylpiperidine, poly[{6-((1,1,3,3-tetramethylbutyl)amino-1,3,5-triazine2,4-diyl}{(2,2,6,6-tetramethyl-4-piperidyl)imino}hexamethylene{((2,2,6,6-tetramethyl-4-piperidyl)imino}], olefin (C20-C24)-maleic anhydride-4-amino-2,2,6,6-tetramethylpiperidine copolymer, etc.

[0048] Antioxidants include BHT, 2,2'-methylenebis(4-methyl-6-tert-butylphenol), pentaerythritol tetrakis[3-(3,5-di-tert-butyl-4-hydroxyphenyl)propionate], 3,3',3”,5,5',5”-hexa-tert-butyl-α,α',α”-(mesitylene-2,4,6-triyl)tri-p-cresol, octadecyl-3-(3,5-di-tert-butyl-4-hydroxyphenyl)propionate, and 1,3,5- Lith[(4-tert-butyl-3-hydroxy-2,6-xylyl)methyl]-1,3,5-triazine-2,4,6(1H,3H,5H)-trione, 1,3,5-tris(3,5-di-tert-butyl-4-hydroxybenzyl)-1,3,5-triazine-2,4,6(1H,3H,5H)-trione, calcium diethylbis[{3,5-bis(1,1-dimethylethyl)-4-hydroxyphenyl}methyl]phosphonate, bis(2,2'-dihydroxy-3,3'-di-ter Hindered phenol antioxidants such as t-butyl-5,5'-dimethylphenyl)ethane, N,N'-hexane-1,6-diyrbis[3-(3,5-di-tert-butyl)-4-hydroxyphenyl]propionamide, n-octadecyl 3-(3',5'-di-t-butyl-4'-hydroxyphenyl)propionate, tridecyl phosphite, diphenyldecyl phosphite, tetrakis(2,4-di-tert-butylphenyl)[1,1-biphenyl]-4,4'-diyrbis Examples include phosphorus-based antioxidants such as phosphonite, bis[2,4-bis(1,1-dimethylethyl)-6-methylphenyl]ethyl ester phosphorous acid, and bis(2,4-di-tert-butylphenyl)pentaerythritol diphosphite; lactone-based antioxidants such as reaction products of 3-hydroxy-5,7-di-tert-butyl-furan-2-one and xylene; sulfur-based antioxidants such as dilauryl thiodipropionate and distearyl thiodipropionate; and mixtures of two or more of these.

[0049] Examples of stabilizers include fatty acid metal salts. The fatty acid component of fatty acid metal salts is a chain-like carboxylic acid, usually having 6 to 30 carbon atoms and containing a carboxyl group. It may be linear or branched, and may contain only saturated bonds or only unsaturated bonds. Specific examples of fatty acids include caproic acid, caprylic acid, capric acid, lauric acid, myristic acid, palmitic acid, stearic acid, arachidic acid, behenic acid, montanic acid, palmitoleic acid, oleic acid, eicosenoic acid, erucic acid, elaidic acid, trans-11-eicosenoic acid, trans-13-docosenoic acid, linoleic acid, linolenic acid, ricinoleic acid, and erucic acid.

[0050] On the other hand, preferred metal atoms are those belonging to groups 1A, 2A, 2B, and 3B of the periodic table. Preferred examples include sodium, potassium, calcium, magnesium, barium, aluminum, and zinc.

[0051] Examples of fatty acid metal salts include calcium stearate, magnesium stearate, barium stearate, aluminum stearate, zinc stearate, calcium laurate, magnesium laurate, aluminum laurate, and sodium montanoate. These may be used individually or in combination of two or more. Among these, calcium stearate, magnesium stearate, aluminum stearate, calcium laurate, magnesium laurate, and aluminum laurate are preferred.

[0052] Examples of dispersants include low molecular weight resin waxes such as ethylenebisamide, polyethylene wax, and polypropylene wax, and ester-based waxes such as montan wax.

[0053] Furthermore, the agricultural film 1 of the present invention may contain an inorganic filler. The amount of inorganic filler is preferably 0.05 to 10 parts by weight, more preferably 0.1 to 9.5 parts by weight, and even more preferably 0.5 to 9.0 parts by weight, based on 100 parts by weight of the total weight of the resin component. By including the inorganic filler as described above, it is possible to obtain better moldability.

[0054] Inorganic fillers that can be used in the present invention include silica, mica, talc, titanium dioxide, calcium carbonate, diatomaceous earth, allophane, bentonite, potassium titanate, zeolite, sepiolite, smectite, kaolin, kaolinite, glass, limestone, carbon, wollastonite, calcined perlite, silicates such as calcium silicate and sodium silicate, hydroxides such as aluminum oxide, magnesium carbonate, and calcium hydroxide, ferric carbonate, zinc oxide, iron oxide, aluminum phosphate, and barium sulfate. One of these may be used alone, or two or more may be used in combination.

[0055] Furthermore, the agricultural film 1 of the present invention may contain biodegradable resins and natural products, such as polycaprolactone, polyamide, polyvinyl alcohol, cellulose esters, or fine powders of animal / plant materials such as starch, cellulose, paper, wood flour, chitin / chitosan, coconut shell powder, walnut shell powder, or mixtures thereof, to the extent that they do not impair the effects of the present invention.

[0056] When producing the agricultural film 1 of the present invention, a general method for mixing the thermoplastic resin composition can be used. Specifically, pellets, powders, or solid fragments can be dry-mixed in a Henschel mixer or ribbon mixer, and then supplied to a known melt mixer such as a single-screw or twin-screw extruder, a Banbury mixer, a kneader, or a mixing roll for melt mixing.

[0057] Methods for forming films from thermoplastic resin compositions can suitably include, for example, melt extrusion molding (including T-die method and inflation method), calendering, roll processing, extrusion molding, blow molding, molten casting, pressure molding, paste processing, and powder molding.

[0058] The thickness of the agricultural film 1 of the present invention is preferably 5 μm to 50 μm, preferably 5 μm to 40 μm, more preferably 5 μm to 35 μm, and particularly preferably 5 μm to 30 μm. By setting the thickness of the agricultural film 1 within this range, the molding of the film can be made more stable, and insufficient strength when used for stretching work can be suppressed.

[0059] The agricultural film 1 of the present invention may be a single layer or a multi-layer structure. When multiple layers are used, a black layer may be provided on the back side of agricultural film 1 as a layer to block light transmission. By providing a black layer, almost 100% of transmitted light can be blocked, thereby enhancing the weed control effect.

[0060] Embodiment 2 Another embodiment of the present invention has a measurement wavelength range of 300 to 650 nm, with a reflectance peak in the wavelength range of 500 to 600 nm. An agricultural film that satisfies the following conditions (hereinafter also referred to as "Agricultural Film 2 of the present invention"). (A)>(C)>(B)...Equation (1) (A): Average reflectance over the wavelength range of 500-600 nm (B): Average reflectance over the wavelength range of 300-400 nm (C): Average reflectance over the wavelength range of 600-650 nm

[0061] Although not intended to be constrained by theory, cabbage leaves have a peak around 550 nm and show lower average reflectance values ​​on the longer and shorter wavelength sides compared to the 500-600 nm wavelength region. Therefore, various studies were conducted on films with reflective properties similar to plant leaves, and an agricultural film (hereinafter also referred to as "Agricultural Film 2 of the present invention") was found to have a reflectance peak in the 500-600 nm wavelength region and satisfy the following conditional equation. (A)>(C)>(B)...Equation (1) (A): Average reflectance over the wavelength range of 500-600 nm (B): Average reflectance over the wavelength range of 300-400 nm (C): Average reflectance over the wavelength range of 600-650 nm We also found that it has excellent pest control effects in this area. The agricultural film 2 of the present invention has excellent pest control effects due to having such optical properties.

[0062] The material used for the agricultural film 2 of the present invention is not particularly limited, and any known thermoplastic resin can be used. For example, polyvinyl chloride, polyethylene terephthalate, polyamide, polyethylene, polypropylene, polycarbonate, polyethylene naphthalate, ethylene-vinyl acetate copolymer, ionomer, acrylic acid ester, methacrylic acid ester, and biodegradable resins such as aliphatic aromatic polyester and aliphatic polyester can be used. Among these, biodegradable resins can be preferably used in the present invention because they can be decomposed in the soil after being used as mulch film or between cultivation ridges.

[0063] The biodegradable resin that can be used in the agricultural film 2 of the present invention is not particularly limited, and any biodegradable resin that is generally available can be used. Examples include polycaprolactone, polyvinyl alcohol, cellulose ester, lactic acid-based polyester resin, aliphatic polyester resin, and aliphatic-aromatic polyester resin. Among these, aliphatic-aromatic polyester resin, aliphatic polyester resin, and lactic acid-based polyester resin are preferable when considering productivity when manufacturing the film, workability when spreading it in the field, and biodegradability after use. Aliphatic aromatic polyester resins, aliphatic polyester resins, and lactic acid polyester resins can be the same as those detailed in agricultural film 1 of the present invention.

[0064] In the agricultural film 2 of the present invention, various dyes and pigments can be added in predetermined amounts, as long as they can achieve the relationship equation (1) for average reflectance in a specific wavelength range. Examples of dyes and pigments that can be used in the agricultural film 2 of the present invention include oxides such as zinc oxide, iron oxide, and titanium dioxide; inorganic pigments such as ultramarine, Prussian blue, viridian, carbon black, and titanium black; and organic pigments such as azo pigments and phthalocyanine pigments. It is preferable to use a combination of these. In particular, by using a combination of white colorants such as zinc oxide, titanium dioxide, and barium sulfate, and black colorants such as carbon black, titanium black, and acetylene black, it becomes easier to produce an agricultural film with a reflectance of about 10% over a wavelength range of 500 to 600 nm. When using a combination of white colorants and green colorants, only this combination of colorants may be used as the pigment, or carbon black or other pigments may be added in predetermined amounts in addition to this combination of colorants. Furthermore, for example, when titanium dioxide is used as a white coloring agent and copper phthalocyanine as a green coloring agent, the preferred content ratio of titanium dioxide to copper phthalocyanine is 90:10 to 99:1, and more preferably 98:2 to 93:7. Furthermore, the amount of dyes and pigments used (the total amount if two or more types of dyes and pigments are used) is usually 1 to 20 parts by weight, preferably 3 to 15 parts by weight, and more preferably 5 to 12 parts by weight, per 100 parts by weight of the total weight of the thermoplastic resin that is the material of the agricultural film 2.

[0065] In one preferred aspect of the agricultural film 2 of the present invention, a white colorant is used in combination with a colorant of another color (dye or pigment). Here, zinc oxide, titanium dioxide, calcium carbonate, barium sulfate, lithopone, etc., can be used as the white colorant. Furthermore, in another preferred aspect of the agricultural film 2 of the present invention, titanium dioxide and other pigments are used in combination.

[0066] The agricultural film 2 of the present invention may further contain various conventionally known additives, provided that they do not impair the effects of the present invention. Examples of additives include crystal nucleating agents, antioxidants, antiblocking agents, slip agents, ultraviolet absorbers, lightfastness agents, plasticizers, stabilizers, colorants, flame retardants, mold release agents, antistatic agents, antifogging agents, surface wetting improvers, incineration aids, lubricants, dispersants, various surfactants, and hydrolysis inhibitors. These may be used individually or in combination of two or more. Among these, slip agents, antiblocking agents, and ultraviolet absorbers are particularly preferable. The additives used in the agricultural film 2 of the present invention can be the same as those detailed in the agricultural film 1 of the present invention.

[0067] When producing the agricultural film 2 of the present invention, a general method for mixing the thermoplastic resin composition can be used. Specifically, pellets, powders, or solid fragments can be dry-mixed in a Henschel mixer or ribbon mixer, and then supplied to a known melt mixer such as a single-screw or twin-screw extruder, a Banbury mixer, a kneader, or a mixing roll for melt mixing.

[0068] Methods for forming films from thermoplastic resin compositions can suitably include, for example, melt extrusion molding (including T-die method and inflation method), calendering, roll processing, extrusion molding, blow molding, molten casting, pressure molding, paste processing, and powder molding.

[0069] The thickness of the agricultural film 2 of the present invention is preferably 5 μm to 50 μm, more preferably 5 μm to 40 μm, even more preferably 5 μm to 35 μm, and particularly preferably 5 μm to 30 μm. By setting the thickness of the agricultural film within this range, the molding of the film can be made more stable, and insufficient strength when used for stretching work can be suppressed.

[0070] The agricultural film 2 of the present invention may be a single layer or a multi-layer structure. When a multi-layer structure is used, a black layer may be provided on the back side of agricultural film 2 as a layer to block light transmission. By providing a black layer, almost 100% of transmitted light can be blocked, thereby enhancing the weed control effect.

[0071] Agricultural pest control film Another embodiment of the present invention is an agricultural pest control film using agricultural film 1 or agricultural film 2 of the present invention.

[0072] The present invention will be described more specifically below with reference to examples, but the present invention is not limited to these examples. [Examples]

[0073] [Evaluation Method] (1) Method for measuring reflectance (unit: %) Measurements were taken in a darkroom using a spectrometer, Asahi Spectrometer HSU-100S, and a compact xenon light source, Asahi Spectrometer LAX-C100. The measurement conditions were as follows: L1: 50, Measurement mode: Object color measurement, Exposure time (white reference plate): 4000, Exposure time (sample measurement): Automatic detection, Number of integrations: 1, Correction data: SRS-99-010-OD95C-8820, Limit data: Not specified. The film to be measured was placed on a black, non-reflective flocked cloth, and the number of photons in the reflected light was measured at 1 nm intervals using an integrating sphere. (See Figures 1 and 2) From the aforementioned measurements, the peak reflectance value at 500-600 nm, the average reflectance at 500-600 nm (A), the average reflectance at 300-400 nm (B), and the average reflectance at 600-650 nm (C) were read.

[0074] (2) Confirmation of the pest-suppressing effect of cabbage (a), (b), (c), (d) On September 6, 2021, agricultural film was laid out on farmland in Natori City, Miyagi Prefecture, and cabbage was cultivated. From September 6 to November 1 (a total of 57 days), the number of target pests on the cabbage was visually counted at predetermined intervals, and the cumulative number of infested plants per 24 plants (eggs + larvae, and all developmental stages in the case of aphids) was calculated and evaluated according to the following criteria. (a) Target pest: Cabbage white butterfly ○: The number of parasitic cabbage white butterflies is less than 120. △: The number of parasitic cabbage white butterflies is 120 or more, but less than 150. ×: The number of parasitic cabbage white butterflies is 150 or more. (b) Target pests: Locusts ○: The number of parasitic moths is less than 320. △: The number of parasitic moths is 320 or more, but less than 350. ×: The number of parasitic moths is 350 or more. (c) Target pest: Diamondback moth ○: The number of diamondback moth parasites is less than 10. △: Number of diamondback moth parasites is 10 or more but less than 20. ×: The number of diamondback moth parasites is 20 or more. (d) Target pests: Aphids ○: The number of aphids parasitizing the insect is less than 200. △: The number of aphids parasitizing the plant is between 200 and 250. ×: The number of aphids parasitizing the insect is 250 or more.

[0075] (3) Confirmation of the pest-suppressing effect of radishes (e), (f) On September 6, 2021, agricultural film was laid out on farmland in Natori City, Miyagi Prefecture, and radishes were cultivated. From September 6 to October 8 (a total of 33 days), the number of target radish pests was visually counted at predetermined intervals, and the cumulative number of infested plants (eggs + larvae) per 24 plants was calculated and evaluated according to the following criteria. (e) Target pest: Cabbage white butterfly ○: The number of parasitic insects in the cabbage white butterfly is less than 5. △: The number of parasitic cabbage white butterflies is 5 or more but less than 10. ×: More than 10 parasitic cabbage white butterflies (f) Target pests: Locusts ○: The number of parasitic moths is less than 20. △: Number of parasitic moths is 20 or more but less than 30. ×: The number of parasitic moths is 30 or more.

[0076] (4) Confirmation of the pest-suppressing effect of cabbage (g), (h) On August 30, 2022, agricultural film was laid out on farmland in Natori City, Miyagi Prefecture, and cabbage was cultivated. From August 30 to November 7 (a total of 69 days), the number of cabbage target pests was visually counted at predetermined intervals, and the cumulative number of infested plants (number of eggs laid, or all developmental stages in the case of aphids) per 36 plants was calculated and evaluated according to the following criteria. (g) Target pest: Cabbage white butterfly ○: The number of parasitic cabbage white butterflies is less than 150. △: The number of parasitic cabbage white butterflies is between 150 and 300. ×: The number of parasitic cabbage white butterflies is 300 or more. (h) Target pests: Aphids ○: The number of aphids parasitizing the insect is less than 200. △: The number of aphids parasitizing the plant is between 200 and 500. ×: The number of aphids parasitizing the plant is 500 or more.

[0077] [Materials used] The materials used in the examples are as follows.

[0078] <Biodegradable resin> • Aliphatic aromatic polyester resin (manufactured by Xinjiang Blue Ridge Tunhe Polyester, product name "TH801T") • Aliphatic polyester resin (manufactured by Mitsubishi Chemical Corporation, product name "BioPBS") <Polyethylene resin> • Polyethylene resin (manufactured by Nippon Polyethylene Co., Ltd., product name "Novatec LD LF240") <Coloring agent> Titanium dioxide, copper phthalocyanine, carbon black, and other pigments were added using the following masterbatch. <Masterbatch of green pigments> We used ink manufactured by Tokyo Ink Co., Ltd. (Grade name: GPM 6CA026GREEN). Biodegradable resin 38% by mass Titanium dioxide 50% by mass Copper phthalocyanine 3.5% by mass Carbon black 0.5% by mass Other pigments 8% by mass <Masterbatch of white pigments> We used a product manufactured by Dainichi Seika Kogyo Co., Ltd. (Grade name: BR-RM 17N3940 WH). Biodegradable resin 40% by mass Titanium dioxide 60% by mass <Black Masterbatch> We used ink manufactured by Tokyo Ink Co., Ltd. (Grade name: GPM 9BH092 BLACK AL). Biodegradable resin 60% by mass Carbon black 40% by mass <Other additives> The following masterbatch was used to add additives including talc, UV absorbers, and light stabilizers. <Masterbatch of Additive 1> Aliphatic aromatic polyester resin (manufactured by Xinjiang Blue Ridge Tunhe Polyester, product name "TH801T") 49.6% by mass, Talc (IMERYS brand, product name "Misttron 850JS") 40% by mass, Additives including UV absorbers and light stabilizers: 10.4% by mass <Masterbatch for Additive 2> Biodegradable resin (manufactured by Mitsubishi Chemical Corporation, product name "BioPBS") 87.5% by mass Additives including UV absorbers and light stabilizers: 12.5% ​​by mass

[0079] [Method for forming a film] After blending the materials, the cylinder and die temperatures were set to the melting temperature of the aliphatic aromatic polyester resin + 40 to 60°C, and an 18 μm thick film was formed using an inflation molding machine from Sumitomo Heavy Industries Modern.

[0080] [Example 1] As a biodegradable resin, 92.3 parts by weight of aliphatic aromatic polyester and 7.7 parts by weight of aliphatic polyester resin were mixed to a total of 100 parts by weight, and various pigments and additives were added in the amounts shown in Table 1. A film was then formed using the film formation method described above. The obtained film was stretched and evaluated according to (a) to (f) above. In the measurement wavelength range of 300-650 nm, the peak in the 500-600 nm wavelength range was around 535 nm, and the average reflectance across the 500-600 nm wavelength range was 41.2%. On cabbage leaves, there were 98 cabbage white butterflies, 339 loopers, 8 diamondback moths, and 82 aphids. On radish leaves, there were 4 cabbage white butterflies and 13 loopers. The sample exhibited a peak value in the 500-600nm wavelength range, and its average reflectance across this range was between 10% and 50%, closely matching the reflectivity characteristics of the target plant's leaves. This confirmed its pest-suppressing effect. Because the average reflectance across the 500-600nm wavelength range is relatively high at 41.2%, it was confirmed to be particularly effective against diurnal pests such as cabbage white butterflies. The average reflectance across the 300-400nm wavelength range was 9.5%, and since the average reflectance is less than 15%, it is presumed that this suppressed the retention of pests on the film, leading to a pest control effect. The average reflectance over the 600-650nm wavelength range was 30.1%, and since the average reflectance is between 5% and 40%, it is presumed that the leaves of the target plant, such as cabbage, were bright, and even in the young leaf stage, the light was able to promote a visual confusion effect on pests, leading to a pest suppression effect. The ratio of the average reflectance over the 500-600 nm wavelength range to the average reflectance over the 600-650 nm wavelength range was 1:0.73. Since the ratio of the average reflectance over the 600-650 nm wavelength range to the average reflectance over the 500-600 nm wavelength range is between 0.6 and 0.8, it is presumed that the leaves of the target plant were bright, and even in the young leaf stage, they were able to promote a visual confusion effect on pests, leading to a pest suppression effect. The reflectance peaked in the 500-600 nm wavelength range (43.4%), and the average reflectance over the 500-600 nm wavelength range (A) was 41.2%, the average reflectance over the 300-400 nm wavelength range (B) was 9.5%, and the average reflectance over the 600-650 nm wavelength range (C) was 30.1%, satisfying the relationship (1) (A)>(C)>(B).

[0081] [Example 2] As a biodegradable resin, 95.9 parts by weight of aliphatic aromatic polyester and 4.1 parts by weight of aliphatic polyester resin were mixed to a total of 100 parts by weight, and various pigments and additives were added in the amounts shown in Table 1. A film was then formed using the film formation method described above. The obtained film was stretched and evaluated according to (a) to (f) above. In the measurement wavelength range of 300-650 nm, the peak in the 500-600 nm wavelength range was around 542 nm, and the average reflectance across the 500-600 nm wavelength range was 31.9%. On cabbage leaves, there were 112 cabbage white butterflies, 305 loopers, 7 diamondback moths, and 159 aphids. On radish leaves, there were 7 cabbage white butterflies and 7 loopers. The sample exhibited a peak value in the 500-600nm wavelength range, and its average reflectance across this range was between 10% and 50%, closely matching the reflectivity characteristics of the target plant's leaves. This confirmed its pest-suppressing effect. The average reflectance across the 500-600nm wavelength range is 31.9%, which is in the middle range, allowing us to confirm a balanced effect against all pests. The average reflectance over the 300-400nm wavelength range was 8.2%, and since the average reflectance is less than 15%, it is presumed that this suppressed the retention of pests on the film, leading to the pest control effect. The average reflectance over the 600-650nm wavelength range was 18.7%, and since the average reflectance is between 5% and 40%, it is presumed that the leaves of the target plant, such as cabbage, were bright, and even in the young leaf stage, the light was able to confuse the eyes of pests, leading to a pest control effect. The ratio of the average reflectance over the 500-600 nm wavelength range to the average reflectance over the 600-650 nm wavelength range was 1:0.63. Since the ratio of the average reflectance over the 600-650 nm wavelength range to the average reflectance over the 500-600 nm wavelength range is between 0.6 and 0.8, it is presumed that the leaves of the target plant were bright, and even in the young leaf stage, they were able to promote a visual confusion effect on pests, leading to a pest suppression effect. The reflectance peaked in the 500-600 nm wavelength range (31.9%), and the average reflectance over the 500-600 nm wavelength range (A) was 29.5%, the average reflectance over the 300-400 nm wavelength range (B) was 8.2%, and the average reflectance over the 600-650 nm wavelength range (C) was 18.7%, satisfying the relationship (1) (A)>(C)>(B).

[0082] [Example 3] As a biodegradable resin, 95.8 parts by weight of aliphatic aromatic polyester and 4.2 parts by weight of aliphatic polyester resin were mixed to a total of 100 parts by weight, and various pigments and additives were added in the amounts shown in Table 1. A film was then formed using the film formation method described above. The obtained film was stretched and evaluated according to (a) to (f) above. In the measurement wavelength range of 300-650 nm, the peak in the 500-600 nm wavelength range was around 517 nm, and the average reflectance across the 500-600 nm wavelength range was 19.3%. On cabbage leaves, there were 132 cabbage white butterflies, 276 moth parasites, 6 diamondback moth parasites, and 84 aphid parasites. On radish leaves, there were 6 cabbage white butterflies and 7 moth parasites. The sample exhibited a peak value in the 500-600nm wavelength range, and its average reflectance across this range was between 10% and 50%, closely matching the reflectivity characteristics of the target plant's leaves. This confirmed its pest-suppressing effect. Because the average reflectance across the 500-600nm wavelength range is relatively low at 19.3%, it was confirmed to be particularly effective against nocturnal pests such as moths. The average reflectance over the 300-400nm wavelength range was 7.5%, and since the average reflectance is less than 15%, it is presumed that this suppressed the retention of pests on the film, leading to the pest control effect. The average reflectance over the 600-650nm wavelength range was 13.7%, and since the average reflectance is between 5% and 40%, it is presumed that the leaves of the target plant, such as cabbage, were bright, and even in the young leaf stage, the light was able to confuse the eyes of pests, leading to a pest control effect. The ratio of the average reflectance over the 500-600 nm wavelength range to the average reflectance over the 600-650 nm wavelength range was 1:0.75. Since the ratio of the average reflectance over the 600-650 nm wavelength range to the average reflectance over the 500-600 nm wavelength range is between 0.6 and 0.8, it is presumed that the leaves of the target plant were bright, and even in the young leaf stage, they were able to promote a visual confusion effect on pests, leading to a pest suppression effect. The reflectance peaked in the 500-600 nm wavelength range (19.3%), and the average reflectance over the 500-600 nm wavelength range (A) was 18.3%, the average reflectance over the 300-400 nm wavelength range (B) was 7.5%, and the average reflectance over the 600-650 nm wavelength range (C) was 13.7%, satisfying the relationship (1) (A)>(C)>(B).

[0083] [Comparative Example 1] A commercially available black and white two-layer film (manufactured by Tokan Kogyo Co., Ltd., product name "Black and White Multi Black & White") was stretched out and the evaluations described in (a) to (f) above were performed. In the measurement wavelength range of 300-650 nm, no peak was observed in the 500-600 nm wavelength range, and the average reflectance across the 500-600 nm wavelength range was 57.0%. On cabbage leaves, there were 136 cabbage white butterflies, 563 loopers, 34 diamondback moths, and 258 aphids. On radish leaves, there were 7 cabbage white butterflies and 32 loopers. The material did not exhibit a peak value in the 500-600 nm wavelength range, and its average reflectance across this range exceeded 50%. As a result, it was found to have a low effect in suppressing egg-laying against all pests, and was particularly ineffective against nocturnal moth pests such as locusts. The average reflectance over the wavelength range of 300-400 nm was 10.3%, and the average reflectance was less than 15%. The average reflectance over the 600-650nm wavelength range was 51.9%, which is higher than 40%. This suggests that the leaves of the target plant, such as cabbage, were not able to fully exert their visual confusion effect on pests during the bright, young leaf stage, resulting in a low pest control effect. The ratio of the average reflectance over the 500-600 nm wavelength range to the average reflectance over the 600-650 nm wavelength range was 1:0.91. The ratio of the average reflectance over the 600-650 nm wavelength range to the average reflectance over the 500-600 nm wavelength range was greater than 0.8, indicating that the film appeared somewhat yellowish, resembling old leaves. It is presumed that the film was unable to adequately disrupt the visual perception of pests during the bright, young leaf stage of the target plant, such as cabbage, resulting in a low pest control effect. No reflectance peak was observed in the 500-600 nm wavelength range.

[0084] [Comparative Example 2] A commercially available black film (manufactured by Mitsubishi Chemical Agri-Dream Co., Ltd., product name "Kaeruuchi") was stretched out and the evaluations described in (a) to (f) above were performed. In the measurement wavelength range of 300-650 nm, no peak was observed in the 500-600 nm wavelength range, and the average reflectance across the 500-600 nm wavelength range was 4.6%. On cabbage leaves, there were 155 cabbage white butterflies, 373 moth parasites, 8 diamondback moth parasites, and 41 aphid parasites. On radish leaves, there were 10 cabbage white butterflies and 7 moth parasites. The product did not exhibit a peak value in the 500-600 nm wavelength range, and its average reflectance across this range was less than 10%. This indicated a low inhibitory effect on cabbage white butterfly and moth parasites on cabbage, and on cabbage white butterfly parasites on radishes. In particular, it was confirmed to be ineffective against diurnal cabbage white butterfly pests. The average reflectance over the 300-400nm wavelength range was 5.4%, which is below 15%. However, the average reflectance over the 600-650nm wavelength range was 4.5%, which is lower than 5%. This suggests that the leaves of the target plant, such as cabbage, were not bright enough, and the visual confusion effect on pests was not fully realized during the young leaf stage, resulting in a low pest control effect. The ratio of the average reflectance over the 500-600 nm wavelength range to the average reflectance over the 600-650 nm wavelength range was 1:0.98. The ratio of the average reflectance over the 600-650 nm wavelength range to the average reflectance over the 500-600 nm wavelength range was greater than 0.8, indicating that the film appeared somewhat yellowish and resembled old leaves. It is presumed that the film was unable to adequately disrupt the visual perception of pests during the bright, young leaf stage of the target plant, such as cabbage, resulting in a low pest control effect. No reflectance peak was observed in the 500-600nm wavelength range. Furthermore, the average reflectance (A) over the 500-600nm wavelength range was 4.6%, the average reflectance (B) over the 300-400nm wavelength range was 5.4%, and the average reflectance (C) over the 600-650nm wavelength range was 4.5%, thus failing to satisfy the relationship (1) (A)>(C)>(B).

[0085] [Reference example 1] The reflectance of a commercially available dark green film (manufactured by Sumika Sekisui Film Co., Ltd., product name "Dark Green Multi") was measured as described above. In the measurement wavelength range of 300-650 nm, no peak was observed in the 500-600 nm wavelength range, and the average reflectance across the 500-600 nm wavelength range was 4.0%. Although the pest-suppressing effect has not been confirmed, it is presumed to have a low pest-suppressing effect because its reflective properties are similar to those of Comparative Example 2.

[0086] [Reference example 2] The reflectance of a commercially available dark green film (manufactured by Okura Industries Co., Ltd., product name "Dark Green Multi") was measured as described above. In the measurement wavelength range of 300-650 nm, no peak was observed in the 500-600 nm wavelength range, and the average reflectance across the 500-600 nm wavelength range was 4.4%. Although the pest-suppressing effect has not been confirmed, it is presumed to have a low pest-suppressing effect because its reflective properties are similar to those of Comparative Example 2.

[0087] [Reference example 3] The reflectance of a commercially available light green film (manufactured by Okura Industries Co., Ltd., product name "Light Green Multi") was measured as described above. In the measurement wavelength range of 300-650 nm, no peak was observed in the 500-600 nm wavelength range, and the average reflectance across the 500-600 nm wavelength range was 5.0%. Although the pest-suppressing effect has not been confirmed, it is presumed to have a low pest-suppressing effect because its reflective properties are similar to those of Comparative Example 2.

[0088] [Reference example 4] The reflectivity of cabbage leaves was measured as described above.

[0089] Table 1 shows the results of reflectance measurements in each wavelength range and confirmation of the pest suppression effect of the obtained film, using the test method described above.

[0090] [Table 1]

[0091] [Example 4] A film similar to that in Example 1 was stretched, and evaluations (g) and (h) described above were performed. The number of cabbage leaves infested with cabbage white butterflies was 126, and the number of aphids infested with cabbage leaves was 63. The optical properties were the same as those in Example 1.

[0092] [Example 5] As the polyethylene resin, 85.2 parts by weight of polyethylene resin and 14.8 parts by weight of biodegradable resin containing additives and pigments were mixed to a total of 100 parts by weight. Various pigments and additives were added in the amounts shown in Table 2, and a film was formed using the film formation method described above. The obtained film was stretched and evaluated according to (g) and (h) above. The number of cabbage white butterfly infestations on a cabbage leaf was 123, and the number of aphid infestations was 167. The sample exhibited a peak value in the 500-600nm wavelength range, and its average reflectance across this range was between 10% and 50%, closely matching the reflectivity characteristics of the target plant's leaves. This confirmed its pest-suppressing effect. Since the average reflectance across the 500-600nm wavelength range is an intermediate 29.9%, it was confirmed to be effective against cabbage white butterflies and aphids. The average reflectance over the 300-400nm wavelength range was 7.3%, and since the average reflectance is less than 15%, it is presumed that this suppressed the retention of pests on the film, leading to a pest control effect. The average reflectance over the 600-650nm wavelength range was 21.2%, and since the average reflectance is between 5% and 40%, it is presumed that the leaves of the target plant, such as cabbage, were bright, and even in the young leaf stage, the light was able to confuse the eyes of pests, leading to a pest control effect. The ratio of the average reflectance over the 500-600 nm wavelength range to the average reflectance over the 600-650 nm wavelength range was 1:0.71. Since the ratio of the average reflectance over the 600-650 nm wavelength range to the average reflectance over the 500-600 nm wavelength range is between 0.6 and 0.8, it is presumed that the leaves of the target plant were bright, and even in the young leaf stage, they were able to promote a visual confusion effect on pests, leading to a pest suppression effect. The reflectance peaked in the 500-600 nm wavelength range (32.1%), and the average reflectance over the 500-600 nm wavelength range (A) was 29.9%, the average reflectance over the 300-400 nm wavelength range (B) was 7.3%, and the average reflectance over the 600-650 nm wavelength range (C) was 21.2%, satisfying the relationship (1) (A)>(C)>(B). In Example 5, the main component resin was polyethylene resin, and it was confirmed that pest control effects can be obtained if the optical properties are satisfied.

[0093] [Comparative Example 3] A film similar to that in Comparative Example 2 was unfolded, and evaluations (g) and (h) described above were performed. The number of cabbage white butterfly infestations on a cabbage leaf was 367, and the number of aphid infestations was 685. The optical properties were similar to those of Comparative Example 2.

[0094] The obtained films were subjected to the above test method, and the reflectance measurement results in each wavelength range, as well as the results of confirming the pest suppression effect, are shown in Table 2.

[0095] [Table 2] [Industrial applicability]

[0096] The present invention provides an agricultural film with pest control effects. Since the agricultural film of the present invention does not contain pest repellents like those in the prior art, it avoids the problem of reduced pest control effectiveness due to repellent bleed-out, thus maintaining pest control effectiveness throughout its lifespan as a general agricultural film. Furthermore, because the agricultural film of the present invention has excellent pest control effects, it is possible to reduce the amount of pesticides used, thus providing an environmentally friendly cultivation technique.

Claims

1. In the measurement wavelength range of 300 to 650 nm, It has a reflectance peak in the wavelength region of 500 to 600 nm, The average reflectance over the wavelength range of 500 to 600 nm is 10% or more and 50% or less. Agricultural film.

2. 2. The agricultural film according to claim 1, wherein the average reflectance over the wavelength region of 300 to 400 nm is 15% or less.

3. 2. The agricultural film according to claim 1, wherein the average reflectance over the wavelength region of 600 to 650 nm is 5% or more and 40% or less.

4. 4. The agricultural film according to claim 3, wherein the ratio of the average reflectance over the wavelength region of 500 to 600 nm to the average reflectance over the wavelength region of 600 to 650 nm is in the range of 1:0.6 to 1:0.

8.

5. In the measurement wavelength range of 300 to 650 nm, It has a reflectance peak in the wavelength region of 500 to 600 nm, Agricultural film that satisfies the following conditions: (A)>(C)>(B)...Formula (1) (A): Average reflectance over the wavelength range of 500 to 600 nm (B): Average reflectance over the wavelength range of 300 to 400 nm (C): Average reflectance over the wavelength range of 600 to 650 nm

6. An agricultural pest control film using the agricultural film according to any one of claims 1 to 5.

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