System and method for supplying a growth medium to a plant

Abstract

The present invention relates to a system for supplying a growth medium to a plant. The system comprises a container for receiving the plant, a first conduit for fluidly connecting the container to a reservoir having the growth medium, and a suction device fluidly connected to the container. The suction device is operable to draw air from the container so that the growth medium flows from the reservoir into the container and at least partially immerses the plant.

Description

Technical Field

[0001] The present invention relates to a system and method for cultivating plants, and more particularly to a system and method for supplying a growth medium to plants in a container for propagation. The present invention has been mainly developed for use in cultivating plants under plant tissue culture, and will be mainly described in this context. However, it will be understood that the present invention is not limited to this particular field of use and is potentially applicable to a wide variety of uses including sterile and non-sterile applications, particularly those based on greenhouse and outdoor environments.

Background Art

[0002] The following description of the prior art is intended to present the present invention in an appropriate technical context and to enable its advantages to be properly understood. However, unless specifically stated otherwise, any reference to prior art in this specification should not be construed as an express or implied admission that such technology is widely known or forms part of the common general knowledge in the art.

[0003] Commercial plant tissue culture (PTC) is the clonal micropropagation of plants for the horticultural industry, including ornamental plants for home and landscape, cut flowers, regeneration, horticultural food crops, pharmaceutical crops, and forestry. Historically, PTC has been an expensive method for propagating plants compared to seed and unrooted cutting production (URC) methods, but PTC has found a niche for producing plants that are difficult to propagate and for plants that must be supplied in high health. However, for its cost, PTC has the advantage of producing plants with high health, non-seasonality, increased branching, and overall initial growth vigor.

[0004] PTC is conventionally carried out in a sealed container having a sterilized gel medium that is sterilized before use and placed in a container. The container is usually made of glass or polycarbonate with a polypropylene screw cap and is recyclable or a disposable polypropylene container and a clip-on lid. The drawback of this design is that the medium cannot be replaced or the plants cannot be processed without incurring the associated high labor and time costs and moving to another container.

[0005] Gelling agents can affect plant growth, but most plants that are constantly (even partially) submerged in a liquid medium often develop physiological conditions such as vitrification (excess moisture) that often successfully reduce the plant's growth ability or "deflask" ability. Deflasking is the process of removing the seedlings and clones of the target plants produced and grown in the sterile PTC container due to its environmental safety and extravagance from the container and "introducing" them to standard plant nursery conditions.

[0006] The Temporary Immersion (TI) system successfully overcomes the drawbacks of gelling agents and constant liquid exposure by introducing a liquid medium into the plant chamber several times a day for a few minutes to feed the plants and expose them to plant hormones, then draining and exposing them to lower humidity for air drying, and as a result, the plants do not develop any physiological problems. Most TI systems use air pressure and a complex two-chamber container or a container with many internal parts to push the liquid medium up into the plant chamber from the bottom, thus requiring an air pump and a control device as well as an air filter and a strong seal to maintain the sterilization system.

[0007] The object of the present invention is to overcome one or more of the drawbacks of the prior art, or to substantially improve it, or at least to provide a useful alternative. SUMMARY OF THE INVENTION

[0008] A first aspect of the present invention is a system for supplying a growth medium to a plant, comprising: a container for receiving the plant; a first conduit for fluidly connecting the container to a reservoir having a growth medium; a suction device fluidly connected to the container; and wherein the suction device is operable to draw air from the container, allow the growth medium to flow from the reservoir into the container, and at least partially immerse the plant. In one embodiment, the suction device operates until the growth medium is substantially removed from the reservoir.

[0009] In another embodiment, after the suction device stops operating, the growth medium can flow back into the reservoir. In a further embodiment, the pressure inside the container can be made equal to the pressure outside the container to facilitate the flow of the growth medium back from the container to the reservoir.

[0010] In some embodiments, a second conduit fluidly connects the container to the suction device.

[0011] In some embodiments, the suction device is disposed above, near, or adjacent to the container. In other embodiments, the suction device is disposed on, near, or adjacent to the side or sidewall of the container, preferably the upper side or sidewall. In a further embodiment, the suction device is disposed on, near, or adjacent to the bottom of the container. In embodiments where a second conduit fluidly connects the container to the suction device, the suction device may also be disposed above the container. In one embodiment, the suction device includes a vacuum pump.

[0012] In some embodiments, the reservoir is disposed below the container to facilitate the flow of the growth medium back from the container to the reservoir. In other embodiments, the reservoir is disposed on, near, or adjacent to the bottom of the container to facilitate the flow of the growth medium back from the container to the reservoir.

[0013] ​

[0014] In some embodiments, the container comprises a port that allows gas to flow into the container from outside the container. In one embodiment, the port is fluidly connected to a gas source. In another embodiment, the port is fluidly connected to the air outside the container.

[0015] In some embodiments, the port is associated with a filter for removing contaminants from the gas or air. In other embodiments, the filter sterilizes the gas or air.

[0016] In some embodiments, the port is configured to allow gas or air flow in only one direction. In other embodiments, the port comprises a one-way valve. In further embodiments, the port comprises a two-way valve.

[0017] In some embodiments, the suction device operates for a first predetermined period. In other embodiments, the suction device does not operate for a second predetermined period. In further embodiments, the first determined period is shorter than the second predetermined period.

[0018] In some embodiments, the reservoir is flexible. In one embodiment, the reservoir comprises a flexible bag.

[0019] A second aspect of the present invention is a method of supplying a growth medium to a plant in a container, the method comprising: fluidly connecting the container to a reservoir having a growth medium; fluidly connecting the container to a suction device; applying a suction force to draw air from the container and allow the growth medium to flow from the reservoir into the container such that the plant is at least partially immersed in the growth medium.

[0020] In some embodiments, the suction force is applied until the growth medium is substantially removed from the reservoir.

[0021] In some embodiments, the method includes the step of stopping the suction force and the step of enabling the growth medium to flow back into the reservoir. In other embodiments, the method includes the step of equalizing the pressure inside the container with the pressure outside the container to facilitate the flow of the growth medium back from the container to the reservoir.

[0022] In some embodiments, the suction force is applied over a first predetermined period. In other embodiments, the suction force is stopped over a second predetermined period. In further embodiments, the first determined period is shorter than the second predetermined period.

[0023] In some embodiments, the steps of applying the suction force and stopping the suction force are repeated periodically to introduce the growth medium into the container and draw the growth medium out of the container. In other embodiments, these steps are performed continuously. In further embodiments, these steps are performed intermittently.

[0024] In some embodiments, the method includes the step of applying the suction force at, near, or adjacent to the top of the container. In other embodiments, the method includes the step of applying the suction force at, near, or adjacent to the side or sidewall of the container, preferably the upper side or sidewall.

[0025] In some embodiments, the method includes the step of placing the reservoir below the container to facilitate the flow of the growth medium back from the container to the reservoir. In other embodiments, the method includes the step of placing the reservoir at, near, or adjacent to the bottom of the container.

[0026] In some embodiments, the method includes the step of introducing gas into the container. In one embodiment, the gas is introduced from a port fluidly connected to a gas source. In another embodiment, the gas is introduced from a port fluidly connected to the air outside the container.

[0027] In some embodiments, the method includes filtering a gas or air to remove contaminants. In other embodiments, the method includes sterilizing a gas or air.

[0028] The second aspect can have the same embodiments as the embodiments of the first aspect of the present invention described above, where applicable.

[0029] A third aspect of the present invention is a system for supplying a growth medium to a plant, a container for receiving the plant, a first conduit for fluidly connecting the container to a reservoir having a growth medium, comprising wherein the reservoir is movable between an injection position and a storage position, the reservoir in the injection position allowing the growth medium to flow from the reservoir into the container to at least partially immerse the plant, and the reservoir in the storage position allowing the growth medium to flow from the container into the reservoir, providing a system.

[0030] In some embodiments, the injection position is disposed above the container. In other embodiments, the injection position is disposed above, near, or adjacent to the upper portion of the container. In further embodiments, the injection position is disposed on, near, or adjacent to the side or sidewall of the container, preferably the upper side or sidewall.

[0031] In some embodiments, the storage position is disposed below the container to facilitate the flow of the growth medium returning from the container to the reservoir. In other embodiments, the storage position is disposed at, near, or adjacent to the bottom of the container.

[0032] The third aspect can have the same embodiments as the embodiments of the first and second aspects of the present invention described above, where applicable.

[0033] A fourth aspect of the present invention is a method for supplying a growth medium to a plant in a container, The step of fluidly connecting a container to a reservoir having a growth medium; The step of moving the reservoir to an injection position relative to the container, wherein at the injection position, the reservoir enables the growth medium to flow from the reservoir into the container and at least partially immerse the plant; The step of moving the reservoir to a storage position relative to the container, wherein at the storage position, the reservoir enables the growth medium to flow from the container into the reservoir; A method is provided that includes the above.

[0034] The fourth aspect can have the same embodiments as the embodiments of the third aspect of the present invention described above, where applicable.

[0035] Throughout this specification and the claims, unless the context clearly dictates otherwise, the terms "comprise," "comprising," and the like are to be construed in an inclusive sense rather than an exclusive or exhaustive sense; that is, in the sense of "including, but not limited to."

[0036] Further, as used herein, unless otherwise specified, the use of ordinal adjectives such as "first," "second," "third," etc. to describe a common object merely indicates that different entities of the same object are being referred to, and is not intended to imply that the objects so described must be in any given order, whether in time, space, ranking, or any other way.

Brief Description of the Drawings

[0037] Hereinafter, with reference to the accompanying drawings, preferred embodiments of the present invention will be described by way of example only.

[0038]

Figure 1

Figure 2

Figure 3

Figure 4

Mode for Carrying Out the Invention

[0039] Next, the present invention will be described with reference to the following examples, which should be considered illustrative and non-limiting in all respects. In the figures, corresponding features within the same embodiment or corresponding features common to different embodiments are given the same reference numerals.

[0040] Referring to FIG. 1, a system 100 for cultivating plants according to a preferred embodiment of the present invention includes a container 110 for receiving plants, a first conduit 120, a reservoir 130 having a growth medium 140, a second conduit 150, and a suction device 160. The first conduit 120 fluidly connects the container 110 to the reservoir 130. The second conduit 150 fluidly connects the container 110 to the suction device 160. The suction device 160 is operable to draw air from the container 110 into the second conduit 150, allow the growth medium 140 to flow from the reservoir 130 into the container, and at least partially immerse the plants.

[0041] In this embodiment, the container 110 takes the form of a bioreactor substantially sealed from the external environment, and the first conduit 120 and the second conduit 150 take the form of flexible tubes. In other embodiments, the first conduit 120 and the second conduit 150 may take other forms such as pipes, hoses, etc.

[0042] The suction device 160 in this embodiment is in the form of a vacuum pump disposed above the bioreactor 110. Alternatively, the suction device 160 can be disposed on, near, or adjacent to the upper portion 170 of the bioreactor 110. It will be appreciated that the suction device 160 can also be disposed at other locations on or near the bioreactor 110, such as on the side wall 180, preferably the upper portion of the side wall, or even at the bottom 190 of the bioreactor. In another example, the suction device 160 can be disposed on, near, or adjacent to the side surface, preferably the upper side surface, of the bioreactor 110. Similarly, the suction device 160 can be disposed on, near, or adjacent to the bottom 190. The suction device 160 is preferably disposed at least on, near, or adjacent to the bioreactor 110 and the second flexible tube 150 to ensure that it generates suction most effectively and efficiently within the bioreactor.

[0043] The second conduit or flexible tube 150 is disposed on, near, or adjacent to the upper portion 170, but can be disposed at the same or a similar position as the suction device 160. However, the second flexible tube 150 is preferably disposed such that its opening is at least on, near, or adjacent to the upper portion 170 to ensure that it is not obstructed by plants or other materials (e.g., loose soil, rock, or fallen leaves) when drawing air from the bioreactor 110.

[0044] In some embodiments, the second tube 150 can be omitted and the suction device 160 can be directly connected to the bioreactor 110. In this case, the suction device 160 is directly connected to the bioreactor 110 on, near, or adjacent to the upper portion 170 or the side wall 180, preferably the upper portion of the side wall 180.

[0045] The growth medium 140 is a liquid or fluid medium containing nutrients for promoting the growth and development of plants. In FIG. 1, for the purpose of clarity only, the plants and associated soil are not shown, but they are generally arranged towards the bottom 190 of the bioreactor 110.

[0046] The reservoir 130 can take the form of a flexible container and, in this embodiment, is a flexible bag. Preferably, the flexible bag 130 is disposed below the bioreactor 110, but can be disposed at, near, or adjacent to the bottom 190.

[0047] Also, a port 200 is provided adjacent to the upper part 170 of the bioreactor 110 to allow gas or (ambient) air from outside the bioreactor to flow into the bioreactor. In this embodiment, the port 200 is fluidly connected to the ambient environment outside the bioreactor 110. In this embodiment, the port comprises a two-way valve that allows air / gas to flow in either direction. However, in practice, air / gas flows in one direction, into the bioreactor 110 from the outside, and then out of the bioreactor via the exhaust of the vacuum pump 160. However, in other embodiments, the port 200 is configured to allow fluid to flow into the bioreactor 110 in only one direction and, in one embodiment, will be understood to comprise a one-way valve. This ensures that gas / air does not escape through the port 200 during operation of the vacuum pump 160.

[0048] The filter 210 is operably associated with the port 200 to remove contaminants from the gas or ambient air before they enter the bioreactor 110. In other embodiments, the filter 210 may also sterilize the gas or ambient air as it passes into the bioreactor 110.

[0049] In the initial state shown in FIG. 1, the bioreactor 110 does not contain any of the growth medium 140, and the growth medium 140 is completely stored within the flexible bag 130. Additionally, the air pressure inside and outside the bioreactor 110 is equal.

[0050] Referring to FIG. 2, when transporting or transferring the growth medium 140 from the flexible bag 130 to the bioreactor 110, the vacuum pump 160 is activated. Thereby, the air inside the bioreactor 110 is drawn or flowed through the flexible tube 150 to the vacuum pump 160, where it is discharged to the ambient environment outside the bioreactor 110. As a result, the air pressure inside the bioreactor 110 becomes lower than the air pressure outside the bioreactor 110, and consequently, the liquid growth medium 140 from the flexible bag 130 is drawn into the flexible tube 120 and flows into the bioreactor 110 until the growth medium is substantially removed and the flexible bag 130 is completely collapsed or shrunk.

[0051] External or ambient air is also drawn through the port 200 and the filter 210 to avoid over-depressurization of the bioreactor 110. The filter 210 in this embodiment is a 0.22 micron filter, which removes contaminants and thus sterilizes the ambient air. However, in other embodiments, where sterilization is not required but only a rough filtration of contaminants is needed, filters of various sizes may be used. The entry of ambient air also enriches the air inside the bioreactor 110 with fresh air. Alternatively, the port 200 can be fluidly connected to a gas source (not shown) to supplement or supply gas to the bioreactor 110 to promote plant growth or development. For example, the port 200 can be fluidly connected to a CO2 tank or other gas reservoir to supply a CO2-enriched gas or other gas mixture to the bioreactor 110.

[0052] When the growth medium 140 is substantially removed from the flexible bag 130, the vacuum pump 160 is turned off. Alternatively, the vacuum pump 160 stops operating when the growth medium 140 is substantially supplied into the bioreactor 110 and at least partially or completely immerses the plants disposed at or near the bottom 190 for a sufficient period of time. In a further alternative, before turning off, the vacuum pump 160 gradually reduces its suction force to optimize the residence time of the growth medium 140 with the plants.

[0053] As best shown in FIG. 3, after the vacuum pump 160 stops operating, the growth medium 140 can gradually flow back into the flexible bag 130 through the flexible tube 120. Since the vacuum pump 160 no longer generates a suction force, the pressure inside the bioreactor 110 can gradually increase until it equals the pressure outside the bioreactor 110. This gradual increase in pressure is facilitated by the port 200 that allows ambient air to enter the bioreactor 110. As a result, the increased pressure promotes the flow of the growth medium 140 back from the bioreactor 110 to the flexible bag 130.

[0054] In addition, due to the position of the flexible bag 130 under the bioreactor 110, gravity causes the liquid growth medium 140 to be discharged and returned into the flexible bag 130. However, it will be understood that this effect can be similarly achieved by disposing the flexible bag 130 at, near, or adjacent to the bottom 190 of the bioreactor 110.

[0055] This cycle of applying suction to draw the growth medium 140 into the bioreactor 110 to partially immerse the plants and then stopping the suction to return the growth medium to the flexible bag 130 can be repeated continuously or intermittently. Thus, the system 100 can be used to promote the growth of plants in the bioreactor 110 throughout the life cycle of the plants until the plants are ready to be removed.

[0056] Generally, the suction force is applied for a predetermined period of the first or operating state to draw the growth medium 140 into the bioreactor 110 and at least partially immerse the plant. This predetermined period of the first or operating state is typically less than the predetermined period of the second or non-operating state, during which there is no suction force and the growth medium 140 can be drained back into the flexible bag 130 for storage and / or there is no need for the growth medium to be supplied to immerse the plant in the bioreactor 110.

[0057] System 100 allows the liquid growth medium 140 to be periodically introduced into the bioreactor 110 to promote the growth of the plants therein without constantly submerging them, thus avoiding the occurrence of physiological conditions such as vitrification (excess moisture) that would reduce the growth ability or flushing ability of the plants. Further, unlike the prior art that uses complex systems with complex containers having intricate structures, air pumps, control devices, and filters, system 100 provides a convenient and simpler mechanism for adding and removing the growth medium 140 from the bioreactor 110.

[0058] Referring to FIG. 4, another embodiment of the present invention is shown, where system 300 is manually operated when the vacuum pump 160 is absent or not available. In this embodiment, the flexible bag 130 is disposed above the bioreactor 110 such that the growth medium 140 flows down through the flexible tube 120 into the bioreactor solely by gravity. As a result, the air pressure within the bioreactor 110 increases, whereby air is discharged from the bioreactor 110 through the port 200 via the filter 210.

[0059] When the growth medium 140 is supplied to the plants in the bioreactor 110 and retained for an appropriate period of time, the flexible bag 130 is moved or repositioned below the bioreactor 110 such that the growth medium 140 flows from the bioreactor into the flexible bag via the flexible tube 120 under gravity. At the same time, air is drawn back into the bioreactor 110 through the port 200 and the filter 210 to equalize the air pressure inside the bioreactor 110 with the ambient air pressure outside the bioreactor.

[0060] Accordingly, this embodiment, similar to the embodiments of FIGS. 1 - 3, can at least partially immerse the plants in the bioreactor 110 in the liquid growth medium 140. This system 300 can achieve the same effects as the system 110, but requires manual intervention and thus increases labor costs. Accordingly, the embodiments of FIGS. 1 - 3 are a more preferred way to implement the present invention in commercial applications.

[0061] Furthermore, it will be understood that any of the features in the preferred embodiments of the present invention can be combined together and are not necessarily applied separately from each other. For example, the reservoir or flexible bag 130 of FIGS. 1 - 3 may also be movable as shown in FIG. 4 to enable both automatic and manual operation of the system 100. Similar combinations of two or more features from the above-described embodiments or preferred forms of the present invention can be readily made by those skilled in the art.

[0062] By providing a suction device and a reservoir, or by making the reservoir movable relative to the container, the present invention provides the advantage of being able to deliver and return the growth medium to a plant growth container that is convenient, simple, and easy to use, particularly when compared to prior art TI systems. In one embodiment, this advantage is further enhanced by providing a port that allows the passage of gas or air and a filter for controlling the air pressure within the container. All of these advantages of the present invention result in a TI system that uses fewer parts and has a simpler structure, resulting in lower capital costs, lower maintenance costs, and greater convenience. In all of these respects, the present invention represents a practical and commercially important improvement over the prior art.

[0063] Although the present invention has been described with reference to specific examples, those skilled in the art will understand that the present invention can be embodied in many other forms.

Claims

1. A system for supplying a growth medium to a plant, comprising: a container for receiving the plant; a first conduit for fluidly connecting the container to a reservoir having the growth medium; a suction device fluidly connected to the container; wherein the suction device is operable to draw air from the container, allow the growth medium to flow from the reservoir into the container, and at least partially immerse the plant. The system.

2. The system according to claim 1, wherein the suction device operates until the growth medium is substantially removed from the reservoir.

3. The system according to claim 1 or 2, wherein after the suction device stops operating, the growth medium can flow back into the reservoir.

4. The system according to claim 3, wherein the pressure inside the container can be made equal to the pressure outside the container to facilitate the flow of the growth medium back from the container to the reservoir.

5. The system according to any one of claims 1 to 4, wherein a second conduit fluidly connects the container to the suction device.

6. The system according to any one of claims 1 to 5, wherein the suction device is disposed at, near, or adjacent to the top, side, or bottom of the container.

7. The system according to any one of claims 1 to 6, wherein the reservoir is disposed at, near, or adjacent to the bottom of the container to facilitate the flow of the growth medium back from the container to the reservoir.

8. The system according to any one of claims 1 to 7, wherein the container comprises a port that allows gas to flow into the container from outside the container.

9. The system according to claim 8, wherein the port is fluidly connected to a gas source.

10. The system according to claim 8, wherein the port is fluidly connected to the air outside the container.

11. The system according to any one of claims 8 to 10, wherein the port is associated with a filter for removing contaminants from the gas or air.

12. The system according to claim 11, wherein the filter sterilizes the gas or air entering the container.

13. The system according to any one of claims 1 to 12, wherein the reservoir is flexible. **Claim 14** A method for supplying a growth medium to a plant in a container, comprising: fluidly connecting the container to a reservoir having the growth medium; fluidly connecting the container to a suction device; applying a suction force to draw air from the container and allow the growth medium to flow from the reservoir into the container so that the plant is at least partially immersed in the growth medium. A method as described above. **Claim 15** The method according to claim 14, wherein the suction force is applied until the growth medium is substantially removed from the reservoir. **Claim 16** The method according to claim 14 or 15, comprising stopping the suction force and allowing the growth medium to flow back into the reservoir. **Claim 17** The method according to claim 15 or 16, wherein the steps of applying the suction force and stopping the suction force are repeated continuously or intermittently to introduce the growth medium into the container and withdraw the growth medium from the container. **Claim 18** The method according to any one of claims 14 to 17, comprising equalizing the pressure inside the container with the pressure outside the container to facilitate the flow of the growth medium from the container back to the reservoir. **Claim 19** The method according to any one of claims 14 to 18, comprising disposing the reservoir at, near, or adjacent to the bottom of the container to facilitate the flow of the growth medium from the container back to the reservoir. **Claim 20** The method according to any one of claims 14 to 19, comprising introducing a gas into the container. **Claim 21** The method according to claim 20, wherein the gas is introduced from a port fluidly connected to a gas source. **Claim 22** The method according to claim 20, wherein the gas is introduced from a port fluidly connected to the air outside the container. **Claim 23** The method according to any one of claims 20 to 22, comprising filtering the gas or air to remove contaminants. **Claim 24** The method according to any one of claims 20 to 22, comprising sterilizing the gas or air. **Claim 25** The method according to any one of claims 14 to 24, comprising the step of applying the suction force above the container, near the upper part of the container, or adjacent to the upper part of the container.

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