JPH0638635A - Wave length changing material - Google Patents

Abstract

PURPOSE:To obtain a wavelength changing material capable of harvesting in a high yield and in a short period in the case of a vegetable, etc., and of harvesting high- quality fruits in the case of a fruit by using respectively specified two kinds of fluorescent pigments selected so that the emission spectrum of one of the above mentioned pigments and the absorption spectrum of the other pigment may partly overlap each other. CONSTITUTION:The material contains (A) a fluorescent pigment (e.g. PTP or BPA) having the absorption maximum at 350 to 450nm and the emission maximum at 380 to 520nm and (B) another fluorescent pigment (e.g. lumogen F Red 300 or luminol Red Violet 635P) having the absorption maximum at 460 to 580nm and the emission maximum at 540 to 800nm. The above-mentioned two pigments are selected so that the emission spectrum of the component (A) and the absorption spectrum of the component (B) may partly overlap each other. The ratio of the emission strength of the component (A) to the strength of emission generated by a part of the excitation energy of the component (A) at the position of emission of the component (B) is 0.2 to 5. The Stokes' shift of the components (A) and (B) is >=20nm and the absorbance values of the fluorescent pigments at each absorption maximum wavelength of the components (A) and (B) are <=1.3.

Description

Detailed Description of the Invention

[0001]

BACKGROUND OF THE INVENTION 1. Field of the Invention The present invention relates to a wavelength conversion material for agriculture having a function of converting the light spectrum of sunlight and artificial light sources used in plant factories into light effective for promoting plant growth.

[0002]

2. Description of the Related Art In recent years, institutional horticulture for cultivating useful plants in greenhouses or tunnels has become widespread, and compared to open-field cultivation, the yield and quality are dramatically improved, which is important for a stable supply of vegetables and fruits. Is playing a different role.
The greatest significance of institutional cultivation is to keep the heat inside the house and tunnel, and to protect the plants from damages such as rain, wind, insects, etc. Therefore, for vegetables, seasonal cultivation to year-round cultivation, pear, Fruit trees such as mandarin oranges, grapes, oysters, and apples are beginning to be harvested in good shape with high sugar content. On the other hand, after gardening became widely practiced,
Attempts to increase the yield and to improve the quality of sunlight, and to convert the spectrum of sunlight into an advantageous form for photosynthesis of plants or production of growth active materials, that is, to a synthetic resin film used for institutional horticulture. By dissolving a fluorescent compound that has a wavelength conversion function, it absorbs near-ultraviolet light, which is harmful to plants in some cases, and converts it into blue light that is useful for photosynthesis, or green with low photosynthetic efficiency. -Many attempts have been made to convert yellowish light into orange-redish light having a longer wavelength.

For example, a research result report of the research corporation "Agricultural light ray selective utilization technology research association" (Showa 39-57) "Comprehensive research on technicalization of utilization of light quality in facility agriculture"
(February 1976, Secretariat of the Agriculture, Forestry and Fisheries Technology Council) made a trial film of a blue fluorescent substance, a red fluorescent substance, and a film in which they were simultaneously dissolved in vinyl chloride, but the light resistance was poor and a cultivation test was conducted. It has been reported that it was suspended without it. JP-B-49-16301, JP-A-52-94345,
JP-A-2-102265, JP-A-2-147651, JP-A-3-2110
In 53, fluorescent brighteners, scintillators, etc. are proposed as dyes for converting near-ultraviolet light into photosynthetic effective light, but their light resistance is insufficient and they have not been put to practical use for institutional horticulture. Japanese Unexamined Patent Publication (Kokai) No. 54-127945 discloses a film for converting green to yellow light into orange to red light by using Rhodamine 6G. However, this dye also has poor light resistance and is left as it is unless proper light stabilization treatment is carried out. It cannot be put to practical use.

JP-A-57-189 discloses polymers such as polyesters, polyamides, polycarbonates, polyacrylates, polystyrenes and polysulfones having solubility parameters of 9 or more, anthraquinone type phosphors, thioindigo type phosphors, perinone type phosphors, A wavelength-convertable molded body in which a plurality of organic phosphors selected from perylene-based phosphors and the like are dissolved is disclosed. The plurality of organic phosphors absorbs light on the short wavelength side so as to transfer energy from the first phosphor excited to the second phosphor having a smaller excitation energy in a non-radiative manner, that is, the first phosphor. Since the emission spectrum of the fluorescent substance and the absorption spectrum of the second fluorescent substance are combined so as to partially overlap each other, it is possible to convert light in the short wavelength side of a wide range into light in the longer wavelength side. A certain effect on plant cultivation can be expected. However, the idea of the present invention considers only red light as effective light for plant cultivation, and does not consider the wavelength region of light on the short wavelength side to be converted, and the chlorophyll a, b, and carotene of blue light are used. It also has a negative effect of inhibiting the action.

Radiant pink (trade name; Mitsui Toatsu Chemicals, Inc.), which is a red light emitting film, Irradiant 66
0 (Brand name; BASF) was put on the market and cultivation tests were conducted, but these wavelength conversion films that convert light in a single wavelength region are generally not sufficiently effective and effective under specific weather conditions. However, there were many cases where the effect was not seen under other weather conditions, and it was unreliable to use as a practical material for gardening.

[0006]

SUMMARY OF THE INVENTION The present invention provides an agricultural wavelength conversion material for promoting the growth of crops by converting the spectrum of sunlight or light of an artificial light source in facility cultivation of useful crops under such circumstances. The purpose is to do. Photoreceptors that control the growth of crops mainly include chlorophyll a, b, phytochrome type I, type II, type III, and a blue light-receiving pigment that is said to be acted on by flavin pigments, carotenoids, or both. It has been known. Phytochrome type I, type II, type III,
The function of blue light-receptive dyes has been studied variously (for example, "Light Application Technology in Agriculture" Vol. 44, No. 4, page 406, Applied Physics (1975) and "Phytochrome and Gibberellin" vol.24, No. .2, 105, phytochrome is used for chemical regulation of plants (1989), etc.
Pfr type, which has two absorption types and acts to promote plant growth in the photomorphogenic reaction, mutually emits light by Pr type and r light (light centered at 670 nm) and fr light (light centered at 725 nm). It is described to convert. ), It has not yet been fully elucidated, and it is not possible at present to predict what kind of light spectrum should be given to crops.

In the present invention, a part of near-ultraviolet light to blue light in a specific region of the light spectrum of sunlight and artificial light sources used in plant factories is converted into blue light and orange to red light, and at the same time green light is emitted. Part of the light in the center area is orange at a specific ratio
The light spectrum converted by wavelength conversion into red light is chlorophyll a, b; phytochrome I type, II type,
It has been found that it effectively acts on type III, blue light-receptive pigments, etc., thereby increasing the yield and improving the quality of crops.

[0008]

The gist of the present invention is that the light spectrum is such that it acts on chlorophyll, phytochrome, blue light-receptive dyes, etc., and effectively acts on photosynthesis, photomorphogenesis, photoperiodicity, etc. Specifically, the absorption maximum is 350 to 450 nm, preferably 370 to 430 nm, and the emission maximum is 380 to 520 nm, preferably 400 to 460 nm.
nm has at least one fluorescent dye (A) and absorption maximum of 46
It contains at least one fluorescent dye (B) having an emission maximum at 540 to 800 nm, preferably 570 to 700 nm, at 0 to 580 nm, preferably 480 to 550 nm, and (A) The combination is such that the emission spectrum and the absorption spectrum of (B) partially overlap, and the emission intensity (I) of (A) and part of the excitation energy of (A) are at the emission position of (B). The wavelength conversion material for agriculture is characterized in that the ratio (I) / (I ′) of emitted light intensity (I ′) is 0.2 or more and 5 or less. The conversion function of the wavelength conversion material for agriculture of the present invention will be described in more detail. The fluorescent dye (A) mainly emits near-ultraviolet light in part to blue light and part in orange to red due to energy transfer through the fluorescent dye (B). As a result of conversion into light and the fluorescent dye (B) converting light in the green light region into orange to red light, the light spectrum applied to the wavelength conversion material of the present invention is dimmed in the near ultraviolet light region and the green light region. The blue light region and the orange to red light region are transmitted with the increased spectrum. The light in the blue light region does not interfere with the actions of chlorophyll a, b, and carotene that utilize blue light existing in plants, in order to prevent the action of the emission intensity (I) of (A) and the excitation energy of (A). It is preferable that the ratio (I) / (I ′) of the intensity (I ′) of which part of the light is emitted at the emission position of (B) is 0.2 or more and 5 or less, preferably 0.4 or more and 3 or less.

If the Stokes shift (difference between the absorption maximum wavelength and the emission maximum wavelength) of the fluorescent dye (A) and the fluorescent dye (B) is not large to some extent, the efficiency of wavelength conversion for plant growth decreases, and at least 20 nm or more. Is more effective, and it is particularly preferable that the Stokes shift of the fluorescent dye (B) is larger. When it is 20 nm or less, even if wavelength conversion is performed, it rarely exerts an accelerating effect on plant growth.

The fluorescent dye (A) is, for example, polyphenyl type such as PTP, anthracene and 9,10-diphenylanthracene, stilbene type such as BPA, DPS, stilbene 1 and stilbene 3 and styryl such as 1,4-distyrylbenzene. Benzene-based, popop, Dimethylpopop, P
Oxazoles such as BO, Oxadiazoles such as PBD, Coumarin 4,151,307,311, DMA
C, coumarin type, Mica White ATN, 4-aminonaphthalic acid phenylimide, naphthalimide type, CI
Vat Blue 19, 20, 22 and other anthraquinone series, Luminol Red Violet 440PT, 1,5-diphenyl-3-styryl-2-pyrazoline and other pyrazoline series 2,5-
Examples thereof include dihydroxy terephthalate compounds such as ethyl dihydroxy-terephthalate and ethyl 2,5-dihydroxy-4-methoxycarbonylbenzoate, and cyanopyrazine derivatives described in Japanese Patent Application Nos. 3-242321 and 4-301673.

The fluorescent dye (B) is, for example, Lumogen F Red 30.
Perylene series such as 0, anthraquinone series such as Luminol Red Violet 635P, thioindigo series such as thioindigo Bright Pink G, thioindigo Scarlet R, Luminol Bright Orange 575PT,

[0012]

[Chemical 1] Naphthalic acid type such as, xanthene type such as Rhodamine, Acridine Red,

[0013]

[Chemical 2] Coumarin type,

[0014]

[Chemical 3] Such as naphtholine,

Examples include cyanopyrazine derivatives described in Japanese Patent Application No. 3-242321 and Japanese Patent Application No. 4-301673, and benzopteridine derivatives described in Japanese Patent Application No. 4-89563.
Among these, Lumogen F Red 300, Japanese Patent Application No. 3-242321
Also, the cyanopyrazine derivative described in Japanese Patent Application No. 4-301673 and the benzopteridine derivative described in Japanese Patent Application No. 4-89563 are preferable examples because they have a Stokes shift of 40 or more in the resin. The cyanopyrazine derivatives described in Japanese Patent Application Nos. 3-242321 and 4-301673 and the benzopteridine derivatives described in Japanese Patent Application No. 4-89563 have a Stokes shift of 50 or more and are particularly preferable. Generally, in a system like the present invention, a fluorescent dye 1 that absorbs short wavelength light and a fluorescent dye 2 that absorbs long wavelength light are mixed and dissolved, and the emission spectrum of 1 and the absorption spectrum of 2 partially overlap. It is known that the photostability of the fluorescent dye 1 is remarkably improved. Therefore, the fluorescent dye (A) of the present invention can also be used as an unstable dye which cannot be used alone. On the other hand, the fluorescent dye (B) itself is photostable, or has stability such that it is stabilized by an ultraviolet absorber, an antioxidant, an additive such as a singlet oxygen quencher, and other photostabilization treatment. Must be one.

Specifically, the wavelength conversion film of the present invention is installed inside a UV cut film that absorbs near-ultraviolet light having a wavelength of 400 nm or less, and the fluorescent dye (A) and the fluorescent dye after irradiation with sunlight for 1 year The retention rate of the emission intensity of (B) is preferably at least 50%. If the retention rate is lower than this, it is difficult to bring out the wavelength conversion effect with good reproducibility.

Materials used in the present invention include, for example,
It is a board, a net, a woven cloth, a non-woven cloth, etc., and those materials are, for example, (soft, semi-rigid, hard) PVC; polyethylene; polypropylene; polyvinyl alcohol; polyvinyl acrylate; polyvinyl methacrylate; polyvinylidene chloride; polyacrylonitrile; polybutadiene. ;
Polystyrene; ethylene-vinyl acetate copolymer; vinyl chloride-vinyl acetate copolymer; polyvinyl butyral; polyvinyl formal; polyesters such as PET and PBT; polyarylate; polycarbonate; polyester carbonate; phenoxy resin; nylon 6, nylon 6/6 Polyamide, nylon 11, nylon 12, MXD6 nylon, etc .; polydimethylsiloxane; polytrimethylsilylpropyne; polyurethane; ionomers; cellophane; polyethylene cellophane; cellulose acetate; cellulose propionate; ethyl cellulose; nitrocellulose and other soft and hard resins Etc. The method for producing the wavelength conversion material is not particularly limited, and it is produced by extrusion molding, inflation molding, calender molding, or the like depending on the melting characteristics of the resin, solvent solubility, thermal characteristics of the fluorescent dye, or a resin-dissolved varnish. It can be produced by coating glass, a plastic plate, a reflector, a film or the like or impregnating woven cloth, non-woven cloth, paper or the like. The thickness of the resin layer containing the fluorescent dyes (A) and (B) is 10 to 300 μm, preferably 30 to 150 μm for both the molding film and the coating layer.

The concentration of the fluorescent dyes (A) and (B) contained in the resin is 0.01 to 2.0%, preferably 0.05 to 0.5%. If the concentration is lower than 0.01%, the wavelength conversion function is not sufficient, and if the concentration is higher than 2.0%, the absorption rate of light is large and the effect of concentration quenching, which is a characteristic of fluorescent compounds, is exhibited and the wavelength conversion efficiency decreases. . Further, the absorbance of the fluorescent dye at the absorption maximum wavelength of the fluorescent dye (A) and the fluorescent dye (B) is preferably 1.3 or less, and when it is larger than this, the light absorption ratio and the absorption wavelength region are too large, resulting in a light shielding effect. Is strongly displayed, which is not preferable. A type and amount of an ultraviolet absorber, an antioxidant, a singlet oxygen quencher, a hindered amine-based light stabilizer, and other stabilizers that do not impair the object of the present invention for satisfying other various conditions as a facility gardening material, You may mix | blend additives, such as a lubricant, an antifogging agent, and a drip agent.

The wavelength conversion material containing the fluorescent dyes (A) and (B) depends on the refractive index of the resin, but 60 to 80% of the emitted light is totally reflected at the interface with the air and propagates through the film. go. In many cases, the trapped light has an absorption spectrum that overlaps with an emission spectrum, so that part of the light is repeatedly absorbed and emitted again. At this time, since the light emission is performed by the amount obtained by multiplying a certain conversion efficiency, the energy loss becomes a size that cannot be ignored. Inorganic fine powder such as silica, alumina, or plastic fine powder is blended so that the emitted light can be effectively emitted from the inner surface of the film while avoiding such energy loss, or the inner surface of the film is regularly or It is preferable to perform a roughening process for providing irregular irregularities. The roughening can be performed by a commonly used method such as wire brush, sand blasting or embossing. The material having the wavelength conversion function of the present invention is not only a covering material for a vinyl house but also a multi-film, a reflective (multi) film, a reflector plate installed so that sunlight is evenly irradiated in the house, a plastic net, a woven cloth. It is also used for non-woven fabrics and bags for hanging fruits.

An additional effect of the present invention is the control effect of harmful insects by red light. As a method for controlling insect pests by light, a method of covering the soil with a highly reflective film as disclosed in JP-A-52-61581 and a method for absorbing green light as disclosed in JP-B-2-58898. A typical example is a mulch film containing a red pigment that reflects red light, but these cannot be used as a film for spreading in houses, tunnels, etc. due to their low light transmittance. The wavelength conversion material of the present invention has fluorescent dyes (A) and (B) in the resin.
Since the incident light is not scattered, it is efficiently transmitted or is converted into blue light and orange to red light and emitted, but orange to red light emits beetles, aphids and whiteflies. Pests such as species have the action of repelling them, and therefore the use of pesticides in houses and tunnels can be greatly reduced.

[0021]

The present invention will be described in detail below with reference to examples. In the examples, "part" represents part by weight. The fluorescence spectrum was measured using a Fluorescence Spectrophotometer 850 manufactured by Hitachi, Ltd. Transmittance is spectrophotometer UV-2 made by Shimadzu Corporation
It was measured using 40.

Example 1 (Production of film) Varnish (varnish a) obtained by dissolving 100 parts of polycarbonate resin (CALIBRE 300-6: Sumitomo Nogatac Co., Ltd.) in 667 parts of methylene chloride, CALIBRE 300-6; 100 parts, CALIB, a varnish prepared by dissolving 2.0 parts of UV absorber (Biosorb 910: Kyodo Pharmaceutical Co., Ltd.) in 667 parts of methylene chloride
RE 300-6; 100 parts, Biosorb 910; 2.0 parts, cyanopyrazine derivatives of the following formulas [I] and [II] described in Japanese Patent Application No. 3-242321

[0023]

[Chemical 4]

[0024]

[Chemical 5]

A varnish (Varnish C) prepared by dissolving 0.2 parts of each in 667 parts of methylene chloride was prepared, and a polyethylene terephthalate film (SG-2, film thickness 75 μm, Teijin Ltd.) subjected to a primer treatment was reverse roll coated. Coating and drying using each, dry film thickness of about 4
0 μm (including the base film thickness of about 115 μm) 3
Various types of films a, b, and C (in which the fluorescent dyes (A) and (B) were dissolved) were manufactured. Figure 2 shows the transmittance of the film
The fluorescence excitation and emission spectra are shown in FIG.
From FIG. 3, the ratio of the emission intensity of this film C (I) /
It can be seen that (I ') is about 0.5.

Example 2 (Production of film) 100 parts of polypropylene (Mitsui Noblene BJ4H-G: Mitsui Toatsu Chemical Co., Ltd.), 0.2 part of the cyanopyrazine derivative [I] used in Example 1 and cyanopyrazine derivative [I]
I] 0.2 parts, UV absorber Biosorb 910; 2.0 parts 2
After kneading with a heat roll set at 10 ° C for 3 minutes,
Thickness is 0.15 after press molding with a 70t hot press at 210 ° C.
mm film was made. The excitation and emission spectra of the film were measured and found to be 4
It has emission peaks at 66 nm and 592 nm, 472
When excited with nm light, it showed emission with a maximum at 592 nm.

Example 3 (Lightfastness of Film) The film C produced in Example 1 was used from October 18, 1989 to 19
As a result of natural exposure for 1 year until October 19, 1990, the retention rate of the emission intensity at 452 nm of the dye [I] excited by 397 nm light was 66%, and the dye excited by 492 nm light was The retention rate of the emission intensity of [ΙΙ] at 590 nm was 68%.

Example 4 The varnish-coated side of the film produced in Example 1 was coated with No.
After roughening with 80 sandpaper, small houses of about 10 m ² each were assembled with this surface inside. Heisei 3
Seedlings of cucumber (Tenma) and lettuce (Sacramento) seeded on May 13, 2013 (medium: WEDGE OASIS 5631; Nippon Soda Co., Ltd.) in a pot (5 l of Inawashiro Hayama soil, 5 ripe compost)
Soil mixed with 1 g, 7 g of dicyan (Showa Denko KK) and 51 g of gemstone was used. )) (June 7th)
On October 11, 10 pots each of cucumber and lettuce were moved to each house to start the experiment. For irrigation, an automatic irrigation device was set, and irrigation was performed once a day at about 9:00 at 500 to 600 ml / pot (1000 ml / pot since July 23). Fertilization was performed at appropriate intervals using OASIS liquid fertilizer (Nippon Soda Co., Ltd.), Fuchin Gold (Nippon Soda Co., Ltd.), or the like. No pesticides were used. The test was conducted until August 21, and the harvest weight of cucumber and lettuce was recorded. The results are shown in Table-1 and Table-2.

[0029]

[Table 1]

[0030]

[Table 2]

Example 5 (Production of Reflective Film) Instead of polyethylene terephthalate, a reflective film (polyethylene film: silver polytow N, 0.10 m)
The reflective films a ′, b ′, and C ′ were manufactured in the same manner as in Example 1 by using m. Tokan Kogyo Co., Ltd.

Example 6 The coated surface of the reflective film produced in Example 5 was No. 80
After roughening with sandpaper, the reflective mulch film was spread in the north and south with this side facing up. Tomato seedlings (cultivar: Saturn) sown (medium: WEDGE OASIS 5631; Nippon Soda Co., Ltd.) on June 13, 1991 were placed on the reflective mulch film on July 4 at 15 cm intervals at 30 cm intervals.
It was transplanted to a row and the test was started. Harvesting was performed up to the fourth fruit cluster. The test results are shown in Table-3.

[0033]

[Table 3]

Example 7 (Production of film) Cyanopyrazine derivative [II] (fluorescent dye (B))
Lumogen F Red 300 (BASF Japan Ltd.
) (Fluorescent dye (B)) 0.1 part except that Example 1 is used.
The varnish D was prepared in the same manner as the varnish C in Example 1, and the film D (fluorescent dyes (A) and (B) was prepared in the same manner as in Example 1.
Are dissolved). The transmittance of the film is shown in FIG. 4, and the fluorescence excitation and emission spectra are shown in FIG. From FIG. 5, the ratio of the emission intensity of this film D (I) /
It can be seen that (I ') is about 1.6.

Example 8 The side of the films b and C produced in Example 1 on which the varnish was applied was No. After roughening with 80 sandpaper, small houses of about 10 m ² each were assembled with this surface inside. A similar small house was assembled using a 0.1 mm thick ultraviolet ray-cutting agricultural product (trade name: Cut Ace: Mitsubishi Kasei Vinyl). Seeding on April 1, 1992 (medium: WE
DGE OASIS 5631; Nippon Soda Co., Ltd. tomato (Momotaro) seedlings in pots (Inawashiro Hayama soil 5 liters,
Soil mixed with 5 l of fully-ripened compost, 7 g of dicyan (Showa Denko KK), and 51 g of gemstone was used. ) Transplant (May 1)
Then, on May 23, 10 pots were moved to each house to start the experiment. For irrigation, set an automatic irrigation device,
Irrigation was performed once a day at about 9:00 at 500 to 600 ml / pot. The fertilization was performed at appropriate intervals using OASIS liquid fertilizer (Nippon Soda Co., Ltd.), Fuchin Gold (Nippon Soda Co., Ltd.) or the like. No pesticides were used. The test was conducted until September 26, and the harvest weight and the like were recorded. The results are shown in Table-4.

[0036]

[Table 4]

[0037]

The present invention has the following effects and its practical utility is extremely large. (1) The wavelength conversion material for agriculture of the present invention uses sunlight and light in the near-ultraviolet light region and green light region of the artificial light source used in plant factories, etc., which are effective for plant growth in the blue light region and orange light. ~ It can be converted into light in the red light region. (2) By growing fruit trees such as vegetables, flowers, pears, mandarins, grapes, oysters, apples, etc. in a house using the wavelength conversion material of the present invention, in the case of vegetables and flowers, high yield, fruit trees In this case, high quality fruits can be harvested, for example, by controlling the fruit color, increasing the sugar content, and increasing the fruit size. (3) Pests can be controlled by the orange to red light emitted by the wavelength conversion material of the present invention.

[Brief description of drawings]

FIG. 1 shows mutual light conversion of r light and fr light.

2 is a spectral transmittance of the films a, b, and C obtained in Example 1. FIG.

FIG. 3 is an excitation and emission spectrum of the film C obtained in Example 1. (P) is the excitation spectrum for the 452 nm emission of the fluorescent dye (A). (Q) is the emission spectrum of the fluorescent dye (A) upon excitation at 397 nm. (I) is the emission peak of the fluorescent dye (A) itself. (I ′) is a peak that emits light as a result of energy transfer of the excitation energy of the fluorescent dye (A) to the fluorescent dye (B). (R) is the excitation spectrum for the 590 nm emission of the fluorescent dye (B). (S) is the emission spectrum of the fluorescent dye (B) upon excitation at 492 nm.

4 is a spectral transmittance of the film D obtained in Example 7 and the films a and b obtained in Example 1. FIG.

5 is an excitation and emission spectrum of the film D obtained in Example 7. FIG. (P ') is the excitation spectrum for the 462 nm emission of the fluorescent dye (A). (Q ') is the emission spectrum of the fluorescent dye (A) upon excitation at 397 nm. (I) is the emission peak of the fluorescent dye (A) itself. (I ′) is a peak that emits light as a result of energy transfer of the excitation energy of the fluorescent dye (A) to the fluorescent dye (B). (R ') is the excitation spectrum for the 610 nm emission of the fluorescent dye (B). (S ') is the emission spectrum of the fluorescent dye (B) upon excitation at 570 nm.

 ─────────────────────────────────────────────────── ─── Continuation of the front page (72) Inventor Takeshi Gumihara 3967 Hikka Amadayama, Sarashina, Bandai-cho, Yama-gun, Fukushima Prefecture On the Bandai Farm of Nippon Soda Co., Ltd.

Claims (3)

[Claims] 1. At least one fluorescent dye (A) having an absorption maximum at 350-450 nm and an emission maximum at 380-520 nm.
And the absorption maximum at 460 to 580 nm, and the emission maximum at 540 to 80
At least one fluorescent dye (B) at 0 nm is contained in the combination such that the emission spectrum of (A) and the absorption spectrum of (B) partially overlap, (A)
Ratio (I) / intensity (I) of (A) and intensity (I ′) at which a part of the excitation energy of (A) emits light at the emission position of (B)
(I ') is 0.2 or more and 5 or less, The wavelength conversion material for agriculture characterized by the above-mentioned. 2. The agricultural wavelength conversion material according to claim 1, wherein the Stokes shift of at least one fluorescent dye (A) and at least one fluorescent dye (B) is 20 nm or more. 3. The wavelength conversion material for agriculture according to claim 1, wherein the absorbance of the fluorescent dye at the absorption maximum wavelength of at least one fluorescent dye (A) and at least one fluorescent dye (B) is 1.3 or less.