System and method for illuminating plurality of plants

Abstract

Systems and methods for illuminating a plurality of plants (11) are disclosed. The system (1) comprises an illumination system (3) configured to illuminate a plurality of plants (11) with radiation having one or more controllable radiation properties, and a data processing system (100) communicatively connected to the illumination system (3). A data processing system (100) comprises an input interface for receiving a signal indicative of a status of a plant canopy, an output interface for sending a control signal to an illumination system, and a processor. The processor is configured to: receive a signal indicative of a status of a plant canopy formed by a plurality of plants (11); determining whether the plant canopy is closed based on the received signal indicative of the status of the plant canopy; and sending a control signal to the illumination system (3), the control signal being based on the determined canopy closure. The illumination system (3) is configured to switch from illuminating the plurality of plants (11) according to a first radiation recipe to illuminating the plurality of plants (11) according to a second radiation recipe different from the first radiation recipe based on the received control signal.

Description

Technical Field

[0001] This disclosure relates to a system and method for irradiating multiple plants, and more particularly to a system in which an irradiation formulation is determined based on plant properties. This disclosure also relates to a computer-implemented method for irradiating multiple plants, as well as a computer program and computer-readable storage medium for performing this method. Background Technology

[0002] Indoor food production in vertical farms (VFs) is only economically viable if plant growth can be completed efficiently year-round. Light utilization efficiency (LUE), which links biomass production to the total amount of light used in production, and crop quality (e.g., post-harvest shelf life) are key value drivers. Therefore, there is a need in this field to improve light utilization efficiency without negatively impacting crop quality.

[0003] One aspect of reduced light utilization efficiency is that, during the first growth stage, immediately after transplanting seedlings from high-density trays to low-density trays, a (relatively large) portion of the radiation ultimately reaches between the plants. While this light may acquire new variations that are absorbed by the leaves after being scattered or reflected on the tray surface, some light energy is lost, resulting in suboptimal light utilization efficiency.

[0004] CN112015212A describes a system that uses a camera to identify plant canopy information (such as plant biomass, canopy shape, canopy area, or plant location); determines the luminous area of ​​a lighting device corresponding to the luminous area covering the canopy; and controls the lighting device based on the plant canopy information to control the illumination in the luminous area. However, this requires specific lighting devices that can adjust their luminous areas very precisely, which most lighting devices on the market cannot do.

[0005] US 11089736 B2 describes a horticultural lighting device comprising different groups of LEDs, each group adapted to produce an emission spectrum with different peak wavelengths. The horticultural lighting device also includes a forward sensor in the form of a low-resolution monochrome CMOS device for measuring plant density. When the measured plant density reaches a predetermined level, this indicates that the spectrum should be changed to the next spectrum required in the plant's growth cycle, which can be accomplished via control software through automatic switching of the arrangement.

[0006] In view of the above, there is a need in the art for systems and methods for irradiating multiple plants that increase light utilization efficiency. Summary of the Invention

[0007] To this end, a system for irradiating multiple plants is disclosed. The system includes an irradiation system configured to irradiate multiple plants with radiation having one or more controllable radiation properties, and a data processing system communicatively connected to the irradiation system. The data processing system includes an input interface for receiving signals indicating the state of the plant canopy, an output interface for sending control signals to the irradiation system, and a processor. The processor is configured to receive signals indicating the state of the plant canopy formed by the multiple plants, determine whether the plant canopy is closed based on the received signals indicating the state of the plant canopy, and send control signals to the irradiation system based on the canopy being determined to be closed. The irradiation system is configured to switch from irradiating the multiple plants according to a first radiation formulation to irradiating the multiple plants according to a second radiation formulation different from the first radiation formulation, based on the received control signals.

[0008] The state of a plant canopy can refer to factors such as the canopy's coverage area, density, adjacency of plant regions, or various related parameters or combinations thereof. For example, the canopy's coverage area can be defined as the ratio of the projected canopy area to the ground (tray) area (e.g., in meters). 2 (Percentages). The density of the canopy canopy can be determined, for example, using light sensor data, based on the different absorption and reflection properties of the canopy and the background. The adjacency of the canopy can be defined, for example, the number of plants overlapping in the canopy, or the number of adjacent regions in the canopy (which starts with the number of plants and decreases to 1 when all plants are in contact with each other). The state of the canopy can be determined based on data representing only a portion of the canopy (e.g., the camera's field of view). The state of the canopy can also be based, for example, on a binary state corresponding to human input, typically "closed" and "unclosed".

[0009] Typically, an irradiation system is configured to irradiate multiple plants according to a first irradiation formula if the processor has determined that the canopy is not closed, and to irradiate multiple plants according to a second irradiation formula if the processor has determined that the canopy is closed. Typically, the first light formula (i.e., before the canopy closes) is optimized for plant growth (especially lateral growth) because light not absorbed by the canopy may be wasted, resulting in relatively low light utilization efficiency (LUE). However, once the canopy closes, virtually all available light is absorbed by the canopy, and therefore the second light formula can be optimized to stimulate different aspects of plant growth (e.g., dense growth, production of more valuable assimilates, etc.).

[0010] An irradiation system may include one or more controlled radiation sources, and / or one or more controlled radiation filters and / or radiation concentrators (which may be combined with "fixed" radiation sources, i.e. radiation sources that provide radiation with fixed radiation properties).

[0011] In one aspect, this disclosure relates to a horticultural arrangement including such a system. The term "horticultural arrangement" particularly refers to an arrangement including plant supports in which or on which plants may grow, an irradiation system configured to direct (horticultural) radiation toward the plant supports in which or on which plants may grow (or be grown), and a control system for controlling the (horticultural) radiation. The control system may include a data processing system or be communicatively connected to a data processing system.

[0012] In practice, garden arrangements may include plant supports with plants, plant supports with seeds, or plant supports with seedlings, etc. In this document, the term "plant" is used for virtually all stages of plant development.

[0013] Growth radiation typically includes a mixture of red and blue radiation. Red radiation can be understood as radiation with wavelengths between 600 and 700 nm, while far-infrared radiation can be understood as radiation with wavelengths between 700 and 780 nm. Blue radiation can be understood as radiation with wavelengths between 400 and 500 nm, and may include deep blue radiation, which can be understood as radiation with wavelengths between 400 and 425 nm. Green radiation can be understood as radiation with wavelengths between 500 and 600 nm. Radiation with wavelengths shorter than 400 nm, especially radiation with wavelengths between 10 and 400 nm, can be called ultraviolet radiation. Radiation with wavelengths greater than 780 nm can be called infrared radiation; in particular, radiation with wavelengths between 780 and 2500 nm can be called near-infrared radiation.

[0014] Specifically, the term "horticultural radiation" refers particularly to radiation having one or more wavelengths in a first wavelength region of 625-675 nm and a second wavelength region of 400-475 nm. Additionally, green or white light may be added. The relative energy provided in these regions (in, for example, W / m²) 2The amount of radiation (represented by the plant) can vary depending on the plant type and / or growth stage. Therefore, for one or more plant types, the formulation can optionally define the ratio based on time. Specifically, the term "horticultural radiation" can refer to the PAR region (from the photosynthetically active region of 400-700 nm, i.e., red + green + blue). The term "horticultural radiation" can also be used for radiation applied to plants in solution culture applications. As is known in the art, in the PAR region, the reflectance of leaves is very low (5-10% for red and blue light, 15-25% for green light). Towards the far-red and near-infrared, above 700 nm, the reflectance increases. Therefore, in certain embodiments, in addition to PAR radiation, horticultural radiation may also include a small fraction (e.g., ≤25% power, especially approximately at most 10% power) of far-red (i.e., 700-780 nm) and near-infrared (e.g., 750-850 nm).

[0015] When pre-harvest radiation is provided, it typically means stressing the plant so that it will respond by producing compounds of interest (e.g., nutrients, colorants, flavor compounds, etc.). This pre-harvest radiation usually comprises mostly blue radiation (e.g., about 450 nm) and / or UV-A radiation (i.e., radiation with wavelengths between 315–400 nm (e.g., 385–400 nm)) and / or more than 50 µmol m −2 s −1 The level of radiation. In some cases, UV-B radiation can also be beneficially applied. Generally, plants can be sensitive to both the absolute intensity of certain wavelengths and the relative intensity of different wavelengths.

[0016] The term "horticultural arrangement" can also refer to a plant farm or climate unit, in which plants are grown under controlled conditions and where the plants receive virtually no natural radiation (sunlight). Furthermore, such a plant farm can be climatized, for example, in the case of a climate unit. Therefore, in embodiments, a horticultural arrangement includes such a plant farm or climate unit. In other embodiments, a plant farm or climate unit includes at least a portion of a horticultural arrangement. For example, a climate unit may include plant supports and an illumination system, and a control system may be configured inside or outside the climate unit. In particular, a plant farm may include a climate unit.

[0017] The control system for this horticultural arrangement can control one or more of the following: temperature, humidity, CO2 level, irrigation, nutrient supply, horticultural radiation intensity (irradiance), and air conditions including one or more of air temperature, air composition, and airflow. The radiation intensity received by multiple plants can be expressed as, for example, the physical quantity "irradiance" (usually expressed in W / m²). 2 (represented as) or "photon flux density" (usually expressed in µmol / (m²)). 2(s) indicates). This horticultural system can be configured to control one or more of these conditions at different locations within the arrangement. Therefore, in an embodiment, irradiation with horticultural radiation can be responsive to one or more of, for example, time of day, season of year, (local) irradiation conditions, plant age, plant condition, planting period, etc. Therefore, in an embodiment, irradiation with horticultural radiation can be responsive to plant-related data, time-related parameters, and conditions experienced by the plant (such as natural radiation, temperature, relative humidity, CO2 level, irrigation, nutrient supply, etc.).

[0018] Horticultural irradiation systems are specifically configured to provide horticultural radiation to plants. This can specifically mean that the horticultural irradiation system is configured to provide horticultural radiation in the direction of a plant support in which or on which plants can grow. Such a plant support can be a tray. In particular, the term "plant support" can also refer to multiple plant supports, as plants can grow in layers ("multilayer system"). Thus, every two or more plant supports have a frame, and each plant support has a radiation system. Therefore, the term "irradiation system" can also refer to multiple (individually controlled) irradiation systems.

[0019] Furthermore, the control system is configured to control one or more of the radiation intensity and spectral distribution of horticultural radiation. The term "control" and similar terms specifically refer at least to determining the behavior of an element or monitoring the operation of an element. Therefore, "control" and similar terms as used herein can refer, for example, to applying an action to an element (determining the behavior or monitoring the operation of the element), such as, for example, measuring, displaying, actuating, turning, moving, changing temperature, etc. In addition, the term "control" and similar terms may additionally include monitoring. Therefore, the term "control" and similar terms can include applying an action.

[0020] The phrase "one or more of the radiative intensity and spectral distribution of horticultural radiation" can refer to the total spectral distribution of horticultural radiation, i.e., the power (especially visible light power) provided by the irradiation system. However, in certain embodiments, the control system can also be configured to control the spectral distribution, for example, by reducing or increasing a portion of the spectral distribution relative to other portions. Thus, in embodiments, the control system can be configured, for example, to control one or more of the intensity and spectral distribution of horticultural radiation based on signals from one or more optical sensors.

[0021] As indicated above, the control system is configured to control one or more of the radiative intensity and spectral distribution of horticultural radiation depending on canopy closure in at least a portion of the horticultural arrangement.

[0022] The controllable radiation source can be, for example, an LED radiation source, a HID radiation source, a laser radiation source, or other suitable radiation source. One or more controllable radiation sources can include means for controlled interaction with plants, such as by filtering and / or concentrating the generated radiation, and / or by modifying the flow rate of the plant, and thus modifying the interaction time with the plant. Radiation filters can be configured to selectively block radiation in one or more predetermined wavelength regions. Radiation concentrators can be configured to concentrate radiation onto the plant, for example, using a lens or mirror. Filters and concentrators can also be combined, for example, by wavelength conversion, reducing the radiation intensity of a first wavelength (filtering) while increasing the radiation intensity of a second wavelength (concentration).

[0023] One or more radiation filters may have, for example, controllable radiation filtering properties and / or controllable location. Similarly, one or more radiation concentrators may have, for example, controllable radiation concentrating properties and / or controllable location. This controllable location allows the filters and / or concentrators to be selectively inserted between the radiation source and the plant, and removed between the radiation source and the plant.

[0024] In the disclosed system for irradiating multiple plants, the first radiation formulation includes a higher far-infrared dose than the second radiation formulation. Additionally or alternatively, the first radiation formulation may include a lower blue, deep blue, and / or ultraviolet radiation dose than the second radiation formulation.

[0025] Generally, for high light utilization efficiency, the time spent closing the canopy should be as short as possible. It has been observed that this time can be shortened by adding far-red light to the spectrum. Once the canopy is closed, growth will continue, but the effect of the additional far-red light will be negligible. Therefore, after canopy closure, far-red light can be removed from the radiation formulation, reducing the energy consumption of the radiation system.

[0026] In contrast, blue and ultraviolet light tend to reduce the growth rate of plants (but can have other beneficial effects), and therefore, the first radiation formulation may include a relatively low dose of blue / UV light to promote rapid plant growth until the canopy closes.

[0027] In one embodiment, the signal indicating the state of the plant canopy is a signal indicating that the plant canopy is closed. In such an embodiment, the data processing system can be configured to determine that the plant canopy is not closed before receiving the signal, and to determine that the plant canopy is closed after receiving the signal.

[0028] Signals indicating canopy closure can be received, for example, from an image processing system that monitors plant canopies (described below), or from a user interface activated by a human operator when canopy closure is deemed to be complete. In the latter case, canopy closure can be determined visually.

[0029] In one embodiment, the system further includes an image processing system configured to receive an image representing a plant canopy formed by a plurality of plants and determine, based on the image, whether the plant canopy is closed.

[0030] Image processing systems can be integrated into data processing systems. Alternatively, image processing systems can be external to data processing systems, for example, in the form of smartphones or tablets with image processing software, or in the form of dedicated monitoring systems.

[0031] A plant canopy can be considered closed when a predetermined percentage of pixels in an image represent the plant canopy. The predetermined percentage of pixels can be at least 80%, at least 85%, at least 90%, 95%, at least 96%, at least 97%, at least 98%, at least 99%, or 100% of the pixels in the image.

[0032] Calculating the pixels representing the plant canopy is generally a relatively simple and reliable method. Plant trays or tables that typically form the background, or at least their main parts, usually have a color that contrasts with the plant canopy; for example, the tray may be configured to reflect light while the plant absorbs it. Depending on the light source activated when the image is acquired, pixels representing the plant canopy can be identified, for example, by relatively high green values ​​(reflected by the leaves) and / or relatively low red values ​​(absorbed by the leaves).

[0033] In one embodiment, a plant canopy is considered closed when a predetermined percentage of the plurality of plants are in contact with a predetermined number of neighboring plants that is at least greater than zero. For example, the predetermined number of neighboring plants could be one neighboring plant, or all neighboring plants, or all neighboring plants except one, and so on. The predetermined percentage of the plurality of plants could be, for example, at least 50%, at least 75%, at least 90%, at least 95%, at least 99%, or 100%.

[0034] In one embodiment, the system further includes a camera communicatively connected to an image processing system for acquiring images of a canopy formed by multiple plants. As an example, the camera may be mounted above multiple plants to obtain a top-down view of the canopy formed by the multiple plants.

[0035] In one embodiment, the switch from the first radiation formulation to the second radiation formulation can be delayed for a predetermined amount of time after coronal closure.

[0036] For example, the data processing system can be configured to irradiate multiple plants according to a first radiation formula during a predetermined time period after the first moment when the plant canopy is considered closed, and irradiate multiple plants according to a second radiation formula after the predetermined time period following the first moment when the plant canopy is considered closed. This can be achieved, for example, by delaying the transmission of control signals.

[0037] Alternatively, the irradiation system can be configured to switch from irradiating multiple plants according to a first radiation formula to irradiating multiple plants according to a second radiation formula after a predetermined amount of time has elapsed since the irradiation system has received the control signal.

[0038] The booking duration can be one of the following: one day, two days, three days, four days, five days, or six days or more.

[0039] After the initial conditions are met, wait a few days (e.g., approximately 1-7 days) to ensure the canopy is thick enough throughout. The optimal number of days between closing the canopy and switching light formulations can depend on the growing plant.

[0040] In one embodiment, each of the first and second radiation formulations defines one or more properties of the radiation to be provided to multiple plants for a specific time period.

[0041] The data processing system can be configured to cause the irradiation system to generate radiation such that the radiation has photon flux and / or photon flux density and / or spectral power distribution and / or irradiation timing as defined by the first and second radiation formulations, respectively.

[0042] One or more properties of radiation may include at least one of the following: - Such as the photon flux of radiation generated by the irradiation system. – Such as the photon flux density of radiation received by multiple plants, – The spectral power distribution of the radiation produced by the irradiation system, and – Timing of irradiation.

[0043] The timing of irradiation can refer to the light cycle (expressed as, for example, the number of hours per day) and / or the irradiation schedule (i.e., which hours of the day it falls within).

[0044] In such an embodiment, the data processing system can be configured to cause the irradiation system to generate radiation such that the radiation has photon flux and / or photon flux density and / or spectral power distribution and / or irradiation timing as defined by the first and second radiation formulations, respectively.

[0045] The timing of irradiation can include the temporal variation of photon flux (density) and / or spectral power distribution, and / or the duration of irradiation. Photon flux density can be expressed, for example, in µmol / (m²). 2 s) or defined by any other useful quantity.

[0046] In one aspect, this disclosure relates to a computer-implemented method for irradiating multiple plants, the method comprising: receiving a signal indicating the state of a plant canopy formed by the multiple plants; determining, based on the received signal indicating the state of the plant canopy, whether the plant canopy is closed; and sending a control signal to an irradiation system, the control signal being based on the determined canopy closure. The control signal may configure the irradiation system to switch from irradiating the multiple plants according to a first radiation formula to irradiating the multiple plants according to a second radiation formula different from the first radiation formula.

[0047] Specifically, if the plant canopy is not closed, the control signal can cause the irradiation system to irradiate multiple plants according to the first radiation formula; if the plant canopy is closed, the control signal can cause the irradiation system to irradiate multiple plants according to the second radiation formula.

[0048] Therefore, this method can be used to control the system described above. This method can be executed, for example, by the data processing system described above.

[0049] One aspect of this disclosure relates to a computer including a computer-readable storage medium embodying computer-readable program code, and a processor (preferably a microprocessor) coupled to the computer-readable storage medium, wherein the processor is configured to perform any of the methods disclosed herein in response to executing the computer-readable program code.

[0050] One aspect of this disclosure relates to a computer program or computer program suite that includes at least one software code portion or a computer program product storing at least one software code portion, the software code portion being configured to perform any of the methods disclosed herein when run on a computer system.

[0051] One aspect of this disclosure relates to a non-transitory computer-readable storage medium storing at least one portion of software code that, when executed or processed by a computer, is configured to perform any of the methods disclosed herein.

[0052] As those skilled in the art will appreciate, aspects of the present invention can be embodied as systems, methods, or computer program products. Therefore, aspects of the present invention can take the form of entirely hardware embodiments, entirely software embodiments (including firmware, resident software, microcode, etc.), or embodiments combining software and hardware aspects, which are generally referred to herein as “circuit,” “module,” or “system.” The functionality described in this disclosure can be implemented as algorithms executed by a computer’s processor / microprocessor. Furthermore, aspects of the present invention can take the form of computer program products embodied in one or more computer-readable media having computer-readable program code embodied thereon (e.g., stored thereon).

[0053] Any combination of one or more computer-readable media can be used. A computer-readable medium can be a computer-readable signal medium or a computer-readable storage medium. A computer-readable storage medium can be, for example, but not limited to, electronic, magnetic, optical, electromagnetic, infrared, or semiconductor systems, apparatuses, or devices, or any suitable combination thereof. More specific examples of computer-readable storage media may include, but are not limited to, electrical connections having one or more wires, portable computer disks, hard disks, random access memory (RAM), read-only memory (ROM), erasable programmable read-only memory (EPROM or flash memory), optical fiber, portable compact disk read-only memory (CD-ROM), optical storage devices, magnetic storage devices, or any suitable combination thereof. In the context of this invention, a computer-readable storage medium can be any tangible medium that can contain or store a program used by or in conjunction with an instruction execution system, apparatus, or device.

[0054] Computer-readable signal media may include propagated data signals having computer-readable program code embodied therein (e.g., in baseband or as part of a carrier wave). Such propagated signals may take any of a variety of forms, including, but not limited to, electromagnetic, optical, or any suitable combination thereof. A computer-readable signal medium may be any computer-readable medium that is not a computer-readable storage medium and may convey, propagate, or deliver a program used by or in conjunction with an instruction execution system, apparatus, or device.

[0055] Program code embodied on a computer-readable medium can be transmitted using any suitable medium (including, but not limited to, wireless, wired, fiber optic, cable, RF, etc., or any suitable combination thereof). Computer program code for carrying out the operations of various aspects of the invention can be written in any combination of one or more programming languages, including object-oriented programming languages ​​(such as Java). TM Programming languages ​​include Smalltalk, C++, and conventional procedural programming languages ​​(such as the "C" programming language or similar programming languages). Program code can execute entirely on the user's computer, partially on the user's computer, as a standalone software package, partially on the user's computer and partially on a remote computer, or entirely on a remote computer or server. In the latter scenario, the remote computer can be connected to the user's computer via any type of network, including a local area network (LAN) or a wide area network (WAN), or can connect to an external computer (e.g., via the internet through an internet service provider).

[0056] The aspects of the invention are described below with reference to flowchart illustrations and / or block diagrams of methods, apparatus (systems), and computer program products claimed in embodiments of the invention. It will be understood that each block of the flowchart illustrations and / or block diagrams, and combinations of blocks in the flowchart illustrations and / or block diagrams, can be implemented by computer program instructions. These computer program instructions can be provided to the processor (particularly a microprocessor or central processing unit (CPU)) of a general-purpose computer, special-purpose computer, or other programmable data processing apparatus to produce a machine, such that the instructions, executable via the processor of the computer, other programmable data processing apparatus, or other device, create means for implementing the functions / actions specified in the flowchart illustrations and / or one or more block diagram blocks.

[0057] These computer program instructions may also be stored in a computer-readable medium that can instruct a computer, other programmable data processing apparatus, or other device to operate in a particular manner, causing the instructions stored in the computer-readable medium to produce an article of writing, which includes instructions that implement the functions / actions specified in flowcharts and / or one or more block diagrams.

[0058] Computer program instructions may also be loaded onto a computer, other programmable data processing apparatus, or other device to cause a series of operational steps to be performed on the computer, other programmable apparatus, or other device to produce a computer-implemented process, such that the instructions, which execute on the computer or other programmable apparatus, provide for implementing the functions / actions specified in the flowchart and / or one or more block diagram boxes.

[0059] The flowcharts in the figures illustrate the architecture, functionality, and operation of possible implementations of the systems, methods, and computer program products claimed in various embodiments of the invention. In this regard, each block in the flowchart or block diagram may represent a module, segment, or portion of code, comprising one or more executable instructions for implementing the specified logical function(s). It should also be noted that in some alternative implementations, the functions mentioned in the blocks may not appear in the order shown in the figures. For example, two blocks shown consecutively may actually be executed substantially simultaneously, or sometimes these blocks may be executed in reverse order, depending on the functions involved. It will also be noted that each block in the block diagram and / or flowchart, and combinations of blocks in the block diagram and / or flowchart, may be implemented by a system based on dedicated hardware, or a combination of dedicated hardware and computer instructions, that performs the specified function or action.

[0060] In addition, a computer program for carrying out the methods described herein is provided, as well as a non-transitory computer-readable storage medium for storing the computer program. The computer program may, for example, be downloaded (updated) to an existing system (e.g., an existing control system), or stored during the manufacture of such systems.

[0061] Unless otherwise explicitly stated, elements and aspects discussed with respect to a particular embodiment or with respect to a particular embodiment may be suitably combined with elements and aspects of other embodiments. Embodiments of the invention will be further described with reference to the accompanying drawings, which schematically illustrate embodiments as claimed in the invention. It will be understood that the invention is not limited in any way to these specific embodiments. Attached Figure Description

[0062] Various aspects of the invention will be explained in more detail with reference to the exemplary embodiments shown in the accompanying drawings, in which: Figure 1 A system for irradiating multiple plants according to an embodiment is schematically illustrated; Figures 2A-2D The diagram schematically illustrates a canopy formed by multiple plants at various stages of closure; and Figure 2E and Figure 2F Images of a canopy formed by multiple plants at various stages of closure are shown; Figure 3A and Figure 3B This is a flowchart illustrating an embodiment of the method; Figure 4 This is a graph showing the effect of the spectrum on the shelf life of wild rocket; and Figure 5 The figure illustrates a data processing system according to an embodiment. Detailed Implementation

[0063] In the accompanying drawings, the same reference numerals indicate the same or similar elements.

[0064] Currently, in vertical agriculture, radiation formulations are specifically optimized for each crop and remain constant throughout the growing season, particularly for food production. However, there is ample evidence that plants can benefit from different light treatments depending on their growth stage.

[0065] For example, it is known that adding far-infrared (FR, typically about 730 nm) illumination to the standard red and blue (RB, typically about 660 nm and about 450 nm, respectively) light induces leaf extension for the growth of vegetables such as lettuce and similar leafy vegetables. With this increase in leaf area, more light can be intercepted, leading to faster biomass production. However, this increase in far-infrared radiation in the spectrum can lead to a decline in plant quality in terms of morphology, pigment concentration, and shelf life. A higher dose of blue, compared to far-infrared, will have the exact opposite effect on morphology: it significantly reduces final fresh weight, makes plants more compact, and can reduce the number of leaves per plant or canopy area, but can lead to improved quality, pigment concentration, and shelf life.

[0066] Therefore, a radiation formulation has been created that begins with a spectrum having a relatively large amount of red and / or far-red light and a relatively small amount of blue, deep blue, or ultraviolet light. Then, in the final days before harvest, the spectrum is altered to a so-called pre-harvest spectrum, which includes additional blue, deep blue, and / or ultraviolet light and less or no far-red light, to improve crop quality, for example, to produce natural color, increase vitamin C content, or reduce nitrate content.

[0067] Not only can plant quality benefit from radiation formulations tailored to these plant stages, but light use efficiency (LUE, typically expressed as grams of crop harvested per mole of photons) can also be improved. Dimmable and color-controlled luminaires have recently become available, offering the possibility of further improving LUE while balancing plant yield and quality by providing radiation formulations based on plant growth stages.

[0068] Figure 1 A system for irradiating multiple plants according to a first embodiment is schematically illustrated. System 1 includes an irradiation system 3 configured to irradiate multiple plants 11. The irradiation system includes multiple controllable radiation sources 5. The controllable radiation sources may include, for example, multiple individually controllable or grouped controllable LEDs. In this example, the radiation sources 5 are controlled by a controller 7. The radiation sources may be configured to provide, for example, growth or horticultural radiation. The controller may control one or more of the radiation intensity and spectral distribution of the horticultural radiation.

[0069] System 1 also includes a data processing system 100 communicatively connected to the irradiation system 3. This data processing system includes a processor, an input interface, and an output interface. The input and output interfaces can be combined in a single I / O interface (e.g., a (general-purpose) communication interface). Specifically, the data processing system can be configured to generate control signals and transmit these control signals via the output interface to a controller 7, which can be configured to receive the control signals and control the radiation source 5 accordingly. (Refer to below...) Figure 5 Examples of data processing systems are described in more detail.

[0070] Data processing system 100 is configured to receive or determine whether a plant canopy formed by a plurality of plants 11 is closed. For example, data processing may be configured to receive a signal indicating the state of a plant canopy formed by a plurality of plants 11, and determine whether the plant canopy is closed based on the received signal indicating the state of the plant canopy. A canopy may be defined as an area covered by a plurality of plants, or more specifically, an area covered by the photosynthetically active parts of the plants (such as leaves). In the depicted embodiment, data processing system 100 receives parameters representing the canopy state from image processing system 9. In some embodiments, image processing system 9 may be part of data processing system 100. The canopy state may be binary (e.g., open / closed) or multi-valued (e.g., relative areas covered by the canopy). Examples of canopy states are discussed in more detail below with reference to FIG2.

[0071] The data processing system 100 is also configured to cause the irradiation system 3 to irradiate multiple plants based on canopy status, particularly based on whether the canopy formed by the multiple plants 11 is considered closed. For example, based on canopy closure, the data processing system 100 can cause the irradiation system 3 to switch from a first radiation formulation to a second radiation formulation different from the first. In a typical example, the first radiation formulation is optimized for growth, particularly lateral growth. The first radiation formulation may include a relatively large amount of red light and / or far-infrared radiation. The second radiation formulation can be optimized for different parameters; generally, a radiation formulation optimized for rapid growth results in suboptimal characteristics of the plants in other aspects, such as shelf life, the presence and / or concentration of valuable assimilates (such as vitamins, alkaloids, etc.), plant health, etc. In some cases, the second radiation formulation includes a larger amount of blue light radiation, deep blue light radiation, and / or ultraviolet radiation and / or a smaller amount of far-infrared radiation compared to the first radiation formulation. The timing of the switch from the first radiation formulation to the second radiation formulation depends on the canopy closure of the multiple plants. The switching time can be essentially immediately after the canopy is considered closed, or there can be some delay, such as one, two, three, four, five, or six or more days after the canopy is first considered closed.

[0072] Note that the irradiation system does not need to switch from the first radiation formulation to the second radiation formulation simultaneously. For example, if only a portion of the canopy is considered closed, only the irradiation source irradiating that portion of the canopy can switch to the second radiation formulation, while the irradiation source irradiating the non-closed portions of the canopy continues to irradiate according to the first radiation formulation.

[0073] Therefore, System 1 can be configured to improve light utilization efficiency by promoting growth (especially lateral growth) when the canopy is not closed, so as to maximize light absorption by multiple plants 11. Once the canopy is substantially closed, different optimized radiation formulations can be used.

[0074] The irradiation system 3 may include at least one radiation source 5. In a typical embodiment, the irradiation system includes multiple radiation sources 5 for generating artificial radiation, typically controllable radiation sources such as LEDs. Additionally or alternatively, the irradiation system 3 may include one or more controllable radiation filters and / or radiation concentrators. Such filters and / or concentrators can be used, for example, to control aspects of the artificially generated radiation spectrum that cannot be adequately controlled by the radiation sources.

[0075] The irradiation system may further include a controller 7. The controller 7 may include a processor and a memory communicatively coupled to the processor. The irradiation system 3 may include an interface enabling communication with the data processing system 100. The irradiation system 3 may be configured to apply at least a first irradiation formulation and a second irradiation formulation to a plurality of plants 11.

[0076] The controlled radiation source can be, for example, an LED radiation source, an HID radiation source, or other suitable radiation source. One or more controlled radiation sources can include radiation sources that have controlled interactions with the plant (e.g., through filtering and / or concentrating natural radiation). In some embodiments, the plant grows in or on a tray that is movable relative to the radiation source; in such a system, the interaction can be controlled (additionally or alternatively) by modifying the plant's movement speed and thus the interaction time. Alternatively, in such a system, the radiation formula can "move" with the tray (while the radiation source does not move) by having a data processing system or controller adjust the localized radiation formula based on the movement of the tray.

[0077] Radiation filters can be configured to selectively block radiation from one or more predetermined wavelength regions, either partially or completely. Radiation concentrators can be configured, for example, to concentrate radiation onto plants using lenses or mirrors. Filters and concentrators can also be combined, for example, by wavelength conversion, to reduce the intensity of radiation at a first wavelength (filtering) while increasing the intensity of radiation at a second wavelength (concentration).

[0078] For example, it is known that far-infrared radiation can increase growth rate for various crops, but generally also reduces crop quality, while a high blue spectrum is known to keep plants more compact (i.e., reduce growth rate) and increase antioxidant concentrations, for example, in leaves. Increased antioxidant concentrations can potentially lead to improved shelf life.

[0079] Generally, at least two growth stages can be distinguished. In the first growth stage of leafy vegetables, growth can be accelerated when a first radiation formulation is applied. The first radiation formulation typically includes a relatively large or at least non-zero amount of far-infrared radiation. In the second stage, crop quality is prioritized. Therefore, the second radiation formulation typically includes a relatively large or at least non-zero amount of blue and / or ultraviolet radiation. Depending on the circumstances, additional pre-harvest treatments may be used, which can be optimized from, for example, the perspective of light use efficiency and / or crop quality.

[0080] Note that in some cases, more than two or three different radiation formulations may be used, depending on the plant's developmental stage.

[0081] Figures 2A-2D The diagram schematically illustrates a canopy formed by multiple plants at various stages of closure. For comparison, Figure 2E and Figure 2F Images of the actual canopy formed by multiple plants at various closing stages are shown.

[0082] Figures 2A-2D A schematic top view of a (low-density) plant tray 21 comprising multiple plants 11 at consecutive moments is shown. The current example shows plants arranged in a square grid, but other arrangements are possible, such as a triangular grid. Obviously, actual plants are not perfectly circular as shown here, but many crops do grow in an approximately circular manner (as seen from above), making this a reasonable approximation. Similarly, the actual sizes of the plants are not exactly the same, as shown here, but since they are typically grown in batches under substantially the same conditions, the plants generally have roughly the same size. These figures can represent, for example, camera images obtained by a camera mounted above the plant tray. The plant tray may extend beyond the camera's field of view in one or more directions, and the canopy visible within the camera's field of view can be considered to represent the canopy of multiple plants.

[0083] Figure 2A This shows a case where the canopy is not closed. There is absolutely no contact between these plants, and only slightly more than half (about 53%) of the area is covered by the plant canopy.

[0084] exist Figure 2B In this diagram, the plants are just beginning to contact each other. In some embodiments, this can be considered canopy closure. In this illustration, all the plants are the same size, and they all begin to contact all their neighbors simultaneously. In reality, there will be some variation due to differences in the size and shape of individual plants. Therefore, in some embodiments, the canopy can be considered closed if at least a predetermined share of the neighbors are in contact.

[0085] In a simplified embodiment, the area covered by the canopy can be obtained by segmenting the image into canopy pixels and other pixels, and counting the canopy pixels. If the number of pixels representing the canopy (i.e., canopy pixels) is higher than a predetermined threshold, the canopy can be considered closed, and if the fraction is lower than the threshold, the canopy can be considered open. The threshold at which the canopy is considered closed may depend on the geometry of the plant tray. For example, suppose... Figure 2B In the circular plants, the moment when adjacent plants begin to touch each other corresponds to approximately 79% of the canopy area in the square grid and approximately 91% of the area in the triangular grid. Therefore, for the square grid, the threshold can be selected as, for example, 79%, 80%, 85%, or any intermediate value, or for the triangular grid, the threshold can be selected as, for example, 90%, 91%, 95%, or any intermediate value.

[0086] exist Figure 2C By this time, the plants have grown further and cover approximately 96% of the area. Although a portion of the tray (about 4% of the area) is not yet covered by the plant canopy, adjacent plants may begin to negatively affect each other; for example, one plant may partially shade the leaves of an adjacent plant. Therefore, in general, a balance can be sought between light utilization efficiency (which is maximized in principle if the entire plant tray is covered by the canopy, as all light can be absorbed by the plant in this case) and photosynthetic efficiency (which is maximized in principle if the plant is not shaded by, for example, its neighbors).

[0087] Therefore, a predetermined threshold can be determined based on the balance between zonal cover and adjacent plant cover. This balance may again depend on the geometry of the plant tray. The threshold can be determined, for example, 90%, 95%, 96%, 97%, 98%, or 99%.

[0088] Figure 2D The diagram shows a completely closed canopy, where 100% of the area is covered by the plant canopy. Assuming circular plants, this corresponds to approximately 36% overlap for a square grid arrangement and approximately 17% overlap for a triangular grid arrangement.

[0089] As mentioned, this overlap can be determined using a camera (e.g., a camera mounted above the plant tray). However, different methods are also possible for determining overlap, such as: manual inspection, monitoring using mobile devices (e.g., smartphones or tablets), sensors in the plant tray, light sensors that measure the intensity of light reflected from the plant tray, etc. Existing software can be used to determine canopy coverage, such as the Easy Leaf Area app installed on smartphones.

[0090] For example, canopy region scores can be obtained by analyzing the percentage of green pixels (assuming a white light source) relative to the total number of pixels in an image, or pixels with low red pixel values, using image processing software. This can be done manually by the user or automatically. Alternatively, machine learning algorithms such as Mask R-CNN can be used.

[0091] Figure 2E and Figure 2F Images of a canopy formed by multiple plants at various stages of closure are shown. Although Figure 2E The small plants in the tray (shortly after being transferred to a low-density tray) had irregular shapes, but Figure 2F Larger plants in the text have an approximately circular circumference, as indicated by the dashed circle.

[0092] Figure 3A This is a flowchart illustrating an embodiment of a method for irradiating multiple plants. The method can be performed by the system described above. Step 31 involves irradiating the multiple plants according to a first radiation formulation. Irradiation can be performed using a controlled irradiation system as described above. The first radiation formulation can be optimized for rapid plant growth and / or light utilization efficiency. In a typical example, the first radiation formulation includes a relatively large amount of red and / or far-red light, and a relatively small amount of blue, deep blue, or ultraviolet light. For example, the amount of red radiation can be 80% or more, or even 85% or more. The amount of far-infrared radiation can be at least 6%, typically between 6-12%. Increasing far-infrared radiation can increase fresh weight, but typically does not further increase light utilization efficiency.

[0093] Step 33 includes receiving a signal indicating the state of the plant canopy formed by the multiple plants. Step 35 includes determining whether the canopy layer formed by the multiple plants is closed. This step may include, for example, comparing a canopy region fraction with a predetermined threshold. Steps 33 and 35 are typically performed by a data processing system as described above.

[0094] If the canopy is not considered closed, the irradiation system continues to irradiate the 31 plants according to the first radiation formulation. Typically, steps 33 and 35 will be repeated periodically until the canopy is closed. In some embodiments, a signal is only received when the canopy is considered closed. In such embodiments, step 35 will always be evaluated as "yes". In other embodiments, several signals may be received (at different times). As described in more detail elsewhere, the signal received in step 33 may also be, for example, an image of the canopy to be analyzed by a data processing system to determine whether the canopy is considered closed. In such embodiments, steps 33 and 35 are typically repeated multiple times.

[0095] Optional step 37 includes irradiating multiple plants according to the first radiation formula for a predetermined amount of time following the initial moment when the plant canopy is considered closed. The predetermined amount of time can be one of the following: one day, two days, three days, four days, five days, or six or more days. Waiting a few days (e.g., approximately 1-7 days) after the canopy is initially considered closed ensures that the canopy is sufficiently thick throughout. The optimal number of days between canopy closure and switching the light formula may depend on the growing plants.

[0096] If the comparison indicates that the canopy is considered closed, and optional step 37 has been performed as applicable, then step 39 includes irradiating multiple plants with a second radiation formulation different from the first radiation formulation. For example, the second radiation formulation can be optimized for plant quality, such as increasing the shelf life of multiple plants or parts thereof.

[0097] Figure 3B It is a diagram and Figure 3A The flowcharts for essentially the same embodiments are shown, except that the method can be performed entirely by a data processing system. Steps 33 and 35 can be performed as described above. Figure 3A As described.

[0098] Furthermore, step 32 includes configuring the controlled irradiation system to irradiate multiple plants according to a first radiation formula, and step 38 includes configuring the controlled irradiation system to irradiate multiple plants according to a second radiation formula. For example, a data processing system may generate a control signal and transmit the control signal to the controlled irradiation system. Although not shown, this embodiment may include an optional waiting step similar to step 37, during which the controlled irradiation system is configured to, or remains configured to, irradiate multiple plants according to the first radiation formula.

[0099] Therefore, when the canopy closes, the plants largely or completely cover the surface area of ​​the growing platform, meaning the plant canopy covers a significant portion of the plant support. "A significant portion" can refer to at least 80% of the total plant support, or at least 85%, 90%, 95%, 96%, 97%, 98%, 99%, or 100% of the total plant support. At that point, the far-infrared portion of the spectrum can be switched off and eventually replaced by blue light. The calculated plant surface cover results can be recorded by continuously monitoring growth and used as input to control systems such as the GrowWise Control System (GWCS). The GrowWise Control System is Signify's radiation control system that schedules radiation according to a user-defined radiation recipe.

[0100] In one embodiment, the control system acquires and analyzes camera images. The definition of a closed canopy, based on user input or default values, can be part of the light recipe. An example of such a definition is that the canopy is considered "closed" when the plant's surface area covers at least 95% of the surface area of ​​the growth platform. Another definition is that the canopy is considered closed one day after the plant's surface area reaches 100% of the surface area of ​​the growth platform. Other examples are given elsewhere in this disclosure.

[0101] According to the current definition, at the first moment of canopy closure, the control system shuts off far-infrared radiation. Alternatively, far-infrared radiation is significantly reduced, for example, by at least two times.

[0102] In an alternative embodiment, the image processing system is equipped with edge computing capabilities to generate a "canopy closure" signal sent to the control system. Upon receiving the "canopy closure" signal from one or more or most cameras, far-infrared radiation can be switched off or reduced. Alternatively, the spectrum can be locally switched; for example, for each light source, the spectrum is determined based on coverage area determined from images from the camera closest to that light source. Other alternatives will be readily apparent to those skilled in the art.

[0103] Having automatic feedback input to the control system to organize the timing of switching radiation settings is beneficial because growth rate is highly dependent on species, variety, and climate settings. Another advantage of automatic growth rate monitoring involves the fact that the timing of canopy closure becomes predictable if other growth parameters remain unchanged during this period. This makes further optimization regarding light use efficiency (LUE) easier to implement in vertical farm systems. Furthermore, canopy closure time can serve as a predictor for optimal harvest time.

[0104] Figure 4 This is a graph showing the effect of the spectrum on the shelf life of wild arugula. The graph is from the version by Anpo et al. Plant Factory using Artificial Lighting (Elsevier 2019) pp. 33-43, Nicole et al., 'Chapter 1.4: Postharvest quality of leafy greens growing in a plantfactory', which is incorporated herein by reference.

[0105] Figure 4 The results show the results for three different spectra relative to 4 oOverall visual quality (OVQ) for the number of days stored under C: red-white (RW, triangle), red-blue (RB, rhombus), and red-white-far-red (RWFr, circle). Overall visual quality crossed the consumer acceptance line (OVQ = 6) at 24, 26, and 20 days, respectively. Each data point is the average of the overall visual quality for three individual samples. Plants were grown under the corresponding spectrum for the entire crop cycle, from seedling to harvest.

[0106] Therefore, compared to the red-white reference spectrum, increasing far-red light shortens shelf life. This indicates that plant quality (in this case, shelf life) can be improved by using a second radiative formulation that contains no far-red light or only a small amount of far-red light (after canopy closure). Meanwhile, a first radiative formulation containing a relatively large amount of far-red light (before canopy closure) improves light use efficiency by stimulating plant growth.

[0107] For example, it is known that adding far-red (FR) illumination to the standard red-blue (RB) spectrum induces leaf extension for the growth of lettuce and similar leafy vegetables. With this increase in leaf area, more light is blocked, leading to faster biomass production. However, as... Figure 4 As shown, this increase in far-infrared radiation in the spectrum leads to a decline in plant quality in terms of morphology, pigment concentration, and shelf life. Higher doses of blue, compared to far-infrared, generally have the opposite effect on morphology. It significantly reduces final fresh weight, makes plants more compact, and can reduce the number of leaves per plant or canopy area.

[0108] Figure 5 A block diagram illustrating a data processing system as claimed in the embodiments is depicted.

[0109] like Figure 5 As shown, the data processing system 100 may include at least one processor 102 coupled to a memory element 104 via a system bus 106. Thus, the data processing system can store program code within the memory element 104. Furthermore, the processor 102 can execute program code accessed from the memory element 104 via the system bus 106. In one aspect, the data processing system may be implemented as a computer suitable for storing and / or executing program code. However, it should be understood that the data processing system 100 may be implemented in the form of any system including a processor and memory, capable of performing the functions described herein.

[0110] Memory element 104 may include one or more physical memory devices, such as, for example, local memory 108 and one or more mass storage devices 110. Local memory may refer to random access memory or (multiple) other non-persistent memory devices generally used during the actual execution of the program code. Mass storage devices may be implemented as hard disk drives or other persistent data storage devices. Processing system 100 may also include one or more cache memories (not shown) that provide temporary storage for at least some of the program code to reduce the number of times the program code must be retrieved from mass storage device 110 during execution.

[0111] Optionally, the input / output (I / O) devices, depicted as input device 112 and output device 114, may be coupled to the data processing system. Examples of input devices may include, but are not limited to, a keyboard, a pointing device such as a mouse, a touch-sensitive display, an external control system as mentioned herein, or the like. Examples of output devices may include, but are not limited to, a monitor or display, a speaker, an LED driver, or the like. The input and / or output devices may be coupled to the data processing system directly or via an intermediate I / O controller.

[0112] In embodiments, the input and output devices may be implemented as a combined input / output device (in... Figure 5 (Dashed lines are used to illustrate input device 112 and output device 114). An example of such a combined device is a touch-sensitive display, sometimes also called a "touchscreen display" or simply a "touchscreen". In such embodiments, input to the device can be provided by the movement of a physical object, such as, for example, a stylus or a user's finger, on or near the touchscreen display.

[0113] Network adapter 116 can also be coupled to the data processing system to enable it to couple to other systems, computer systems, remote network devices, and / or remote storage devices via an intermediate private or public network. The network adapter may include a data receiver for receiving data transmitted to the data processing system 100 from the systems, devices, and / or networks, and a data transmitter for transmitting data from the data processing system 100 to the systems, devices, and / or networks. Modems, cable modems, and Ethernet cards are examples of different types of network adapters that can be used with the data processing system 100.

[0114] like Figure 5As illustrated, memory element 104 can store application program 118. In various embodiments, application program 118 may be stored in local memory 108, one or more mass storage devices 110, or separated from both local memory and mass storage devices. It should be understood that data processing system 100 may further execute an operating system (…). Figure 5 (Not shown in the image), the operating system can facilitate the execution of application 118. Application 118, implemented in the form of executable program code, can be executed by data processing system 100 (e.g., by processor 102). In response to executing the application, data processing system 100 can be configured to perform one or more operational or method steps described herein.

[0115] In one aspect of the invention, the data processing system 100 may represent a control system for an LED driver as described herein.

[0116] In another aspect, data processing system 100 may represent a client data processing system. In that case, application 118 may represent a client application that, when executed, configures data processing system 100 to perform the various functions described herein with reference to "client". Examples of clients may include, but are not limited to, personal computers, laptops, mobile phones, etc.

[0117] On the other hand, the data processing system 100 can represent a server. For example, the data processing system can represent an (HTTP) server, in which case the application 118 can be configured to perform (HTTP) server operations when executed.

[0118] Various embodiments of the present invention can be implemented as a program product for use with a computer system, wherein the program(s) of the program product define the functionality of the embodiments (including the methods described herein). In one embodiment, the program(s) may be contained on a variety of non-transitory computer-readable storage media, wherein, as used herein, the expression “non-transitory computer-readable storage media” includes all computer-readable media, with the sole exception of transient propagation signals. In another embodiment, the program(s) may be contained on a variety of transient computer-readable storage media. Illustrative computer-readable storage media include, but are not limited to: (i) non-writable storage media on which information is permanently stored (e.g., read-only memory devices within a computer, such as CD-ROM discs readable by a CD-ROM drive, ROM chips, or any type of solid-state non-volatile semiconductor memory); and (ii) writable storage media on which changeable information is stored (e.g., flash memory, floppy disks within a floppy disk drive or hard disk drive, or any type of solid-state random access semiconductor memory). The computer program may run on the processor 102 described herein.

[0119] The terminology used herein is for the purpose of describing particular embodiments only and is not intended to limit the invention. As used herein, the singular forms “a,” “an,” and “the” are intended to include the plural forms as well, unless the context clearly indicates otherwise. It will be further understood that, when used in this specification, the terms “comprising” and / or “including” specify the presence of the stated features, integers, steps, operations, elements, and / or components, but do not exclude the presence or addition of one or more other features, integers, steps, operations, elements, components, and / or groups thereof.

[0120] All the means or steps plus functional elements in the following claims are intended to include any structure, material, action, and equivalent for performing a function in combination with other claimed elements as specifically claimed. Descriptions of embodiments of the invention have been shown for illustrative purposes, but are not intended to be exhaustive or limited to the embodiments in the disclosed forms. Many modifications and variations will be apparent to those skilled in the art without departing from the scope and spirit of the invention. Embodiments have been chosen and described in order to best explain the principles of the invention and some practical applications, and to enable others skilled in the art to understand the invention with respect to various embodiments with various modifications suitable for particular intended uses.

Claims

1. A system (1) for irradiating a plurality of plants (11) on a plant support (21), said system (1) comprising: An irradiation system (3) is configured to irradiate multiple plants (11) with radiation having one or more controllable radiation properties. and A data processing system (100) includes an input interface (116) for receiving signals indicating the state of the plant canopy, an output interface (116) for sending control signals to the irradiation system (3), and a processor (102) configured to: - Receive signals indicating the state of the plant canopy formed by multiple plants (11); - Determine whether the plant canopy is closed based on received signals indicating the state of the plant canopy; wherein the plant canopy is closed when it covers a considerable portion of the plant support (21), and - Send a control signal to the irradiation system (3), the control signal being determined to be closed based on the canopy; The irradiation system (3) is configured to switch from irradiating multiple plants (11) according to a first radiation formula to irradiating multiple plants (11) according to a second radiation formula different from the first radiation formula based on the received control signal. The first radiation formulation includes a higher far-infrared dose than the second radiation formulation, and / or the first radiation formulation includes a lower blue, deep blue, and / or ultraviolet radiation dose than the second radiation formulation.

2. The system according to claim 1, The signals indicating the state of the plant canopy include those indicating canopy closure, and... The processor (102) is configured to determine that the plant canopy is not closed before receiving the signal, and to determine that the plant canopy is closed after receiving the signal.

3. The system according to any one of the preceding claims further includes an image processing system configured to: Receive an image representing a plant canopy formed by the plurality of plants; Determine the state of the plant canopy based on the image; and Send a signal indicating the state of the plant canopy to the data processing system (100).

4. The system of claim 3, wherein the state of the plant canopy is based on the absolute or relative number of pixels in an image representing the plant canopy, and wherein determining canopy closure includes determining that at least a predetermined absolute or relative number of pixels in the image represent the plant canopy.

5. The system of claim 4, wherein the predetermined number is a relative number equal to at least 80%, at least 85%, at least 90%, at least 95%, at least 96%, at least 97%, at least 98%, at least 99%, or 100% of the pixels in the image.

6. The system according to any one of claims 1-3, wherein the state of the plant canopy is based on the absolute or relative number of one or more of its corresponding neighboring plants, and wherein determining that the plant canopy is closed includes determining that the absolute or relative number of one or more of its corresponding neighboring plants is at least equal to a predetermined threshold.

7. The system according to any one of claims 3-6, further comprising a camera communicatively connected to an image processing system for acquiring an image of the plant canopy formed by the plurality of plants.

8. The system of claim 7, wherein the camera is located above the plurality of plants; and / or The camera is integrated into the image processing system, and the image processing system is located above the plurality of plants; and / or The camera is integrated into the illumination system.

9. The system according to any one of the preceding claims, wherein the processor (102) is configured to send the control signal to the irradiation system (3) after a predetermined amount of time following the determination of the first moment of plant canopy closure; or The irradiation system (3) is configured to switch from irradiating the plurality of plants (11) according to the first radiation formula to irradiating the plurality of plants (11) according to the second radiation formula after a predetermined amount of time has elapsed since the irradiation system has received the control signal.

10. The system of claim 9, wherein the predetermined time is one of the following: one day, two days, three days, four days, five days, or six or more days.

11. The system according to any one of the preceding claims, wherein Each of the first and second radiation formulations defines one or more radiation properties to be provided to a plurality of plants for a specific time period, wherein said one or more radiation properties include at least one of the following: - Such as the photon flux of radiation generated by the irradiation system. - Such as the photon flux density of radiation received by multiple plants, - The spectral power distribution of the radiation produced by the irradiation system, and - The timing of the irradiation; and The data processing system is configured to cause the irradiation system to generate radiation such that the radiation has photon flux and / or photon flux density and / or spectral power distribution and / or irradiation timing as defined by the first irradiation formulation and the second irradiation formulation, respectively.

12. A computer-implemented method for irradiating a plurality of plants (11) on a plant support (21), the method comprising: - Receive signals indicating the state of the plant canopy formed by multiple plants (11); - Determine whether the plant canopy is closed based on the received signals indicating the state of the plant canopy, wherein the plant canopy is closed when it covers a considerable portion of the plant support (21); as well as - Send a control signal to the irradiation system (3), the control signal being based on the determined canopy closure, the control signal configuring the irradiation system to switch from irradiating multiple plants (11) according to a first radiation formula to irradiating multiple plants (11) according to a second radiation formula different from the first radiation formula. The first radiation formulation includes a higher far-infrared dose than the second radiation formulation, and / or the first radiation formulation includes a lower blue, dark blue, and / or ultraviolet radiation dose than the second radiation formulation.

13. A computer program comprising instructions that, when executed by a data processing system of a system as claimed in any one of claims 1 to 11, cause the system to perform the method as claimed in claim 12.

14. A computer-readable storage medium having a computer program as described in claim 13 stored thereon.

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