WO2012121653A1

WO2012121653A1 - A method of handling plants in a transplanter, a transplanter and a transplanting unit

Info

Publication number: WO2012121653A1
Application number: PCT/SE2012/050253
Authority: WO
Inventors: Niklas BRANDMYR; Dick HILL; Lars JOSEPHSSON
Original assignee: Björkemar Construction & Consulting Bcc Ab
Priority date: 2011-03-10
Filing date: 2012-03-07
Publication date: 2012-09-13

Abstract

In a method for handling plants (P) in a transplanter for automated transplanting of plants, pots are stored and supported and individual plants grown in the pots are discharged therefrom in upper plant handling units, discharged plants are at intervals individually transferred through plant transfer units to lower transplanting units (5) each having a plant passage (6) passing plants to a transplanting position (TP) from which they are removed for transplanting through a reciprocating kicker mechanism (11) being movable relative to and thereby engaging a plant in the transplanting position Individual plants are temporarily blocked in the lower transplanting unit plant passage until a preceding plant has been removed from the transplanting position. A transplanter having at least one lower transplanting unit as well as a transplanting unit for such a transplanter are also provided.

Description

A method of handling plants in a transplanter, a transplanter and a transplanting unit.

TECHNICAL FIELD

The present invention generally concerns the automated, mechanized transplanting of plants or seedlings and specifically relates to methods and means for handling the plants/seedlings in association with the actual transplanting operation.

BACKGROUND

For several decades it has been known to improve the production of in particular, but not ex- clusively, vegetable crops by means of machines for transplanting e.g. seedlings and plants that have been grown in pots in greenhouses. The conventional transplanters generally comprise means for storing plant pots prior to transplanting, means for supporting the pots and for discharging therefrom the individual plants grown in the pots, means for transferring the discharged plants to a lower transplanting area of the transplanter and means for receiving the individual plants and for performing the actual transplanting thereof. The use of such transplanters that enable efficient automated, mechanized transplanting of mainly potted vegetable seedlings and plants has significantly reduced the production costs by providing a considerable reduction in planting time. However, existing transplanters have suffered from various shortcomings, such as less reliable separation and distributed feeding of the individual plants through the different means. All in all there is a demand for further developed transplanting machines, such as machines being adapted to computerized sequence control of the transplanting to achieve optimized results and machines having improved versatility both with regard to varying the number of simultaneously transplanted rows and to their mutual distance. A specific problem has been experienced in lower transplanting areas of the machines. In particular, synchronization of the plant transfer to the lower transplanting area and the actual transplanting thereof in the ground may be lost in case the transplanting sequence is disturbed for some reason. The result will in most cases be that some plants will not be properly transplanted and that other plants will be transplanted at irregular distances. Also, there is a continuous demand for even better productivity in terms of faster but yet trouble-free operation.

SUMMARY

A general object of the present invention is to provide a solution to the described problems and demands. A specific object is to suggest an improved method of enabling optimized individual handling of plants in association with the actual transplanting thereof. Another object of the invention to suggest an improved transplanter enabling optimized individual handling of plants in a transplanter in association with the actual transplanting thereof.

A further object of the invention is to suggest an improved transplanting unit enabling optimized individual transplanting of plants by a transplanter.

These and other objects are met by the invention as defined by the accompanying claims.

The invention generally relates to the handling of plants in a transplanter for automated transplanting of plants, where pots are stored and supported and individual plants grown in the pots are discharged therefrom in upper plant handling units. Discharged plants are at intervals individually transferred through one or several plant transfer units to at least one corresponding lower transplanting unit having a plant passage in which plants are passed to a transplanting position from which they are removed for transplanting through a reciprocating kicker mechanism being movable relative to and thereby engaging a plant in the transplanting position. Individual plants are temporarily blocked in the plant passage until a preceding plant has been removed from the transplanting position. The plant passage is positioned in a substantially vertical position for passing plants to the transplanting position and is pivoted reciprocally during a plant transplanting sequence for removing a plant from the transplanting position through pivoting the plant passage and the kicker mechanism being fixed to the plant passage. In a basic configuration a plant engaging and retaining plate forming a wall, especially a rear wall of the pivoting plant passage is maintained substantially stationary, thereby blocking the passing of a plant therethrough during at least part of the pivoting of the plant passage and the kicker mechanism from the substantially vertical position, for removing a plant from the transplanting position.

In accordance with another aspect of the invention is suggested an improved transplanter for the automated transplanting of plants and having upper plant handling units for storing and supporting pots and for discharging plants grown in the pots, respectively, at least one plant transfer unit for individually transferring discharged plants at intervals to at least one corresponding lower transplanting unit having a plant passage for passing plants to a transplanting position from which they are removable for transplanting through a reciprocating kicker mechanism. The kicker mechanism is movable relative to and into engagement with a plant in the transplanting position and a plant engaging and retaining plate selectively blocks the passing of a transferred plant through the plant passage and to the transplanting position until a preceding plant has been removed from the transplanting position. The plant passage is pivotally supported in a substantially vertical plant receiving position for passing plants to the transplanting position and is pivotal reciprocally from the plant receiving position during a plant transplanting sequence and the kicker mechanism is fixed to the plant passage for engaging and removing a plant from the transplanting position through the pivoting of the plant passage. In a basic configuration the plant engaging and retaining plate forms one wall of the plant passage and is fixed substantially stationary relative to a subframe of the lower transplanting unit, extending at least partially across an inside of the plant passage during pivoting thereof and thereby blocking the passing of a plant therethrough at least during pivoting of the plant passage and of the kicker mechanism from the substantially vertical position for removing a plant from the transplanting position.

In yet another aspect the invention relates to a transplanting unit for use in a transplanter wherein plants grown in pots are individually transferred at intervals to the transplanting unit. The transplanting unit has a plant passage for passing plants to a transplanting position from which they are removable for transplanting through a kicker mechanism being supported for reciprocal movement relative to and into engagement with a plant being in the transplanting position and a plant engaging and retaining plate selectively blocking the passing of a trans- ferred plant through the plant passage and to the transplanting position until a preceding plant has been removed from the transplanting position. The plant passage is pivotally supported in a substantially vertical plant receiving position for the passing of plants to the transplanting position and is pivotal reciprocally from said plant receiving position during a plant transplanting sequence. The kicker mechanism is fixed to the plant passage for engaging and removing a plant from the transplanting position through said pivoting of the plant passage. In a basic configuration the plant engaging and retaining plate forms one wall of the plant passage and is fixed substantially stationary to a frame of the lower transplanting unit, extending at least partially across an inside of the plant passage during pivoting thereof and thereby blocking the passing of a plant therethrough at least during pivoting of the plant passage and of the kicker mechanism from the substantially vertical position for removing a plant from the transplanting position. The basic inventive configurations present the advantages of: providing rapid and secure handling of plants for transplanting; and

providing excellent conditions for performing disturbance-free plant feeding through a lower transplanting unit; thereby

- optimizing operation and reliability of a lower transplanting unit; and thereby

improving productivity of a transplanter;

Preferred further developments of the basic inventive idea as well as embodiments thereof are specified in the dependent subclaims.

Advantages offered in addition to those described above, will be readily appreciated upon reading the below detailed description of embodiments of the invention.

BRIEF DESCRIPTION OF THE DRAWINGS

The invention and its further objects and advantages will be best understood by reference to the following description taken together with the accompanying drawings, in which:

Fig. 1A is a partly schematical top perspective view of an exemplifying embodiment of a transplanter according to the invention;

Fig. IB is a schematical side view of the transplanter of Fig. 1A;

Fig. 2A is a side view of a transplanting unit of the transplanter of Figs. 1A and IB; Fig. 2B is a view similar to that of Fig. 2 A, but with cover plates removed to show details of the transplanting unit; Fig. 3 is a partial end view of the transplanting unit illustrated in Figs. 2A and 2B, showing details of a plant passage and a kicker mechanism;

Figs. 4A-C are partly schematical illustrations of an embodiment of a transplanting sequence of a method according to the invention;

DETAILED DESCRIPTION

The invention will now be explained with reference to an exemplifying embodiment thereof. In particular, a transplanter of the invention as well as a lower transplanting unit being included therein will be explained with reference to an exemplifying embodiment that is illustrated in the accompanying drawing figures. The illustrations have the sole purpose of disclosing an exemplary embodiment of the invention and are not intended to limit the invention to the details thereof. The illustrated transplanter embodiment (Figs. 1 A and IB) relates to an application of the inventive solution to a general type of known transplanter that may be used for transplanting seedlings or plants (will throughout the remaining parts of the specification and claims be commonly referred to only as plants) in furrows formed in a field. However, it shall be noted that the inventive solution may be used for other specific applications requiring special additional features that are appropriate for such applications, such as transplanters having multiple sets of plant handling and/or transplanting units for simultaneous transplanting of plants in several parallel furrows. It shall thus be realized that the invention likewise covers the incorporation of such specific application related features and any appropriate combination of features disclosed and described herein.

Figs. 1A and IB illustrate an exemplary embodiment of a transplanter 1 to which the basic concept of the invention may be applied. This type of transplanter 1 is frequently used in applications for the automated transplanting of plants. It normally comprises a wheeled main frame 1 A having ground wheels 32 at a rear end, with regard to the transplanting direction D in a field and a connection 31 (indicated in Fig. IB) for the hitch points of a standard tractor hitch at a forward end. Notwithstanding this, the transplanter 1 could in alternative configur- ations also be a self propelled vehicle. Parts of the transplanter 1 are also covered by plates that are exemplified by plates 33. On the transplanter frame 1A are mounted several basic plant handling units of the transplanter 1. Said units may include a storage rack 2 for storing plant pots PB to be processed, an upper pot support and plant discharge unit 3 and at least one plant transfer and distribution unit 4 for communicating individual plants P in associated transfer tubes (not specifically shown) between the pot support and plant discharge unit 3 and at least one lower transplanting unit 5 directing plants P to a transplanting position TP (Figs. 2B and 4A-C). For simplicity the upper pot support and plant discharge unit 3 and the plant transfer and distribution unit 4 will for the rest of the description and claims be referred to as a plant discharge unit 3 and plant transfer unit 4, respectively. The transplanter main frame 1A may also support an empty plant pot rack 30. In the basic operation of the exemplary transplanter configuration, multiple plant pots PB are stored at several levels in the storage rack 2. The pots PB may be of a conventional type having plants P accommodated in multiple rows of plant compartments therein (not shown) and are normally removed individually from the rack and introduced in the plant discharge unit 3.

In the plant discharge unit 3 plants are discharged from the pots PB. Plants are normally pushed out from their pot PB and are then dropped in the plant transfer unit 4 that individually transfers discharged plants at intervals to corresponding lower transplanting units 5 each having a plant passage 6 for passing plants P to a transplanting position TP. The transplanting units 5 control feeding of the plants P through their plant passage 6 (Fig. 2B), also named a plant drop tube, and to the transplanting position TP for spaced transplanting into the ground along a transplanting furrow (not specifically shown) formed by a plow assembly 22. As described so far the transplanter 1 is configured and operated mainly in conventional manner and for that reason as well as for reasons of clarity the plant discharge unit 3 and the plant transfer unit 4 have not been illustrated or described in detail. The generally described plant discharge unit 3 as well as plant transfer unit 4 may be of any appropriate design serving the purposes of the invention.

As was briefly discussed initially, prior art designs of this general type of transplanter may cause plants to be passed through the lower transplanting unit before the preceding plant sequence has been completed, with the result that they will simply be dropped on the ground without being properly transplanted in the ground. This is especially so in situations where the transplanting is disturbed for some reason, causing plants to enter the transplanting unit too soon so that they never reach the transplanting position TP. The same problem may also result from an effort to increase productivity by speeding up plant transfer through the upper discharge and transfer units of the transplanter. The invention intends to solve problems of the type that were discussed above as well as in the introduction. To overcome such shortcomings and problems associated with common transplanters, a new concept is proposed for avoiding non-transplanted plants and for allowing an increase of the transplanting rate with maintained distances between the transplanted plants. A basic feature of the solution is the provision of means for temporary retaining a plant in the plant passage of the transplanting unit until a preceding plant has been removed from the transplanting position.

In Figs. 2A-B, 3 and 4A-C (sections along line A-A of Fig. 3) is illustrated an exemplary practical embodiment of a transplanting unit 5 of a transplanter 1 as generally described above. The basic inventive concept has been applied to this transplanting unit 5, the exterior of which is illustrated in Fig. 2A and is essentially conventional. The transplanting unit 5 includes a subframe 5 A, a coupling assembly 5B for connection to the transplanter main frame 1A and cover plates 5C shielding operational parts thereof. As is conventional the transplanting unit 5 also includes a pair of compactor wheels 21 for closing a furrow formed in the ground G (Fig. 4C) by a plow 22. A ground engaging skid 23 is also provided and serves to maintain the transplanting unit 5 in an appropriate position promoting effective operation of the plow 22 and of the compactor wheels 21. In Fig. 3B the transplanting unit 5 is shown with the skid 23 and the cover plates 5C on one side removed. This reveals a plant passage 6 having a generally tubular shape, through which plants P being individually supplied from the plant transfer unit 4 are at intervals passed on to a transplanting position TP. In the transplanting position TP plants PI are received in a space that is formed between side portions 22A, 22B of the plow (Fig. 3) and that in cross section has a generally V-shaped design. As seen in the planting direction D this transplanting position TP is located immediately in front of the compactor wheels 21.

For the actual transplanting the plants PI are removed from the transplanting position TP by the operation of a reciprocating kicker mechanism 11 that is fixed to the plant passage 6 and that may form a front wall 8 of the plant passage 6 or an extension thereof. The kicker mechanism 1 1 is movable relative to and into engagement with a plant PI received in the transplanting position so that operation thereof will push the plant PI out from the trans- planting position TP in the plow 22. The plant PI pushed out by the pivoting of the kicker mechanism 11 will drop into the formed furrow (not shown) that is then immediately closed by the compactor wheels 21. This kicker mechanism 1 1 operation is performed by reciprocally pivoting the entire plant passage 6 that with side walls 9 and 10 thereof is supported for pivoting around a pivot generally designated by the reference number 16. Pivoting of the plant passage 6/kicker mechanism 11 is performed by a drive assembly. The drive assembly has conventionally been a mechanical drive using drive chains and sprockets. In the preferred embodiment of the invention such drive assemblies have been replaced by a double acting fluid cylinder 15. By controlling the fluid cylinder 15 through a transplanter control unit CU as well as by eliminating inaccuracies caused by mechanical play in the conventional drive assemblies much more rapid and yet uniform and secure transplanting may be achieved with maintained regular mutual distances between the transplanted plants P. This drive concept is likewise unique for the invention. The detailed configuration and operation of the transplanting unit 5 shall now be described with specific reference to Figs. 4A-4C and to some extent also to Figs. 2B and 3. Plants P that are discharged from a transplanter 1 plant transfer unit 4 are individually dropped into a very schematically illustrated discharge tube 24. This discharge tube 24 is attached to and communicates individual plants P at regular intervals to the plant passage 6 of the trans- planting unit 5. The pivotally supported plant passage 6 is shown in Fig. 4 A in an essentially vertical plant receiving position VP. During a first step I (Fig. 4A) of a plant transplanting sequence I-III the plant passage 6 is in the vertical plant receiving position VP wherein it receives individual plants PI for passing them to the transplanting position TP. During step II (Fig. 4B) of the transplanting sequence I-III a plant PI in the transplanting position TP is removed therefrom by the reciprocal pivoting of the plant passage/kicker mechanism 6/11 from said vertical plant receiving position VP. During said step II of the transplanting sequence I-III a subsequently discharged plant P2 is dropped into the discharge tube 24 and supplied to the plant passage 6 being pivoted from the vertical position. According to the invention the plant passage 6 and/or the kicker mechanism 11 during this sequence step II cooperate with a plant engaging and retaining plate 7. The plant engaging and retaining plate 7 practically forms a rear wall of the plant passage 6, being positioned opposite the front wall 8. The plant engaging and retaining plate 7 and the kicker mechanism 2012/050253

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11, or an extension thereof, thus form opposing walls of the plant passage 6. They cooperate in selectively blocking the passing of subsequently discharged and transferred plants P2 therethrough and to the transplanting position TP during sequence step II, when the kicker mechanism/plant passage is in a pivoted position PP. This blocking of a subsequent plant P2 in a retained position RP (Fig. 4B) continues until the preceding plant PI has been removed from the transplanting position TP and the plant passage/kicker mechanism 6/11 returns towards the vertical position VP.

This selective plant blocking is accomplished by supporting the plant engaging and retaining plate 7 independently of the plant passage 6 and the kicker mechanism 11. In the illustrated embodiment the plant engaging and retaining plate 7 is fixed, by attachments 17, 18, with respect to the transplanter unit 5 sub frame 5A so that it will remain stationary as the plant passage 6 and the kicker mechanism 11 pivot. As a consequence of its fixed support the plant engaging and retaining plate 7 will become extended at least partially across an inside of the plant passage 6 during pivoting thereof, to thereby block the passing of a plant P2 therethrough at least during pivoting of the plant passage 6 and of the kicker mechanism 1 1 from the substantially vertical position VP for removing a plant from the transplanting position TP.

In the illustrated embodiment the plant engaging and retaining plate 7 has such a length that it will engage the pivoting plant passage 6 rear wall 8 or kicker mechanism 1 1 during the pivoting movement. The plate 7 in this case consists of a relatively thin plate or sheet of plastic or metal material so that it will be appropriately resilient to yieldingly engage the rear wall 8 or kicker mechanism 11 during the complete pivoting movement and securely close the plant passage.

When the kicker mechanism 11 has completed its plant removal function the plant passage 6 and the kicker mechanism 11 return, during the transplanting sequence step III, to the vertical plant receiving position VP to release the subsequent plant 2 so that it may be passed on to the transplanting position TP (Fig. 4C).

In the above described transplanter and transplanting unit the handling of plants P in association with the automated transplanting thereof is performed by transferring plants through plant transfer units 4 and to corresponding lower transplanting units 5 each having a plant passage 6. Plants are passed in the plant passages 6 to a transplanting position TP from which they are removed for transplanting by the reciprocating kicker mechanism 11 that, as was described above, is moved relative to and thereby engages a plant in the transplanting position. According to the invention the desired, improved plant handling control is obtained by temporarily blocking individual successive plants P2 in the lower transplanting unit 5 plant passage 6 until a preceding plant PI has been removed from the transplanting position TP.

Specifically, the lower transplanting unit 5 plant passage 6 is maintained in a substantially vertical position VP for the passing of plants to the transplanting position TP and is pivoted reciprocally during a plant transplanting sequence I-III for removing a plant PI from the transplanting position TP through pivoting of the plant passage 6 and the kicker mechanism 1 1 being fixed thereto. In a development of the inventive plant handling a plant engaging and retaining plate 7 forming a wall, especially a rear wall of the pivoting plant passage 6, is maintained at least substantially stationary during the pivoting of the plant passage 6. Thereby, the retaining plate 7 blocks the passing of a plant P2 therethrough at least during part of the pivoting of the plant passage 6 and of the kicker mechanism 11 from the substantially vertical position VP for removing a plant from the transplanting position TP.

Preferably, in the described handling of the plants the reciprocating pivoting of the plant passage 6 and its kicker mechanism 1 1 is performed by means of a double acting fluid actuator 15. Accordingly, one further aspect of the invention concerns the above mentioned unique drive assembly 15 used in the described embodiment of the transplanter 1. In accordance with the invention a lower transplanting unit 5 to which individual plants are transferred at intervals and that has a pivotally supported plant passage 6 for passing plants P to a transplanting position TP from which they are removable for transplanting through a reciprocating kicker mechanism 1 1 that is fixed to the passage 6 and that is movable relative to and into engagement with a plant in the transplanting position, is characterized by a fluid actuator, preferably a double acting fluid cylinder 15 that is pivotally supported by the sub frame 5A of the lower transplanting unit 5 and is pivotally connected to the plant passage 6 for reciprocally pivoting the plant passage and the kicker mechanism. In a further development of this aspect the transplanting unit is characterized in that the fluid cylinder 15 is connected to and controlled by a control unit CU of a transplanter 1. P T/SE2012/050253

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In alternative, but not specifically illustrated embodiments of the invention variations of the different illustrated parts may be employed without departing from the scope of the invention. One example thereof is the use of various kicker and plant passage configurations with the kicker being integral with the plant passage or being a separate part that is fixed to the plant passage front wall. In other advantageous alternative solutions the entire plant passage may be pivotally supported in various other ways than by the very schematically illustrated pivot 16.

In a further variation the plant engaging and retaining plate may not be completely stationary or fixed in position, but may be resiliently pivotal as long as its pivoting is basically independent from the pivoting of the plant passage and kicker mechanism and is only indirectly coupled thereto by the engagement between the plate and the plant passage/kicker mechanism. In such an alternative embodiment the plate may be solid and not flexible but may instead be separately pivotal from a generally vertical position, against a sufficiently strong biasing force that will provide the secure plant blocking engagement with the kicker mechanism. Thus the plant retaining plate may be attached in any appropriate alternative way providing the desired function and may be formed of any suitable material, including plastic or metal material, having the appropriate resiliency/biasing to provide secure temporary retaining of the plants and yet allow full pivoting of the kicker mechanism. It should be obvious that the invention covers any such variations that fall within the general knowledge of the skilled practitioner.

The invention has been described in connection with what is presently considered the most practical and preferred embodiments but it shall be understood that the invention is not limited to the disclosed embodiments. It likewise covers any feasible combination of features described and illustrated herein and is therefore intended to cover various modifications and equivalent arrangements included within the spirit and scope of the appended claims.

Claims

PATENT CLAIMS

1. A method of handling plants (P, PI, P2) in a transplanter (1) for automated transplanting of plants, wherein:

- pots (PB) are stored and supported and individual plants grown in the pots are discharged therefrom in upper plant handling units (2, 3);

- discharged plants are at intervals individually transferred through one or several plant transfer units (4) to at least one corresponding lower transplanting units (5) having a plant passage (6) in which plants are passed to a transplanting position (TP) from which they are removed for transplanting through a reciprocating kicker mechanism (11) being movable relative to and thereby engaging a plant (PI) in the transplanting position;

- temporarily blocking individual plants (P2) in the plant passage until a preceding plant (PI) has been removed from the transplanting position; and

- positioning the plant passage (6) in a substantially vertical position (VP) for passing plants (P, PI, P2) to the transplanting position (TP) and pivoting it reciprocally during a plant transplanting sequence (Ι-ΠΙ) for removing a plant (PI) from the transplanting position through pivoting the plant passage and the kicker mechanism (11) being fixed to the plant passage, characterized by:

- maintaining substantially stationary a plant engaging and retaining plate (7) forming a wall, especially a rear wall of the pivoting plant passage, thereby blocking the passing of a plant (P2) therethrough during at least part of the pivoting of the plant passage and the kicker mechanism from the substantially vertical position (VP) for removing a plant (PI) from the transplanting position.

2. A method according to claims 1, characterized by performing the reciprocating pivoting of the plant passage (6) and its kicker mechanism (11) by means of a double acting fluid actuator (15).

3. A transplanter (1) for the automated transplanting of plants (P, PI , P2) and having-:

- upper plant handling units (2, 3) for storing and supporting pots (PB) and for discharging plants grown in the pots, respectively; - at least one plant transfer unit (4) for individually transferring discharged plants at intervals to;

- at least one corresponding lower transplanting units (5) having a plant passage (6) for passing plants to a transplanting position (TP) from which they are removable for transplanting through a reciprocating kicker mechanism (11) that is movable relative to and into engagement with a plant (PI) in the transplanting position:

- and a plant engaging and retaining plate (7) selectively blocking the passing of a transferred plant (P2) through the plant passage and to the transplanting position until a preceding plant (PI) has been removed from the transplanting position-;

- wherein the plant passage (6) is pivotally supported in a substantially vertical plant receiving position (VP) for the passing of plants (P, PI, P2) to the transplanting position (TP) and is pivotal reciprocally from said plant receiving position during a plant transplanting sequence (I-III); and

- wherein the kicker mechanism (11) is fixed to the plant passage for engaging and re- moving a plant from the transplanting position through said pivoting of the plant passage, characterized in that:

- the plant engaging and retaining plate (7) forms one wall of the plant passage and is fixed substantially stationary relative to a subframe (5 A) of the lower transplanting unit, extending at least partially across an inside of the plant passage during pivoting thereof and thereby blocking the passing of a plant (P2) therethrough at least during pivoting of the plant passage and of the kicker mechanism from the substantially vertical position for removing a plant (PI) from the transplanting position.

4. A transplanter (1) according to claim 3, characterized by a fluid actuator (15) that is pivotally supported by the subframe (5 A) of the lower transplanting unit (5) and is pivotally connected to the plant passage (6) for reciprocally pivoting it.

5. A transplanter according to claims 3 or 4, characterized in that the plant engaging and retaining plate (7) and the kicker mechanism (11) or an extension (8) thereof form opposing walls of the plant passage (6) and cooperate in blocking the passing of a plant (P) therethrough.

6. A transplanting unit (5) for use in a transplanter (1) in which plants (P, PI, P2) grown in pots (PB) are individually transferred at intervals to the transplanting unit having-:

- a plant passage (6) for passing plants to a transplanting position (TP) from which they are removable for transplanting through a kicker mechanism (11) that is supported for reciprocal movement relative to and into engagement with a plant (PI) being in the transplanting position:

- a plant engaging and retaining plate (7) selectively blocking the passing of a transferred plant (P2) through the plant passage and to the transplanting position until a preceding plant (PI) has been removed from the transplanting positionT

- wherein the plant passage (6) is pivotally supported in a substantially vertical plant receiving position (VP) for the passing of plants (P) to the transplanting position and is pivotal reciprocally from said plant receiving position during a plant transplanting sequence (I-III); and

- wherein the kicker mechanism (11) is fixed to the plant passage for engaging and removing a plant (PI) from the transplanting position (TP) through said pivoting of the plant passage, characterized in that:

- the plant engaging and retaining plate (7) forms one wall of the plant passage and is fixed substantially stationary to a frame (5 A) of the lower transplanting unit, extending at least partially across an inside of the plant passage during pivoting thereof and thereby blocking the passing of a plant (P2) therethrough at least during pivoting of the plant passage and of the kicker mechanism from the substantially vertical position for removing a plant (PI) from the transplanting position.

7. A transplanting unit (4) according to claim 6, characterized by a fluid actuator (15) that is pivotally supported by the subframe (5A) of the lower transplanting unit (5) and is pivotally connected to the plant passage (6) for reciprocally pivoting it.

8. A transplanting unit (4) according to claims 6 or 7, characterized in that the plant engaging and retaining plate (7) and the kicker mechanism (11) or an extension (8) thereof form opposing walls of the plant passage (6) and cooperate in blocking the passing of a plant (P2) therethrough.