Patent Publication Number: US-2016219809-A1

Title: Hydroponic cultivation apparatus and hydroponic cultivation method

Description:
TECHNICAL FIELD 
     The present invention relates to a hydroponic cultivation apparatus for, and a hydroponic cultivation method of, growing a plant. 
     BACKGROUND ART 
     Some perennial plants enter dormant phases. For this reason, there is likelihood that some perennial plants need long growth periods unique to them to be grown. Meanwhile, techniques for shortening plant growth periods have been disclosed in PTLS 1 and 2. 
     A plant growth method disclosed in PTL 1 supplies a plant vitalizer including organic compounds to a stem of the plant while a plant is growing. Thereby, the plant growth method shortens a growth period of the plant by accelerating the growth of the plant. 
     A plant growth method disclosed in PTL 2 shortens the dormant phase of the plant by genetically modifying the plant. 
     CITATION LIST 
     Patent Literature 
     [PTL 1] Japanese Unexamined Patent Application Publication No.2007-195546 
     [PTL 2] Japanese Unexamined Patent Application Publication No.2005-229823 
     SUMMARY OF INVENTION 
     Technical Problem 
     Nevertheless, the plant growth method disclosed in PTL 1 only accelerates the growth of the plant in the plant growth process. For this reason, this plant growth method cannot shorten the dormant phase of a perennial plant. 
     Meanwhile, a plant grown using the plant growth method disclosed in PTL 2 is genetically different from a plant of the same kind and has a problem if it is used as a food plant or a medical plant. 
     The present invention has been proposed with the foregoing situations taken into consideration. An object of the present invention is to provide a hydroponic cultivation apparatus and a hydroponic cultivation method which are capable of shortening a dormant phase of a plant without genetically modifying the plant. 
     Solution to Problem 
     A first aspect of the present invention provides a hydroponic cultivation apparatus for growing a plant by circulating a nutrient solution, including: a hydroponic container configured to hold the nutrient solution; a support portion configured to support the plant; a nutrient solution supply unit configured to supply the nutrient solution to the hydroponic container; a nutrient solution discharging unit configured to discharge the nutrient solution from the hydroponic container; and a budding enhancer supply unit configured to supply a budding enhancer to the plant. 
     A second aspect of the present invention provides the hydroponic cultivation apparatus according to the first aspect, in which the budding enhancer supply unit supplies the budding enhancer to a bud of the plant. 
     A third aspect of the present invention provides the hydroponic cultivation apparatus according to the second aspect, in which the budding enhancer supply unit drops the budding enhancer onto the bud. 
     A fourth aspect of the present invention provides the hydroponic cultivation apparatus according to the second aspect, in which the budding enhancer supply unit is a member containing the budding enhancer. 
     A fifth aspect of the present invention provides the hydroponic cultivation apparatus according to the fourth aspect, further including a height adjuster configured to adjust a height of the budding enhancer supply unit. 
     A sixth aspect of the present invention provides the hydroponic cultivation apparatus according to the first aspect, in which the budding enhancer supply unit is configured to contain the budding enhancer in at least a part of the support portion which is in contact with the plant. 
     A seventh aspect of the present invention provides the hydroponic cultivation apparatus according to the fourth aspect, in which the member containing the budding enhancer is placed on the support portion, and includes a hole provided above a part of support portion in which the plant produces the bud. 
     An eighth aspect of the present invention provides the hydroponic cultivation apparatus according to the first or second aspect, wherein the budding enhancer supply unit sprays the budding enhancer onto the plant. 
     A ninth aspect of the present invention provides the hydroponic cultivation apparatus according to any one of the first to the eighth aspect, in which the budding enhancer includes a plant hormone. 
     A tenth aspect of the present invention provides a hydroponic cultivation method of growing a plant by circulating a nutrient solution, wherein during a dormant phase in which a perennial plant as the plant is in dormancy, the perennial plant is supplied with not only the nutrient solution but also a budding enhancer. 
     An eleventh aspect of the present invention provides the hydroponic cultivation method according to the tenth aspect, in which the budding enhancer includes a plant hormone. 
     Advantageous Effects of Invention 
     The present invention is capable of shortening a dormant phase of a plant by supplying a budding enhancer to a plant without genetically modifying the plant. 
    
    
     
       BRIEF DESCRIPTION OF DRAWINGS 
       FIG.  1   
         FIG. 1  is a partial cross-sectional diagram illustrating an example of a configuration of a hydroponic cultivation apparatus shown as an embodiment of the present invention. 
       FIG.  2   
         FIG. 2  is a partial cross-sectional diagram illustrating an example of a configuration of another hydroponic cultivation apparatus shown as the embodiment of the present invention. 
       FIG.  3   
         FIG. 3  is a partial cross-sectional diagram illustrating an example of a configuration of another hydroponic cultivation apparatus shown as the embodiment of the present invention. 
       FIG.  4   
         FIG. 4  is a partial cross-sectional diagram illustrating an example of a configuration of another hydroponic cultivation apparatus shown as the embodiment of the present invention. 
       FIG.  5   
         FIG. 5  is a partial cross-sectional diagram illustrating an example of a configuration of another hydroponic cultivation apparatus shown as the embodiment of the present invention. 
       FIG.  6   
         FIG. 6  is a partial cross-sectional diagram illustrating an example of a configuration of another hydroponic cultivation apparatus shown as the embodiment of the present invention. 
       FIG.  7   
         FIG. 7  is a partial cross-sectional diagram illustrating an example of a configuration of another hydroponic cultivation apparatus shown as the embodiment of the present invention. 
       
         FIG. 8 
       
         FIG. 8  is a partial cross-sectional diagram illustrating an example of a configuration of another hydroponic cultivation apparatus shown as the embodiment of the present invention. 
     
    
    
     DESCRIPTION OF EMBODIMENTS 
     Referring to the drawings, descriptions will be hereinbelow provided for the embodiment of the present invention. 
     A hydroponic cultivation apparatus shown as an embodiment of the present invention has a configuration as shown in  FIG. 1 , for example. This hydroponic cultivation apparatus is used for hydroponic culture in which a plant  100  is grown without soil. Incidentally, although  FIG. 1  shows the single plant  100  is being grown by the hydroponic cultivation apparatus, several or a large number of plants  100  may be grown by the hydroponic cultivation apparatus. 
     The hydroponic cultivation apparatus grows the plant  100  by supplying liquids to at least branch roots  103  of the plant  100 . The hydroponic cultivation apparatus shown as the embodiment will be explained in which the plant  100  is a plant synthesizing nutrients in its aboveground part and accumulating the thus-synthesized nutrients in its underground part, that to say, a root vegetable. 
     A cited example of the root vegetable is Panax ginseng (Korean ginseng, Goryeo insam) as the plant  100  shown in  FIG. 1 . Although the embodiment shows, for example, Panax ginseng as the plant  100 , the plant  100  is not limited to this. 
     In addition, the plant  100  of the embodiment may be a perennial plant that takes several years to grow. This perennial plant grows through a repeated series of a growth phase in which the plant grows bigger accumulating nutrient and a dormant phase in which the plant growth is suspended. The dormant phase is that needed for the plant to survive the winter in a farm field. 
     Furthermore, the embodiment will be described in which a nutrient solution is circulated to help the plant  100  to grow during the growth phase of the plant  100 . Cited examples of the nutrient solution include water, and a culture solution obtained by adding nutrients to water. 
     The hydroponic cultivation apparatus includes a hydroponic container  1 . The hydroponic container  1  is that configured to grow the plant  100 . The hydroponic container  1  holds a nutrient solution  110  in its bottom portion. The hydroponic container  1  of the hydroponic cultivation apparatus is provided with a support portion  2  for supporting a taproot  101  of the plant  100 . The hydroponic cultivation apparatus applies water to the branch roots  103  of the plant  100  with the plant  100  supported thereby. 
     The support portion  2  is attached to an opening portion in an upper end of the hydroponic container  1 , and supports the plant  100 . The support portion  2  is made from a sponge or the like which is provided to and closes the opening portion in the upper end of the hydroponic container  1 . 
     The support portion  2  is formed to include a through-hole for the plant  100 . The support portion  2  is elastically deformed in accordance with a change in the shape of a side surface of the plant  100  when the plant  100  grows, and supports the plant  100  with resilience from the elastic deformation. Incidentally, any configuration may be used for the support portion  2 , as long as the configuration is capable of supporting the plant  100 , such as a cord suspending the aboveground part of the plant  100 . 
     An upper end of the taproot  101  is exposed to the outside from the support portion  2  while the plant  100  is being supported by the support portion  2 . A bud  102  grows from the upper end of the taproot  101 . 
     In some perennial plants, when they enter dormancy, leaves and stems in their aboveground parts wither. After the end of dormancy, the plant  100  produces the bud  102 . Nevertheless, the hydroponic cultivation apparatus of the embodiment makes the plant  100  produce the bud  102  by supplying a budding enhancer to the plant  100  in order to prevent the plant  100  from entering dormancy, as described later. 
     The hydroponic cultivation apparatus includes a nutrient solution supply unit  3 . The nutrient solution supply unit  3  is formed from a pipe through which to supply the nutrient solution, which is held in a nutrient solution container, albeit not illustrated. The nutrient solution supply unit  3  penetrates through the support portion  2  from above to below. The nutrient solution supply unit  3  is provided with a nutrient solution supply port under the support portion  2 . The nutrient solution supply unit  3  drops a nutrient solution  111 , which is supplied from the nutrient solution container, into the hydroponic container  1 . 
     The hydroponic cultivation apparatus further includes a nutrient solution discharging unit  5 . The nutrient solution discharging unit  5  discharges the nutrient solution  110  from the hydroponic container  1 . The nutrient solution discharging unit  5  is formed from a pipe provided with an upper opening for the nutrient solution  2  to flow in at a predetermined height in the hydroponic container  1 , for example. After the amount of nutrient solution  110  reaches the predetermined height, part of the solution  110  above the height can be discharged as a waste solution  113  from the upper opening of the nutrient solution discharging unit  5 . Thereby, the hydroponic cultivation apparatus circulates the nutrient solution  110  stored inside the hydroponic container  1 . 
     The hydroponic cultivation apparatus further includes a budding enhancer supply unit  4 . The budding enhancer supply unit  4  is formed from a pipe through which to supply the budding enhancer, which is held in a budding enhancer container, albeit not illustrated, using a pump or the like. The budding enhancer supply unit  4  penetrates through the support portion  2  from above to below the support portion  2 . 
     The budding enhancer supply unit  4  is provided with a budding enhancer supply port under the support portion  2 . The budding enhancer supply unit  4  drops a budding enhancer  112 , which is supplied from the budding enhancer container using the pump or the like, into the hydroponic container  1 . 
     Thereby, the budding enhancer  112  is mixed into the nutrient solution  110  held in the hydroponic container  1 . Thereby, the budding enhancer is supplied to the branch roots  103  of the plant  100 . 
     The budding enhancer  112  includes plant hormones. As the plant hormones, at least either a gibberellin or kinetin is usable. The plant hormones act on the plant  100  to break dormancy of the plant  100 . In other words, the supply of the budding enhancer  112  to the plant  100 , while dormant, makes the plant  100  produce the bud  102 . 
     Moreover, it is desirable that the budding enhancer supply unit  4  be configured to supply the budding enhancer  112  at arbitrary timing. To this end, the hydroponic cultivation apparatus is provided with the budding enhancer supply unit  4  as a channel separated from the nutrient solution supply unit  3 . 
     It should be noted that the budding enhancer  112  may be supplied to the plant  100  at least during the dormant phase in which the plant  100  is dormant. Furthermore, the budding enhancer  112  may be supplied to the plant  100 , too, during the growth phase in which the plant  100  is not dormant. 
     Moreover, with regard to a method of supplying the budding enhancer  112 , the budding enhancer  112  may be directly supplied to the bud  102  which grows newly. Otherwise, the budding enhancer  112  may be temporarily mixed into the nutrient solution  111  so that the budding enhancer  112  can be absorbed by the branch roots  103 . Meanwhile, an appropriate concentration of the budding enhancer  112  may be changed depending on the method of supplying the budding enhancer  112 , as well as the size and growth level of the plant  100  to which the budding enhancer  112  is given. For example, in a case where a gibberellin is used as the budding enhancer  112 , approximately 0.01 ppm to 1000 ppm of the budding enhancer  112  may be given to the plant  100  depending on the size and growth level of the plant  100 . 
     It is desirable that the concentrations of the plant hormones as the budding enhancer  112  in the nutrient solution  110  be set appropriately. Moreover, it is desirable that the plant hormones as the budding enhancer  112  be supplied to an appropriate part of the plant  100 . Thereby, physiological disorder of the plant  100  can be inhibited. 
     Besides, even if the budding enhancer  112  is mixed into the nutrient solution  110  unintentionally inside the hydroponic container  1 , the mixture cause no problem to the growth of the nutrient solution  110 . 
     As described above, the hydroponic cultivation apparatus described as the embodiment grows the plant  100  by circulating the nutrient solution  110 . The hydroponic cultivation apparatus includes the hydroponic container  1  in which to hold the nutrient solution  110  for growing the plant  100 . The hydroponic cultivation apparatus further includes the support portion  2  for supporting the plant  100 . The hydroponic cultivation apparatus further includes the nutrient solution supply unit  3  for supplying the nutrient solution  111  to the hydroponic container  1 . The hydroponic cultivation apparatus further includes the nutrient solution discharging unit  5  for discharging the nutrient solution  110  from the hydroponic container  1 . The hydroponic cultivation apparatus further includes the budding enhancer supply unit  4  for supplying the budding enhancer  112  to the plant  100 . 
     Moreover, the embodiment makes it possible to carry out the hydroponic cultivation method in which the plant  100  is grown by circulating the nutrient solution  110 . In addition, the hydroponic cultivation method supplies both the nutrient solution  111  and the budding enhancer  112  to the perennial plant as the plant  100  during the dormant phase in which the perennial plant is dormant. 
     The hydroponic cultivation apparatus like this is capable of giving the budding enhancer  112  to the plant  100  using the budding enhancer supply unit  4 . Thereby, even if the plant  100  is dormant, the hydroponic cultivation apparatus is capable of growing the plant  100  by arbitrarily making the plant  100  cause budbreak. Accordingly, the hydroponic cultivation apparatus is capable of shortening the dormant phase of the plant  100  without genetically modifying the plant  100 . 
     Furthermore, the hydroponic cultivation apparatus is capable of making the plant  100  grow faster by giving the budding enhancer  112  to the plant  100  than by giving no budding enhancer  112  to the plant  100 . 
     Moreover, in a case where the hydroponic cultivation apparatus grows a large number of plants  100 , the hydroponic cultivation apparatus is capable of inhibiting variations in budbreak timing among the plants  100 . For example, the hydroponic cultivation apparatus is capable of supplying the budding enhancer to plants  100  which have not produced their buds yet, while the hydroponic cultivation apparatus is capable of stopping the supply of the budding enhancer to plants  100  which have already produced their buds. 
     Besides, since the hydroponic cultivation apparatus shortens the dormant phase of the plant  100 , the plant  100  need not be genetically modified. The plant  100  grown by the hydroponic cultivation apparatus is not genetically different from the plant  100  naturally grown. 
     What is more, the hydroponic cultivation apparatus uses the plant hormones as the budding enhancer. The plant hormones are naturally included within the plant  100 . For this reason, the hydroponic cultivation apparatus is capable of reducing a chance of abnormal morphologies occurring in the plant  100 , even if it is grown with the budding enhancer. 
     Next, descriptions will be provided for another embodiment of the present invention. In the following embodiment, components which are the same as those of the foregoing embodiment will be denoted by the same reference signs, and detailed descriptions for such components will be omitted. 
     As shown in  FIG. 2 , a hydroponic cultivation apparatus shown as the embodiment of the present invention may be configured such that a budding enhancer supply unit  4  supplies a budding enhancer  112  to a bud  102  of a plant  100 . 
     The plant  100  produces a new bud  102  after entering dormancy and letting its aboveground part wither. With this taken into consideration, the hydroponic cultivation apparatus supplies a budding enhancer  112  directly to a part of the plant  100  from which the bud  102  grows, or the new bud  102 . 
     The plant  100  can absorb the budding enhancer  112 , which is supplied from the budding enhancer supply unit  4 , from the bud  102 . Thereby, the plant  100  can make the bud  102  grow faster. 
     The hydroponic cultivation apparatus is capable of making a time period leading to the budbreak become shorter than one in which the budding enhancer  112  is absorbed from branch roots  103 . Furthermore, the hydroponic cultivation apparatus can make the plant  100  less likely to form abnormal morphologies. 
     It should be noted that the hydroponic cultivation apparatus may be configured such that the budding enhancer supply unit  4  supplies the budding enhancer  112  to a nutrient solution  110  as shown in  FIG. 1 , as well as to the bud  102 . 
     As another embodiment of the present invention, for example, a budding enhancer  112  may be dropped onto a bud  102  of a plant  100 , as shown in  FIG. 3 . A budding enhancer supply unit  4  has a drip nozzle  4   a  at a distal end of a pipe through which to supply the budding enhancer  112 . 
     This hydroponic cultivation apparatus is configured such that a position at which the budding enhancer supply unit  4  supplies the budding enhancer  112  can be moved in accordance with a position of the bud  102  of the plant  100 . Otherwise, the hydroponic cultivation apparatus adjusts a position of the plant  100  to be grown to a placement position of the drip nozzle  4   a.  A position from which the budding enhancer  112  drips is placed right above the bud  102  so that the budding enhancer supply unit  4  drops the budding enhancer  112  directly onto the bud  102 . 
     The budding enhancer supply unit  4  may drop the budding enhancer  112  onto the bud  102  of the plant  100  only at needed times while the plant  100  is in dormancy. After the plant  100  enters dormancy, the budding enhancer supply unit  4  drops a predetermined amount of budding enhancer  112  at predetermined intervals which are set in advance. 
     This hydroponic cultivation apparatus supplies the budding enhancer  112  directly to the bud  102 . For this reason, the hydroponic cultivation apparatus enables the plant  100  to form the bud  102  even if the concentration of the budding enhancer  112  is set low. 
     In addition, this hydroponic cultivation apparatus is capable of inhibiting unnecessary absorption of the budding enhancer  112 . Thereby, despite the use of the budding enhancer  112 , the hydroponic cultivation apparatus can make the plant  100  less likely to form abnormal morphologies. 
     Furthermore, in the case where this hydroponic cultivation apparatus grows multiple plants  100 , the hydroponic cultivation apparatus is capable of selecting plants  100  onto which the budding enhancer  112  should be dropped. Thereby, the hydroponic cultivation apparatus is capable of selectively making the plants  100  form their buds  102 . 
     As another embodiment of the present invention, for example, a budding enhancer supply unit  4  may be formed from a member ( 4   b,    4   c ) containing a budding enhancer, as shown in  FIG. 4 . This member may be made from a water-absorbent material. This budding enhancer supply unit  4  is placed, for example, on an upper surface of a support portion  2 . Thereby, the budding enhancer supply unit  4  makes the member containing the budding enhancer stay in contact with buds  102 . 
     The member made from sponge or the like may be used as the budding enhancer supply unit  4 . In a case where sponge is used as the budding enhancer supply unit  4 , the lower portion  4   b  absorbing the budding enhancer in the budding enhancer supply unit  4  is in contact with the buds  102 . Thereby, the budding enhancer supply unit  4  is capable of supplying the budding enhancer directly to the buds  102 . 
     In the case where sponge or the like is used as the budding enhancer supply unit  4 , the sponge or the like is placed on new buds  102  which broke several hours ago to several days ago. Incidentally, the hydroponic cultivation apparatus may be configured such that the budding enhancer supply unit  4  is refilled with the budding enhancer from the upper portion  4   c  of the sponge. Furthermore, in a case where a brush or the like is used as the budding enhancer supply unit  4 , the budding enhancer can be applied to the buds  102  using the brush or the like by making the brush or the like reciprocate while sliding the brush or the like over the buds  102 . 
     Even in the case where a brush-like member or the like is used as the member containing the budding enhancer, the budding enhancer is held by the tip of the brush-like member or the like by being supplied to the brush-like member or the like through a budding enhancer container and a pipe, for example. Thereafter, the tip of the brush-like member or the like is brought into contact with the buds  102 . Thereby, the budding enhancer supply unit  4  is capable of supplying the budding enhancer  112  directly to the buds  102 . 
     Since the thus-configured hydroponic cultivation apparatus uses the member containing the budding enhancer as the budding enhancer supply unit  4 , the hydroponic cultivation apparatus is capable of supplying the budding enhancer to the multiple buds  102  evenly at the same time. For this reason, the plants  100  can be grown industrially using the hydroponic cultivation apparatus. 
     A hydroponic cultivation apparatus as another embodiment of the present invention may be the hydroponic cultivation apparatus shown in  FIG. 4 , which as shown in  FIGS. 5( a ) and 5( b ) , includes a height adjuster  10  for adjusting the height of the budding enhancer supply unit  4 . 
     The height adjuster  10  changes the height of the budding enhancer supply unit  4  manually or automatically. The height adjuster  10  is capable of arbitrarily selecting times and timing at which a budding enhancer is supplied to buds  102 . 
     For each period for which the budding enhancer is supplied to the buds  102 , the height adjuster  10  adjusts a height t1 of the budding enhancer supply unit  4 , as shown in  FIG. 5( a ) , in order to bring the budding enhancer supply unit  4  into contact with the buds  102 . On the other hand, for each period for which the budding enhancer is not supplied to the buds  102 , the height adjuster  10  adjusts a height t2 of the budding enhancer supply unit  4 , as shown in  FIG. 5( b ) , in order not to bring the budding enhancer supply unit  4  into contact with the buds  102 . 
     Since this hydroponic cultivation apparatus adjusts the height of the budding enhancer supply unit  4  using the height adjuster  10 , the hydroponic cultivation apparatus is capable of supplying the budding enhancer to the buds  102  only at needed times. 
     A hydroponic cultivation apparatus as another embodiment of the present invention may be configured such that as shown in  FIG. 6 , a budding enhancer supply unit  4  contains a budding enhancer in at least a part of a support portion  20  which is in contact with a plant  100 . 
     In this hydroponic cultivation apparatus, a water-absorbent material such as sponge is selected for the support portion  20 . Thereby, the hydroponic cultivation apparatus allows the budding enhancer to be contained in the support portion  20 . In addition, the part of the support portion  20  which contains the budding enhancer may be the entirety of the support portion  20 , or a specific part surrounding the plant  100 . 
     This hydroponic cultivation apparatus supports a side surface of the plant  100  using the support portion  20 . The supply of the budding enhancer to the support portion  20  with the plant  100  supported using the support portion  20  means that the budding enhancer can be supplied to a taproot  101  of the plant  100 . Incidentally, the hydroponic cultivation apparatus may be refilled with the budding enhancer from above the support portion  20  at arbitrary timing. 
     The thus-configured hydroponic cultivation apparatus does not supply the budding enhancer directly to a bud  102 . Furthermore, unlike in the cases described using  FIGS. 4, 5 ( a ) and  5 ( b ), the member containing the budding enhancer will not be brought into contact with the bud  102 . For this reason, in this hydroponic cultivation apparatus, the configuration for supplying the budding enhancer will not be an obstacle to a new bud which the plant  100  produces. 
     In a hydroponic cultivation apparatus as another embodiment of the present invention, it is desirable that as shown in  FIG. 7 , the member containing a budding enhancer be placed on a support portion  2 , and include hole portions  4   d  provided above parts of plants  100  where the plants  100  produce buds  102 . 
     In this hydroponic cultivation apparatus, a lower portion  4   b  of the member containing the budding enhancer is in contact with the support portion  2 . The hydroponic cultivation apparatus may be configured such that the support portion  2  absorbs the budding enhancer from the lower portion  4   b  of the member containing the budding enhancer, and gives the budding enhancer to taproots  101  of the plants  100 . In addition, the lower portion  4   b  of the member containing the budding enhancer may take on a shape which allows the lower portion  4   b  to continue in contact with the growing plants  100 . 
     In this hydroponic cultivation apparatus, the hole portions  4   d  may be provided to the member containing the budding enhancer at its parts where the buds  102  are expected to grow, in order for the member containing the budding enhancer not to hinder the buds  102  which grow from the plants  100  entering dormancy. For example, the hole portions  4   d  may be like cuts which is as small as several millimeters. 
     In the thus-configured hydroponic cultivation apparatus, it is inside the hole portions  4   d  where the buds  102  break, as well as leaves and stems  104  grow from the buds  102 . For this reason, in this hydroponic cultivation apparatus, the member containing the budding enhancer does not hinder the budbreak of the plants  100 . Nor does the hydroponic cultivation apparatus hinder the plants  100  from producing the buds  102 , or their aboveground parts from growing. Meanwhile, this hydroponic cultivation apparatus is capable of easily switching between the supply of the budding enhancer and the suspension of the supply of the budding enhancer. 
     A hydroponic cultivation apparatus as another embodiment of the present invention may be configured such that as shown in  FIG. 8 , a budding enhancer  112  in spray is supplied a plant  100 . The hydroponic cultivation apparatus includes: a nutrient solution supply unit  3  for spraying a nutrient solution  111 ; and a budding enhancer supply unit  4  for spraying the budding enhancer  112 . 
     The nutrient solution supply unit  3  is connected to a nutrient solution supply pipe, albeit not illustrated. The nutrient solution supply unit  3  sprays the nutrient solution  111 , which is supplied from the nutrient solution supply pipe, in the form of mist from a nozzle. The thus-sprayed nutrient solution  111  is attached to a taproot  101  and branch roots  103  of the plant  100 . Thereby, the nutrient solution supply unit  3  is capable of supplying the nutrient solution  111  to the plant  100 . 
     The budding enhancer supply unit  4  is connected to a pipe, albeit not illustrated. The budding enhancer supply unit  4  sprays the budding enhancer  112 , which is supplied from the pipe; from a nozzle. The thus-sprayed budding enhancer  112  is attached to the taproot  101  and the branch roots  103  of the plant  100 . Thereby, the budding enhancer supply unit  4  is capable of supplying the budding enhancer  112  to the plant  100 . 
     It should be noted that a method of spraying the nutrient solution  111  and the budding enhancer  112  may be arbitrary. Cited examples of the spraying method include a spraying method using a high-pressure gas, and an ultrasonic mist method. Furthermore, it is desirable that timing at which the nutrient solution  111  and the budding enhancer  112  are sprayed, and amounts of nutrient solution  111  and budding enhancer  112  to be sprayed be adjusted arbitrarily. 
     In addition, the position at which the budding enhancer  112  is supplied by the hydroponic cultivation apparatus is not limited to one which is shown in  FIG. 8 . The budding enhancer  112  may be sprayed from above the taproot  101 . 
     Moreover, the hydroponic cultivation apparatus may be configured such that only the budding enhancer  112  is supplied in the form of mist while the nutrient solution  111  is supplied using another method such as the foregoing subirrigation method. 
     The hydroponic cultivation apparatus enables the budding enhancer  112  to be absorbed into all the branch roots  103  of the plant  100  evenly, since the budding enhancer  112  in the form of mist is supplied to the plant  100 . 
     It should be noted that the foregoing embodiments are examples of the embodiment. For this reason, the present invention is not limited to the foregoing embodiments. It is a matter of course that besides these embodiments, various modifications can be made depending of designs and the like within a scope not departing from the technical ideas of the present invention. In addition, this application claims priority based in Japanese Patent Application No. 2013-211347 filed on Oct. 8, 2013, and all the contents of the Japanese application are incorporated herein. 
     REFERENCE SIGNS LIST 
       1  hydroponic container 
       2  support portion 
       3  nutrient solution supply unit 
       4  budding enhancer supply unit 
       4   a  drip nozzle 
       4   d  hole portions 
       5  nutrient solution discharging unit 
       10  height adjuster 
       100  plant 
       101  taproot 
       102  bud 
       110 ,  111  nutrient solution 
       112  budding enhancer