WO2025132689A1

WO2025132689A1 - System and method for grafting plant stems

Info

Publication number: WO2025132689A1
Application number: PCT/EP2024/087261
Authority: WO
Inventors: Wim Van Der Meijden; Wim Struijk; Mario VAN DE WERKEN; Henk-Jan VAN OOIJEN
Original assignee: IG Specials BV
Current assignee: IG Specials BV
Priority date: 2023-12-18
Filing date: 2024-12-18
Publication date: 2025-06-26
Anticipated expiration: 2026-06-18
Also published as: WO2025132656A9; WO2025132689A9; WO2025132675A9; WO2025132656A1; WO2025132675A1

Abstract

The present invention discloses blade tool for grafting, a system for preparing stems for grafting, a method for preparing for grafting and a grafting method. A blade tool for simultaneously cutting a pair of plant stems is provided. The blade tool comprises a blade tool frame and blade subframe coupled to the blade tool frame and a blades drive arranged to move the blade subframe with respect to the blade tool frame. The one or more blades mounted on the blade subframe with a proximal end, the one or more blades having a blade edge that extends to a distal end. Further, one or more second blades are mounted on the blade subframe with a second proximal end, the one or more second blades having a second blade edge that extends to a second distal end. The blade edges are facing each other. This allows cutting one stem between the facing blade edges. An anti-blade tool is provided having slits that receive the blade and blade edges while cutting. The system has grippers that hold the stem and the cutting action takes place between the two grippers.

Description

SYSTEM AND METHOD FOR GRAFTING PLANT STEMS

TECHNICAL FIELD

[0001] The disclosed technology relates generally to systems, tools and methods for grafting and for preparation for grafting. The disclosed technology relates to blade and transfer tools and method used in the preparation for grafting.

BACKGROUND

[0002] Grafting is a horticultural technique that involves joining the tissues of one plant, called the scion or budwood, with the tissues of another plant, called the rootstock or understock. The primary purpose of grafting is to propagate and cultivate “new” plants with desirable characteristics.

[0003] One objective during grafting is to create clean contact areas on the stem of the scion-side and the stem of the rootstock-side. To achieve this, the stems are often cut, using a blade, at an angle to increase the surface areas of the contact areas. The contact area of the scion is then aligned on top op of the contact area of the rootstock, and both stems are clamped together using a graft element such that the contact areas stay connected. Over time, the scion and rootstock tissues grow together, forming a single plant. This process is aided by the flow of nutrients and water through the newly connected tissues.

[0004] Due to the precise, delicate, and spatially complex nature of this work, grafting is often performed manually by skilled workers. Unfortunately, this results in several disadvantages such as a lack of reproducibility, controllability, and sterility throughout the process. Further, the risk of grafts failing over time as a result of diseases makes manual manipulation of plant stem sections less than optimal. Ideally, the preparation of stems should happen in a sterile environment.

[0005] Automating the grafting process can result in great advantages in terms of speed, reproducibility, quality assurance, and sterility. Further, it should be noted that automating grafting allows for more insights into production errors, troubleshooting, and controllability of specific grafting parameters that may need to be tuned when grafting specific species of plants. [0006] With grafting, the bottom-part (rootstock) of one plant is joined to the top-part (scion) of another plant by means of a graft element, such as a clip. If one were to automate such a procedure, several factors would need to be taken into account: (i) robust identification and localization of plant material, (ii) careful handling of plant material, (iii) precise cutting of plant material, (iv) precise alignment of contact surfaces, (v) minimization of (air)gaps between contact surfaces, (vi) safe and precise securing of a graft element, (vii) maintaining precise environmental conditions, (viii) compatibility with a wider range of plants, and/or (ix) maintaining sterility throughout the system. Grafting is a complex process and there are several reasons why a graft may fail: physical damage to the plant material or tissues, overstressing the stems (mechanically), infections, misalignment, too much distance between the contact surfaces, dehydration, air embolisms between the contact surfaces, etc. The percentage of grafted plants that fail per batch can be high. This reduces revenue. Available systems, including systems which incorporate computer vision systems for parts of the preparation process, are expensive and complex.

[0007] Plants come in a variety of shapes and sizes and are generally difficult to manipulate for machines and robots. Nonetheless, there is a large interest in overcoming obstacles in plant manipulation, as it may benefit automation efforts in greenhouses. One common example of such an obstacle relates to the engagement of plant material, such as stems, because robots are unable to estimate the required amount of force to apply to the plant to grasp and lift it. Too little force results in the plant falling from its grasp, too much force squishes the plant and causes damage. This is all further complicated by the fact that plants are never identical, meaning that each of them requires a different type of grasp or force to lift.

[0008] In grafting systems, highly complex processes are performed on delicate plant material at high speeds. W02012101134A1 relates to a graft element and a system and method for joining plant stem sections using such graft element. It presents some tools for automating steps in the grafting process. However, due to the complex nature of grafting, it would be desirable to have a single system that automates every step in the grafting process. US2017/0325409 discloses holding two stems of plants to be grafted. Each stem is engaged by two grippers. Two separate V-shaped blades are driven separately to cut each of the respective stems by penetrating a V-shaped recess of a gripper. WO2016/092552 discloses cutting the single stem of a rooted plant with leaves between two grippers that hold that single stem.

[0009] Plant material typically has irregular geometries that requires machines to first detect and identify the specific part of the plant suitable for cutting. Processing speed and cutting accuracy are at a trade-off here. It is highly desirable that an automated solution to these obstacles is capable of quickly localizing a plant stem section, is robust, fast, and still capable of executing precise cuts to optimize the chance of a graft being successful.

[0010] The present invention addresses at least one of the shortcomings in preparing plants stem sections, in particular in relation to grafting machines, by providing tools, systems and methods for preparing and cutting plant material, in particular stems of plants.

SUMMARY

[0011] To address at least one the above discussed drawbacks of the prior art, there is proposed, according to a further aspect a blade tool for simultaneously cutting a pair of plant stems. The simultaneous cut pair of plant stems is preferably formed by a scion and rootstock. By cutting the rootstock and scion generally simultaneously, the cutting action can be performed in a generally single action, which reduces differences between the cut of the scion and the (simultaneous) cut of the rootstock. This reduces differences in the cut and increases the chances of a successful subsequent graft.

[0012] In embodiments, the blade tool comprises a blade tool frame and a blade subframe. The blade subframe is coupled to the blade tool frame. The coupling comprises a blades drive that is arranged to move the blade subframe with respect to the blade tool frame. The blades drive allows moving the blade subframe with respect to the blade tool frame. The blades drive can be operated to performing the cutting operation. The blade subframe, carrying the blades and blades edges, can be moved to perform the cutting operation.

[0013] In embodiments, one or more blades are mounted on the blade subframe. A proximal end of the blade is connected to the blade subframe. The distal end of the one or more blades points away from the blade subframe. The blade edge of the blade extends from the distal end. The distal end can be moved in the direction of a stem-to-be-cut and the blade edge near the distal end will start the cut. The blade is arranged to cut one stem of the pair of stems.

[0014] For generally simultaneously cutting a pair of stems, one or more second blades are mounted on the blade subframe. The second blade cuts the other stem of the pair of stems. The second proximal end of the second blade is connected to the blade subframe. The second blade will have a second blade edge that extends to a second distal end. The second stem-to- be-cut will be cut by the second blade edge at the distal end. The one or more blades and one or more second blades mounted to the blade subframe are arranged to simultaneously cut a pair of stems to be cut by driving the blade subframe with respect to the blade tool frame with a blades drive.

[0015] According to embodiments of the invention the blade edges face each other. Upon cutting, the first blade will feel resistance in a direction opposite to the blade edge, whereas the second blade will feel resistance in the direction opposite the second blade edge. As the blade edges face each other, the forces felt are in opposite direction, resulting in lowering, preferably cancellation, of the reaction forces during cutting. By such that a stem can be positioned between the blade edges to be cut from opposite sides. The blade edges face each other such that a stem can be positioned between the blade edges to be cut from opposite sides.

[0016] In embodiments, a pair of one or more blades and one or more second blades has blades that are oriented in parallel planes. The blades are preferably flat. The blades are preferably shaped like a razor blade, with a blade edge. The flat blade and flat second blade are positioned to lay in parallel planes. The distance between the parallel planes allows positioning the blades at a distance so that different stems, e.g. a scion and a rootstock, can be cut by the two blades of the pair.

[0017] In embodiments, the blade edges of the two blades of the pair of the blades have blade edges that extend in the parallel planes. This results in cuts that extend in parallel planes.

[0018] In embodiments, the pair of the blade and the second blade have blade edges that are positioned to, in the parallel planes, converge towards each other from the distal end. While the blade edges face each other, towards the proximal direction they converge. Preferably the blade edges are positioned mirror symmetrical with respect to a middle plane, preferably the plane in which the stems to be cut extend. This results in similar cutting characteristics of the blade pair on the stems. Also, by a mirror symmetrical position, the reaction forces are similar in size and thus similarly reduced or cancelled.

[0019] In embodiments, the distance between the blade edges of the blade and second blade increases towards the distal end. When the cutting action comprises cutting the stem by moving the blade tool in the distal direction, the distal part of the blade edge will cut the stem first.

[0020] Preferably the blade converges towards the blade distal end. The flat blade can have a point or triangle shape, the distal end being a point.

[0021] In embodiments, the pair of the blade and second blade are mounted on a blades pair mounting body that is mounted to the blade subframe. The blade pair mounting body allows to mount multiple pairs of blade and second blade on the blade subframe. Preferably a row of blades pair mounting bodies can be mounted to the blade subframe.

[0022] Preferably the blades pair mounting body comprises two mounting surfaces. Flat blades can be positioned on the surface and are supported by the flat mounting surface. The two mounting surfaces preferably extend in parallel planes so as to position the blades in parallel planes.

[0023] In embodiments, a first row of multiple blades and a second row of multiple second blades is mounted on the blade subframe. Preferably pairs of blades are mounted in adjacent positions. Preferably blades pair mounting blocks are positioned in a row onto the blade subframe, the multiple blades pair mounting bodies each arranged in similar orientations.

[0024] In an embodiment, the blade tool frame is coupled to the blade subframe via a track, preferably a linear track. This allows guided moving of the two frames, preferably according to a predetermined movement. Preferably the blades drive is arranged to move the blade subframe in a direction towards the distal end of the blade. The blades drive can thus move the distal end towards stems to be cut.

[0025] In embodiments, the track extends in a first direction and the blade edge extends along the first direction. By moving the blade subframes with blades in the first direction, the blade edge can doing its cutting action, by being progressively inserted into the stem to be cut.

[0026] Preferably the blade tool frame is mountable in a frame of a grafting system. By mounting the blade tool in a grafting system, a cutting operation can be performed in the grafting system. The blade tool frame is mounted with mounting device that extend in second direction, perpendicular to the drive direction of the blades drive. The blades drive is for performing the cutting action. The blade tool can be moved to and away from the processing locations for stems by moving the blade tool in a second perpendicular direction. The grafting system can have a guide or the blade tool frame has a guide for guidance in the second direction.

[0027] The blade tool frame is coupled via a blade tool drive, such as a robot arm, to the frame of grafting system.

[0028] Further drawbacks of the prior art are reduced, according to a further aspect, by proposing a system for preparing plant stem sections for grafting. The grafting system is arranged to allow cutting of the stems-to-be-grafted, such as scions and rootstocks, by holding those stems-to-be-grafted in a position ready for cutting. The cut rootstock and scions are subsequently grafted. In grafting system proposed, engaging and positioning the stems-t- be-grafted is improved.

[0029] In embodiments, the grafting system comprises a first gripper for holding a stem of a plant to be grafted. Holding the stem can comprise engaging, enclosing, constraining and/or gripping. The grafting system can have a second gripper also arranged for holding that stem of the plant. The second gripper is arranged to hold the stem at a distance from the first gripper. The first and second gripper consequently hold one stem at two distance locations. [0030] In embodiments, a blade is mounted on a blade subframe of the grafting system. The blade subframe can move in the grafting system. A blade motor couples the blade subframe for moving the blade. The blade motor is arranged to move the blade between the first and second grippers. The stem extends between the two grippers and the blade will cut the stem when the blade subframe with blade is moved between those first and second grippers.

[0031] To further support the gripped stem while cutting, and using the grafting system that has two grippers for holding a single stem, a stem support is provided between the first and second grippers. The stem support can provide support in a counter direction to the cutting movement of the blade. This prevents, at least partially, moving of the stem during cutting. Preventing movement of the stem during cutting by the stem support allows for a more precise cut, which increases the chances of a successful graft, as well as decreasing the chances of damaging the plant stem during cutting due e.g. to deformation, bending, and/or buckling of the plant stem.

[0032] Preferably the stem support has an elongated back support surface for supporting an elongated part of the stem of the plant, wherein the elongated support surface extends over a part of the length between the first and the second gripper. This back support of the stem increases the consistency of the cut by the blades. [0033] More preferably in embodiments, the stem support comprises a slit for receiving the blade for cutting the stem of the plant, wherein the slit extends across the elongated support surface. By providing a slit, the blade can enter into the space created by the slit, while the parts surrounding the slit continue to provide (back) support for the stem while being cut. [0034] In embodiments, the system comprises a first gripper drive, a second gripper drive. The first and second gripper drive can open and close the gripping elements of the first and second gripper respectively. In closed position, the gripper can enclose the surrounded stem. The gripper can comprise two or more elements for enclosing, grasping and/or constraining the stem.

[0035] In embodiments, the system is arranged to drive the first gripper drive to hold the stem with the first gripper and to then drive the second gripper drive to hold the stem with the second gripper. This allow first enclosing or gripping at a first location with a first gripper, which is arranged to locate the stem while the stem only has a roughly defined location. A second gripper can be driven subsequently to also enclose and grip the stem. The second gripper can be less complex as the stem has already been located and the position is more defined. After the two-stepped gripping, the blade motor is driven and the stem is cut with the blade.

[0036] In embodiments, the system comprises a stem support drive. The stem support drive will be operated by the system to move the stem support between the two grippers, after driving the second gripper and before cutting.

[0037] Preferably the system also comprises a further gripper drive to move the first and second gripper away, and preferably towards, each other. This allows increasing the distance, e.g. after the second gripper has enclosed the stem.

[0038] In embodiments, system further comprises a third gripper and a fourth gripper to hold a stem of a different plant. The first and second gripper can hold a scion, while the third and fourth gripper can hold a scion.

[0039] In embodiments, the blade subframe comprise a second blade. The blade and second blade on the subframe can be moved together using the blade drive. This allows simultaneous cutting of scion and rootstock.

[0040] In embodiments, the system preferably comprises a second stem support between the third and fourth grippers. Preferably the second stem support has a second elongated back support surface for support an elongated part of the stem of the different plant, wherein the second elongated support surface extends between the third and the fourth gripper. Preferably the second stem support comprises a second slit for receiving the second blade for cutting the stem of the different plant, wherein the slit extends across the elongated support surface. Preferably the slit and second slit are oriented parallel and wherein the blade and second blade mounted on the blade subframe, wherein the blades are oriented in parallel planes, [0041] In embodiments, the blade motor is arranged to move the blade subframe with blade and second blade into the slit and second slit.

[0042] In embodiments, the system comprises a third gripper drive, a fourth gripper drive and a second stem support drive. The system can be arranged to drive the third gripper drive to hold the stem of the different plant with the third gripper, to then drive the fourth gripper drive to hold the stem of the different plant with the fourth gripper, and to subsequently drive the blade motor to cut the stem of the different plant with the second blade.

[0043] In embodiments with the third and fourth gripper, the stem support drive is controlled to drive the second stem support and move the stem support between the third and fourth gripper, before cutting the different plant.

[0044] In embodiments, the first and third gripper drives are formed by a single gripper drive and the first and third grippers are coupled to that single gripper drive. In embodiments, the second and fourth gripper drives are formed by a single second gripper drive and the first and third grippers are coupled to that single second gripper drive. This allows simultaneous movement and use of a single motor. Also, the stem support drive and second stem support drive can be formed by a single stem support drive and the stem supports are coupled to that single stem support drive.

[0045] In examples, the first, second, third and fourth grippers are configured to align the stems of a scion-plant and a rootstock-plant along an axis parallel to said stems. This reduces the complexity for grafting the cut plant stems in a subsequent step.

[0046] In embodiments, multiple blades, and preferably multiple second blades, are connected to the blade subframe at proximal ends. This allows cutting several scions or several rootstocks, preferably scions and rootstocks, simultaneous in one cutting operation by operating the blade drive. Respective blade edges extend from the respective proximal ends to the respective distal ends of the respective blades. Preferably the blades are mounted on a single blade mounting body, Preferably the blade converges towards the blade distal end. [0047] Preferably the blade edges of the blade and second blade extend in parallel planes, facing each other. This allows cutting stems from opposite sides, resulting in opposite reaction forces that are reduced or cancelled. This increases the consistency of the cuts.

[0048] In embodiments, a distance between the blade edges of the blade and second blade increases towards the distal end. When the blade is moved in the distal direction, the blade edge will progressively be inserted into the stem that is cut.

[0049] The stem support can have an elongated gutter for receiving a part of the stem of the plant. By receiving the stem in a gutter, the stem can be supported from more side during cutting, which increases the reliability and consistency.

[0050] In examples, the elongated gutter extends over a part of the distance between the first and second gripper and forms the stem support surface.

[0051] The stem support can be formed by two stem support bodies. Preferably the slit is formed between the two stem support bodies. In embodiments, the stem support has a stem support body drive for moving the stem support bodies with respect to each other.

[0052] To further overcome drawbacks of the prior art, a method for preparing a plant stem for grafting is provided. The preparation method prepares stems by holding them for cutting. [0053] In embodiments of the method, stems of plants are provided. The stems have a free- end. The plant stems have been cut in a previous step to allow handling of the smaller plant. As a result of previous cutting, the free end extends. The free end can have a undefined position with respect to the rest of the provided plant. Moreover, the free end will, upon cutting, be able to move freely without resistance, which will reduce the effect of the actual cutting action. The method will prepare the plant stem by holding the free end of the plant for cutting.

[0054] In embodiments of the method, a first gripper holds the stem of the plant at a first location on the stem. A second gripper holds the stem of the plant at a second location on the stem closer to the free-end. The stem of the plant is subsequently cut at a location on the stem between the first and second locations. By supporting the free-end of the stem, the cut is ‘cleaner’. Bending away of the stem is prevented by the second gripper.

[0055] The method can further comprise supporting the stem at third and fourth locations at a distance between the first and second locations, and wherein cutting the stem comprises cutting the stem between the third and fourth. The third and fourth locations can be formed by a back stem support. Between the third and fourth locations, a slit is formed that can receive the blade. The third and fourth locations provide (back) support even closer to the cutting location and improve the consistency.

[0056] In embodiments, cutting can comprise moving a blade in a first direction through the stem, wherein the stem is supported on a backside with respect to the first direction.

[0057] In embodiments, the first, second, third and fourth locations are aligned along the stem of the plant.

[0058] In examples plant stems having a free-end are formed by scion-plants and rootstockplants. In embodiments, the scion plant is enclosed by the first and second gripper. The rootstock plant is held by a third gripper and a fourth gripper at a location on stem distant from the third gripper and closer to the free-end of the rootstock-plant. This will provide support during cutting of the rootstock, when cutting the stem of the rootstock-plant between the first and second location.

[0059] Embodiments of the method further comprise supporting the stem of the rootstock plant at third and fourth locations at a distance between the first and second locations, and wherein cutting the stem of the rootstock-plant comprises cutting the stem between the third and fourth locations. Preferably the blade is moved in a first direction through the stem of the rootstock-plant, wherein the stem of the rootstock-plant is supported on a backside with respect to the first direction.

[0060] In embodiments, the first, second, third and fourth locations for holding and supporting the rootstock- stem are aligned. Holding and supporting the rootstock stem at aligned positions results in a keeping the stem of the rootstock straight, which minimizes the risk of cutting the rootstock at an undesired angle. The resulting cutting surface extends in accordance with the preferred cut. In subsequent steps, the method comprises bringing together the cut ends of the scion-plant and the rootstock-plant and the differences between the to be grafted cut ends are minimized. In subsequent steps, the method comprises placing a graft element around the cut ends of the scion-plant and the rootstock-plant.

[0061] In embodiments, the held stem of the rootstock-plant and the held stem of the scionplant are cut simultaneously by first and second blades. A single operation, of moving the blade tool in a cutting direction, preferably into the slit formed between back-supporting locations of the held scion-plant and rootstock-plant, results in cutting. The blade tool with a pair of blades is driven through the held stems of the scion- and rootstock-plant respectively. In embodiments, the pair of blade and second blade are mounted on a blade subframe and driving the first and second blades comprises driving the blade subframe.

[0062] Preferably the first and second blades are driven in the first direction, while the held stems are held, and preferably aligned, in a second direction. Driving in a first direction perpendicular to the second direction, cuts the stems with the first and second blades.

[0063] Preferably cutting the stems results in a cutting surface on the stems that extends in a third direction. The third direction is sidewardly, preferably at angle of between 20 and 70 degrees with respect to the second direction. This results in a cutting surface on the stem that is similarly sidewardly, which has a larger surface area than a cut perpendicular to the second direction. Sidewardly is a direction that is rotated around the first drive direction of the cutting tool. To cut sidewardly, the blades extend in a surface that is rotated with respect to the driving or cutting direction.

[0064] Also proposed is, according to a further aspect of the disclosure, a system for grafting plant stems, wherein different tools one after the other to processing locations of the system for grafting stems.

[0065] In embodiments, the system for grafting plant stems comprises a first supply unit for supplying plant-stems-to-be-grafted. This first supply can receive plants and supply those plants as the rootstocks-to-be for grafting to the system. Receiving plants can comprise receiving bulk plants, trays of plants, plantlets, etc. Supplying can comprise the step of supplying the plants one by one, preferably in an ordered manner. Plant-stems-to-be-grafted can be plants, plant stems such as rootstock or scions, plant material, can include soil or substrate and can include a container or other holder.

[0066] In embodiments, the system for grafting plant stems comprises a second supply unit for supplying plant-stems-to-be-grafted. This second supply can receive plants and supply those plants as scions for grafting to the system.

[0067] In embodiments, the grafting system comprises a stem processing unit. At the stem processing unit plant-stems-to-be-grafted are received from the first and second supply units and subsequently those plant-stems-to-be-grafted are processed. In embodiments, the plant- stems-to-be-grafted are provided indirectly from the supply unit to the stem processing unit. Processing can include cutting and grafting, resulting in a grafted pair of stems. [0068] In embodiments, the grafting system comprises an output unit for outputting one or more grafted pairs of stems. The output unit can receive the grafted pairs of stems and position those on trays for growth or further shipping.

[0069] The grafting system disclosed herein can provide a system that receives the to-be- grafted materials and outputs the grafted pairs of stems, wherein a pair is formed from a rootstock and scion. This allows system that can operate without human intervention, which can reduce costs and/or increase reproducibility.

[0070] In embodiments, the grafting system further comprises a tool supply system. The tool supply system is arranged to supply tools to the stem processing unit. The tool supply system can be a controller that controls one or more drives. Operating the drive supplies, e.g. by moving, the tool to the stem processing unit. By moving the tool to the stem processing unit, the tool that is equipped for one or more tasks in the grafting process is made available at the stem processing unit and perform its one or more tasks close to the stem processing unit. The tool supply system can also be arranged to remove the tool from the stem processing unit. By removing the tool, the volume taken by the tool close to stems that were processed by the tool is free again and a next tool can be supplied for performing a next processing step. The tool supply system is arranged to supply one tool after removing the other tool.

[0071] In embodiments of the invention, the tool supply system includes at least a cutting tool configured to cut the plant-stems-to-be to form one or more pairs of scions and/or rootstocks. The cutting tool is arranged to perform the process of cutting the plant-stems-to- be-grafted that were supplied to the stem processing unit and can perform that task of cutting near or close to the stem processing unit. In embodiments, already cut plant-stems-to-be- grafted are cut by the cutting tool. This provides pre-cut plants with free ends, which are more easily processed. The cutting tool is preferably arranged to cut plant-stems-to-be- grafted to form at least one pair of a scion and a rootstock. In preferred embodiments multiple pairs of scion and rootstocks are formed by cutting. Cutting the plant-stems-to-be-grafted can comprise performing the final cut before the plant-stems-to-be-grafted are grafted in a next step. After cutting, the cutting tool may be removed from the stem processing unit by the tool supply system. Removing the cutting tool from the stem processing unit in this manner may provide space for another tool and/or other tools to be supplied to the stem processing unit. [0072] In embodiments of the invention, the tool supply system includes at least a grafting tool configured to graft pairs of stems of rootstocks and stems of scions with graft elements. The grafting tool is arranged to perform the process of grafting the plant-stems-to-be-grafted, preferably after cutting the plant-stems-to-be-grafted. The grafting process, e.g. by providing a grafting element to graft at least one pair of a scion to a rootstock is performed at, near or close to the stem processing unit, preferably at adjacent processing locations provided in the stem processing unit.

[0073] In embodiments, two or more plant-stems-to-be-grafted are held at adjacent processing locations in the stem processing unit. This allows processing two or more stems at a distance from each other at the same time. This increases the processing speed. The first and second supply unit can supply the plant-stems-to-be-grafted to the processing locations. [0074] Preferably, individual plant-stems-to-be-grafted are supplied and held at the adjacent processing locations of the stem processing unit. Preferably, the stem processing unit provides at least two or more adjacent grippers arranged to hold plant-stems-to-be-grafted received from the first and second supply units. The supplies direct the plant-stems-to-be- grafted to processing locations at the stem processing unit and subsequent processing is performed on the plant-stems-to-be-grafted at those processing locations. This reduces the (relative) movement of the plant-stems-to-be-grafted to supplying them to the processing locations. Subsequent processing can be performed at the processing location. Although embodiments will be described with a fixed processing location, the processing location can be a moving, preferably continuously moving, location on the stem processing unit or in the grafting system.

[0075] Preferably, the stem processing unit provides two rows of processing locations. A first row of plant-stems-to-be-grafted can be formed by scions-to-be, a second row by rootstocks-to-be. This allows processing of rootstock and scions simultaneously. Preferably, the processing comprises processing (such as cutting or grafting) at least two or more pairs of scions having stems that are held generally aligned with stems of rootstocks at each of the processing locations.

[0076] In embodiments, the cutting tool is configured to process, preferably at adjacent positions, two or more plant-stems-to-be-grafted, with each pair comprising a rootstock-to-be and a scion-to-be. This allows the simultaneous cutting of multiple stem pairs by a single cutting tool. Preferably, cutting of adjacent stems is performed simultaneously by individual blades at respective adjacent processing locations. The cutting tool can have a row of adjacent blades.

[0077] In embodiments, the grafting tool is configured to process at adjacent processing positions two or more pairs of plant stocks, with each pair comprising a rootstock and a scion with a graft element. This allows grafting of multiple stems by a single grafting tool. Preferably grafting of adjacent stems is performed simultaneously by individual grafting units that simultaneously provide respective grafting elements to pairs of scions and rootstock. In embodiments, the cutting tool will have pairs of blades at adjacent positions for cutting multiple pairs.

[0078] In embodiments, the tool supply system further includes a transfer tool. The transfer tool can be a tool for preparing the plant-stems-to-be-grafted. In embodiments, scions will be prepared using the transfer tool The transfer tool can transfer supplied plant-stems-to-be- grafted from the first or second supply unit to the processing locations at the stem processing unit. The transfer tool can receive the plant-stems-to-be-grafted and transfer them to the processing locations. Preferably, multiple plant-stems-to-be-grafted are simultaneously transferred in one action. The transfer tool is, after picking-up plant-stems-to-be-grafted, moved to the stem processing unit after removing the tool the performed the previous process, such as the grafting tool or the cutting tool. The transfer tool is removed from the processing locations and from the stem processing unit after transferring the plant-stems-to- be-grafted to the stem processing unit, thus providing space for another tool or other tools to be supplied to the stem processing unit. After removing the transfer tool from the processing unit, the tool supply system is arranged to supply tools comprising the cutting tool and transfer tool to the processing unit. In embodiments of the invention, the tool supply system is arranged to sequentially supply and remove tools, such as the cutting tool and grafting tool and/or transfer tool, to the stem processing unit. The tool supply system may be arranged to supply a transfer tool to transfer at least some of the plant-stems-to-be-grafted to the stem processing unit. After a transfer tool has transferred at least some of the transferring plant- stems-to-be-grafted to the stem processing unit, the tool supply system may be arranged to remove the transfer tool from the stem processing unit. Removing the transfer tool from the stem processing unit provides space for other tools to be supplied to the stem processing unit. [0079] In embodiments, the second supply unit is arranged to supply plants for scions, wherein the transfer tool is configured to cut at least one, preferably two or more, stems of the supplied plants from the second supply unit. The cut plant held by the transfer tool can form a scion to be grafted. The transfer tool is configured to transfer the at least one scion to the stem processing unit. Also, the first supply unit can cut the plant stems supplied to the stem processing unit. Pre-cutting, which is cutting the stem before the stem is positioned at the processing locations of the stem processing unit, allows supplying pre-cut scions and/or rootstocks-to-be to the stem processing unit. The pre-cut plant-stems-to-be-grafted will have a free end. By removing a part of the plant before processing in the stem processing unit, handling of the plants is made easier. In embodiments, the tool supply system comprises two or more transfer tools. For example, a first transfer tool of the two or more transfer tools may be supplied by the tool supply system to transfer a first plurality of supplied plant-stems-to- be-grafted from the first or second supply unit to the processing locations at the stem processing unit. Concurrently, a second transfer tool of the two or more transfer tools may be used to receive a second plurality of plant-stems-to-be-grafted. The tool supply system may be arranged to remove the first transfer tool of the two or more transfer tools when the first transfer tool of the two or more transfer tools has transferred the first plurality of plant-stems- to-be-grafted from the first or second supply unit to the processing locations at the stem processing unit. Similarly, the second transfer can be move and removed to the processing locations. The transfer tool picking-up plant stems from the supply unit can be filled, while the other transfer tool is supplying to the processing locations.

[0080] In embodiments, the transfer tool is configured to localize a node on the stem of the scion at which one or more leaves are formed. By localizing the node, mechanically or electronically, the node of the scion can be used as a reference for cutting the stem for subsequent grafting. In embodiments, the stem of the scion is cut at a predetermined distance from the determined node. This results in scions with a predetermined length, which will increase the similarity in a batch of grafted plants which share the same scion length. The transfer tool can be configured to engage the stem of the scion at a predetermined location, preferably a predetermined location with respect to a reference, wherein preferably the reference is the node.

[0081] In embodiments, the tool supply system and the transfer tool are arranged to transfer the scion to the stem processing unit such that the stem processing unit engages the stem of the scion at a predetermined location. In embodiments, the determined position of the node is transferred to the stem processing unit. By using the transfer tool, the stem processing unit receives the stems in accordance with a predetermined protocol. E.g. the stem processing unit will receive scions from the transfer tool and engage those transferred scion at a distance of 2 mm from the determined node. This allows to perform subsequent processing, such as further cutting or grafting, at predetermined locations on the scions. Preferably, each predetermined location is with respect to a reference, wherein preferably the reference is the node of the scion.

[0082] In embodiments, the grafting system comprises a frame. In embodiments, the grafting system comprises modules. In embodiments, the first supply unit, the second supply unit, output unit and the stem processing unit are modules that are couplable. In embodiments, the first supply unit, the second supply unit, output unit, the stem processing unit and the tool supply system are mounted on the grafting frame. By providing modules, smaller units are provided. The modules can be coupled to form the grafting system. By coupling the modules, the modules are positioned with respect to each other in the grafting system.

[0083] In embodiments, the tool supply system preferably comprises one or more drives for moving the cutting tool, for moving the grafting tool, and preferably for moving the transfer tool, with respect to the frame. By controlling the drives, the respective tools can be moved. By controlling the drives the tools can be moved to and from the processing locations one after the other. In embodiments, the one or more drives are arranged to move and remove the cutting tool, grafting tool, and preferably the transfer tool, from one or more processing locations at the stem processing unit. In embodiments, the one or more drives are arranged to supply a transfer tool arranged to transfer plant-stems-to-be-grafted, preferably scions, to the stem processing unit and subsequently remove the transfer tool after transfer of plant-stems- to-be-grafted by the transfer tool, the one or more drives being further arranged to a supply a cutting tool arranged to cut plant stems and subsequently remove the cutting tool after and/or during plant-stems-to-be-grafted have been cut with the cutting tool, the one or more drives being further arranged to supply a grafting tool arranged to graft plant stems and subsequently remove the grafting tool after and/or during plant-stems-to-be-grafted have been grafted with the grafting tool.

[0084] In embodiments, the cutting tool and/or the grafting tool and/or the transfer tool comprises a cutting/grafting/transfer subframe. The subframe can be mounted to the respective drives, which can be embodied by a robot arm. In embodiments, the subframe is guided by a guide, e.g. a horizontal guide. The subframe allows positioning the respective processing unit, such as blades, graspers, etc. at desired locations. The subframe with multiple processing units can be moved by operating the drive.

[0085] Having one or more conveyors or tracks in the first/second supply unit and in output unit can be advantageous. The conveyors can provide separated plant support locations. This allows supporting individual plant-stems-to-be-grafted from the supply to the output unit, via the stem processing unit. In preferred embodiments, the first supply unit and the output unit share a conveyor or track. At the first supply units, rootstocks including a container are positioned on the conveyor and are transported in the grafting system via the stem processing unit to the output unit. By providing a shared conveyor, manipulation of the supplied plant stems is reduced.

[0086] In embodiments, the stem processing unit has adjacent processing locations for stems of plants, wherein the adjacent processing locations align with plant support locations on the first supply unit and/or the output unit. This allows for providing the plant-stems-to- be-grafted at individual locations to the individual processing locations for processing. This allows simultaneous processing. Simultaneous processing may be performed on adjacent plants and/or plant-stems-to-be-grafted comprising rootstocks and/or scions which may be disposed in rows and/or at adjacent processing locations, preferably processing locations which are at a predetermined distance and/or predetermined distances from each other.

[0087] In embodiments where the grafting system comprises the transfer tool for transferring plant-stems-to-be-grafted from the second supply unit to the stem processing unit, the transfer tool can be arranged to have multiple transfer positions that align with plant support locations on the conveyor of the second supply unit. The transfer tool can then engage multiple plant-stems-to-be-grafted at a distance from each other in one operation. The multiple transfer positions align with processing locations in the stem processing unit. This allows transferring the grasped plant-stems-to-be-grafted to each of the processing locations of the stem processing unit.

[0088] In embodiments, the first supply unit, and preferably the second supply unit, comprise a load unit for loading each plant support locations with plants for scions and rootstocks for grafting. The load unit can be a robot arm. The load unit can transfer provided plant material at the input of the supply units to the conveyors with plant support locations. The load unit can load one, in some embodiment scanned by imaging and approved according to predetermined quality parameters, plant-stem-to-be-grafted onto a plant support location. Once a plant support location is filled, a next, adjacent plant support location is supplied with the next plant stem by the load unit. This ensures that a row of filled plant support locations is provided to the downstream processing devices in the grafting system. In embodiments, the system can comprise multiple first supply units. Part of the first supply unit can be a robot arm to position plants in holders. Supplying can comprise the step of supplying several plants and/or plant-stems-to-be-grafted stems simultaneously and/or supplying several plants and/or plant-stems-to-be-grafted disposed in a row and/or in rows with the plants or plant-stems-to-be-grafted disposed at adjacent locations, e.g. in holder connected by a chain, wherein preferably the adjacent locations are at a predetermined distance and/or predetermined distances from each other. In embodiments, the system can comprise multiple second supply units. Part of the second supply unit can be a robot arm to position plants in holders. Supplying can comprise the step of supplying several plants and/or plant-stems-to- be-grafted stems simultaneously and/or supplying several plants or plant-stems-to-be-grafted disposed in a row and/or in rows with the plants or plant-stems-to-be-grafted disposed at adjacent locations, e.g. in holder connected by a chain, wherein preferably the adjacent locations are at a predetermined distance and/or predetermined distances from each other. [0089] In embodiments, the stem processing unit has one or more scion processing locations and one or more rootstock processing locations. The one or more scion processing locations and the one or more rootstock processing locations can have one or more grippers for gripping the scion and rootstock respectively. By holding the scions and rootstocks at the processing locations, tools can be supplied to those processing locations for performing their respective processes. In this application, gripping or grasping includes enclosing, engaging, holding and any manipulation which results in holding a predetermined position.

[0090] In embodiments, the one or more grippers for gripping the scions and rootstocks are aligned along a direction of the stems. A rootstock is held by bottom grippers, whereas the scion is held by top grippers and the stems of the held rootstock and held scion generally align.

[0091] In embodiments, the one or more grippers for gripping the scions and/or rootstocks are moveable towards and away from each other. This allows first gripping/engaging/enclosing the stem at a first location and subsequently moving the grippers apart, while holding/enclosing the stem, resulting in gripping the stem at two separate locations. The one or more grippers for gripping the scions are moveable in the direction of the stem towards the one or more grippers for gripping the rootstocks. The stem is held at two separate locations and grippers at those locations can align the stem in a direction, preferably a vertical direction. The one or more scion processing locations and one or more rootstock processing locations are aligned, wherein preferably the stem processing unit is arranged to align stems of one or more pairs of scion and rootstock at the processing locations.

[0092] By gripping the scion and/or rootstock at the processing locations, a subsequently supplied tool, preferably supplied by the tool supply system, can operate on that stem at a predetermined location. When the scions and rootstocks are held aligned, the cutting tool can comprise one or more pairs of blades at adjacent processing locations. The pair of blades is arranged to cut the scion and the rootstock engaged by the stem processing unit. The blade pair is held in a parallel alignment and can cut the aligned scion and rootstock, preferably simultaneously, by a shared movement, operated by a drive. As a result of the stems of the rootstock and scions being aligned and cutting with an aligned blade set, aligned cutting surfaces are obtained, leading to better grafting results. Cutting plant-stems-to-be-grafted may comprise cutting multiple plants and/or plant-stems-to-be-grafted and/or pairs of aligned plant-stems-to-be-grafted simultaneously. Simultaneous cutting may be performed on adjacent plants and/or plant-stems-to-be-grafted comprising rootstocks and/or scions which may be disposed in rows and/or at adjacent cutting locations, preferably cutting locations which are at a predetermined distance from each other.

[0093] The grafting tool can comprise in embodiments one or more graft element applicators at adjacent processing locations, graft element applicators arranged to connect the scion and the rootstock engaged by the stem processing unit. Grafting plants and/or plant stems can comprise grafting multiple plants and/or plant stems simultaneously by the grafting tool supplied by the tool supply system. Simultaneous grafting can be performed on adjacent plants and/or plant-stems-to-be-grafted comprising rootstocks and/or scions which may be disposed in rows and/or at adjacent grafting locations, preferably grafting locations which are at a predetermined distance and/or predetermined distances from each other. The grafting locations may comprise at least in part the same positions as the processing locations and/or the cutting locations.

[0094] In embodiments, the stem processing unit has one or more stem processing locations, which have one or more grippers for holding the plant stem. The tool supply system can be arranged to supply and remove one or more tools to that one or more stem processing locations by supplying and removing the tool in and from two generally opposite direction to the one or more processing locations. A conveyor track supplying rootstocks at the processing locations can extend in a first horizontal direction. The stems are then generally directed in the vertical direction. Tools can be supplied from and removed in a second horizontal direction, generally perpendicular to the first horizontal direction. The second horizontal direction allows approaching the processing location from two sides. E.g. for cutting, a blade can be supplied in one direction, whereas a stem support that supports a backside of the stem to be cut can be provided from the opposite direction. This anti-tool aides the desired tool process. Th opposite second horizontal directions are generally perpendicular to a direction of the stem held by the one or more grippers.

[0095] In embodiments, the tool supply system is arranged to remove one tool, before supplying a next tool. In embodiments, the cutting tool and the grafting tool are mounted on cutting and grafting subframe at distant positions on that subframe. A cutting and grafting subframe drive is arranged to supply and remove the cutting tool to the stem processing unit and is arranged to supply and remove the grafting tool to the stem processing unit. By providing the cutting tool and grafting tool on a shared subframe at distant positions, moving the grafting tool to the processing location results in removing the cutting tool from those processing locations and vice versa.

[0096] In embodiments, said cutting and grafting subframe is guided in a plane, e.g. in a guide mounted on the frame of the grafting system, generally perpendicular to a direction of the plant stem held by the stem processing unit.

[0097] In embodiments, the grafting system comprises a vision control system. The vision control system comprises a camera, image processing and predetermined parameters that can be compared with the obtained images. The vision control system on a supply unit is arranged to guarantee that only correct plants are fed into the system. In embodiments, the output unit is equipped with a vision control system to monitor the grafting results.

[0098] The application also provides a method for grafting plant stems. According to an aspect of the invention disclosed herein, the method comprises providing and plant-stems-to- be-grafted at one or more plant stem processing locations, e.g. in a stem processing unit. Tools for performing respective processing steps of the stems at those stem processing locations can be supplied and removed. By supplying two or more tools with different desired processing, those tools can be complex and can perform the desired operation in a desired manner. By providing those tools one after the other, that is a next tool is supplied only after removing the previous tool from the processing location, sufficient space is available to position the tool close/near/at the processing locations where the stems are being held. In an embodiment of the method, tools are provided to two or more adjacent stem processing locations, allowing to process multiple adjacent stems in one process with the supplied tool. In an embodiment of the method, plants-to-be-grafted are cut to for scions-to-be and rootstocks-to-be. Those scions-to-be and rootstocks-to-be are supplied and held as a pair at the one or more stem processing locations. At that stem processing location, the supplied cutting tool and the supplied grafting tool then process that pair to cut the scion-to-be and rootstock-to-be in one or more pairs of scion and rootstock and to then graft those one or more pairs.

[0099] In embodiments, the transfer too, cutting tool and grafting tool are supplied and removed from the processing locations one after the other. A transfer tool is supplied to processing locations, the transfer tool transfers plant-stems-to-be-grafted, preferably scions, from the first or second supply unit to the processing locations at the stem processing unit. The transfer tool is subsequently removed. A cutting tool is supplied to the processing locations, the cutting tool cuts the one or more plant-stems-to-be-grafted held at the processing locations. The cutting tool is subsequently removed. The grafting tool is subsequently supplied to the processing locations with the cut plant-stems-to-be-grafted and the grafting tool grafts those cut stems. Subsequently the grafting tool is removed, e.g. before supplying the cutting tool again.

[00100] In embodiments, the method comprises supplying a cutting tool to the one or more plant stem processing locations, and cutting the plant-stems-to-be-grafted held at those stem processing locations. In embodiments, the method further comprises supplying a grafting tool to the one or more plant stem processing locations, wherein the grafting tool is supplied after removing the cutting tool. The grafting tool then grafts a pair of cut plant stems.

[00101] In embodiments of the method, several plant stems are held at adjacent plant stem locations. The plant stem locations are separate, at a distance from one and other. This allows supplying several adjacent plant stems to those locations. The cutting and grafting steps can then also comprise cutting and grafting multiple plant stems simultaneously. In embodiments, the plant-stems-to-be-grafted are cut and/or grafted generally simultaneously in the adjacent plant stem locations. The cutting tool can simultaneously cut three or more stems. The cutting tool and/or grafting tool can have similar processing locations with multiple cutters or grafters at a distance from one and other.

[00102] In embodiments, several plant stems are held in two rows of adjacent plant stem locations. This allows holding a row of scions and holding a row of rootstocks. In embodiments, the stems of the scions and rootstocks are held generally aligned. The method can comprise moving plants stems held in the first row towards plant stems held in the second row. The stems can be cut before moving. After moving the stems toward each other the stems can be grafted.

[00103] In embodiments, the plant-stems-to-be-grafted are cut and/or grafted generally simultaneously in the adjacent plant stem locations. The two rows of adjacent plant stem locations can also be simultaneously processed, such as cut or grafted. Simultaneous cutting of two rows of multiple stems can be performed by using, e.g. pushing, several pairs of blades into the stems. A first blade in the pair of blades cuts the plant stem held in first row and the second blade in the pair of blades cuts the plant stem held in the second row. This simultaneously cuts scions and rootstocks. By providing the pairs of blades on a single structure, such as a blade subframe, the pair of blades can be in a predetermined orientation, e.g. aligned. By then moving the blade subframe, the aligned pair of blades makes a parallel movement, which can result in a parallel cutting surface on the stem ends. Those parallel cutting surface can then be grafted. Preferably, the grafted pair of cut plant stems is formed from a scion from the second row and a rootstock from the first row, and several grafted pairs of cut plant stems are grafted simultaneously in adjacent plant stem locations,

[00104] In embodiments, plant-stems-to-be-grafted are provided by supplying plant stems, cutting the plant stems, and holding the cut plant stems at one or more plant stem processing locations. The cut plant-stems-to-be-grafted preferably form scions for the to be grafted plants.

[00105] The method can further comprise transferring the cut plant stems to the plant stem processing locations. In embodiments, plant-stems-to-be-grafted are supplied in the grafting system, e.g. on a conveyor or on a track. To hold scions in the processing locations, the supplied plant-stems-to-be-grafted are transferred, which transferring action can comprise cutting the plant-stems-to-be-grafted to obtain scions, that is plant material without a root. By the extra step of transferring, the scions can first be processed while still being connected to the root and embedded in soil or in substrate. This increases the preservation. Upon transferring, a last step before holding the scions in the stem processing unit, before cutting and grafting, scions are formed and thus the time of the scion being disconnected from the root is minimized.

[00106] In embodiments, the transferring comprises two or more supplied plant stems that are cut. The cut plant stems are transferred to two or more adjacent stem processing locations simultaneously. This increases the capacity and productivity.

[00107] Two or more supplied plant stems are transferred preferably after removing grafting tool from the processing locations. This allows approaching the held plant-stems-to-be- grafted in at the processing locations by the tools from the same side. Removing the previous tool makes space for the next tool.

[00108] In the method comprising the transfer of scions to the processing locations, the cut plant stem is held at a predetermined position, preferably with respect to a reference, which is preferably formed by a node at which leaves are formed on the plant stem. By holding the cut scions in a predetermined position, e.g. just below the node, the scions can be positioned in the grippers of the processing location with a predetermined position or orientation, e.g. at 2 mm below the node. In embodiments, transferring the held cut plant stems comprises taking over the held cut plant stems at the plant stem processing locations at a predetermined position, wherein preferably the predetermined position is with respect to a reference, preferably with respect to a node of leaves on the plant stem. This results in the scions being held at the processing location in a predetermined position with respect to the node, and subsequently cutting the scion at 5mm from the node is possible. This results in scions of the same length, creating batches of grafted plants with similar properties. Consistency of the grafted plants is increased.

[00109] In embodiments, supplying the grafting tool after removing the cutting tool comprises driving the grafting tool and cutting tool, both mounted on a grafting and cutting subframe. By mounting the cutting tool and grafting tool on a shared subframe, they can be moved together. In embodiments, driving of the grafting and/or cutting tool comprises moving the tools simultaneously in a first direction generally perpendicular to the plant stem direction and in second direction, preferably opposite to the first direction. The tools can move synchronously. Moving the cutting tool simultaneously results in removing the grafting tool or vice versa. [00110] In embodiments, supplying and removing the grafting tool and the cutting tool comprises driving the grafting and cutting tool in a direction generally perpendicular to a direction of the held plant stems at the plant processing location. Preferably, the supply and removal of tools comprises or is limited to moving the tools in a generally horizontal direction. The stems are generally held in a vertical direction. However, other orientations, but with similar perpendicular orientations are possible.

[00111] In embodiments, providing plant-stems-to-be-grafted comprises supplying plant stems held in a container, preferably conveying the containers with plant stems. By conveying the plant-stems-to-be-grafted, the impact on the stems is reduced. The supplied plant stems held in containers can be supplied to adjacent stem processing locations, e.g. a row of processing locations. The plant-stems-to-be-grafted can be supplied with a separation distance that corresponds to the distance between adjacent stem processing locations. This allows aligning the supply or conveyor with the processing location. In embodiments, the rootstocks are supplied and held in the processing locations, while the container of the rootstocks is positioned in the support locations of the convey or/track.

[00112] In preferred embodiments, scions are grafted onto the rootstocks held in the container and the grafted plant is transported further, while remaining inside the container. This allows continuous support with little impact on the stem. Support is provided via the container. In embodiments, a supply line for rootstocks extends from the upstream supply unit to the downstream output unit along the stem processing unit. Using a single supply line, potentially comprising multiple separate joined parts, has minimal impact on the stems. [00113] Also proposed is, according to a further aspect of the disclosure, a holding tool for engaging a stem of a plant with a gripper. The gripper encloses the stem. The stem is a stem of a plant-to-be-grafted. The stem is enclosed, and could be constrained, but can also be free to move in the gripper enclosing the stem. Under the influence of an external force or by a predetermined action, the stem can move with respect to the gripper. The stem has a node at which leaves are formed. The enclosure space that surrounds the stem is smaller than the node and the gripper will run into and engage the node. This positions that gripper with respect to the node of the plant. As a result, the gripper is positioned with respect to a reference, the node of the stem. Positioning the gripper with respect to the node can subsequently be used to position the holding tool and the held plant stem for subsequent processing. According to this aspect, the enclosure space is dimensioned to surround the stem and is dimensioned to engage a node of the stem, wherein the holding tool comprises a holding tool drive for driving the gripper in the enclosed state in a direction substantially parallel to and along the stem of the plant. This allows moving the gripper enclosing the stem to a position close to the node.

[00114] In embodiments of the holding tool, the holding tool has grippers that can move with respect to each other increasing, and in an embodiment decreasing, the distance between the individual grippers, while holding the stem of that plant. Stems can be held by a first gripper, which can comprise enclosing, engaging, constraining, grasping. A second gripper can then be brought to a state of holding the stem already held by the first gripper by mechanically positioning that second gripper close to where the first gripper is already holding the stem. The location of the held stem is determined by the grip of the first gripper. The second gripper can then be moved away from the first gripper, preferably parallel to and along the direction of the same stem, to engage the same stem at a different location. This results in the first and second gripper holding the stem at two different locations along the length of the stem. Preferably the gripper drive is arranged to move the first gripper with respect to the second gripper with the stem enclosed by the first gripper and by the second gripper, in the direction parallel to the aligned enclosure spaces. This ascertains that the stem remains held. One of the grippers is moved along and relatively to the stem.

[00115] In embodiments, the holding device comprises a first gripper and a second gripper. The first and second grippers are arranged to form a first and second enclosure space, preferably around the stem of the same plant, respectively. The first and second enclosure spaces are each adapted to the size of the stem to be held.

[00116] In embodiments, the enclosure space will surround the stem. In an embodiment, the enclosure space is O-shaped or C-shaped or has a different shape that at least partially surrounds the length of the stem. In embodiments, the first or second enclosure space is circular-, triangular-, rectangular-, pentagonal-, hexagonal and/or multigonal in cross section extending in a stem direction.

[00117] The stem will have a length direction. The enclosure space extends in the length direction of the enclosed stem. In directions perpendicular to the length direction, the enclosure space will be larger than the cross-section of the stem to be held. Preferably the size of enclosure space is 10%, 20% or 30% larger than the stem’s cross-section. This will allow surrounding the stem without constraining the stem. This reduced the force on the fragile stem. In other embodiments, the enclosure space is sized to correspond or be smaller than the thickness of the stem. In embodiments, the enclosure space can be varied in sized. In embodiments, the size of the enclosure space is in dependent of measurements of a force exerted on the stem. For example, the higher the force, the larger the enclosure space. Preferably, the enclosure space is sized down incrementally up until the force exerted on the stem passes a certain threshold, the threshold e.g. indicating that further increasing the force on the stem will result in squishing. The first and second enclosure spaces can be sized differently.

[00118] By enclosing the stem without constraining the stem, the stem is supported and held in the enclosure. Under the influence of external forces, such as the gravity, the stem can be forced into a direction, e.g. downward. The top gripper will, when the stem drops downwards or when the top gripper is moved upward run into the node of the plant closest to the roots. At the node the stem widens. The enclosure space is such that the gripper cannot move beyond the node. As a result, the second gripper engages the node. This in turn result in the second gripper being positioned with respect to a reference of the plant, namely the node. In subsequent actions the predetermined position of the second gripper with respect to the node can be used for positioning the enclosed plant or can be used for processing the stem, e.g. at a predetermined distance from the determined position of the node.

[00119] In embodiments, the first and second enclosure spaces enclose the stem of a plant therein and the first and second enclosure spaces are generally aligned along a direction parallel to the stem. This allows enclosing the stem with a first gripper and subsequent with the second gripper at almost the same location on the stem.

[00120] According to embodiments of aspects of the invention, the holding tool comprises a gripper drive arranged to move the first gripper with respect to the second gripper in the direction parallel to the aligned enclosure spaces. As a result, the distance between the grippers, in a direction parallel to the stem, can be increased, or decreased. The locations for holding the stem can as a result be adapted after enclosing the stem.

[00121] In embodiments, the holding tool is arranged to enclose the stem of the plant with the first gripper and subsequently enclose the stem of that plant with the second gripper. This allows first enclosing the stem at a first location and subsequently moving one of the two grippers to a second location along the stem. In embodiments, the second enclosure space is formed adjacent to the already formed first enclosure space along the direction of the stem of the plant. In embodiments, the holding tool comprises a gripper drive, wherein the gripper drive is arranged to move the first and second gripper a predetermined distance apart. In embodiments, the holding tool is arranged to first form the first and second enclosure space and to subsequently move the first and second gripper apart parallel to and along the direction of the stem of the plant.

[00122] In embodiments, the second enclosure space is larger than the first enclosure space. This is helpful, when the second gripper is moved to move over and along the stem. With a larger enclosure space, the friction with the stem, if any, is reduced.

[00123] In embodiments, the first gripper is arranged to engage the stem with a higher force than the second gripper. This allows constraining the stem with the first gripper, while moving the second gripper to a desired location along the stem.

[00124] In embodiments, the first gripper comprises first gripping elements. These gripping elements can be fingers or elongated elements that can be opened and closed for enclosing a stem between the gripping elements. In embodiments, the first enclosure space is formed between the first gripping elements of the first gripper. In embodiments, the second gripper comprises second gripping elements, wherein the second enclosure space is formed between the second gripping elements of the second gripper.

[00125] In embodiments, the holding tool comprises at least one gripping element drive arranged to move a gripping element of the gripper with respect to other gripping element of the gripper. A controller can be provided that is arranged to operate the drive. The enclosure space is formed between the gripping elements moved in the holding state.

[00126] In embodiments, the holding tool further comprises a blade for cutting the stem for grafting. The blade can cut an enclosed stem. The remaining stem can be a rootstock or a scion or can be plant-stem-to-be-grafted or a prepared state. In embodiments, the blade is arranged to cut the stem at a predetermined distance from the first or second gripper, preferably a predetermined distance from the node of the plant.

[00127] In embodiments, the first gripper is arranged to step-by-step enclose, preferably constrain, one or more degrees of freedom of the stem of plant. By subsequently arranging grippers around the stem, this is achieved.

[00128] In embodiments, the first gripper is arranged to enclose the stem of plant in direction perpendicular to the stem and subsequently in a direction parallel to the stem. [00129] In embodiments, the step-by-step enclosing and constraining with the first gripper encompasses gripping elements and a pushing element. On top of the gripping elements that provide the enclosure space, the pushing element can move to reduce the size of the enclosure space, e.g. dependent on the size of the stem.

[00130] In embodiments, the first gripper further comprises a pushing element to enclose or engage or constrain the stem in the first enclosure space. The enclosure space is reduced, or enlarged, preferably in a direction perpendicular to the stem. The pushing element can be guided between the gripping elements. In embodiments, the pushing element drive is arranged to move the pushing element towards first enclosure space, wherein preferably the first enclosure space is formed between first gripping element of the first gripper. A drive can move the pushing element. In embodiments, the pushing element is arranged to move in a plane perpendicular to the alignment of the enclosure spaces.

[00131] In embodiments, the pushing element comprises a flexible element on a distal end. The pushing element can have a flexible tip on a surface directed at the stem. The pushing element can be coupled to a gauge or force meter to prevent the pushing element to exert to high force on the stem.

[00132] In embodiments, the holding tool comprises a sensor arranged to sense whether the first or second gripper engage the node and/or the one or more leaves of the plant on the stem.

[00133] According to further aspects, a processing system for scions for grafting. The processing system is adapted to process and prepare scions for grafting. A supply unit provides plants and a holding tool encloses the supplied tool, wherein a gripper of the holding tool is positioned with respect to a reference of the plant, e.g. the node of the plant.

[00134] Embodiments of the scion processing system have a supply unit, such as a conveyor, for feeding plants with stems for providing scions for grafting, and the holding tool according to any of the embodiments described in this application. The holding tool is fed with plants with stems. The conveyor is arranged to supply plants to the holding tool. The supply unit is arranged below the holding tool as the supply unit supports the containers holding the stems and stems extend upwards.

[00135] In embodiments of the scion processing device, the holding tool further comprises a blade for cutting the stem to form a scion for grafting. The blade allows separating a scion from a supplied plant. The separated scion can then be fed to subsequent downstream processing, which can include further cutting for grafting the scion.

[00136] In embodiments, the supply unit or conveyor of the scion processing device has plant locations at a predetermined spacing. This allows supplying individual plants to provide individual scions. In embodiments, the holding tool comprises two or more sets of grippers at distances that correspond with the predetermined spacing. In embodiments, the two or more sets encompass first and second grippers, each positioned at the corresponding predetermined spacing. A set of grippers separated by a predetermined spacing can enclose plant stems supplied at that same predetermined distance.

[00137] According to a further aspect of the invention, a grafting system is provided for grafting plants that comprises the processing system according to any of the embodiments disclosed herein. The grafting system can comprise the supply unit for supplying scions and rootstocks and can comprise grafting tool for grafting scions and rootstocks supplied thereto. The holder tool allows enclosing the stem and cutting the stem between the grippers that have moved a certain distance apart.

[00138] In embodiments, the holding tool is mounted on a robot arm. This allows moving the robot arm with holding tools to positions for operating or processing supplied plant-stems-to- be-grafted.

[00139] According to a further aspect, a method for holding a plant stem is provided. The holding method comprises providing a plant having a stem with a node with one or more leaves. In the method, a gripper that encloses the stem is moved to engage the node. As a result, said gripper, and the holding tool as a whole, are positioned to a reference, formed by the node of the plant that is being held.

[00140] In embodiments, the method comprises enclosing the stem with first and second grippers. This allows gripping the plant stem at two locations. In an initial step the second gripper can be positioned very closely to the first gripper. By first enclosing the stem with the first gripper, the second gripper can be positioned around the stem with the already defined position.

[00141] In embodiments of the method, preferably the scion holding method, the method includes moving the first and second grippers relatively away from each other in a direction parallel to and along the direction of the stem. This allows moving a gripper that encloses the stem along the stem to a different location enclosing the stem. [00142] In embodiments, the method also comprises lifting the plant by its node and/or one or more leaves by a predetermined distance. Supplied plants with roots can be enclosed by the gripper and that gripper can be moved away from the roots and will collide with the node. As the enclosure space is dimensioned to enclose the stem without constraining but is not dimensioned to move over the node, the node will act as a stop. If the gripper is moved further, the node will be moved, e.g. lifted against the gravitational force. Lifting can comprise lifting the plant and lifting the container with substrate.

[00143] In embodiments, the method also comprises cutting the stem of the plant at a predetermined position on the stem. By positioning the gripper with respect to the node, a blade can cut the stem at a distance from that gripper that is positioned with respect to the node. This can result in stems being cut at a predetermined distance from the node. Scions with stems of generally the same length are beneficial in providing a batch of grafted plants. Scions of similar lengths will result in the grafted plants having similar lengths.

[00144] In embodiments, enclosing the stem with the first gripper comprises forming an enclosure space with a first and second gripping elements of the first gripper. Enclosing can comprise approaching the stem from two sides, e.g. using two gripper elements. One element or both elements can move from an opened state to an enclosing or holding state.

[00145] In embodiments, enclosing the stem with the first gripper comprises forming an enclosure space with a first and second gripping elements of the first gripper forming a circular-, triangular-, rectangular-, pentagonal-, and/or hexagonal-enclosure.

[00146] In embodiments, the first enclosure space is further formed by a pushing element, wherein the pushing element is arranged to move such that the enclosure space is reduced or enlarged, preferably in a direction perpendicular to the stem.

[00147] In embodiments, the method also comprises sensing, using at least one sensor coupled to the first gripper, whether the first gripper engages the stem, node and/or the one or more leaves of the plant.

[00148] In embodiments, the method also comprises sensing, using at least one sensor coupled to the second gripper, whether the second gripper engages the stem, node and/or the one or more leaves of the plant.

[00149] In embodiments, enclosing the stem of the plant with the first and second grippers comprises first forming a first enclosure space with the first gripper and subsequently forming a second enclosure space with the second gripper. [00150] In embodiments, the method also comprises driving the first and second grippers away relatively from each other in a direction parallel to the stem after forming of the second enclosure space with the second gripper.

[00151] According to a further aspect of the invention, a grafting method is provided that includes any of the steps for holding and engaging the plant-stem-to-be-grafted as disclosed herein. The method allows cutting a scion with a predetermined length. By holding the to-be- grafted-scion at a predetermined position, e.g. at a position with respect to the node, the stem can be cut with a predetermined length. In embodiments, the grafting method also comprises supplying a rootstock and grafting the scion to a rootstock.

[00152] In embodiments of the holding tool and method, the first and second grippers are relatively moved a predetermined distance away from each other to bring the plant-stem-to- be-grafted in a predetermined position. In other embodiments, the distance is determined by sensors and triggered e.g. by determining that the gripper engages a specific plant stem part, such as the node.

[00153] A further aspect of the disclosed invention for overcoming one or more drawbacks of the prior art comprises providing a holding tool for orienting a plant. The holding tool is arranged to hold the plant in a predetermined orientation. In embodiments, the holding tool is arranged to hold the plant stem near the node of the plant. This will allow subsequently cutting that plant stem at a predetermined distance form the first node of the plant, where the first leaves of the plant are formed.

[00154] In embodiments, the holding tool comprises a gripper arranged to form, in an enclosed state, an enclosure space for receiving a stem of the plant therein. The enclosure space is arranged to, in the enclosed state, enclose the stem in an enclosure plane. Here enclosure space refers to a cavity, e.g. formed between two gripping arm, into which the stem of a plant can be received without constraining or squishing the plant stem. The enclosure space is dimensioned to surround the stem. The enclosure space will be 0.1mm, preferably 0.3 mm and more preferably 0.5mm larger in diameter than then diameter of the plant stem. The gripper will also have an opened state, which allows to initially position the gripper around the stem and the opened state allows releasing the stem.

[00155] Further the enclosure space is dimensioned to engage a node of the stem. The dimensions of the enclosure space, are such that the leaves and thus the first node, cannot fall through the enclosure space. The enclosure space is e.g. maximum 2 cm larger in diameter than the stem, preferably less than 1 cm larger, preferably less than 9 mm larger.

[00156] Upon moving the holding tool, using a holding tool drive, along the stem, the gripper, in the enclosed state, will move parallel to and along the along the direction of the stem of the plant. By moving the gripper away from the root of the plant, the gripper will collide and engage the node of the plant. As the enclosure space is dimensioned such the node cannot fall through, further movement of the gripper along the stem is prevented. [00157] In embodiments, the holding tool has a further gripper with a further enclosure space, wherein a first and second gripper are formed by the gripper and the further gripper. In embodiments, the holding tool has first and second enclosure spaces arranged to enclose a stem of a plant therein, wherein the first and second enclosure spaces are generally aligned along a direction parallel to the stem. In embodiments, the holding tool comprises a gripper drive arranged to move the first gripper with respect to the second gripper in the direction parallel to the aligned enclosure spaces. A holding tool with a first and second gripper allows the enclosure space of the gripper that moves along the stem to be larger, reducing the chance of damage to that stem during movement of that gripper along the stem.

[00158] In embodiments, the holding tool is arranged to enclose the stem of the plant with the first gripper and subsequently enclose the stem with the second gripper. In embodiments, the second enclosure space is formed adjacent to the already formed first enclosure space. In embodiments, gripper drive is arranged to move the first and second gripper a predetermined distance apart. In embodiments, the holding tool is arranged to first form the first and second enclosure space and to subsequently move the first and second gripper apart. In embodiments, the second enclosure space is larger than the first enclosure space. In embodiments, the second gripper is arranged to enclose the stem, preferably without gripping the stem. In embodiments, the first or second enclosure space is circular-, triangular-, rectangular-, pentagonal-, hexagonal and/or multigonal in cross section extending in a stem direction. In embodiments, the first gripper is arranged to engage the stem with a higher force than the second gripper.

[00159] In embodiments, the gripper comprises gripping elements, wherein the enclosure space is formed between the first gripping elements of the first gripper In embodiments, the holding tool comprises at least one gripping element drive arranged to move a gripping element of the gripper with respect to other gripping element of the gripper, wherein the enclosure space is formed between the gripping elements moved in the holding state.

[00160] In embodiments, the holding tool further comprises a blade for cutting the stem for grafting. In embodiments, the blade is arranged to cut the stem at a predetermined distance from the gripper, preferably a predetermined distance from the node of the plant.

[00161] In embodiments, the gripper is arranged to step-by-step enclose, one or more degrees of freedom of the stem of plant. In embodiments, the gripper comprises gripping elements and a pushing element, wherein the pushing element is arranged to move such that the enclosure space is reduced or enlarged, preferably in a direction perpendicular to the stem. [00162] In embodiments, a pushing element drive is arranged to move the pushing element towards enclosure space, wherein preferably the enclosure space is formed between gripping elements of the gripper. In embodiments, the pushing element is arranged to move in a plane perpendicular to the alignment of the enclosure spaces. In embodiments, the pushing element comprises a flexible element on a distal end.

[00163] In embodiments, the holding tool comprises a sensor arranged to sense whether the gripper engages the node and/or the one or more leaves of the plant on the stem.

[00164] Further aspects of the holding a plant in a predetermined orientation provide a processing system for scions for grafting. The processing system can comprise a supply unit, such as a conveyor, for feeding plants with stems for providing scions for grafting, and the holding tool for orienting the plant. In embodiments, the supply unit is arranged to supply plants to the holding tool. In embodiments, the holding tool further comprises a blade for cutting the stem to form a scion for grafting. Such a processing system can be part of am fully automatic grafting system. The processing system can perform one or more of the preparation steps before grafting the plant. With a processing system as disclosed, it is possible to mechanically orient the plant in a predetermined orientation. The predetermined orientation is preferably holding and engaging the plant at the first node with leaves of that plant. The free end of the plant, e.g. cut by the blade, extends preferably vertically downward from the gripper, whereas the leaves are vertically upward from the gripper. By holding and engaging the node, the orientation of the plant is known, and that orientation can be used in the preparation for grafting, e.g. for cutting the plant at a predetermined distance from the first node of the plant to form scions of a predetermined length. [00165] In embodiments, the supply unit has plant locations at a predetermined spacing, wherein the holding tool comprises two or more sets of first and second grippers positioned at the corresponding predetermined spacing.

[00166] Further aspects of the invention for holding a plant in a predetermined orientation comprise providing a grafting system with a processing system comprising a supply unit for supplying rootstocks and a grafting tool for grafting scions and rootstocks supplied thereto. [00167] In embodiments, the holding tool is mounted on a robot arm.

[00168] Further aspects of the invention relate to a method for holding and orienting a stem of a plant in a predetermined orientation. The method comprises providing a plant having a stem with a node with one or more leaves. The stem is enclosed within an enclosure space of a gripper. Enclosing the stem will result in the stem extending from two ends from the gripper. The stem is enclosed at a position free of leaves and around the stem close to the roots or a free end of the plant.

[00169] The enclosure space dimensioned to enclose the stem in an enclosure plane. Two degrees of freedom, a first and a second perpendicular direction. A third, preferably vertical, direction is not constrained. The gripper can be moved along the enclosed stem by driving the gripper parallel to a direction of the enclosed stem. The enclosure space allows the gripper to move in a direction parallel to the stem. By moving the gripper away from the root / free end of the plant, the gripper will move and will collide to engage the node of the stem by the gripper. The enclosure space is dimensioned such that the enclosure space can move, almost without friction, along the stem. The enclosure space is oversized with respect to the stems to be enclosed. The enclosure space is limited in its oversize, so that the enclosure space cannot move over the plant with a node. As a result, the node of the plant functions as a stop for the movement of the gripper along the stem.

[00170] This allows positioning the gripper and thereby the holding tool at a predetermined position with respect to that plant, namely close, preferably directly under, the node of the plant. Further the orientation of the plant is determined by the stem extending through the enclosure space. Preferably the enclosure space is a cavity extending in a vertical direction. The roots or a free end of the plant extend downward.

[00171] In embodiments, the method comprises lifting the plant by its node and/or one or more leaves by a predetermined distance. As the node functions as a stop, moving the gripper while already engaging the node, the node and as a result the plant as a whole, will be moved. This can be a lifting move.

[00172] In embodiments, the method comprises cutting the stem of the plant at a predetermined position on the stem. By cutting at a predetermined distance from the node, which according to the method is engaged by the gripper, the cutting results in a stem length of a predetermined length.

[00173] In embodiments, enclosing the stem with the gripper comprises forming an enclosure space with first and second gripping elements of the gripper. In embodiments, forming the enclosure space further comprises moving a pushing element such that the enclosure space is reduced or enlarged, preferably in a direction perpendicular to the stem. [00174] In embodiments, the method comprises sensing, using at least one sensor coupled to the gripper, whether the gripper engages the stem, node and/or the one or more leaves of the plant. In embodiments of the method, the method comprises cutting the stem to form a scion, supplying a rootstock and grafting the scion to the supplied rootstock.

BRIEF DESCRIPTION OF DRAWINGS

[00175] Embodiments will now be described, by way of example only, with reference to the accompanying schematic drawings in which corresponding reference symbols indicate corresponding parts, and in which:

[00176] FIG. 1 shows an example system for preparing and joining plant stem sections;

[00177] FIG. 2 shows a schematic top view of an example system for preparing and joining plant stem sections, in particular the first and second supply units;

[00178] FIG. 3 shows a schematic top view of an example system for preparing and joining plant stem sections, in particular the stem processing unit;

[00179] FIG. 4 shows a schematic top view of an example system for preparing and joining plant stem sections, in particular the output;

[00180] FIG. 5A-E shows an example embodiment of a holding tool for engaging the stem of a plant;

[00181] FIG. 5F shows a schematic front view of an example embodiment of a holding tool 500 for engaging a stem of a plant.

[00182] FIG. 6 shows an example embodiment of a blade tool for simultaneously cutting a pair of plant stems; [00183] FIG. 7A-D shows an example embodiment of a plant processing tool and blade tool; [00184] FIGs. 8A-8F show schematic front- views of stems that are cut by a system for preparing plant stem sections for grafting.

[00185] FIG. 9 shows an example embodiment of a plant processing tool and a grafting tool; [00186] FIG. 10 shows a close-up of an example embodiment of a grafting tool in which the plant processing tool is hidden for visual purposes;

[00187] FIG. 11 shows an example embodiment of a plant processing tool and finished grafted plant stem section; and

[00188] FIG. 12 shows an example embodiment of a holding tool for engaging a stem of a plant and a method of using such a tool.

DESCRIPTION OF EMBODIMENTS

[00189] Hereinafter, certain embodiments will be described in further detail. It should be appreciated, however, that these embodiments may not be construed as limiting the scope of protection for the present disclosure. The application will provide several embodiments and embodiments will be described with several features. Any of the embodiments and any of the features can be combined, unless explicitly indicated that combining is not possible. Any of the disclosed embodiments and any combination of features disclosed herein can be the subject of a claim and/or of a continuation or divisional application.

[00190] Embodiments of the invention provide a system for, at least partially, automating the preparation and joining of plant stems, also known as grafting. Typically, the bottom part (rootstock) of a plant is joined to the top part (scion) of a different plant using a clip (also known as a grafting element). Before this is done, the stems of the rootstock and the scion need to be prepared. This preparation step can include the cutting of the stems to create contact surfaces that are to be grafted and/or the alignment of the contact surfaces such that a grafting element may be optimally placed.

[00191] In this application, plant-stems-to-be-grafted can refer to complete plants, or to partial plants such as rootstocks, or to separated plant stems, such as scions and/or to plant tissue. Those complete plants, partial plants or plant stems or plant tissue are subsequently used in grafting a grafted plant in the grafting system 100.

[00192] FIG. 1 shows an embodiment of a grafting system 100 for preparing and joining plant stem sections. Grafting system 100 is modular. Grafting system 100 can comprise as modules any combination of first and second supply units 101 and 102, stem processing unit 103, and output unit 104.

[00193] Any of the described modules/units may be customized, interchanged, omitted, and/or swapped. Modules/units can be mostly sealed off from the outside environment. The module housings can have openings for connecting to neighbouring units. Each module can provide a specific functionality to system 100. Plant material and/or other objects may travel between individual units/modules. Units described herein may comprise transparent windows which allow operators to have an unobstructed view of the system and the process.

[00194] Modules/Units described herein can be interconnected. Each of the units of system 100 (such as), may be arranged in a single straight formation, but may also comprise turns, for instance be arranged in an L-shape (top view). System 100 does not necessarily have to be made up of different units or housings but may also comprise a single unit or housing with different sub-units inside.

[00195] Any of the modules may comprise a housing for partly and/or hermetically sealing the inside of that module from the outside environment.

[00196] Grafting system 100 comprises first and second supply units 101 and 102 for providing plants and/or plant stems for grafting. The first and second supply units 101,102 can provide a stem of a rootstock and a scion respectively to further modules in grafting system 100.

[00197] In the embodiment of FIG. 1, first and second supply units 101 and 102 have first and second inputs 105 and 106 respectively. First and second inputs 105 and 106 may comprise a surface and/or conveyor belt on which plant-stems-to-be-grafted or trays of plant- stems-to-be-grafted may be placed. Plant-stems-to-be-grafted may be picked up automatically from first and second inputs 105,106 and can be positioned, within first and second supply units 101 and 102, on to a further supply, such as a conveyor belt or chain with holders.

[00198] In embodiments, picking-up can comprise holding or enclosing or grasping the plant-stems-to-be-grafted from first and second inputs 105 and 106 by one or more robot arms or other type of manipulators. Said robot arms may either be located inside first and second supply units 101 and 102 or outside system 100. Alternatively, plant material may also be manually placed inside first and second supply units 101 and 102.

[00199] In embodiments, plant-stems-to-be-grafted can be provided in plant pots or containers or with roots in substrate. The pots, containers and substrate can be lifted, grasped and manipulated to position the plant-stems-to-be-grafted onto a supply to the further downstream units/modules of grafting system 100.

[00200] First supply unit 101 may be configured to receive and subsequently supply a stem of a rootstock to the system 100. Second supply unit 102 may be configured to receive and subsequently supply a stem of a scion to the system 100. FIG. 2 will provide a more detailed overview of first and second supply units 101 and 102, shown in a top view.

[00201] Once plant-stems-to-be-grafted have been loaded into first and second supply units 101 and 102, those loaded plant-stems-to-be-grafted may be transported downstream to stem processing unit 103 by a transporter, such as a conveyor.

[00202] In embodiments, the conveyor or rail onto which plant-stems-to-be-grafted are loaded extends from one unit/module of grafting system 100 into a further unit/module. In embodiments, at least one conveyor, preferably a conveyor or rail for supporting rootstocks, extends from the first supply unit 101 through the stem processing unit 103 and preferably into the output unit 104.

[00203] In embodiments, the transporter of the supply units 101,102 comprises separate locations for supporting the individual plant stems. The support locations can preferably support containers/pots/substrate of those plant stems. Preferably separate support locations, separated by predefined distance are provided. This allows feeding any of the downstream module with plant-stems-to-be-grafted separated by a predefined spacing. The transporter for loaded scions or rootstocks can support the scions/rootstocks at predetermined spacings. In embodiments, the scions/rootstocks are loaded onto the transporter at predetermined spacings.

[00204] Stem processing unit 103 may comprise a number of individual tools or units that may operate independently or collaborate with other tools or individual units in stem processing unit 103. The goal of stem processing unit 103 is to take plant-stems-to-be-grafted (such as the stems of a rootstock and a scion), join them by means of a graft element, and provide the pair of scion and rootstock or joined plant material to output unit 104. FIG. 3 will provide a more detailed overview of stem processing unit 103, shown in a top view.

[00205] In embodiments, the stem processing unit 103 can comprise multiple modules/units, preferably multiple joined units.

[00206] Once a scion and rootstock are joined, the joined plants are moved and/or provided to output unit 104. Output unit 104 is arranged to output plant material through output 107. Output 107 may comprise a surface, tray, and/or conveyor belt on which joined plant material may be provided. After entering output unit 104, joined plant material may either automatically be moved to output 107 using a conveyor belt, or be grasped from inside output unit 104 and placed on output 107 by one or more robot arms. Such robot arms may either be located inside output unit 104 or outside system 100 partly/entirely.

[00207] Alternatively, plant material may also be manually taken from the inside of output unit 104. FIG. 4 will provide a more detailed overview of output unit 104, shown in a top view.

[00208] Now referring to FIG. 2, which shows a schematic top view of an example system 200 for preparing and joining plant stem sections. The first and second supply units 201 and 202 are provided in partially cross-sectional view. In grafting system 200, first and second supply units 201 and 202 are arranged to provide a plant stem of a rootstock and a scion respectively to downstream modules of the grafting system 200.

[00209] The rootstock (denoted in FIGs. 2-4 by a +-symbol) and/or the scion (denoted in FIGs. 2-5 by an o-symbol) are provided to grafting system 200 by placement on first and second inputs 203 and 204 respectively. Rootstocks 209 and/or scions 210 are provided on first and second inputs 203 and 204 respectively. Supply units 201,201 comprise a grasper on a robot arm 211,212 for automatically/robotically move the rootstocks and scions into first and second supply modules 201 and 202, respectively.

[00210] At least in relation to FIG.2, rootstock 209 refers to a complete plant, possible including soil, substrate, pot, container or to a, partially, prepared rootstock that is to be grafted as rootstock. At least in relation to FIG.2, scion 210 refers to a complete plant, possible including soil, substrate, pot, container or to a, partially, prepared scion that is to be grafted as scion.

[00211] In embodiments, the supplied rootstock 209 and/or scion 210 each comprise a full plant held in a container filled with soil. Further operations performed by grafting system 200 ensure that only the parts of these plants used for grafting are maintained. For instance, given that only the rootstock 209 of plant will be used for grafting, the top part of that plant is removed during the process. Alternatively, individual rootstocks 209 may be placed on first input 203 with the scion already cut off. Similarly, scions 210 of a plant can be supplied for grafting. [00212] Plant-stems-to-be-grafted can be provided individually, with or without container, with or without soil, or can be provided in a tray. In some embodiments, the plant-stems-to- be-grafted are provided on a conveyor, in such a manner that transferring or robot loading is not required and can be loaded and transported continuously onto a subsequent transporter for supply to downstream modules of system 200.

[00213] First and second inputs 203 and 204 can comprise a presentation surface and/or conveyor belt. After placement on that presentation surface or conveyor belt, rootstocks 209 and scions 210 may either automatically move inside first and second supply units 101 and 102 using a conveyor belt or be grasped from first and second inputs 203 and 204 by one or more robot arms 211 and/or 212 to be on a subsequent conveyor 205, 207 of first and second supply units 201 and 202.

[00214] Robot arms 211 and/or 212 are an example of means for loading plant-stems-to-be- grafted onto a transporter for subsequent grafting. The robot arms 211,212 may be arranged to transfer rootstock-plants 209 and scion plants 210 from a crate placed on first and second inputs 203 and 204 to the inside of system 200. Robot arms 211 and/or 212 may comprise at least 2-DOF and are configured to grasp rootstock-plant 209 and/or scion-plant 210 near its container or directly on their stems.

[00215] Rootstock 209 and/or scion 210 may be manually or mechanically or automatically deposited on first and second inputs 203 and 204 at a random position and orientation. The location and orientation of rootstock-plant 209, scion-plant 210, their containers, and/or their stems may be identified by one or more sensors capable of identifying plants or objects, such as a camera, LIDAR, distance sensor, and/or IR-sensor. System 200 may further comprise a memory for storing a number of instructions for identifying and holding rootstock-plant 209, scion-plant 210, their containers, and/or their stems. System 200 may further comprise a processor for executing said instructions, machine learning algorithms, and/or computer vision algorithms for detecting rootstock-plant 209, scion-plant 210, their containers, and/or their stems.

[00216] First and second supply units 201 and 202 may further comprise rootstock-track 205 and scion-track 206 respectively as transporters onto which plant-stems-to-be-grafted are loaded for downstream transport. Rootstock-track 205 and scion-track 206 are respectively configured to receive one or more rootstocks 209 and/or scions 210. After receiving rootstocks 209 and/or scions 210, rootstock-track 205 and scion-track 206 are further respectively configured to transport loaded rootstock-plant 207 and/or loaded scion-plant 208.

[00217] Rootstock-track 205 and scion-track 206 may comprise a track or rail or conveyor with a plurality of holders, such as cups, for receiving individual plant material or plant containers. In embodiments, the holders are arranged to hold containers with soil with plant. Each of the holders provided on rootstock-track 205 and scion-track 206 may be arranged or configured to grasp rootstock 209 and/or scion 210 in a manner such that it stays substantially fixed to rootstock-track 205 and/or scion-track 206 while being transported to and from different units.

[00218] Holding of rootstock 209 and/or scion 210 by the holders allows providing a spacing between the subsequent rootstock and scion. The holders or plant stem locations on the tracks 205,206 can be separated by a predetermined distance. As a result, in downstream modules of system 200, rootstocks and scions are provided at regular intervals or spacings. In embodiments the spacings can be varied throughout the grafting system 200. During processing of the scions/rootstocks in the system 200, the interval distance can change or may vary.

[00219] In other embodiments, no mechanical predetermined locations are provided on the track/conveyors 205,206. Instead, or additionally, the supply units 201,202 operate to position rootstocks 209 and/or scions 210 at predetermined distance from each other on that conveyor 205,206.

[00220] Rootstock-track 205 and scion-track 206 may be actuated by a driving system comprising a motor and a drive unit for transporting docked rootstock 207 and/or docked scion 208 along the direction of rootstock-track 205 and scion-track 206, preferably to and from different modules, starting from first and second supply units 201 and 202, to stem processing unit 103, and to output unit 104. Docked rootstock-plant 207 and/or docked scionplant 208 may be released from their respective holders by different tools, graspers, and manipulators provided in grafting system 200.

[00221] Rootstock 209 and/or scion 210 are respectively placed inside the holders of rootstock-track 205 and/or scion-track 206 by means of one of robot arms 211 and/or 212. Robot arms 211 and/or 212 preferably fill up each of the row of holders of rootstock-track 205 and/or scion-track 206 and do not leave any holders empty. Rootstock-track 205 and/or scion-track 206 may be repeating, meaning that they each comprise a single connecting rail; when the tracks move in direction 213, a single holder of rootstock-track 205 and/or sciontrack 206 returns to its original position after a single full revolution of the track. As system 200 produces joined (grafted) plants at location 215, empty holders can be provided again at location 214, such that they can receive new rootstock-plant 209 and/or scion-plant 210 that are to be joined. Grafted or joined plant stem sections are denoted by a ©-symbol in FIGs. 2- 5.

[00222] Rootstock-track 205 may be a continuous track that runs through each of the units of system 200. This allows processing of the held plant-stems-to-be-grafted at different locations while maintaining the support. This reduces the number of operations. Scion-track 206 may only run through some of the units of system 200.

[00223] Once rootstock 209 and scion 210 have been moved or placed inside first and second supply units 201 and 202 and placed inside the holders of rootstock-track 205 and/or sciontrack 206, docked rootstock-plant 207 and/or docked scion-plant 208 are transported in direction 213 towards stem processing unit 103, shown in FIG. 1.

[00224] FIG. 3 shows a schematic top view of grafting system 300 for preparing and joining plant stem sections, in particular the stem processing unit 301. Supply units are provided on the left-hand side. Rootstock-plants 307 and scion-plants 308 are docked on rootstock-track 305 and scion-track 306. The plant-stems-to-be-grafted are transported or moved downstream to stem processing unit 301. The stem processing unit 301 comprises a plant processing tool 310, which is configured to align pairs of a scion and a rootstock received from the first and second supply units of system 300. Plant processing tool 310 will be described with reference to FIGs. 5 A-E, which will show an example embodiment.

[00225] The grafting system 300 comprises a stem processing unit 301. The stem processing unit 301 comprises a tool supply system that is arranged to supply to and move away different tools from the plant processing tool 310, preferably to one or more processing locations at the plant processing tool. The tool supply system is arranged to supply the different tools one after another. Before a next tool a supplied, the previous tool is moved away. Some tools are suited to perform one or more processes on the rootstock and/or scions. The tool supply system comprises at least two, preferably any combination, of tools including the transfer tool 311, blade tool 312 and graft tool 313. In embodiments, the tool supply system comprises respective drives to move the tools 311-313 towards processing locations of plant processing tool 310 and away therefrom. In FIG. 3 A blade unit 312 is positioned near plant processing tool 310. Blade unit 312 can be replaced by transfer tool 311 or by graft tool 313. Part of the tool supply system can be a processor and sensors for controlling the respective movements of the tools.

[00226] Providing respective tools to plant processing tool 310 may comprise moving said tool to a processing location at the plant processing tool 310. At the processing location, the tools can provide the respective functionality to the plant material / scions / rootstock that is grasped, engaged, and/or aligned by plant processing tool 310.

[00227] The plant processing tool 310 can have one or more, preferably adjacent, processing locations for holding one or more rootstocks and/or scions. The supplied tool, preferably having a similar number of processing locations, is moved such that at each processing location a process can be performed with the scions and/or rootstocks.

[00228] Moving the tool away or withdrawing the tool may comprise removing a tool from the processing location to make space for other tools to be provided to said position or area. By removing the tool, subsequent processes can be performed at the processing locations of the plant processing tool 310. This in turn allows to automatically perform the delicate and difficult processes with high reliability at acceptable costs.

[00229] The transfer tool 311, blade tool 312, and grafting tool 313 are complex and take up significant space. By providing and removing said tools to and from plant processing tool 310, one after the other enough space is ensured for each tool to perform its functionality. Further, this allows individual tools to span a larger footprint and as a result a more effective set-up or configuration, including the necessary complexity, can be provided.

[00230] Grafting system 300, preferably the tool supply system, may further comprise one or more drive systems, comprising a drive unit and an electromotor. One or more of the respective tools can be mounted on a respective subframe. The drive units can be coupled to each of the respective subframes.

[00231] The grafting system, and preferably operated as one of the tools of the tool supply system, can comprise an anti-blade tool 314. The anti-blade tool 314 can comprise slits for receiving a blade while cutting the stem. The anti-blade tool can provide support from an opposite direction while cutting the stem.

[00232] The grafting system, and preferably the tool supply system, can comprise an antigraft tool 315. The anti-graft tool 315 can comprise a support for supporting the stem, while a graft element is being positioned onto the stem. The anti-graft tool can provide support from an opposite direction while grafting the stem. The anti-graft tool is positioned on an opposite side of the stem while the respective tool is supplied.

[00233] In embodiments, said support may comprise a triangular structure as anti-graft tool, having one triangle corner facing one or more stems to be grafted. Said triangle comer is arranged to engage the stem and push it inside the receiving space of a graft element when said stems are being grafted. In embodiments, said triangular structure may alternatively comprise other structures with an elongated portion arranged to support and engage stems when grafting these stems. In embodiments, said support is made from plastic foam.

[00234] Each of the tools 311-315 can be mounted on individual subframes. In embodiments the blade tool 312 and anti -blade tool 314 with one or more slits are mounted on a shared subframe. In embodiments the grafting tool 313 and anti-grafting tool 315 are mounted on a shared subframe. By sharing a subframe, a single drive or electromotor can be used to supply and remove that subframe with multiple tools to and from the processing locations.

[00235] In preferred embodiments, the blade tool 312 and graft tool 313 are provided on a single cut and graft frame. As a result, when tool supply system withdraws e.g., blade tool 312 from plant processing tool 310, grafting tool 313 may automatically be provided to plant processing tool 310.

[00236] Grafting system 300 is arranged, with first and second supply units, to supply two or more pairs stems of a rootstock and a scion respectively. Both rootstocks 307 and scions 308 may be provided to plant processing tool 310 by actuating the drive coupled rootstock-track 305 and scion-track 306 respectively. Alternatively, system 300 may comprise transfer tool 311, configured to receive two or more stems of the scion 308 from the second input and transfer or provide the scion stems 308 to plant processing tool 310.

[00237] Scions can be formed from supplied plants held in a container. The stem of the supplied plant is cut and the upper part with leaves is processed further. The top-part of the plant, that is the part of the plant not held in soil in a container, forms the scion and can be grasped. The top-part of the plant is formed by a top part of the stem, often with leaves attached to it. The length of the stem section on the scion-side can be defined as the distance between the cut and the node (the location at which the stem meets the first leaf).

[00238] The tools 310, 311, 312, 313 are arranged to process multiple plant stems and/or multiple pairs of plant stems comprising rootstocks and/or scions simultaneously. The transferring, the cutting and the grafting of plant stems is performed for multiple plant stems comprising scions and rootstocks simultaneously. Simultaneous processing allows for greater efficiency, reproducibility, and higher throughput than would be allowed by sequential grafting of individual plant stems.

[00239] The transfer tool 311 is arranged to transfer multiple plant-stem-to-be-grafted to the processing locations. The transfer tool has a row of five grippers. The transfer tool 311 holds the multiple plant-stems-to-be-grafted in an aligned fashion, preferably with aligned stems. The second supply unit provides the multiple stems-to-be-grafted to the transfer tool 311. The transfer tool 311 delivers the multiple plant-stems-to-be-grafted in a second row of aligned stems to the processing tool 310. The processing tool 310 is arranged to hold a first row of aligned stems to be grafted received from the first supply unit. The first and second row of plant stems preferably has aligned stems and forms pairs of scion and rootstock stems-to-be- grafted. Both the scions and rootstocks are pre-cut when held in the first and second row by grippers of the plant processing tool 310. The scions and rootstocks have free ends. This allows positioning those free-ends close to each other.

[00240] The adjacent processing locations in the plant processing tool allows holding plant- stems-to-be-grafted with scions and rootstock stems substantially aligned. The scion and rootstock pairs can be held at adjacent processing locations. The pairs may be processed while aligned, preferably simultaneously processed. An example of simultaneous processing is provided by having a cutting tool 312 of the tool supply system, the cutting tool 312 comprising one or more pairs of blades arranged to cut plant stems substantially aligned along the direction of the plant stems to cut aligned pairs of scion and rootstock stems. Multiple pairs of scions and rootstocks-to be are cut simultaneous, while substantially aligned, which allows for more precise cutting of the stems to provide cut stems with cuts that are better aligned, thus allowing for more precise grafting with decreased chance of air bubbles trapped between the cut stems, thereby increasing the chances of successful grafting. Subsequent to cutting, cutting tool 312 may be removed by the tool supply system and grafting tool 313 may be supplied by the tool supply system.

[00241] FIG. 4 shows a schematic top view of a grafting system 400 for preparing and joining plant stem sections, which includes output unit 401. The first supply units for rootstocks and the second supply unit for supply scions are on the lefthand side of FIG. 4, while the output unit 401 is downstream, on the righthand side. System 400 comprises rootstock-track 402, which carry and transport rootstock plants 404. System 400 comprises a scion-track 403, which carries and transports scion plants 405.

[00242] In embodiments, near a downstream end of the scion track 405, a transfer tool similar to the tool described with reference to FIG.5 grasps, and preferably cuts, the scions. Rootstock track 402 continues and travels towards and by the plant processing tool. At the plant processing tool the scions are received from the transfer tool and a grafting tool will graft the scion to the rootstock creating a grafted plant 406. Grafted plant 406 will continue to travel on track 402 towards the output unit 401. After rootstock plants 404 and scion-plants 405 have been grafted in stem processing unit 301, rootstock-track 402 is arranged to carry and transport grafted stems 406. Using a drive system, rootstock-track 402 is configured to transport grafted stems 406 to output unit 401.

[00243] Output unit 401 comprises an output 408 arranged to transport grafted stems 406 outside of system 400. Output 408 may comprise a surface, tray, and/or conveyor belt on which plant material may be placed. Output unit 401 further comprises robot arm 407 configured to transfer grafted stems 406 to output 408. Robot arm 407 may also be configured to transfer grafted stems 406 directly into a crate.

[00244] A transfer tool is shown in FIG. 5A-E. The transfer tool can be part of the tool supply system for supplying and withdrawing tools to the stem processing tool 310. The transfer tool comprises a holding tool 500 for engaging a stem of a plant. Plants can be grasped from a supply line, such as track 507. The holding tool 500 can be mounted on a robot arm or on a subframe. Holding tool 500 with robot arm or subframe forms the transfer tool that can be moved to and away from processing locations of the stem processing tool 310.

[00245] The transfer tool allows to grasp plant-stems-to-be-grafted. The transfer tool can cut plants so that a scion for grafting is formed. The scion is formed while the plant is grasped or at least held. The scions held by the transfer tool 311 is precut to have a free-end before being provided to the processing locations. Pre-cutting a plant in this manner to form a scion increases the flexibility with which it can be handled, e.g. allowing a scion to be transferred by a transfer tool to a position substantially aligned with the scion and/or rootstock along the direction of the stem of the scion and/or rootstock, which otherwise would not be possible as plant from which a scion is formed would collide with a rootstock. The grasped scion can then be transferred to a stem processing location for further processing, including grafting. [00246] The transfer tool 311 comprises a transfer tool sub-frame on to which five adjacent grippers, as shown in FIG.5a, are mounted. As a result, five to be grafted plant stems can be grasped and transferred to a stem processing location. The transfer tool sub-frame can be mounted onto a robot arm with suitable transfer drive for moving the transfer tool sub-frame from one location to a different location. The transfer drive can be controlled by the tool supply system for supply and removing tools to and from stem processing locations. Transferring plant stems by a transfer tool 311 may comprise transferring multiple plant stems comprising rootstocks and/or scions simultaneously. Processing plant stems at multiple processing locations may comprise processing multiple plant stems simultaneously, allowing for greater efficiency, reproducibility, and higher throughput than would be allowed but sequential processing of individual plant stems.

[00247] As the transfer tool 311 is preferably providing a new scion for grafting, the transfer tool 311 is moved to the stem processing location after removing the grafting tool from the stem processing location.

[00248] In embodiments, a pair of rootstock 307 and scion 308 are to be grafted at processing locations formed by the plant processing tool 310 in the stem processing unit 301. To be grafted scions can be pre-processed by the transfer tool 311 as described in relation to FIG. 5A-E. After supplying the rootstocks and scions to be grafted to the stem processing locations, the rootstocks and scions are connecting by a grafting element. In the embodiments of FIG. 7A-D, five stem processing locations are provided at the plant processing tool 310 for processing five scions and rootstocks simultaneously. The transfer tool 311 with grasper tool 500 having five adjacent processing locations can supply five scions in one transfer action to the plant processing tool.

[00249] An example embodiment of plant processing tool 310 is shown in FIG. 7A-D, generally referred to as plant processing tool 700. A scion 709 with node 710 and leaves 711 has been supplied to the middle stem processing location. For clarity four further scions are held by four other grippers are now shown. In FIG. 7A-7D, a track 704 has plant positions 705 that hold with fingers 706 containers 707 with rootstock stems 708 to be grafted.

[00250] In this embodiment, plant processing tool 700 is configured to align and graft five pairs of rootstocks 708 and scions 709. More or less processing locations are also possible within embodiments of the invention. [00251] In embodiments, the distance between the adjacent processing locations and the distance between the five grippers and the distance between the plant locations on the tracks correspond. This makes transferring straightforward. However, adding drives for increasing or decreasing the distance between adjacent positions can be added to any of the described embodiments and to any of the described tools. Also, although adjacent processing locations, grippers and plant locations are shown in row, preferably a straight line, different configurations are possible, including two dimensions arrays. E.g. four scions can be pre- processed by the transfer tool in a 2 x 2 array and be transferred to a 1x4 row.

[00252] In the illustrated embodiment, the rootstock to be grafted are received from the first supply unit. Rootstock track 305 transports the containers to the respective processing locations. The second supply for scions can comprise the transfer tool 500 of FIG. 5A-E. [00253] In an embodiment, plants are supplied to the transfer tool comprising the grasping tool 500 using a supply unit that could correspond with the second supply unit of FIGs 1-3. The supply unit can be any kind of unit that supplies plants, e.g. plants held in a container. In FIG 5A, containers 509 are provided filled with substrate or soil and contains a plant having a stem 511 and a node 512 at which one or more leaves 513 are formed. In other embodiments a substrate or soil with plant is provided without a container. For convenience, only a single plant is shown in FIGs 5A-E.

[00254] In embodiments, the supply unit is formed by a conveyor or a track. In the illustrated embodiment, containers 509 with plants are provided on a track 507 of the conveyor. The conveyor can comprise a rail with a plurality of chains or tracks 507. A plurality of plant locations 508 may be provided on track 507.

[00255] In the illustrated embodiment, each plant location 508 comprises a plurality of fingers 510 for clutching a container 509. Fingers 510 are formed by flexible elements that are biased inwardly, toward each other and are thereby arranged to grasp objects (i.e. container 509) placed in between the plurality of fingers 510. Container 509 may still be removed from the clutch of fingers 510 when enough pulling force is applied.

[00256] In a different embodiment, each of the plant locations on the rootstock- or sciontrack may instead comprise a cone-shaped carrier arranged to receive plants, preferably rootstock-plants, or the containers 509 in which they are placed.

[00257] FIG. 5A shows an example embodiment of a holding tool 500 for processing a plant, e.g. by enclosing, retaining, grasping, and/or engaging the stem of a plant. Holding tool 500 may be used for engaging and handling a supplied plant. The holding tool 500 may be used as a tool to provide scions in a grafting method. The holding tool 500 can be arranged to grasp the plant stems or scions and offer the scions for further handling in a grafting method. [00258] The holding tool 500, preferably part of the transfer tool, comprises a first gripper 501, 502 and a second gripper 505, 506. which are arranged to form a first and second enclosure space respectively. The first and second enclosure spaces arranged to receive a stem of scion 308 therein. The holding tool further comprises a gripper drive to move the first and second grippers with respect to each other in the direction parallel to the stem. [00259] At a predetermined distance from the gripper formed by first and second gripping elements 501, 502, a further first gripper is positioned. Two or more first grippers allow holding multiple plants at the same time. Holding tool 500 may be arranged to engage with multiple plants at the same time, such as five plants. In FIG. 5A-E, the holding tool 500 is shown with five (first) grippers.

[00260] The supply unit can have plant locations at predetermined distances from each other. The spacing between the plant locations on the conveyor is generally the same as the spacing between the grippers. This allows supplying e.g. five plants at five predetermined locations with predetermined spacing and holding those five plants with five grippers at similar predetermined spacing. This will allow holding five plants supplied thereto in a single action. [00261] In an alternative embodiment, the grippers of holding tool 500 are dynamically positionable, meaning that the grippers on holding tool 500 may move individually to increase or decrease the distance between the grippers. In this way, holding tool 500 may accommodate irregular spacings between plant material on the conveyor, e.g. when plant locations on the conveyor are left empty.

[00262] In the holding tool 500 shown in FIGs 5A-E, the first gripper is formed by first and second gripping elements 501 and 502. Other embodiments of a first gripper are also possible within the context of this invention.

[00263] First gripping elements 501 and second gripping elements 502 are arranged to enclose a stem 511 of a plant. In embodiments, the first gripper 501,502 will enclose the stem in directions perpendicular to the stem 511 of the plant. In embodiments, the plant will be supplied with the stem upright, along a vertical direction, indicated in FIGI 0 A by arrow 515. [00264] By enclosing the stem 511 of the plant, the stem is constrained by the first gripper, formed here by first and second gripping elements 501 and 502. Enclosing and constraining encompasses limiting the freedom of movement in at least one direction, preferably in at least two perpendicular directions. In embodiments, enclosing and constraining the stem with the first gripper still allows moving the plant in one or two perpendicular directions. The plant/stem 511 can be enclosed and still be able to move with respect to the gripping elements in a direction 515 along the stem and in a direction 516.

[00265] In embodiments, the first gripper is operated from an opened position as shown in FIG 5 A to an enclosure position. The operation can include driving the gripping elements 501, 502 in the horizontal plane 516,517. In embodiments the gripping elements 501,502 are mounted to a frame of the holding tool 500 via a bearing or pivot. This allows pivoting the gripping elements, preferably around a vertical 515 axis. By driving the gripping elements towards each other, the enclosure space of the first gripper is formed between the gripping elements, in which the stem is enclosed. The enclosure space will extend in the vertical direction. The stem enclosed between the gripping elements is aligned with the direction of the enclosure space.

[00266] The ends of the gripping elements 501,502 have a cavity. The cavity can extend in a direction 515. The enclosure space of the first gripper can be formed by the one or two cavities of the gripping elements, the enclosure space being formed to surround the stem. [00267] In this application, the stem enclosure space refers to any space that can contain a part of the stem of the plant and restrains the movement of the stem in at least one direction. [00268] The first and second gripping elements 501, 502 are formed as an elongated member. A proximal end is connected to the frame of the holding tool 500. The gripper element can have a hook on its distal end. The hook surrounds a part of the enclosure space. The hook is arranged to enclose stem 511 in some or all directions perpendicular to stem 511. [00269] In embodiments, the first gripper, for example the first and/or the second gripping elements 501, 502, may be substantially flexible, such that, when first and second gripping elements 501 and 502 enclose or engage a stem with a larger diameter, stem 511 is not damaged by first and second gripping elements 501 and 502. As such, first and second gripping elements 501 and 502 are configured to enclose, not necessarily grip, stem 511. [00270] First and second gripping elements 501 and 502 may be coupled to at least one sensor configured to measure the force that the first gripper exerts on stem 511, when the first gripper is operated to the enclosure state. The sensor can be a strain gauge. The sensor can also measure the diameter of stem 511. In embodiments, the sensor is coupled to a limit switch. These sensors ensure that first and second gripping elements 501 and 502 do not squish stem 511 when enclosing it.

[00271] Besides first and second gripping elements 501 and 502, the first grippers may further comprise pushing element 503. The pushing element 503, together with the first and second gripping elements, form a first gripper. The pushing element, together with the first and second gripping elements are arranged to enclose stem 511 in all directions.

[00272] By operating the first gripper to first enclose, using the gripping elements, and then constrain the stem, using the pushing element, mechanical flexibility is created for holding the stem. The holding tool 500 will be arranged to engage/grasp the stem of a plant. The first gripper that first encloses and then constrains, will allow holding that stem within a certain range from the holding location. The first gripper will for example grasp any stem within a 2mm range. The exact position of the stem that is to be grasped can be determined with less accuracy.

[00273] After or during the operation to enclose stem 511 in the first gripper with first and second gripping elements 501 and 502, pushing element 503 moves towards stem 511. In embodiments, the direction of movement of pushing element 503 is in the horizontal plane, along direction 517A, which is perpendicular to stem 511.

[00274] In embodiments, pushing element 503 resembles a trapping arm. The pushing element 503 may comprise a rod. A proximal end of the pushing element 503 is connected to a drive that is connected to a frame of the holding tool 500. In embodiments, the pushing element 503 or rod or trapping arm is guided within a channel of the first gripper, in an embodiment within a channel formed between the first and second gripping elements 501,

502.

[00275] A flexible element may be provided on the distal end of the rod. The flexible element is arranged for engaging stem 511. Whereas first and second gripping elements 501 and 502 may solely be configured to enclose stem 511 on three sides, pushing element 503 may be configured to enclose stem 511 from a fourth side.

[00276] As a result, first and second gripping elements 501 and 502, and pushing element

503, together, are configured to enclose, and in some embodiments constrain and grasp, stem 511 in all directions.

[00277] The pushing element 503 can be moved, controlled or based on measurements, to enclose the stem without constraining the stem. Preferably the pushing element 503, and as a result the first gripper as a whole, does not constraint the step in the z-direction 515, parallel to stem 511. In an enclosed state, the gripping elements and pushing rod cooperate to form an enclosure space in which the stem is received, said enclosure space allowing the stem to move in a direction parallel to the direction of the stem.

[00278] By enclosing stem from all sides but in enclosed space of predetermined dimensions that are larger than the diameter of the stem, the first gripper protects stem 511 against squishing during enclosing.

[00279] In embodiments, the hooked distal ends of the first and second gripping elements

501 and 502 form a U-shaped track in which stem 511 is enclosed/trapped. Pushing element 503 can move within the U-shaped track, thereby enclosing stem 511 in (all) directions perpendicular to stem 511.

[00280] FIG. 5B shows an example embodiment of a holding tool 500 for engaging the stem of a plant. FIG. 5B shows first and second gripping elements 501 and 502 of the first grippers in an enclosure position, whereas FIG. 5A shows those first and second gripping elements 501,502 in the open position. Stem 511 is surrounded and enclosed in directions perpendicular to stem 511, such as direction 517 and direction 517A.

[00281] By moving the first and second gripping elements 501,502 towards each other, stem 518 is enclosed at least in the 517 direction. Enclosed encompasses any kind of freedom of movement in a direction. The hooks on the distal ends of first and second gripping elements 501, 502 enclose the stem in the direction 517A. First and second gripping elements 501 and

502 may also comprise other geometries capable of enclosing stem 511 in direction 516b. [00282] FIG. 5B shows the first and second gripping elements 501, 502 in the enclosure position forming a U-shaped cavity 520 (in top-view) between the two gripping elements. The pushing element 503 can move in the U-shaped cavity in a direction 516, thereby reducing the size of the cavity 520.

[00283] Once enclosed by gripping elements 501,502, pushing element 503 may be used to enclose stem 511 in direction 516b. The first gripper, here formed by first and second gripping elements 501, 502 and pushing element 503, is arranged to locate, engage, and enclose stem 511 such that stem 511 will be held in a predetermined position, close to position 518 as shown in FIG. 5B.

[00284] By default, stem 511 of the plant is in an unstructured state; the machine or holding tool 500 does not know where stem 511 is located. The first grippers are configured to pre- align and/or bring stem 511 to preconfigured position 518 by first closing first and second gripping elements 501 and 502, thereby bringing stem 511 to a first coordinate of preconfigured position 518. In the configuration and position of first and second gripping elements 501, 502 in FIG. 5B, stem 511 is enclosed in multiple directions (at least direction 517, preferably also direction 516A) perpendicular to stem 511.

[00285] To enclose stem 511 even closer to preconfigured position 518, pushing element 503 is used to push stem 511 toward the closed distal hook-ends of first and second gripping elements 501 and 502.

[00286] Stem 511 is then enclosed by first and second gripping elements 501 and 502, its distal hook-ends, and pushing element 503 in all directions 516,517 perpendicular to stem 511. Stem 511 is brought to, and enclosed in, preconfigured position 508. Stem 511 is now in a structured state, meaning that the machine or holding tool 500 has localized stem 511. [00287] A visual representation of the process of the above paragraphs is shown in FIG.

12A-C. In FIG. 12A-C, the gripper 2000 is shown in isolation. The gripper 2000 can be connected to the frame of the holding tool 500. The connection can comprise a guide for guiding the gripper in predefined tracks to perform predefined movements. In embodiments, drives are coupled to the gripper for moving the gripper 2000.

[00288] FIG. 12A shows a top view of first gripper 2000, comprising first gripping element 2001 and second gripping element 2002, which is arranged to form a (first) enclosure space 2006. The first enclosure space 2006 arranged to enclose a stem 2004 of a plant.

[00289] In the illustrated embodiment, the gripping elements 2001 and 2002 can move such that their distance ends can move towards each other illustrated by arrows 2015,2016. In embodiments one or two gripping elements are mounted moveable to the frame. A pivoting movement can be preferred. By moving the distal ends together an enclosure space 2006 is formed, which surrounds the stem 2004.

[00290] A pushing element or ram 2003 is arranged to move such that the enclosure space 2006 is reduced or enlarged, preferably in a direction perpendicular to the stem 2004, which will extend in and of the paper according to FIGs 12.

[00291] The gripper 2000 is arranged to bring stem 2004 to a preconfigured location 2005. By first enclosing the stem 2004 with first and second gripping elements 2001 and 2002, the stem 2004 is brought to a location 2005 along an axis 2005B. The stem is confined in the direction 2005 A. As shown in FIG. 12 A, the stem, despite being transported by a track with set locations to a predetermined location, is not at the preferred location 2005, but is off set in both direction 2005A and 2005B. This is a result of the fact that the stems grow under the influence of external conditions. The stem is not perfectly linear.

[00292] FIG. 12B shows gripper 2000 in a state wherein the first and second gripping elements 2001, 2002 are moved towards each other. The gripping elements 2001,2002 have formed a (first) enclosure space 2006 around the preconfigured location 2005, thereby enclosing stem 2004. After being confined in the direction 2005A by the first and second gripping elements 2001 and 2002, the stem is not yet at location 2005 as a deviation along direction 2005B is still possible.

[00293] The pushing element 2003 can be moved in direction 2014. This will push stem 2004 to the preconfigured location 2005 along an axis 2005B as shown in FIG. 12C. Pushing element can have a flexible tip for soft engagement of the stem 2004. Pushing element 2003 can be coupled to a force meter. When the force meter measures a predetermined force, the forward movement along 2014 is stopped to prevent squishing of the stem 2004 by pushing arm 2003.

[00294] The preconfigured location is a location at a certain position with respect to the frame of the grasper tool 500 or transfer tool. In case of multiple adjacent grippers 2000, multiple adjacent preconfigured locations are provided for one grasper tool 500. The adjacent preconfigured locations can be separated by a separation distance. The separation distance can correspond with distances between holding locations on a supply track and/or to distance between respective processing locations in the plant stem processing unit 310.

[00295] FIG. 12C shows gripper 2000 in a state wherein the first and second gripping elements 2001, 2002 are closed and the (first) enclosure space 2006 is further reduced by pushing element 2003, thereby bringing stem 2004 to the preconfigured location 2005 along an axis 2005A and axis 2005B.

[00296] Embodiments of the invention are presented in relation to grafting, in particular the handling of scion-material, but may also be used for other applications. In a grafting method, plant stem sections are provided. The bottom part (rootstock) of a plant is grafted to the top part (scion) of a different plant. Grafting can involve the use of a clip (also known as a grafting element). Stems of the rootstock and the scion are prepared by processing the supplied plant-stems-to-be-grafted. Processing can comprise pre-cutting supplied plant stems. Processing can include the holding, enclosing and/or grasping of a stem at a specific location on the stem, but may also comprise localizing the node of the plant, lifting it, and cutting the stem at a specific distance from the node. Processing can further comprise cutting and grafting.

[00297] With grafting, it is beneficial that the stem of each scion-plant 308 has a specific length from the node of the plant at which one or more leaves are formed. Regardless of the shape or size, it is preferred that each grafted plant has a constant stem length within a single batch. Cutting at a predetermined distance from the node results in more homogeneous batches with similar growth patterns. This can also lower the chance of plant-failures after grafting. It is desired that grafted plants within a single batch share close physical resemblance. It is desired that grafted plants, within a single batch, have a common stem section length on the rootstock-side 307 and have a common stem section length of stem section on the scion-side 308.

[00298] Thus, it is desired to cut at a set distance from the node. This cutting step is performed generally identically for each plant-stem-to-be-grafted, regardless of its shape or size. Cutting at a predetermined distance from the node results in more uniformity within batches and similar growth patterns. It can also lower the chance of plant-failures after grafting. It is an object of the invention to provide a robust, reproducibly, and/or accessible solution for this application. It is desired that grafted plants within a single batch share close physical resemblance. It is desired that grafted plants, within a single batch, have a common stem section length on the rootstock-side and have a common stem section length of stem section on the scion-side.

[00299] A rootstock-plant can be formed from a plant by cutting its stem. The rootstock can be held in a small container or plant pot filled with soil. The stem of the plant sticks out from the soil, optionally held in the container. Containers or plant plugs with a rootstock sticking out are relatively easy to handle and manipulate by a machine. The length of the stem section on the rootstock- si de can be defined as the distance between the soil and the cut. In an embodiment, the system described herein may comprise a cutting unit for cutting the stem of the rootstock-plant, thereby removing the leaf-end, which is positioned at a certain height, thereby resulting in a rootstock of a predetermined length.

[00300] Scions can be formed from supplied plants held in a container. The stem of the supplied plant is cut. The top part of the plant, that is the part of the plant not held in soil in a container, forms the scion and can be grasped. The top-part of the plant is formed by a top part of the stem, often with leaves attached to it. The length of the stem section on the scionside can be defined as the distance between the cut and the node (the location at which the stem meets the first leaf). In embodiments, the current invention aims to improve keeping the scion length generally constant.

[00301] In embodiments of the disclosed holding tool 500, holding tool 500 localizes a node 512 of stem 511. The localization can comprise sensing or identification but is preferably mechanically. Localization of the node allows cutting stem 511 at a location that is persistent with other cuts within the batch of plants that are prepared by holding tool 500. A goal is to maintain a constant length between node 512 and the cut on stem 511 within the batch.

[00302] Holding tool 500 may be arranged to enclose the stem of the plant with the first gripper and subsequently with the second gripper. The first gripper comprises gripping elements 501,502 in FIG. 5A and a pushing element 503 as shown in FIG. 5B. FIGs 5A-5E show five adjacent first grippers.

[00303] As shown in FIG. 5A and 5B, holding tool 500 further comprises a second set of grippers formed by first and second enclosers or gripping elements 505 and 506. First and second enclosers 505, 506 are arranged to enclose and/or engage the same stem 511, enclosed and/or engaged by the first set of gripping elements 501,502, additional to the enclosure by the first grippers.

[00304] In the shown embodiment, the first and second enclosers 505, 506 are formed by two elongated members. The elongated members can be connected to the frame of holding tool 500 and to respective drives 551 for moving the enclosers 505,506. In embodiments, encloser 506 is pivotably connected to the frame around axis 552. First and second enclosers 505, 506 may comprise respective cavities 523,524. The cavities extend in the vertical direction 515. The cavities 523,524 are arranged to receive and enclose stem 511.

[00305] In embodiments, the second gripper drive 551 allows moving the enclosers 505, 506 towards and away from each other, bringing the cavities 523,524 together. Enclosers can be mounted in frame 550 via a bearing 552 that allows pivoting around a vertical 515 axis. Driving the enclosure arms brings the cavities together.

[00306] After closing of the first grippers shown in FIG. 5B, the second gripper with enclosers 505,506 can be closed as shown in FIG. 5C. Whereas the first grippers are arranged to engage and enclose the stem of the plant while allowing the stem’s location to be somewhat variable, the closed first grippers result in limiting the possible positions of the stem to locations close to the enclosure of the first gripper.

[00307] The first gripper and the second gripper are arranged to enclose, engage, constrain, possibly grasp, the stem in two steps. In a first step, the stem 511 is enclosed from within a broader range of possible positions, to a more limited preconfigured position 518. It is noted that enclosing in the first step can be at a predetermined height from the soil 509, but [00308] In a second step, after enclosing the stem in the preconfigured position 518, a second gripper with enclosures 505,506 can be driven to further enclose, engage, constrain, and possibly grasp that stem. In embodiments, the second gripper can be driven to an enclosure state in which an enclosure space of the second gripper surrounds the stem. The second gripper is thus arranged to enclose a stem at a more defined location than the first gripper, which can operate with a position of a stem within a wider range.

[00309] By moving the enclosers 505,506 towards each other, the cavities 523,524 of first and second enclosers 505 and 506 form a circular-, triangular-, rectangular-, pentagonal-, and/or hexagonal- shaped enclosure space which is arranged to engage and/or enclose stem 511.

[00310] Said enclosure spaces are arranged to constrain movement of stem 511 in all directions perpendicular to stem 511 (directions 516A, 516B, and 517), while allowing movement of stem 511 in directions parallel to stem 511 (direction 515). The enclosure space obtained by first and second enclosers 505 and 506 being in a closed position aligns with preconfigured position 518 and with the enclosure space 518.

[00311] Once first and second gripping elements 501,502 and first and second enclosers 505,506 are both in a closed position, the same stem 511 is now enclosed by two different sets of grippers and constrained in all directions perpendicular to stem 511, while maintaining (some) freedom of movement in directions parallel to stem 511. Stem 511 may either be fully unconstrained in direction 515 or be somewhat constrained in direction 515, e.g. only requiring very little force in direction 515 to be released from the enclosure).

[00312] First and second grippers are further arranged to move in a direction 515 relatively away from each other. Direction 515 is parallel with stem 511. FIG. 5D differs from FIG. 5C in that the first and second grippers are moved away from each other.

[00313] By moving the second gripper away from the first gripper, towards the node of scion 308, and engaging the node and/or leaves of scion 308, scion 308 may be lifted to a predetermined height. After lifting, the stem of scion-plant 308 may be cut. After cutting, only the top part (stem + leaves) of scion-plant 308 remains gripped by transfer tool 500. These operations may be performed prior, during, and after scion-plant 308 has been transferred or provided to plant processing tool 310.

[00314] In embodiments, the invention provides for a holding tool that is arranged to localize the stem 511 within a predetermined range and to localize node 512. In embodiments, the holding tool 500 comprises a lifting apparatus 514 or gripper drive. Lifting apparatus connects the main frame of holding tool 500 to the subframe 522. The second grippers, formed by enclosers 505, 506 are mounted on subframe 522, while the first grippers are mounted on the main frame. Lifting apparatus 514 can move the set of second grippers with respect to the first grippers by moving the sub-frame 522.

[00315] Lifting apparatus comprises a gripper drive that is arranged to move, shift, and/or lift the second grippers, here formed by first and second enclosers 505 and 506, in a direction parallel to stem 511. The gripper drive, in embodiments part of lifting apparatus 514, may comprise a drive unit, (electro)motor, control unit, gearbox, and/or belt system.

[00316] In other embodiments, each of the first and second enclosers 505 and 506 of holding tool 500 may be coupled to individual lifting apparatus 514. As a result, each of the first and second enclosers 505 and 506 of holding tool 500 may be moved individually or collectively with respect to the first grippers.

[00317] The width and/or diameter of the enclosure space 519 of first and second enclosers 505 and 506 is larger than the width and/or diameter of stem 511. The width and diameter of the enclosure space 519 permits that the second gripper can be moved in directions parallel to stem 511. While moving the second gripper, the first and second enclosers 505 and 506 maintain a closed position.

[00318] One part of the plant that has a larger width than its stem 511 is the node 512. At node 512, leaves start to form which extend outwardly from stem 511, thereby having a larger width/diameter than stem 511. As such, the enclosure space 519 of first and second enclosers 505 and 506 is unable to move past node 512 when moving in a direction parallel to stem 511.

[00319] Lifting apparatus and first and second enclosers 505 and 506 are configured to move upward (in a direction parallel to stem 511; direction 515) a predetermined distance. As a result of the enclosure space 519 of the second gripper not being able to move past node 512, the enclosure space 519 will engage node 512 and/or one or more leaves 513 of the plant and lift the plant upwardly. In turn, this will result in container 509 or a plant plug being lifted upwardly and (partly) escaping from the clutch of fingers 510.

[00320] Holding tool 500, in particular the second grippers, and preferably the first and second enclosers 505 and 506, is configured to lift an enclosed plant to a predetermined position. In this embodiment, the holding tool determines mechanically the location of the node and moves the node to a predetermined location.

[00321] Upon moving the second grippers, the first and second enclosers 505 and 506 are moved to engage node 512. The plants provided/ supplied to holding tool 500 may vary in height. First enclosing and subsequently moving the enclosure along the stem of the plant, allows moving the enclosure and gripper to engage the node. As the second gripper engages the node, this positions the rest of the stem with respect to that second gripper and thus with respect to the rest of the grasper tool or with respect to another reference.

[00322] Lifting the node allows identifying a constant length with the engaged node as a reference. E.g., by subsequently cutting the stem at 5cm from the second gripper, a stem of 5cm from the first node is obtained.

[00323] In other embodiments, the second gripper and first gripper are arranged to move away from each other, and the motion is stopped, when contact with the node is sensed. The second and first grippers then move individual distances, dependent on the enclosed stem. Subsequently the stem is cut at a predetermined position from the gripper that engages the node of the stem, resulting in a predetermined length of that scion.

[00324] Now referring to FIG. 5E, holding tool 500 may further comprise one or more blade tools 520 arranged to cut stem 511. Preferably, as a result of engaging the node with the second gripper, the stem is cut at a predetermined position from the node.

[00325] It is noted that, although obtaining a predetermined length of the scion is described below in relation to the holding tool 500, in other embodiments, a predetermined length of the scion for grafting can be obtained in subsequent steps, e.g. in the stem processing tool 310.

[00326] Blade tool 520 is provided adjacent, preferably underneath, to first and second gripping elements 501 and 502 of the first gripper. Blade tool 520 may comprise a blade for a cut perpendicular to stem 511. In other embodiments, the cut is at an angle, preferably between 20 and 70 degrees, with respect to the stem direction. Once activated, blade tool 520 pushes the one or more blades in the direction of stem 511, thereby cutting stem 511 at a predetermined position. In embodiments, a slit is provided in a direction behind the stem with respect to the cutting direction.

[00327] In other embodiments, as will be discussed in combination with the plant processing tool 700 or 1100, the blade can be arranged to cut between the first gripper 501,502 and second gripper 505,506. This will similarly result in a stem with a predetermined length from the node 512.

[00328] FIG. 5F shows a schematic front view of an example embodiment of a holding tool 500 for tool for engaging a stem of a plant. Embodiments of the holding tool 500 allow engaging/grasping the stem of the plant at a predetermined position. Embodiments of the holding tool 500 allow engaging/grasping the stem of the plant with respect to a predetermined reference. Embodiments of the holding tool 500 allow providing a constant length 521 between node 512 and the cut on stem 511 within a batch of plants.

[00329] As shown in FIG. 5F, using lifting apparatus 514, first and second enclosers 505 and 506 are moved upward to a predetermined position. Upon moving along the stem of the plant, the enclosure space of the second gripper will collide and engage node 512 and/or leaves 513. By engaging node 512 and/or leaves 513, the plant is lifted upward.

[00330] In a holding tool with a conveyor 507 as support for container, the container 509 holding the plant partly escapes from the clutch of the plurality of fingers 510. Each of the three plants in FIG. 5F has a different height, particularly a different stem-length. By lifting each of the plants by its node 512 and/or leaves 513 to a predetermined position, the stem can be cut at a predetermined location with respect to the engaged / grasped node. Subsequently scions are obtained that are identical. This can reduce the variation in a batch of scions and subsequent grafted plants. A constant length 521 of the stems is obtained.

[00331] Holding tool 500 may comprise multiple individual sets of first and second gripping elements 501 and 502, first and second enclosers 505 and 506, and blade tools 520 for engaging multiple stems of plants simultaneously. FIGs. 5A-E show an example configuration with five individual engaging units provided in a single tool. FIG, 10F shows an example configuration with three first and second grippers provided in a single tool.

[00332] FIGs. 5A-5E show an example embodiment of a method for engaging the stem of a plant. The method comprises providing a plant having a stem 511 with a node 512 with one or more leaves 513. The pl ant- stem-to-be-grafted may further comprise a container 509, preferably filled with soil. The plant may be provided on a track 507 with one or more plant locations 508, each comprising a plurality of fingers 510 arranged to clutch a container 509. Once each of the plants provided, track 507 may be driven using a motor, after which provided plants are de-supplied and new plants are provided. The method may also comprise providing one or more plants.

[00333] The method further comprises enclosing stem 511 of the plant with a first and second gripper, so that the same stem 511 of a single plant is enclosed by the first and second grippers with the positions of the first and second grippers aligned along the direction of the stem 511. Enclosing may comprise enclosing stem 511 in directions perpendicular to stem 511, preferably at least on two sides of stem 511 (directions 517), more preferably further on the front side of stem 511 (directions 516A), and most preferably further on a back side of stem 511 (direction 516B). Enclosing of stem 511 may comprise surrounding, in embodiments constraining the movement of stem 511 in all directions perpendicular to stem 511. Enclosing of stem 511 may comprise stem 511 being fully unconstrained in direction 515 parallel to stem 511 or be somewhat constrained in direction 515, preferably only requiring very little force in direction 515 to be released from the enclosure. As such, enclosing of stem 511 may comprise enclosing and/or clutching stem 511 with little force (< 5N). Enclosing of stem 511 is done is such a way that stem 511 is not damaged and/or squished. Enclosing of stem 511 may comprise clutching and/or squishing stem 511 using flexible and/or soft elements to avoid damage to the stem. Enclosing of stem 511 may be performed by a first set of gripper elements 501 and 502, additionally in combination with pushing element 503 arranged to move such that the enclosure space is reduced or enlarged, preferably in a direction perpendicular to the stem.

[00334] The method further comprises driving the first gripper 501,502and second grippers 505, 506, each gripper element engaging the same stem 511, away from each other in a direction 515 parallel to stem 511. Preferably, the second gripper 505, 506 is moved away from the first gripper with gripping elements 501 and 502 in an upward direction 515 parallel to stem 511. Moving the second gripper with gripping elements 505 and 506 upward may comprise moving the second set of grippers with gripping elements 505 and 506 by a predetermined distance that lies beyond node 512. Moving the second gripper with gripping elements 505 and 506 may comprise using a gripper drive 514 comprising a drive unit, (electro)motor, control unit, gearbox, and/or belt system. [00335] The method may further comprise lifting the plant by its node 512 and/or one or more leaves 513, preferably by a predetermined distance, more preferably by a predetermined distance larger than the distance between the second enclosure space and node 512. Lifting of the plant may comprise engaging node 512 and/or one or more leaves 513 with the second gripper 505 and 506.

[00336] The method may further comprise cutting stem 511 of the plant, preferably at a predetermined position on stem 511, more preferably below the first enclosure space formed by first gripper with gripping elements 501 and 502, most preferably adjacent and below the first enclosure space formed by first gripper with gripping elements 501 and 502. Cutting stem 511 of the plant may comprise cutting the stem perpendicularly to stem 511, preferably using a blade. The method may further comprise performing each of the steps of the method on multiple individual plants simultaneously. Cutting stem 511 may comprise cutting the stems 511 of two or more plants such that the length between the node 512 and the cut is (substantially) identical between the two or more plants.

[00337] Enclosing stem 511 of the plant may comprise forming an enclosure space with a first and second gripping elements 501 and 502 of the first gripper, preferably wherein the first enclosure space is further formed by a pushing element, wherein the pushing element is arranged to move such that the enclosure space is reduced or enlarged, preferably in a direction perpendicular to the stem. Enclosing stem 511 of the plant may further comprise forming an enclosure space with a first and second gripping elements 505 and 506 of the second gripper. The method may further comprise first forming a first enclosure space with the first gripper and subsequently forming a second enclosure space with the second gripper. The method may also comprise driving the first and second grippers away from each other in a direction parallel to the stem happens subsequent to the forming of the second enclosure space with the second gripper.

[00338] The method may further comprise sensing, using at least one sensor coupled to the first gripper and/or second gripper, whether the first and/or second gripper engages stem 511, node 512 and/or the one or more leaves 513 of the plant. The sensor may comprise an LED- photodiode setup, camera and computer vision system, a resistive sensor, and/or a sensor measuring current.

[00339] The method may further comprise lifting, preferably using the second set of grippers 505 and 506, the plant by its node 512 and/or one or more leaves 513 to a predetermined position. Lifting the plant by its node 512 and/or one or more leaves 513 may comprise keeping the first set of grippers with gripping elements 501 and 502 in a closed position. It may further comprise keeping the first set of grippers with gripping elements 501 and 502 stationary. Lifting may further comprise exerting enough force on node 512 and/or leaves 513, such that stem 511 is capable of freely moving in a direction parallel to stem 511.

[00340] FIG. 6 shows an example blade tool 600 for simultaneously cutting multiple plant stems. Specifically, FIG. 6 shows five blade pair subframes 603, each with a pair of blades 604, 605. The five blade pair subframes 603 are mounted on blade tool frame 602. In this example, five blade pairs 604, 605 are arranged to simultaneously cut five pairs of plant stems. For each blade pair subframe 603 connected to blades subframe 602, one pair of plant stems, scion and rootstock, may be simultaneously cut.

[00341] The blade pair subframes 603 are mounted at respective distances. The separation between the subframes corresponds with the distance between processing locations for stems for grafting. In embodiments, the

[00342] Blade tool 600 may be mounted to a robot arm that can be connected to blade tool frame 622. The blade subframe 621 with mounting arm 602 is coupled to the blade tool frame 622 via a guide 620 and is coupled by a blade motor 601. Mounting arm 602 is connected to five blades pair mounting bodies 603. Blades are connected to the blades pair mounting bodies.

[00343] Blade motor 601 is arranged to move blade subframe 621 and the five blades pair mounting bodies 603, preferably forward and backward in a (linear) cutting direction 610. Blade motor 601 may comprise a control unit and an electromotor.

[00344] Blades pair mounting body 603 can receive blade 604 and second blade 605. Blade 604 and second blade 605 may be mounted to blades pair mounting body 603 using nut 608, bolts 609, and/or screws, glued, or be clamped to blades pair mounting body 603. Blade tool 600 may further comprise first and second clamping mechanisms 606 and 607 arranged to respectively clamp blade 604 and second blade 605 to blades pair mounting body 603.

[00345] In embodiments, the blade tool 600 is configured to cut a single stem. Preferably the blade tool is arranged to cut several stems at adjacent processing locations. In more preferred arrangements, the blade tool 600 is arranged to cut two or more pairs of stems of the rootstock and the scion at adjacent processing locations. [00346] In this embodiment, blades 604, 605 are similarly shaped with a generally triangular shape, having one sharp blade edge 611. Blade 604 and second blade 605 are mounted on blades pair mounting body 603 with a non-sharpened end and/or wide ends connected thereto as proximal end.

[00347] Both blade 604 and second blade 605 comprise a blade edge 611, which may extend from close to the proximal end to the distal end. In alternative embodiments, blade edge 611 may also only extend on the distal end of blade 604 and second blade 605. Blades 604, 605 may have also a square shape. Blades 604, 605 may have a straight blade edge or an angled blade edge (as shown in FIG. 6). Blade 604 and second blade 605 may converge towards their distal ends.

[00348] Blades 604, 605 are generally flat and extend in a plane. In the embodiment of FIG.6, blades 604 and second blades 605 are oriented in parallel planes. By having the blade edge 611 of blade 604 parallel to the blade edge 611 of second blade 605, a pair of parallel blade edges is obtained. This allows simultaneous cutting of respective plant stems at the same angle.

[00349] For cutting, the first 604 and second 605 blades are driven in the first direction 610, while the held stems are held, and preferably aligned, in a second direction. Driving in a first direction perpendicular to the second direction, cuts the stems with the first and second blades.

[00350] The planes of the blades 604,605 is a plane that is rotated around the driving or cutting direction 610. The plane of the blades 604,605 is rotated with respect to the direction of the stem to be cut. Cutting the stems results in a cutting surface on the stems that extends in a third direction.

[00351] The orientation of blades 604,605 (third direction) is sidewardly. To cut held stems perpendicular to the direction of the stem, blades 604,605 would extend in a plane perpendicular to the direction of the stem. To cut sidewardly, resulting in a larger surface area of the cut end of the stem, the blades are rotated more than 15 degrees, but preferably less than 75 degrees with respect to plane perpendicular to the stem direction. The 15 - 75 rotation is in a direction around the cutting direction 610.

[00352] The distance between the planes of blades 604,605 is such that a stem extending in second direction, preferably a vertical direction, is received between the blade tips or distal ends of the two blades. By moving the cutting tool with blade tips towards the stems in direction 610, the blade edges 611 will cut progressively through the stem from opposite sides of the stem.

[00353] In the shown embodiment, the blade edges 611 are extend in a parallel plane facing each other. This allows placing a stem between those facing blade edges 611 and cutting that stem on opposite sides. This results in a simultaneous counterforce on those blade edges 611 and thus on the blades pair mounting body 603. As these counterforces are in opposite direction, the net force is reduced. As a result, the deviation of blades pair mounting body when cutting is reduced.

[00354] In embodiments, a scion stem and a rootstock stem are held in a aligned vertical positions. The adjacent processing locations of the blade pairs generally extend in a horizontal direction. By moving the blade subframe 602 in a direction 610, plant stems will be cut under the angle of the blade edge with respect to the vertical. Both scion and rootstock will be cut with at that same angle. Subsequently scion and rootstock can be brought together and grafted straight after cutting without the need for reorientation.

[00355] Blade 604 and second blade 605, in particular blade edges 611, are further facing each other. In this way, normal force exerted on blade 604 and second blade 605 by plant stem sections during cutting are distributed equally over blade subframe 603. This results in a more balanced blade tool capable of making accurate and reproducible cuts.

[00356] Blade 604 and second blade 605 may be angled such that they cut stems at an angle of 30-60 degrees, preferably around 45 degrees, with respect to the plant stem sections. Alternatively, blades pair mounting body 603 may be angled at an angle of 30-60 degrees, preferably around 45 degrees with respect to the plant stem sections.

[00357] Blade 604 and second blade 605 may be mounted on a single blades pair body, such as blades pair mounting body 603, but may also be mounted on individual subframes. These individual subframes may e.g., be connected to blade subframe 602.

[00358] FIG. 7A-D shows a stem processing unit 700 for preparing plant stem sections for grafting, such as rootstock stem 708 and scion stem 709. Stem processing unit 700 comprises top-processor 701 configured to grasp and align the top part of a plant to be grafted and bottom-processor 702 configured to grasp and align the bottom part of a plant to be grafted. Top-processor 701 and bottom-processor 702 may each be coupled to a drive to move topprocessor 701 and bottom-processor 702 with respect to each other, preferably towards and away from each other. [00359] Bottom-parts of plant material that are to be used for grafting, also known as the rootstock, may be supplied on rootstock-track 704. Rootstock-track 704 is configured to receive one or more rootstock-plants. After receiving a rootstock-plant, rootstock-track 704 are further configured to transport a received rootstock-plants between, to, and from different locations (such as stem processing unit 700) by actuating a drive system comprising a motor and a drive unit.

[00360] Rootstock-track 704 may comprise a track or rail with a plurality of plant locations 705 for receiving containers 707 using a plurality of fingers 706 configured to releasably clutch container 707. Container 706 is preferably filled with soil and comprises rootstockstem 708, which protrudes from the soil. Alternatively, rootstock-stem 708 may be provided in soil that is not contained by a container 707, but directly clutched by a plurality of fingers 706.

[00361] The distance between plant locations 705 on track 704 corresponds to the distance between individual plant stem processing locations of plant stem system 700. In the embodiment of FIG. 7 A, five adjacent, separate, plant stem processing locations are provided. The distance between the processing locations corresponds with the distance between plant locations 705 on the track 704. At the stem processing locations, manipulators, such as bottom-gripper 712, on bottom-processor 702 are provided.

[00362] The drive system of rootstock-track 704 is configured to be actuated in a manner such that plant locations 705, preferably rootstock-stem 708, aligns with the processing locations of manipulators, such as bottom-gripper 712, on bottom-processor 702. As a result, the number of individual manipulators on bottom-processor 702 equals the number of rootstock- stems that may be manipulated simultaneously, resulting in increased productivity. [00363] Stem processing unit 700 comprises a bottom gripping unit arranged to hold a stem of a plant, for example rootstock-stem 708. The bottom gripping unit comprises first bottomgripper 712 and second bottom gripper 716. The first and second bottom grippers 712,716 may each comprise two gripping elements for enclosing rootstock- stem 708. Enclosing the stem is preferred to holding or grasping as this results in less force on the stem. In embodiments the enclosing with grippers 712,716 is similar to the holding tool 500 and takes place in steps, wherein in a first step the stem is generally enclosed to a more defined position and subsequently enclosed a second time, followed by increasing the distance between the grippers 712,716. This will be described in the following, although any of the detailed disclosures provided in relation to FIGs 5A-5F can likewise be applied in the stem processing unit 700.

[00364] Enclosing the stem comprises grippers that form an enclosure space that extends in a direction along the stem. Grippers can enclose the stem by approaching the stem from at least two directions, such as the sides of rootstock-stem 708, perpendicular of rootstock-stem 708. [00365] An enclosure space can be formed by the two gripping elements of bottom-gripper 712. The two gripping elements of bottom -gripper 712 comprise a hook on their distal ends for enclosing rootstock- stem 708 near that distal end.

[00366] In embodiments, first bottom-gripper 712 comprises a pusher 713, which is arranged to move such that the enclosure space is reduced or enlarged, preferably in a direction, such as the back-side of rootstock-stem 708, perpendicular to rootstock-stem 708. As a result, first bottom-gripper 712 may be configured to enclose rootstock- stem 708 in some, preferably all, directions perpendicular to rootstock- stem 708.

[00367] By enclosing rootstock- stem 708 in two or more steps, the stem is gently approached and brought to a more and more enclosed, predetermined location with respect to the frame of the stem processing unit. This allows mechanically localizing and enclosing/holding/grasping the stem. As a result, the previously generally known location of rootstock-stem 708, as provided on rootstock-track 704, is brought to a predetermined, more accurately determined location with respect to the bottom-processor 702 or other components of system 700 to manipulate. In doing so, stem processing system 700 is rapidly able to locate the stem of a plant.

[00368] Near the bottom processing locations, stem processing unit 700 comprises second grippers 716. The second gripper 716 is part of the bottom gripping unit. The second gripper is arranged to hold the stem of a plant, for example rootstock- stem 708, at a distance from bottom-gripper or first 716. Second gripper 716 is arranged to form an enclosure space around rootstock- stem 708 using at least one or more movable gripping elements. The enclosure space of the second gripper is, in the embodiment of FIG. 7A above the enclosure space of the first gripper 712.

[00369] Said gripping elements are arranged to receive plant stems within the to be formed enclosure spaces, thereby holding the stems. FIG. 7A show both first gripper 712 and second gripper 716 in an open position. FIG. 7B shows the first gripper 712 and the second gripper 716 is closed position. [00370] In an embodiment, second gripper 716 may be configured to grip rootstock- stem 708 after first gripper 712 has gripped rootstock- stem 708. Suitable gripper element drives are present to move the grippers to open and close the enclosure spaces.

[00371] In embodiments, the supplied scions 709 and rootstocks 708 have free ends that are to be processed for grafting. It is desired for the to-be-grafted surfaces of the rootstock and scion to be angled at 30-60 degrees with respect to the stem direction to increase their surface areas and increase the chance of a successful graft. Further, it is important that the angles of the to-be-grafted surfaces of the rootstock and scion match. In turn, this will lead to the surfaces fitting together well, leaving no air-bubbles, and again increasing the chance of a successful graft.

[00372] Stem processing unit 700 further comprises one or more stem supports 720. The stem supports can be moved in between the first and second grippers 712 and 716. A frontview of stem support 720 provided between the first and second grippers 712 and 716 is shown in the inset figure of FIG. 7A-B.

[00373] The one or more stem supports 720 can be part of the anti-blade tool 314. In embodiments, the stem supports 720 are mounted on a subframe together with the blade tool 600. This allows moving the stem supports and blade tool towards the processing locations together.

[00374] Stem support may comprise an elongated back support surface for supporting an elongated part of the stem of the plant, wherein the elongated support surface extends between the first and the second grippers 712 and 716.

[00375] The support surfaces are provided opposite to blade tool 312. The support surfaces may surround rootstock 307 and scion 308 on opposite sides, such that the blades of blade tool 312 may cut the stems of rootstock 307 and scion 308 and then be received in the one or more slits when cutting.

[00376] Stem support 720 may support and aide in cutting rootstock-stem 708 or scion-stem 709. Similar to a cutting board for cooking, stem support 720 is arranged to provide a solid support surface that a blade used for cutting may engage with to provide a clean cut through the stem. To this end, stem support 720 may further comprise a slit 718 for receiving a blade for cutting the stem of the plant. As a result, the blade used for cutting may protrude through the stem, ensuring that the cut goes all the way through the stem. Further, this removes the need for the blade having to engage stem-support 720, which may lead to the blade and/or stem-support 720 deteriorating over time.

[00377] Slit 718 may extend across the elongated support surface, either spanning its full length or width, or only spanning part of it (forming a slot for receiving a blade). Slit 718 may extend across the elongated support surface of stem support 720 diagonally, preferably at an angle between 30-60 degrees, most preferably 45 degrees. Slit 718 may alternatively extend across the elongated support surface of stem support 720 horizontally.

[00378] Stem support 720 may further be U-shaped in a top-view, comprising a recess for partly receiving the stem of the plant, such as rootstock-plant 708 or scion-plant 709. This may further assure that the stem remains in a vertical straight orientation between first gripper 712 and second gripper 716. In an embodiment, stem support 720 may also be formed by two stem support bodies, wherein preferably the stem support has a stem support bodies 720A,720B drive for moving the stem support bodies with respect to each other, more preferably wherein the slit is formed between the stem support bodies.

[00379] In embodiments, the rootstock-stems are moved to the processing location. Once the processing location is reached, the track is stopped. Subsequently the first gripper moves the first gripping elements towards each other to form an enclosure space around the stem. The pusher 713 can be moved towards the first gripping elements to reduce the size of the first enclosure space. After forming the first enclosure space, the second grippers can be moved to form the second enclosure space. In embodiment the second grippers move away from the first grippers after enclosing. In embodiments, the stem support 720 is moved between the first and second grippers and partially around the stem that extends between the first and second enclosure spaces. For moving (and removing after cutting) the different gripper elements and supports, respective drives are provided. A processing unit can be connected to the drives for controlling them. The drives can be operated as a result of a sensor making a predetermined determination.

[00380] In the embodiment of FIGs 7A-7D, stem processing unit 700 may further comprise top-gripping unit arranged to hold a plant-stem-to-be-grafted, for example scion 709. Scion 709 may be provided to system 700 by means of a scion-track that is similar to rootstocktrack 704. [00381] In preferred embodiments, the scions are provided to stem processing unit 700 by transfer tool 500, such as a robot arm. In the latter case, a gripper of said transfer tool transfers scion-stem 709 to top-gripping unit.

[00382] Top-gripping unit can comprise a third gripper 714 and a fourth gripper 717. The third gripper 714 may comprise two gripping elements for enclosing scion 709 in at least two directions, such as the sides of scion 709, perpendicular to the stem of scion 709. An enclosure space is formed by the two gripping elements of third gripper 714. The two gripping elements of the third gripper 714 may each further comprise a hook on their distal ends for enclosing scion-stem 708 on its front-side.

[00383] Third gripper 714 may further comprise pusher 715, which is arranged to move such that the enclosure space is reduced or enlarged, preferably in a direction, such as the backside of scion 709, perpendicular to the stem of scion 709. As a result, third gripper 714 may be configured to enclose scion-stem 709 in some, preferably all, directions perpendicular to scion-stem 709. By enclosing scion-stem 709, it is brought to a predetermined location. As a result, the previously unknown location of scion-stem 709, is brought to a known location for top-processor 701 or other components of system 700 to manipulate. In doing so, system 700 is rapidly able to locate the stem of a plant.

[00384] Stem processing unit 700 further comprise fourth grippers 717 arranged to hold the stem of a plant, for example scion-stem 709, at a distance from third gripper 714, also known as third gripper 714. Fourth gripper 717 is arranged to form an enclosure space around scionstem 709 using at least one or more gripping elements. Said gripping elements are then arranged to receive plant stems within those enclosure spaces, thereby holding them. FIG. 7A and 2B show both third gripper 714 and fourth gripper 717 in an open- and closed position respectively. In an embodiment, fourth gripper 717 may be configured to grip scion-stem 709 after third gripper 714 has gripped scion-stem 709.

[00385] First gripper 712, second gripper 716, third gripper 714, and fourth gripper 717 are all generally aligned along an axis parallel to the gripped stems of rootstock-plant 708 and scion-plant 709. As a result, once gripped, the stems are in an aligned state, while the cut stem surfaces are generally in parallel planes. In embodiments the first and second grippers can move towards and away from each other. In embodiments the third and fourth grippers can move towards and away from each other. [00386] Stem processing unit 700 further comprises another stem support 720 provided between the third and fourth grippers 714 and 717. The front-view of stem support 720 provided between the first and second grippers 714 and 717 is similar or identical to the stem support between the first and the second grippers 712 and 716 (shown in the inset figure of FIG. 7A-B).

[00387] In embodiments, the stem support comprises stem supports bodies 720A and 720B. Bodies 720A,720B comprise a slit for receiving a blade for cutting stems 708 and 709. Both slits may be oriented parallel with respect to each other. This orientation further matches that of first and second blades 721 and 722, such that they can be seamlessly received in the first and second slits.

[00388] In FIGs. 7C and 7D, the blade tool 724 comprises a blade tool frame 730. In embodiments, the blade tool frame is coupled to the grafting system 300. In embodiments, the coupling can be via blade tool drive and a guide, such as a linear track, can be provided for guiding the predefined movement of the blade tool 724. In other embodiments, the blade tool 724 can be mounted, via the blade tool frame 300 to a robot arm for moving the blade tool to a desired position.

[00389] Blade tool 724 comprises a blade subframe 728 that is coupled via a linear guide track 729 to the blade tool frame 730. A suitable blade electromotor can be provided to operate the respective movement. As will be discussed, the movement provided by the track 729 is in the cutting direction to cut stems with the blades.

[00390] The blade subframe 728 has an arm 723 which allows mounting of several, in this embodiment five, blade pair mounting bodies 726. The blade pair mounting body allows mounting of a pair of blades in parallel planes with blade edges in those parallel planes facing each other to cut a stem between those to blade edges.

[00391] Blades pair mounting body 726 carries blade 721 and further comprises a second blade 722, which allows the simultaneous cutting of a pair of, preferably aligned, stems 708 and 709. The blade motor is arranged to move the mounting arm 723 with blade 721 and second blade 722 into the bottom-slit (first slit) and top-slit (second slit).

[00392] Gripping rootstock-stem 708 at two locations, namely using first gripper 712 and second gripper 716, ensures that rootstock-stem 708 is in a straight orientation between first gripper 712 and second gripper 716. This grip and orientation of rootstock- stem 708 is ideal for cutting, as it is ensured that each cut will be made according to the cutting angle of the blade. The same applies for scion-stem 709, third gripper 714, and fourth gripper 717.

[00393] Grafting system 300, and in some embodiments the blade tool that is supplied and removed with the tool supply unit, may further comprise one or more slits arranged to receive blades of the blade tool 600. The one or more slits in stem support 720 may be provided on the same subframe as blade tool 600. The stem supports 720 with one or more slits may be provided on the subframe that moves blade tool 600. The stem supports 720 form anti-blade tool 314 for support. The stem supports 720 may move together in the direction 517 with the blade tool 600. A suitable horizontal guide can be provided for guiding the subframe that supports the blade tool 600 and stem supports 720. Further drives can be provided for moving the stem supports 720 and blade tool 600 in directions 516A,516B to reach the processing locations at the stem processing unit 700. Alternatively, the one or more slits may be coupled to blade tool 312, such that they are provided and withdrawn to and from plant processing tool 310 at the same time.

[00394] In embodiments, the bottom or top gripping unit can receive the plant-stem-to-be- grafted 709,708 from a transfer tool 200. In embodiments, the transfer tool has five processing locations corresponding with, and with equal separation, the processing locations of the bottom or top gripping units.

[00395] In embodiments, such as the embodiments comprising the transfer tool with holding unit 500, the plant-stems-to-be-grafted are held by the transfer tool in a predetermined position, e.g. with known location of the node. Upon transferring the plant-stem-to-be-grafted to the top or bottom gripping units, that predetermined position or orientation can be passed on. Especially when the top or bottom gripping units engage by grasping and constraining the stem of the transferred plant-stem-to-be-grafted while that stem is still being held by the transfer tool that predetermined position or reference can be passed on to the stem 708,709 held in the bottom or top gripping unit.

[00396] In embodiments, the transfer tool can supply stem(s)-to-be-grafted at the processing location(s) of the stem processing unit 700. The relative position, preferably in the height direction 515, of the transfer tool upon passing over can be known, predetermined or can be measured. E.g. the third gripper can be 5 mm below the second gripper with gripping elements 505,506. Since the node of the plant stem has a predetermined position with respect to the second gripping element 505,506, upon transfer into the bottom or top gripping units that are at a 5mm height difference, the engaged stems 708,709 are moved 5mm with respect to the previous reference obtained with the transfer tool. By e.g. engaging, grasping and/or constraining the transferred stem, the position with respect to the previous reference is maintained and can be used in subsequent processing, e.g. during subsequent cutting and preparation for grafting.

[00397] In FIGs 7A and 7B, the transfer tool has been moved away, after supplying plantstem s-to-be-grafted to the processing locations. By moving the transfer tool away, a next tool can be positioned at the processing locations of the stem processing unit 700. Moving the transfer tool to the processing locations and moving the tool away is controlled by a tool supply system that controls suitable drives.

[00398] Now referring to FIG. 7C, the grafting system comprising stem processing unit 700 further comprises a blade tool similar to the blade tool disclosed in FIG. 1 or in FIG. 6. The blade tool 230 can be mounted on a robot arm via blade motor 724 that is coupled to subframe 723. Blade 721, blade subframes, subframe 723, and blade motor 724 can be similar to the respective elements described in FIG. 6.

[00399] With the transfer tool moved away and plant-stems-to-be-grafted supplied to the processing locations, the blade tool can be moved to the processing locations. The movement can be controlled by the tool supply system. By moving the transfer tool away, the blade tool can be positioned at the processing locations of the stem processing unit 700. Moving the blade tool to the processing locations and, after processing, moving the blade tool away allows supplying a next tool, such as the grafting tool to the processing locations of the stem processing unit 700.

[00400] Five blades subframes each comprise a blade pair 721,722 and are mounted on subframe 723. A blade motor 724 is arranged to move the subframe 723 that holds the five blade subframes, preferably in a direction towards the stem processing unit 700. The five blade subframes align with the five processing locations of the stem processing unit.

[00401] With plant-stems-to-be-grafted 708 in a vertical orientation between first gripper 712 and second gripper 716, lower blade 721 may be used to cut that stem to obtain rootstocks. Blade motor 724 is arranged to drive blade subframe 723 such that blade subframe 723 and its (plurality of) blade(s), such as blades 721 and second blade 722, move towards and cut (the plurality of) rootstock- stem (s) 708 and/or scion-stem(s) 709. [00402] With plant-stems-to-be-grafted 709 in a vertical orientation in top gripping unit with third gripper 717 and fourth gripper 715, upper blade 722 may be used to cut that stem to obtain scions. Blade motor 724 is arranged to drive blade subframe 723 such that blade subframe 723 and its (plurality of) blade(s), such as second blade 722, move towards and cut (the plurality of) rootstock- stem (s) 708 and/or scion-stem(s) 709.

[00403] The example system of FIG. 7C and 7D show a configuration wherein the blade subframe 723 comprises five pairs of blades, arranged to simultaneously cut five pairs of rootstock stems 708 and scion-stems 709. FIG. 7C shows blade subframe 723 in a pre-cutting state, whereas FIG. 7D shows blade subframe 723 in a cut state.

[00404] FIGs. 8A-8F show schematic front-view of stems that are cut by a system for preparing plant stem sections for grafting.

[00405] FIGs. 8A-8C show stems 801,802 that are cut in accordance with systems and method disclosed herein. FIGs. 8D-8F show stems 851,852 cut according to prior common systems for preparing plant stem sections for grafting.

[00406] FIG. 8A shows top-gripping unit comprising third gripper 803 and fourth gripper 804. Top gripping unit encloses or graps scion stem 801. FIG. 8B shows bottom-gripping unit comprising first gripper 806 and second gripper 805. The bottom gripping unit encloses or grips and/or holds rootstock 802. By holding the stems 801,802 at two locations at a distance, the stem is held in a predetermined manner and extends generally straight between the respective grippers 803,804 and 805,806.

[00407] As discussed in relation to FIGs. 5 and FIGs 7, the first and second grippers 806,805 can move with respect to each other, preferably along the stem’s length. The third and fourth grippers 803,804 can move with respect to each other, preferably along the stem’s length. This allows enclosing and/or grasping the stem at a first location and subsequently, while moving the gripper that encloses the stem along that stem away from the other respective gripper.

[00408] Dotted lines in FIGs 8A and 8B show a cutting line along which a blade is moved. The resulting cut surface at the free end of the stem will have a larger surface area, which is beneficial further subsequent grafting. Scion stem 801 and rootstock stem 802 are cut diagonally. The cut scion stem 810 and the cut rootstock stem 811 are subsequently moved together as shown in FIG. 8C, before a grafting element is used to connect to the cut ends. [00409] The direction of the cutting line is set by the orientation of the blades 604,605. In FIGs 8, a blade tool, such as blade 600, can be moved in a cutting direction 610, which in FIGs 8 would be a direction into the paper. Note that the stems 801,802 could be supported at further locations between the grippers. Note that a slit can be formed in those supports to allow the blade to move into the slit during cutting. The planes of the blades for cutting are rotated with respect to the cutting direction 610, resulting in an acute cut of the respective scion or rootstock.

[00410] By using two grippers per plant-stem-to-be-grafted, each of scion stem 801 and rootstock stem 802 positioned and remains in a straight orientation when cutting. When a further support surface 720 is used, in particular a support surface that has a gutter that partially surround the stem between the grippers, the support surface having a slit for receiving the blade, the cut by the blade in the scion and rootstock is guided with high reliability and reproducibility. And as a result, each stem cut has the same angle, regardless of the shape, size and geometry of a plant stem. The cut surfaces of the respective scion and rootstock match as is shown in FIG. 8C. Air pockets between the to-be-grafted-surfaces of the stems are minimized, which leads to a higher grafting yield.

[00411] FIG. 8D shows a scion 851 held by a single gripper 853. FIG. 8E shows a rootstock 852 held by a single gripper 856. As the free ends of scion 851 and rootstock 852 is not held, the resulting cut by respective blades is inaccurate, even when the blades have a parallel orientation. The cut rootstock 855 and the cut scion 854 have cut surfaces with angles that do not match together well. This is a direct result of the fact that scion stem 851 and rootstock stem 852 were not in a straight orientation with respect to the cutting line when they were being cut.

[00412] Individual plant stems, such as scion stem 801 and rootstock stem 802, may differ in shapes, sizes and geometries. As a result of those inherent differences in stems, the free ends of scion 851 and rootstock 852 may be non-straight as a result of their physical shape or as a result of their weight pushing them into a non-straight orientation. When non-matching surfaces are being grafted together, air pockets form between the surfaces and lead to grafts failing.

[00413] After cutting, aligned rootstock- stem 708 and scion-stem 709 may be moved together and joined using a graft element. This movement is enabled by top-processor 701 and bottom-processor 702 each being coupled to a drive system comprising a motor and a drive unit. Preferably, top-processor 701 is arranged to move toward bottom-processor 702 by a predetermined distance, more preferably by a distance such that the distal end (top surface) of rootstock-stem 708 meets the distal end (bottom surface) of scion-stem 709. More preferably, middle-processor 703 is arranged to withdraw or move away from its position inbetween top-processor 701 and bottom-processor 702 to make room for top-processor 701 and bottom-processor 702 moving toward each other.

[00414] Stem processing unit 301 is further arranged to provide and withdraw grafting tool 313 to and from the plant processing tool 310. Grafting tool 313, preferably provided on a subframe, is configured to graft the stems of a root stock and a scion using a graft element. To make room for grafting tool 313, stem processing unit 301 is configured to withdraw blade tool 312 from plant processing tool 310 and provide grafting tool 313 to plant processing tool 310. Grafting tool 313 may further be configured to provide a grafting element, open the grafting element to create a space that is accessible for receiving stem sections of a rootstock and scion, and close the grafting element to trap the stem sections of the rootstock and scion, thereby joining the stem sections and creating a graft. Grafting tool 313 is arranged to operate on rootstock-plant 307 and scion-plant 308 which are kept in alignment by plant processing tool 310. Once joined, the driving system of rootstock-track 305 and/or scion-track 306 may be actuated to move the joined plant sections in direction 309 away from, preferably outside of, stem processing unit 301.

[00415] FIG. 9 shows an example embodiment 900 of a plant processing tool and a grafting tool. In the embodiment shown in FIG. 9, the plant processing tool comprises top-processor 901 and bottom-processor 902. The plant processing tool is configured to process plant stems, such as rootstock- stem 908 and scion-stem 909, received from the first and second supply units. The plant processing tool has moved rootstock- stem 908 and scion-stem 909 together such that a small distance, preferably less than 1 cm, more preferably less than 0.5 mm remains between the cut surfaces of rootstock-stem 908 and scion-stem 909. The plant processing tool also keeps rootstock- stem 908 and scion-stem 909 in an aligned orientation along an axis parallel to rootstock- stem 908 and scion-stem 909. With the cut surfaces of rootstock- stem 908 and scion-stem 909 aligned and close together, a graft element may be placed around both stems to keep them clamped together over time. To this end, (a blade tool removed) and grafting tool 916 is supplied to the stem processing unit or the plant processing tool. Grafting tool 916 is configured to graft pairs of stems of rootstocks 908 and stems of -n- scions 909 with graft elements. Grafting tool 916 may comprise multiple individual grafters 917 (one of which is shown in FIG. 10) arranged to simultaneously graft two or more pairs of rootstock- stem 908 and scion-stem 909. The example embodiment of FIG. 9 shows one grafting tool 916 with five individual grafters 917 connected to a single grafting subframe 918. Grafting subframe 918 is coupled to a grafting drive 919 configured to move grafters 917, grafting tool 916, and/or grafting subframe 918 forward and backward in a direction perpendicular to the stems of rootstock-stem 908 and scion-stem 909.

[00416] FIG. 10 is the same as FIG. 9, but shows another angle, namely one facing the front of grafting tool 916. FIG. 10 shows a close-up of an example embodiment of a grafting tool 1000 in which the plant processing tool is hidden for visual purposes. FIG. 10 shows rootstock- stem 1008 and scion-stem 1009 in an aligned and close-together state. The grippers of the (bottom- and top-) plant processing tool are hidden for visual purposes but are keeping rootstock- stem 1008 and scion-stem 1009 in this aligned and close-together state. FIG. 10 shows a single grafter 1010 of grafting tool 1000, which is configured to to graft pairs of stems of rootstocks 1008 and stems of scions 1009 with a graft element 1001.

[00417] Graft element 1001 is a hollow cylindrical element 1006 that has a side opening extending along the length of the cylindrical element 1006. Graft element 1001 is flexible and arranged to be folded open, creating a receiving space for receiving plant stem sections, preferably simultaneously receiving a section of a rootstock-stem 1008 and a scion-stem 1009. Graft element 1001 further comprises two elongated members 1004, 1005 extending along the length of the cylindrical element 1006. Graft element 1001 is arranged to be folded open when its two elongated members 1004, 1005 are engaged and pinched together. Similarly, as a result of its flexible properties, graft element 1001 is arranged to be closed when the engagement or pinch of its two elongated members 1004, 1005 is released or removed. Other types of graft elements may be used, such as those that need to be opened without the use of elongated members 1004, 1005, plastic bands, ropes, clothe pegs, or other elements configured to clamp a pair of plant stems.

[00418] Grafting tool 1000 or grafter 1010 comprises first and second gripping elements 1002, 1003 arranged to switch graft element 1001 between a closed- and open state. This may comprise engaging one or more elongated elements 1004, 1005 of graft element 1001. First and second gripping elements 1002, 1003 of grafter 1010 may each comprise a cube-like element arranged to engage a majority of a surface of the elongated members 1004, 1005 of graft element 1001. First and second gripping elements 1002, 1003 of grafter 1010 may also comprise a roughened surface arranged to provide additional surface friction when engaging elongated members 1004, 1005. Alternatively, first and second gripping elements 1002, 1003 of grafter 1010 may also comprise a surface with higher surface friction than other surfaces of first and second gripping elements 1002, 1003, arranged to provide additional surface friction when engaging elongated members 1004, 1005. Grafter 1010 is configured to move first and second gripping elements 1002, 1003 toward and away from each other, making a pinching movement, using pinching drive 1007.

[00419] Grafting tool 1000 is configured to bring graft element 1001 to an open state. Grafting tool 1000 is further configured to move opened graft element 1001 in the direction of rootstock- stem 1008 and scion-stem 1009, preferably such that rootstock-stem 1008 and scion-stem 1009 are received inside graft element 1001. Grafting tool 1000 is further configured to bring graft element 1001 to a closed state, thereby clamping rootstock-stem 1008 and scion-stem 1009 together. Grafting tool 1000 is lastly configured to move away from the grafted plant. After rootstock- stem 1008 and scion-stem 1009 are clamped or grafted together, the plant processing tool may further be configured to push rootstock- stem 1008 and scion-stem 1009 together to eliminate any existing air pockets/bubbles present between the cut and grafted surfaces of rootstock- stem 1008 and scion-stem 1009.

[00420] FIG. 11 shows an example embodiment of a plant processing tool 1100 and one finished grafted plant 1103. After graft element 1104 has been brought to a closed state by grafting tool 1000, the graft element 1104 clamps a rootstock- and scion-stem together to form a finished grafted plant 1103. Since the rootstock- and scion-parts of grafted plant stem section 1103 are now clamped, grippers 1108 and 1109 of bottom-processor 1102 and grippers 1105 and 1106 of top-processor are configured to release the grafted plant stem section 1103 after grafting. FIG. 11 shows the grippers and gripping elements in a opened state.

[00421] While FIG. 11 only shows one out of five plants being grafted, plant processing tool 1100 is preferably configured to graft multiple plants simultaneously, such as the five plants shown in FIG. 11.

[00422] Now grafted, the system is configured to transport each of the finished grafted plant stem sections 1103 towards output unit 104. At the output unit 104, the grafter plants are outputted from the system using output 107, which may be a conveyor belt. Finished grafted plant stem section 1103 may be outputted to output 107 by robotically picking grafted plant stem section 1103 from rootstock track 402 or 1110 and placing them on output 107 or 408 using robot arm 407. Alternatively, finished grafted plant stem sections 1103 may be manually picked from rootstock track 1110 or 402 after they have moved away from plant processing tool 1100.

[00423] In the example embodiment of FIG. 11, five plants may be grafted simultaneously at five adjacent processing locations defined by the plant processing tool 1100. Thus, after grafting, rootstock track 1110 is preferably configured to be actuated such that the track moves five “spots” over or plant locations away in the direction of output unit 104. As a result, five new, non-grafted, plant locations arrive at plant processing tool 1100 and the process or method for preparing and joining plant stem sections may be repeated.

[00424] In the following, numbered clauses are provided. The clauses provide further embodiments, but also further features. Any of the features disclosed herein can be combined, unless it is explicitly indicated that such combination is not possible.

[clause 1.] System for grafting plant stems, the system comprising: - a first supply unit for supplying plant-stems-to-be-grafted, - a second supply unit for supplying plant-stems-to-be- grafted, - a stem processing unit (103) configured to process plant-stems-to-be-grafted received from the first and second supply units, - a tool supply system arranged to supply tools to the stem processing unit and arranged to remove tools from the stem processing unit, wherein the tool supply system is arranged to supply one tool after removing the other tool, wherein the tool supply system includes at least the following tools: — a cutting tool configured to cut the plant-stems-to-be-grafted to form one or more pairs of scion and rootstock, — a grafting tool configured to graft one or more pairs of rootstock and scion with one or more graft elements, and - an output unit for outputting one or more grafted pairs of scion and rootstock.

[clause 2.] System according to clause 1 or any system disclosed herein, wherein the stem processing unit is configured to process two or more plant-stems-to-be-grafted at adjacent processing locations; and/or the stem processing unit has two or more adjacent grippers arranged to hold plant-stems-to-be-grafted received from the first or second supply unit; and/or the supplied and removed tools, including the cutting tool and grafting tool, have two or more adjacent processing locations, wherein preferably the processing positions are at a predetermined distance from each other, wherein preferably the first and second supply unit are arranged to supply the plant-stems-to-be-grafted to the processing locations, wherein more preferably individual plant-stems-to-be-grafted are supplied and held at the processing locations, wherein preferably the stem processing unit is configured to process two rows of two or more plant-stems-to-be-grafted at adjacent processing positions, wherein preferably the cutting tool is configured to process at adjacent positions two or more plant-stems-to-be- grafted, and wherein preferably the grafting tool is configured to process at adjacent processing locations two or more pairs of rootstock and scion with graft elements, wherein preferably the first and second supply unit are arranged to supply the plant-stems-to-be- grafted to the processing locations, wherein more preferably individual plant-stems-to-be- grafted are supplied and held at the processing locations.

[clause 3.] System according to clause 1 or 2 or any system disclosed herein, wherein the tool supply system further includes a transfer tool, wherein preferably the second supply unit is arranged to supply plants for scions and is configured to transfer the at least one scion from the second supply unit to the stem processing unit, wherein more preferably the transfer tool is configured to cut at least one, preferably two or more, stems of the supplied plants from the second supply unit, wherein the cut plant forms a scion to be grafted, wherein more preferably the transfer tool is further configured to localize a node on the stem of the scion at which one or more leaves are formed, wherein more preferably the transfer tool is configured to engage the stem of the scion at a predetermined location, preferably a predetermined location with respect to a reference, wherein preferably the reference is the node, wherein the tool supply system and the transfer tool are arranged to transfer the scion to the stem processing unit so that the stem processing unit engages the stem of the scion at a predetermined location, preferably a predetermined location with respect to a reference, wherein preferably the reference is the node.

[clause 4.] System according to any of the previous clauses or any system disclosed herein, wherein the grafting system comprises a frame and wherein preferably first supply unit, second supply output unit, the stem processing unit and the tool supply system are mounted on the frame, and/or wherein the first supply unit, second supply output unit and the stem processing unit are couplable modules, wherein tool supply system preferably comprises one or more drives for moving the cutting tool, grafting tool, and preferably the transfer tool, with respect to the frame, wherein more preferably the one or more drives are arranged to move and remove the cutting tool, grafting tool, and preferably the transfer tool, from one or more processing locations at the stem processing unit, wherein preferably the cutting tool comprises a cutting subframe, wherein preferably the grafting tool comprises a grafting subframe, wherein the subframes are mounted to drives for moving the subframes, wherein more preferably the cutting subframe and the grafting subframe are guided along a track, and preferably are coupled for synchronous movement.

[clause 5.] System according to any of the previous clauses or any system disclosed herein, wherein the first supply units and the output unit have conveyors, preferably conveyors providing separated plant support locations, wherein the first supply unit and the output unit are a single supply and output unit, preferably a single conveyor line, wherein preferably the second supply unit has a conveyor, preferably a conveyor with separate plant support locations, wherein preferably the stem processing unit has adjacent processing locations for stems of plants, wherein the adjacent processing locations align with plant support locations on the first supply unit and/or the output unit, wherein the grafting system comprises a transfer tool for transferring plant-stems-to-be-grafted from the second supply unit to the stem processing unit, wherein the transfer tool has multiple transfer positions that align with plant support locations on the conveyor of the second supply unit and wherein the multiple transfer positions align with processing locations in the stem processing unit, wherein the first supply unit, and preferably the second supply unit, comprises a load unit for loading each plant support locations with plants for scions and rootstocks for grafting.

[clause 6.] System according to any of the previous clauses or any system disclosed herein, wherein the stem processing unit has one or more scion processing locations and one or more rootstock processing locations, wherein preferably the one or more scion processing locations and the one or more rootstock processing locations comprise one or more grippers for gripping the scion and rootstock respectively, wherein more preferably the one or more grippers for gripping the scions and rootstocks are alignable along a direction of the stems, wherein more preferably the one or more grippers for gripping the scions and rootstocks are moveable towards and away from each other, and wherein more preferably the one or more grippers for gripping the scions are moveable in the direction of the stem towards the one or more grippers for gripping the rootstocks, wherein preferably the one or more scion processing locations and one or more rootstock processing locations are aligned, wherein preferably the stem processing unit is arranged to align stems of one or more pairs of scion and rootstock at the processing locations, wherein more preferably the cutting tool comprises one or more pairs of blades at adjacent processing locations, the pair of blades arranged to cut the scion and the rootstock engaged by the stem processing unit, wherein preferably the cutting tool comprises one or more pairs of blades arranged to cut the scion and the rootstock, the pairs of blades being substantially aligned along the direction of the plant stems to form aligned pairs of scion and rootstock stems, wherein preferably the grafting tool comprises one or more graft element applicators at adjacent processing locations, graft element applicators arranged to connect the scion and the rootstock engaged by the stem processing unit.

[clause 7.] System according to any of the preceding clauses or any system disclosed herein, wherein the stem processing unit has one or more stem processing locations, which have one or more grippers for holding the plant stem, wherein the tool supply system is arranged to supply and remove one or more tools to that one or more stem processing locations by supplying and removing the tool in and from two generally opposite direction to the one or more processing locations, wherein preferably the opposite directions are generally perpendicular to a direction of the stem held by the one or more grippers.

[clause 8.] System according to any of the preceding clauses or any system disclosed herein, wherein the tool supply system is arranged to remove one tool, before supplying a next tool, wherein preferably a cutting and grafting subframe is provided and the cutting tool and grafting tool are provided on the cutting and grafting subframe, and a cutting and grafting subframe drive is arranged to supply and remove the cutting tool to the stem processing unit and is arranged to supply and remove the grafting tool to the stem processing unit, wherein preferably the cutting and grafting subframe is guided in a plane generally perpendicular to a direction of the plant stem held by the stem processing unit.

[clause 9.] Method for grafting plant stems, the method comprising: - providing plant- stems-to-be-grafted; - holding the plant-stems-to-be-grafted at two or more adjacent plant stem processing locations, - supplying a cutting tool to the two or more adjacent plant stem processing locations, and cutting the plant-stems-to-be-grafted, - supplying a grafting tool to the two or more adjacent plant stem processing locations, wherein the grafting tool is supplied after removing the cutting tool, and - grafting a pair of cut plant stems.

[clause 10.] Method for grafting plant stems, the method comprising: - providing plant- stems-to-be-grafted, - cutting plants-stems-to-be-grafted to form scions-to-be and rootstocks- to-be, - holding one or more pairs of scion-to-be and rootstock-to-be at one or more plant stem processing locations, - supplying a cutting tool to the one or more plant stem processing locations, and cutting the one or more pairs to form one or more pairs of scion and rootstock, - supplying a grafting tool to the one or more plant stem processing locations, wherein the grafting tool is supplied after removing the cutting tool, and - grafting the one or more pairs of scion and rootstock.

[clause 11.] Method according to clause 9 or 10 or any method disclosed herein, wherein several plant stems are held at adjacent plant stem locations, wherein preferably supplying plant stems comprises supplying several adjacent plant stems, more preferably conveying several adjacent plant stems, wherein preferably several plant stems are held in two rows of adjacent plant stem locations, wherein preferably a first row holds rootstocks and the second row holds scions, wherein more preferably the method comprises aligning stems in the first row with stems in the second row, wherein more preferably the method comprises moving plants stems held in the first row towards plant stems held in the second row, wherein preferably the plant stems are held with the plant stems held in generally aligned positions, wherein preferably providing plant-stems-to-be-grafted comprises supplying several adjacent plant stems, more preferably conveying several adjacent plant stems, wherein preferably the plant-stems-to-be-grafted are cut generally simultaneously in the adjacent plant stem locations, preferably in the two rows of adjacent plant stem locations, wherein more preferably cutting comprises several pairs of blades cutting the stems, wherein the first blade in the pair of blades cuts the plant stem held in first row and the second blade in the pair of blades cuts the plant stem held in the second row, wherein preferably the grafted pair of cut plant stems is formed from a scion from the second row and a rootstock from the first row, and several grafted pairs of cut plant stems are grafted simultaneously in adjacent plant stem locations,

[clause 12.] Method according to clause 9 or 10 or 11 or any method disclosed herein, wherein providing plant-stems-to-be-grafted comprises supplying plant stems, cutting the plant stems and holding the cut plant stems at one or more plant stem processing locations, wherein the cut plant stems preferably form scions for the to be grafted plants, wherein preferably the method further comprises transferring the cut plant stems to the plant stem processing locations, wherein preferably two or more supplied plant stems are cut and transferred to two or more adjacent stem processing locations simultaneously, wherein preferably two or more supplied plant stems are transferred after removing grafting tool, wherein preferably two or more supplied plant stems are transferred before supplying the cutting tool, wherein preferably holding the cut plant stems comprises holding the cut plant stems at a predetermined position, wherein preferably the predetermined position is with respect to a reference, preferably with respect to a node of leaves on the plant stem, wherein preferably transferring the held cut plant stems comprises taking over the held cut plant stems at the plant stem processing locations at a predetermined position, wherein preferably the predetermined position is with respect to a reference, preferably with respect to a node of leaves on the plant stem.

[clause 13.] Method according to any of the clauses 9 - 12 or any method disclosed herein, wherein supplying the grafting tool after removing the cutting tool comprises driving the grafting tool and cutting tool, both mounted on a grafting and cutting subframe, wherein supplying and removing the grafting tool and the cutting tool comprises driving the grafting and cutting tool in a direction generally perpendicular to a direction of the held plant stems at the plant processing location, more preferably comprising driving the grafting and/or cutting tool simultaneously in a first direction generally perpendicular to the plant stem direction and in second, opposite to the first, direction.

[clause 14.] Method according to any of the clauses 9 - 13 or any method disclosed herein, wherein providing plant-stems-to-be-grafted comprises supplying plant stems held in a container, preferably conveying the containers with plant stems, wherein preferably the supplied plant stems held in containers are supplied to be held at the adjacent stem processing locations, wherein preferably the supplied containers are supplied at mutual distances, the mutual distance corresponding to the mutual distance of adjacent stem processing locations, wherein scions are grafted onto the plant stems held in the container and the grafted plant is transported further in the container.

[00425] In the following, numbered clauses are provided. The clauses provide further embodiments, but also further features. Any of the features disclosed herein can be combined, unless it is explicitly indicated that such combination is not possible.

[clause 1.] A holding tool for engaging a stem of a plant, comprising a first gripper and a second gripper, the first and second grippers arranged to form a first and second enclosure space respectively, the first and second enclosure spaces arranged to enclose the stem of the plant therein, wherein the first and second enclosure spaces are generally aligned along a direction parallel to the stem, wherein the holding tool comprises a gripper drive arranged to move the first gripper with respect to the second gripper in the direction parallel to the aligned enclosure spaces.

[clause 2.] The holding tool of clause 1 or any holding tool disclosed herein, wherein the gripper drive is arranged to move the first gripper with respect to the second gripper with the stem enclosed by the first gripper and by the second gripper, in the direction parallel to the aligned enclosure spaces, wherein preferably the holding tool is arranged to enclose the stem of the plant with the first gripper and subsequently enclose the stem of that plant with the second gripper, wherein preferably the second enclosure space is formed adjacent to the already formed first enclosure space, the first and second enclosure spaces preferably aligned with the stem of the held plant, wherein the gripper drive is arranged to move the second gripper from adjacent to the first gripper to a predetermined distance apart from the first gripper.

[clause 3.] The holding tool of any of the previous clauses or any holding tool disclosed herein, wherein the gripper drive is arranged to move the first and second gripper a predetermined distance apart, wherein preferably the holding tool is arranged to first form the first and second enclosure space and to subsequently move the first and second gripper apart, [clause 4.] The holding tool of any of the previous clauses or any holding tool disclosed herein, wherein the second enclosure space is larger than the first enclosure space, wherein preferably the second gripper is arranged to enclose the stem, preferably without gripping the stem, wherein preferably the first or second enclosure space is circular-, triangular-, rectangular-, pentagonal-, hexagonal and/or multigonal in cross section extending in a stem direction, wherein preferably the first gripper is arranged to engage the stem with a higher force than the second gripper,

[clause 5.] The holding tool of any of the previous clauses or any holding tool disclosed herein, wherein the first gripper comprises first gripping elements, wherein the first enclosure space is formed between the first gripping elements of the first gripper, wherein preferably the second gripper comprises second gripping elements, wherein the second enclosure space is formed between the second gripping elements of the second gripper, wherein the holding tool comprises at least one gripping element drive arranged to move a gripping element of the gripper with respect to other gripping element of the gripper, wherein the enclosure space is formed between the gripping elements moved in the holding state. [clause 6.] The holding tool of any of the previous clauses or any holding tool disclosed herein, wherein the holding tool further comprises a blade for cutting the stem for grafting, wherein preferably the blade is arranged to cut the stem at a predetermined distance from the first or second gripper, preferably a predetermined distance from the node of the plant, [clause 7.] The holding tool of any of the previous clauses or any holding tool disclosed herein, wherein the first gripper is arranged to step-by-step enclose, preferably constrain, one or more degrees of freedom of the stem of plant, wherein preferably the first gripper is arranged to constrain the stem of plant in direction perpendicular to the stem and subsequently in a direction parallel to the stem, wherein more preferably the first gripper comprises gripping elements and a pushing element, wherein the pushing element is arranged to move such that the enclosure space is reduced or enlarged, preferably in a direction perpendicular to the stem.

[clause 8.] The holding tool of any of the previous clauses or any holding tool disclosed herein, wherein the first gripper further comprises a pushing element to enclose or engage or constrain the stem in the first enclosure space, wherein preferably a pushing element drive is arranged to move the pushing element towards first enclosure space, wherein preferably the first enclosure space is formed between gripping elements of the first gripper, wherein the pushing element is arranged to move in a plane perpendicular to the alignment of the enclosure spaces, wherein more preferably the pushing element comprises a flexible element on a distal end.

[clause 9.] The holding tool of any of the previous clauses or any holding tool disclosed herein, wherein the holding tool comprises a sensor arranged to sense whether the first or second gripper engage the node and/or the one or more leaves of the plant on the stem, [clause 10.] A processing system for scions for grafting comprising: a supply unit, such as a conveyor, for feeding plants with stems for providing scions for grafting, and the holding tool according to any of the previous clauses or any holding tool disclosed herein, wherein the supply unit is arranged to supply plants to the holding tool, wherein the holding tool further comprises a blade for cutting the stem to form a scion for grafting.

[clause 11.] System according to clause 10 or any system disclosed herein, wherein the supply unit has plant locations at a predetermined spacing, wherein the holding tool comprises two or more sets of first and second grippers positioned at the corresponding predetermined spacing. [clause 12.] Grafting system comprising the processing system according to any of the clauses 10 - 11 or any system disclosed herein, comprising a supply unit for supplying rootstocks and a grafting tool for grafting scions and rootstocks supplied thereto, wherein preferably the holding tool is mounted on a robot arm.

[clause 13.] A method for holding a stem of a plant, comprising: - providing a plant having a stem, preferably with a node with one or more leaves; - enclosing the stem of the plant with first and second grippers; - driving the first and second grippers away from each other in a direction parallel to the stem, preferably while enclosing the stem of the plant.

[clause 14.] The method of clause 13 or any method disclosed herein, further comprising: - driving the first and second grippers away from each other in a direction parallel to the stem while enclosing the stem of the plant with the first and second grippers; and/or - lifting the plant by its node and/or one or more leaves by a predetermined distance; and/or - cutting the stem of the plant at a predetermined position on the stem.

[clause 15.] The method of clause 13 or 14 or any method disclosed herein, - wherein enclosing the stem with the first gripper comprises forming an enclosure space with a first and second gripping elements of the first gripper; and/or - wherein enclosing the stem with the first gripper comprises forming an enclosure space with a first and second gripping elements of the first gripper forming a circular-, triangular-, rectangular-, pentagonal-, and/or hexagonal -enclo sure .

[clause 16.] The method of clause 15 or any method disclosed herein, wherein forming the first or second enclosure space further comprises moving a pushing element such that the enclosure space is reduced or enlarged, preferably moving in a direction perpendicular to the stem.

[clause 17.] The method of any of the clauses 13-15 or any method disclosed herein, further comprising: - sensing, using at least one sensor coupled to the first gripper, whether the first gripper engages the stem, node and/or the one or more leaves of the plant; and/or - sensing, using at least one sensor coupled to the second gripper, whether the second gripper engages the stem, node and/or the one or more leaves of the plant.

[clause 18.] The method according to any of the clauses 13-17 or any method disclosed herein, wherein enclosing the stem of the plant with the first and second grippers comprises first forming a first enclosure space with the first gripper and subsequently forming a second enclosure space with the second gripper. [clause 19.] The method of clause according to clause 18 or any method disclosed herein, wherein the first and second grippers are driven away from each other in a direction parallel to the stem after forming of the second enclosure space with the second gripper.

[clause 20.] A grafting method comprising any of the clauses 13-19 or any method disclosed herein, further comprising cutting the stem to form a scion, supplying a rootstock and grafting the scion to the supplied rootstock.

[clause 21.] A holding tool for orienting a plant, comprising a gripper arranged to form, in an enclosed state, an enclosure space for receiving a stem of the plant therein, wherein the enclosure space is arranged to, in the enclosed state, enclose the stem in an enclosure plane, wherein the enclosure space is dimensioned to surround the stem and is dimensioned to engage a node of the stem, wherein the holding tool comprises a holding tool drive for driving the gripper in the enclosed state in a direction substantially parallel to and along the stem of the plant.

[clause 22.] The holding tool of clause 21 or any holding tool disclosed herein, wherein the holding tool has a further gripper with a further enclosure space, wherein a first and second gripper are formed by the gripper and the further gripper, wherein the holding tool first and second enclosure spaces are arranged to enclose the stem of the plant therein, wherein the first and second enclosure spaces are generally aligned along a direction parallel to the stem, wherein the holding tool comprises a gripper drive arranged to move the first gripper with respect to the second gripper in the direction parallel to the aligned enclosure spaces, wherein the holding tool is arranged to enclose the stem of the plant with the first gripper and subsequently enclose the stem of the plant with the second gripper, wherein preferably the second enclosure space is formed adjacent to the already formed first enclosure space, wherein preferably the gripper drive is arranged to move the first and second gripper a predetermined distance apart, wherein preferably the holding tool is arranged to first form the first and second enclosure space and to subsequently move the first and second gripper apart, wherein the second enclosure space is larger than the first enclosure space, wherein preferably the second gripper is arranged to enclose the stem, preferably without gripping the stem, wherein preferably the first or second enclosure space is circular-, triangular-, rectangular-, pentagonal-, hexagonal and/or multigonal in cross section extending in a stem direction, wherein preferably the first gripper is arranged to engage the stem with a higher force than the second gripper. [clause 23.] The holding tool of clause 21 or 22 or any holding tool disclosed herein, wherein the gripper comprises gripping elements, wherein the enclosure space is formed between the first gripping elements of the first gripper, wherein the holding tool comprises at least one gripping element drive arranged to move a gripping element of the gripper with respect to other gripping element of the gripper, wherein the enclosure space is formed between the gripping elements moved in the holding state.

[clause 24.] The holding tool of any of the clauses 21-23 or any holding tool disclosed herein, wherein the holding tool further comprises a blade for cutting the stem for grafting, wherein preferably the blade is arranged to cut the stem at a predetermined distance from the gripper, preferably a predetermined distance from the node of the plant.

[clause 25.] The holding tool of any of the clauses 21-24 or any holding tool disclosed herein, wherein the gripper is arranged to step-by-step enclose, one or more degrees of freedom of the stem of plant, wherein preferably the gripper comprises gripping elements and a pushing element, wherein the pushing element is arranged to move such that the enclosure space is reduced or enlarged, preferably in a direction perpendicular to the stem, wherein preferably a pushing element drive is arranged to move the pushing element towards enclosure space, wherein preferably the enclosure space is formed between gripping elements of the gripper, wherein the pushing element is arranged to move in a plane perpendicular to the alignment of the enclosure spaces, wherein more preferably the pushing element comprises a flexible element on a distal end.

[clause 26.] The holding tool of any of the previous clauses or any holding tool disclosed herein, wherein the holding tool comprises a sensor arranged to sense whether the gripper engages the node and/or the one or more leaves of the plant on the stem.

[clause 27.] A processing system for scions for grafting comprising: - a supply unit, such as a conveyor, for feeding plants with stems for providing scions for grafting, and - the holding tool according to any of the clauses 21-26 or any holding tool disclosed herein, wherein the supply unit is arranged to supply plants to the holding tool, wherein the holding tool further comprises a blade for cutting the stem to form a scion for grafting.

[clause 28.] System according to clause 27 or any system disclosed herein, wherein the supply unit has plant locations at a predetermined spacing, wherein the holding tool comprises two or more sets of first and second grippers positioned at the corresponding predetermined spacing. [clause 29.] Grafting system comprising the processing system according to clause 27 or 28 or any grafting system disclosed herein, comprising a supply unit for supplying rootstocks and a grafting tool for grafting scions and rootstocks supplied thereto, wherein preferably the holding tool is mounted on a robot arm.

[clause 30.] A method for holding a stem of a plant in a predetermined orientation, comprising: - providing a plant-to-be-grafted having a stem with a node with one or more leaves, - enclosing the stem within an enclosure space of a gripper, the enclosure space dimensioned to enclose the stem in an enclosure plane, and - driving the gripper in a direction parallel to the stem to engage the node of the stem by the gripper.

[clause 31.] The method of clause 30 or any method disclosed herein, further comprising: - lifting the plant by its node and/or one or more leaves by a predetermined distance; and/or - cutting the stem of the plant at a predetermined position on the stem.

[clause 32.] The method of clause 30 or 31 or any method disclosed herein, - wherein enclosing the stem with the gripper comprises forming an enclosure space with first and second gripping elements of the gripper, - wherein forming the enclosure space further comprises moving a pushing element such that the enclosure space is reduced or enlarged, preferably in a direction perpendicular to the stem.

[clause 33.] The method of any of the clauses 30-32 or any method disclosed herein, further comprising: - sensing, using at least one sensor coupled to the gripper, whether the gripper engages the stem, node and/or the one or more leaves of the plant.

[clause 34.] A grafting method comprising any of the clauses 30-33 or any method disclosed herein, further comprising cutting the stem to form a scion, supplying a rootstock and grafting the scion to the supplied rootstock.

Claims

1. A blade tool for simultaneously cutting a pair of plant stems, the blade tool comprising: a blade tool frame (622) and blade subframe (621) coupled to the blade tool frame a blades drive arranged to move the blade subframe with respect to the blade tool frame, one or more blades mounted on the blade subframe with a proximal end, the one or more blades having a blade edge that extends to a distal end, one or more second blades mounted on the blade subframe with a second proximal end, the one or more second blades having a second blade edge that extends to a second distal end, wherein the one or more blades are arranged to cut one stem of the pair of plant stems and the one or more second blades are arranged to cut the other stem of the pair of plant stems, and wherein the blade edges are facing each other.

2. Blade tool according to claim 1, wherein the one or more blades and the one or more second blades are arranged to generally cut the pair of stems simultaneously, wherein preferably the one or more blades and one or more second blades are oriented in parallel planes, wherein preferably a pair of the blade and the second blade have blade edges extending in the parallel planes, wherein preferably the pair of the blade and the second blade have blade edges that are positioned to, in the parallel planes, converge towards each other from the distal end. wherein preferably a distance between the blade edges of the blade and second blade increases towards the distal end, wherein preferably the blade converges towards the blade distal end.

3. Blade tool according to claim 1 or 2, wherein a pair of the blade and second blade are mounted on a blades pair mounting body that is mounted to the blade subframe, wherein blades pair mounting body comprises two mounting surfaces for supporting a flat surface of the blade and the second blade, wherein the two mounting surfaces extend in parallel planes, wherein multiple blades pair mounting bodies are mounted in adjacent positions in a row onto the blade subframe, the multiple blades pair mounting bodies each arranged in similar orientations.

4. Blade tool according to any of the previous claims, wherein blade tool frame (622) is coupled to the blade subframe (621) via a track, preferably a linear track, wherein preferably the drive is arranged to move the blade subframe in a direction towards the distal end of the blade, wherein preferably the track extends in a first direction and the blade edge extends along the first direction, wherein preferably the blade tool frame mountable in a frame of a grafting system, wherein the blade tool frame has mounting units extending in second direction, perpendicular to the drive direction of the blades drive that couples the blade tool frame to the blade subframe, wherein preferably the blade tool frame is coupled via a blade tool drive, such as a robot arm, to the frame of grafting system.

5. System for preparing plant stem sections for grafting, the system comprising:

- a first gripper for holding a stem of a plant,

- a second gripper for holding the stem of the plant, wherein the second gripper is arranged to hold the stem at a distance from the first gripper,

- a blade mounted on a blade subframe with a blade motor for moving the blade between the first and second grippers.

6. System according to claim 5, wherein a stem support is provided between the first and second grippers, wherein preferably the stem support has an elongated back support surface for supporting an elongated part of the stem of the plant, wherein the elongated support surface extends between the first and the second gripper, wherein more preferably the stem support comprises a slit for receiving the blade for cutting the stem of the plant, wherein the slit extends across the elongated support surface.

7. System according to claim 5 or 6, wherein the system comprises a first gripper drive, a second gripper drive, and wherein the system is arranged to drive the first gripper drive to hold the stem with the first gripper, to then drive the second gripper drive to hold the stem with the second gripper, and to subsequently drive the blade motor to cut the stem with the blade, wherein preferably the system comprises a stem support drive, wherein the system is arranged to drive the stem support drive to support the stem with the stem support after driving the second gripper and before cutting, wherein more preferably the system comprises a further gripper drive to move the first and second gripper away, and preferably towards, each other.

8. System according to any of the claims 5 -7, the system further comprises a third gripper and a fourth gripper to hold a stem of a different plant, wherein blade subframe comprise a second blade, and the system preferably comprises a second stem support between the third and fourth grippers, wherein preferably the second stem support has a second elongated back support surface for support an elongated part of the stem of the different plant, wherein the second elongated support surface extends between the third and the fourth gripper, wherein more preferably the second stem support comprises a second slit for receiving the second blade for cutting the stem of the different plant, wherein the slit extends across the elongated support surface, wherein most preferably the slit and second slit are oriented parallel and wherein the blade and second blade mounted on the blade subframe, wherein the blades are oriented in parallel planes, wherein preferably the blade motor is arranged to move the blade subframe with blade and second blade into the slit and second slit.

9. System according to claim 8, wherein the system comprises a third gripper drive, a fourth gripper drive and a second stem support drive, and wherein the system is arranged to drive the third gripper drive to hold the stem of the different plant with the third gripper, to then drive the fourth gripper drive to hold the stem of the different plant with the fourth gripper, to then drive the second stem support drive to support the stem of the different plant with the second stem support and to subsequently drive the blade motor to cut the stem of the different plant with the second blade, wherein preferably the first and third gripper drives are formed by a single gripper drive and the first and third grippers are coupled to that single gripper drive, wherein preferably the second and fourth gripper drives are formed by a single second gripper drive and the first and third grippers are coupled to that single second gripper drive, wherein preferably the stem support drive and second stem support drive is formed by a single stem support drive and the stem supports are coupled to that single stem support drive.

10. System according to claims 8 or 9, wherein the first, second, third and fourth grippers are configured to align the stems of a scion-plant and a rootstock-plant along an axis parallel to said stems.

11. System according to any of the claims 5-10, wherein the blade, and preferably second blade, are connected to the blade subframe at proximal ends, and wherein respective blade edges extend from the respective proximal ends to the respective distal ends of the respective blades, wherein preferably the blades are mounted on a single blade mounting body, wherein preferably the blade converges towards the blade distal end, wherein preferably the blade edges of the blade and second blade extend in parallel planes, facing each other, wherein more preferably a distance between the blade edges of the blade and second blade increases towards the distal end.

12. System according to any of the claims 5-11, wherein the stem support has an elongated gutter for receiving a part of the stem of the plant, wherein preferably the elongated gutter extends between the first and second gripper and forms the stem support surface, wherein preferably the stem support is formed by two stem support bodies, wherein preferably the stem support has a stem support bodies drive for moving the stem support bodies with respect to each other, wherein preferably the slit is formed between the stem support bodies.

13. Method for preparing a plant stem section for grafting, the method comprising:

- providing stems of plants each having a free-end,

- holding by a first gripper the stem of the plant at a first location on the stem;

- holding by a second gripper the stem of the plant at a second location on the stem closer to the free-end;

- cutting the stem of the plant at a location on the stem between the first and second locations.

14. Method of according to claim 13, the method further comprising supporting the stem at third and fourth locations at a distance between the first and second locations, and wherein cutting the stem comprises cutting the stem between the third and fourth locations, wherein cutting preferably comprises moving a blade in a first direction through the stem, wherein the stem is supported on a backside with respect to the first direction, wherein preferably the first, second, third and fourth locations are aligned along the stem of the plant.

15. Method according to claim 13 or 14, wherein providing plants having a free-end comprises providing scion-plants and rootstock-plants, wherein the scion-plant is enclosed by the first and second gripper and wherein the method further comprises:

- holding the stem of the rootstock-plant by a third gripper at a first location on the stem of the rootstock-plant;

- holding the stem of the rootstock-plant by a fourth gripper at a second location on stem of the rootstock-plant closer to the free-end of the rootstock-plant; and

- cutting the stem of the rootstock-plant between the first and second location.

16. Method of according to claim 15, the method further comprising supporting the stem of the rootstock plant at third location, and preferably at a fourth location, at a distance between the first and second locations, wherein preferably cutting the stem of the rootstock-plant comprises cutting the stem between the third and fourth locations, wherein cutting preferably comprises moving a blade in a first direction through the stem of the rootstock-plant, wherein the stem of the rootstock-plant is supported on a backside with respect to the first direction, wherein preferably the first, second, third and fourth locations are aligned along the stem of the rootstock-plant.

17. Method of claim 15 or 16, wherein the held stem of the rootstock-plant and the held stem of the scion-plant are cut simultaneously by first and second blades, wherein preferably the stems of the scion-plant and the rootstock-plant held with aligned stems, wherein preferably the scion-plant and rootstock-plant are cut by driving the first and second blades through the stems of the scion- and rootstock-plant respectively, wherein preferably the first and second blade are mounted on a blade subframe and driving the first and second blades comprises driving the blade subframe, wherein driving the first and second blades comprises aligning the stems in a second direction, driving the first and second blades in a first direction, which is perpendicular to the second direction, and cutting the stems sidewardly in a third direction, wherein more the direction is at angle of between 20 and 70 degrees with respect to the second direction.

18. Method of any of the claims 14-17, further comprising bringing together the cut ends of the scion-plant and the rootstock-plant.

19. Method of claim 18, further comprising placing a graft element around the cut ends of the scion-plant and the rootstock-plant.