JPH09275779A - Raising of plant and apparatus for raising - Google Patents

Abstract

PROBLEM TO BE SOLVED: To regulate nutrient ingredients in a plant such as a glucide and vitamins with a small irradiation dose, promote the growth and reduce the power consumption by irradiating a plant with specific artificial light and raising the plant without changing the emission spectrum. SOLUTION: A plant 12 is irradiated with artificial light having a fluctuation component imparted to the luminance to promote the growth and raise the plant 12. The artificial light is a continuous light in the manner of a time series or intermittent pulsed light. The fluctuation component is preferably imparted to the luminance of the continuous light or the period and/or the luminance of the pulsed light.

Description

Detailed Description of the Invention

[0001]

BACKGROUND OF THE INVENTION 1. Field of the Invention The present invention relates to a plant growing method and a growing device for irradiating a plant with artificial light to promote the growth of the plant.

[0002]

2. Description of the Related Art Conventionally, fluorescent lamps or high-intensity lamps such as high-pressure discharge lamps have been used as artificial light sources for growing plants indoors. However, these light sources have poor energy efficiency of light emission and the lamp lighting. It has been pointed out that it is necessary to use an air conditioner together to prevent heat generation, and radiation of wavelengths unrelated to plant growth consumes unnecessary energy.

Although LEDs (light emitting diodes) were considered to be useful as means for solving the problems of these light sources, L which emits blue light necessary for growing plants is used.
Since there was no ED, practical application as a light source for growing plants has hardly progressed.

In 1993, L emitting high-intensity blue light
We succeeded in developing ED, and started an attempt to grow plants using LEDs. The possibility of growing various plants in a normal form was suggested by making a light source in which blue LEDs and red LEDs were mixed in an appropriate ratio (Journal of the Horticultural Society of Japan 64
Another 1 (1995): 390-391).

Further, when the LED was pulse-lighted with a cycle of 100 μs or less, a duty ratio of 50% and a power consumption of 100 W / m ² , a growth promoting effect of about 20% was recognized in comparison with continuous light (Japan Plant Factory Society). 1995 Annual Meeting, Academic Lecture Summary: 17-2).

[0006]

SUMMARY OF THE INVENTION An object of the present invention is to pay attention to the characteristic that the brightness of light and the pulse period can be electrically controlled without changing the emission spectrum. An object of the present invention is to provide a plant growing method and a growing device capable of growing a plant.

[0007]

In order to achieve the above object, the method of the present invention is a plant growing method for accelerating the growth of a plant by irradiating the plant with artificial light. Is given.

Further, the method of the present invention is a plant growing method for irradiating a plant with artificial light to promote the growth of the plant, wherein the artificial light is continuous light which is continuous in time series, and the brightness of the continuous light is high. It is characterized by giving a fluctuation component to the.

Further, the method of the present invention is a plant growing method for irradiating a plant with artificial light to promote the growth of the plant, the artificial light being pulsed light which is intermittent in time series, and the cycle of the pulsed light. And / or providing a fluctuation component to the brightness. Here, the fluctuation component may be added to the non-light emission cycle of the pulsed light, or may be added to the light emission cycle of the pulsed light.

Further, the device of the present invention comprises a light emitting diode for irradiating a plant with artificial light, a driving means for supplying a driving current to the light emitting source, and a control signal for mixing a fluctuation component into the driving current. And a control means for giving to. Here, the light emitting diode specifically includes a light emitting diode group including a plurality of red light emitting diodes, a plurality of green light emitting diodes, and a plurality of blue light emitting diodes. When supplying a drive current to the light emitting diode, the drive current may be a current that is continuous in time series, and the control means may give a fluctuation component to the amplitude of the drive current. The drive current may be a pulse current that is intermittently time-sequential, and the control means may give a fluctuation component to the off-duty cycle or the on-duty cycle of the pulse current.

According to the plant growing method and growing apparatus of the present invention described above, it is possible to adjust the nutrient components such as sugars and vitamins in the plant with a small irradiation amount to promote the growth, and to consume the plant. Power savings can be achieved.

[0012]

BEST MODE FOR CARRYING OUT THE INVENTION Preferred embodiments of the present invention will be described below with reference to the drawings.

(I) Principle In general, when a plant body is irradiated with artificial light, a voltage (leaf surface potential) is generated on the leaf of the plant, and the ionic current amount in the plant due to the leaf surface potential is related to the growth of the plant. It is known to be doing. In this case, the “fluctuation component” is added to the artificial light that is emitted.
It was confirmed that the irradiation light became closer to natural light by adding the fluctuation component, and as a result, the potential inside the plant became high potential, the ionic current increased, and the growth of the plant was promoted. .

In FIG. 2, when an LED is used as a light source and light is emitted from an LED in which a fluctuation component is added to a plant body (eg, Kapok of the family Araliaceae), the leaf potential when the fluctuation component is not added is shown. It is measured and the change in leaf potential (leaf potential difference) is shown. The light irradiation conditions were set as follows, and the leaf surface potential was measured. The configuration of the measurement system will be described together with the plant growing device described later. The measurement conditions are as follows: period T1 ... LED = ON (lighting), periodic fluctuation component addition period T2 ... LED = OFF (lighting off) period T1 ... LED = ON (lighting), no periodic fluctuation component As can be seen from the period T1 in which the fluctuation component is added
The leaf surface potential difference δ1 (about 1.37 mV) of the leaf potential difference δ2 (about 1.22) during the period T3 in which the fluctuation component is not added.
It shows a clearly high value for mV). As shown in FIG. 2, in the leaf potential waveform when the LED is turned on and off, when the LED is turned on, hyperpolarization of about 2 minutes occurs, followed by depolarization of several mV and 5 minutes. The equilibrium value is reached in some degree. The depolarization value has a correlation with the brightness of the LED.

FIG. 3 shows a diagram in which such an experiment is repeated 10 times and the values are randomized. As can be seen from FIG. 3, when the fluctuation component is added to the LED, the value of the leaf surface potential difference amount δ is high (there is a significant difference at the risk rate of 5% in the test result of the average value difference). in this way,
By adding the fluctuation component, the leaf surface potential can be increased and the ionic current can be increased, so that the plant can be activated more efficiently and the growth can be promoted.

(II) Plant Growing Device FIG. 1 shows an embodiment of a plant growing device according to the present invention to which the above principle is applied. This plant growing device includes a measurement system of leaf surface potential.

In FIG. 1, a plant 12 to be grown is arranged in a shield box 10. An LED substrate 14 serving as a light source is arranged facing the plant body 12.

The LED board 14 is a red LED and a green LE.
A large number (for example, several hundreds) of high-intensity LED elements including D and blue LEDs are arranged. The LED substrate 14 and the plant 12 are preferably close to each other in terms of light irradiation efficiency. In this regard, the conventional light source generates a large amount of heat, and the thermal influence on the plant cannot be ignored. However, in the present embodiment, since the LED with a small temperature rise is used, the plant body 12 due to the heat generation of the light source 12 is used. It is not necessary to consider the thermal influence on the light, and therefore, the irradiation efficiency of light can be improved. The LED board 14 is the computer 1
Controlled by 6.

A personal computer can be used as the computer 16, and the brightness of the LED substrate 14 is controlled according to the light irradiation control program stored in the memory. In this brightness control, fluctuation control of 1 / f to 1 / f ² is performed as described later.

A control output signal (for example, 8 bits) from the personal computer 16 is an analog voltage signal (for example, several volts) by the D / A conversion board 20 via the output port 18.
And the converted analog voltage signal is converted into a driving current by the V / I conversion board 22,
Is supplied to.

(III) Fluctuation Control FIGS. 3 to 8 show various optical waveforms to which the fluctuation component according to the present embodiment is added. Which of these fluctuation-controlling optical waveforms is used depends on the plant 12 to be grown.
It is appropriately selected and adopted according to the type and growing mode (size, shape, etc. of plant). The fluctuation component itself is 1 / f to 1 /
It is a fluctuation component of f2, and ^two types of irradiation light can be considered as continuous light and pulsed light as modes of addition, and there are modes of fluctuation component as shown in FIGS. 3 to 8. .

FIG. 3 shows an example in which continuous light is used as irradiation light and brightness fluctuation is added to this continuous light. In this example, a change corresponding to the fluctuation component is given to the amplitude of the continuous light, and the fluctuation control is performed. In practice, the time width t
Fluctuations can be added by changing the amplitude value for each cycle.

FIG. 5 shows an example in which pulsed light is used as the irradiation light and a fluctuation component is added to the non-emission cycle of this pulsed light. That is, the crest value of the pulsed light is constant, the emission time width t2 of the pulsed light is maintained constant, and the non-emission period t3 is controlled so as to change corresponding to the fluctuation component.

FIG. 6 shows an example in which pulsed light is used as the irradiation light and a fluctuation component is added to the light emission cycle of this pulsed light.
That is, the non-light emission time width t4 is set constant, but the light emission time width t4 of the pulsed light is controlled so as to change according to the fluctuation component.

FIG. 7 shows an example in which pulsed light is used as the irradiation light and the pulsed light is given stepwise brightness fluctuation. That is, the light emission time t6 of the pulse light is set constant, and the non-light emission time width t7 of the pulse light is also set constant.
The emission brightness is controlled so as to change stepwise according to the fluctuation component.

FIG. 8 shows an example in which pulsed light is used, the pulsed light is given stepwise luminance fluctuations, and a fluctuation component is given to the non-emission cycle of the pulsed light. That is, the emission time width t8 of the pulsed light is set to be constant,
The emission brightness changes stepwise, and the non-emission time width t9
Is controlled so as to change in accordance with the fluctuation component.

Next, the leaf surface potential measuring system will be described with reference to FIG. 1 again. As described above, the influence of the irradiation light from the LED substrate 14 on the plant 12 is evaluated by measuring the leaf surface potential generated by the irradiation. The measurement and detection of the leaf surface potential will be described below with reference to the enlarged view A of the leaf of the plant 12 shown in FIG.

A main electrode vein 26 of the leaf 24 has a dish electrode (Ag-Acl) 28 (+) which is a probe for detecting a leaf surface potential.
Side) and 30 (-side) are arranged. In addition, plant 1
2. When measuring the leaf surface potential, the plant body 12 is housed in the electromagnetic / electrostatic shield box 10 in order to remove noise due to the influence of an external magnetic field or electric field, and the leaf surface potential is measured. However, the shield box 10 is managed so that the internal temperature and humidity are always constant.

When the leaf potential of the plant 12 changes due to the irradiation of light from the LED substrate 14, the potential detected at the dish electrodes 28 and 30 is amplified by the differential amplifier 32 of good sensitivity and low noise. Amplification detection potential is A / D conversion board 34
After being converted into a digital value by, the data is input to the computer 16 through the input port 36.

Based on this input signal, the computer 16 analyzes and evaluates the effect of the plant body due to the irradiation from the LED substrate 14, displays the measurement result on the outside, and also LE
Feedback control of the irradiation amount of light from the D substrate 14 or feedback control is performed so as to keep the relative distance between the LED substrate 14 and the plant 12 constant.

If necessary, the height position of the LED substrate 14 can be automatically adjusted according to the growth of the plant body 12. This automatic height adjustment is performed by, for example, LED
An optical sensor such as a phototransistor is provided on the substrate 14, and L
The light reflected on the leaf surface of the ED is detected by an optical sensor, and the LED substrate 14 is controlled by an appropriate driving means (motor, fluid pressure cylinder, etc.) so that the detected light has a predetermined value.

[0032]

As described above, according to the present invention,
Fluctuations are added to the brightness and / or cycle of the light from the light source for growing plants, and even if the amount of irradiation to the plants is the same, the plants are efficiently grown compared to the case where no fluctuation is added. be able to.

[Brief description of drawings]

FIG. 1 is a block diagram showing a configuration of a plant growing device according to an embodiment of the present invention.

FIG. 2 is a graph showing leaf surface potential waveforms when a fluctuation component is added to light from an LED and when a fluctuation component is not added.

FIG. 3 is a graph showing a leaf surface potential change amount when a fluctuation component is added to light from an LED and when a fluctuation component is not added.

FIG. 4 is an optical waveform diagram in which continuous light is given stepwise brightness fluctuations.

FIG. 5 is an optical waveform diagram in which a fluctuation component is added to the non-emission cycle of pulsed light.

FIG. 6 is an optical waveform diagram in which a fluctuation component is added to the light emission cycle of pulsed light.

FIG. 7 is an optical waveform diagram in which pulsed light is given stepwise brightness fluctuations.

FIG. 8 is an optical waveform diagram in which the pulsed light is given a stepwise luminance fluctuation and a fluctuation component is given to the non-light emission cycle of the pulsed light.

[Explanation of symbols]

 10 shield box 12 plant 14 LED substrate 16 computer 24 leaf 26 main leaf vein 28 + plate electrode 30-plate electrode δ1, δ2 leaf surface potential difference

Claims (4)

[Claims] 1. A method for growing plants, which comprises irradiating a plant with artificial light to promote the growth of the plant, wherein a fluctuation component is added to the brightness of the artificial light. 2. A method for growing a plant, which comprises irradiating a plant with artificial light to promote the growth of the plant, wherein the artificial light is continuous light that is continuous in time series, and a fluctuation component is added to the brightness of the continuous light. A method for growing plants, characterized by: 3. A method for growing a plant, which comprises irradiating a plant with artificial light to promote the growth of the plant, wherein the artificial light is pulsed light that is intermittent in time series, and the period of the pulsed light and / or
Alternatively, a method for growing a plant is characterized by providing a fluctuation component to brightness. 4. A light emitting diode for irradiating a plant with artificial light, a drive means for supplying a drive current to the light emitting source, and a control means for giving a control signal for mixing a fluctuation component to the drive current to the drive means. A plant growing device characterized by being provided.