SE2250270A1

SE2250270A1 - System and method for phenotyping using horizontal imaging

Info

Publication number: SE2250270A1
Application number: SE2250270A
Authority: SE
Inventors: Nehe Ajit Sudhakar
Original assignee: Nehe Ajit Sudhakar
Priority date: 2022-02-28
Filing date: 2022-02-28
Publication date: 2023-02-28
Also published as: SE545021C2

Abstract

A system (10) for phenotyping plants (6a, 6b, 6c, 6d) in a field (2) comprising a plurality of rows (4a, 4b, 4c, 4d) of plants is provided, the system comprising: - an imaging device (20) oriented with its imaging axis (22) so as to image plants (6) from the side, - a screen (30) arranged spaced apart from and opposite to the imaging device (20) such that individual plants (6b) of one row (4b) of plants may pass between the screen (30) and the imaging device (20) to be imaged against the screen (30) as the system (10) is moved along the one row (4b) of plants, and - a deflector (40) configured to deflect plants (6a) of at least one other row (4a) of plants as the system (10) is moved along the one row (4a) of plants such that only plants (6b) of the one row (4b) of plants pass between the screen (30) and the imaging device (20). A method of phenotyping plants is also provided.

Description

SYSTEM AND METHOD FOR PHENOTYPING USING HORIZONTAL IMAGING Technical field The technology proposed herein relates generally the field of phenotyping plants and plant breeding. The technology proposed herein particularly relates to systems and methods for acquiring phenotypical data on plants growing in a field.

Background Plant breeding generally involves crossing or modifying plants to produce new plants that are better in performance (higher yield or resistance or tolerance). For that, plant researchers need to obtain information on certain parameters or traits or characteristics, i.e., the phenotype to choose plants to cross. Such crossing and modification may for example initially be performed in small numbers of plants in a laboratory, whereas larger number of plants later are grown in field conditions to evaluate whether the crossings or modifications have resulted in the desired traits, as well as to ascertain that no undesired traits have been obtained. Growing the plants in field conditions may further provide information on other traits. Traits of interest may for example include plant density, plant height, lodging, heading or flowering date, ear length, grain numbers size and shape in standing crops, leaf area, susceptibility to disease or pests, etc.

Generally, when plants are grown in field conditions these traits must be determined manually. Accordingly, workers move among the plants inspecting each plant to measure and record the traits for each specific plant. This is very tiring and monotonous work, and a mistake in measuring a trait or a failure to associate the measurement with the corresponding plant may lead to a failure to identify plants with desired traits.

Systems have thus been proposed for determining traits of plants with no or limited use of manual labour. Such systems typically employ cameras movably mounted on movable gantries for imaging the plants in the field from above, or cameras mounted on powered or manually moved carts also imaging the plants from above.

These systems currently have drawbacks. Larger gantry-based systems may comprise numerous cameras and other sensors for determining a wide variety of parameters and traits for the plants, but typically example require special infrastructure such as rails provided along the sides of the field. Smaller systems comprising cameras mounted on carts are less expensive but may lack sufficient sensors and cameras to obtain accurate data.

CN111750777A discloses a self-propelled crop phenotype high-throughput detection device. The device moves across seedlings in the detection process and phenotypic information is collected from above the crops.

US10959377B2 discloses a system for scanning crops vertically, i.e., from above the plants.

Objects The technology proposed herein aims at obviating or overcoming the aforementio- ned disadvantages. A primary object of the technology proposed herein is therefore to provide a A further object of the technology proposed herein is to provide Summary At least one of the abovementioned objects or at least one of the further objects which will become evident from the below description, are according to a first aspect of the technology proposed herein achieved by a system for phenotyping plants in a field comprising a plurality of rows of plants, the system comprising: - an imaging device oriented with its imaging axis so as to image plants from the side, - a screen arranged spaced apart from and opposite to the imaging device such that individual plants of one row of plants may pass between the screen and the imaging device to be imaged against the screen as the system is moved along the one row of plants, and - a deflector configured to deflect plants of at least one other row of plants as the system is moved along the one row of plants such that only plants of the one row of plants pass between the screen and the imaging device.

At least one of the abovementioned objects or at least one of the further objects which will become evident from the below description, is further, according to a corresponding second aspect of the technology proposed herein, achieved by a method of phenotyping plants in a field comprising a plurality of rows of plants, the method comprising steps of: i. providing a system according to any of the preceding c|aims on the field, ii. positioning the system such that a first plant of a one row of plants is positioned so as to pass between the screen and the imaging device, and iii. moving the system along the one row while imaging each plant of the one row of plants that passes between the screen and the imaging device.

Accordingly, the technology proposed herein is based on the discovery that imaging plants from the side significantly simplifies obtaining information on parameters and traits of the plants. The screen and deflector allow plants in a middle (i.e., second) row to be imaged because the screen prevents the camera device from imaging plants growing in the third row, i.e. behind the plant to be imaged in the second row, and the deflector deflects plants growing in a first row, i.e. in a row in front of the second row, from passing between the screen and the imaging device. ln particular, the technology proposed herein, by imaging the plants from the side, provides imaging of the whole plant, thus allowing significantly more parameters and traits to be determined using a given imaging device than prior art systems imaging plants from above.

This allows the imaging provided by the technology proposed herein to be used to determine the same or similar number of parameters as prior art gantry-based systems using a simple cart or cart-like mobile chassis, i.e., at a fraction of the cost and complexity.

Further, the technology proposed herein using the screen and deflector provides for determining parameters and traits for each and every plant in the field, regardless of whether a plant is situated within or on the border of a field or plot. There is thus no limitation that only plants positioned along the edge or border of a field or plot can be imaged. Further, there is no requirement that rows of plants be spaced apart sufficiently to allow a system of imaging sensor to pass between the rows.

The technology proposed herein further provides for imaging each plant separately, i.e., so that determined parameters and traits can be associated with the individual plant. This increases the accuracy of identifying plants having desired traits compared to systems which image the plants from above.

The system may be handheld, may comprise or be carried by a land vehicle such as a cart or mobile chassis, or may be comprised or carried by an air vehicle such as a helicopter. The system may further be provided with a positioning system such as a GPS unit, an inertial navigation system and/or wheel encoders (where the system comprises or is carried by a land vehicle) for determining the position of the system. Information regarding the position of the system may be associated with each imaged plant such that a plant, having certain parameters or traits as determined from imaging the plant using the system can later be identified and found and retrieved in the field for further study. Further possible positioning systems may use beacons, such as beacons emitting or reﬂecting light, sound or radio signals, placed at known positions in the field. The system is typically powered by a battery. The system may comprise, or be connected, preferably wirelessly, to a data storage or database for storing imaging information for each plant imaged. The data storage or database may comprise, or be connected to, a calculation device such as a personal computer or server for calculating and determining phenotyping data from the imaging information. Determined phenotyping data may be stored and presented Phenotyping plants comprises determining one or more parameters or traits related to a plant. Such parameters or traits are listed in table 1 below which also shows which imaging device is used to perform the imaging of the plant and obtain the imaging information used for determining the parameter: Table 1. parameters and traits Parameter (trait) Imaging device Tiller count/plant density, plant height, flowering, RGB camera (visible light) ear length, spikelet's numbers, leaf area, leaf rolling, leaf waxiness, leaf angle, stem diameter, lodging, canopy green area / biomass, canopy SeneSCenCe Leaf angle, plant architecture LiDAR Grain numbers, grain size, internode length X-ray camera Grain quality Hyperspectral camera Canopy temperature Thermal camera photosynthetic efficiency, disease presence, and Fluorescence camera weed presence The camera device may comprise one or more of the listed camera types in order to obtain one or more of the listed parameters.

The plants are grown in a field including a plurality of rows of plants. The field may be divided into plots, where each plot contains an area of plants or a number of adjacent rows. The field may be planted or seeded in rows so as to obtain generally parallel lines, i.e., rows, of plants. Alternatively, the field may be seeded or planted randomly whereby the plants are positioned randomly. ln either case at least two rows of plants within context of the technology proposed herein is obtained because a row of plants encompasses any two or more, preferably three or more, plants provided in line in the field. Thus, also when plants are provided randomly in the field, the plants are provided in a plurality of rows or plants.

The system may thus also be seen as a system for phenotyping plants in a field, and the method may thus also be seen as a method of phenotyping plants in a field. The one row of plants may thus be seen as one group of plants and the at least one other row of plants may thus be seen as another group of plants.

A number of adjacent rows may define a plot. A field may thus contain a plurality of plots, for example with different types of plants in each plot. One plot may for example contain individual wheat plants planted in rows, whereas another plot may contain individual barley plants planted in rows. The field is typically a field used for growing plants such as crops. The plant is typically a crop such as Rice, Maize (Corn), Wheat, Soybean, Potato, Tomato, Sugarcane, Grape, Seed Cotton, Apples, Onion, Cucumbers, Gherkins, Garlic, Banana, Oil palm fruit, Cassava (yuca), Rape, Barley, Olives, Sunflower, Cabbage, other brassicas, spinach, Strawberry, Tobacco, Coffee, Lettuce, Tea, Peas. Preferably the plant is selected from the group consisting of cereals such as barley, oats, rice, rye, spelt, teff, triticale, wheat and wild rice, and legumes such as beans, soybeans, peas, chickpeas, peanuts, lentils, lupins, mesquite, carob, tamarind, alfalfa, and clover. The plurality of rows is preferably at least two rows, such as at least 3 rows, typically at least 5 rows. The rows of plants are preferably parallel. The spacing between the rows may be from 5 cm up to 100 cm, such as from 5 cm up to 50 cm, more preferably from 10 cm up to 40 cm.

The imaging device obtains an image or representation of the plant. The imaging device preferably obtains an image by detecting radiation such as light reflected from the plant. The radiation may be ambient radiation such as visible light, IR radiation, UV radiation, etc., but may alternatively be radiation emitted from the imaging device and reflected on the plant. This further contemplated within the context of the technology proposed herein that the imaging device additionally may use radio signals (radar) or ultrasound (ultrasound distance sensing) to obtain a representation of the plant. The imaging device may be configured to a single image of each plant but may alternatively be configured for continuously or semi continuously obtain images, i.e., as a video stream of images.

The imaging device is oriented with its imaging axis so as to image plants (6) from the side. The angle between the imaging axis and a horizontal axis is preferably from -30° to +30°, more preferably from -10° to +10°, even more preferably from - 5° to +5°. Most preferred is when the angle between the imaging axis and a horizontal axis is substantially 0°, i.e., when the imaging axis is horizontal. The angle between the imaging axis and the longitudinal axis, i.e., height axis of the plant is correspondingly preferably from 60° to 120°, more preferably from 80° to 100°, even more preferably from 85° to 95°, most preferably 90°. This ensures that the plant can be imaged from the side.

When the system is positioned to such that a first plant of a one row of plants is positioned so as to pass between the screen and the imaging device, then the imaging axis is generally at a right angle to the extension of the row. This allows each plant in the row to be imaged from the side, and it also allows the system to be moved along the row.

The screen has the purpose of providing a background to the plant being imaged, and to screen, e.g., cover, any plants or other objects positioned behind the plant that is to be imaged in the direction of the imaging axis. The screen thus also partially serves to ensure that only the plants in the one row pass between the screen and the imaging device. The screen is preferably planar and oriented such that the axle between the normal of the screen and a horizontal axis is from -30° to +30°, more preferably from -10° to +10°, even more preferably from -5° to +5°. Most preferred is when the angle between the normal of the screen and a horizontal axis is substantially 0°, i.e., when the screen is vertical. The screen preferably is sized such that it covers to the imaging field of the imaging device at the distance that the screen is positioned from the imaging device. ln other words, the screen is preferably sized such that the imaging device, when obtaining an image, does not image anything outside the edge of the screen. The size of the screen may be adapted based on the size of the plants to be imaged. Typically, the screen may have a height of from 40 to 300 cm and a width of from 20 to 100 cm. The screen is typically rectangular.

The screen may be a planar sheet of material such as a planar sheet of plastics or metal. The screen preferably is coloured in a uniform colour, for example white, grey, or black, to provide a uniform background to the plant being imaged. The screen may be provided with indicia such as a grid or line pattern of known dimensions to provide a reference in images obtained by the imaging device. Preferably the screen is configured to provide a uniform background to plants being imaged by the imaging device.

The screen is arranged spaced apart from and opposite to the imaging device. This provides the imaging device with sufficient separation from the screen to be able to image at least a major part, preferably all of, the plant.

The distance between the screen and the imaging device is sufficient such that individual plants of one row of plants may pass between the screen and the imaging device. The distance may thus be adapted to the type of plant being imaged. The distance may for example be from 20 cm to 100 cm. Preferably the system, in use, is positioned and moved along the one row such that the plants pass closer to the screen than to the imaging device. This allows more of the plant to be imaged. ln use, the individual plants of the one row pass between the screen and the imaging device and are imaged against the screen. Preferably each individual plant is imaged alone, however it is further contemplated that, depending on the field of view of the imaging device at the screen, more than one plant may be imaged at the same time. This decreases the number of images that are needed to image the plants in the row but may require further steps if the parameters determined from the images is to be associated with the corresponding individual plant. The plants are imaged against the screen meaning that the screen provides a background to the plant being imaged.

The system, in particular the screen, the imaging device, and the deﬂector, may be moved in a continuous motion along the one row of plants. Alternatively, the system is moved stepwise. The imaging device may be configured for continuous, semicontinuous, or single image acquisition of images. The system may comprise a detector for detecting whether a plant is present between the screen and the imaging device. Such a detector may comprise any of a photocell detector detecting when a light beam emitted between the screen and the imaging device is broken by a plant. Alternatively, the detector may be implemented as an algorithm taking image information, for example a video stream, from the imaging device and being configured to detect the presence of a plant from the image information. Further alternatively, the detector may be implemented as a switch actuated by a thin rod extending into the space between the screen and the imaging device, the rod being bent or pivoted out of the way by the plant as the plant passes into the said space.

The deflector is configured to deflect plants of at least one other row of plants. The deflector may deflect plants by pushing them to the side, i.e., in the direction away from the one row and away from the screen. As evident from the above discussion of randomly planted fields, the at least one other row of plants need not be parallel to the one row of plants. Further, the at least one other row of plants need not have the same spacing between plants as the one row. Alternatively worded the deflector is configured to deflect plants which are planted adjacent the one row but not in the one row. The deﬂector may comprise a first wedge attached at the imaging device and extending parallel with the screen with its sharp end pointing away from the imaging unit. Preferably the deflector comprises a rod having a mounting part extending parallel to the screen and being attached at the imaging device and a leading part connected at an angle to the mounting part, the leading part extending away from the imaging unit and towards the screen at an angle. As the system is moved along the one row, plants in the row behind the one row will pass behind the screen whereas plant in the row in front of the one row will contact the deflector, i.e., the wedge or the second leading part, and be pushed to the side, i.e., bended out of the way, thus providing space for the imaging device to image the plants in the one row without interference from the plants in the row in front of the one row. The deflector may further comprise a second wedge or trailing part provided and oriented opposite to first wedge or leading part so as to prevent the deflected plants from suddenly springing back to a vertical non- deflected and non-bent position. By providing the second wedge or trailing part each deflected plant gradually regains its non-deflected orientation as the system passes the plant. The deflector may in particular be configured so as to deﬂect plants regardless of which direction along the one row of plants that the system is moved. The second wedge or trailing part may therefore preferably have the same dimensions and configuration as the first wedge and leading edge but oriented in the opposite direction.

The distance between the deflector and the screen may be adapted based on the circumference or diameter of the plants. Where the deflector comprises a first wedge or leading part, the minimum distance between the tip of the wedge or the leading part, and the screen may preferably correspond at least to the maximum diameter of the plants in the one row. Typically, depending on the plant, this distance may be from 10 cm to 60, preferably from 10 cm to 30 cm.

The deflector, and partially also the screen, ensures that only plants of the one row of plants pass between the screen and the imaging device. lt is contemplated that a further deflector may be arranged at the screen and configured to deﬂect plants in the row behind the screen away from the screen. Such a further deﬂector may be used to provide for an increased distance between the screen and the imaging device. Thus, the system may comprise both a deflector and a further deflector for deflecting plants in neighbouring rows to the one row away from the one row.

Preferably, the imaging device comprises one or more of a visible light (RGB) camera, a hyperspectral camera, a thermal camera, a fluorescence camera, an X- ray camera, and a LiDAR. These devices may be used to obtain the parameters listed in table 1 above. An RGB camera is a camera obtaining images in the visible light spectrum, preferably wavelengths of 380 to 750 nm. A hyperspectral camera preferably obtains images in the wavelength spectrum of 350 to 1000 nm. A thermal camera obtains images in the IR wavelength spectrum from 1000 nm to 14000 nm. A ﬂuorescence camera uses a light source to cause fluorescence in the plant and obtains an image based upon fluorescence of the plant. An X-ray camera obtains X-ray images and may comprise an X-ray radiation source. A LiDAR scans an area using laser light and The system may further comprise: - a radiation source arranged at the imaging device and configured to emit radiation towards the screen, wherein the screen comprises a radiation detector for detecting radiation emitted by the radiation source.

This provides a further device and method of obtaining image information for a plant. The radiation source may be an X-ray radiation source or source of other type of radiation capable of being emitted from the radiation source and capable of travelling to the screen around or through the plant. The radiation detector is consequently preferable an X-ray panel detector. 11 The screen is preferably spaced apart from the imaging device by a distance that at least corresponds to the distance between adjacent rows of plants in the field. This is a suitable distance between screen and imaging device.

Preferably the system further comprises: - a bracket carrying the imaging device, the screen, and the deflector. lt is advantageous to use a bracket for carrying, e.g., supporting, the imaging device, the screen, and the deflector. The bracket fixes the relative position of the screen in relation to the imaging device, and the relative position of the deﬂector in relation to the screen, and thus makes it easier to concertedly move the screen, imaging device and deflector along the one row of plants. The imaging device, the screen and the deflector may each be fastened directly to the bracket. Alternatively, the imaging device, the screen and the deflector are attached to the bracket via hinged, pivotable and/or extendable mechanical connections for allowing the distance between the imaging device, the screen, and the deflector, and/or the orientation of the respective component, to be varied.

The bracket may for example be shaped as an inverted U having a top member for carrying the system and first and second parallel side members, one side member being used to carry the screen, and the other being used to carry the imaging device and the deflector.

Although the system can be handheld or carried by an air vehicle such as a drone, it is preferred that system further comprises - a mobile chassis carrying the bracket, the mobile chassis further comprising wheels or tracks for moving the mobile chassis over the field.

The mobile chassis may be self-propelled or towed/pushed. The mobile chassis preferably comprises at least 3, preferably 4, wheels or two tracks. The wheels and tracks are preferably configured to run in the lanes between the rows of plants in the field.

Preferably the mobile chassis comprises: - a horizontal rectangular frame, 12 - vertically oriented wheeled or tracked posts attached and configured to carry the horizontal rectangular frame, - a gantry spanning the distance between two opposing sides of the horizontal rectangular frame, the gantry being configured to be moveable along the two opposing sides, and - a carriage configured to be movable along the gantry and further configured to carry the bracket. The horizontal rectangular frame if preferably carried, at a height that is higher than the length of the plants in the field, by the vertically oriented wheeled or tracked posts. Typically, four posts are provided, one at or near each corner of the frame. The gantry may be provided with bearings at its end to run along the two opposing sides of the frame. An actuator may be provided on the gantry or on the frame to cause movement of the gantry. A wire may for example extend along each of the two opposing sides and the actuator, mounted on the gantry, may be configured to pull on said wire to cause movement of the gantry. Alternatively, the actuator may comprise a pinion and the two opposing sides of the frame be provided with toothed racks such as rotation of the pinion causes the gantry to traverse along the opposing sides. The carriage may comprise roller for along it to roll along the gantry. A further actuator may be provided for moving the carriage using for example a wire arrangement or pinion and toothed rack arrangement as described above.

Preferably -the carriage comprises a hoisting mechanism for adjusting the height of the bracket relative to the frame, and/or - a hoisting mechanism is provided between each post and the frame for adjusting the height of the frame relative to the field. This is advantageous in that it allows the system to be for plants having different heights. lt is not uncommon that a single field is used to grow different plants, e.g., in different plots. By providing the hoisting mechanism the height of the imaging unit, screen and deflector can be varied so as to adapt to differently sized plants. The hoisting mechanism may for example comprise a hydraulic or pneumatic piston and cylinder device, a rack and pinion device, a rack and worm gear device, etc. 13 ln use the system is first positioned such that a first plant of a one row of plants is positioned so as to pass between the screen and the imaging device. This system is thus lined up such that it can be moved along the one row or plants. The system is then moved along the one row of plants while imaging each plant of the one row of plants that passes between the screen and the imaging device. lf the one row is the first, i.e., outermost, row of a plot or field, then there are generally no plants to deflect. However, if a further deﬂector is arranged at the screen as described above, then the plants of the second row behind the first row may be deflected.

Further, as soon as the one row is the second row in the plot or field, there will be a first row of plants in front to the one row. Then the method further comprises the step of: iv. deflecting plants of at least one other row of plants while the system is moved along the one row of plants such that only plants of the one row of plants pass between the screen and the imaging device. lf the further deflector is arranged at the screen as described above, then the plants of the third row behind the second row would be deflected.

Preferably: v. the imaging device comprises an RGB camera and the method comprises imaging each plant of the first row of plants using the RGB camera and determining, for each plant, one or more parameters selected from the group consisting of tiller count/plant density, plant height, flowering, ear length, spikelet's numbers, leaf area, leaf rolling, leaf waxiness, leaf angle, stem diameter, lodging, canopy green area / biomass, canopy senescence, and/or vi. the imaging device comprises a LiDAR and the method comprises imaging each plant of the first row of plants using the LiDAR and determining, for each plant, one or more parameters selected from the group consisting of leaf angle and plant architecture, and/or vii. the imaging device comprises an X-ray camera and the method comprises imaging each plant of the first row of plants using the X-ray camera and determining, for each plant, one or more parameters 14 selected from the group consisting ofgrain numbers, grain size, and internode length, and/or viii. the imaging device comprises a hyperspectral camera and the method comprises imaging each plant of the first row of plants using the hyperspectral camera and determining, for each plant, the parameter grain quality, and/or ix. the imaging device comprises a thermal camera and the method comprises imaging each plant of the first row of plants using the thermal camera and determining, for each plant, the parameter canopy temperature, and/or x. the imaging device comprises a fluorescence camera and the method comprises imaging each plant of the first row of plants using the fluorescence camera and determining, for each plant, one or more parameters selected from the group consisting of photosynthetic efficiency, disease presence, and weed presence.

A further aspect of the technology proposed herein relates to the use of: - a system comprising: - an imaging device oriented with its imaging axis so as to image plants from the side, - a screen arranged spaced apart from and opposite to the imaging device such that individual plants of one row of plants may pass between the screen and the imaging device to be imaged against the screen as the system is moved along the one row of plants, and - a deflector configured to deflect plants of at least one other row of plants as the system is moved along the one row of plants such that only plants of the one row of plants pass between the screen and the imaging device, for phenotyping plants in a field comprising a plurality of rows of plants, Brief description of the drawinqs and detailed description A more complete understanding of the abovementioned and other features and advantages of the technology will be apparent from the following detailed description of preferred embodiments in conjunction with the appended drawings, wherein: Fig. 1A shows a top view of a first embodiment of the system according to the first aspect of the technology proposed herein.

Fig. 1B shows a side view of the first embodiment of the system according to the first aspect of the technology proposed herein. shows a front view of the first embodiment of the system according to the first aspect of the technology proposed herein.

Fig. 1D shows a top view of a second embodiment of the system according to the first aspect of the technology proposed herein.

Fig. 2A shows a top view of the first embodiment of the system according to the first aspect of the technology proposed herein as the system is positioned ready to image plants of a first row of plants in the method according to the second aspect of the technology proposed herein. shows a top view of the first embodiment of the system according to the first aspect of the technology proposed herein as the system moves along the first row of plants while imaging each plant of the first row of plants in the method according to the second aspect of the technology proposed herein.

Fig. 2C shows a top view of the first embodiment of the system according to the first aspect of the technology proposed herein as the system moves along the second row of plants while imaging each plant of the second row of plants and deflecting plants of the adjacent first row of plants in the method according to the second aspect of the technology proposed herein. 16 Fig. 3 shows a further embodiment of the system further comprising a mobile chassis.

Fig. 1A shows a top view of a first embodiment of the system 10 according to the first aspect of the technology proposed herein. The system 10 comprise an imaging device 20 arranged with its imaging axis 22 oriented so as to image plants from the side. A screen 30 is provided spaced apart and opposite the imaging device 20 as to provide a background against which individual plants, one being designated the reference numeral 6a, of one row of plants may pass to be imaged. A def|ector 40 is provided for def|ecting plants, one of which is designated the reference numeral 6b, see Fig. 1C and 2A, of at least one other row of plants as the system (10) is moved along the one row of plants such that only plants 6a of the one row of plants pass between the screen 30 and the imaging device 20. The def|ector 40 is configured as a rod and comprises a mounting part 42 and a leading part 44, the leading part 44 being angled towards the screen 30 so as to guide and push plants 6b of the other row away from the screen 30 and keep the plants 6b out of the way of the imaging device 20, as the system 10 is moved along the one row and images the plant 6a The system 10 shown in Fig. 1A-1C further comprises a bracket 50 to which the imaging device 20, the screen 30, and the def|ector 40 are attached. The bracket 50 comprises a top member 52 for carrying the system and first and second parallel side members 54 and 56, one side member 54 being used to carry the screen, and the other side member 56 being used to carry the imaging device 20 and the def|ector 40.

Fig. 1B shows a side view of the first embodiment of the system 10. The size of the screen 30 may be adapted depending on the size of the plants to be imaged.

Fig. 1C shows a front view of the first embodiment of the system 10. As seen in the figure plant 6a of one row 4a of plants pass between the imaging device 20 and the screen 30 to be imaged, whereas plants 6b of another, neighbouring row 4b of plants are deflected, i.e., pushed or bent to the side away from the screen 30 so as to not impede the imaging of the plant 6a. Further shown in Fig. 1C is the ground of the field 2 in which the plants are grown. 17 Fig. 1D shows a top view of a second embodiment of the system 10' according to the first aspect of the technology proposed herein. This embodiment differs by having a deflector 40' which in addition to the leading part 44 also has a trailing part 46 being ang|ed similarly to the leading part 44 but in the other direction. The trailing part 46 provides that the system 10' can be moved in either direction along the row of plants, and further ensures that deflected plants are allowed to gradually regain their normal upright position as the system passes the plant, thereby preventing damage to the plants from sudden movement. in addition to the deﬂector 40', the system 10' may further have a modified imaging device 20' comprising a source of radiation and a modified screen 30' having a detector for detecting radiation and thus providing further image information on the plant.

Fig. 2A shows a top view of the first embodiment of the system 10 according to the first aspect of the technology proposed herein as the system is positioned ready to image plants of a first row of plants in the method according to the second aspect of the technology proposed herein.

The field 2 comprises a plurality of rows 4a, 4b, 4c, 4d of plants. ln Fig. 2A the system 10 is positioned at the start of the first row 4a so as to start the imaging of plants 6a in that row.

Fig. 2B shows a top view of the first embodiment of the system according to the first aspect of the technology proposed herein as the system moves along the first row 4a of plants while imaging each plant 6a of the first row of plants in the method according to the second aspect of the technology proposed herein.

As seen, each plant 6a of the first row 4a of plants sequentially pass between the imaging device and the screen to be imaged. As this is the first row, and there are no rows in front, the deflector 40 of the system 10 is inactive, i.e., it does not deflect any plants. The screen 30 screens the plants 6b in the second row 4b behind the first row 4a.

Fig. 2C shows a top view of the first embodiment of the system 10 according to the first aspect of the technology proposed herein as the system moves along the second row 4b of plants while imaging each plant 6b of the second row 4b of 18 plants and deflecting plants 6a of the adjacent first row 4a of plants in the method according to the second aspect of the technology proposed herein.

Whereas in Fig. 2B plants of the first row 4a of plants were imaged, Fig. 2C shows how plants of the second row of plants are imaged. Specifically, the deflector 40 serves to deflect, i.e., bend or push, plants 6a of the first row 4a away from entering and passing between the screen 30 and the imaging device 20, so as to ensure that only plants of the second row 4b of plants 6b are imaged.

After imaging plants of the second row 4b, the system 10 may move along and image plants of the third row 4c of plants while deflecting at least the plants 6b in the second row. Thus, when imaging plants in row x the system at least deflects plants in row X-1, i.e., the row in front of row X, and screens plants in rows >= x+1.

Further, whereas Fig 2C shows how plants in parallel rows 4a-4d are imaged, it is also evident that the system 10 works also when the system is moved along an arbitrary row of plants, e.g., as illustrated by arbitrary rows 4a' and 4b'. Specifically, if system 10 is moved along row 4a' or 4b', the deflector will in any case deflect plants planted adjacent to, but not in, the rows 4a' and 4b'. Thus, even fields planted randomly will comprise at least two rows of plants, i.e., at least two or more plants planted in a line.

Fig. 3 shows a further embodiment of the system 10" further comprising a mobile chassis 60 comprising a horizontal rectangular frame 70 carried by vertically oriented posts, one of which is designated the reference numeral 80 provided with wheels 82, the system further comprising a gantry 90 spanning the distance between two opposing sides 72, 74 of the horizontal rectangular frame 70, the 90 gantry being configured to be moveable along the two opposing sides 72, 74 using wheels, one of which is designated the reference numeral 92. A carriage 100 is mounted on the gantry 90 and a carriage configured to be movable along the gantry 90 using wheels, one of which is designated the reference numeral 102, and further configured to carry, via a hoisting mechanism 110 having mating telescopic first and second parts 112 and 114, the bracket 50 and thereby the imaging device 20, screen 30 and deﬂector 40. The moveable chassis 60 may thus move over the field 2 until it reaches one or more rows of plants to image, 19 and then the imaging device 20, screen 30 and deflector 40 can be moved along the rows of plants either by moving the moveable chassis 60, or by moving the bracket 50 in relation to the frame 70 using the gantry 90 and the carriage 100. The hoisting mechanism 110 may be used to adjust the height of the imaging device 20.

Feasible modifications of the technoloqv proposed herein The technology proposed herein is not limited to the embodiments described above and shown in the drawings, which primarily have an illustrative and exemplifying purpose. This patent application is intended to cover all adjustments and variants of the preferred embodiments described herein, thus the present invention is defined by the wording of the appended claims and the equivalents thereof. lt shall also be pointed out that all information about/concerning terms such as above, under, upper, lower, etc., shall be interpreted/read having the equipment oriented according to the figures, having the drawings oriented such that the references can be properly read. Thus, such terms only indicate mutual relations in the shown embodiments, which relations may be changed if the inventive equipment is provided with another structure/design. lt shall also be pointed out that even thus it is not explicitly stated that features from a specific embodiment may be combined with features from another embodiment, the combination shall be considered obvious, if the combination is possible.

Throughout this specification and the claims which follows, unless the context requires otherwise, the word "comprise", and variations such as "comprises" or "comprising", will be understood to imply the inclusion of a stated integer or steps or group of integers or steps but not the exclusion of any other integer or step or group of integers or steps.

Claims

1. A system (10) for phenotyping plants (6a, 6b, 6c, 6d) in a field (2) comprising a plurality of rows (4a, 4b, 4c, 4d) of plants, the system comprising: - an imaging device (20) oriented with its imaging axis (22) so as to image plants (6) from the side, - a screen (30) arranged spaced apart from and opposite to the imaging device (20) such that individual plants (6b) of one row (4b) of plants may pass between the screen (30) and the imaging device (20) to be imaged against the screen (30) as the system (10) is moved along the one row (4b) of plants, and - a deflector (40) configured to deflect plants (6a) of at least one other row (4a) of plants as the system (10) is moved along the one row (4a) of plants such that only plants (6b) of the one row (4b) of plants pass between the screen (30) and the imaging device (20).

2. The system (10) according to claim 1, wherein the imaging device (20) comprises one or more of a visible light (RGB) camera, a hyperspectral camera, a thermal camera, a fluorescence camera, an X-ray camera, and a LiDAR.

3. The system (10) according to any preceding claim, further comprising, - a radiation source (20') arranged at the imaging device and configured to emit radiation towards the screen (30'), and wherein the screen (30') comprises a radiation detector for detecting radiation emitted by the radiation source.

4. The system (10) according to any preceding claim, wherein the screen (30) is configured to provide a uniform background to plants (6b) being imaged by the imaging device (20).

5. The system (10) according to any of the preceding claims, further comprising, - a bracket (50) carrying the imaging device (20), the screen (30), and the deflector (40).

6. The system (10") according to claim 5, further comprising:- a mobile chassis (60) carrying the bracket (50), the mobile chassis (60) further comprising wheels (82) or tracks for moving the mobile chassis (60) over the field (2).

7. The system (10) according to claim 6, wherein the mobile chassis (60) comprises: - a horizontal rectangular frame (70), - vertically oriented wheeled or tracked posts (80) attached and configured to carry the horizontal rectangular frame (70), - a gantry (90) spanning the distance between two opposing sides (72, 74) of the horizontal rectangular frame (70), the gantry (90) being configured to be moveable along the two opposing sides (72, 74), and - a carriage (100) configured to be movable along the gantry (90) and further configured to carry the bracket (50).

8. The system according to claim 7, wherein -the carriage (100) comprises a hoisting mechanism (110) for adjusting the height of the bracket (50) relative to the frame (70), and/or - a hoisting mechanism is provided between each post (80) and the frame (70) for adjusting the height of the frame (70) relative to the field (2).

9. A method of phenotyping plants (6) in a field (2) comprising a plurality of rows (4a, 4b, 4c, 4d) of plants, the method comprising steps of: i. providing a system (10) according to any of the preceding claims on the field (2), ii. positioning the system (10) such that a first plant (6b) of a one row (4b) of plants is positioned so as to pass between the screen (30) and the imaging device (20), and iii. moving the system (10) along the one row (4b) while imaging each plant (6b) of the one row of plants that passes between the screen (30) and the imaging device (20).

10. The method according to claim 9, further comprising the step of:deflecting plants (6a) of at least one other row (4a) of plants while the system (10) is moved along the one row (4b) of plants such that only plants of the one row of plants pass between the screen (30) and the imaging device (20).

11. The method according to any of claims 9-10, wherein: V. vii. viii. the imaging device (20) comprises an RGB camera and the method comprises imaging each plant of the first row of plants using the RGB camera and determining, for each plant, one or more parameters selected from the group consisting of tiller count/plant density, plant height, flowering, ear length, spikelet's numbers, leaf area, leaf rolling, leaf waxiness, leaf angle, stem diameter, lodging, canopy green area / biomass, canopy senescence, and/or the imaging device (20) comprises a LiDAR and the method comprises imaging each plant of the first row of plants using the LiDAR and determining, for each plant, one or more parameters selected from the group consisting of leaf angle and plant architecture, and/or the imaging device (20) comprises an X-ray camera and the method comprises imaging each plant of the first row of plants using the X-ray camera and determining, for each plant, one or more parameters selected from the group consisting of grain numbers, grain size, and internode length, and/or the imaging device (20) comprises a hyperspectral camera and the method comprises imaging each plant of the first row of plants using the hyperspectral camera and determining, for each plant, the parameter grain quality, and/or the imaging device (20) comprises a thermal camera and the method comprises imaging each plant of the first row of plants using the thermal camera and determining, for each plant, the parameter canopy temperature, and/or the imaging device (20) comprises a fluorescence camera and the method comprises imaging each plant of the first row of plants using the fluorescence camera and determining, for each plant, one or moreparameters selected from the group consisting of photosynthetic efficiency, disease presence, and weed presence.