JP2023110612A - Method for cultivating basil - Google Patents

Abstract

To provide a method for cultivating basil efficiently.SOLUTION: One or more embodiments of the present invention relate to a method for cultivating basil in an environment where light conditions are controlled by an artificial light source, the temperature of the environment being 23°C or higher and 37°C or lower, the artificial light source comprising an LED, and the method comprising a light irradiation step of irradiating the basil with light from the LED so that the photosynthetic photon flux density is 200 μmol/m2 sec or more.SELECTED DRAWING: None

Description

The present specification discloses a method of cultivating basil in an environment with controlled lighting conditions with artificial light sources.

2. Description of the Related Art A plant cultivating apparatus for cultivating plants by artificially controlling conditions necessary for cultivating plants, such as light and temperature, is known. A large-scale plant cultivation apparatus is also called a plant factory.

In order to increase the efficiency of plant production in a plant factory, the relationship between the light conditions of artificial light sources and the growth of plants has been studied.

For example, in Non-Patent Document 1, red leaf lettuce is subjected to three levels of photosynthetic photon flux densities (PPFD) (100, 200, 300 μmol/m ²・ sec) and 3 levels of B / R ratio (0.33, 0.23, 0.18), 9 sections, 3 levels of PPFD (100, 200, 300 μmol / m ²・ sec under white fluorescent light) ), the total leaf area increased as the PPFD increased.

In Patent Document 1, light from a light radiation source having a wavelength range of 400 to 700 nm as a main wavelength and light from a far-infrared light radiation source are combined so as to have a specific photon flux density ratio, and are irradiated. It has been described that the live weight gain of rice can be accelerated and the production turnaround time can be shortened. An example of sunflower cultivation is described in Examples of Patent Document 1.

In Patent Document 2, for promoting flowering of long-day plants, the integrated value of the photon flux with a wavelength of 700 nm to 700 nm is larger than the integrated value of the photon flux with a wavelength of 700 nm to 700 nm. A light emitting device is described. Patent Document 2 cites lilies, roses, carnations, lisianthus, gypsophila paniculata, starchia, astromeria, stock and delphinium as specific examples of long-day plants.

In Patent Document 3, in a time period when sunlight is not irradiated and at an ambient temperature of 5 to 40 ° C., the emission dominant wavelength is 700 to 800 nm, and the photon flux density in the dominant wavelength region is 0.04 μmol / Plant height growth and flowering are promoted by a method for cultivating a long-day plant characterized by comprising a step of continuously irradiating the long-day plant with far-red light so that it becomes m ² seconds or more. It is stated that Examples of Patent Document 3 describe an example of cultivating Gypsophila paniculata as a long-day plant.

JP-A-4-207127 Japanese Patent Application Laid-Open No. 2002-199816 JP-A-2005-095132

Shinichi Koyama, "Study on high-efficiency production of red leaf lettuce by light environment control", https://core.ac.uk/download/pdf/96950368.pdf

The above prior art documents do not describe temperature conditions and light conditions for improving the yield in basil cultivation.
Therefore, the present specification discloses a method for cultivating basil under an environment in which light conditions are adjusted by an artificial light source, wherein the temperature conditions and light conditions are adjusted to increase the cultivation efficiency of basil.

This specification discloses the following method as means for solving the above problems.
(1) A method of cultivating basil under an environment in which light conditions are adjusted by an artificial light source, wherein the temperature of the environment is 23°C or higher and 37°C or lower,
the artificial light source comprises an LED; and
A method comprising a light irradiation step of irradiating the basil with light from the LED so that the photosynthetic photon flux density is 200 μmol/m ² ·sec or more.
(2) The method according to (1), wherein the photosynthetic photon flux density is 440 μmol/m ² ·sec or less.
(3) a light period for performing the light irradiation step;
The method according to (1) or (2), comprising repeating a dark period in which light is not emitted from the LED.
(4) The method according to (3), wherein the light period and the dark period are repeated from germination to harvest of the basil.

Basil can be efficiently cultivated according to one or more embodiments of the present invention.

<Basil>
As used herein, "basil" refers to Ocimum basilicum L., also known as sweet basil. , Ocimum tenuiflorum, also called holy basil, and Ocimum basilicum L. or crosses of Ocimum tenuiflorum with other closely related species. Although many cultivars of basil are known, the method disclosed herein can be applied to any cultivar of basil. Ocimum basilicum L. Lemon basil can be exemplified as a hybrid between C. and other closely related species.

<Method of cultivating basil>
One or more embodiments of the present invention are a method of cultivating basil under an environment in which light conditions are adjusted by an artificial light source, wherein the temperature of the environment is 23° C. or higher and 37° C. or lower,
the artificial light source comprises an LED (light emitting diode), and
The method includes a light irradiation step of irradiating the basil with light from the LED so that the photosynthetic photon flux density is 200 μmol/m ² ·sec or more.

The method according to this embodiment can be implemented using a plant cultivation device or a plant factory. In particular, it can be preferably carried out by cultivation using only an artificial light source in which sunlight (natural light) is completely blocked. Moreover, it can be suitably carried out by hydroponics. Hydroponic culture, spray culture, solid medium culture, and the like can be exemplified as hydroponic culture.

In the method according to the present embodiment, the environmental temperature, that is, the ambient temperature of the basil in the cultivation space is adjusted to 23° C. or higher and 37° C. or lower, thereby promoting the growth of the basil and increasing the yield. can. The lower limit of the environmental temperature is more preferably 24°C or higher, still more preferably 25°C or higher, and particularly preferably 26°C or higher. The upper limit of the environmental temperature is more preferably 36° C. or lower, still more preferably 35° C. or lower, and particularly preferably 34° C. or lower.

In the method according to this embodiment, the temperature control includes a cooling device and / or a heating device that adjusts the environmental temperature, a temperature sensor installed around the basil, and information and setting of the temperature detected by the temperature sensor It can be carried out using a plant cultivation device or a plant factory that includes a control unit that controls the cooling device and/or the heating device based on temperature information. The range of temperature control by the control unit is preferably within ±2° C., more preferably within ±1° C. of the set environmental temperature.

In the light irradiation step in the method according to the present embodiment, the basil is irradiated with light from the LED so that the photosynthetic photon flux density (hereinafter sometimes abbreviated as PPFD) is 200 μmol/m ² sec or more. characterized by By adjusting the PPFD to this range, the growth of basil can be promoted and the yield can be increased. The lower limit of PPFD is more preferably 220 μmol/m ² ·sec or more, and most preferably 230 μmol/m ² ·sec or more. Although the upper limit of PPFD is not particularly limited, it is preferably 440 µmol/m ² ·sec or less, more preferably 400 µmol/m ² ·sec or less, particularly preferably 360 µmol/m ² ·sec or less, and most preferably It is 350 μmol/m ² ·sec or less. A PPFD of 440 μmol/m ² ·sec or less is preferable because the appearance and taste of the basil are improved.

According to the definition of the Photosynthesis Society of Japan, PPFD refers to the number of photons in the wavelength range from 400 nm to 700 nm that are effective for photosynthesis among the photons that pass through a unit area per unit time.

In the method according to the present embodiment, the PPFD is defined by the intensity of light on the cultivation surface such as the upper surface of the growing bed in the absence of crops (at the time of non-planting). That is, PPFD is obtained by measuring the intensity of light on the cultivation surface. For example, the average value of PPFD measured at measurement points (for example, 2 to 12 points) provided in a checkerboard pattern at equal intervals in the vertical and horizontal directions over almost the entire range of the upper surface of the growing bed is within the range specified in the present invention. I wish I could. In this case, the cultivation surface for measuring the PPFD refers to the cultivation surface and the space in the vicinity thereof, for example, the cultivation surface and the space above it (for example, the space up to about 5 cm above the cultivation surface).

In the method according to this embodiment, the distance between the cultivation surface and the LEDs may be changed continuously or stepwise over time as the basil grows. For example, the distance between the cultivation surface and the LEDs can be increased continuously or stepwise over time so that the distance between the basil leaf surface and the LEDs is substantially constant. In a mode in which the distance between the cultivation surface and the LEDs is changed continuously or stepwise over time, the distance between the cultivation surface and the LEDs is an intermediate distance (height) between the minimum value and the maximum value of the distance during cultivation. The PPFD at the time of non-planting when setting the distance to is within the above range. The means for changing the distance between the cultivation surface and the LEDs is arbitrary, such as providing the LEDs so as to be vertically movable with respect to the cultivation surface, or adjusting the height of the cultivation shelf.

LEDs (light emitting diodes) are preferred as artificial light sources. The LED may emit light within the wavelength range of 400 nm to 700 nm, which is effective for photosynthesis. Examples include LEDs emitting at least one color of red, blue, and green, and white LEDs are particularly preferred. .

In the method according to the present embodiment, the light irradiation step at the ambient temperature is performed over the entire period from germination to harvest of basil, or for a part of the period, for example, harvested seedlings after planting. It should be implemented during the period.

The method according to this embodiment preferably includes repeating a light period in which the light irradiation step is performed and a dark period in which the LED does not irradiate light. More preferably, the light period and the dark period are repeated over the entire period from germination to harvest of the basil, or during a part of the period, for example, after planting the grown seedlings.

The light period is a condition in which light from an artificial light source is applied at a light intensity that enables photosynthesis, and the light irradiated in the light period preferably does not include sunlight (natural light). The dark period refers to a period during which light from the artificial light source is not applied.

The times of the light period and the dark period can be adjusted as appropriate, but the light period is preferably longer than 13 hours, more preferably 13.5 hours or more, and particularly 14 hours or more. preferable. Further, the light period is more preferably 20 hours or less, particularly preferably 19 hours or less. The dark period is preferably 4 hours or longer, more preferably 4.5 hours or longer, and particularly preferably 5 hours or longer. The dark period is preferably 10 hours or less, more preferably less than 10 hours, still more preferably 9.5 hours or less, particularly preferably 9 hours or less, and particularly preferably 8 hours or less.

Furthermore, one cycle consisting of one light period and one dark period may be 18 hours or more, more preferably 19 hours or more, and more preferably 19.5 hours or more. Preferably, it is particularly preferably 20 hours or longer. Moreover, the period is preferably 24 hours or less, more preferably 23.5 hours or less, and still more preferably 23 hours or less. When the cycle is less than 24 hours, the cultivation period can be shortened compared to the case of 24 hours or more, and the cultivation efficiency per hour can be increased, which is preferable. In this embodiment, the light period and the dark period may be alternately repeated, and it is arbitrary whether to start from the light period or from the dark period.

The number of cycles is not particularly limited, but in a more preferred embodiment of the present invention, after planting basil seedlings, the cycle of the above conditions is repeated 5 to 10 times, and then the leaves are harvested for the first time. After 5-10 cycles of the above conditions, the leaves can be harvested a second time.

Various conditions such as humidity and CO ₂ concentration when cultivating basil in the method according to the present embodiment can be adjusted within a range suitable for cultivating basil. In the method according to the present embodiment, the relative humidity is preferably 50% or more and 90% or less, more preferably 65% or more and 80% or less, and the _CO2 concentration is preferably 500 ppm or more and 5000 ppm or less, and 750 ppm or more and 3000 ppm or less. more preferred.

<Experiment 1: Cultivation of sweet basil>
(Raising seedlings)
Sweet basil (Ocimum basilicum L.): Basilina (Futaba Seed Co., Ltd.) seeds are sown in a urethane medium soaked with nutrient solution in the cultivation room of the plant cultivation apparatus, and the long diameter of a pair of true leaves is about 60 mm. Seedlings were raised to a size that would be above.

(Cultivation of basil from seedlings)
In a cultivation room of a plant cultivation apparatus, a container with a cultivation panel floating on a nutrient solution was placed on a growth bed, and the sweet basil seedlings were planted permanently on the cultivation panel. The cultivating panels are two approximately square ones with an area of about 0.07 m ² (about 21.5 cm × about 32.5 cm), and 4 stalks of the sweet basil seedlings are planted on each cultivating panel. bottom.

The environmental temperature of the cultivation room was set to the temperatures shown in Tables 1, 2 and 3 below, and a white LED lamp ("PGL-NE-200NWB", Ryoden Corporation) was installed above the growing bed. was used to set a light period in which light was irradiated at the photosynthetic effective quantum flux density (PPFD) shown in Tables 1, 2, and 3 below, and a dark period in which light was not irradiated, with a light-dark cycle of 24 hours (light period of 16 Light irradiation was performed so as to be time/dark period of 8 hours). In any case, the relative humidity is 75% to 90%, taking into account the saturation (the difference between the saturated water vapor pressure in the air at a certain temperature and the water vapor pressure actually contained in the air), and the _CO2 concentration is 1000. , 2000 or 2300 ppm.

In the cultivation room, the temperature of the cultivation space, i.e., the environmental temperature of the plant body, is set within a range of ±2°C around the set temperature, based on the detection of temperature sensors installed in various places in the room by the heating device and the cooling device. controlled to

The height of the cultivation space in the cultivation room was about 360 mm from the surface of the cultivation bed, and white LED lamps were arranged on the top plate. The distance between the white LED lamp and the surface of the growing bed is about 280 mm.

The photosynthetic effective quantum flux density (PPFD) was obtained by the following procedure using a LI-250A light meter manufactured by LI-COR.
That is, on each cultivation panel, six measurement points were provided in a checkerboard pattern at approximately equal intervals in the vertical and horizontal directions, and the average value of PPFD measured at each point was determined.

After planting the seedlings, light irradiation was performed by repeating the light-dark cycle seven times, and the grown basil was harvested at a cutting position about 2 cm above the lowermost leaf, and the first harvest (harvest 1) was performed.

Furthermore, basil is regenerated from the stems remaining after the first harvest, light irradiation is performed to repeat the same light-dark cycle six times, and the axillary buds grown from the vicinity of the cut position are removed from the stem below the lowermost leaf. A second harvest (harvest 2) was performed by cutting at a position where the length was about 4 cm.

In the growing bed 1 section, the average weight (yield) of the 8 basil stems harvested in Harvest 1 and Harvest 2 was measured, the quality was evaluated, and a comprehensive evaluation was performed.

The results are shown in Tables 1, 2 and 3 below. The experimental results at a set temperature of 26° C. shown in Tables 1 and 2 are the results of another experiment using another lot of basil. The experimental results shown in Table 2 are the results using only the harvested product of Harvest 1.

Conditions and results are shown in the table below.

Evaluation criteria total yield 〇: 20 g or more △: 12 g or more and less than 20 g ×: less than 12 g

Quality 〇: No problem △: Some problem (acceptable level)
×: Problematic (out of tolerance)

Comprehensive evaluation ◎: Both yield and quality are 〇 〇: One of yield and quality is 〇, the other is △
△: Both yield and quality are △
×: At least one of yield and quality is ×

Evaluation criteria total yield 〇: 15 g or more △: 10 g or more, less than 15 g ×: less than 10 g

Quality 〇: No problem △: Some problem (acceptable level)
×: Problematic (out of tolerance)

Comprehensive evaluation ◎: Both yield and quality are 〇 〇: One of yield and quality is 〇, the other is △
△: Both yield and quality are △
×: At least one of yield and quality is ×

From the results shown in Tables 1 and 2, in cultivating basil with an artificial light source, good growth was observed under the conditions that the environmental temperature was 26 ° C. or higher and 36 ° C. or lower and the PPFD was 300 μmol/m ² sec. It was confirmed that the above conditions are effective for improving the yield and quality of basil. When the ambient temperature was 38°C, both yield and quality were poor.

From the results shown in Table 3, good growth was observed under the conditions that the environmental temperature was 30° C. and the PPFD was 237.6 μmol/m ² ·sec or more and 351.7 μmol/m ² ·sec or less. It was confirmed that the conditions were effective for improving the yield and quality of basil. When the PPFD was 113.1 μmol/m ² ·sec, the yield was low, and when it was 449.4 μmol/m ² ·sec, the quality tended to be low even though the yield increased.

In particular, light irradiation at the temperature and light intensity under the above conditions is effective during the period in which basil regeneration is promoted from the stalks remaining after the first harvest.

<Experiment 2: Cultivation of other basil>
The sweet basil used in Experiment 1, two other sweet basil species: Aroma2 (Johnsons) and Campione (Kobayashi Seed Co., Ltd.), and Holy Basil (Ocimum tenuiflorum) seeds (Fujita Seed Co., Ltd.) were experimented respectively. Basil was used in place of the sweet basil (Ocimum basilicum L.) seeds used in Experiment 1, and the environmental temperature, PPFD, and _CO2 concentration described in Table 4 below were used. cultivated. For the evaluation, the first and second harvests were performed in the same procedure as in Experiment 1, and the yield was measured. Table 4 shows the conditions and results. In addition, in the experiment of sweet basil (basilina), the same variety as in experiment 1 was used, but the results were obtained in a different lot from experiment 1.

Evaluation criteria total yield 〇: 12.00 g or more △: 10.00 g or more, less than 12.00 g ×: less than 10.00 g

Another basil was observed to grow as well as the basilina used in Experiment 1 under the conditions of an environmental temperature of 26°C and a PPFD of 300 µmol/m ² ·sec. It was possible to improve the yield of basil.

<Experiment 3: Light period, dark period conditions>
(Raising seedlings)
Sweet basil (Ocimum basilicum L.): Basilina (Futaba Seed Co., Ltd.) seeds are sown in a urethane medium soaked with nutrient solution in the cultivation room of the plant cultivation apparatus, and the long diameter of a pair of true leaves is about 60 mm. Seedlings were raised to a size that would be above.

(Cultivation of basil from seedlings)
In a cultivation room of a plant cultivation apparatus, a container with a cultivation panel floating on a nutrient solution was placed on a growth bed, and the sweet basil seedlings were planted permanently on the cultivation panel. The cultivating panels are two approximately square ones with an area of about 0.07 m ² (about 21.5 cm × about 32.5 cm), and 4 stalks of the sweet basil seedlings are planted on each cultivating panel. bottom.

The environmental temperature of the cultivation room was set to a temperature of 26 ° C., and the photosynthetic effective quantum flux density (PPFD ) Light irradiation was carried out so that the conditions shown in Table 5 were met for the light period during which light irradiation was performed at 300 μmol/m ² ·sec and the dark period during which light irradiation was not performed. In both cases, the conditions were 75% relative humidity and 1000 ppm _CO2 concentration.

In the cultivation room, the temperature of the cultivation space, i.e., the environmental temperature of the plant body, is set within a range of ±2°C around the set temperature, based on the detection of temperature sensors installed in various places in the room by the heating device and the cooling device. controlled to

The height of the cultivation space in the cultivation room was about 360 mm from the surface of the cultivation bed, and white LED lamps were arranged on the top plate. The distance between the white LED lamp and the surface of the growing bed is about 280 mm.

The photosynthetic effective quantum flux density (PPFD) was obtained by the following procedure using a LI-250A light meter manufactured by LI-COR.
That is, on each cultivation panel, six measurement points were provided in a checkerboard pattern at approximately equal intervals in the vertical and horizontal directions, and the average value of PPFD measured at each point was determined.

After planting the seedlings, light irradiation was performed by repeating the light-dark cycle seven times, and the grown basil was harvested at a cutting position about 2 cm above the lowermost leaf, and the first harvest (harvest 1) was performed.

Furthermore, basil is regenerated from the stems remaining after the first harvest, light irradiation is performed to repeat the same light-dark cycle six times, and the axillary buds grown from the vicinity of the cut position are removed from the stem below the lowermost leaf. A second harvest (harvest 2) was performed by cutting at a position where the length was about 4 cm.

The average weight (yield) of the eight basil stems harvested in Harvest 1 and Harvest 2 was measured in one section (two cultivation panels) of the growing bed.

In Table 5, the yields in Harvest 1 and Harvest 2 are expressed as weight per 1 m ² of growing bed area, growing time and weight per same unit area.

Table 5 shows the results. The middle row in the frame is weight per unit area (g/m ² ), and the lower row is growth time and weight per unit area (g/m ² /h). The upper part of the frame in Table 5 shows the yield evaluation. Yield was evaluated according to the following criteria.
<Evaluation Criteria>
A: Growth time and weight per unit area (g/m ² /h) are 3.00 or more.
Good: Growth time and weight per unit area (g/m ² /h) are 2.50 or more and less than 3.00.
Δ: Growth time and weight per unit area (g/m ² /h) are 2.00 or more and less than 2.50.
x: Growth time and weight per unit area (g/m ² /h) are less than 2.00.

Claims (4)

A method for cultivating basil under an environment in which light conditions are adjusted by an artificial light source,
The temperature of the environment is 23° C. or higher and 37° C. or lower,
the artificial light source comprises an LED; and
A method comprising a light irradiation step of irradiating the basil with light from the LED so that the photosynthetic photon flux density is 200 μmol/m ² ·sec or more. 2. The method of claim 1, wherein the photosynthetic photon flux density is less than or equal to 440 [mu]mol/m ^<2> .s. A light period for performing the light irradiation step;
3. The method of claim 1 or 2, comprising repeating a dark period in which the LED is not illuminated. 4. The method of claim 3, wherein the light and dark periods are repeated after germination of the basil until harvest.