JP7172235B2 - Plant growth method and plant growth system - Google Patents

Description

TECHNICAL FIELD The present invention relates to a plant growing method and a plant growing system for growing plants such as vegetables whose above-ground parts other than root vegetables are edible.

Functional vegetables with increased components contained in vegetables are being studied (see, for example, Patent Document 1). This document describes a method for producing functional vegetables in which the fortifying components of vegetables are increased by immersing the vegetables in a solution containing the fortifying components to be increased in the vegetables for a certain period of time or more before harvesting.

JP 2017-200448 A

In the documents mentioned above, it was necessary to prepare a solution in which the vegetables were soaked before harvesting, separately from the culture solution normally supplied to the vegetables. For this reason, cultivation management was time-consuming. In addition, when switching the culture solution or solution, the plant may be damaged and wilt.

A plant growing method for solving the above-mentioned problems strengthens the lutein concentration and sugar content in the edible part while supplying the root of the plant whose edible part is the above-ground part with a culture solution containing iron content to be increased in the above-mentioned above-ground part. A plant growing method for growing the plant in such a manner that , after planting at the time when the two leaves of the plant are fully grown, a stable growth period is obtained by confirming the state that a plurality of true leaves of the plant are fully grown. After the determination , the plant is grown by promoting transpiration of the plant while supplying the culture solution to the plant in a state in which only the tips of the roots are in contact with the culture solution .

A plant growth system that solves the above problems strengthens the lutein concentration and sugar content in the edible part while supplying the root of the plant whose edible part is the above-ground part with a culture solution containing iron content that is increased in the above-ground part. A control system for determining the growth state of the plant from the number of the true leaves of the plant, which is connected to a camera for photographing the plant, and which is periodically photographed; A culture solution supply unit that adjusts the amount of culture solution supplied, and a humidity adjustment unit that adjusts the humidity of the space in which the plant is arranged based on transpiration control that adjusts the humidity to promote transpiration of the plant. , the control system determines that the plant is in a stable growth period by confirming that a plurality of true leaves have grown in the photographed plant, and after it is determined to be the stable growth period, the culture solution supply unit, The supply amount of the culture solution is controlled so that only the tips of the roots are brought into contact with the culture solution, and the humidity adjusting section controls the humidity to promote transpiration of the plant.

ADVANTAGE OF THE INVENTION According to this invention, the plant which increased the reinforcement|strengthening component in the edible part can be grown efficiently.

BRIEF DESCRIPTION OF THE DRAWINGS The schematic block diagram of the plant growth system in embodiment. Explanatory drawing explaining the plant growth method in embodiment. BRIEF DESCRIPTION OF THE DRAWINGS It is explanatory drawing of the amount of substance contained in the plant actually grown using the plant growth method of embodiment, Comprising: (a) is a lutein concentration, (b) is a sugar content, (c) shows a SPAD value.

An embodiment embodying a plant growing method and a plant growing system will be described below with reference to FIGS. 1 to 3. FIG. In the present embodiment, it is assumed that spinach is grown as a plant whose edible part is above the ground.

First, a plant cultivation facility 10 as a plant growth system will be described with reference to FIG.
The plant cultivation facility 10 is isolated from the outside world, and is configured as a closed space that can be entered and exited when a side door is opened.

A plant cultivation facility 10 is provided with a cultivation bed 20 planted with spinach Lg. A plurality of light sources 11 are arranged above the cultivation bed 20 . The light source 11 is an artificial light illumination device that irradiates the spinach Lg with artificial light as sunshine. The light source 11 is a light source capable of adjusting the amount of light quanta, and can use a fluorescent lamp or a fluorescent lamp-type LED (light emitting diode). Moreover, in this embodiment, it is exposed to sunlight from 8:00 to 24:00 every day (light period is 16 hours).

The plant cultivation facility 10 is provided with a temperature detection unit 13 and a room temperature adjustment device 14 . The room temperature adjustment device 14 acquires the room temperature (room temperature) inside the plant cultivation facility 10 detected by the temperature detection unit 13, and adjusts the inside of the plant cultivation facility 10 to the set temperature. In this embodiment, the room temperature is set to 25°C.

In addition, the plant cultivation facility 10 is provided with a humidity detection unit 15 and a humidity adjustment device 16 as a humidity adjustment unit. The humidity adjustment device 16 acquires the humidity inside the plant cultivation facility 10 detected by the humidity detection unit 15, and adjusts the inside of the plant cultivation facility 10 to the set humidity.

Furthermore, the plant cultivation facility 10 is provided with a gas concentration detection unit (not shown) and a carbon dioxide supply unit (not shown). The carbon dioxide gas supply unit detects the carbon dioxide (CO2) concentration in the plant cultivation facility 10 detected by the gas concentration detection unit in the light period after the leaves of the spinach Lg grow, and the office with a high CO2 concentration (Fig. (not shown) is supplied to the room.

The cultivation bed 20 includes a retention section 21 that retains the circulated culture solution. The retention portion 21 is connected to the storage portion 22 via a supply pipe 23a and a discharge pipe 23b. A supply pump (not shown) and a discharge pump (not shown) are provided for the supply pipe 23a and the discharge pipe 23b. The retention part 21, the storage part 22, the supply pipe 23a, the discharge pipe 23b, the supply pump, and the discharge pump constitute a culture fluid supply part. The culture solution in the storage section 22 is supplied to the retention section 21 through the supply pipe 23a and discharged from the retention section 21 through the discharge pipe 23b. In this embodiment, the culture solution flows through the retention section 21 at a flow rate of 5 liters per minute.

The storage part 22 accumulates the culture medium that has been recirculated through the retention part 21 . The culture solution used in the present embodiment is a culture solution to which bivalent iron is added in order to enrich the spinach with iron. The storage section 22 includes a nutrient detection section and a concentration adjustment section. The concentration adjustment unit detects the nutrient concentration (fertilizer concentration) detected by the nutrient detection unit, and adds necessary nutrients to the culture solution according to the set concentration of each component.

<Composition of cultivation bed>
Next, details of the cultivation bed 20 will be described.
A plurality of mounting tables 24 are accommodated in the retention portion 21 of the cultivation bed 20 . A culture medium container 25 is fixed on the mounting table 24 . The culture medium container 25 has a box shape with an open top. A large number of through-holes 25 a are formed in the side and bottom surfaces of the culture medium containing portion 25 . The upper end portion of the culture medium containing portion 25 is lower than the upper end portion of the retaining portion 21 , and the culture medium containing portion 25 is configured to be included in the retaining portion 21 .

A water-permeable sheet 26 is laid on the inner bottom surface, the inner side surface, and the outer side surface of the culture medium storage section 25 so as to extend over them. The outer end of the water-permeable sheet 26 extends to a position lower than the bottom surface of the medium containing section 25 . Furthermore, the inner bottom surface and the inner side surface of the water-permeable sheet 26 are covered with a water-permeable nonwoven fabric 27 .
Furthermore, a plate-shaped culture medium C1 is arranged on the upper surface of the culture medium storage section 25 . This medium C1 is made of synthetic resin such as plastic, and is planted with a plurality of spinach Lg.

<Plant growth method>
Next, a method for growing spinach Lg using the plant cultivation facility 10 described above will be described with reference to FIG.

As shown in FIG. 2, seeding is first performed. Then, seeds of spinach Lg are planted on the medium C1.
And it grows without water stress. Specifically, the retention portion 21 is filled with the culture solution to a height (the height of the culture medium C1 in the retention portion 21) at which water can be supplied to the seeds without causing the seeds to flow. Then, while maintaining the liquid surface at this height, the culture solution is circulated to grow the spinach Lg. In this case, the humidity inside the plant cultivation facility 10 is set to 45% to 50%.

After 2 to 3 weeks have passed and germination has occurred, the seedlings are planted. Here, planting is performed when the spinach Lg has two leaves.
A little less than 2 to 3 weeks after planting, spinach Lg enters a stable growth stage. In the present embodiment, the stable growth stage is determined by confirming that a plurality of (for example, two) true leaves have grown. In this case, it is confirmed that at least part of the roots R1 of the spinach Lg planted in the culture medium C1 are in contact with the nonwoven fabric 27 on the inner bottom surface of the culture medium storage section 25 .

When it is determined that the growth is stable, the water level of the culture solution in the retention section 21 of the cultivation bed 20 is lowered (water stress control). Specifically, the culture solution on the cultivation bed 20 is discharged, and the liquid level of the culture solution at the height of the medium C1 is lowered to the height of the inner bottom surface of the medium container 25 as shown in FIG. As a result, only the tips of the roots R1 of the spinach Lg are brought into contact with the culture medium via the nonwoven fabric 27 on the water permeable sheet 26 . In this case, the water and nutrients of the culture solution are obtained only from the tips of the roots R1 in contact with the nonwoven fabric 27, and water stress is applied to the spinach Lg.

Furthermore, at the same time, the humidity in the plant cultivation facility 10 is set to a humidity that promotes the transpiration of the spinach Lg (transpiration control). Here, the humidity that promotes transpiration of the spinach Lg is set to 70% to 85%. In this case, the spinach Lg absorbs more water and nutrients from the culture solution from the root R1 to the above ground part in order to promote the release of water vapor from the leaves of the spinach Lg.

Then, it grows for 10 to 11 days under environmental control of this transpiration and water stress. During this growth, the water level of the cultivation bed 20 is maintained so that the permeable sheet 26 does not dry out.
After that, the spinach Lg is harvested.

<Actual experimental value>
Spinach Lg was actually grown three times by the plant growth method described above. The cultivar Green Spinach (GS) was used for the first and second runs, and the cultivar Summer Sky (SS) was used for the third run. Moreover, each time, the plants were grown simultaneously under the condition that two light sources, a fluorescent lamp and an LED (M6W), were separately used. However, for the first time, the photon flux density (PFD) was 150 (μmol·m ^-2 ·s ^-1 ), and for the second and third times, the PFD was 170 (μmol · m ^-2 · s ^-1 ). ). The number of days elapsed in each step is shown in Table 1 below.

なお、上述した水ストレスを与えた生育方法と比較するために、各回とも、通常の方法（無処理）によってもホウレン草を生育した。

In addition, in order to compare with the above-mentioned growing method in which water stress was applied, spinach was also grown by a normal method (no treatment) each time.

FIG. 3 shows the amounts of substances contained in the spinach harvested each time.
FIG. 3(a) shows the average lutein concentration, FIG. 3(b) shows the average sugar content, and FIG. 3(c) shows the average SPAD value (chlorophyll meter value). The sugar content and SPAD values in FIGS. 3(b) and 3(c) also show fluctuations. From the amounts of substances shown in FIG. 3, the spinach grown by the method of the present embodiment had higher lutein concentration, sugar content and SPAD value than the spinach grown by the normal method.

According to this embodiment, the following effects can be obtained.
(1) In the present embodiment, spinach Lg is grown by promoting transpiration while applying water stress. As a result, components contained in the culture solution are easily sucked up from the roots R1 of the spinach Lg to the edible part on the ground, so that the edible part can be increased in the reinforcing component. Moreover, in this case, since the culture solution given to the spinach Lg is not changed, management can be simplified.

(2) In the present embodiment, spinach Lg is given water stress after the stable growth period. As a result, since water stress is not applied during the period when damage is less likely to occur, wilting due to water stress can be reduced.

(3) In the present embodiment, when a plurality of true leaves of the spinach Lg are fully grown, it is determined that the growth stage is stable. This makes it possible to easily determine the timing of applying water stress.

(4) In the present embodiment, the humidity in the plant cultivation facility 10 is set at 70% to 85% to promote transpiration of the spinach Lg. Thereby, the transpiration of the spinach Lg can be efficiently promoted.

(5) In the present embodiment, a box-shaped medium container 25 with an open top is fixed in the cultivation bed 20, and the medium C1 planted with spinach Lg is placed on the medium container 25. As a result, only by lowering the water level of the culture solution in the stagnant part 21 of the cultivation bed 20, the culture solution can be supplied only to the tips of the roots R1 of the spinach Lg, and water stress can be applied to the spinach Lg.

(6) In the present embodiment, the outer end of the permeable sheet 26 laid on the inner bottom surface of the culture medium containing section 25 extends to a position lower than the bottom surface of the culture medium containing section 25 in the retention section 21 . The water level of the cultivation bed 20 is maintained so that the water-permeable sheet 26 does not dry out while the spinach Lg is under water stress. As a result, even if the water level in the retention section 21 fluctuates to some extent due to the circulation of the culture solution, the culture solution can be supplied to the spinach Lg while applying water stress.

This embodiment can be implemented with the following modifications. This embodiment and the following modified examples can be implemented in combination with each other within a technically consistent range.
- In the above embodiment, spinach Lg was subjected to water stress. The stress given to plants is not limited to this. For example, environmental stress such as salt stress that can be continuously applied to plants over a long period of time (several days or more) may be used.

- In the above embodiment, after a little less than 2 to 3 weeks, the number of true leaves of the spinach Lg was used to determine whether or not the growth stage was stable. The determination of whether or not the plant to start stressing is in the stable growth stage may be made from other than the number of true leaves. For example, whether or not the plant is in the stable growth period may be determined based on the length of the roots of the plant, the growth rate of the leaves, or the like. Further, image processing may be used to determine the stable growth period. In this case, a camera for photographing the spinach Lg is installed and connected to the control system. Then, the control system periodically photographs the spinach Lg with a camera to determine the growth state. For this determination, image recognition based on machine learning can be used for the number of true leaves and the state of roots R1 of spinach Lg. Then, when it is determined to be in the stable period, the control system performs stress control (supply amount control of culture solution) and transpiration control (humidity control).

- In the above-described embodiment, in order to apply water stress to the spinach Lg, the liquid level of the culture solution is lowered to the inner bottom surface of the medium container 25 on which the water-permeable sheet 26 and the nonwoven fabric 27 are laid. The configuration of the plant growth system that gives water stress is not limited to this. For example, a general NFT (nutrient film technique: thin film hydroponics) structure with an inclined liquid surface may be used. In addition, the culture medium C1 in which plants that were normally cultivated before water stress are planted may be moved to the cultivation bed 20 described above when water stress is applied.

- In the above-described embodiment, transpiration is promoted by setting the humidity in the plant cultivation facility 10 in which the spinach Lg is arranged. The transpiration control method for promoting transpiration of growing plants is not limited to the humidity setting in the room where the plants are placed. For example, a sensor may be used to measure the transpiration status of plant leaves, and the humidity may be adjusted according to the transpiration status so that transpiration is promoted. In this case, the humidity is adjusted so that the value measured by the sensor that measures the state of transpiration is greater than or equal to the reference value. Transpiration control may also be performed by controlling humidity and temperature.

- In the above embodiment, spinach Lg with increased iron content was grown as a plant. Plants that grow are not limited to spinach. For example, leafy vegetables such as lettuce and cabbage absorb the components contained in the culture solution from the roots, and the above-ground parts that are translocated from the roots to the leaves and fruits of the plants are edible. It can be applied to any plant that is part of the plant. Ingredients to be increased in vegetables are not limited to iron, and may be other nutritional ingredients such as vitamins. In this case, a culture medium to which a plant-enhancing component has been added is used.

C1... Medium, Lg... Spinach, R1... Root, 10... Plant cultivation facility, 11... Light source, 13... Temperature detector, 14... Room temperature adjuster, 15... Humidity detector, 16... Humidity adjuster, 20... Cultivation bed , 21... retention part, 22... storage part, 23a... supply pipe, 23b... discharge pipe, 24... mounting table, 25... culture medium accommodating part, 25a... through hole, 26... water-permeable sheet, 27... nonwoven fabric.

Claims (3)

Plant growth of growing the plant so as to enhance the lutein concentration and sugar content in the edible part while supplying the root of the plant whose edible part is the above ground part with a culture solution containing iron content to be increased in the above ground part. a method,
After planting at the time when the two leaves of the plant are all grown, after it is determined that the growth is stable by confirming the state that a plurality of true leaves of the plant are all grown, only the tip of the root is cultured. A plant growing method for growing the plant by promoting transpiration of the plant while supplying the culture solution to the plant in contact with the liquid . 2. The plant growing method according to claim 1 , wherein the promotion of transpiration of the plant is performed by adjusting the humidity of the space in which the plant is placed. Plant growth of growing the plant so as to enhance the lutein concentration and sugar content in the edible part while supplying the root of the plant whose edible part is the above ground part with a culture solution containing iron content to be increased in the above ground part. a system,
a control system connected to a camera for photographing the plant and determining the growth state of the plant from the number of the plant true leaves photographed periodically;
a culture solution supply unit that adjusts the supply amount of the culture solution;
A humidity adjustment unit that adjusts the humidity of the space in which the plant is arranged based on the transpiration control that adjusts the humidity to promote the transpiration of the plant ,
The control system is
Judging that the plant is in a stable growth stage by confirming that a plurality of true leaves have grown in the photographed plant,
After the stable growth period is determined, the culture solution supply unit controls the supply amount of the culture solution so that only the tips of the roots are in contact with the culture solution, and A plant growth system characterized by controlling humidity to promote transpiration of the plant by a humidity control unit .

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