JP7276907B2 - Panax ginseng hydroponics method - Google Patents

Description

TECHNICAL FIELD The present invention relates to a method for hydroponic cultivation of Panax ginseng and a nutrient solution for hydroponic cultivation.

Panax ginseng, which is a perennial plant belonging to the family Araliaceae, is also called ginseng or Korean ginseng, and has been used medicinally since ancient times because it contains ginsenosides having a nourishing and tonic effect.

Traditionally, panax ginseng has been cultivated outdoors, but it is slow to grow and takes four to six years from sowing to harvest. It has to be maintained and is time consuming. In addition, since Panax ginseng causes severe damage to continuous cropping, it is necessary to leave an interval of 10 years or more after harvesting Panax ginseng before the next planting, and the utilization efficiency of the cultivation soil is poor.

Furthermore, Panax ginseng is susceptible to disease caused by mold (fungi) and feeding damage by pests, and it is necessary to disinfect the soil and spray fungicides and insecticides in order to prevent or suppress the occurrence of disease and feeding damage. Therefore, in order to use the harvested Panax ginseng as a crude drug or to extract a medicinal component from Panax ginseng, disinfectants, fungicides, insecticides, etc. attached to Panax ginseng during open field cultivation must be thoroughly washed away.

As described above, open-field cultivation of Panax ginseng is troublesome and costly, so hydroponic cultivation of Panax ginseng has been studied. However, most of the hydroponic cultivation methods commonly used in the past aim to speed up the growth of plants such as leafy vegetables, tomatoes, and strawberries that harvest the above-ground parts that are not immersed in the nutrient solution. Even if the conventional method is applied to hydroponics of Panax ginseng, it is difficult to enlarge the root part.

Since a large amount of oxygen is required for the growth of roots, root vegetables such as radishes, burdocks, and carrots are usually immersed in the nutrient solution by periodically draining the nutrient solution from the cultivation container. There is known a method of performing a process called aeration in which roots in a state of being exposed to the air are exposed to the air, or air is sent to the roots exposed to the air (Patent Document 1). Therefore, a method has been proposed in which a method of aeration is adopted in hydroponics of Panax ginseng (Patent Document 2).

JP 2012-100573 A JP 2016-34243 A

In the case of Panax ginseng, it is required not only to enlarge the underground part but also to increase the content of ginsenosides, which are medicinal ingredients contained in the underground part. The biosynthesis of ginsenosides requires components contained in the nutrient solution, but the components in the nutrient solution are not absorbed by the roots during aeration. Therefore, the method of Patent Document 2 has a problem that the medicinal component cannot be obtained in an amount corresponding to the enlargement of the underground part of Panax ginseng.

The problem to be solved by the present invention is to provide a hydroponics method and a nutrient solution for hydroponic cultivation that can achieve both enlargement of the underground part of Panax ginseng and an increase in the amount of medicinal components.

The hydroponics method for panax ginseng according to the present invention, which has been made to solve the above problems,
At least during the period from sowing to harvesting, the growth period is a period in which seedlings whose underground parts have grown to a predetermined size are cultivated until they are harvested. Cultivation of panax ginseng using a nutrient solution containing fertilizer components necessary for the growth of the underground part in a light-dark cycle that alternately repeats a dark period in which the above-ground part is irradiated with a lower amount of light than the light period. A method for hydroponic cultivation of Panax ginseng,
A first state in which 80% or more of the underground portion is immersed in the nutrient solution and a second state in which more than half of the underground portion is exposed to the air during one light-dark cycle during the growth period. is performed at least once in which the liquid level of the nutrient solution is moved up and down so as to alternately repeat The immersion treatment step is performed to maintain a height such that 80% or more of the nutrient solution is immersed in the nutrient solution.

In the hydroponic method of the present invention, the seedling whose underground part has grown to a predetermined size refers to a seedling whose underground part has reached about 80% to about the same length as the harvested Panax ginseng. , Such seedlings can be obtained about 2 to 3 years after germination. This seedling enlarges in the underground part by subsequent cultivation, that is, cultivation during the growth period. Therefore, cultivation during the growing season is mainly aimed at enlarging the underground part. By adopting hydroponics for the cultivation of Panax ginseng during the growth period, the underground part can be enlarged quickly.

In the hydroponics method of the present invention, "one light-dark cycle" is generally 24 hours, but may be shorter or longer than 24 hours. For example, when the light period is 12 hours and the dark period is 12 hours, one light-dark cycle is 24 hours, and when the light period is 10 hours and the dark period is 10 hours, one light-dark cycle is 20 hours. Also, the light period and the dark period may not be the same time. For example, when the light period is 12 hours and the dark period is 13 hours, one light-dark cycle is 25 hours.

In the nutrient solution cultivation method of the present invention, in the immersion treatment step, 80% or more of the underground part of Panax ginseng is immersed in the nutrient solution, and the components contained in the nutrient solution are continuously absorbed into the underground part. Therefore, the biosynthesis of medicinal components in the cells of Panax ginseng proceeds stably and efficiently. On the other hand, in the aeration process, the first state and the second state are alternately repeated, and in the second state, half or more of the underground part is exposed to the air, so that a large amount of oxygen is taken into the underground part, and the underground part is removed. Hypertrophy progresses.

In the second state of the aeration process, the subterranean part is exposed to the air, supplying a large amount of oxygen to the subterranean part, but drying the subterranean part. If the underground portion is exposed to the air for a long time, the underground portion will be dried and damaged.

Further, the nutrient solution for hydroponic cultivation according to the present invention is used in the above-described hydroponic cultivation method for Panax ginseng, and has a concentration of magnesium ions in the range of 40 ppm to 56 ppm (preferably 48 ppm), and zinc ions is in the range of 10 to 26 ppm (preferably 18 ppm).

In the present invention, hydroponics is performed at least during the growing period of Panax ginseng, during which the aeration step is performed at least once during one light-dark cycle, and the immersion treatment step is performed during the rest of the growing period. In the aeration process, since a large amount of oxygen is supplied to the underground portion in the second state, the enlargement of the underground portion progresses, but the amount of absorption of the components in the nutrient solution in the underground portion decreases accordingly. On the other hand, in the immersion treatment process, the components in the nutrient solution are continuously absorbed into the underground part, and the biosynthesis of the medicinal components in the underground part is stably and efficiently performed. In other words, in the present invention, the amount of biosynthesis of medicinal ingredients in the underground part that is reduced by the aeration process is compensated for by the soaking treatment process, so both the enlargement of the underground part of Panax ginseng and the increase in the amount of medicinal ingredients are achieved. can do.

BRIEF DESCRIPTION OF THE DRAWINGS The schematic which shows one Example of the hydroponic apparatus used for the hydroponic cultivation method which concerns on this invention. Sectional drawing of a cultivation pot. A photograph of the aerial part of Panax ginseng hydroponically cultivated with the Otsuka A formula nutrient solution. Photographs of the underground part (right side) of panax ginseng hydroponic cultured for 3 months in a high Mg-Zn nutrient solution and the underground part (left side) of panax ginseng cultivated outdoors for 2 years. Graph showing the relationship between the light intensity and the content of the medicinal ingredient. The graph which compared the fresh weight of the seedling which carried out hydroponic cultivation of the open field biennial seedling for 3 months, and the open field biennial seedling. A photograph showing the results of iodine treatment of the underground part of seedlings that had been subjected to hydroponic culture for 3 months. Concentration of macroelements contained in the subterranean part of seedlings cultivated with hydroponic culture for 3 months. Concentration of trace elements contained in the subterranean part of seedlings cultivated by hydroponics for 3 months. Graph comparing amounts of medicinal components contained in seedlings cultured for 3 months in open field biennial seedlings in high Mg-Zn nutrient solution and Otsuka A prescription nutrient solution, respectively. FIG. 10 is a schematic diagram of a hydroponic cultivation apparatus used in the hydroponic cultivation method of Example 3 of the present invention, showing a state during a seedling-raising period; Schematic diagram of the hydroponics apparatus during the growth period.

The method for hydroponic cultivation of Panax ginseng according to the present invention is used for cultivating Panax ginseng during the growing period, which is the period from sowing to harvesting, at least during which seedlings whose underground parts have grown to a predetermined size are cultivated until harvesting. be done. In the hydroponic cultivation method of the present invention, a first state in which the underground portion is immersed in the nutrient solution and a second state in which the underground portion is exposed to the air are alternated during one light-dark cycle. The aeration step of repeatedly raising and lowering the level of the nutrient solution is performed at least once, and during the remaining time, the level of the nutrient solution is maintained at a height such that the underground portion is immersed in the nutrient solution. It is characterized by performing an immersion treatment process to.

In the first state of the aeration step, which is the immersion treatment step, it is preferable that the entire underground portion is immersed in the nutrient solution in order to allow the underground portion to absorb more of the fertilizer components in the nutrient solution. If 80% or more of the underground part is immersed in the nutrient solution, the necessary amount of fertilizer components can be absorbed from the underground part.

In the second state of the aeration step, it is preferable to expose the entire underground portion to the air in order to take in more oxygen from the underground portion. A sufficient amount of oxygen can be taken up from the subterranean part for the enlargement of the part. In particular, if the second state is maintained for a long time, the drying of the underground portion progresses accordingly, so it is preferable to immerse a part of the underground portion in the nutrient solution. In particular, the lower part of the underground part is thinner than the upper part and is easily damaged by drying, so it is preferable to immerse it in the nutrient solution.

If the underground portion is exposed to the air for a long time, the underground portion will be dried and damaged. In such a time range, a large amount of oxygen can be taken in from the underground part without the underground part being damaged.

It is preferable that the immersion treatment process and the aeration process are alternately performed in a cycle of 3 hours to 12 hours. Alternating in a cycle of 3 hours means that the immersion treatment step and the aeration step are alternately performed for 3 hours each, and when one light/dark cycle is 24 hours, the immersion treatment step and the aeration step are performed in one light/dark cycle. Each aeration process is performed four times. By setting such a cycle, the fertilizer component in the nutrient solution taken into the underground part in the immersion treatment process is stably and efficiently used for the biosynthesis of the medicinal component, while in the aeration process It can take in a large amount of oxygen and promote enlargement of the underground part.

Magnesium (Mg ²⁺ ) and zinc (Zn ²⁺ ) are examples of fertilizer components that contribute to the biosynthesis of medicinal components of Panax ginseng. It is better to increase the amount of magnesium and zinc than the prescription of the nutrient solution.

Hereinafter, the hydroponics method according to the present invention will be described with reference to specific examples.
[Example 1]
In this embodiment, during the germination period, which is the cultivation period from sowing to germination, and the seedling-raising period, which is the cultivation period from germination until the underground part grows to a predetermined size, Panax ginseng is cultivated in the open field, and in the subsequent cultivation period. Hydroponic cultivation was performed during a certain growth period, and cultivation conditions for hydroponic cultivation were examined.

(1) Hydroponic Cultivation Apparatus FIG. 1 shows a schematic diagram of the hydroponic apparatus used in this example. A nutrient solution cultivation apparatus 100 includes a mounting table 10, a plurality of cultivation pots 11 placed on the mounting table 10, a nutrient solution tank 12 disposed below the mounting table 10, and a nutrient solution stored in the nutrient solution tank 12. A liquid feed pipe 13 for feeding the nutrient solution into the cultivation pot 11 , a liquid feed pump 14 arranged at the bottom of the mounting table 10 , and a plurality of supports 16 to the top of the mounting table 10 . A ceiling portion 17 is arranged, and LEDs 18 and a plurality of water supply pipes 19, which are a plurality of lighting fixtures attached to the lower surface of the ceiling portion 17, are provided. One end of the liquid supply pipe 13 is connected to the nutrient solution tank 12 , extends from there along the mounting table 10 and the support 16 to the ceiling portion 17 , and is connected to the water supply pipe 19 at the ceiling portion 17 . A liquid-sending pump 14 is connected to the middle of the liquid-sending pipe 13 positioned below the mounting table 10 .

The liquid-sending pump 14 supplies the nutrient solution in the nutrient solution tank 12 to the water supply pipe 19 through the liquid-sending pipe 13 . The number of water supply pipes 19 and cultivation pots 11 are the same, and the lower ends of the water supply pipes 19 are located near the upper openings of the cultivation pots 11 . The nutrient solution that has flowed to the water supply pipe 19 is supplied into each cultivation pot 11 . The LED 18 and liquid transfer pump 14 are controlled by the controller 20 .

FIG. 2 is a schematic enlarged view of the cultivation pot 11. FIG. The cultivation pot 11 includes a cylindrical member 111, porous disc-shaped members 112 and 113 fitted in the upper and lower portions of the cylindrical member 111, and a cylinder between the upper and lower disc-shaped members 112 and 113. and granular members 114 having water absorbability housed in a space (hereinafter referred to as a nutrient solution storage space) within the shaped member 111 .

In this embodiment, as the cylindrical member 111, a vinyl chloride tube having an inner diameter of 8 cm and a length of 50 cm is used. Also, the cylindrical member 111 is a black member that does not transmit light so that the light from the LED 18 does not reach the inside of the cylindrical member 111 . The disk-shaped members 112 and 113 fitted to the upper and lower portions of the cylindrical member 111 are both made of urethane sponge, and the granular member 114 is made of a cubic urethane sponge about 1 cm square. In the following description, the upper disc-shaped member 112 and the lower disc-shaped member 113 are called urethane top and urethane bottom, respectively, and the granular member 114 is called urethane particles. In this embodiment, the urethane bottom 113 is thicker than the urethane top 112 (for example, the urethane top 112 is 1 cm thick and the urethane bottom 113 is 1.8 cm thick).

The nutrient solution supplied into the cultivation pot 11 is gradually discharged from the pot 11 through the urethane bottom 113 . The liquid level of the nutrient solution in the cultivation pot 11 is adjusted by adjusting the amount of the nutrient solution supplied to the cultivation pot 11 per unit time.

A plurality of pot mounting holes 101 are formed in the upper surface of the mounting table 10, and the cultivation pots 11 are inserted therein. The nutrient solution discharged from the cultivation pot 11 through the urethane bottom 113 passes through a drainage groove formed in the mounting table 10 and is recovered from the recovery pipe into a nutrient solution recovery tank (both not shown).

The Panax ginseng seedling 200 is transplanted to the urethane top 112 of the cultivation pot 11 having the above configuration. The underground part (root part) 201 of the transplanted seedling 200 grows in a state surrounded by the urethane particles 114 inside the cylindrical member 111 . Also, the above-ground parts (stems and leaves) 202 extend upward. The length of the cylindrical member 111 is set so as not to hinder the elongation of the underground portion 201 until the ginseng is harvested. In other words, the harvesting time (the length of the growing period) is set so that the Panax ginseng is harvested before the lower end of the underground part 201 reaches the urethane bottom 113 .

(2) Examination of Cultivation Conditions Next, the conditions for hydroponic cultivation of Panax ginseng using the hydroponic cultivation apparatus 100 were examined. Here, we searched for cultivation conditions that can accelerate the growth and enlargement of the underground part of Panax ginseng and increase the amount (concentration) of the medicinal component contained in the underground part. Panax ginseng has no growth part (bud) above ground, and all photosynthetic products flow underground. Therefore, the conditions that promote photosynthesis are the conditions that increase medicinal ingredients. In addition, when photosynthetic products are excessively accumulated, secondary metabolism (triterpenoid biosynthesis) is induced, and medicinal components are accumulated underground.

Furthermore, the medicinal components of Panax ginseng do not contain nitrogen and are biosynthesized through the mevalonate pathway. It is expected that it will be a condition to In other words, it is effective to increase Zn ²⁺ and Mg ²⁺ in the nutrient solution for the purpose of increasing metabolic activity.

(2-1) Examination of Hydroponic System Seedlings of Panax ginseng cultivated in the open field for two years after germination were transplanted to the hydroponics apparatus 100, and hydroponic cultivation was carried out for 3 months. During all periods of hydroponic cultivation, hydroponic cultivation was performed using fluorescent LED lighting with a cycle of 12 hours light period and 12 hours dark period, and the composition of the nutrient solution was examined. The light intensity of the LED was set at 100-200 μmol/m ² /s.

First, the nutrient solution (EC = 1.0) according to the Otsuka A prescription (hereinafter referred to as the Otsuka A prescription nutrient solution), which is a standard nutrient solution widely used for hydroponics of fruit vegetables, leafy vegetables, and flowering plants, was used. When the seedlings of Panax ginseng were grown using this method, chlorosis occurred (see FIG. 3. FIG. 3 is a photograph of the above-ground part of Panax ginseng that was hydroponic for 3 months). Since chlorosis is a typical disorder caused by magnesium deficiency, it was found that the concentration of magnesium ions contained in the Otsuka A formula nutrient solution was insufficient for the growth of Panax ginseng.

Two magnesium ions (Mg ⁺ ) exist in the active center of DNA polymerase and play an important role in the reaction by DNA polymerase. Magnesium is an essential component for cell division. Therefore, it was speculated that magnesium deficiency not only causes damage to the above-ground part of Panax ginseng, but also inhibits the growth and enlargement of the underground part. Therefore, a nutrient solution with a higher magnesium ion concentration than the Otsuka A formula nutrient solution was prepared, and using this solution, panax ginseng was cultivated with hydroponics. Zinc (Zn) is a component necessary for protein synthesis after cell division, and is expected to promote the growth of underground parts by increasing the concentration of zinc ions in the nutrient solution. Therefore, it was decided to prepare a nutrient solution with a higher magnesium ion concentration and zinc ion concentration than the Otsuka A prescription nutrient solution, and to perform hydroponics of panax ginseng using this nutrient solution. The nutrient solution (EC=1.0) according to the Otsuka A prescription has a magnesium ion concentration of about 23 ppm and a zinc ion concentration of about 0.03 ppm.

As a result, it was found that the underground part of Panax ginseng grows greatly by using the nutrient solution with high magnesium ion concentration and zinc ion concentration in the Otsuka A prescription nutrient solution. Fig. 4 shows panax ginseng cultured hydroponically for 3 months using a nutrient solution with magnesium ion concentration and zinc ion concentration of Otsuka A prescription nutrient solution adjusted to 48 ppm and 18 ppm, respectively (hereinafter referred to as high Mg/Zn nutrient solution). (right side) and the underground part (left side) of Panax ginseng cultivated outdoors for two years. From FIG. 4, it can be seen that the underground part of Panax ginseng was greatly enlarged during the short-term hydroponic culture of 3 months. Although not shown in the photograph, the panax ginseng hydroponically cultivated in a high Mg/Zn nutrient solution did not cause chlorosis in the above-ground part (leaf part), and both the underground part and the above-ground part grew well. .

(2-2) Optimal Light Intensity In order to investigate the optimal light intensity conditions, the above-mentioned high Mg-Zn nutrient solution was used, and five different light intensities (50, 80, 120, 180, 240 μmol/m ² /s) were used. It was hydroponically cultivated for 3 months. This experiment also had a light/dark cycle of 12 hours light and 12 hours dark. After three months of hydroponic culture, the amounts (% content) of ginsenosides Rg1 and Rb1, which are medicinal ingredients contained in the underground part, were measured using high performance liquid chromatography (HPLC). The results are shown in FIG.

As can be seen from FIG. 5, the contents of both ginsenosides Rg1 and Rb1 increased as the light intensity increased. However, since the leaves died when the light intensity was 250 μmol/m ² /s or more, the light intensity must be set to less than 250 μmol/m ² /s in order to increase the amount of the medicinal ingredient.

[Example 2]
As in Example 1, seedlings of Panax ginseng cultivated in the open field for two years after germination (hereinafter referred to as second-year seedlings in the open field) were transplanted to the hydroponic cultivation apparatus 100, and hydroponic cultivation was performed for three months to increase the growth rate. , and investigated the amount of components contained in the underground part. A high Mg-Zn nutrient solution was used for nutrient cultivation. In addition, the light intensity was set to 240 μmol/m ² /s, and hydroponics was performed with a light-dark cycle of 12 hours light period and 12 hours dark period.

In this embodiment, when transplanting open-field biennial seedlings from open-field to the hydroponics apparatus 100, after washing the soil adhering to the seedlings with running water, the underground part is treated with high-concentration sodium hypochlorite (0 .1%) for 20 to 30 minutes for sterilization. In addition, after transplanting to the nutrient cultivation apparatus 100, a viable bacteria test is performed every 1 to 2 weeks. 0.01%), the cultivation pot 11 and seedlings were sterilized, and hydroponic culture was performed under conditions in which no bacteria were detected in the viable bacteria test.

FIG. 6 shows the result of comparing the fresh weight (g) of seedlings grown in open field for 3 months after transplanting the seedlings in open field to the hydroponics apparatus 100 and then performing hydroponic cultivation for 3 months. The bar graph represents the average value of 10 individuals, and the bar represents the standard error. As can be seen from FIG. 6, by transplanting to the hydroponics apparatus 100 and performing hydroponic cultivation for 3 months, the fresh weight increased by about 1.8 times at the time of transplantation.

The photograph of FIG. 7 shows the result of treating the underground part of seedlings which had been subjected to hydroponic culture for 3 months in the open field for 2 years and then treated with an iodine solution. The photograph on the left side of FIG. 7 is the tip of the underground portion, and the middle photograph is the upper portion of the underground portion (upper root). The photograph on the right is a photograph of the upper part of the root that was not treated with the iodine solution. If the subterranean part contains starch, the iodine treatment will turn the subterranean part dark brown. These pictures show the accumulation of starch throughout the subterranean part.

FIG. 8 shows the results of examination of the concentration of macroelements in the upper part of the underground part of the seedling, the middle part of the root, and the fine root of the two-year-old seedling in the open field, which was subjected to hydroponic cultivation for three months. As can be seen from FIG. 8, the concentration of potassium (K ⁺ ) is the highest in all of the upper part of the root, the middle part of the root, and the fine root. more than twice the concentration.

FIG. 9 shows the results of investigating the concentration of trace elements in the upper part of the underground part of the seedling, the middle part of the root, and the fine root of the seedling which was subjected to hydroponics for 3 months. As can be seen from FIG. 9, the iron ion (Fe ³⁺ ) concentration is highest in all of the upper part of the root, the middle part of the root, and the fine root. It was more than 6 times the concentration.

Fig. 10 shows the contents of medicinal components (ginsenosides Rg1 and Rb1) contained in the underground parts of seedlings that were hydroponically cultivated in open field for 3 months using high Mg-Zn nutrient solution and Otsuka A prescription nutrient solution. (content rate). As can be seen from FIG. 10, the seedlings hydroponic using the high Mg Zn nutrient solution contain more medicinal components contained in the underground than the seedlings hydroponic using the Otsuka A prescription nutrient solution. rate increased.

[Example 3]
In Examples 1 and 2 described above, the second-year seedlings cultivated in the open field were transplanted to the hydroponics apparatus 100 and hydroponic cultivation was performed. When transplanting to 100 and after transplanting, even if sterilization treatment is performed, seedlings may rot during the process. Therefore, in this example, hydroponics was studied not only during the growth period but also during the germination period and the seedling raising period.

11 and 12 are schematic configuration diagrams of the cultivation container used in this example. The cultivation container 30 was used for hydroponics during the germination period and seedling raising period, and the cultivation container 40 was used for hydroponic cultivation during the growth period. Cultivation containers 30 and 40 are used in place of the cultivation pot 11 in FIG. 1, and other configurations of the hydroponics apparatus 100 are substantially the same as those shown in FIG.

The cultivation container 30 is a cubic container made of an opaque plate material, and the inner bottom surface of the container has dimensions of 2 to 3 cm (vertical) x 20 cm (horizontal), and the height (depth) of the container 30 is 10 cm. is set. Urethane particles 114 similar to those in the cultivation pot 11 are accommodated in the container 30 . Although FIG. 11 depicts the urethane particles 114 sparsely positioned within the container 30 , the container 30 is actually substantially filled with the urethane particles 114 .

A spacer 31 made of an opaque member is arranged on the top of the cultivation container 30, and the spacer 31 is formed with a plurality of seeding holes. A urethane germination bed (not shown) is placed under the spacer 31, and seeds are sown on the germination bed through the holes. The spacer 31 prevents the light from the LED 18 from entering the cultivation container 30 .

Like the cultivation container 30, the cultivation container 40 consists of a cubic container formed of an opaque plate material, and the dimensions of the inner bottom surface of the container are 5 to 6 cm (vertical) x 60 cm (horizontal). height) is set to 60 cm. Urethane particles 114 are accommodated in the container 40 as in the cultivation pot 11 . Although FIG. 12 depicts the urethane particles 114 sparsely positioned within the container 40 , the container 40 is actually substantially filled with the urethane particles 114 .

A spacer 41 made of an opaque member is arranged on the top of the cultivation container 40, and the spacer 31 is formed with a plurality of holes for seedling transplantation. A seedling is transplanted through the hole of the spacer 41 . The spacer 41 prevents the light from the LED 18 from entering the cultivation container 40 .

Water supply cocks 32 and 42 are attached to one end of the upper portion (left end in FIGS. 11 and 12) of the cultivation containers 30 and 40, and drain cock 33 is attached to one end of the lower portion (right end in FIGS. 11 and 12). 43 is attached. By opening and closing the water supply cocks 32 and 42 and the drain cocks 33 and 43, the cultivation containers 30 and 34 can be switched between a state in which the nutrient solution is stored and a state in which the nutrient solution is not stored. A water supply pipe 19 of the cultivation apparatus 100 is connected to the water supply cocks 32 and 42 . Also, the nutrient solution discharged from the drain cocks 33 and 43 passes through a drainage groove provided on the mounting table 10 and is recovered from a recovery pipe into a nutrient solution recovery tank (both not shown).

In this example, the germination period was the period from seeding to 5 days after germination, and the seedling-raising period was the period from 5 days after germination to 3 years after germination. Also, the growing period was the period from the third year after germination until harvesting, which was three months in this example. A high Mg·Zn nutrient solution was used during all periods of germination, seedling raising and growth. In addition, the light intensity was set to 240 μmol/m ² /s, and hydroponics was performed with a light-dark cycle of 12 hours light period and 12 hours dark period. In addition, in all periods, during one light-dark cycle, the first state in which 80% or more of the underground part of the seedling of Panax ginseng is immersed in the nutrient solution and 80% or more of the underground part is exposed to the air. an aeration step in which the liquid level of the nutrient solution in the cultivation containers 30 and 40 is moved up and down so as to alternately repeat the second state in which the seedlings are placed; An immersion treatment step was performed alternately to maintain the height so that 80% or more of the part was immersed in the nutrient solution.

First, the aeration process and the immersion treatment process are alternately performed for 1 hour each, and the time ratio of the first state and the second state in the aeration process is 60 minutes: 0 minutes, 15 minutes: 45 minutes, 30 minutes: 30 minutes, 45 minutes. : The change in fresh weight due to the change in 15 minutes was examined. Table 1 shows the average fresh weight (g) of 10 individuals after performing hydroponics during the seedling raising period for 3 months. The aeration time in Table 1 represents the time in the second state. In other words, the aeration time of "0 minutes" means that the hydroponic culture was performed by immersing the underground portion in the hydroponic solution during the entire cultivation period.

As can be seen from Table 1, the fresh weight was the lowest when the second state was 0 minutes, and the highest when the second state was 30 minutes. Moreover, the fresh weights in the second state of 15 minutes and 45 minutes were substantially the same.

Next, the aeration process and the immersion treatment process were alternately performed for 1 hour, 3 hours and 12 hours, respectively, and the change in the fresh weight at each time was examined. In each aeration step, the time ratio between the first state and the second state was 30 minutes:30 minutes. Table 2 shows the average fresh weight (g) of 10 individuals at that time.

In Table 2, the aeration cycle time represents the execution time of the aeration process (immersion treatment process). In Table 2, the cycle time of the aeration step of 0 hours means that hydroponics was performed without performing the aeration step. As can be seen from Table 2, the fresh weight was the highest when the aeration process and the immersion treatment process were performed for 3 hours each, and the fresh weight was the lowest when the aeration process was not performed.

DESCRIPTION OF SYMBOLS 100... Hydroponics apparatus 10... Mounting table 11... Cultivation pot 12... Nutrient solution tank 13... Liquid feeding pipe 14... Liquid feeding pump 16... Support 17... Ceiling part 18... LED
19... Water supply pipe 20... Controllers 30, 40... Cultivation containers 31, 41... Spacers 32, 42... Water supply cocks 33, 43... Drainage cocks

Claims (8)

At least during the period from sowing to harvesting, the growth period is a period in which seedlings whose underground parts have grown to a predetermined size are cultivated until they are harvested. Cultivation of panax ginseng using a nutrient solution containing fertilizer components necessary for the growth of the underground part in a light-dark cycle that alternately repeats a dark period in which the above-ground part is irradiated with a lower amount of light than the light period. A method for hydroponic cultivation of Panax ginseng,
A first state in which 80% or more of the underground portion is immersed in the nutrient solution and a second state in which more than half of the underground portion is exposed to the air during one light-dark cycle during the growth period. is performed at least once in which the liquid level of the nutrient solution is moved up and down so as to alternately repeat A hydroponic cultivation method in which a step of immersion treatment is performed to maintain a height such that 80% or more of the plant is immersed in the nutrient solution. 2. The hydroponics method for Panax ginseng according to claim 1, wherein said second state of said aeration step is set within a time range of 15 minutes to 45 minutes. In the hydroponics method according to claim 1 or 2,
A hydroponics method for panax ginseng, wherein the immersion treatment step and the aeration step are alternately performed at a cycle of 3 to 12 hours. Among the cultivation period from sowing to harvesting, the germination period, which is the period of cultivation from sowing to germination, and the seedling-raising period, which is the period of cultivation until the underground part of the germinated seedling grows to a predetermined size. Cultivated using a nutrient solution containing the fertilizer components necessary for the growth of the part,
4. Any one of claims 1 to 3, wherein during the seedling raising period, the aeration step is performed at least once during one light/dark cycle, and the immersion treatment step is performed during a time other than the aeration step of the one light/dark cycle. 3. The hydroponics method for panax ginseng according to 1. 5. The hydroponics method for panax ginseng according to claim 4, wherein the seeds are germinated at a low temperature during the germination period. The hydroponic cultivation method according to any one of claims 1 to 5, wherein the concentration of magnesium ions contained in the nutrient solution is in the range of 40 ppm to 56 ppm, and the concentration of zinc ions is in the range of 10 to 26 ppm. In the hydroponic cultivation method according to claim 1,
Out of the period from sowing to harvesting, the germination period, which is the period from sowing to germination, and the raising seedling period, which is the period of cultivation until the underground part of the germinated seedling grows to a predetermined size, are carried out by outdoor cultivation. , the growth period is to perform hydroponic cultivation using a predetermined hydroponic cultivation apparatus,
When transplanting the seedlings whose seedling raising period has ended from the open field to the hydroponic cultivation apparatus, the underground part of the seedlings is sterilized with high-concentration sodium hypochlorite water, and after transplanting into the hydroponic cultivation apparatus A hydroponics method for Panax ginseng, wherein the underground part of the seedling is periodically sterilized with low-concentration sodium hypochlorite water. Hydroponic culture is performed by housing the underground part and a water-absorbent member arranged to surround the underground part in a cultivation container having a depth that does not hinder the elongation of the underground part of Panax ginseng during the growth period. Item 8. The method for hydroponic cultivation of panax ginseng according to any one of items 1 to 7.

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