JP2021058114A - Method for producing crops and semiconductor light-emitting device - Google Patents

Abstract

To provide a method for producing crops that can produce delicious crops and a semiconductor light-emitting device.SOLUTION: A method for producing crops irradiates crops with light emitted by a semiconductor light-emitting device 100. The intensity of light with a wavelength of 430 nm in the semiconductor light-emitting device 100 is 0.4 or more and 0.9 or less of the maximum value of the intensity of light in the semiconductor light-emitting device 100. The intensity of light with a wavelength of 480 nm in the semiconductor light-emitting device 100 is 0.8 or more and 0.95 or less of the maximum value of the intensity of light in the semiconductor light-emitting device 100.SELECTED DRAWING: Figure 2

Description

The technical fields of the present specification relate to crop production methods and semiconductor light emitting devices.

Plants use light energy to perform photosynthesis, which synthesizes organic substances such as glucose. Therefore, among the plant factories that produce crops, there are factories that cultivate crops by lighting. Examples of the lighting include fluorescent lamps and LEDs. Therefore, LED lighting has been researched and developed as a light source for growing plants.

For example, Patent Document 1 discloses a photosynthesis promoting light source having a maximum peak for all wavelength regions in a wavelength region of 610 nm or more and 630 nm or less (paragraph [0007] of Patent Document 1). The intensity of light at 450 nm of the photosynthesis promoting light source is about 0.4, which is the maximum peak (FIG. 3 of Patent Document 1). Further, Patent Document 2 discloses a light emitting device having a maximum peak in a wavelength region of 430 nm or more and 475 nm or less and a valley between two peaks in a wavelength region of 410 nm or more and 430 nm or less (Patent Document 2). FIG. 4).

Japanese Unexamined Patent Publication No. 2016-122722 JP-A-2019-062185

For example, the spectrum of the light emitting device of Patent Document 2 has a large valley in the wavelength region of 410 nm or more and 430 nm or less, and there is a gap between the spectrum of this light emitting device and the spectrum of sunlight in the sea (Patent). FIG. 5 of Document 2). Light in the wavelength range of about 410 nm to 430 nm may have a positive effect on plant cultivation. A favorable effect is, for example, an improvement in the taste of crops.

An object to be solved by the technique of the present specification is to provide a method for producing an agricultural product and a semiconductor light emitting device capable of producing a delicious agricultural product.

The method for producing agricultural products in the first aspect is a method of irradiating agricultural products with light emitted by a semiconductor light emitting device. The intensity of light having a wavelength of 430 nm in the semiconductor light emitting device is 0.4 or more and 0.9 or less, which is the maximum value of the light intensity in the semiconductor light emitting device. The intensity of light having a wavelength of 480 nm in the semiconductor light emitting device is 0.8 or more and 0.95 or less, which is the maximum value of the light intensity in the semiconductor light emitting device.

The crops produced by this crop production method are sweet and delicious. In addition, the method of producing agricultural products is expected to increase the yield. And, in this crop production method, the bactericidal action of the fungus that tries to propagate in the crop is expected.

In the present specification, a method for producing an agricultural product and a semiconductor light emitting device capable of producing a delicious agricultural product are provided.

It is a schematic block diagram of the semiconductor light emitting device of 1st Embodiment. It is a graph which shows the spectrum of the semiconductor light emitting device of 1st Embodiment. It is a graph which compares the spectrum of the semiconductor light emitting device of 1st Embodiment with the spectrum of other semiconductor light emitting device. It is a graph which shows the photosynthetic action curve. It is a photograph showing the cultivation process of leaf lettuce. It is a table that summarizes the impressions of the leaf lettuce tasting. It is a graph which shows the evaluation of the taste of leaf lettuce. It is a table which compares the components of leaf lettuce cultivated using a semiconductor light emitting device and a fluorescent lamp.

Hereinafter, specific embodiments will be described with reference to a method for producing agricultural products and a semiconductor light emitting device as an example. However, the techniques herein are not limited to these embodiments.

(First Embodiment)
The method for producing an agricultural product according to the first embodiment is a method for growing an agricultural product by irradiating the agricultural product with light emitted by a semiconductor light emitting device having a spectrum close to that of sunlight. Therefore, first, the semiconductor light emitting device will be described.

1. 1. Semiconductor light emitting device FIG. 1 is a schematic configuration diagram of the semiconductor light emitting device 100 of the first embodiment. As shown in FIG. 1, the semiconductor light emitting device 100 includes a light emitting element 110, a lead frame 120, a bonding wire 130, a case 140, a sealing resin 150, and a phosphor 160.

The light emitting element 110 is, for example, a semiconductor light emitting device that emits light having a wavelength of 410 nm or more and 425 nm or less.

The lead frame 120 is a fixing member for fixing the light emitting element 110. The lead frame 120 has a conductive material such as Ag, Cu, and Al. The lead frame 120 may have various circuits.

The bonding wire 130 is a wiring for conducting the electrode of the light emitting element 110 to the power supply unit of the lead frame 120.

The case 140 is for filling the sealing resin 150. The case 140 has a reflecting surface 141 for reflecting the light from the light emitting element 110.

The sealing resin 150 is a resin for sealing the light emitting element 110. The sealing resin 150 covers the light emitting element 110, the lead frame 120, the bonding wire 130, and the inside of the case 140. The sealing resin 150 contains various phosphors 160.

The phosphor 160 emits fluorescence using the light emitted by the light emitting element 110 as an excitation source. That is, the phosphor 160 converts the wavelength of the light emitted from the light emitting element 110. The phosphor 160 includes a first phosphor group, a second phosphor group, and a third phosphor group. The first group of phosphors includes at least one fluorescent substance that emits fluorescence having a peak wavelength of 445 nm or more and 490 nm or less. The second group of phosphors includes at least one fluorescent substance that emits fluorescence having a peak wavelength of 491 nm or more and 600 nm or less. The third group of phosphors includes at least one fluorescent substance that emits fluorescence having a peak wavelength of 601 nm or more and 670 nm or less.

The first group of phosphors is a group of bluish phosphors. The first group of phosphors includes, for example, alkaline earth halophosphate phosphors. Table 1 shows the main composition of alkaline earth halophosphate phosphors.

The second group of fluorescent substances is a group of yellowish to orange fluorescent substances. The second phosphor group includes, for example, Ca solid-soluble α-sialone phosphor, β-sialon phosphor, silicate phosphor, nitride phosphor, LSN phosphor, YAG phosphor, and LuAG phosphor. Includes at least one type. Table 2 shows the main compositions of these phosphors.

The third group of fluorescent substances is a group of red-based fluorescent substances. The third group of phosphors includes, for example, at least one of CASN phosphors, SCASN phosphors, and CASON phosphors. Table 3 shows the main compositions of these phosphors.

By combining these phosphor 160 and the light emitting element 110, it is possible to reproduce a spectrum of light close to sunlight.

2. Spectrum of Semiconductor Light Emitting Device FIG. 2 is a graph showing the spectrum of the semiconductor light emitting device 100 of the first embodiment. The horizontal axis of FIG. 2 is the wavelength of light. The vertical axis of FIG. 2 is the intensity of light of that wavelength. In FIG. 2, the light intensity is standardized with the maximum value set to 1.

As shown in FIG. 2, the semiconductor light emitting device 100 has a first peak P1, a second peak P2, and a third peak P3. The light intensity increases in the order of the first peak P1, the second peak P2, and the third peak P3. That is, the first peak P1 is the maximum peak.

The first peak P1 of the semiconductor light emitting device 100 exists in a wavelength region of 500 nm or more and 540 nm or less. The wavelength of the first peak P1 is around 520 nm.

The second peak P2 of the semiconductor light emitting device 100 exists in a wavelength region of 600 nm or more and 640 nm or less. The wavelength of the second peak P2 is in the vicinity of 620 nm. The size of the second peak P2 is 0.95 or more and less than 1 of the size of the first peak P1. More specifically, it is about 0.98. That is, the size of the second peak P2 is very close to the size of the first peak P1.

The third peak P3 of the semiconductor light emitting device 100 exists in the wavelength region of 410 nm or more and 440 nm or less. The wavelength of the third peak P3 is in the vicinity of 435 nm. The size of the third peak P3 is 0.8 or more and 0.9 or less of the size of the first peak P1. More specifically, it is about 0.88.

The intensity of light having a wavelength of 430 nm in the semiconductor light emitting device 100 is 0.4 or more and 0.9 or less, which is the maximum value of the light intensity in the semiconductor light emitting device 100. Preferably, it is 0.7 or more and 0.9 or less. More preferably, it is 0.75 or more and 0.88 or less.

The intensity of light having a wavelength of 480 nm in the semiconductor light emitting device 100 is 0.8 or more and 0.95 or less, which is the maximum value of the light intensity in the semiconductor light emitting device 100. Preferably, it is 0.85 or more and 0.93 or less.

The light intensity in the wavelength region of 425 nm or more and 650 nm or less is 0.8 or more and 1 or less of the maximum value of the light intensity. That is, the semiconductor light emitting device 100 emits light having a very broad spectrum. In the wavelength region longer than the wavelength at which the second peak P2 is taken, the longer the wavelength of light, the lower the intensity of light. The intensity of green light in the wavelength region from 460 nm to 500 nm is 0.85 or more and 0.95 or less, which is the maximum value of light intensity. Further, the intensity of green light in the wavelength region from 460 nm to 500 nm is about the same as that of blue light. In the wavelength region from 460 nm to 500 nm, the longer the wavelength of light, the higher the intensity of light tends to be. As described above, the spectrum of the semiconductor light emitting device 100 is close to the sunlight spectrum.

The light intensity in the wavelength region of 660 nm or more and 700 nm or less is 0.3 or more and 0.8 or less, which is the maximum value of the light intensity. The intensity of light having a wavelength of 700 nm in the semiconductor light emitting device 100 is 0.3 or more and 0.4 or less, which is the maximum value of the light intensity in the semiconductor light emitting device 100.

FIG. 3 is a graph comparing the spectrum of the semiconductor light emitting device 100 of the first embodiment with the spectrum of other semiconductor light emitting devices. In FIG. 3, in addition to the spectrum of the semiconductor light emitting device 100 of the first embodiment, the spectrum of the blue excitation LED and the blue excitation high color rendering LED are shown. In FIG. 3, the light intensity is standardized with the maximum value of the blue excitation high color rendering LED as 1.

As shown in FIG. 3, the intensity of light having a wavelength of 420 nm or more and 430 nm or less in the blue excitation high color rendering LED is 0.05 or less, which is the maximum value in the blue excitation high color rendering LED. On the other hand, the intensity of light having a wavelength of 420 nm or more and 430 nm or less in the semiconductor light emitting device 100 of the first embodiment is about 0.4, which is the maximum peak in the blue excitation high color rendering LED. As described above, the spectrum of the semiconductor light emitting device 100 of the first embodiment has sufficient intensity in the wavelength region of 420 nm or more and 430 nm or less.

Further, the intensity of light having a wavelength of 480 nm or more and 490 nm or less in the blue excitation high color rendering LED is about 0.3, which is the maximum value in the blue excitation high color rendering LED. On the other hand, the intensity of light having a wavelength of 480 nm or more and 490 nm or less in the semiconductor light emitting device 100 of the first embodiment is about 0.45, which is the maximum value in the blue excitation high color rendering LED. As described above, the spectrum of the semiconductor light emitting device 100 of the first embodiment has sufficient intensity in the wavelength region of 480 nm or more and 490 nm or less.

As described above, the semiconductor light emitting device 100 of the first embodiment has sufficient light intensity in the wavelength region of 420 nm or more and 430 nm or less and the wavelength region of 480 nm or more and 490 nm or less.

3. 3. Wavelength of Light and Effect on Plants FIG. 4 is a graph showing a photosynthetic action curve. The horizontal axis of FIG. 4 is the wavelength of light. The vertical axis of FIG. 4 is the specific energy. As shown in FIG. 4, the photosynthetic sensitivity draws a curve. Photon sensitivity draws a straight line. The longer the wavelength, the higher the photon sensitivity. As shown in FIG. 5, the photosynthetic sensitivity of green light is about the same as the photosynthetic sensitivity of blue light. Thus, green light is as important to photosynthesis as blue light.

3-1.4 20 nm or more and 440 nm or less wavelength region Light in the 420 nm or more and 440 nm or less wavelength region is expected to have a certain bactericidal effect, though not as much as ultraviolet rays. In addition, light in this wavelength region has the potential to raise functional components inside plants.

3-2. Wavelength region of 460 nm or more and 500 nm or less Light in the wavelength region of 460 nm or more and 500 nm or less is not easily absorbed by the upper leaves of the plant. Therefore, light in this wavelength region easily reaches the lower leaves. If the plant is irradiated with blue light and red light, the light is hardly absorbed by the upper leaves and hardly reaches the lower leaves. As a result, the lower leaves do not grow sufficiently.

4. Agricultural product production method In the agricultural product production method of the first embodiment, the agricultural products are irradiated with the light emitted by the semiconductor light emitting device 100. A semiconductor light emitting device 100 is used for lighting in a plant factory.

The soil and water supply devices other than lighting are the same as those of conventional plant factories.

Examples of agricultural products include lettuce, ice plants, strawberries, tomatoes, cucumbers, carrots, potatoes, and other seedlings. Of course, it may be an agricultural product other than the above.

5. Effect of 1st Embodiment The crop produced by this method of producing crop has sweetness and is delicious. In addition, the method of producing agricultural products is expected to increase the yield.

In this method for producing agricultural products, a semiconductor light emitting device 100 having a higher light intensity in a wavelength region of 420 nm or more and 440 nm or less than before is used. Light in this wavelength range is expected to have some bactericidal effect. Therefore, this method of producing crops is expected to have a bactericidal action of bacteria that try to propagate in the crops.

In this method for producing agricultural products, a semiconductor light emitting device 100 having a higher light intensity in a wavelength region of 460 nm or more and 500 nm or less than before is used. Light in this wavelength range is not strongly absorbed by the upper leaves of the plant and easily reaches the lower leaves. Therefore, in this crop production method, the lower leaves can be sufficiently grown. Further, in the photosynthetic action curve, green light in the wavelength region of 460 nm or more and 500 nm or less has the same photosynthetic sensitivity as blue light, and plays an important role in photosynthesis.

6. Modification 6-1. In the first embodiment of the vinyl house, the semiconductor light emitting device 100 is installed in the plant factory. However, the semiconductor light emitting device 100 may be installed in the vinyl house. The daylight hours can be lengthened. Further, the semiconductor light emitting device 100 may be arranged in a production site where other agricultural products are produced.

6-2. Peak wavelength The light intensity of the semiconductor light emitting device 100 of the first embodiment has a first peak P1 in a wavelength region of 500 nm or more and 540 nm or less, and a second peak P2 in a wavelength region of 600 nm or more and 640 nm or less. .. Further, it has a third peak P3 in the wavelength region of 410 nm or more and 440 nm or less. Here, a semiconductor light emitting device may be used in which the second peak P2 in the wavelength region of 600 nm or more and 640 nm or less has the maximum value of the light intensity. Further, a semiconductor light emitting device in which the third peak P3 has the maximum value of the light intensity may be used. As described above, the wavelength when the light intensity of the semiconductor light emitting device 100 reaches the maximum value is preferably in the range of 410 nm or more and 440 nm or less, in the range of 500 nm or more and 540 nm or less, or in the range of 600 nm or more and 640 nm or less. Alternatively, a semiconductor light emitting device having another peak wavelength may be used. However, it is preferable that the light intensity in the wavelength region of 420 nm or more and 440 nm or less and the wavelength region of 470 nm or more and 500 nm or less is sufficiently strong.

6-3. Fluorescent material A fluorescent material other than the above may be used as the fluorescent material 160 of the semiconductor light emitting device 100.

6-4. Combination You may freely combine the above modified examples.

(Experiment)
1. 1. Cultivation 1-1. Plant Factory In the same plant factory, the case where the semiconductor light emitting device 100 of the first embodiment was arranged (Example) and the case where the fluorescent lamp was arranged (Comparative Example) were compared. The brightness when the semiconductor light emitting device 100 was arranged was 174 μmol · m ⁻² s ^-1 . The brightness when the fluorescent lamp was arranged was 295 μmolm ⁻² s ^-1 . As described above, the brightness when the semiconductor light emitting device 100 was used was about 60% of the brightness when the fluorescent lamp was used. In an existing plant factory, an experiment was conducted by exchanging a fluorescent lamp with a semiconductor light emitting device 100. Therefore, there was a difference in brightness.

Here, the brightness is the photosynthetic photon flux density (PPFD). Photosynthetic photon flux density (PPFD) represents the number of photons that can be absorbed by chlorophyll, which contributes to photosynthesis, out of the number of photons per unit area per unit time.

The distance from the floor to the light source was about 40 cm.

1-2. Agricultural crops 20 strains of leaf lettuce were cultivated as agricultural crops.

1-3. Cultivation result FIG. 5 is a photograph showing the cultivation process of leaf lettuce. The upper part of FIG. 5 shows leaf lettuce cultivated using the semiconductor light emitting device 100 of the first embodiment. The lower part of FIG. 5 shows leaf lettuce cultivated using a fluorescent lamp.

The brightness of the semiconductor light emitting device 100 of the first embodiment is about 40% lower. However, as shown in FIG. 5, the semiconductor light emitting device 100 grew leaf lettuce in the same manner as a fluorescent lamp.

Table 4 is a table comparing the yields of leaf lettuce. In Table 4, the weight per plant when leaf lettuce was cultivated using a fluorescent lamp was standardized to 1. As shown in Table 4, the weight of the leaf lettuce cultivated using the semiconductor light emitting device 100 of the first embodiment and the weight of the leaf lettuce cultivated using the fluorescent lamp were about the same. The yield was slightly smaller when cultivated using the semiconductor light emitting device 100 of the first embodiment.

However, the brightness of the semiconductor light emitting device 100 is about 60% of the brightness of the fluorescent lamp. Despite the lack of brightness, the yield of leaf lettuce cultivated using the semiconductor light emitting device 100 was sufficient.

[Table 4]
Light source Yield semiconductor light emitting device 0.93
Fluorescent lamp 1

2. Tasting The cultivated leaf lettuce was tasted in the blind. That is, without telling the tasting person which is the leaf lettuce cultivated using the semiconductor light emitting device 100, the leaf lettuce cultivated using the semiconductor light emitting device 100 and the leaf lettuce cultivated using the fluorescent lamp. I had them eat and compare. Then, we received answers about their impressions of eating each leaf lettuce and which leaf lettuce was delicious.

FIG. 6 is a table summarizing the impressions of the leaf lettuce tasting. In FIG. 6, the blank indicates that there was no particular impression. As shown in FIG. 6, many respondents answered that the leaf lettuce cultivated using the semiconductor light emitting device 100 of the first embodiment was sweeter and tastier. In addition, many respondents answered that the leaf lettuce cultivated using the semiconductor light emitting device 100 of the first embodiment was crispy.

FIG. 7 is a graph showing the evaluation of the taste of leaf lettuce. The vertical axis in FIG. 7 is the number of people who answered that it was delicious. As shown in FIG. 7, the number of people who answered that the leaf lettuce cultivated using the semiconductor light emitting device 100 of the first embodiment was delicious was 15. Five people answered that the leaf lettuce cultivated using fluorescent lights was delicious. The number of people who answered neither was two.

Thus, more respondents supported leaf lettuce cultivated in the semiconductor light emitting device 100.

3. 3. Components FIG. 8 is a table comparing the components of leaf lettuce cultivated using a semiconductor light emitting device and a fluorescent lamp. As shown in FIG. 8, the leaf lettuce cultivated using the semiconductor light emitting device 100 of the first embodiment generally contains more components.

Leaf lettuce cultivated using the semiconductor light emitting device 100 contains more components than leaf lettuce cultivated using a fluorescent lamp: protein, dietary fiber, iron, calcium, potassium, total ascorbic acid, folic acid, lutein, free glutamate, total chlorophyll. , Chlorophyll a, chlorophyll b, chlorogenic acid.

The components of leaf lettuce cultivated using a fluorescent lamp more than leaf lettuce cultivated using a semiconductor light emitting device 100 are water, vitamin A, β-carotene, and sugar content (refbrix).

Chlorogenic acid, which has an antioxidant effect, is contained as much as 27% as much as in the case of a fluorescent lamp. In addition, lutein, total chlorophyll, chlorophyll a, and chlorophyll b also have an antioxidant effect. Therefore, leaf lettuce cultivated using the semiconductor light emitting device 100 is considered to be a highly functional food having a high antioxidant effect.

(Additional note)
The method for producing agricultural products in the first aspect is a method of irradiating agricultural products with light emitted by a semiconductor light emitting device. The intensity of light having a wavelength of 430 nm in the semiconductor light emitting device is 0.4 or more and 0.9 or less, which is the maximum value of the light intensity in the semiconductor light emitting device. The intensity of light having a wavelength of 480 nm in the semiconductor light emitting device is 0.8 or more and 0.95 or less, which is the maximum value of the light intensity in the semiconductor light emitting device.

In the method for producing agricultural products in the second aspect, the wavelength when the light intensity of the semiconductor light emitting device takes the maximum value is in the range of 410 nm or more and 440 nm or less, in the range of 500 nm or more and 540 nm or less, or 600 nm or more and 640 nm or less. It is within range.

In the method for producing agricultural products according to the third aspect, the light intensity of the semiconductor light emitting device has a first peak in a wavelength region of 500 nm or more and 540 nm or less, and a second peak in a wavelength region of 600 nm or more and 640 nm or less. Have.

In the method for producing agricultural products in the fourth aspect, the light intensity of the semiconductor light emitting device has a third peak in the wavelength region of 410 nm or more and 440 nm or less.

In the method for producing agricultural products in the fifth aspect, in the wavelength region longer than the wavelength at which the second peak is taken, the longer the wavelength of light, the smaller the intensity of light.

In the method for producing agricultural products in the sixth aspect, in the wavelength region from 460 nm to 500 nm, the longer the wavelength of light, the higher the intensity of light.

The semiconductor light emitting device according to the seventh aspect includes a semiconductor light emitting device and a phosphor that converts the wavelength of light emitted from the semiconductor light emitting device. The intensity of light having a wavelength of 430 nm is 0.4 or more and 0.9 or less, which is the maximum value of light intensity. The intensity of light having a wavelength of 480 nm is 0.8 or more and 0.95 or less, which is the maximum value of light intensity.

100 ... Semiconductor light emitting device 110 ... Light emitting element 120 ... Lead frame 130 ... Bonding wire 140 ... Case 150 ... Sealing resin 160 ... Fluorescent material

Claims (7)

Irradiate crops with the light emitted by the semiconductor light emitting device,
The intensity of light having a wavelength of 430 nm in the semiconductor light emitting device is 0.4 or more and 0.9 or less, which is the maximum value of the light intensity in the semiconductor light emitting device.
A method for producing an agricultural product, which comprises that the intensity of light having a wavelength of 480 nm in the semiconductor light emitting device is 0.8 or more and 0.95 or less, which is the maximum value of the light intensity in the semiconductor light emitting device. In the method for producing agricultural products according to claim 1,
The wavelength at which the light intensity of the semiconductor light emitting device reaches the maximum value is
A method for producing an agricultural product, which comprises a range of 410 nm or more and 440 nm or less, a range of 500 nm or more and 540 nm or less, or a range of 600 nm or more and 640 nm or less. In the method for producing an agricultural product according to claim 1 or 2.
The light intensity of the semiconductor light emitting device is
It has a first peak in the wavelength region of 500 nm or more and 540 nm or less.
A method for producing an agricultural product, which comprises having a second peak in a wavelength region of 600 nm or more and 640 nm or less. In the method for producing agricultural products according to claim 3,
The light intensity of the semiconductor light emitting device is
A method for producing an agricultural product, which comprises having a third peak in a wavelength region of 410 nm or more and 440 nm or less. In the method for producing an agricultural product according to claim 3 or 4.
In the wavelength region longer than the wavelength at which the second peak is taken,
A method for producing agricultural products, including the fact that the longer the wavelength of light, the lower the intensity of light. In the method for producing an agricultural product according to any one of claims 1 to 5.
In the wavelength range from 460 nm to 500 nm
A method for producing agricultural products, including the fact that the longer the wavelength of light, the stronger the intensity of light. Semiconductor light emitting element and
A phosphor that converts the wavelength of light emitted from the semiconductor light emitting device, and
Have,
The intensity of light having a wavelength of 430 nm is 0.4 or more and 0.9 or less, which is the maximum value of light intensity.
A semiconductor light emitting device including a light intensity having a wavelength of 480 nm of 0.8 or more and 0.95 or less, which is the maximum value of the light intensity.

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