JP2012055202A - Method and facility for cultivating leaf lettuce - Google Patents

Abstract

PROBLEM TO BE SOLVED: To cultivate leaf lettuce with a kind of light-emitting diode as artificial light sources.SOLUTION: In the method for cultivating leaf lettuce in a cultivation facility equipped with artificial light sources, green light-emitting diodes are used as the artificial light sources. The peak output wavelength of the green light-emitting diodes is preferably 510-524 nm. The irradiation intensity of the light beam emitted from the green light-emitting diodes is preferably at least 200 μmolms, and it is preferable that the light beam is applied for at least 7 days consecutively.

Description

  The present invention relates to a cultivation method and cultivation facility for leaf lettuce. More specifically, the present invention relates to a leaf lettuce cultivation method suitable for growing leaf lettuce in a cultivation facility such as a plant factory and a cultivation facility such as a plant factory suitable for growing leaf lettuce.

  In recent years, cultivation of plants using cultivation facilities such as plant factories has been spreading and expanding. In cultivation facilities such as plant factories, it is possible to cultivate plants by appropriately managing room temperature, moisture, fertilizer, irradiation light to plants, etc. in a space isolated from the outside, so that it is not affected by the weather Moreover, it is possible to always supply a certain amount of plant with stable quality without being damaged by pests even without pesticides.

  Incidentally, white fluorescent lamps and cold cathode fluorescent lamps have conventionally been used as artificial light sources in cultivation facilities such as plant factories. However, although these are low in price, they cannot be said to have sufficient illuminance as an artificial light source for cultivation facilities. Accordingly, various types of cultivation facilities and the like using high-intensity lamps such as high-pressure sodium lamps and metal halide lamps as artificial light sources have been proposed (see, for example, Patent Document 1).

Japanese Patent No. 3578383

  However, high-pressure sodium lamps and metal halide lamps have high illuminance, but are expensive, and have been a factor in increasing the cost of initial investment as an artificial light source for cultivation facilities. In addition, high-pressure sodium lamps, metal halide lamps, white fluorescent lamps, cold cathode fluorescent lamps, and the like have high power consumption, which has been a factor in increasing the running cost of cultivation facilities.

  By the way, in recent years, light-emitting diodes are becoming popular as home lighting, and supply at a low price is becoming possible. The light-emitting diode has high illuminance, as is apparent from the fact that it is used for traffic lights and vehicle headlights. In addition, since the power consumption is low and high illuminance can be achieved at a low voltage, the running cost can also be suppressed, and white fluorescent lamps, cold cathode fluorescent lamps, high pressure sodium lamps, metal halide lamps, etc. were used as artificial light sources for cultivation facilities. Compared to the case, it is overwhelmingly advantageous. In addition, since the light emitting diode has one of the features that it has a long life, the cost for replacing the light source can be significantly reduced. Therefore, it can be said that using a light-emitting diode as an artificial light source for a cultivation facility is extremely advantageous.

  However, light emitting diodes basically have a narrow output wavelength range, and in order to irradiate light components necessary for good growth of plants, it is often necessary to use a combination of two types of light emitting diodes that emit different light components. It is considered a thing. However, when two types of light emitting diodes that emit different light components are used in combination, the light components irradiated by the plants may vary, resulting in variations in plant growth and the possibility of supplying stable quality plants. There is. Thus, it is considered desirable to use only one type of light-emitting diode as an artificial light source after thoroughly examining the light components necessary for good growth of plants.

  Therefore, an object of the present invention is to provide a method for cultivating a kind of light emitting diode as an artificial light source for edible popular leaf lettuce.

  Moreover, an object of this invention is to provide the cultivation facility provided with a kind of light emitting diode as an artificial light source which can cultivate very popular leaf lettuce well as food.

  In order to solve this problem, the inventors of the present application have conducted intensive research and studied light components necessary for good growth of leaf lettuce, and have come up with an unexpected fact. That is, since plants are green, the green light absorption rate of plants is low compared to light components other than green light, and the light components contributing to photomorphogenesis and photosynthesis are generally blue light and red light. It was thought. However, when a cultivation test was conducted by irradiating leaf lettuce with only green light emitted from a green light emitting diode, it was surprisingly found that leaf lettuce grows well.

  In other words, the inventors have come to know that leaf lettuce can be successfully grown by irradiation with green light, which has not been conventionally considered, and have made various studies and completed the present invention.

  That is, the leaf lettuce cultivation method of the present invention uses a green light-emitting diode as an artificial light source in the method of growing leaf lettuce in a cultivation facility equipped with an artificial light source.

  The leaf lettuce cultivation facility of the present invention is a leaf lettuce cultivation facility equipped with an artificial light source, wherein the artificial light source is a green light emitting diode.

Here, in the cultivation method and cultivation facility of leaf lettuce of this invention, it is preferable that the peak output wavelength of a green light emitting diode is 510-524 nm. In this case, leaf lettuce can be grown better. Further, it is preferable that the irradiation intensity of the light emitted from the green light emitting diode is at least 200 μmolm ⁻² s ⁻¹ and the light is irradiated continuously for at least 7 days. In this case, leaf lettuce can be grown even better.

  According to the cultivation method and cultivation facility of leaf lettuce of the present invention, it is possible to grow leaf lettuce satisfactorily using a light-emitting diode as an artificial light source. It is possible to suppress the cost for cultivation of leaf lettuce, and it is possible to provide leaf lettuce more inexpensively to consumers. Moreover, since leaf lettuce can be cultivated using only green light emitting diodes as artificial light sources, the light components irradiated to leaf lettuce vary as in the case of using two types of light emitting diodes with different light emitting components. It is possible to supply leaf lettuce having a stable quality without causing variations in the quality of leaf lettuce due to the occurrence of the above.

It is a longitudinal cross-sectional side view which shows one Embodiment of the cultivation facility of leaf lettuce of this invention. It is the emission spectrum of the green LED used in the Example. It is the emission spectrum of the white fluorescent lamp used in the Example. It is a photograph which shows the form of leaf lettuce after completion | finish of a cultivation test about Examples 1-9 and Comparative Examples 1-3. It is a comparison figure of the leaf area of the 3rd leaf of leaf lettuce after completion | finish of a cultivation test about Examples 1-9 and Comparative Examples 1-3. It is a comparison figure of the fresh weight of leaf lettuce after completion | finish of a cultivation test about Examples 1-9 and Comparative Examples 1-3. It is a comparison figure of the above-ground dry matter weight of leaf lettuce about Examples 1-9 and comparative examples 1-3 after the end of a cultivation test. It is a comparison figure of the underground part dry matter weight of the leaf lettuce about Examples 1-9 and Comparative Examples 1-3 after completion | finish of a cultivation test. It is a comparison figure of the above-ground dry matter weight / underground part dry matter weight of leaf lettuce after completion | finish of a cultivation test about Examples 1-9 and Comparative Examples 1-3. It is a comparison figure of the specific leaf area of the 3rd leaf of leaf lettuce about Examples 1-9 and Comparative Examples 1-3 after completion | finish of a cultivation test. It is a comparison figure of the photosynthesis rate of the 3rd leaf of leaf lettuce about Examples 1-9 and comparative examples 1-3 after the end of a cultivation test. It is a comparison figure of the stomatal conductance of the 3rd leaf of leaf lettuce after completion | finish of a cultivation test about Examples 1-9 and Comparative Examples 1-3. Comparative Examples 1-3 and Examples 1-9 is a comparative view of the leaf in the CO ₂ concentration of the third leaf leaf lettuce after completion growing tests. It is a comparison figure of the transpiration rate of the 3rd leaf of leaf lettuce about Examples 1-9 and Comparative Examples 1-3 after the end of a cultivation test. It is a comparison figure of the total polyphenol of the 3rd leaf of leaf lettuce after completion | finish of a cultivation test about Examples 1-9 and Comparative Examples 1-3. It is a comparison figure of the anthocyanin of the 3rd leaf of leaf lettuce after completion | finish of a cultivation test about Examples 1-9 and Comparative Examples 1-3. It is a comparison figure of the chlorogenic acid of the 3rd leaf of leaf lettuce after completion | finish of a cultivation test about Examples 1-9 and Comparative Examples 1-3. It is a comparison figure of the chicory acid of the 3rd leaf of leaf lettuce after completion | finish of a cultivation test about Examples 1-9 and Comparative Examples 1-3. It is a comparison figure of the leaf area of the 3rd leaf of leaf lettuce after completion | finish of a cultivation test about Examples 1-3, Examples 10-12, and Comparative Examples 1-3. It is a comparison figure of the fresh weight of leaf lettuce after completion | finish of a cultivation test about Examples 1-3, Examples 10-12, and Comparative Examples 1-3. It is a comparison figure of the ground part dry matter weight of leaf lettuce about Examples 1-3, Examples 10-12, and Comparative Examples 1-3 after the end of a cultivation test. It is a comparison figure of the underground part dry matter weight of leaf lettuce about Examples 1-3, Examples 10-12, and Comparative Examples 1-3 after the end of a cultivation test. It is a comparison figure of the above-ground dry matter weight / underground part dry matter weight of leaf lettuce about the Examples 1-3, Examples 10-12, and Comparative Examples 1-3 after completion | finish of a cultivation test. It is a comparison figure of the specific leaf area of the 3rd leaf of leaf lettuce after completion | finish of a cultivation test about Examples 1-3, Examples 10-12, and Comparative Examples 1-3. It is a photograph which shows the form of leaf lettuce after completion | finish of a cultivation test about Example 12 and the comparative example 1. FIG.

  Hereinafter, embodiments for carrying out the present invention will be described in detail with reference to the drawings.

FIG. 1 shows an example of an embodiment of the leaf lettuce cultivation facility of the present invention. This cultivation facility 1
It is a facility for cultivating leaf lettuce 2 (for example, hydroponics such as a liquid cultivation method, an NFT cultivation method, etc.) in a space 4 that is isolated from the outside and appropriately controlled in temperature and humidity. The leaf lettuce 2 is cultivated while its seedlings are planted on a cultivation stand 5 and irradiated with artificial light by an artificial light source 3. The artificial light source 3 is supported to the leaf lettuce 2 of the cultivation stand 5 by the support body 6 so that light can be supplemented.

  In the present invention, green light is irradiated to the seedlings of leaf lettuce 2 planted on the cultivation stand 5 using only green light emitting diodes (hereinafter sometimes referred to as green LEDs) as the artificial light source 3. Cultivate.

Specifically, the green LED used as the artificial light source 3 is a green LED having a peak output wavelength (center wavelength) in the green component region of 500 nm to 550 nm, but the peak output wavelength is in the wavelength region of 510 nm to 530 nm. It is preferable to use a green LED that is positioned, more preferable to use a green LED that is located in a wavelength region having a peak output wavelength of 510 nm to 524 nm, and particularly preferable to use a green LED that has a peak output wavelength of 510 nm. As the peak output wavelength of the green LED is closer to 510 nm, the leaf length of leaf lettuce is shortened to suppress the length of the green LED and cultivated using a white fluorescent lamp (photosynthetic effective photon flux: about 100 μmolm ⁻² s ⁻¹ ) as an artificial light source It becomes easy to cultivate leaf lettuce in an excellent form (number of leaves, leaf area, specific leaf area, etc.) equal to or more than leaf lettuce. Moreover, it becomes easy to increase the total polyphenol and anthocyanin in a leaf.

  Note that the light emitted from the green LED contains more light components (blue light) less than 500 nm as the peak output wavelength is shortened in the green component region of 500 nm to 550 nm. However, even if the leaf lettuce 2 is cultivated only with light in the blue light region, poor growth occurs. Specifically, the leaves do not expand and accumulate polyphenols and dwarf. Therefore, the effect of the present invention is not achieved only by the blue light component, but by some contribution to the growth of leaf lettuce 2 by the green light component. In other words, the present invention is a novel and extremely new discovery that has been made by finding that the growth of leaf lettuce 2 can be improved by the contribution of green light, which has not previously been considered to contribute to photomorphogenesis and photosynthesis. It is an epoch-making invention.

If the intensity of green light (photosynthesis effective photon flux) to leaf lettuce 2 by a green LED is 100 μmolm ⁻² s ⁻¹ , leaflets of leaflet can be unfolded and grown, and photosynthesis is also performed. However, it is preferably at least 200 μmolm ⁻² s ^−1, more preferably at least 300 μmolm ⁻² s ^−1, and particularly preferably 500 μmolm ⁻² s ^−1. . By increasing the irradiation intensity, the leaf length of leaf lettuce is shortened to reduce the length of the leaf, promote photosynthesis, and cultivate using a white fluorescent lamp (photosynthesis effective photon flux: about 100 μmolm ⁻² s ⁻¹ ) as an artificial light source. It becomes easy to cultivate leaf lettuce in an excellent form (number of leaves, leaf area, specific leaf area, etc.) equal to or more than leaf lettuce. However, if the irradiation intensity is increased too much, the growth may be slowed. Therefore, it is preferable that the irradiation intensity be 600 μmolm ⁻² s ⁻¹ at the maximum. In particular, 300~500μmolm ^-2 s ^-1 irradiation intensity peak output wavelength using the green LED of 510 nm, preferably by a 500μmolm ^-2 s ^-1, white fluorescent lamp as an artificial light source (photosynthetic photon flux : About 100 μmolm ⁻² s ⁻¹ ), it becomes easier to grow leaf lettuce in a form superior to leaf lettuce grown using In other words, a leaf lettuce having a form equivalent to or superior to that of leaf lettuce cultivated using a white fluorescent lamp (photosynthesis effective photon flux: about 100 μmolm ⁻² s ⁻¹ ) as an artificial light source in a shorter period of time. Obtainable.

Here, as the irradiation intensity is increased, antioxidant components such as total polyphenols, chlorogenic acid, and chicory acid in the leaves and pigment components such as anthocyanins are likely to increase. In particular, when a green LED with a peak output wavelength of 510 nm is used and the irradiation intensity is 600 μmolm ⁻² s ⁻¹ , cultivation is performed using a white fluorescent lamp (photosynthesis effective photon flux: about 100 μmol ⁻² s ⁻¹ ) as an artificial light source. The red color is superior to the leaf lettuce. Furthermore, it is considered that antioxidant components such as total polyphenol, chlorogenic acid, and chicory acid also increase. However, when the irradiation intensity and 600μmolm ^-2 s ^-1, growth is slower than when the irradiation intensity was 300~500μmolm ^-2 s ^-1. Therefore, at the stage of leaf lettuce growth, the conditions are such that the leaf lettuce is cultivated in an excellent condition in a short period of time, and the anthocyanins in the leaves are increased before shipping to improve the red color. Further, it is preferable to cultivate under the condition that the antioxidant components such as total polyphenol, chlorogenic acid, and chicory acid in the leaf can be increased. Specifically, for example, after the peak output wavelength 300~500μmolm ^-2 s ^-1 irradiation intensity using the green LED of 510 nm, preferably has grown as 500μmolm ^-2 s ^-1, a peak output before shipment What is necessary is just to make it cultivate as irradiation intensity | strength as 600 micromol ^<-2 > s ^{< -1} > using green LED with a wavelength of 510 nm.

  Here, leaf lettuce does not adversely affect the growth even if it continues to be irradiated with light. According to the experiments by the present inventors, it has been confirmed that even if the green light emitted from the green LED is continuously irradiated for 7 days, it does not cause a problem in growth but rather grows well. The light may continue to be irradiated throughout the day. Therefore, it is possible to reduce the number of times the green LED is turned on and off, thereby preventing the failure and deterioration of the green LED. Moreover, since cultivation can be continued by irradiating green light all day, the cultivation facility 1 is preferably a completely artificial light type facility that does not use sunlight. Therefore, leaf lettuce can be cultivated stably without being affected at all by low sunshine. In addition, since it can be cultivated only with green light, it can be cultivated without the presence of ultraviolet rays in the cultivating facility 1, so that risks such as health damage to workers due to ultraviolet rays can be completely removed from the cultivating facility. It also has excellent merits.

  Also, if the period of green light irradiation to leaf lettuce 2 is too short, leaf lettuce 2 may not be able to grow well, so it is preferable to set it for at least 7 days. Moreover, the upper limit of the irradiation period is not particularly limited. For example, you may continue irradiating green light just before shipment.

  The above-described embodiment is an example of a preferred embodiment of the present invention, but is not limited thereto, and various modifications can be made without departing from the gist of the present invention. For example, in the above-described embodiment, the green light emitted from the green LED is continuously irradiated for 24 hours, but this is not an essential condition in the leaf lettuce cultivation method of the present invention, and is appropriately irradiated. You may make it shorten time.

  Moreover, although the above-mentioned embodiment demonstrated the case where green LED was used as an artificial light source of the completely artificial light type cultivation facility which does not use sunlight together, as an artificial light source of the sunlight combined use type cultivation facility which used sunlight together A green LED may be used. In this case, it is presumed that growth can be promoted by continuously irradiating the green light with the green LED in the time zone when the sunlight is not irradiated.

  Moreover, in the cultivation method of leaf lettuce of this invention, since the especially outstanding effect was acquired by using the green LED whose peak output wavelength is 510 nm, the short wavelength side (around 480 nm-500 nm) of this green LED The peak output wavelength may be shifted to a wavelength longer than 510 nm by simulating the spectral intensity and shape of the above. Since it is possible to appropriately design an LED having desired emission characteristics (spectral intensity and shape), a green LED having such emission characteristics is produced and used as an artificial light source for leaf lettuce cultivation. It is possible.

  Examples of the present invention will be described below, but the present invention is not limited to these examples.

The cultivation test of leaf lettuce 2 was performed using the cultivation apparatus 1 mentioned above. Leaf lettuce was subjected to a cultivation test after raising seedlings according to the following procedure. In other words, leaf lettuce (red leaf lettuce “evening red fire”) is seeded on urethane that has sufficiently absorbed water, and photosynthesis effective photon flux (PPF) is used as an artificial light source under conditions of air temperature 21-23 ° C. and relative humidity 40%. Using a white fluorescent lamp of 100 μmol · m ⁻² · s ⁻¹ (manufactured by Mitsubishi Electric Co., Ltd., trade name: Lupica 3-wavelength straight tube fluorescent lamp FLR110H / EX-W / A / 100), the seedlings were grown for 14 hours. . Seven days after sowing, a 1/2 concentration (EC: 1.2 dS / m, pH 5.8) of the Otsuka House Fertilizer A prescription culture solution was applied. Ten days after sowing, the seedlings that were raised were planted on a plate with a planting interval of 10 cm, and the type of artificial light source and the photosynthetic effective photon flux in an artificial weather room with an air temperature of 25 ° C., a relative humidity of 60%, and a CO ₂ concentration of 900 μmol · mol ^−1. (PPF) was varied, and liquid culture culture was performed and a cultivation test was performed.

Example 1
The artificial light source was a green LED (manufactured by CCS, ISL-305X302-BBBB50), and PPF was 100 μmol · m ⁻² · s ⁻¹ (hereinafter referred to as PPF100), and light irradiation was performed continuously for 7 days. The green LED used in Example 1 had a center wavelength (peak output wavelength) of 510 nm, a full width at half maximum of 24 nm, and an output wavelength range of 480 to 562 nm (an emission spectrum is shown in FIG. 2). Hereinafter, the green LED used in Example 1 is referred to as G510.

(Example 2)
The conditions were the same as in Example 1 except that PPF was changed to 200 μmol · m ⁻² · s ⁻¹ (hereinafter referred to as PPF200).

Example 3
The conditions were the same as in Example 1 except that PPF was changed to 300 μmol · m ⁻² · s ⁻¹ (hereinafter referred to as PPF300).

Example 4
The artificial light source was a green LED different from Example 1 (CCS, ISL-305X302-GGGG), and PPF100 was irradiated with light for 7 consecutive days. The green LED used in Example 4 had a center wavelength (peak output wavelength) of 524 nm, a full width at half maximum of 28 nm, and an output wavelength range of 486 to 580 nm (an emission spectrum is shown in FIG. 2). Hereinafter, the green LED used in Example 4 is referred to as G520.

(Example 5)
The conditions were the same as in Example 4 except that PPF200 was used.

(Example 6)
The conditions were the same as in Example 4 except that PPF300 was used.

(Example 7)
The artificial light source is a green LED different from those of Examples 1 and 4 (CCS, ISL-305X302-GGGG, the green LED used in Example 4 has the same model number but the product is different), and PPF100 is lighted continuously for 7 days. Irradiation was performed. The green LED used in Example 7 had a center wavelength (peak output wavelength) of 532 nm, a full width at half maximum of 34 nm, and an output wavelength range of 483 to 602 nm (emission spectrum is shown in FIG. 2). Hereinafter, the green LED used in Example 7 is referred to as G530.

(Example 8)
The conditions were the same as in Example 7 except that PPF200 was used.

Example 9
The conditions were the same as in Example 7 except that PPF300 was used.

(Comparative Example 1)
The artificial light source was a white fluorescent lamp (manufactured by OSRAM, FL), and PPF100 was irradiated with light for 7 consecutive days. This condition is a general condition for cultivating leaf lettuce in a cultivation facility such as a plant factory, and the subsequent examination is performed based on the form of leaf lettuce in Comparative Example 1 as a reference.

(Comparative Example 2)
The conditions were the same as in Comparative Example 1 except that PPF200 was used.

(Comparative Example 3)
The conditions were the same as in Comparative Example 1 except that PPF300 was used.

(Example 10)
The conditions were the same as in Example 1 except that PPF was changed to 400 μmolm ⁻² s ⁻¹ (hereinafter referred to as PPF400).

(Example 11)
The conditions were the same as in Example 1 except that PPF was changed to 500 μmolm ⁻² s ⁻¹ (hereinafter referred to as PPF500).

(Example 12)
The conditions were the same as in Example 1 except that PPF was changed to 600 μmolm ⁻² s ⁻¹ (hereinafter referred to as PPF600).

  The emission spectrum of the white fluorescent lamp (manufactured by OSRAM, FL) used in this example is shown in FIG.

  In this example, the photon flux was calculated from the measured value of a spectrometer (Ocean Optics).

  In Examples 1 to 12 and Comparative Examples 1 to 3, six seedlings were planted on a planting plate, and the average value was used as experimental data. For PPF100 and 200, the planting interval was set to a maximum of 12 cm and a minimum of 8 cm, and for PPF300, 400, 500 and 600, the planting interval was set to a maximum of 18 cm and a minimum of 8 cm.

  About Examples 1-9 and Comparative Examples 1-3, the form of the leaf lettuce after completion | finish of a cultivation test is shown in FIG. Moreover, about Examples 1-9 and Comparative Examples 1-3, the number of leaves of leaf lettuce after a cultivation test and the form (leaf length, leaf width, petiole length, petiole width) of the 3rd leaf are shown in Table 1.

  As is clear from FIG. 4, in Comparative Example 3 (white fluorescent lamp, PPF300), the leaf lettuce leaves were tinged with a strong red color without sufficiently developing, resulting in poor growth. On the other hand, in Examples 1 to 9 in which the light source is a green LED, the leaf was grown in a state where leafs of leaf lettuce were firmly developed. Therefore, it was revealed that leaflets of leaf lettuce can be firmly developed and grown by using a green LED as the light source.

  Further, as apparent from FIG. 4 and Table 1, in Example 7 (G530, PPF100), the petiole length was long and long, but this was improved by using a green LED of G510 or G520 (implementation). Examples 1, 4). Further, the PPF was improved to 200 or 300 (Examples 8 and 9).

  Furthermore, from FIG. 4 and Table 1, as the center wavelength of the green LED is shortened, and as the PPF of the green LED is increased, the length of the petiole is shortened and the length is reduced, and the comparative example 1 is cultivated with a white fluorescent lamp. (PPF100) can be brought close to the form of leaf lettuce. In particular, in Example 3 (G510, PPF300), compared with leaflet of Comparative Example 1 (PPF100) cultivated with a white fluorescent lamp, the number of leaves and petiole As the width increased remarkably, the petiole length was remarkably suppressed, and the leaf lettuce form was extremely excellent. In other words, it became clear that leaf lettuce having a quality equivalent to or higher than that of Comparative Example 1 (PPF100) cultivated with a white fluorescent lamp can be obtained in a shorter period of time.

Next, about Examples 1-9 and Comparative Examples 1-3, the leaf area (cm < ² >) of leaf lettuce after completion | finish of a cultivation test is shown in FIG. 5, and fresh weight (mg) is shown in FIG. In addition, the leaf area of FIG. 5 is a result about a 3rd leaf. In Example 3 (G510, PPF300), both leaf area and fresh weight were almost the same as the leaf lettuce of Comparative Example 1 (PPF100) cultivated with a white fluorescent lamp.

  Next, about Examples 1-9 and Comparative Examples 1-3, the above-ground dry matter weight (mg) of the leaf lettuce after completion | finish of a cultivation test is shown in FIG. 7, and an underground part dry matter weight (mg) is shown in FIG. Here, the smaller the ratio of aboveground dry matter weight (mg) to underground dry matter weight (mg), the root grows more firmly and takes up moisture containing nutrients into the aboveground part. It becomes easy and the quality of leaf lettuce becomes excellent. Accordingly, FIG. 9 shows the result of calculating the ratio of the above-ground dry weight (mg) to the above-ground dry weight (mg) (the above-ground / underground ratio). From the results shown in FIG. 9, Example 2 (G510, PPF200), Example 3 (G510, PPF300), Example 5 (G520, PPF200), Example 6 (G520, PPF300), Example 8 (G530, In PPF200) and Example 9 (G520, PPF300), it became clear that the value of the above-ground part / underground part ratio was significantly smaller than the leaf lettuce of Comparative Example 1 (PPF100) cultivated with a white fluorescent lamp. From this result, it is clear that by setting the PPF of the green LED to 200 or more, roots can be grown more firmly than the leaf lettuce of Comparative Example 1 (PPF100) cultivated with a white fluorescent lamp, and the quality can be improved. It was.

Next, about Examples 1-9 and Comparative Examples 1-3, the specific leaf area (cm < ² > mg <^-1> ) of the 3rd leaf of leaf lettuce after completion | finish of a cultivation test is shown in FIG. The smaller the specific leaf area, the thicker and thicker the leaves are formed, the better the quality of leaf lettuce. From the results shown in FIG. 10, the specific leaf area tends to decrease as the PPF increases. Also, Example 2 (G510, PPF200), Example 3 (G510, PPF300), Example 5 (G520, PPF200), Example 6 (G520, PPF300), Example 8 (G530, PPF200), Example 9 In (G520, PPF300), it was revealed that the specific leaf area was smaller than the leaf lettuce of Comparative Example 1 (PPF100) cultivated with a white fluorescent lamp. From this result, by setting the PPF of the green LED to 200 or more, a leaf that is thicker than the leaf lettuce of Comparative Example 1 (PPF100) cultivated with a white fluorescent lamp is formed, and the quality of leaf lettuce is improved. It became clear that it could be raised.

Next, for Examples 1 to 9 and Comparative Examples 1 to 3, the photosynthesis rate, stomatal conductance, CO ₂ concentration in leaf, and transpiration rate of the third leaf of leaf lettuce after the cultivation test were measured. For the measurement, a photosynthetic transpiration measuring device LI-6400 (manufactured by LI-COR) was used. A microchamber dedicated to Arabidopsis was used for the leaf chamber, and the photosynthetic rate, stomatal conductance, intra-leaf CO ₂ concentration, and transpiration rate under various artificial light sources were measured. The measurement results of the photosynthetic rate (molCO ₂ m ^-2 s ^-1) shown in FIG. 11 shows the measurement results of stomatal conductance (mol m ^-2 s ^-1) in FIG. 12, leaves the CO ₂ concentration (molCO ₂ m ^-2 s ^-1 ) measurement results are shown in FIG. 13, and the transpiration rate (molH ₂ O ₂ m ^-2 s ^-1 ) measurement results are shown in FIG.

Here, stomatal conductance is a value that serves as an index of the opening of the pores for taking carbon dioxide into the leaf. The larger the value, the easier the carbon dioxide is taken into the leaf, and the photosynthetic reaction progresses better. It becomes easy to do. In addition, the CO ₂ concentration in the leaf is the CO ₂ concentration remaining in the leaf, and the value decreases as the photosynthetic reaction proceeds better. Furthermore, the transpiration rate is a rate at which water generated by the photosynthetic reaction is transpired from the leaf, and the value increases as the photosynthetic reaction proceeds better.

  From the results shown in FIG. 11 to FIG. 14, it was clarified that the photosynthesis reaction can proceed in the leaf of leaf lettuce by irradiating green light using a green LED (Example 1). ~ 9).

  Further, from the results shown in FIGS. 11 to 14, Example 2 (G510, PPF200), Example 3 (G510, PPF300), Example 5 (G520, PPF200), Example 6 (G520, PPF300), Implementation In Example 8 (G530, PPF200) and Example 9 (G520, PPF300), it was considered that the photosynthetic reaction was promoted more than the leaf lettuce of Comparative Example 1 (PPF100) cultivated with a white fluorescent lamp. From this result, it is considered that by setting the PPF of the green LED to 200 or more, the photosynthetic reaction can be promoted more satisfactorily than the leaf lettuce of Comparative Example 1 (PPF100) cultivated with a white fluorescent lamp. It was.

Next, about Examples 1-9 and Comparative Examples 1-3, the total polyphenol, anthocyanin, chlorogenic acid, and chicory acid of the 3rd leaf of leaf lettuce after completion | finish of a cultivation test were measured. Total polyphenol was measured by the Folin-Ciocalteu method. Anthocyanins were extracted by adding methanol containing 1% HCl to the dried sample, and the absorbance at 530 nm was measured with a microplate reader. Chlorogenic acid and chicory acid were extracted by adding 100% methanol to the dried sample, and this was measured by UPLC (Ultra (High) Performance Liquid chromatography). The measurement result of total polyphenol (μg / mg DW) is shown in FIG. 15, the measurement result of anthocyanin (OD ₅₃₀ / mg DW) is shown in FIG. 16, and the measurement result of chlorogenic acid (μg / mg DW) is shown in FIG. FIG. 18 shows the measurement results of chicoryic acid (μV / s · mg DW).

  From the results shown in FIG. 15 to FIG. 18, it has been clarified that by increasing the PPF, it is possible to increase all the polyphenols, anthocyanins, chlorogenic acids, and chicory acids in the leaves.

  Further, from the results shown in FIGS. 15 to 18, in Example 2 (G510, PPF200), Example 3 (G510, PPF300), Example 5 (G520, PPF200), and Example 6 (G520, PPF300), It was revealed that the total polyphenol and chicory acid in the leaf were increased as compared with the leaf lettuce of Comparative Example 1 (PPF100) cultivated with a white fluorescent lamp. Furthermore, about Example 3 (G510, PPF300) and Example 6 (G520, PPF300), the chlorogenic acid in a leaf is increasing rather than the leaf lettuce of the comparative example 1 (PPF100) cultivated with the white fluorescent lamp. Became clear.

  From the above results, when it is desired to increase antioxidant components such as total polyphenol, chicory acid and chlorogenic acid in the leaves, it is preferable to set the green LED to G510 or G520 and the PPF to 200 or more, and the green LED to G510 or It became clear that it is more preferable to set PPF to 300 or more as G520.

  Next, about Example 3 (G510, PPF300) whose form was superior to the leaf lettuce of Comparative Example 1 (PPF100) cultivated with a white fluorescent lamp, the effect on the growth of leaf lettuce was examined by further increasing the PPF. (Examples 10-12).

About Examples 1-3, Examples 10-12, and Comparative Examples 1-3, the leaf area (cm < ² >) of leaf lettuce after a cultivation test completion is shown in FIG. 19, and fresh weight (mg) is shown in FIG. In addition, the leaf area of FIG. 19 is a result about a 3rd leaf. In Example 3 (G510, PPF300) and Example 10 (G510, PPF400), both leaf area and fresh weight were almost equivalent to the leaf lettuce of Comparative Example 1 (PPF100) cultivated with a white fluorescent lamp. In Example 11 (G510, PPF500), both leaf area and fresh weight were significantly larger than the leaf lettuce of Comparative Example 1 (PPF100) cultivated with a white fluorescent lamp. From this result, it became clear that the growth was maximized by cultivation under the conditions of Example 11. In other words, by cultivating under the conditions of Example 11, it is clear that a leaf lettuce having a quality equivalent to or higher than the leaf lettuce of Comparative Example 1 (PPF100) grown with a white fluorescent lamp can be obtained in a shorter period of time. It became.

  Next, about Examples 1-3, Examples 10-12, and Comparative Examples 1-3, the above-ground dry matter weight (mg) of leaf lettuce after completion | finish of a cultivation test is shown in FIG. 21, and an underground part dry matter weight (mg) Is shown in FIG. Moreover, the result of having calculated the ratio (overground part / underground part ratio) of the above-ground dry matter weight (mg) with respect to an underground part dry matter weight (mg) is shown in FIG. From the results shown in FIG. 23, Example 2 (G510, PPF200), Example 3 (G510, PPF300), Example 10 (G510, PPF400), Example 11 (G510, PPF500), Example 12 (G510, In PPF600), it became clear that the value of the above-ground part / underground part ratio becomes significantly smaller than the leaf lettuce of Comparative Example 1 (PPF100) cultivated with a white fluorescent lamp. Also from this result, it is clear that by setting the PPF of the green LED to 200 or more, roots can grow more firmly than the leaf lettuce of Comparative Example 1 (PPF100) cultivated with a white fluorescent lamp, and the quality can be improved. became.

Next, about Examples 1-3, Examples 10-12, and Comparative Examples 1-3, the specific leaf area (cm < ² > mg <^-1> ) of the 3rd leaf of leaf lettuce after completion | finish of a cultivation test is shown in FIG. From the results shown in FIG. 24, it is clear that the specific leaf area tends to decrease even when the PPF is higher than 400. In Example 2 (G510, PPF200), Example 3 (G510, PPF300), Example 10 (G510, PPF400), Example 11 (G510, PPF500), and Example 12 (G510, PPF600), white fluorescence It was revealed that the specific leaf area was smaller than the leaf lettuce of Comparative Example 1 (PPF100) cultivated with a lamp. Also from this result, by setting the PPF of the green LED to 200 or more, a leaf that is thicker than the leaf lettuce of Comparative Example 1 (PPF100) cultivated with a white fluorescent lamp is formed, and the quality of leaf lettuce It became clear that it can be improved.

  Next, about Example 12 and Comparative Example 1, the form of leaf lettuce after the end of the cultivation test is shown in FIG. It was revealed that the leaf lettuce obtained in Example 12 (G510, PPF600) is superior in red coloration to the leaf lettuce of Comparative Example 1 (PPF100) cultivated with a white fluorescent lamp. However, since the leaf area is slightly smaller than the leaf lettuce of Comparative Example 1 (PPF100) cultivated with white fluorescent light (growth is slow), than the leaf lettuce of Comparative Example 1 (PPF100) cultivated with white fluorescent light The embodiment can be made excellent (Example 3 (G510, PPF400), Example 10 (G510, PPF400) or Example 11 (G510, which can obtain a leaflet of the same or higher form in a short period of time). After cultivating with PPF500), the PPF is increased to 600 before shipping to increase the red color development, so that the form and red color development are more than the leaf lettuce of Comparative Example 1 (PPF100) cultivated with white fluorescent lamp It was considered excellent and possible.

1 Cultivation facility 2 Leaf lettuce 3 Artificial light source

Claims (6)

A method for cultivating leaf lettuce in a cultivation facility equipped with an artificial light source, wherein a green light emitting diode is used as the artificial light source. The leaf lettuce cultivation method according to claim 1, wherein the green light emitting diode has a peak output wavelength of 510 to 524 nm. The cultivation method of leaf lettuce of Claim 1 or 2 which makes irradiation intensity | strength of the light emitted from the said green light emitting diode at least 200 micromol ^- 2s ^{- 1} and irradiates the said light continuously for at least 7 days. A leaf lettuce cultivation facility comprising an artificial light source, wherein the artificial light source is a green light emitting diode. The cultivation facility of leaf lettuce according to claim 4 whose peak output wavelength of said green light emitting diode is 510-524 nm. The cultivation facility of leaf lettuce according to claim 4 or 5, wherein the irradiation intensity of the light emitted from the green light emitting diode is at least 200 μmolm ⁻² s ⁻¹ and the light is irradiated continuously for at least 7 days.