Adjusting fruit setting of pepper by dynamically adjusting LED illumination spectrum

Abstract

The present invention provides a system (1000) for culturing a pepper plant (10), where the system (1000) comprises a light generating device (100) configured to provide device light (101) to the pepper plant (10), where the device light (101) comprises one or more of red light and far-red light, where the red light comprises one or more wavelengths in the range of 600-700 nm, and a control system (300), where the device light (101) comprises one or more wavelengths in the range of 600-700 nm, where the far-red light comprises one or more wavelengths in the range of 600-700 nm, and where the far-red light comprises one or more wavelengths in the range of 600-700 nm. And wherein the far-red light comprises one or more wavelengths in the range of 700-800 nm wherein the system (1000) has an operable mode wherein: the control system (300) is configured to acquire an input signal wherein the input signal is related to a plant load related parameter of the pepper plant (10), wherein the plant load related parameters are selected from the group comprising plant load, flowering rate, flower abortion rate, fruit setting rate and fruit abortion rate; the control system (300) is configured to determine a plant load based on the input signal, and wherein one or more of: (i) the control system (300) is configured to compare the plant load to a lower plant load threshold, and if the plant load is below the lower plant load threshold, from gt; a target R: FR ratio of red to far-red light is selected in the range of 15; and (ii) the control system (300) is configured to compare the plant load to a higher plant load threshold, and if the plant load is above the higher plant load threshold, from lt; selecting a target R: FR ratio in the range of 15; the control system (300) is configured to expose the pepper plant (10) to a target R: FR ratio by controlling the light generating device (100).

Description

Technical Field

[0001] The present invention relates to a system for cultivating plants. Furthermore, the present invention relates to a horticultural system comprising such a system. However, the present invention also relates to a method for cultivating plants. Background Art

[0002] Plant growth lighting devices and systems are known in the art. For example, US9854749 describes a system for plant growth, the system comprising: a first LED device configured to emit light of a first color, wherein the first LED device is configured to emit light having a controlled beam half angle of less than or equal to 60°; and a second LED device configured to emit light of a second color, wherein the second LED device is configured to emit light at a controlled beam half angle of less than or equal to 60°; and wherein the system is configured to produce an emission spectrum having a first emission peak below 500nm and a second emission peak above 600nm. The first emission peak is at 425-475nm, and the second emission peak is at 635-685nm. In addition, the system is configured to have a third emission peak at 500-600nm. The photon flux of the emission spectrum contains between 5% and 10% green light.

[0003] US2021 / 0112727 A1 discloses a method for controlling bolting using high levels of far-infrared. The disclosed method comprises providing a first horticultural light to the plant during a control mode, wherein at least 15% of the photons of the first horticultural light have a wavelength selected from the range of 700-800 nm, wherein at least 45% of the photons of the first horticultural light have a wavelength selected from the range of 640-700 nm, and wherein at most 10% of the photons of the first horticultural light have a wavelength selected from the range of 400-500 nm. Summary of the invention

[0004] Plants use the process of photosynthesis to convert light, CO2 and H2O into carbohydrates (sugars). These sugars are used to fuel metabolic processes. Excess sugars are used for biomass formation. This biomass formation includes stem elongation, increase in leaf area, flowering, fruit formation, etc. The photoreceptors responsible for photosynthesis are chlorophyll. In addition to photosynthesis, photoperiodism, phototropism and photomorphogenesis are also representative processes related to the interaction between radiation and plants:

[0005] Photoperiodism refers to the ability a plant has to sense and measure periods of radiation (e.g. to induce flowering),

[0006] Phototropism is the growth movement of plants towards and away from radiation, and

[0007] Photomorphogenesis refers to qualitative and quantitative changes in morphology in response to radiation.

[0008] The two important absorption peaks of chlorophyll a and b are located in the red and blue regions, especially from 625-675nm and from 425-475nm. In addition, there are other local peaks in the near UV region (300-400nm) and the far red region (700-800nm). The main photosynthetic activity seems to occur in the wavelength range of 400-700nm. The radiation in this range is called photosynthetically active radiation (PAR).

[0009] In the context of horticultural lighting, near UV is defined as one or more wavelengths selected from the 300-400nm spectral range, blue is defined as one or more wavelengths selected from the 400-500nm spectral range, white is defined as wavelengths selected from the 400-700nm spectral range (these selected wavelengths together can constitute white light, such as a wavelength combination of blue, green and red), green is defined as one or more wavelengths selected from the 500-600nm spectral range, red is defined as one or more wavelengths selected from the 600-700nm spectral range, deep red is defined as one or more wavelengths selected from the 640-700nm spectral range, and far red is defined as one or more wavelengths selected from the 700-800nm ​​spectral range. Thus, deep red is a subselection of red.

[0010] Other photosensitive processes in plants involve phytochromes. The activity of phytochromes directs different responses, such as leaf expansion, neighbor perception, shade avoidance, stem elongation, seed germination, and flowering induction. The phytochrome photosystem includes two forms of phytochromes, Pr and Pfr, which have their sensitivity peaks in the red at 660 nm and the far red at 730 nm, respectively.

[0011] In horticulture, photosynthetic photon flux density (PPFD) is measured in photons per unit area per second (in μmol / sec / m 2 As a unit; one mole corresponds to 6*10 23 In practice, when applying, for example, top lighting or a combination of top and mid lighting, especially for tomatoes, the red PPFD used may typically be 200 μmol / sec / m 2, and the ratio of blue:red may typically be 1:7 (wherein red and blue are particularly selected from 625-675 nm and particularly from 400-475 nm, respectively). In particular, the photosynthetic photon flux density may include approximately 10% blue and approximately 90% red. The PPFD may be determined by a photodiode (such as in combination with a filter), or such as by a spectrometer, or measured directly with a photomultiplier (optionally also in combination with a filter). The area in the PPFD refers to the local light receiving (plant) area of ​​the space in which the (one or more) light sources are arranged. In the case of a multi-layer system, it may be defined as the area of ​​the relevant layers included in the multi-layer configuration; the PPFD may then be estimated with respect to each layer individually (see also further below). The area may in one embodiment be a value manually fed to the control unit, or in one embodiment may be evaluated by the control unit (e.g. with a sensor).

[0012] The growth of plants may depend not only on the amount of light, but also on the spectral composition, duration and timing of the light on the plants. The combination of parameter values ​​according to these aspects is called a "light recipe" for growing plants (herein, the words plant and crop can be interchangeable).

[0013] LEDs can play a variety of roles in horticultural lighting, such as:

[0014] 1. Supplemental lighting: Lighting that supplements natural daylight is used to increase yields (of tomatoes, for example) or to extend crop production during periods when crop prices may be higher, such as fall, winter, and spring.

[0015] 2. Photoperiodic lighting: The daily duration of light is important for many plants. The ratio of light periods to dark periods in a 24-hour cycle affects the flowering response of many plants. Controlling this ratio with the aid of supplemental lighting enables the timing of flowering to be regulated.

[0016] 3. Sunlight-free cultivation in plant farms.

[0017] 4. Organizational cultivation.

[0018] In order to provide supplemental lighting in a greenhouse during the fall, winter and spring (or throughout the year in multi-layered growth), high-power gas discharge lamps are generally used, which must be mounted at a relatively high position above the plants to ensure sufficiently uniform light distribution on the plants. Currently, in greenhouses, different types of high-power lamps (e.g., high-power HIDs) ranging from 600W to 1000W are used to provide supplemental light for plants. One disadvantage is that the amount of light reaching the lower part of the plant from a position above the plant may be quite limited, depending on the type of crop. At the same time, the lower part of the plant is usually most in need of supplemental light. The same dilemma persists when solid-state lighting mounted above the plants is used. However, LED lighting (especially solid-state lighting) has some advantages over discharge-based lighting.

[0019] In situations where the light that plants receive from natural sunlight is insufficient, such as in northern regions or in so-called "plant farming" or "vertical farming" that relies entirely on artificial and well-controlled conditions, there seems to be a need to provide light for plant growth (leaves and fruits), ripening and pre-harvest conditioning.

[0020] Light is not the only enabling factor for growth, as the atmosphere (humidity levels, CO2 / O2 levels, etc.), water, nutrients and spore elements are also of great significance. Temperature (and the temperature profile / cycle during the day / night) is also a key factor in the success of plant growth. In the field of horticulture in controlled environments (such as greenhouses and plant farms), there seems to be a need for soilless cultivation or hydroponic gardening, which is now commonly used in high-profit / high-value cultivation. This method is also based on the unnatural growth of plants and may require or benefit from artificial optimization.

[0021] The space available for food production is becoming less and less. Innovations in production methods are needed to deliver higher yields from a smaller footprint while becoming more sustainable (minimum use of energy and water). Producing food in a closed environment such as a plant farm is one way to meet these needs. In a plant farm (also known as a plant factory, vertical farm or urban farm), food is grown in multiple layers, making better use of available space compared to outdoor growth or growth in a greenhouse. This means that daylight will not be able to reach all plants, and almost all light must come from artificial lighting. In a plant farm, it is necessary to provide the plants with the best light treatment at all times. At the same time, the light emitted by the LED modules must be used as efficiently as possible in order to reduce energy consumption and bring a profitable business. In a plant farm, the yield per unit area is much higher than that in the open field. The use of water is minimized. Plant diseases and pests can be more easily prevented.

[0022] In horticulture, relatively much light and therefore energy is used. Increasing yields while using fewer photons is key to the future of horticulture.

[0023] The term "horticulture" relates to the (intensive) cultivation of plants for human use, and its activities are very diverse, including edible plants (fruits, vegetables, mushrooms, culinary herbs) and non-edible crops (flowers, trees and shrubs, lawn grasses, hops, grapes, medicinal herbs). Horticulture is a branch of agriculture that involves the art, science, technology and business of growing plants. It can include the cultivation of medicinal plants, fruits, vegetables, nuts, seeds, herbs, sprouts, mushrooms, algae, flowers, seaweed and non-food crops (such as grasses and ornamental trees and plants). Here, the term "plant" is used to refer essentially to any species selected from medicinal plants, vegetables, herbs, sprouts, mushrooms, nut-bearing plants, seed-bearing plants, flowering plants, fruit-bearing plants, non-edible crops (such as grasses and ornamental trees), etc. In this article, the term "plant" is used for essentially all stages. The term "plant part" may refer to roots, stems, leaves, fruits (if any), etc. Even more particularly, the term "plant" is used to refer essentially to any species selected from medicinal plants, vegetables, herbs, sprouts, nut-bearing plants, seed-bearing plants, flowering plants, fruit-bearing plants, non-edible crops.

[0024] The term "crop" is used herein to refer to horticultural plants that are growing or have grown. Similar plants grown on a large scale for food, clothing, etc. can be called crops. Crops are non-animal species or varieties grown to be harvested as, for example, food, livestock feed, fuel, or for any other economic purpose. The term "crop" can also refer to a variety of crops. Horticultural crops can particularly refer to food crops (tomatoes, peppers, cucumbers and lettuce), as well as plants that (potentially) produce such crops, such as tomato plants, pepper plants, cucumber plants, etc. Horticulture can generally refer to, for example, crops and non-crop plants in this article.

[0025] In particular, the present invention relates to pepper plants, especially sweet pepper plants, which may include their stalks, flowers, fruits, leaves and stems.

[0026] Bell pepper is an important greenhouse crop. The crop can benefit from supplementary lighting for year-round production. A major problem in growing bell peppers seems to be the flushing pattern of the number of new fruit sets each week, which makes it very difficult to obtain a constant yield. It leads to large periodic fluctuations in weekly yield (i.e. the number of harvestable fruits), with a period of usually 4-5 weeks. The origin of this flushing pattern is as follows: (a) New flowers are usually produced at a constant rate (mainly determined by the greenhouse temperature); (b) Flowers quickly turn into small fruits (called fruit set); this takes about a week; (c) Plant load gradually increases (plant load is the number of fruits hanging on the plant); (d) Assimilates produced by photosynthesis are allocated to the fruits, causing them to grow. After 6-7 weeks, they are ready for harvest; (e) High plant load leads to less assimilates available for flowers and new fruit sets, with the result that a significant portion of flowers and new fruit sets will abort; (f) Plant load gradually decreases; (g) Due to the reduction in plant load, more assimilates become available for flowers and new fruit sets, resulting in fewer abortions; (h) Plant load will gradually increase again; (i) and so on. Therefore, a major problem in growing bell peppers is the flushing pattern in the number of new fruit set each week. Periods of good fruit set alternate with periods of poor fruit set (caused by flower abortion and new fruit set). This flushing pattern can result in a similar pattern in yield, albeit offset in time. Fluctuations in yield can be quite large. By strategically pruning flowers and new fruit set, growers attempt to reduce the magnitude of yield fluctuations. However, this is cumbersome in practice.

[0027] Therefore, one aspect of the present invention is to provide an alternative system, which preferably further at least partially obviates one or more of the above disadvantages.An object of the present invention may be to overcome or ameliorate at least one disadvantage of the prior art, or to provide a useful alternative.

[0028] According to a first aspect, the present invention provides a system for cultivating pepper plants (especially sweet pepper plants). The system may include a light generating device and a control system. In an embodiment, the light generating device may be configured to provide (supplementary) device light to the pepper plants. In particular, the (supplementary) device light may include one or more of red light and far-red light. Red light (R) may include one or more wavelengths within the range of 600-700nm. Far-red light (FR) may include one or more wavelengths within the range of 700-800nm. In particular, the system in the embodiment has an operable mode including a sensing phase, a planning phase, and an execution phase.

[0029] In an embodiment, the system may comprise a sensor system. In a further embodiment, the sensor system may be configured to determine (in a sensing phase) plant load related parameters of the pepper plants and provide input signals to the control system. In particular, the plant load related parameters may be selected from the group comprising plant load, flowering rate, flower abortion rate, (net) fruit set rate and fruit abortion rate. Furthermore, in an embodiment, the control system may be configured to determine (in a planning phase) a target R:FR ratio (range) of red light to far-red light (in μmol / m 2 / day), in particular based on the input signal and the plant load threshold. However, in an embodiment, the control system can be configured to (in the execution phase) expose the pepper plants to a target R:FR ratio by controlling the light generating device. In particular, in an embodiment, the plant load threshold, in particular the lower plant load threshold, or in particular the higher plant load threshold, can be determined by a target yield based on kilograms of fruit (and / or the number of fruits) and / or the timing of the pepper plants. Therefore, (one or more) plant load thresholds can be selected based on the target yield, wherein the target yield includes one or more of the (expected) number of fruits, the (expected) fruit quality and the (expected) fruit maturity time. In an embodiment, the target yield may include the (expected) number of fruits and the (expected) fruit quality, or related values, such as the (expected) fruit quality per fruit.

[0030] Typically, in embodiments, the upper plant load threshold may be higher than the lower plant load threshold, however, in embodiments, the upper plant load threshold and the lower plant load threshold may also be the same.

[0031] In an embodiment, the target yield may be associated with a (single) pepper plant. In a further embodiment, the target yield may be associated with a plurality of pepper plants. In a further embodiment, the target yield may relate to a group of plants, such as a group of plants in the (same) greenhouse section (see below).

[0032] Therefore, in particular, the present invention provides a system for cultivating pepper plants in an embodiment, wherein the system includes a light generating device and a control system, wherein the light generating device is configured to provide device light to the pepper plants, wherein the device light includes one or more of red light and far-red light, wherein the red light includes one or more wavelengths in the range of 600-700nm, and wherein the far-red light includes one or more wavelengths in the range of 700-800nm, wherein the system has an operational mode, wherein: the control system (300) is configured to obtain an input signal, wherein the input signal is related to a plant load-related parameter of the pepper plant, wherein the plant load-related parameter is selected from the group consisting of plant load, flowering rate, flower abortion rate, fruit set rate and A group of fruit abortion rates; the control system is configured to determine the plant load based on the input signal, and wherein one or more of the following apply: (i) the control system is configured to compare the plant load with a lower plant load threshold, and if the plant load is below the lower plant load threshold, select a target R:FR ratio of red light to far-red light that is above a threshold ratio T; and (ii) the control system is configured to compare the plant load with an upper plant load threshold, and if the plant load is above the upper plant load threshold, select a target R:FR ratio that is above the threshold ratio T, in particular wherein the threshold ratio T is selected from the range of 10-25; the control system is configured to expose the pepper plants to the target R:FR ratio by controlling the light generating device.

[0033] With such a system, the plant load can be more constant over time, and therefore, the yield can be more constant over time. For example, the number and / or total weight of the fruit can be more constant over time. Furthermore, with such a system, the quality of the fruit can also be more constant over time. Furthermore, with such a system, the cultivation of the plants can be easier, since the cultivation parameters can also be more constant. Thus, supplementary lighting can promote a more constant plant load and a more constant fruit quality, and thereby the cultivation of peppers can be further simplified.

[0034] As described above, the present invention provides a system for cultivating pepper plants. In particular, the pepper plants can be selected from the genus Capsicum. More particularly, the pepper plants can be selected from the group of annual peppers, berry peppers, Chinese peppers, bush peppers and hairy peppers. In particular, the pepper plants can be Capsicum annuum species. Note that the pepper plants are not part of the system, but the system can help cultivate pepper plants.

[0035] The term "plant" may also refer to a seed or a seedling. Thus, the term "plant" may generally refer to any stage from a seed to a (mature) plant. The term "plant" may also refer to a plurality of (different) plants.

[0036] In particular, the system may comprise a light generating device and a control system. In an embodiment, the system may further comprise a sensor system. In a further embodiment, the system, in particular the control system, may further comprise a user interface.

[0037] The light generating device can be configured to provide (supplement) device light to the pepper plant. Therefore, the system can be applied to the situation that the pepper plant only receives artificial light. In such an embodiment, red light and / or far-red light can be provided only by the light generating device of the system. In an alternative embodiment, the system is an additional system of an existing system, and can be configured to provide supplementary light to the artificial light of the existing system. The system can also be applied to the situation that the pepper plant receives artificial light during at least a portion of a day and at least a portion of a year. During a relatively dark period, such as night, dusk, dawn, cloudy days, a part of less light that may be received in any case in a year (such as winter), the system can provide supplementary light. This light can supplement the daylight it receives when the pepper plant receives daylight and / or when there is basically no daylight (such as, for example, during night, or during dusk, dawn, cloudy days, etc.).

[0038] The light generating device may be particularly configured to generate device light. In particular, the light generating device may include a light source. The light source may be particularly configured to generate light source light. In an embodiment, the device light may consist essentially of the device light. In other embodiments, the device light may consist essentially of converted light source light. In yet other embodiments, the device light may include (unconverted) light source light and converted light source light. The light source light may be converted into luminescent material light with a luminescent material and / or into up-converted light with an up-converter. The term "light generating device" may also refer to a plurality of light generating devices that can provide device light with substantially the same spectral power distribution. In a specific embodiment, the term "light generating device" may also refer to a plurality of light generating devices that can provide device light with different spectral power distributions.

[0039] The term "light source" may in principle relate to any light source known in the art. It may be a conventional (tungsten) bulb, a low-pressure mercury lamp, a high-pressure mercury lamp, a fluorescent lamp, an LED (light emitting diode). In a specific embodiment, the light source comprises a solid-state LED light source (such as an LED or a laser diode (or "diode laser")). The term "light source" may also relate to a plurality of light sources, for example 2-2000 (solid-state) LED light sources. Therefore, the term LED may also refer to a plurality of LEDs. In addition, the term "light source" may also refer to a so-called chip-on-board (COB) light source in an embodiment. The term "COB" refers in particular to an LED chip in the form of a semiconductor chip, which is neither packaged nor connected, but is directly mounted on a substrate such as a PCB. Therefore, a plurality of light-emitting semiconductor light sources may be configured on the same substrate. In an embodiment, a COB is a plurality of LED chips configured together into a single lighting module.

[0040] The light source may have a light escape surface. With reference to a conventional light source, such as a light bulb or a fluorescent lamp, this may be the outer surface of a glass or quartz housing. For an LED, this may be, for example, the LED die, or the outer surface of a resin when the resin is applied to the LED die. In principle, it may also be the end of an optical fiber. The term escape surface particularly relates to a part of the light source, where light actually leaves or escapes from the light source. The light source is configured to provide a light beam. The light beam (therefore) escapes from the light exit surface of the light source.

[0041] Likewise, the light generating device may comprise a light escape surface, such as an end window. Furthermore, likewise, the light generating system may comprise a light escape surface, such as an end window.

[0042] The term "light source" may refer to a semiconductor light emitting device, such as a light emitting diode (LED), a resonant cavity light emitting diode (RCLED), a vertical cavity laser diode (VCSEL), an edge emitting laser, etc. The term "light source" may also refer to an organic light emitting diode (OLED), such as a passive matrix light emitting diode (PMOLED) or an active matrix light emitting diode (AMOLED). In a specific embodiment, the light source comprises a solid-state light source (such as an LED or a laser diode). In an embodiment, the light source comprises an LED (light emitting diode). The term "light source" or "solid-state light source" may also refer to a superluminescent diode (SLED). The term LED may also refer to a plurality of LEDs. The term "light source" may also refer to a plurality of (substantially identical (or different)) light sources, such as 2-2000 solid-state light sources. In an embodiment, the light source may include one or more micro-optical elements (micro-lens arrays) downstream of a single solid-state light source (such as an LED) or downstream of a plurality of solid-state light sources (i.e., for example, shared by a plurality of LEDs). In an embodiment, the light source may include an LED with on-chip optics. In an embodiment, the light source comprises a pixelated single LED (with or without optics) (providing on-chip beam control in an embodiment).

[0043] In an embodiment, the light source may be configured to provide primary radiation, which is used in this way, such as, for example: a blue light source, such as a blue LED; or a green light source, such as a green LED; and a red light source, such as a red LED. Such an LED, which may not include a luminescent material ("phosphor"), may be represented as a direct color LED. However, in other embodiments, the light source may be configured to provide primary radiation, and a portion of the primary radiation is converted into secondary radiation. The secondary radiation may be based on the conversion of the luminescent material. The secondary radiation may therefore also be indicated as luminescent material radiation. In an embodiment, the luminescent material may be included by the light source, such as an LED having a luminescent material layer or a dome including luminescent material. Such an LED may be represented as a phosphor conversion LED or a PC LED (phosphor conversion LED). In other embodiments, the luminescent material may be configured at a distance ("far away") from the light source, such as an LED having a luminescent material layer that is not in physical contact with the die of the LED. Therefore, in a specific embodiment, the light source may be a light source that emits at least light of a wavelength selected from the range of 380-470nm during operation. However, other wavelengths may also be possible. This light may be partially used by the luminescent material for conversion into other light. In an embodiment, the light generating device may include a luminescent material. In an embodiment, the light generating device may include a PC LED. In other embodiments, the light generating device may include a direct LED (i.e., without phosphor). In an embodiment, the light generating device may include a laser device, such as a laser diode. In an embodiment, the light generating device may include a super luminescent diode. Thus, in a specific embodiment, the light source may be selected from the group of a laser diode and a super luminescent diode. In other embodiments, the light source may include an LED.

[0044] The light source may in particular be configured to generate a source light having an optical axis (O) (beam shape) and a spectral power distribution. In an embodiment, the source light may comprise one or more bands having a known bandwidth of the laser.

[0045] The term "light source" may (thus) refer to such a light generating element, such as, for example, a solid-state light source, or, for example, to a packaging of a light generating element (such as a solid-state light source), and one or more luminescent material containing elements and (other) optical devices, such as lenses, collimators. A light converter element ("converter element" or "converter") may include a luminescent material containing element. For example, a solid-state light source like a blue LED is a light source. A combination of a solid-state light source (as a light generating element) and a light converter element (such as a blue LED and a light converter element) optically coupled to the solid-state light source may also be a light source (but may also be denoted as a light generating device). Thus, a white LED is a light source (but may, for example, also be denoted as a (white) light generating device).

[0046] The term "light source" herein may also refer to light sources including solid state light sources, such as LEDs or laser diodes or super luminescent diodes.

[0047] In embodiments, the term "light source" may (therefore) also refer to light sources that are (also) based on light conversion, e.g. in combination with luminescence conversion materials. Thus, the term "light source" may also refer to a combination of an LED and a luminescent material configured to convert at least part of the LED radiation, or to a combination of a (diode) laser and a luminescent material configured to convert at least part of the (diode) laser radiation. In embodiments, the term "light source" may also refer to a combination of a light source (e.g. an LED) and an optical filter, which may change the spectral power distribution of the light generated by the light source. In particular, the term "light generating device" may be used to refer to a light source as well as further (optical components), like filters and / or beam shaping elements etc.

[0048] In an embodiment, the phrase "different light sources" or "a plurality of different light sources" and similar phrases may refer to a plurality of solid-state light sources selected from at least two different bins. Likewise, the phrase "same light source" or "a plurality of same light sources" and similar phrases may refer to a plurality of solid-state light sources selected from the same bin in an embodiment.

[0049] The terms "solid-state light source" or "solid-state material light source" and similar terms may particularly refer to semiconductor light sources, such as light emitting diodes (LEDs), diode lasers or superluminescent diodes.

[0050] In particular, the spectral power distribution of the device light may be controllable. Therefore, a control system (see also below) may be applied to control the spectral power distribution. In a specific embodiment, the system comprises at least two types of light generating devices. The light generating device of the first type may be configured to provide device light comprising more red light than far-red light, for example substantially no far-red light. The light generating device of the second type may be configured to provide device light comprising more far-red light than red light, for example substantially no red light. In particular, the control system may be configured to separately control the light generating device of the first type and the light generating device of the second type. The term "type of light generating device" and similar terms may refer to one or more light generating devices of this type. In a specific embodiment, the (one or more) light generating devices comprise a solid-state light source, in particular an LED.

[0051] Thus, the (supplementary) device light may include one or more of red light and far-red light. In particular, the red light may include one or more wavelengths in the range of 600-700nm. Furthermore, in particular the far-red light may include one or more wavelengths in the range of 700-800nm. The red light may have a spectral power distribution in the wavelength range of 600-800nm, wherein at least 70% of the spectral power is in the range of 600-700nm, more particularly at least 80%, such as at least 90%. Alternatively or additionally, the far-red light may include one or more wavelengths in the range of 700-800nm. The far-red light may have a spectral power distribution in the wavelength range of 600-800nm, wherein at least 70% of the spectral power is in the range of 700-800nm, more particularly at least 80%, such as at least 90%.

[0052] The phrase "the red light may include one or more wavelengths in the range of 600-700 nm" and similar phrases indicate that the red light may be comprised of one or more of (i) one or more narrow emission bands and (ii) one or more broad emission bands. Thus, at one extreme, the red light may be provided by a laser that provides substantially monochromatic light in the red wavelength range, and at another extreme, due to the use of one or more broad emission bands and / or multiple narrow emission bands, intensity may be present at substantially all wavelengths. Similarly, the phrase "the far-red light may include one or more wavelengths in the range of 700-800 nm" and similar phrases indicate that the far-red light may be comprised of one or more of (i) one or more narrow emission bands and (ii) one or more broad emission bands. Thus, at one extreme, the far-red light may be provided by a laser that provides substantially monochromatic light in the far-red wavelength range, and at another extreme, due to the use of one or more broad emission bands and / or multiple narrow emission bands, intensity may be present at substantially all wavelengths.

[0053] The system has an operational mode which can particularly include (a) obtaining (or determining) parameters related to the plant load of a pepper plant and providing an input signal to the control system, (b) determining a target R:FR ratio (range) of red light to far-red light based on the input signal and a plant load threshold, and (c) exposing the pepper plant to the target R:FR ratio by controlling a light generating device. Thus, the system can have an operational mode which can particularly include a sensing phase (or "acquisition phase"), a planning phase, and an execution phase, wherein: (a) (in the sensing phase) the control system can (be configured to) obtain an input signal, where the input signal relates to (or includes) parameters related to the plant load of the pepper plant, in particular where a sensor system can be configured to determine parameters related to the plant load of the pepper plant and provide an input signal to the control system, or in particular where a user interface is configured to receive user input and provide an input signal to the control system, (b) (in the planning phase) the control system can be configured to determine a target R:FR ratio (range) of red light to far-red light (in units of μmol / m 2 / day) based on the input signal and a plant load threshold, and (c) (in the execution phase) the control system can be configured to expose the pepper plant to the target R:FR ratio by controlling a light generating device.

[0054] In particular, in a further embodiment, if the plant load is below a lower plant load threshold, the target R:FR ratio (range) can particularly be selected to be higher than a threshold ratio T, and if the plant load is above a higher plant load threshold, the target R:FR ratio (range) can particularly be selected to be lower than the threshold ratio T. In an embodiment, the threshold ratio T can be selected from the range of 1 - 50, such as the range of 5 - 40, in particular the range of 10 - 25, such as the range of 12 - 18, in particular the range of 13 - 17. In a further embodiment, if the plant load is below a lower plant load threshold, the target R:FR ratio (range) can particularly be selected to be > 1*T, especially ≥ 1.05*T, such as ≥ 1.1*T, especially ≥ 1.2*T. In a further embodiment, if the plant load is above a higher plant load threshold, the target R:FR ratio (range) can particularly be selected to be < T, especially ≤ 0.95*T, such as ≤ 0.9*T, especially ≤ 0.8*T.

[0055] In principle, any target R:FR ratio may be selected as device light without red light or far-red light. Thus, in an embodiment, the target R:FR ratio may be selected from a range of 0-∞, such as a range of 0.1-100, in particular a range of 0.5-60, such as a range of 5-30. Thus, in an embodiment, the target R:FR ratio may be selected as (substantially) 0 or (substantially) ∞, i.e., in an embodiment, device light may be provided that is (substantially) free of red light (and substantially only comprises far-red light) or far-red light (and substantially only comprises red light), respectively.

[0056] Thus, during cultivation of the plants over time, the R:FR ratio may also vary over time and may show substantially periodic fluctuations (such as a period of approximately 4-5 weeks).

[0057] In other embodiments, the threshold ratio T may be (approximately) 14, or (approximately) 15, or (approximately) 16.

[0058] In particular, the plant load related parameter can be selected from the group including plant load, flowering rate, flower abortion rate, (net) fruit setting rate and fruit abortion rate. In particular, the plant load can be defined as the number of fruits on the plant. In addition, in particular the flowering rate can be defined as the number of new flowers per plant and per week. In addition, in particular the flower abortion rate can be defined as the number of flowers that will abort per plant and per week. In addition, in particular the fruit setting rate can be defined as the number of new fruits per plant and per week. In addition, in particular the fruit abortion rate can be defined as the number of fruits that will abort per plant and per week. In addition, in particular the net fruit setting rate can be defined as the number of new fruits per plant and per week, which remain on the plant until harvest. In addition, the yield can be defined as the number of fruits that can be harvested per plant per week. In an embodiment, two or more plant load related parameters can be selected. This can increase the reliability of the system and / or method.

[0059] In an embodiment, the control system may be configured to determine a time derivative of the plant load based on the input signal. In such an embodiment, one or more of the following may be applied in particular: (i) the control system may (be configured to) compare the time derivative of the plant load with a plant load time derivative threshold, and (be configured to) if the time derivative of the plant load is above the plant load time derivative threshold, select a target R:FR ratio < threshold ratio T; and (ii) the control system may (be configured to) compare the time derivative of the plant load with a plant load time derivative threshold, and (be configured to) if the time derivative of the plant load is below the plant load time derivative threshold, select a target R:FR ratio > threshold ratio T. In particular, in an embodiment, the threshold ratio T may be selected from a range of 10-25, such as from a range of 13-17. In particular, by determining the R:FR ratio or the target phytochrome stable state (see below) based on the derivative, the control system may more conveniently act in a counter-cyclical manner.

[0060] In one aspect, the present invention also provides a system for cultivating pepper plants, wherein the system includes a light generating device and a control system, wherein the light generating device is configured to provide device light to the pepper plants, wherein the device light includes one or more of red light and far-red light, wherein the red light includes one or more wavelengths in the range of 600-700nm, and wherein the far-red light includes one or more wavelengths in the range of 700-800nm; wherein the system has an operational mode, wherein: (a) the control system is configured to obtain (or determine) an input signal, wherein the input signal is related to a plant load-related parameter of the pepper plant, wherein the plant load-related parameter is selected from the group including plant load, flowering rate, flower abortion rate, fruit set rate and fruit abortion rate; (b) the control system is Configured to determine a target phytochrome stable state based on an input signal and a plant load threshold, in particular wherein one or more of the following apply: (i) the control system is configured to compare the plant load with a lower plant load threshold, and if the plant load is below the lower plant load threshold, select the target phytochrome stable state from a range of >0.87 (such as ≥0.88); and (ii) the control system is configured to compare the plant load with an upper plant load threshold, and if the plant load is above the upper plant load threshold, select the target phytochrome stable state from a range of <0.87 (such as ≤0.86); and (c) (in the execution phase) the control system can be configured to place the pepper plant in the target phytochrome stable state by controlling the light generating device.However, in one aspect, the present invention also provides a system for cultivating pepper plants, wherein the system comprises a light generating device, a sensor system and a control system, wherein the light generating device is configured to provide (supplementary) device light to the pepper plants, wherein the (supplementary) device light comprises one or more of red light and far-red light, wherein the red light comprises one or more wavelengths in the range of 600-700nm, and wherein the far-red light comprises one or more wavelengths in the range of 700-800nm, wherein the system has an operational mode, wherein: (a) (in the sensing phase) the sensor system is configured to acquire (or determine) plant load related parameters of the pepper plants and provide input signals to the control system, wherein the plant load related parameters are selected from the group consisting of plant load, flowering rate, flower abortion rate, (net) fruit set rate and fruit abortion rate. ; (b) (in the planning stage) the control system can be configured to determine a target phytochrome stability state based on the input signal and the plant load threshold, in particular wherein one or more of the following apply: (i) the control system is configured to compare the plant load with a lower plant load threshold, and if the plant load is below the lower plant load threshold, select the target phytochrome stability state from a range of >0.87 (such as ≥0.88); and (ii) the control system is configured to compare the plant load with an upper plant load threshold, and if the plant load is above the upper plant load threshold, select the target phytochrome stability state from a range of <0.87 (such as ≤0.86); and (c) (in the execution stage) the control system can be configured to place the pepper plant in the target phytochrome stability state by controlling the light generating device.

[0061] The formula for the stable state of phytochrome is as follows:

[0062]

[0063] Here, N(λ) is the photon flux density (in mol / m 2 / s), which depends on the wavelength (λ). In addition, σ r and σ fr They are P r and P fr Phytochrome photochemical cross sections are measured in square meters per mole. These are also wavelength dependent. Sager et al. gave σ r and σ frDependence on wavelength: JC Sager, WO Smith, JL Edwards, KL Cyr (1988), Photosynthetic efficiency and phytochrome photoequilibria determination using spectral data, Transactions of the ASAE, 31(6), 1882-1889.

[0064] In an embodiment, (in the planning phase) the control system may be configured to determine the plant load based on the input signal. Furthermore, one or more of the following may apply: (i) the control system may be configured to compare the plant load with a lower plant load threshold, and if the plant load is below the lower plant load threshold, select a target R:FR ratio > threshold ratio T, and (ii) the control system may be configured to compare the plant load with an upper plant load threshold, and if the plant load is above the upper plant load threshold, select a target R:FR ratio < threshold ratio T, in particular wherein T is selected from the range of 10-25, such as from the range of 10-20. In particular, in an embodiment, one or more of the following apply: (a) the control system may be configured to select a target R:FR ratio > 20 if the plant load is below the lower plant load threshold, and (b) the control system may be configured to select a target R:FR ratio < 10 if the plant load is above the upper plant load threshold.

[0065] In embodiments, the plant load may be a predicted plant load, and in other embodiments, the plant load may be a current plant load.Thus, the control may for example be based on a feedback principle and / or a feedforward principle.

[0066] In an embodiment, the system may include a sensor system. The sensor system may be configured to determine plant load related parameters of the pepper plants and to provide input signals, in particular relevant sensor input signals, to the control system.

[0067] The sensor system may include fixed sensors, for example arranged in a horticultural system like a greenhouse or a plant factory (or climate unit), such as above the plants or between the plants. Alternatively or additionally, the sensor system may include a movable sensor device configured to determine a plant load-related parameter. The movable sensor device may include a drone, a driving robot, a sensor movable along a track, a sensor with one or two degrees of freedom of movement (such as a rotatable sensor), etc.

[0068] In particular, the sensor system may include a camera. The sensor system may be based on a camera in combination with computer vision software, for example to detect and count one or more of flowers, fruits and optionally other plant parameters such as one or more of the number of leaves, leaf size, leaf color, etc. In this way, for each plant or selection of plants, for example the number of fruits on the plant (plant load) can be determined.

[0069] As described above, in an embodiment, the system may include a sensor system. In such an embodiment, in an operational mode, in particular in a sensing phase, the sensor system may (is configured to) determine a plant load related parameter of the pepper plant and provide a related sensor input signal to the control system. Thus, the input signal may include the related sensor input signal. In a further embodiment, the control system may (is configured to) determine the plant load based on the related sensor input signal.

[0070] In an embodiment, in particular, the plant load may be provided as a (user) input. In particular, in an embodiment, the system (in particular the control system) may comprise a user interface. In such an embodiment, in an operational mode, in particular in a sensing phase, the user interface may be configured to receive user input regarding plant load related parameters of the pepper plants and to provide relevant user input signals (to the control system). Thus, the input signal may comprise a user input signal. In a further embodiment, in an operational mode, in particular in a planning phase, the control system may (be configured to) determine the plant load based on the relevant user input signals.

[0071] In a specific embodiment, the grower may directly provide the plant load number. Such a number may be obtained by regularly counting the number of fruits on selected plants in the greenhouse and averaging the results. This information or information derived therefrom may be provided to the system via a user interface.

[0072] Alternatively, the grower numbers each new flower (the first flower on the plant is numbered 1, the second flower is numbered 2, etc., for example using a sticker or other label) or numbers each new fruit. Each week, the grower records the number of new peppers that last appeared on the plant, as well as the number of peppers that were last harvested. From this bookkeeping, the plant load can then be determined relatively easily. Usually, these numbers are entered manually in an app on a tablet, after which the data is sent to a data platform and converted into plant load data by an algorithm.

[0073] As described above, in embodiments, the device light may be provided every day. Furthermore, in embodiments, the device light may be provided only during part of the day. However, in embodiments, the device light may be provided only during certain periods of the year. In a specific embodiment, the control system may be configured to control the light generating device to subject the pepper plants to at least 5 mol / m 2 / day's (total) light exposure. Thus, when the light dose due to received daylight is below the indicated minimum value, the device may provide supplementary device light to obtain the desired (daily) exposure. However, when the light dose due to received daylight is equal to or above the indicated minimum value, the device may still provide supplementary device light according to the principles defined herein. However, in the latter case, the effect of the R:FR ratio in the (supplementary) device light may be less pronounced.

[0074] In yet a further aspect, the invention also provides a horticultural system comprising a system as defined herein. In particular, in an embodiment, the horticultural system may comprise a horticultural space for housing pepper plants, and the system may be configured to provide an equipment light to the horticultural space.

[0075] The gardening space may in particular be provided by a gardening arrangement. In particular, the term "gardening arrangement" refers to a plant factory or a climate unit, in which plants are grown under controlled conditions and in which the plants receive substantially no daylight. Furthermore, such a plant factory may be climatized, for example in the case of a climate unit. Thus, in an embodiment, a gardening arrangement comprises such a plant factory or a climate unit. In the present context, the term plant factory is regarded as covering embodiments of a climate unit.

[0076] However, the present invention is not limited to gardening arrangements in which the plants receive substantially only artificial light. Thus, the gardening space may also be provided by a greenhouse (or glass house) or other arrangement that allows daylight to enter. Thus, the gardening arrangement may also be an arrangement with walls and / or a roof made primarily of transparent material (e.g. glass) that is configured to cultivate plants, such as pepper plants. Thus, in a particular embodiment, the gardening space may be configured to receive natural daylight, and the device light may include supplemental device light.

[0077] Thus, in embodiments, a horticultural system may include one or more of a greenhouse and a vertical farm.

[0078] Also as described above, in an embodiment, the system can be configured to provide supplemental device light during low natural lighting periods, particularly during low natural lighting periods in the second half of the day, such as in the last 8 hours of the day, particularly in the afternoon (late afternoon) or evening. During low natural lighting periods, the photon flux density of natural daylight may be ≤500 μmol / m in the 400-700 nm region. 2 / s. In particular, as described above, the R:FR ratio of the device light can affect the state of plant phytochromes, which can naturally switch between different states as a factor of the light to which they are exposed. Therefore, by setting the phytochrome state with exposure to (supplemental) device light later in the day, the phytochrome state can remain stable for a (relatively) longer period of time because exposure to light that would reset (or reverse) the phytochrome state may be (relatively) low during the night.

[0079] In yet another aspect, the present invention also provides a method for cultivating pepper plants. In an embodiment, the method may include a sensing phase, a planning phase, and an execution phase. In an embodiment, the method may include (i) obtaining an input signal, wherein the input signal relates to a plant load-related parameter of the pepper plant, in particular by determining the plant load-related parameter of the pepper plant and providing the input signal, (ii) determining a target R:FR ratio (range) of red light to far-red light (in μmol / m 2 / day), in particular determining the plant load based on the input signal, and performing one or more of the following: (a) comparing the plant load with a lower plant load threshold, and if the plant load is below the lower plant load threshold, selecting a target R:FR ratio of red light to far-red light that is above a threshold ratio T; and (b) comparing the plant load with an upper plant load threshold, and if the plant load is above the upper plant load threshold, selecting a target R:FR ratio below the threshold ratio T, in particular wherein the threshold ratio T is selected from the range of 10-25, such as the range of 13-17, and (iii) exposing the pepper plants to the target R:FR ratio by providing the device light. In particular, the plant load related parameter may be selected from the group consisting of plant load, flowering rate, flower abortion rate, (net) fruit set rate and fruit abortion rate. Furthermore, the red light may include one or more wavelengths in the range of 600-700nm, and the far-red light may include one or more wavelengths in the range of 700-800nm. In particular, the present invention provides a method for cultivating pepper plants in an embodiment, comprising: (a sensing phase, which comprises) determining a plant load-related parameter of the pepper plant and providing an input signal, wherein the plant load-related parameter can be selected from a group including plant load, flowering rate, flower abortion rate, (net) fruit setting rate and fruit abortion rate; (a planning phase, which comprises) determining a target R:FR ratio (range) of red light to far-red light (in μmol / m 2 / day), wherein the red light may include one or more wavelengths in the range of 600-700nm, and wherein the far-red light may include one or more wavelengths in the range of 700-800nm; and (an execution phase, which includes) exposing the pepper plants to a target R:FR ratio by providing device light.

[0080] In particular, the present invention provides, in yet another aspect, a method for cultivating pepper plants, comprising: (a sensing phase, which includes) determining plant load-related parameters of the pepper plants and providing an input signal, wherein the plant load-related parameters can be selected from the group consisting of plant load, flowering rate, flower abortion rate, (net) fruit set rate, and fruit abortion rate; (a planning phase, which includes) determining a target photosensitive pigment stability state based on the input signal and a plant load threshold; and (an execution phase, which includes) placing the pepper plants in a target photosensitive pigment stability state by providing device light.

[0081] The embodiments described with respect to the system can also be applied to the method. However, some specific embodiments are also described in more detail with respect to the method.

[0082] As can be derived from the above, in embodiments, the method (particularly the planning phase) may include determining a plant load based on an input signal, and performing one or more of the following: (i) comparing the plant load to a lower plant load threshold, and if the plant load is below the lower plant load threshold, selecting a target R:FR ratio > threshold ratio T (from a range of > threshold ratio T), and (ii) comparing the plant load to an upper plant load threshold, and if the plant load is above the upper plant load threshold, selecting a target R:FR ratio < threshold ratio T (from a range of < threshold ratio T). In particular, in embodiments, the method may include one or more of the following: (a) if the plant load is below the lower plant load threshold, selecting a target R:FR ratio > 15, such as ≥ 20 (from a range of > 15), and (b) if the plant load is above the upper plant load threshold, selecting a target R:FR ratio < 15, such as ≤ 10 (from a range of < 15). In embodiments, the plant load may be a predicted plant load, or the plant load may be a current plant load. Furthermore, as mentioned above, in embodiments, the method may (further) comprise exposing the pepper plants to (at least partly) natural daylight. However, in embodiments, the method may comprise providing (supplementary) device light during periods of low natural lighting, in particular during periods of low natural lighting in the second half of the day, e.g. in the last 8 hours of the day, in particular in the (late) afternoon or evening. For example, during periods of low natural lighting, the photon flux density of natural daylight may be ≤ 500 μmol / m 2 / s. In particular, the target R:FR ratio may be a daily target R:FR ratio, in particular for (supplemental) device light, or in particular for total light (which comprises both natural light and device light). Furthermore, in an embodiment, the method may comprise using a system as defined herein or using a horticultural system as defined herein.

[0083] The term "control" and similar terms refer in particular at least to determining the operation of a behavior or a supervisory element. Therefore, in this article, "control" and similar terms may, for example, refer to applying behavior (determining the operation of a behavior or a supervisory element) to an element, such as, for example, measuring, displaying, actuating, opening, moving, changing temperature, etc. In addition, the term "control" and similar terms may additionally include monitoring. Therefore, the term "control" and similar terms may include applying behavior to an element, and applying behavior to an element and monitoring the element. The control of the element may be completed with a control system, which may also be indicated as a "controller". Therefore, the control system and the element may be functionally coupled at least temporarily or permanently. The element may include a control system. In an embodiment, the control system and the element may not be physically coupled. Control may be completed via wired and / or wireless control. The term "control system" may also refer to a plurality of different control systems, which are particularly functionally coupled, and wherein, for example, one control system may be a master control system, and one or more other control systems may be slave control systems. The control system may include or may be functionally coupled to a user interface.

[0084] The control system may also be configured to receive and execute instructions from a remote control. In an embodiment, the control system may be controlled via an App on a device, such as a portable device (e.g., a smartphone or I-phone, a tablet, etc.). Therefore, the device is not necessarily coupled to the lighting system, but may be (temporarily) functionally coupled to the lighting system. Therefore, in an embodiment, the control system may (also) be configured to be controlled by an App on a remote device. In such an embodiment, the control system of the lighting system may be a slave control system or a control in slave mode. For example, the lighting system may be identified by a code, in particular a unique code for the corresponding lighting system. The control system of the lighting system may be configured to be controlled by an external control system, which accesses the lighting system based on knowledge of the (unique) code (input via a user interface or input using an optical sensor (e.g., a QR code reader)). The lighting system may also include components for communicating with other systems or devices, such as based on Bluetooth, Thread, WIFI, LiFi, ZigBee, BLE or WiMAX, or other wireless technologies.

[0085] The system or device or equipment may perform actions in a "mode" or "operating mode" or "operable mode". The term "operable mode" may also be indicated as a "control mode". Similarly, in a method, an action or phase or step may be performed in a "mode" or "operating mode" or "operable mode". This does not exclude that the system, or device, or equipment may also be adapted to provide another control mode, or multiple other control modes. Similarly, this may not exclude that one or more other modes may be performed before and / or after the execution of the mode.

[0086] However, in an embodiment, a control system may be available, which is adapted to provide at least a control mode. If other modes are available, the selection of such a mode may in particular be performed via a user interface, although other options (such as executing a mode depending on a sensor signal or a (time) scheme) may also be possible. In an embodiment, an operating mode may also refer to a system, or a device, or an apparatus that can only operate in a single operating mode (i.e. "on", without further tunability).

[0087] Thus, in an embodiment, the control system may be controlled depending on one or more of an input signal of a user interface, a sensor signal (of a sensor), and a timer.The term "timer" may refer to a clock and / or a predetermined time scheme.

[0088] In yet another aspect, the present invention also provides a lamp or luminaire comprising a light generating system as defined herein. The luminaire may further include a housing, an optical element, a shutter, and the like. The lamp or luminaire may further include a housing enclosing the light generating system. The lamp or luminaire may include a light window or housing opening in the housing through which system light may escape from the housing. The light generating device may include a housing or carrier configured to accommodate or support one or more elements of the light generating system. For example, in an embodiment, the light generating device may include a housing or carrier configured to accommodate or support (one or more) light generating devices.

[0089] In this context, the term "visible light" especially relates to light having a wavelength selected from the range of 380-780 nm. BRIEF DESCRIPTION OF THE DRAWINGS

[0090] Embodiments of the invention will now be described, by way of example only, with reference to the accompanying schematic drawings, in which corresponding reference numerals indicate corresponding parts, and in which:

[0091] Figure 1 schematically depicts embodiments of systems and horticultural systems; and

[0092] Figure 2Some aspects of the invention are schematically depicted.The schematic drawings are not necessarily to scale. DETAILED DESCRIPTION

[0093] Figure 1 An embodiment of a system 1000 for cultivating a pepper plant 10 is schematically depicted. Note that the pepper plant 10 is not part of the system 1000. The system 1000 can be used to cultivate a pepper plant 10. The pepper plant 10 can be selected from the genus Capsicum, in particular the pepper plant 10 can be a Capsicum species. Reference numeral 15 refers to a bell pepper (fruit). The system 1000 can include a light generating device 100 and a control system 300. The light generating device 100 can be configured to provide (supplemental) device light 101 to the pepper plant 10. The light generating device 100 can in particular be a solid-state based light generating device, such as a light generating device 100 including one or more LEDs. The (supplemental) device light 101 can include one or more of red light and far-red light. The red light can include one or more wavelengths in the range of 600-700nm, and the far-red light can include one or more wavelengths in the range of 700-800nm. The system 1000 has an operational mode, which includes: (a) (in the sensing phase) acquiring an input signal, wherein the input signal relates to (or includes) a plant load related parameter of the pepper plant 10; (b) (in the planning phase) the control system 300 can be configured to determine a target R:FR ratio (range) of red light to far-red light (in μmol / m 2 / day), in particular wherein the control system 300 is configured to determine the plant load based on the input signal, and wherein one or more of the following apply: (i) the control system 300 is configured to compare the plant load with a lower plant load threshold, and if the plant load is below the lower plant load threshold, select the target R:FR ratio of red light to far-red light from a range > threshold ratio T, and (ii) the control system 300 is configured to compare the plant load with an upper plant load threshold, and if the plant load is above the upper plant load threshold, select the target R:FR ratio from a range < threshold ratio T, in particular wherein the threshold ratio T is selected from a range of 10-25, such as from a range of 13-17; and (c) (in the execution phase) the control system 300 may be configured to expose the pepper plants 10 to the target R:FR ratio by controlling the light generating device 100. The plant load related parameter may be selected from the group consisting of plant load, flowering rate, flower abortion rate, (net) fruit set rate and fruit abortion rate.

[0094] In particular, in an embodiment, the system 1000 may include a sensor system 200. In such an embodiment, in an operational mode, in particular in a sensing phase, the sensor system 200 may be configured to determine plant load related parameters of the pepper plant 10 and provide input signals to the control system 300. In particular, in such an embodiment, in the operational mode (a) (in the sensing phase) the sensor system 200 may be configured to determine plant load related parameters of the pepper plant 10 and provide relevant sensor input signals to the control system 300; and (b) (in the planning phase) the control system 300 may be configured to determine the plant load based on the relevant sensor input signals.

[0095] In another embodiment, the system 1000 (particularly the control system 301) may include a user interface. In such an embodiment, in an operational mode: (a) (in the sensing phase) the user interface 301 is configured to receive user input about plant load related parameters of the pepper plant 10 and provide the control system 300 with relevant user input signals; and (b) (in the planning phase) the control system 300 is configured to determine the plant load based on the relevant user input signals.

[0096] System 1000 may include one or more sensor systems 200 and a user interface 301 .

[0097] Alternatively, (in the planning phase) the control system 300 may be configured to determine a target phytochrome stability state based on the input signal and the plant load threshold, and (in the execution phase) the control system 300 may be configured to place the pepper plant 10 in the target phytochrome stability state by controlling the light generating device 100.

[0098] In an embodiment, (in the planning phase) the control system 300 may be configured to determine the plant load based on the input signal. In particular, one or more of the following apply: (i) the control system 300 may be configured to compare the plant load with a lower plant load threshold, and if the plant load is likely to be below the lower plant load threshold, select a target R:FR ratio>threshold ratio T; and (ii) the control system 300 may be configured to compare the plant load with an upper plant load threshold, and if the plant load is likely to be above the upper plant load threshold, select a target R:FR ratio<threshold ratio T. In particular, one or more of the following apply: (a) if the plant load is likely to be below the lower plant load threshold, the control system 300 may be configured to select a target R:FR ratio>15, such as ≥20; and (b) if the plant load is likely to be above the upper plant load threshold, the control system 300 may be configured to select a target R:FR ratio<15, such as ≤10. In addition, the plant load may be a predicted plant load, or the plant load may be a current plant load.

[0099] In an embodiment, the sensor system 200 may include a movable sensor device 210 configured to determine a plant load related parameter.

[0100] The control system 300 may be specifically configured to control the light generating device 100 to subject the pepper plants 10 to at least 6 mol / m 2 / d, such as at least 10 mol / m 2 / d, especially at least 14 mol / m 2 / d of (total) light exposure.

[0101] In an embodiment, the target R:FR ratio (range) may be a (total) daily target R:FR ratio (range) including natural daylight 1 and (supplementary) device light 101. In such an embodiment, if the plant load is below a lower plant load threshold, the target R:FR ratio (range) may in particular be selected to be >1.2, such as ≥1.3, especially ≥1.4, and if the plant load is above an upper plant load threshold, the target R:FR ratio (range) may in particular be selected to be <1.2, such as ≤1.1, especially ≤1.0.

[0102] Thus, in embodiments where a target R:FR ratio is obtained, the device light may have a spectral power distribution corresponding to the target R:FR ratio. In other embodiments, the target R:FR ratio may be a daily target R:FR ratio, and integrating the device light over a day may provide the target R:FR ratio.

[0103] In particular, in further embodiments, if the plant load is below a lower plant load threshold, the target R:FR ratio (range) can in particular be selected to be higher than the daily threshold ratio Td, and if the plant load is above a higher plant load threshold, it can in particular be selected to be lower than the daily threshold ratio Td. In an embodiment, the daily threshold ratio Td can be selected from the range of 0.8 - 2.0, such as the range of 1.0 - 1.8, in particular the range of 1.1 - 1.6, such as the range of 1.3 - 1.5. In further embodiments, if the plant load is below a lower plant load threshold, the target R:FR ratio (range) can in particular be selected to be > Td, in particular ≥ 1.05 * Td, such as ≥ 1.1 * Td, in particular ≥ 1.2 * Td. In further embodiments, if the plant load is above a higher plant load threshold, the target R:FR ratio (range) can in particular be selected to be < Td, especially ≤ 0.95 * Td, such as ≤ 0.9 * Td, especially ≤ 0.8 * Td.

[0104] In further embodiments, the device light 101 can include a spectrum according to (or “matching”) the target R:FR ratio. In further embodiments, the R:FR ratio (range) can be the daily target R:FR ratio (range) of the (supplemental) device light 101, i.e., the device light can be provided such that the integral of the (supplemental) device light 101 over a day is according to the R:FR ratio.

[0105] Figure 1 An embodiment of a horticultural system 400 including the system 1000 is also schematically depicted. The horticultural system 400 can include a horticultural space 410 for accommodating pepper plants 10. The system 1000 can be configured to provide the device light 101 to the horticultural space 410. The horticultural space 410 can be configured to receive natural daylight 1, and the device light 101 can include supplemental device light. The horticultural system can include one or more of a greenhouse and a vertical farm.

[0106] In a specific embodiment, the system 1000 can be configured to provide supplemental device light during low natural lighting periods. For example, during low natural lighting periods, the photon flux density of the natural daylight 1 in the 400 - 700 nm region may be ≤ 500 μmol / m 2 / s.

[0107] As described above, the present invention also provides a method for cultivating pepper plants 10, which may include: (a) (sensing phase, which includes) obtaining an input signal, wherein the input signal relates to (or includes) a plant load-related parameter of the pepper plant 10. In an embodiment, the method (especially the sensing phase) may include determining a plant load-related parameter of the pepper plant 10 and providing a (related) input signal, (b) (planning phase, which includes) determining a target R:FR ratio (range) of red light to far-red light (in μmol / m 2 / day as a unit), and (c) (execution phase, which includes) exposing the pepper plant 10 to the target R:FR ratio by providing the device light 101. As described above, the present invention can also provide a method for cultivating pepper plants 10, wherein the method can include: (a) (sensing phase, which includes) determining a plant load-related parameter of the pepper plant 10 and providing an input signal, (b) (planning phase, which includes) determining a target phytochrome stable state based on the input signal and the plant load threshold, and (c) (execution phase, which includes) placing the pepper plant 10 in the target phytochrome stable state by providing the device light 101.

[0108] In an embodiment, the method proposed herein may include the following: (a) specifying an expected abortion rate or an expected plant load. Alternatively, these expected quantities are obtained from a model; (b) regularly measuring the abortion rate or plant load; (c) based on these expected quantities and the measurement of these quantities, adjusting the R:FR ratio in the device light 101 or in the daily integral of all light provided to the plants by adjusting (supplementing) the light in the R channel and / or FR channel of the device light 101: (i) in the case of an abortion rate above a first threshold or a plant load below a first threshold, increasing the R:FR ratio; (ii) in the case of an abortion rate below a second threshold or a plant load above a second threshold, reducing the R:FR ratio. The threshold may depend on the daily daylight integral. Alternatively: (i) in the case of an increase in plant load, reducing the R:FR ratio; (ii) in the case of a decrease in plant load, increasing the R:FR ratio.

[0109] Furthermore, the system may be based on the proposed method, including a feedback loop. In particular, red light may be applied primarily when daylight levels are low, such as before or at the beginning of the day, at the end of the day or after, or during cloud cover. Furthermore, in an embodiment, the preferred red wavelength may be in the range of 620-670 nm, such as 660 nm, and more particularly in the range of 620-640 nm, such as about 630 nm. The preferred far-red wavelength may be in the range of 720-740 nm.

[0110] In embodiments, the so-called phytochrome stable state (PSS) value may also be used instead of the R:FR ratio (a high R:FR ratio means a high PSS and vice versa).

[0111] Furthermore, instead of the abortion rate, the net fruit set rate can also be used (in the case of an increase in the abortion rate, the net fruit set rate decreases, and vice versa), etc., see also above. The net fruit set rate can be defined as the fruit set rate minus the fruit abortion rate.

[0112] refer to Figure 2 , curve L2 represents the change of plant load over time. In particular, Figure 2 Schematically depicted is how a cyclical pattern of net fruit set (referred to as flushing pattern) will result in a cyclical pattern of plant load and yield. However, a (more or less) constant plant load is desired, resulting in a constant yield, as represented by curve L1. This will occur if the net fruit set is constant, which in turn means that the abortion rate is constant. Note that flowering rate and fruit set may be temperature dependent. In particular, higher temperatures may result in a higher flowering rate and / or a higher fruit set rate. Therefore, in an embodiment, in particular in the planning phase, the control system may (be configured to) determine a target R:FR ratio (range) based at least in part on the (expected) ambient temperature of the pepper plant, such as based on an input signal, a plant load threshold and the (expected) ambient temperature.

[0113] Therefore, in practice, the plant load shows periodic fluctuations over time. What is desired is a constant plant load, which preferably exceeds the average value of the actual fluctuating plant load. Therefore, the abortion rate can be measured regularly. For example, it can be measured by labeling new fruit sets and then checking whether they are still present on the plant. The plant load can be measured by counting the number of fruits hanging on the plant. Measuring plant load may be easier than measuring abortion rate. Based on the measured abortion rate or plant load, etc., the ratio of R and FR in the (supplementary) device light (daily integral) provided to the plant can be adjusted, as represented by curve L3. This may result in a flatter yield, see the more desired curve L1. Time τ is indicated on the x-axis, and magnitude M (such as yield) is indicated on the y-axis.

[0114] For example, in the case where the plant load is above a first threshold, the R:FR ratio can be decreased. In the case where the plant load is below a second threshold, the R:FR ratio can be increased (the second threshold is lower than or equal to the first threshold). Figure 2 Depicted in diagram.

[0115] It may be desirable to provide more supplemental light on cloudy days than on sunny days to ensure a good balance for the crop and sufficient assimilate yields for plant and fruit growth. This means that, in general, in practice, the R:FR ratio in the daily integral of all light provided to the plant may be different on a cloudy day than on a sunny day (because the spectrum of supplemental light may generally be different from the spectrum of daylight). Therefore, in an embodiment, the above thresholds may depend on the daily integral of daylight.

[0116] In an embodiment, a feedback loop can be used that adjusts the R:FR ratio in the daily integral of the light provided to the plant to reduce fluctuations in the abortion rate or plant load. For example, as a first step, the system is initialized to reflect the grower's crop growth strategy (e.g., growing bell peppers at a certain plant density, desired net fruit set, or desired abortion rate, or desired plant load, desired temperature, etc.). Next, in a repeated cycle, the abortion rate can be measured. Alternatively, the plant load is measured (see also the above options). Next, a decision may be made. An example of such a decision is: decision A, where the abortion rate is higher than a first (abortion) threshold or the plant load is lower than a first (load) threshold; or decision B, where the abortion rate is lower than a second (abortion) threshold or the plant load is higher than a second (load) threshold. Next, an action may be taken. An example of such an action is: action A, where if decision A is true, the R:FR ratio is increased; or action B, where if decision B is true, the R:FR ratio is reduced. The feedback loop can be based on the well-known PID control principle, or on a machine learning model based on applied reinforcement learning.

[0117] The invention can also be implemented by dividing the horticultural space into two or more parts. By controlling the different temporal behavior of the light, the average yield can be made even more constant. For example, the crop cultivation area can be divided into n parts. An overall (more) constant yield can in principle also be obtained as follows: Divide the crop cultivation area into n (equal) parts. Use the method discussed in the above embodiments to gradually shift the phase of the periodic yield pattern of each part so that the yield pattern is out of phase by 360° / n. In particular, n is 2 or more.

[0118] Typically, the environment in a horticultural space, such as a greenhouse, may depend on the location in the horticultural space. For example, the temperature may not be uniform throughout the greenhouse. As a result, the abortion rate or plant load may not be consistent throughout the greenhouse. Furthermore, as a result, the fluctuations in abortion rate and plant load may be out of phase for different locations in the greenhouse. Therefore, in addition to the reasons mentioned above, it may be beneficial to divide the greenhouse into two or more sections and control the light in each section independently.

[0119] The term "plurality" refers to two or more. Those skilled in the art will understand the terms "substantially" or "substantially" and similar terms herein. The terms "substantially" or "substantially" may also include embodiments with "completely", "completely", "all", etc. Therefore, in an embodiment, the adjective substantially or substantially may also be removed. Where applicable, the term "substantially" or the term "substantially" may also refer to 90% or more, such as 95% or more, particularly 99% or more, even more particularly 99.5% or more, including 100%. The term "comprising" also includes embodiments in which the term "comprising" means "consisting of".

[0120] The term "and / or" specifically refers to one or more of the items mentioned before and after "and / or". For example, the phrase "item 1 and / or item 2" and similar phrases may refer to one or more of item 1 and item 2. The term "comprising" may mean "consisting of" in one embodiment, but may also mean "including at least the defined categories and optionally one or more other categories" in another embodiment.

[0121] In addition, the terms first, second, third, etc. in the specification and claims are used to distinguish between similar elements and not necessarily to describe a sequential or temporal order. It should be understood that the terms so used are interchangeable under appropriate circumstances, and that the embodiments of the invention described herein are capable of operation in other sequences than those described or illustrated herein.

[0122] During operation, an apparatus, device or system may be described herein - among other things. As will be clear to one skilled in the art, the present invention is not limited to methods of operation, or apparatus, devices or systems in operation.

[0123] It should be noted that the above-mentioned embodiments illustrate rather than limit the invention, and that those skilled in the art will be able to design many alternative embodiments without departing from the scope of the appended claims.

[0124] In the claims, any reference signs placed between parentheses shall not be construed as limiting the claim.

[0125] The use of the verb "comprise" and its conjugations does not exclude the presence of elements or steps other than those stated in a claim. Unless the context clearly requires otherwise, throughout the specification and claims, the words "comprises," "comprising," etc. should be interpreted in an inclusive sense, rather than an exclusive or exhaustive sense; that is, in the sense of "including but not limited to."

[0126] The article "a" or "an" preceding an element does not exclude the presence of a plurality of such elements.

[0127] The invention may be implemented by means of hardware comprising several distinct elements and by means of a suitably programmed computer. In a device claim, an apparatus claim or a system claim enumerating several means, several of these means may be embodied by one and the same item of hardware. The mere fact that certain measures are cited in mutually different dependent claims does not indicate that a combination of these measures cannot be used to advantage. In yet another aspect, the invention (therefore) provides a software product which, when run on a computer, is capable of implementing (one or more embodiments of) the method as described herein.

[0128] The present invention also provides a control system that can control a device, apparatus or system, or can perform the method or process described herein. Still further, the present invention also provides a computer program product that, when functionally coupled to a device, apparatus or system or run on a computer included in the device, apparatus or system, controls one or more controllable elements of such a device, apparatus or system.

[0129] The present invention further applies to an apparatus, device or system comprising one or more characterizing features described in the specification and / or shown in the attached drawings. The present invention further relates to a method or process comprising one or more characterizing features described in the specification and / or shown in the attached drawings.

[0130] The various aspects discussed in this patent can be combined to provide additional advantages. In addition, those skilled in the art will appreciate that the embodiments can be combined, and more than two embodiments can also be combined. In addition, some features can form the basis of one or more divisional applications.

Claims

1. A system (1000) for cultivating pepper plants (10), wherein the system (1000) comprises a light generating device (100) and a control system (300), wherein the light generating device (100) is configured to provide a device light (101) to the pepper plants (10), wherein the device light (101) comprises one or more of red light and far-red light, wherein the red light comprises one or more wavelengths in the range of 600-700 nm, and wherein the far-red light comprises one or more wavelengths in the range of 700-800 nm; wherein the system (1000) has an operable mode, wherein: - the control system (300) is configured to obtain an input signal, wherein the input signal is related to a parameter related to plant load of the pepper plant (10), the plant load being the number of fruits hanging on the plant, wherein the parameter related to plant load is selected from the group consisting of plant load, flowering rate, flower abortion rate, fruit setting rate and fruit abortion rate; - the control system (300) is configured to determine a plant load based on an input signal, and wherein one or more of the following apply: (i) the control system (300) is configured to compare the plant load to a lower plant load threshold, and if the plant load is below the lower plant load threshold, select a target R:FR ratio of red light to far-red light that is above a threshold ratio T; and (ii) the control system (300) is configured to compare the plant load to an upper plant load threshold, and if the plant load is above the upper plant load threshold, select a target R:FR ratio that is below a threshold ratio T, wherein the threshold ratio T is selected from the range of 10-25; - The control system (300) is configured to control the light generating device (100) to expose the pepper plants (10) to a target R:FR ratio.

2. The system (1000) of claim 1, wherein the system (1000) comprises a sensor system (200), wherein in an operational mode: - the sensor system (200) is configured to determine plant load related parameters of the pepper plants (10) and to provide relevant sensor input signals to the control system (300); - The control system (300) is configured to determine the plant load based on relevant sensor input signals.

3. The system (1000) according to any one of the preceding claims, wherein the control system (300) comprises a user interface (301), and wherein in an operational mode: - the user interface (301) is configured to receive user input regarding plant load related parameters of the pepper plants (10), and to provide relevant user input signals to the control system (300); - The control system (300) is configured to determine the plant load based on relevant user input signals.

4. A system (1000) according to any of the preceding claims, wherein the control system (300) is configured to determine a time derivative of plant load based on an input signal, and wherein one or more of the following applies: (i) the control system (300) is configured to compare the time derivative of plant load with a plant load time derivative threshold, and if the time derivative of plant load is above the plant load time derivative threshold, select a target R:FR ratio above a threshold ratio T; and (ii) the control system (300) is configured to compare the time derivative of plant load with a plant load time derivative threshold, and if the time derivative of plant load is below the plant load time derivative threshold, select a target R:FR ratio below a threshold ratio T, and wherein the threshold ratio is selected from the range of 13-17.

5. A system (1000) according to any of the preceding claims, wherein the plant load is a predicted plant load, and wherein one or more of the lower plant load threshold and the upper plant load threshold are selected based on a target yield, wherein the target yield includes one or more of fruit quantity, fruit quality, and fruit maturity time.

6. The system (1000) according to any of the preceding claims, wherein the plant load is a current plant load.

7. The system (1000) according to any of the preceding claims 2-6, wherein the sensor system (200) comprises a movable sensor device (210) configured to determine the plant load related parameter.

8. The system (1000) according to any one of the preceding claims, wherein the pepper plants are selected from the genus Capsicum.

9. The system (1000) according to any one of the preceding claims, wherein the control system (300) is configured to control the light generating device (100) to subject the pepper plants (10) to at least 5 mol / m 2 / d of light exposure, and wherein the target R:FR ratio is a daily target R:FR ratio of the device light (101).

10. A horticultural system (400) comprising the system (1000) according to any one of the preceding claims, wherein the horticultural system (400) comprises a horticultural space (410) for housing pepper plants (10), and wherein the system (1000) is configured to provide an equipment light (101) to the horticultural space (410).

11. The horticultural system (400) of claim 10, wherein the horticultural space (410) is configured to receive natural daylight (1), and wherein the device light (101) comprises a supplemental device light.

12. The horticultural system (4000) of claim 11, wherein the system (1000) is configured to provide supplemental equipment light during low natural lighting periods in the second half of the day, wherein during the low natural lighting periods, the photon flux density of natural daylight (1) is ≤ 500 μmol / m in the 400-700 nm region. 2 / s.

13. A method for cultivating pepper plants (10), wherein the method comprises: - obtaining an input signal, wherein the input signal is related to a parameter related to plant load of the pepper plant (10), the plant load being the number of fruits hanging on the plant, wherein the parameter related to plant load is selected from the group consisting of plant load, flowering rate, flower abortion rate, fruit setting rate and fruit abortion rate; - determining a plant load based on the input signal, and performing one or more of the following: (i) comparing the plant load to a lower plant load threshold, and if the plant load is below the lower plant load threshold, selecting a target R:FR ratio of red light to far-red light that is above a threshold ratio T; and (ii) comparing the plant load to an upper plant load threshold, and if the plant load is above the upper plant load threshold, selecting a target R:FR ratio that is below the threshold ratio T, wherein the red light includes one or more wavelengths in the range of 600-700 nm, and wherein the far-red light includes one or more wavelengths in the range of 700-800 nm, and wherein the threshold ratios are selected from the range of 10-25; - Exposing pepper plants (10) to a target R:FR ratio by providing plant light (101).

14. The method of claim 13, wherein the threshold ratio is selected from the range of 10-20, and wherein the method comprises one or more of: (a) if the plant load is below a lower plant load threshold, selecting a target R:FR ratio > 20; and (b) if the plant load is above a higher plant load threshold, selecting a target R:FR ratio < 10.

15. The method according to any one of the preceding claims 13-14, wherein the plant load is a predicted plant load, or wherein the plant load is a current plant load; wherein the method further comprises exposing the pepper plants (10) to natural daylight (1), and wherein the method comprises providing the device light (101) during periods of low natural lighting, wherein during the periods of low natural lighting, the photon flux density of the natural daylight (1) is ≤500 μmol / m in the 400-700 nm region. 2 / s, and wherein the target R:FR ratio is a daily target R:FR ratio; and wherein the method comprises using a system (1000) according to any one of the preceding claims 1-9 or a horticultural system (400) according to any one of the preceding claims 10-12.

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