WO2019192737A1

WO2019192737A1 - Apparatus and method for transplanting seedlings

Info

Publication number: WO2019192737A1
Application number: PCT/EP2018/058944
Authority: WO
Inventors: Wim VAN DER EL; Wim Struijk
Original assignee: I.G. Specials B.V.
Priority date: 2018-04-06
Filing date: 2018-04-06
Publication date: 2019-10-10
Also published as: EP3772883A1

Abstract

There is discussed a transplantation head for transplanting a seedling from a seedling container to a plot of growth medium. The transplantation head collects the seedlings and plants them into a flowerbed using convergent members that can penetrate the surface of the flowerbed.

Description

l

APPARATUS AND METHOD FOR TRANSPLANTING SEEDLINGS FI ELD OF TH E INVENTION

The present invention relates to an apparatus and method for transplanting seedlings from a seedling container to a plot of growth medium. Furthermore, the invention relates to a transplantation head and a series of transplantation heads for transplanting seedlings from a seedling container to a plot of growth medium. The present invention also relates to a seedling container supply system for use with an apparatus for transplanting a seedling from a seedling container to a plot of growth medium.

BACKG ROUN D OF TH E INVENTION

In many horticultural and agricultural applications, it is often the case that plant material units are transplanted multiple times, for example to improve crop yields. For example, the seed of many plant varieties is often first sprouted to seedlings in an initial growth medium and holder in a nursery, and the seedlings are then subsequently transplanted to large plots of growth medium such as soil flowerbeds in greenhouses or hothouses, for continued growth. The larger plots allow the seedlings to be more spaced from one another, and have deeper ground, so that growth can continue without competition from neighbouring plants, and root systems can extend. The ambient conditions of such a plot may also be more conducive to continued growth than those of a nursery.

Transplanting refers to extracting the combination of a seedling plant and plug of growth medium and seedling root mass, from a seeding medium and planting the plug in a different, typically much larger, plot of growth medium for continued development of the plant.

Transplanting of seedlings is currently typically done manually. However, manual transplantation of seedlings raises a number of drawbacks. For example, the work is arduous, not least because it is often done in greenhouses operating at high temperatures (e.g. 28 degrees Celsius and above) with air compositions (oxygen, carbon dioxide, humidity and nitrogen) that may differ from ambient compositions, in order to advance plant growth, and often requires work close to ground-level. Furthermore, there may be a lack of consistency in how individual workers plant seedlings. As a result, the propagation success rate of manually planted seedlings can be negatively affected. In addition, manual handling of the plants can lead to damage of the seedlings and possibly to the spread of diseases. Automatization of seedlings transplantation is thus desirable.

Planting machines for transplanting plants from pot to pot are known from, for example, patent application WO 2014/207073 A1 . Patent application WO 2016/1 16402 A1 describes an apparatus for automated transplanting of seedlings from first seedling trays into empty or indented cavities within plant trays, in order to provide greater growing space for the transplanted seedlings. However, these planting machines are not arranged for transplantation of seedlings from, for example, a container comprising seedlings into a plot of growth medium such as a flowerbed.

Another example of an apparatus for transplanting plants from containers with small containers to large containers is also known from US2004/00201 10, which transplants a plant unit into a void in a larger pot.

Dutch patent publication 8802151 discusses a further example of an transplanting element for collecting a seedling in a plug of growth medium. The transplanting element is again suitable to transplant into a premade void.

Furthermore, the presence of components upon flower beds within greenhouses, such as grids, water supplies or warming elements, may pose barriers towards automatization. For instance, a tractor with integrated planting machine could damage such components. Furthermore, automated transplanting of the seedlings prior to providing a grid may result in difficulties of accurately aligning the grid over the transplanted seedlings, also because the plot may not be perfectly planar or horizontal throughout over its entire area.

The present invention is concerned with answering one or more of the above matters. SUMMARY OF THE INVENTION

In a first aspect of the present invention there is provided a transplantation head for transplanting a seedling, from a seedling container to a plot of growth medium, the transplantation head comprising at least two elongate members, wherein the elongate members are arranged to assume at least the following configurations: a pre-collection configuration wherein the elongate members are in an open arrangement, for insertion adjacent a plug of growth medium about a seedling’s root mass; a transfer configuration wherein the elongate members are in a downwardly convergent arrangement to grasp the plug of growth medium during transplantation, the downwardly convergent elongate members forming an apex for penetrating said plot of growth medium; a withdrawal configuration, wherein the elongate members are arranged to withdraw from said plot of growth medium along a plug-plot interface surface.

The plot to which the seedling is transplanted may be a plantbed, a flowerbed, a vegetable patch or row, may be of any shape, longitudinal, square, polygonal, a row or a bed; or an open or covered field. Preferably at least one horizontal dimension of the plot is 5 metres or greater, preferably 10 metres or greater.

The plug-plot interface is the boundary line between the plug of seedling growth medium, and the plot of growth medium.

Seedling containers may be any suitable containers, including plant pots or seedling trays. Preferably the seedling container is a seedling tray comprising cavities for containing seedlings.

The distal ends of the elongate members may substantially be as broad or as wide as a plug of growth medium in which the transplanted seedling is rooted. The plug is in this manner firmly collected and supported for transport and planting. For example, the elongate members may have grasping surface that are at least 50%, of the breadth or width of the plug, more preferably at least 70%, at least 80%, and still more preferably at least 90%. The elongate members may converge to an apex having an internal angle of from 10° to 60°, preferably from 15° to 50°, and most preferably a is from 15° to 45°. More specifically, the elongate members during at least a part of transplantation are converged to an apex having an internal angle within 10° of a, wherein

wherein

x = a width of a seedling containing cavity in the seedling container

z = a height of a seedling containing cavity in the seedling container

The apex may take the form of a ridge or edge, or a point, suitable to penetrate the plot’s upper surface.

The transplantation head further may comprise an abutment member that is arranged to push the elongate members apart in order to return the elongate members from the withdrawal configuration to the pre-collection configuration. The abutment member may comprise a ram for holding or steadying the plug of growth medium against withdrawal forces associated with withdrawal of the elongate members from the plot, such that the plug is not displaced from its planted position during withdrawal of the elongate members. Withdrawal refers to retraction or pulling-out of the elongate members.

The elongate members of the transplantation head may comprise a first plate and a second plate that are substantially parallel relative to one another in the pre- collection configuration, and wherein distal tips of each plate touch in the transfer configuration. Furthermore, the distal tips may in the pre-collection configuration may even be pressed against one another. The plates may take the form of blades or slices, as appropriate to the seedling plugs being handled, and the shape of apex to be formed.

The transplantation head according to the present invention may further comprise a penetration depth controller to limit the depth of penetration of the elongated members into the plot of growth medium, preferably wherein the depth of penetration is within 70% of the height z of the plug of growth medium, preferably 60% and more preferably 50%of the height z of the plug of growth medium. Preferably the depth of penetration is from 1 to 1.7 times the height of the plug, preferably from 1 to 1 .5 times the height of the plug.

The penetration depth controller may comprise, but is not limited to, a sensor for measuring the depth of penetration of the elongate members, or related elements, into the plot. Alternatively, the penetration depth controller comprises a stop, such as a mechanical buffer, adapted to limit the penetration of the elongate members when the abutment-member contacts a grid or a pipeline for gas or liquid supply, upon said plot.

The transplantation head may comprise a sliding system comprising a holding member and a sliding body, wherein the sliding body is in fixed connection to the elongated members and wherein the sliding body can slide over the holding member.

The stop may be in fixed connection to the holding member. The stop may be made from plastic, stainless steel, aluminum or any other type of metal or alloy. Preferably, the stop is made from a light material, and is shaped to have a large surface that interacts with a grid or a pipeline that is provided over the plot, while limiting the overall volume of the stop. The stop may have be prism shaped.

Furthermore, the elongated members may comprise interference members that physically engage the stop in the transfer configuration, such that a distal tip of each elongated member is forced to converge and preferably touch the other, and wherein the stop is in fixed connection to the holding member. Furthermore, the distal tips may in the pre-collection configuration be pressed against one another. The interference members may be made from plastic, stainless steel, aluminum or any other type of metal or alloy.

The transplantation head according to the present invention may be used for the transplantation of seedling of any plant material. The transplantation head according to the present invention is in particular compatible for transplantation of Lisianthus seedlings. The transplantation head according to the present invention is also compatible for transplantation of many other flower seedlings, such as chrysanthemums, but also seedlings from vegetables and seedlings from fruits.

In a further aspect of the present invention there is provided a seedling transplantation tool comprising a plurality of transplantation heads, wherein one or more of the transplantation heads is in accordance with the transplantation head according to the first aspect of the present invention.

The transplantation heads of the transplantation tool may be spaced from one another, and the spacing of the transplantation heads may be adjustable during use. The spacing can be adapted to a grid that is provided over the plot, and can be set via a computer system.

In yet another further aspect of the present invention, there is provided for a seedling transplantation apparatus comprising: a seedling transplantation tool comprising a plurality of transplantation heads, wherein one or more of the transplantation heads is in accordance with the transplantation head according to the first aspect of the present invention; a robotic carrier, preferably a robot arm or gantry, for carrying the transplantation tool.

In still a further aspect of the present invention there is provided for a seedling transplantation apparatus comprising: a transplantation head according to the first aspect of the present invention; a robotic carrier, preferably a robot arm or gantry, for carrying the transplantation head.

The seedling transplantation apparatus may comprise a supply bridge for storage of further seedling containers. The seedling transplantation apparatus may comprise a computer system for at least inserting and adjusting operating settings of the robot arm and/or transplantation head.

The seedling transplantation apparatus may comprise at least one walking bridge for operators to access the apparatus. The seedling transplantation apparatus may be further provided with a side bridge 107 and a rear bridge 108. The side bridge 107 may be in connection to the walking bridge 106 and to the rear bridge 108. Human operators may access the plot of growth medium via the rear bridge 108.

The seedling transplantation apparatus may comprise a safety shield to protect operators to have direct interaction with the robot arm and transplantation head.

The seedling transplantation apparatus may comprise a detection system arranged to detect the location of a grid that is provided above the plot of growth medium. The detection system may comprise a camera configured to recognize or identify the grid 101 by means of pattern recognition. Alternatives to a camera system include sensors for determining the grid position, for example contact or contactless sensors, such as pressure sensors, ultrasound, or metal sensors (where the grid comprises metal).

The transplantation apparatus may be arranged to move over the plot of growth medium. The transplantation apparatus thereby may comprise wheels for moving over the plot of growth medium. Said wheels may be arranged to ride over pipelines for gas or liquid supply that are provided over the plot of growth medium. The wheels 119 may be grooved, such that the wheels 1 19 are adapted to stably ride over the pipelines 103. The apparatus may further comprise an alarm system for warning operators for movement of the apparatus.

The transplantation apparatus may further comprise multiple robot arms or gantries, each robot arm or gantry comprising at least one further transplantation head wherein one or more of these transplantation heads are arranged according to the first aspect of the invention. In case the robot arm or gantry carries multiple transplantation heads, the transplantation heads may be spaced from one another, wherein said spacing is adjustable. Said spacing may be adjustable during use. The spacing can be adapted to a grid that is provided over the plot, and can be set via the computer system of the transplantation apparatus.

In yet another aspect of the invention there is provided a seedling container supply system for use with an apparatus for transplanting a seedling from a seedling container to a plot of growth medium, comprising: a seedling container supply device to transfer the seedling container containing seedlings to an operating position at which seedlings are being grasped for transplantation; a locking device to lock a row of the seedling container with seedlings adjacent to a row of the seedling container with seedlings that are being grasped; a seedling container retrieval device to transfer the seedling container to a storage position once the seedling container is empty.

The seedling container supply device may comprise at least one pin that is arranged to drag the container to the operating position, wherein the pin is coupled to a bottom pinhole that is provided in the container. The locking device may comprise at least one pin. The seedling container retrieval device may comprise a pushing unit that pushes the container to an intermediate position, said seedling container retrieval device further comprising at least one further pushing unit that is arranged to push the container to the storage position. The storage position may comprise an elevator system for stacking empty containers.

In still another aspect of the invention there is provided for a seedling transplantation apparatus according to the present invention, wherein the seedling transplantation apparatus comprises a seedling container supply system according to a further aspect of the invention as described above.

In yet another aspect of the invention, there is provided for a method of transplanting a seedling from a seedling container to a plot of growth medium, the method comprising: bringing elongate members towards the seedling in the seedling container; inserting the elongate members adjacent a plug of growth medium enclosing seedling root mass, while the elongate members are in an open arrangement; grasping the seedling with the elongate members, wherein the elongate members are provided in a downwardly convergent arrangement to grasp the plug of growth medium during transplantation; penetrating the plot of growth medium with the elongate members, wherein the elongate members form an apex; withdrawing the elongate members from the plot of growth medium, wherein the elongate members are arranged to withdraw along a plug-plot interface surface. Said method may use a transplantation head according to the first aspect of the present invention. Other features and advantages of the present invention will be apparent from the detailed description that follows.

BRIEF DESCRIPTION OF THE ACCOMPANYING DRAWINGS

The present invention is described with respect to particular exemplary embodiments thereof and reference is accordingly made to the drawings in which:

Figures 1 A-C show different views of a seedling transplantation apparatus;

Figures 2A-D show dimensions of exemplary seedlings with a plug of growth medium;

Figures 3A-G show different views of a transplantation head for transplanting a seedling;

Figures 4A-B show the front side and rear side respectively of a transplantation tool comprising a plurality of transplantation heads;

Figure 5A shows a transplantation tool adjacent to seedlings in a seedling container;

Figure 5B shows a transplantation tool after it has transplanted a row of seedlings in a plot of growth medium;

Figure 6 shows a flow diagram for a method of transplanting a seedling from a seedling container to a plot of growth medium;

Figures 7A-D show manual transplanting of a seedling;

Figure 8A-F show transplanting of a seedling according to the present invention; Figures 8G-8I show a transplantation head in several configurations;

Figures 9A-B show different perspectives of a seedling container supply system;

Figure 9C-D show different perspectives of an exemplary seedling container.

DETAILED DESCRIPTION

It will be appreciated that for simplicity and clarity of illustration, where considered appropriate, reference numerals may be repeated among the figures to indicated corresponding or analogous elements or steps. In addition, numerous specific details are set forth in order to provide a thorough understanding of the embodiments described herein. However, it will be understood by those of ordinary skill in the art that the embodiments described herein may be practiced without these specific details. Furthermore, this description is not to be considered as limiting the scope of the embodiments described herein in any way, but rather as merely describing the implementation of the various embodiments described herein.

Reference is made to Figures 1A-C. Figure 1A shows a front-side of an apparatus 100 for transplanting seedlings, in a working situation above a plot 101 . Apparatus 100 is arranged for transplanting seedlings of any kind of plants, including but not limited to flowering plants such as Lisianthus, Chrysanthemums, etcetera, but also seedlings from vegetables like potatoes and carrots and seedlings from fruits.

The apparatus 100 is shown above a plot of growth medium 101 , in the illustrated case a flowerbed comprising a number of substantially parallel rows. The plot of growth medium 101 may comprise soil, or any other type of grow medium suitable for plant material.

When planting seedlings into the plot, sufficient growing space for each seedling should be provided such that the roots of neighboring seedlings will not interfere, while the stems and leaves of the seedlings will not get intertwined above the ground while the seedlings grow. It is therefore common to provide a grid 102 over the surface of the plot 101. Accordingly, in each cell of the grid 102 one or two seedlings are transplanted. The grid 102 may for example have the structure of a rectangular, such as a square, grid, and may thereby divide the plot 101 into square areas sized to accommodate one or two seedlings. As the seedlings grow, the grid is raised in height above the ground such that the seedlings are supported while they grow and remain separated from one another.

Apparatus 100 may comprise a detection system, which is arranged to detect the location of the grid 101 or parts thereof above the plot. The detection system may comprise a camera configured to recognize or identify the grid 101 by means of pattern recognition.

The plot 101 may further be provided with one or more pipelines 103 for gas and/or liquid supply. Some pipelines 103 may transport water, optionally with nutrient additives, to the seedlings. Other pipelines 103 may transfer gas such as carbon dioxide, or carbon dioxide enriched air. Some pipelines 103 may transfer heated gas or liquid and may serve as a heat source for the seedlings. The grid 102 is preferably in thermal contact with the heated pipelines 103, such that the grid 102 may act as a heat distributor to or above the plot 101.

The apparatus 100 may be provided with a supply bridge 104 for supplying containers of seedlings. Each container may for instance comprise multiple seedlings that are provided in separate cavities in a container. Multiple containers may be supplied and stored upon supply bridge 104. The supply bridge 104 may comprise a slide 105, allowing a vehicle to access the supply bridge 104, for transportation of containers carrying the seedlings.

The apparatus 100 may also comprise further bridges, for instance one or multiple walking bridges 106. The walking bridge 106 is arranged such that human operators can access several operating parts of the apparatus 100. For example, a walking bridge 106 may be provided adjacent to the supply bridge, allowing human operators to access the containers carrying the seedlings. The apparatus may be further provided with a side bridge 107 and a rear bridge 108. The side bridge 107 may be in connection to the walking bridge 106 and to the rear bridge 108. Human operators may access the plot of growth medium via the rear bridge 108. An advantage of providing for a rear bridge 108 is that a human operator can correctly transplant seedlings in the event a seedling is misplanted. Figure 1 B shows another perspective of the apparatus 100, showing the rear side of apparatus 100 and the rear bridge 108 in more detail.

The apparatus 100 comprises a robotic carrier, in the illustrated device a robot arm 109 but a gantry may also be used. The robot arm 109 carries one or multiple transplantation heads 1 10 for transplanting seedlings. In the embodiment of Figures 1A-C, the apparatus comprises three robot arms 109, wherein each robot arm 109 carries a transplantation tool carrying multiple transplantation heads 1 10. The skilled person however understands that the apparatus 100 may comprise any number of robot arms 109 or gantries, wherein each robot arm 109 may carry any practical number of transplantation heads 1 10.

A closer view of the robot arm 109 with transplantation heads 1 10 is shown in Figure 1 C. The transplantation heads 1 10 may be pneumatically operated, but servo operation and hydraulic operation may also be possible. Pressured gas for pneumatic operation may be provided by a hose reel 1 1 1 that is provided on apparatus 100.

Apparatus 100 may further comprise a safety shield 1 12 provided in a housing 1 13 to protect human operators from moving parts. Apparatus 100 may further be provided with an on-board computer system 1 14. Via computer system 1 14, operators may insert several settings of apparatus 100, for instance the operating settings of the robot arm 109 and the transplantation heads 1 10.

Apparatus 100 may further comprise a seedling container supply system 1 15. The supply system 1 15 of apparatus 100 is arranged for automatic transportation of empty seedling containers from an operating side 1 16 to a storage side 1 17. Details of the supply system 1 15 will be explained later. Apparatus 100 may be provided on a platform 1 18, such as a trolley, having wheels 119. In this way, apparatus 100 may travel over the plot 101 , in order to transplant seedlings at different locations. Once a complete row of seedlings are transplanted into the plot 101 , the apparatus 100 travels further for transplanting the next row of seedlings. For plots 101 that are provided with pipelines 103, such as that illustrated, the wheels 1 19 of apparatus 100 may ride over these pipelines 103, and the pipelines 103 may serve thereby as rails. The wheels 1 19 may be grooved, such that the wheels 1 19 are adapted to stably ride over the pipelines 103.

The supply system 1 15 may comprise one or more sensors (not shown) for sensing the presence of a container with seedlings. Registration of the containers with seedlings prevents that apparatus 100 is operating while there are no seedlings present for transplantation. In case no container with seedling is supplied on time into the supply system 1 15 while the apparatus 100 is operating, a warning signal is provided, warning the operator to supply a seedling container in the supply system 115. A warning signal can be an audible alarm, or a visible alarm, or any other signal that could warn operators. Furthermore, apparatus 100 may be further equipped with a similar alarm system, warning the operator that movement of apparatus 100 is about to commence. Warning signals for different events may be different and distinguishable from one another.

Reference is made to Figures 2A-D. Figure 2A shows a seedling 200 with a plug of growth medium 201 , for example soil. The plug of growth medium 201 may have a rectangular cuboid shape, as illustrated in Figure 2A. The exemplary plug 201 according to Figure 2A has a width (a), a breadth (b) and a height (c). These dimensions (a), (b) and (c) may be equal to one another. Alternatively, the breadth may be the greater dimension. Preferably the width (a) is the longer dimension in rectangular cuboid plugs. Width (a) and breadth (b) may range between 8 mm and 50 mm. Height (c) may range between 20 mm and 50 mm. The dimensions of the plug 201 may however vary, dependent on the plant type.

Figure 2B shows the same plug of growth medium 201 according to Figure 2A, but the bottom part of the plug 201 is squeezed such that plug 201 has obtained a wedged shape. Figures 2C and 2D provide exemplary dimensions of such a squeezed plug 201 , wherein a top view and a front view of Figure 2B is shown respectively.

The plug according to Figures 2B-D may have a breadth (x) ranging between 8 mm and 50 mm, and a width (y) may range between 8 mm and 50 mm as well. The width and breadth may be equal, or either the width of the breadth may be the longer dimension. The height (z) of plug 201 may range between 20 mm and 50 mm. The internal angle (a) may be determined by the equation (1 ) below:

The skilled person however, will understand that the plug of growth medium may have a different shape, but may have a volume with similar magnitude.

Reference is made to Figures 3A-G showing a transplantation head 203 in more detail. The transplantation head 203 comprises elongate members 204. The transplantation head may assume multiple configurations. Figures 3A, 3E and 3G show a transplantation head in a pre-collection configuration, in which the elongate members 204 are in an open arrangement, this is, they are oriented, preferably substantially vertically, to be plunged along edges of a plug of growth medium held in a cavity of a seedling tray. Figures 3B, 3D and 3F, show the transplantation head 203 in a transfer configuration, in which the elongate members 204 converge downwardly to form an apex (A) that can penetrate the plot 101. Penetration includes piercing the plot of growth medium’s upper surface, and inserting or implanting the seedling plug.

In the exemplary embodiment of Figures 3A-G, the elongate members comprise blade-like plates. The plates may comprise or consist of plastic, stainless steel, aluminum or any other type of metal or alloy, or any other suitably stiff material. Preferably, the elongate members 204 are made from a resilient material. A resilient material facilitates the elongate members 204 to penetrate the plot in the transfer configuration. Although the exemplary embodiment of Figures 3A-G are limited to two elongate members 204, the transplantation head 203 may comprise any plurality of elongate members 204, that can transition from an open configuration, in which each elongate member 204 is positioned to be plunged along the sides of a plug of growth medium held in a cavity of a seedling tray; and a closed configuration in which the elongate members 204 converge downwardly to form an apex for penetration of the growth medium. For example, 3, 4, 5 or 6 elongate members may be provided. The elongate members 204 may also be shaped to collect and converge upon any shape of seedling plug, for example for cylindrical plugs, the elongate members 204 may be curved, and interweave over one another to form a cone or similar in the transfer configuration.

Preferably, each of the elongate members is moveable to transition between an open and convergent position, however, it is also possible that one or more of the elongate members 204 is fixed relative to the transplantation head, and that one or more other elongate members 204 are moveable to converge upon the one or more fixed elongate members 204, forming the apex. The latter may result in a non- symmetric wedge shape for penetration of the plot 101 , which may or may not be less preferred.

The convergent elongate members during at least a part of transplantation are converged preferably converged with an apex having an internal angle within 10° of a defined above, preferably within 5°, and most preferably substantially a. Preferably a is from 10° to 80°, preferably from 15° to 70°, and most preferably a is from 20° to 55°.

The pre-collection configuration of the transplantation head is shown in figures 3A, 3E and 3G, wherein the elongate members 204 are in an open arrangement. For instance, in the exemplary embodiment of Figure 3A, the elongate members 204 are substantially parallel to one another. In this way, the elongate members 204 are in a configuration to accept a seedling 200 between the elongate members 204.

The transplantation head 203 may thus be used within apparatus 100, for transplanting a seedling from a seedling container to a plot of growth medium 101 . Accordingly, a transplantation head 203 is arranged near a container of seedlings. The elongate members 204 are then arranged adjacent to the seedling 200 with a plug of growth medium 201 , such that the elongate members 204 enclose the seedling root mass. That is, to collect a seedling 200 in a plug of growth medium 201 from a cavity in a seedling tray, the elongate members 204 are plunged downwardly along the side interface of the seedling tray cavity and growth medium 204. This is shown in Figure 3C.

The elongate members 204, during or after insertion, are pivoted into the convergent configuration for seedling 200 transfer as shown in Figures 3B, 3D and 3F. Figure 3B shows the transplantation head 203 in the transfer configuration. In this configuration, the elongate members 204 are in a downwardly convergent arrangement forming an apex (A). The elongate members 204 thus grip the plug 201 and squeeze it to a wedge-shape (e.g. a shape according to Figure 2B). The growth medium, typically soil or an equivalent thereof, is flexible and preferably porous, such as a flexible foam, and can be squeezed by the converging elongate members 204. The plug 201 is thus formed into a wedge shape, with elongate members 204 about two opposing sides, and supporting the plug 201 from below. The plug 201 can then be withdrawn from the seedling tray and transported to the plot 101.

In the exemplary embodiments of Figures 3B, 3D and 3F, the end tips or distal tips of the elongate members 204 are pressed against one another in the transfer configuration forming a relatively sharp ridge, however, the skilled person will understand that , although preferred, it is not necessary for the elongate member 204 to make contact, and the formed wedge shape may be more blunt or slightly open, so long the plug can be pushed into the plot 101 without being dislodged from the transplantation head 203 during the action of penetration.

The elongate members 204 in the transfer configuration support the seedling 200 for transport from the seedling container to the plot of growth medium 101. The plug 201 is thereby preferably supported by the elongate members, such that the plug 201 is supported during transportation, e.g. such that the plug 201 does not fall apart or fall out of the transplantation head 203. Once the transplantation head 203 with seedling 200 is above the plot 101 , the elongate members 204 penetrate the plot’s upper surface by moving the transplantation head 203 towards the plot 101 , pushing the plug 201 completely or partially into the plot 101. The convergent configuration of the elongate members 204, forming an apex (A), can easily penetrate the plot 101 . This is shown in Figure 8D.

Once the convergent elongate members 204 have penetrated the plot 101 to an appropriate depth for seedling growth (typically when the plug 201 is substantially level with the plot surface, that is a depth equal to the height z of the plug), the elongate members 204 are brought into a withdrawal configuration. In the withdrawal configuration, the elongate members 204 are withdraw from the plot of growth medium 101 along the formed plug-plot interface surface 501 (Figure 8E). The elongate members 204 are thereby brought into a configuration, that the elongate members 204 can freely glide along the plug-plot interface 501 , preferably providing minimal force on the plug 201 and not disturbing the surrounding plot growth medium. This reduces or avoids airgaps at the plug-plot interface 501 after withdrawal of the elongate members 204 from the plot 101. A close fit of the plug 201 with the plug-plot interface 501 may further result due to resilient re-expansion of the growth medium of the plug 201 and plot 101 against one another.

Figure 6 shows a flow diagram in which the above discussed method of transplanting a seedling from a seedling container to a plot of growth medium is presented.

Figures 3F and 3G show a front view of the transplantation head 203 with elongate members 204 in the pre-collection configuration and the transfer configuration respectively. The transplantation head 203 further comprises a sliding system comprising a holding member 205 and a sliding body 206. The holding member 205 and sliding body 206 may be made from plastic, stainless steel, aluminum or any other type of metal or alloy. The holding member 205 and sliding body 206 are arranged such that the sliding body 206 can slide up and down along the holding member 205. The holding member thereby may comprise grooves and the sliding body 206 may comprise sliding units such as wheels, such that the sliding body 206 can smoothly slide over sliding body 206. The sliding body 206 may comprise holes 206A. Holes 206A may thereby facilitate easy cleaning of the transplantation head 203 with water or pressurized air. For example, the holding member 205 and the sliding body 206 become dirty and covered with soil after a couple of cycles of transplanting seedlings. Quick cleaning of the transplantation head 203 is thereby important, for good functioning of the transplantation head, while maintaining a high throughput of transplanted seedlings. Furthermore, the sliding body 206 is in fixed connection with the elongate members 204. Thus, when the sliding body moves upwardly, the elongate members 204 move along with the sliding body. Furthermore, the transplantation head 203 may further comprise an abutment member 207 that is arranged to push the elongate members 204 apart in order to pivot the elongate members 204 between the withdrawal configuration and the pre-collection configuration. The abutment member 207 may comprise a ram 208 for holding or steadying the plug of growth medium 201 against withdrawal forces associated with withdrawal of the elongate members 204 from the plot 101 , such that the plug 201 is not displaced from its planted position during withdrawal of the elongate members 204.

The abutment member 207 may push the elongate members 204 from the withdrawal configuration in an open arrangement according to the pre-collection configuration when the sliding body 206 is completely moved upwards on the holding member 205. This is shown in the exemplary embodiment of Figure 3G.

In preferred embodiments, the transplantation head 203 may comprises a penetration depth controller 209 for setting a desired penetration depth of the elongated members 204 in the plot 101. Controlling the penetration depth of the plug can be important to ensure the correct planting depth of the seedling 200, which can affect seedling growth. Such means are for instance, but not limited to, a sensor for measuring the depth of penetration of the elongate members 204, or related elements, into the plot 101.

In the exemplary embodiment of Figures 3A-G, the penetration depth of the elongated members 204 into the plot of growth medium 101 comprises a stop 210A that limits the penetration of the elongate members 204. In the preferred embodiment, the stop 210A may interact by abutment with a grid 102 or a pipeline 103 for gas or liquid supply provided above the plot of growth medium 101 , to determine the position of the plot's surface in a simple manner. The penetration depth controller 209 thereby comprises a cylinder 210B filled with a gas, such as pressurized air, with a specific reference gas pressure. Stop 210A may preferably be a mechanical buffer. The stop 21 OA may be made from plastic, stainless steel, aluminum or any other type of metal or alloy. Preferably, the stop 21 OA is made from a light material, and is shaped to have a large surface that interacts with the grid 102 or pipeline 103, while limiting the overall volume of the stop 21 OA. In the exemplary embodiment of Figures 3A-3G, the stop 210 has the shape of a prism. The stop may also or alternatively comprise a sensor for determination the penetration depth, and electronic control of the penetration depth based on a preset depth. Sensors including ultrasonic sensors may be used in this respect.

In the exemplary embodiment of Figures 3A-3G, the stop 21 OA interacts with the grid 102 or a pipeline 103, for instance, by abutting the grid 102 or pipeline 103. The cylinder 210B comprises an internal piston (not shown). The stop 210A may be in fixed connection to holding member 206. During movement of the transplantation head 203 towards the plot 101 , the internal piston is pushed in the opposite direction in cylinder 210B, until the pressure inside the cylinder reaches a predetermined level at which point further downward motion of the transplantation head is stopped. The pressure is in the cylinder 210B is proportional to the depth of penetration. The stop 210A is calibrated such that a desired penetration depth into the plot 101 is achieved, by providing the cylinder 210B with a gas with a specific pressure, for instance 3 bar. Apparatus 100 may comprise a hose reel 1 1 1 that provides the reference gas for cylinder 210.

The elongate members 204 may further comprise interference members 21 1 . The interference members 21 1 may be made from plastic, stainless steel, aluminum or any other type of metal or alloy. Figure 3F shows the interference members 21 1 engaged with the stop 210A in the transfer configuration. In the exemplary embodiment of Figure 3F, each clamping member 21 1 and the elongate member 204 form an integral part. Each clamping member 21 1 and elongate member 204 can pivot about pivot point 212. In the transfer configuration, the interference members 21 1 engage to the stop 210A, and the interference members 21 1 and elongate members 204 pivot about pivot point 212. Consequently, the end tip of each elongated member 204 are pivoted to converge, and preferably touch or press against one another. In Figure 3G the elongate members 204 are in the pre-collection configuration. The interference members 21 1 and thus also elongate members 204 are held in place by guiding units 213. The end parts of the interference members 21 1 thereby touch or are pressed against one another. The guiding units 213 may be shaped as a cylinder, and may rotate along their longitudinal axis. In this way, when the sliding body 206 and elongate members 204 are moved upwards, the interference members 21 1 pass the guiding units 213 with limited friction, thereby limiting wear and damage of the interference members 21 1 .

In the withdrawal configuration, the elongate members 204 with interference members 21 1 are not held in position by the stop 210A (the interference members 21 1 and stop 210A are not in contact), and are not held in place by the guiding units 213, but have at least some free movement to pivot. The elongate members 204 are thus able to follow the plug-plot interface line 501 during withdrawal, with minimal force. In the exemplary embodiment of Figures 3A-G, the interference members 21 1 are arranged such that the interference members 21 1 and stop 210A substantially fit in one another in the withdrawal configuration.

Reference is made to Figure 4A, showing the front side of a seedling transplantation tool 300. The apparatus 100 may comprise one or more robot arms 109 (Figure 1 C) or gantries, each robot arm or gantry carrying a seedling transplantation tool 300 with multiple transplantation heads 203, or with a single transplantation head 203.

The illustrated transplantation tool 300 comprises multiple transplantation heads 203. The transplantation heads 203 in the exemplary embodiment of Figures 4A and 4B have elongate members 204 that are in the pre-collection configuration. Each transplantation head 203 may be arranged according to the embodiment of Figures 3A-G.

The transplantation heads 203 can be spaced from one another, and the spacing between the transplantation heads 203 is adjustable during use. The spacing can be adapted to the grid 102, and can be set via computer system 1 14. Accordingly, the transplantation heads 203 are relatively close to one another when collecting seedlings 200 from a seedling container, and then spread to a greater spacing when the seedlings are planted into the plot 101 . The extra spacing provides for continued seedling growth to a full crop.

Figure 4B shows the rear side of the same transplantation tool 300 as in Figure 4A. A cylinder 301 is visible, and can extend or retract horizontally to alter the spacing of the transplantation heads 203. This enables the spacing of the transplantation heads 203 to be adapted for collection and planting. This action may be achieved, for example, pneumatically or via, for example, a scissors mechanism.

Reference is made to Figures 5A and 5B. Figure 5A shows the transplantation tool 300 in the pre-collection configuration. Each transplantation head 203 is adjacent to a seedling 200 in a seedling container 303. The elongate members 204 are in an open arrangement, for insertion adjacent a plug of growth medium 201 enclosing the seedling root mass. The elongate members 204 are inserted into the seedling cavities 304 of the seedling container 303, along the plug seedling container interface line. The elongate members 204 of each transplantation head 203 are during or subsequently brought into the transfer configuration. In the transfer configuration, the elongate members 204 are in a downwardly convergent arrangement forming an apex, such that the plug 201 can be grasped. The elongate members may assume the arrangement according to Figure 3B, in which the distal tips of the elongate members 204 are pressed against one another in the transfer configuration to form wedge shape. The elongate members 204 in the transfer configuration are arranged such that the seedlings 200 can be transported from the seedling container to the plot of growth medium 101.

Transportation may be carried out by the robot arm 109 or a gantry, carrying the transplantation tool 300. The plugs 201 are thereby preferably supported by the elongate members, such that the plugs 201 are supported during transportation, e.g. such that the plugs 201 do not fall apart or fall out of the transplantation heads 203.

Once the transplantation tool 300 with transplantation heads 203 with seedlings 200 is above the plot 101 , the elongate members of each transplantation head 203 penetrate the ground by moving each transplantation head 203 towards the plot 101 , thereby pushing the plugs 201 completely or partially into the plot 101. The elongate members 204 of each transplantation head 203 are thereby still in the transfer configuration with an apex, such that the plot 101 can be easily penetrated, and an indent is created for receipt of the seedling plug 201.

Once the plugs 201 are at a desired height in the plot 101 , the elongate members 204 of each transplantation head 203 are brought into a withdrawal configuration, wherein the elongate members 204 of each transplantation head 203 withdraw from the plot of growth medium 101 along a plug-plot interface. The elongate members 204 are thereby preferably brought into a configuration in which the elongate members 204 can freely glide along the plug-plot interface, providing minimal force on the plug 201 , and not disturbing the surrounding plot 101. This may aid in limiting or avoiding airgaps at the plug-plot interface after removal of the elongate members 204 of each transplantation head 203 after withdrawal from the plot 101.

Figure 5B shows the transplantation tool 300, after the seedlings 200 have been planted in the plot 101. Figure 6 shows a flow diagram in which the above discussed method of transplanting a seedling 200 from a seedling container to a plot of growth medium is presented.

For comparison of embodiments of the present invention with the prior art manual transplantation, reference is made to Figures 7A-D. Figures 7A-D show transplantation of a seedling 200 according to a manual method. Accordingly, a tool 500 or hand or fingers are used to indent a cavity into plot 101 for receipt of a seedling, see Figure 7A. Subsequently, a seedling 200 with a plug of growth medium 201 is transplanted in the plot 101 . Usually, the plug of growth medium 201 does not exactly fit into the excavated cavity in the plot 101 , see Figure 5B, and it is therefore necessary to manually repack or squeeze the soil around the plug 201 after placement, see Figure 5C. Figure 5D shows the desired result, preferably leaving no air gaps between the plug-plot interface 501. However, the manual repacking is an additional step in the transplantation process, and may not be successful in removing air-gaps, may result in non-vertical orientation of the seedlings, and may affect the growth medium density around the seedling roots. Figures 8A-8C show the transplantation of a seedling 200 according to the present invention. Accordingly, a transplantation head 203 is used according to the exemplary embodiments of Figures 3A-G, or a transplantation tool 300 is used according to Figures 4A-B. Transplantation of the seedling 200 is carried out according to the method as shown in Figure 6. Accordingly, a transplantation head

203 is arranged near a container 303 of seedlings. The container 303 comprises cavities 304 for seedlings 200. The elongate members are then arranged adjacent to the seedling 200 with a plug of growth medium 201 , such that the elongate members

204 enclose the seedling root mass. This is shown in Figure 8A. The elongate members 204 are then brought into a transfer configuration, converging to an apex. This is shown in Figure 8B. Figures 8B and 8C shows elongate members 204 in the transfer configuration. In this configuration, the elongate members 204 are in a downwardly convergent arrangement forming an apex, such that the plug 201 is grasped or squeezed therebetween. In the exemplary embodiment of Figure 8B and 8C, the distal tips of the elongate members 204 are pressed against one another in the transfer configuration.

When in the transfer configuration, the elongate members 204 are arranged such that the seedling 200 can be transported from the seedling container to the plot of growth medium 101 , see Figure 8C. The plug 201 is thereby preferably supported by the elongate members, such that the plug 201 is supported during transportation, e.g. such that the plug 201 does not fall apart or falls out of the transplantation head 203. Once the transplantation head 203 with seedling 200 is above the plot 101 , the elongate members penetrate the ground by moving the transplantation head 203 towards the plot 101 , thereby pushing the plug 201 completely or partially into the plot 101 , see Figure 8D. The elongate members 204 are thereby still in the transfer configuration, with an apex such that the plot 101 can be easily penetrated. It is advantageous that the transplanting head generates the cavity for the seedling plug 201 during transplanting, since this aids in avoiding any need to preform cavities in the plot 101 , and to align subsequent planting actions with preformed cavities. Such an alignment on a large plot (e.g. a flower bed) is complex, not least because the surface of a flower bed is typically not perfectly planar, and in fact can be quite irregular. Once the plug 201 is at an appropriate depth of penetration for seedling growth, the elongate members 204 are brought into a withdrawal configuration, wherein the elongate members 204 are withdraw from the plot of growth medium 101 along a plug-plot interface surface 501 . This is shown in Figure 8E. The elongate members 204 are thereby brought into such a configuration, that the elongate members 204 can freely glide along the plug-plot interface 501 , with minimal force on the plug 201 , and not disturbing the surrounding ground, such that no or limited airgaps are provided between the plug-plot interface after removal of the elongate members 204 after withdrawal from the plot 101. It is noted that the additional step of steadying the soil around the plug 201 is preferred and not necessary, however, In preferred embodiments, the seedling plug 201 may be steadied or held in place during withdrawal of the elongate members 204 by the ram 208, providing a reaction force atop the plug 201 . Figure 8F shows the desired result, preferably leaving no air gaps between the plug-plot interface 501.

Reference is made to Figures 8G-I. Figures 8G-I show a transplantation head 203 in accordance with Figures 3A-G, in combination with a seedling 200 in a plug 201 of soil. Figure 8G shows the transplantation head with elongate members 204 in the pre-collection configuration, wherein the transplantation head is adjacent to the seedling 200 and plug 201. Figure 8B shows the same transplantation head 203, wherein the elongate members 204 have been plunged downwardly along the plug- container interface line, and now enclose the plug and seedling 200 root mass. The configuration of the elongate members 204 in Figure 8H may for instance correspond to the situation as illustrated in Figure 8A. Note that the elongate members 204 in Figure 8H remain substantially parallel to one another and that abutment member 207 is positioned such that ram 208 is above the plug 201. That is, the elongate members 204 have shifted downwardly with respect to abutment member 207 and ram 208, to accommodate the plug 201 within the volume between the elongate members 204. Upon withdrawal of the elongate members 204 during planting (as in figure 8F), the ram 208 blocks upward motion of the plug 201 , holding it in place in the plot 101 , to give a secure planting action.

Furthermore, Figure 8I shows transplantation head 203 with elongate members 204 in the transfer configuration. Accordingly, the elongate members are converged and form an apex. As can be seen in Figure 8I, plug 201 is grasped or squeezed between elongate members 204, and plug 201 has obtained a wedge shape. The configuration of the elongate members 204 may for instance correspond to the situation as illustrated in Figure 8B to 8F.

Reference is made to Figures 9A-D. Figures 9A and 9B show different perspectives of a seedling container supply system 700. Supply system 700 may be used in apparatus 100. Supply system 700 comprises a seedling container supply device 701 comprising a sliding body 702 comprising one pin or an array of pins 703. The sliding body can slide over rails from a supply side 709 to an operating side 710. The pins fit in one or more holders of a seedling container 704. Figure 9C shows an exemplary seedling container 704, and Figure 9D shows the bottom of the same seedling container 704. The container 704 comprises seedling cavities 705. Figure 9D shows that the seedling cavities 705 in the exemplary container comprises round bottom pin holes 707, wherein each pin hole 707 with four small extensions 708. The pins 703 of sliding body 702 can be inserted into one of these four extensions 708. In this way, the container 704 can be easily transferred from a supply side 709 at which a container 704 with seedlings can be supplied, to an operating side 710 at which the seedlings are being grasped for transplantation.

Supply system 700 may further comprise a locking device 71 1. The locking device 71 1 is used for locking a row of seedlings adjacent to a row of the seedling container 704 with seedlings that are being grasped. In the exemplary embodiment of Figures 7A-B, the locking device may comprise the same array of pins 703, although also a separate locking array of pins may be provided. Accordingly, the pins 703 lock the row of seedlings adjacent to a row of the seedling container 704 with seedlings that are being grasped, by inserting the pins 703 into the extensions 708 of this row in the seedling container 704, and by providing pressure on the edge of these extensions 708. In this way, the row of seedlings that is being locked by the locking device 703 cannot accidentally be pulled out of the container 704 when the adjacent row of seedlings is being grasped by transplantation heads 203. Supply system 700 may further comprise a seedling container retrieval device 712. This is shown in Figure 9A. The retrieval device 712 is used for transferring a seedling container 704 from an operating side 710 to a storage side 714. According to the exemplary embodiment of Figures 9A-B, the retrieval device 712 may comprise a pushing unit 712 that pushes the container to an intermediate side 713. Instead of a pushing unit 712, the retrieval device 712 may comprise a pin or an array of pins provided on a sliding body. The retrieval device 712 may comprise a further pin or a further array of pins, for dragging the container 704 from the intermediate side 713 to a storage side 714 in a similar fashion as described before, e.g. by coupling the pin or array of pins to the bottom extensions 708 of container 704. The storage side may comprise an elevator system. Accordingly, empty containers may be stacked at the storage side 714 by means of the elevator system 715.

Although the above example describes a supply device 701 is adapted to a specific container design 704, the skilled person understands that the supply device 701 may be adjusted to any container design. Furthermore, the above example describes a retrieval device 712 that transfers the container 704 from an operating side 710 to an intermediate side 713 to a storage side 714. The skilled person understands that an intermediate side may be omitted, and the intermediate side may in fact already serve as a storage side.

The present invention has been described with regard to specific embodiments; however, it will be clear to persons skilled in the art that a number of variants and modifications can be made without departing from the scope of the invention.

Claims

1. A transplantation head for transplanting a seedling from a seedling container to a plot of growth medium, the transplantation head comprising at least two elongate members, wherein the elongate members are arranged to assume at least the following configurations:

- a pre-collection configuration wherein the elongate members are in an open arrangement, for insertion adjacent a plug of growth medium about a seedling’s root mass;

- a transfer configuration wherein the elongate members are in a

downwardly convergent arrangement to grasp the plug of growth medium during transplantation, the downwardly convergent elongate members forming an apex for penetrating said plot of growth medium;

- a withdrawal configuration, wherein the elongate members are arranged to withdraw from said plot of growth medium along a plug-plot interface.

2. A transplantation head according to claim 1 , wherein the transplantation head further comprises an abutment-member that is arranged to push the elongate members apart in order to return the elongate members from the withdrawal configuration to the pre-collection configuration.

3. A transplantation head according to any preceding claim, further comprising a ram for abutting and retaining the plug of growth medium in the plot of growth medium during withdrawal of the elongate members.

4. A transplantation head according to any of the preceding claims, wherein the elongate members comprise a first plate and a second plate that are substantially parallel relative to one another in the pre-collection configuration, and wherein distal tips of each plate touch in the transfer configuration.

5. A transplantation head according to any of the preceding claims, wherein the transplantation head further comprises a penetration depth controller to limit the depth of penetration of the elongated members into the plot of growth medium, preferably wherein the depth of penetration is within 70% of the height z of the plug of growth medium, preferably 60% and more preferably 50%.

6. A transplantation head according to claim 5, wherein the penetration depth controller comprises a stop adapted to limit the penetration of the elongate members when the abutment-member contacts a grid or a pipeline upon said plot.

7. A transplantation head according to any preceding claim, wherein the

transplantation head further comprises a sliding system comprising a holding member and a sliding body, wherein the sliding body is in fixed connection to the elongated members and wherein the sliding body can slide over the holding member.

8. A transplantation head according to claim 7, wherein the stop is in fixed

connection to the holding member, and wherein the elongated members comprise interference members that mechanically engage the stop in the transfer configuration, such that distal tips of each elongated member touch.

9. A transplantation head according to any of the preceding claims, wherein the transplantation head is compatible for transplantation of Lisianthus seedlings.

10. A seedling transplantation tool comprising a plurality of transplantation heads, wherein one or more of the transplantation heads is in accordance with any of the preceding claims.

1 1. A seedling transplantation tool according to claim 10, wherein the

transplantation heads are spaced from one another, and wherein the spacing between the transplantation heads is adjustable.

12. A seedling transplantation apparatus comprising: a transplantation head

according to any of the claims 1-9 or a seedling transplantation tool according to any of claims 10 to 1 1 ; a robotic carrier, preferably a robot arm or gantry, for carrying the transplantation head.

13. An apparatus according to claim 12, wherein the apparatus further comprises a seedling container supply system comprising:

- a seedling container supply device to transfer the seedling container

containing seedlings to an operating side at which seedlings are being grasped for transplantation;

- a locking device to lock a row of the seedling container with seedlings adjacent to a row of the seedling container with seedlings that are being grasped;

- a seedling container retrieval device to transfer the seedling container to a storage side once the seedling container is empty.

14. An apparatus according to claim 12 or 13, wherein the apparatus further comprises a supply bridge for storage of further seedling containers.

15. An apparatus according to any of the claims 12-14, wherein the apparatus further comprises a computer system for at least inserting and adjusting operating settings of the robot arm and/or transplantation head.

16. An apparatus according to any of the claims 12-15, wherein the apparatus further comprises at least one walking bridge for operators to access the apparatus.

17. An apparatus according to any of the claims 12-16, wherein the apparatus further comprises a safety shield to protect operators to have direct interaction with the robot arm and transplantation head.

18. An apparatus according to any of the claims 12-17, wherein the apparatus further comprises a detection system arranged to detect the location of a grid that is provided above the plot of growth medium.

19. An apparatus according to any of the claims 12-18, wherein the apparatus is arranged to move over the plot of growth medium.

20. An apparatus according to claim 19, wherein the apparatus comprises wheels for moving over the plot of growth medium.

21.An apparatus according to claim 20, wherein the wheels are arranged to ride over pipelines that are provided over the plot of growth medium.

22. An apparatus according to any of the claims 19-21 , wherein the apparatus further comprises an alarm system for warning operators for movement of the apparatus.

23. An apparatus according to any of the claims 12-22, wherein the robot arm comprises at least one further transplantation head, wherein one or more of the further transplantation heads is in accordance with any of the claims 1-9.

24. An apparatus according to claim 23, wherein the transplantation heads are spaced from one another, wherein the spacing between the transplantation heads is adjustable.

25. An apparatus according to any of the preceding claims 12-24, wherein the apparatus comprises at least one further robotic carrier, carrying one or more transplantation heads according to any of the claims 1 -9, or one or more seedling transplantation tools according to any of claims 10 to 1 1 ;.

26. A method of transplanting a seedling from a seedling container to a plot of growth medium, the method comprising:

- bringing elongate members towards the seedling in the seedling container;

- inserting the elongate members adjacent a plug of growth medium

enclosing seedling root mass, while the elongate members are in an open arrangement;

- grasping the seedling with the elongate members, wherein the elongate members are provided in a downwardly convergent arrangement to grasp the plug of growth medium during transplantation;

- penetrating the plot of growth medium with the elongate members,

wherein the elongate members form an apex; - withdrawing the elongate members from the plot of growth medium, wherein the elongate members are arranged to withdraw along a plug-plot interface surface.

27. A method according to claim 26, using a transplantation head according to any of the claims 1 -9.

28. The method of any of claims 26 to 27 in which the elongate members are substantially as broad as a plug of growth medium in which the transplanted seedling is rooted.

29. The method of any of claims 26 to 28 in which the elongate members

converge to an apex having an internal angle of from 10° to 60°, preferably from 15° to 45°.

30. The method of any of claims 26 to 28 in which the elongate members during at least a part of transplantation are converged to an apex having an internal angle within 10° of a, wherein

wherein

x = a width of a seedling containing cavity in the seedling container z = a height of a seedling containing cavity in the seedling container

31.A seedling container supply system for use with an apparatus for

transplanting a seedling from a seedling container to a plot of growth medium, comprising:

- a seedling container supply device to transfer the seedling container

32. A seedling container supply system according to claim 28, wherein:

- the seedling container supply device comprises at least one pin that is arranged to drag the container to the operating position, wherein the pin is coupled to a bottom pinhole that is provided in the container;

- the locking device comprises at least one pin;

- the seedling container retrieval device comprises a pushing unit that pushes the container to an intermediate position, said seedling container retrieval device further comprising at least one further pushing unit that is arranged to push the container to the storage position.

33. A seedling container supply system according to claim 28 or 29, wherein the storage side comprises an elevator system for stacking empty containers.