JP2006246798A6 - Plant cultivation method - Google Patents

Abstract

An object of the present invention is to provide a method for cultivating a plant that pays attention to the elements of red, blue, and yellow light, efficiently improves the lack of sunlight, extends the duration of sunlight, and promotes the growth of stems and roots.
The plant cultivation method of the present invention comprises auxiliary light sources 3 and 4 for irradiating a plant 8 and a sunlight intake window 1 which is provided above the plant 8 and takes in the sun. Is a large number of red LEDs 3 and blue LEDs 4. When the weather is clear, sunlight is applied to the plants, when it is cloudy, the red LED 3 is irradiated, and when it is raining, the red LED 3 and the blue LED 4 are irradiated. is there.
[Selection] Figure 11

Description

The present invention relates to a cultivation method for promoting the growth of plants, and relates to the provision of an optimal cultivation method for improving the lack of sunlight, extending the duration of sunlight, and promoting the growth of stems and roots.

Blue light-emitting diodes (blue LEDs) have been put into practical use, and methods for taking into account the elements of red, blue, and yellow light have been proposed for plant cultivation. In addition, a part of agricultural factory production has been started, and active research is being conducted for its practical use. As a result, it is known that red light greatly affects plant photosynthesis, blue light promotes flower bud formation and photosynthesis, and yellow light hardly contributes to plant growth. However, in reality, research has only just begun, and future research is expected.
Japanese Patent Laid-Open No. 2002-247919 JP 2002-272272 A

However, it can be said that research and application for red light and blue light are insufficient in the plant cultivation methods of Patent Documents 1 and 2 above. For example, Japanese Patent Laid-Open No. 2002-247919 examines the effects of red and blue light throughout the year on plant growth, but does not mention the effects of cloudiness or rain during the day. The effects of red and blue light are not taken into consideration. In addition, there is no mention of changes in red and blue light during the rainy season and autumn rain, and the effects of these changes on plant growth.
Japanese Patent Laid-Open No. 2002-272272 mentions that red light and blue light are related to plant photosynthesis and affects the growth of flower buds, but blue light is the growth of plant stems and roots. Is not described at all.
In addition, lettuce cultivation has been started in the factory, but only red LED lighting is used throughout the day. Since daytime sunlight is not used at all, energy use efficiency is poor.

  The present invention aims to provide a method for cultivating a plant that focuses on the elements of red, blue, and yellow light, efficiently improves the lack of sunlight, extends the duration of sunlight, and promotes the growth of stems and roots. To do.

When it is cloudy or raining, the sun is shining and daylight is weakened. It is preferable to detect the change in the amount of light at that time with a light amount sensor installed nearby. Here, the total light amount may be detected, or the red and blue light amounts may be detected. At this time, the shortage is compensated by controlling an auxiliary light source with many red and blue LEDs installed near the ceiling. Usually, when the clouds are coming out, the ratio of red light is reduced by about 20% (see FIG. 1), so the red LED is made to emit light to compensate for this shortage. Also, when the clouds are thick and raining, not only red light but also blue light is weakened. At that time, the red LED and the blue LED may also emit light.

The blue light mainly promotes root and stem growth. Therefore, when growing root vegetables such as radishes, carrots and burdocks, and when growing vegetables mainly made of stems such as asparagus, blue light is important. Therefore, as in the configuration of the present invention, the growth of roots and stems can be promoted by increasing the blue light, for example, by 10% to 20% by controlling the blue LED of the auxiliary light source. Blue light also promotes flower bud growth. In the case of a seed plant, a blue LED may be made to emit light after germination and after the time when the main leaves appear.

It can efficiently compensate for the lack of sunshine on cloudy and rainy days and provide efficient lighting in the morning and evening hours and at night, thus reducing power consumption and keeping plant cultivation costs low.

It is possible to provide lighting that promotes the growth of stems and roots when cultivating vegetables such as root vegetables and stalks, as well as potted flowers and foliage plants.

First, the results of examining the red, blue, and yellow light components in the day leading to the present invention will be described by Experiment 1.
(Experiment 1)

We investigated how the proportion of red, blue, and yellow light components changed with the weather, that is, the relative light intensity of red, blue, and yellow during sunny, cloudy, and rainy days. For example, FIG. 1 shows the relative light intensity examined over the time of one day on August 4, 2003. It was almost sunny all day, but the clouds came out from 11:00 to 12:30 and the sun was shaded. The ratio of red, blue, and yellow light intensity was almost constant outside this cloudy time, but the time when the cloud came out decreased by about 15% compared to when the ratio of red light was clear. The proportion of yellow light has increased. In addition, the ratio of blue light was almost unchanged throughout the day whether it was sunny or cloudy. This phenomenon can be explained as follows. Since red light has a long wavelength, the amount of red light absorbed by the cloud moisture increases. Therefore, the percentage of red light that reaches the ground decreases when clouds appear. On the other hand, since blue light has a short wavelength, the amount of scattering by the cloud increases, so when the cloud comes out, the blue light reaching the ground decreases slightly, but does not change significantly. On the other hand, since yellow light has a wavelength between red and blue and is not easily absorbed or scattered, the amount of light reaching the ground is almost the same regardless of whether it is clear or cloudy. That is, the proportion of yellow light increased because the amount of red light decreased and the amount of yellow light did not change.
In the evening, the sun's light is incident obliquely, so that the length of the light passing through the atmosphere increases, so that not only blue light but also yellow light is scattered and decreases. This increases the proportion of red light in the evening. This phenomenon is sunset. As can be seen from FIG. 1, this is why the yellow light is reduced around 18:00.
On the other hand, although the figure is omitted, the same result is obtained when it rains. When it rains and the clouds thicken, the percentage of red light that reaches the ground is reduced by about 20% compared to when it is clear.

From the results of Experiment 1, the following can be understood.
1) When a cloud of about cumulus clouds appears and the sun is shaded, the ratio of red light to the total amount of light is clear when the clouds appear (from 11 o'clock to 12:30) and clear (for example, from 8 o'clock) 1-15) is reduced by about 15 to 20%.
2) The percentage of yellow light increases by about 15% when clouds are seen compared to when it is clear.
3) In the evening and August, at around 18:00, the percentage of yellow light decreases compared to when it is sunny during the day.
Similarly, we examined when it rained. As a result, I found out the following.
4) The ratio of red light changes on sunny, cloudy and rainy days, and the red light decreases in the order of sunny>cloudy> rain.
5) The proportion of blue light remains almost unchanged throughout the day, whether it is sunny, cloudy or rainy.

Next, the results of examining the influence of red, blue, and yellow light on plant growth will be described by Experiment 2.
(Experiment 2)

We compared and observed the length and weight of stems and roots for the relationship between germination, growth process, and light of silk radish. I put the soil in the container, put water to cover the soil, and grown it for a week with natural light, red, blue, yellow light and no light on the seeds of kaiware radish from above The germination and growth of things were observed. Of these, those with poor growth were deleted. The results are shown in FIGS. FIG. 2 shows the observation results of the plants grown under natural light. The numbers in the figure are the numbers of silkworm radish individuals.

  FIG. 3 shows the observation results of the plants grown in a state where they were not exposed to light. As can be seen from the average value of the stem length, when grown without light, the stem was about twice as long as that grown with natural light (see FIG. 2). On the other hand, the average value of the total weight was the same, but the weight of the stem was about twice that of natural light, the leaves were small and the weight was half that of natural light.

  FIG. 4 is an observation result of the growth of the blue light and the yellow light with the transmittance of red light being reduced to about one-fourth while maintaining the red light transmittance. As can be seen from the average value of the stem length, when grown under this condition, the stem length was about 1.5 times that of the plant grown under natural light (FIG. 2).

  FIG. 5 is an observation result of a plant grown with almost no blue and yellow light passing therethrough. As can be seen from the average values of stem length and stem weight, when grown under this condition, the stem is about 1.5 times longer than that grown under natural light (Figure 2). Has doubled in weight. In other words, you can see that the stems are thicker than those grown in natural light.

  FIG. 6 is an observation result of growing with the transmittance of red and yellow dropped to about one third while maintaining the transmittance of blue light. As you can see from the average values of root length and root weight, the root length is almost the same as that grown under natural light (Fig. 2). Now weighed 1.3 times. In other words, it can be seen that when grown under this condition, the roots are 1.3 times thicker than when grown under natural light.

  FIG. 7 is an observation result of the growth of the red and yellow light transmittances reduced to about 1/6 while maintaining the blue light transmittance. As you can see from the average values of root length and root weight, the root length is almost the same as that grown under this condition (Fig. 2). The weight has increased 1.5 times. In other words, it can be seen that growing under this condition doubles the roots compared to growing under natural light.

  FIG. 8 shows the observation results of the growth of yellow and light with the transmittance of red and blue light being reduced to about 1/6. As you can see from the average length and weight of the stems, the length and weight of the roots, and the weight of the leaves, what length compared to those grown under natural light (Fig. 2) The weight is almost the same.

FIG. 9 shows the results of observation of a plant grown with almost no red and blue light. As can be seen from the average value of the weight of the leaves, when grown under this condition, the weight of the leaves was about 0.6 times that of the one grown under natural light (Fig. 2). In addition, the length and weight of stems and roots are almost the same.

The results are summarized as shown in FIG.
The stems grow longer when grown in a dark room. When grown in blue light, the ratio of root to stem length is about the same as that grown in natural light. On the other hand, the ratio of the length of the roots and stems of those grown in a dark room and those exposed to red or yellow light is about half that of those grown in natural light. In other words, it is clear that the blue light promotes root growth. Those grown under natural light have shorter stems than other conditions. In other words, changing the light balance shows that the stem becomes longer. Next, I checked the weight. Growing under blue light, the weight per unit length of the stem is about 1.5 times that grown in natural light. In addition, when grown in blue light, the weight per unit length of the roots is about twice that grown under other conditions. In other words, the blue light has the effect of growing and thickening the stem and root. Leaves grow red when exposed to red light. This is because red light promotes leaf growth and acts on chlorophyll.

The results of Experiment 2 are summarized as follows.
1) Red light grows leaves and stems, creates chlorophyll and acts on photosynthesis.
2) Blue light thickens roots and stems. In particular, make the roots thicker and increase the side roots.
3) Yellow light does not affect plant growth.
4) Changing the balance of natural light color will lengthen the stem.

  Growing under red light encourages the growth of stems and leaves, so it is better to grow them against leafy vegetables such as lettuce. Growing under red and blue light makes the roots and stems thick, so it is best to apply them to root vegetables such as radishes and carrots and vegetables that eat mainly stems such as asparagus. In addition, since the growth of roots and stems is also important for the growth of potted flowers and foliage plants, it is important to apply red light and blue light.

Next, specific examples will be described. FIG. 11 shows an embodiment of the present invention in an agricultural factory. A ceiling 2 of an agricultural factory (same as a greenhouse) has a window 1 for taking in sunlight 7, and an auxiliary light source in which a large number of LEDs 3 and 4 are arranged is arranged near the ceiling. The multiple LEDs are composed of two types of LEDs, a red LED 3 and a blue LED 4. Further, a plant 8 to be grown is planted, and a light amount sensor 6 for detecting the light amount is provided in the vicinity thereof. The light emission intensity of the LEDs 3 and 4 is controlled by the LED light emission control circuit 5 so that the light amounts of the LEDs 3 and 4 can be changed according to the output of the light quantity sensor 6.

When the sky is cloudy or it rains, red light is reduced, so the light quantity sensor 6 detects the total light quantity or the red and blue light quantities. The light quantity of the red LED 3 and the blue LED 4 is controlled according to the output of the light quantity sensor. In addition, by taking in sunlight 7 during the day and turning on the LEDs 3 and 4 from evening to night, the growing period of the plant can be shortened and harvested quickly, and the power consumption can be measured.
In addition, the window 1 for taking in the sunlight 7 is a window 1 for taking in the sunlight 7 directly, or in a configuration in which the sunlight 7 is guided by an optical fiber, the sunlight 7 is guided by an end face of the optical fiber or a mirror. Then, the mirror arranged last may be used. Thereby, it can respond also to the factory of a multi-story floor.

It is used to grow root vegetables such as radishes and carrots, vegetables mainly made of stems such as asparagus, potted flowers and foliage plants in agricultural factories and greenhouses. This is an auxiliary light source for days when it is cloudy or rainy, or a plant cultivation method that is used for early harvesting of vegetables by extending sunshine hours in the evening or at night.

It is a graph which shows the relative light intensity of red, blue, and yellow at the time of the day. It is the figure which showed the result of having compared the length and the weight of a stem and a root when germinating and growing in a golden radish, when it grew up on natural light. It is the figure which showed the result of having compared the length and the weight of a stem and a root when it grows in the state which did not shine in the germination and growth of a silk radish. Shows the results of comparing the length and weight of stems and roots when growing with the light transmittance of blue and yellow being reduced to about one-quarter while keeping the red light transmittance in germination and growth of silkworm radish. It is a figure. It is the figure which showed the result of having compared the length and the weight of a stem and a root when germinating and growing of silkworm radish, when it grew without passing blue and yellow light almost. The results showed a comparison of stem and root lengths and weights when the red and yellow transmittances were reduced to about one third while keeping the blue light transmittance in germination and growth of silkworm radish. FIG. Shows the results of comparing the length and weight of stems and roots when growing with red light and yellow light transmittances reduced to about 1/6 while germination and growth of silkworm radish is unchanged. It is a figure. Shows the results of comparing the length and weight of stems and roots when growing with the transmittance of yellow and red light being reduced to about one-sixth of the yellow radish germination and growth. It is a figure. It is the figure which showed the result of having compared the length and the weight of a stem and a root when germination and growth of a golden radish were raised without passing light of red and blue almost. It is a table that summarizes the results of comparing the length and weight of stems and roots for the seedlings and the growth process of the golden radish, those that were exposed to natural light, red, blue, and yellow light, and those that were grown in a dark room. . It is an Example of this invention in an agricultural factory.

Explanation of symbols

1. Sunlight intake window
2. Ceiling 3. Red LED
4). Blue LED
5. LED light emission control circuit 6. 6. Light quantity sensor Sunlight8. plant

Claims (5)

It consists of an auxiliary light source that irradiates the plant and a sunlight intake window that is installed above the plant and takes in the sun.The auxiliary light source is composed of a large number of red LEDs and blue LEDs. A plant cultivation method characterized by irradiating the plant with sunlight, irradiating the red LED when cloudy, and irradiating the red LED and blue LED when raining. In the vicinity of the plant, there is a light amount sensor that measures the amount of light hitting the plant, and an LED light emission control circuit that controls the amount of light emitted from the auxiliary light source so as to maintain the amount of light hitting the plant according to the output of the light amount sensor The plant cultivation method according to claim 1, wherein the plant cultivation method is provided. The window for taking in sunlight is a window for taking in sunlight directly, or an end face of an optical fiber in a configuration in which sunlight is guided by an optical fiber, or a mirror disposed last in a configuration in which sunlight is guided by a mirror. The plant cultivation method according to claim 1, wherein the plant cultivation method is provided.   3. The plant cultivation method according to claim 1, wherein after the germination of the plant, the plant is irradiated with a blue LED after a time when a main leaf comes out. When the plant is a root vegetable mainly composed of roots such as radishes and carrots, or a vegetable mainly composed of stems such as asparagus, it is allowed to grow by emitting both the red LED and the blue LED. A plant cultivation method characterized.

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