Disinfection system and method for disinfecting crops

Abstract

The invention concerns a system for controlling pest infestation of crops, comprising one or more light sources that are particularly arranged in a grid like pattern, wherein the one or more light source is configured to emit UV radiation in a direction substantially different to a radiation direction for crop growth. A fog generator is configured to produce fog in a first volume covered by the UV radiation emitted by the one or more light sources, where the produced fog comprises a specified density and a specified range of droplet size; said fog scattering UV radiation emitted by the one or more light sources towards the crops. The first volume is distanced from the one or more light sources.

Description

[0001] DISINFECTION SYSTEM AND METHOD FOR DISINFECTING CROPS

[0002] The present invention concerns a system for controlling pest infestation of plants in closed rooms as well as a method for controlling pest infestation of plants in a horticulture environment .

[0003] BACKGROUND

[0004] Horticulture is becoming increasingly important in both the residential and commercial sectors . It allows for the highest possible yield on a small area with reduced use of water and nutrients . The enclosed spaces help to create a defined environment for the respective crops so that they can thrive optimally .

[0005] However, there is an increased risk of pest infestations to which the plants are exposed, which not only reduce the yield, but , in the worst case , can even lead to the complete destruction of the crops . In this regard and for the purpose of this application, the expression pest infestations or simply pest shall cover all types of animal pests , but also plant pests , bacteria, or fungi that pose a threat to crops . Animal pests include , but are not limited to insects , like aphids , beetles , bugs , fruit flies , and the like . Likewise , plant diseases , often caused by fungi , may include gray mold, cucumber mosaic virus , clubroot , late blight , all kinds of mildew, rust , and the like .

[0006] In a horticulture environment , pests and germs often lead to the development of diseases that can affect crop growth and quality, sometimes even more compared to natural environments . Common methods of pest control and disinfection include either harmful chemicals or difficult to control biological methods . Another approach stated in US 2009 / 0272029 and US 2018 / 0255709 is based on light and particularly UV light to irradiate the plants , thereby killing the pests and germs before they can cause a lot of harm .

[0007] However, it has been found that in a modern horticulture environment , the current method sometimes produces not the desired results and pest control is not sufficiently high enough . It is therefore an obj ect of the present invention to improve the existing approaches to enable a cheap , yet efficient way of pest control , which additionally does not provide a large risk to humans .

[0008] SUMMARY OF THE INVENTION

[0009] This and other obj ects are addressed by the subj ect matter of the independent claims . Features and further aspects , the proposed principles are outlined in the dependent claims .

[0010] The inventors now propose a different approach to ensure that UV radiation and more generally germicidal light for disinfection and controlling the biological and pest infestation of crops reach the upper portions of the crops as well as the lower portions thereof that are usually shadowed within a horticulture environment . In this regard, horticulture environment is usually referred to as the cultivation of plants in a predefined spaces such as gardens or greenhouses , as opposed to the field-scale production of crops characteristic of agriculture . It includes the cultivation of fruits , vegetables , nuts , seeds , herbs , sprouts , mushrooms , algae , flowers , seaweeds , and non-food crops such as grass and ornamental trees and plants . A horticulture environment may include soil for the plants to grow in but is not limited thereto and may also be implemented using purely hydroponics or any combination thereof .

[0011] For this purpose , the inventors propose a grid of ground-based light sources that emit germicidal radiation from the bottom into the upper hemisphere of the horticulture environment , e . g . along the crop' s growth direction . To ensure a uniform and substantial homogenous radiation pattern, a scattering medium is now inj ected into the atmosphere of the crop environment . Emitted germicidal radiation is scattered at the scattering medium and reflected back towards the crops , thereby ensuring that the emitted light reaches substantially all parts of the plants within a given volume of the horticultural environment . For the purpose of this application, the term scattering includes forward and backward scattering . The term reflecting is usually understood to encompass backscattering, although it should not be limited thereto .

[0012] The purpose of that scattering is to provide a homogeneous "blanket" or radiation of light covering parts of the greenhouse and horticulture farm that need to be disinfected . This includes , but is not limited to the crops , soil , or other growth media, as well as greenhouse equipment .

[0013] In some aspects , the ground-based light sources emit germicidal light in a direction that is different to the direction of the usual radiation for growing the crops . The scattering medium inj ected into the atmosphere scatters that light back towards the growing plants and crops of the horticulture farm. In some aspects , the light sources for emitting light suitable for growing the crop can be located between the crops . In such aspect , the light source emitting germicidal light may be arranged close to the other light sources and also emit germicidal light in substantially the same direction .

[0014] This will establish a full and uniform illumination and radiation of disinfecting light , whereas the spectrum, irradiance , and scattering can be adj usted to the desired needs .

[0015] The main advantage of such a proposal is the interoperability of providing a homogeneous blanket of radiation even in areas that are usually shadowed by the crops , when conventional overhead lighting systems are used . The scattering medium can be adj usted in height as well as in its scattering characteristics and strength, allowing for optimal irradiation strength based on the level of pest infestation . This not only increases safety for humans ( e . g . they can effectively walk and work within the horticulture environment during disinfection without being exposed to harmful ris ks ) , but also reduces the overall power consumption by only radiating the necessary areas and avoiding chemical agents .

[0016] In some aspects , a system for controlling pest infestation of crops is proposed, comprising one or more light sources configured to emit UV or energy-rich blue light . The one or more light sources are particularly arranged in a grid like pattern, although different patterns suitable for the respective applications can be used .

[0017] The one or more light sources may be configured to emit light of various wavelengths in accordance with the target application . For example , the wavelength range can span from UV-C light below 200 nm for disinfection purposes to blue light below 500 nm for pest and infestation control . Moreover, the one or more light sources can be arranged in certain regions , where the respective wavelength ranges are most suitable .

[0018] In accordance with the proposed principle , the one or more light sources are configured to emit light in a direction substantially opposite to a radiation direction for light used for crop and plant growth . The system now further comprises a fog generator configured to produce fog or mist in a first volume that is covered by the UV radiation when UV radiation is emitted by the one or more light sources . The fog being produced by the generator comprises a prespecified concentration and density and / or a pre-specified range of the droplet sizes . The fog and mist can contain pure water droplets but may also contain certain glycols or any other biologically degradable components .

[0019] In some aspects , additives are added during the creation of fog in order to control certain parameters of the fog, in particular, but not limited to droplet formation, droplet size , and evaporation rate . In some aspects , the fog generator utilizes those additives .

[0020] The fog within the first volume scatters the UV radiation emitted by the one or more light sources back towards the crops . To this extent , the produced fog acts as a scattering medium inj ected into the first volume above the growing crops for scattering the UV radiation coming from ground level back towards the crops and their fruit bodies , thereby producing a homogeneous blanket of light suitable for disinfection, pest control , and infestation control . In some aspects , the one or more light sources are located on a ground level of the space or on the substrate of the growing environment of the crops . If the various crops are located on different levels , it may be suitable to arrange the one or more light sources at the lowest level or in a similar manner as the respective level of crops to ensure that illumination and irradiation of the crops is achieved, preferably at their respective lower parts . Consequently, the one or more light sources can also be located below the portions of the crops and particularly below those portions which are specifically sensitive towards the pest , fungi , or bacteria to be controlled .

[0021] In this regard, the one or more light sources and may be configured to emit the respective UV or visible light in a second volume , wherein that second volume is located between the first volume and the respective ground level . Consequently, the scattering medium realized by a liquid scattering medium produced by the fog generator is located at a certain distance above the light emission surface of the one or more light sources . Said distance may be adj ustable by the fog generator . In some particular aspects , the fog is not only created above the crops or limited to a space above the crops , but actual generated in such way that it at least partially surrounds the crops or parts of it . This will increase irradiation levels in between the crops . It is understood that the fog particles are not only reflecting, but also forward scattering the light . Hence , a uniform radiation blanket is achieved by the scattering on the fog particles , which illuminates the crops from all sides .

[0022] In some aspects , the one or more light sources comprise a first plurality of light sources configured to emit light within a first wavelength range and a second plurality of light sources configured to emit light within a second wavelength range . The first and second wavelength ranges might be different or may only partially overlap each other . This provides light sources with adj ustable wavelengths as well as adj ustable intensities for more precise pest and infestation control and thus allows the creation of spectra optimized for the most effective pest and infestation control . Consequently, in some aspects , the one or more light sources may emit light below 200 nm wavelengths up to approximately 450 nm wavelength . In some aspects , the system may further comprise at least one second light source configured to emit visible light , particularly in the range between 400 nm to about 480 nm, which is suitable for pest and fungi to be exterminated . Said light may be emitted in a direction substantially opposite to a radiation direction of light , which is suitable for crop growth .

[0023] In some further aspects , the system may comprise at least one third light source configured to emit visible light , particularly in the range between 660 nm to 780 nm in a direction substantially opposite to a radiation direction for crop growth . Such light in the visible red range of the spectrum may complement the light for growing the crop itself . In this regard, the system may further comprise a fourth light source configured to emit infrared light , in particular in the range above 780 nm in a direction substantially opposite to the radiation direction of light for crop growth . In some aspects , the air temperature in the environment close to ground level is adj usted using heating or cooling elements , i . e . warm water, Peltier elements , heaters , and the like .

[0024] In a further aspect , the system may comprise at least a fifth light source configured to emit visible light suitable for crop growth . Said at least fifth light source is usually arranged above the first and second volumes and may be directed towards the ground level . However, in some horticulture environments , a plurality of such fifth light sources can be arranged to produce a more homogenous irradiation of light suitable for crop growth, although a main direction should be preserved to ensure the crop grows in a preferred direction . This does not necessarily need to be the direction perpendicular to ground level or earth' s surface . However , the one or more light sources are supposed to be arranged in such a way that the UV radiation emitted by such light sources may follow the growth direction of the crops . In this regard, the radiation characteristics of the one or more light sources as well as the other light sources mentioned above may follow in some aspects a Lambertian emission characteristic to ensure a uniform and homogeneous radiation pattern throughout the volume around and above the crops . Depending on the application, i . e . with a desired deeper intrusion into the fog , a source with a narrower gaussian emission characteristic can be used . By this it is also possible to increase the distance between the fog layer and the UV radiation source . A reduction of emitting centers per area of greenhouse space can be achieved through the use of high-power uniform or batwing-shaped sources .

[0025] Some aspects concern the fog generator and the scattering medium . The scattering of the light provided by the one or more light sources is realized by a liquid scattering medium being part of the fog itself .

[0026] The first volume may comprise a certain amount of water and / or certain glycol droplets or other components that are dispersed within the first volume as an artificial mist or fog with a controlled, yet adj ustable droplet size and droplet concentration or density . The amount of scattering is determined by the droplet concentration and density as well as the droplet size , while the volume and in particular, the distance between the created fog and the ground level are controlled primarily by its temperature difference between the existing atmosphere and between the two levels . Consequently, the first volume can comprise a certain temperature , which is different from the surrounding environment and particularly close to ground level . This will somewhat concentrate the droplets in a more definable volume above ground level ( or if the fog is generated at ground level will concentrate the water droplets around the crops ) . This volume then comprises an increased concentration of small liquid droplets like the above-mentioned components . In this regard, the ground level and floor surface can be set up with the respective heating elements to allow a more controllable distance between the first volume above ground level and the ground level itself . In this regard, the area between the ground level and the first volume is also referred to as the "second volume . In some aspects , the fog generator comprises a plurality of ultrasonic transducers , wherein at least one of the frequency and the amplitude of the ultrasonic transducers is adj ustable . Hence , the density of the water or liquid droplets as well as their sizes can be controlled and adj usted by the frequency and amplitude of the ultrasonic transducers . The ultrasonic transducers can be arranged at various different locations within the environment and particularly within the first volume or close by . Water or liquid droplets are sprayed into the first volume by the ultrasonic transducers .

[0027] In some aspects , the transducers may be arranged on the same level as the one or more light sources , for example , parallel to them in a grid like structure . In this regard, the transducers are configured to create a foggy or misty environment closer to or adj acent to the one or more light sources . By heating the ground level or at least generating a different temperature at ground level compared to some air layer above ground level , one may cause the mist and fog to rise to a certain level . In some other aspects , the transducers are arranged above the one or more light sources in the direction of crop growth, such that the water or liquid droplets provided by the ultrasonic transducers are generated in a volume above the light sources . Consequently, various combinations are possible to create a misty and foggy environment partially around the growing crops and / or above them . This will allow for a homogeneous radiation level within the volume in which the crops are growing .

[0028] In some other aspects , the fog generator may comprise one or more evaporative fog machines , ultrasonic fog generation units , and / or misting units , particularly when implemented with integrated chillers . The misting units are configured to inj ect or spray liquid droplets in the form of fog substantially from one or more sides into the first volume . Alternatively, the misting units can be configured to spray the water droplets from the top towards the crops . In this regard, the misting units may also comprise some irrigation functionality to water the crops . Furthermore , the misting units may be arranged with additional cooling elements in some aspects to spray water droplets with a previously specified density and droplet size above the one or more light sources into a predefined first volume . Any integrated chiller unit or cooling element supports the adj ustment of different temperatures for the fog in comparison to the surrounding environment , thereby creating a foggy volume above the crop plants to ensure scattering of the light emitted by the one or more light sources back towards the second volume in which the plants are growing .

[0029] In a further aspect , the system may also comprise one or more heating or chilling elements arranged on the ground level adj acent to the one or more light sources to provide a certain and defined first temperature within the volume between the ground level and the first volume . Said chilling elements can be provided by water pipes . In hydroponic cultures , those water pipes can also be used to provide nutrition to the crop roots . The temperature close to the ground level and within the second volume can be different and particularly higher than the respective air temperature of the first volume . Consequently, the different temperatures in layers of the horticulture environment or volumes thereof provide a controllable adj ustment of the distance of the foggy first volume to the ground level .

[0030] In some further aspects , the system comprises a control unit which is configured to control the one or more light sources as well as the fog generator .

[0031] Based on certain data, simulations illustrate that 0 . 5 W of radiation or even less applied in bursts of 60 seconds is sufficient to disinfect or at least control the pest and infestation in an area of 1 m2and 0 . 3 m in height . This value translates to 30J / m2of radiation . The radiation is sufficient to reduce the most common pathogens , including viruses , bacteria and protozoa , to an acceptable level .

[0032] Nevertheless , the system according to the proposed principle may be configured to adj ust the radiation level , the exposure time as well as the wavelengths by controlling the respective one or more light sources to affect fungi and insects if required . As stated above the one or more light sources may comprise such functionality and control option . In addition or alternatively, the control unit may be configured to control the fog generator by adj usting the droplet concentration or density of the produced fog within the first volume and the environment . Likewise , the control unit can be configured to control the fog generator to adj ust the droplet size of the produced fog . As stated above , the fog generator may comprise such functionality and control option .

[0033] In some further aspects , heating elements are provided that are configured to adj ust the temperature within the first and / or second volumes . Consequently, the control unit may be coupled to such heating elements to adj ust the temperature in those respective volumes independently and separately from each other . Hence , different temperatures at different levels within the horticulture environment may be reached . By doing so , the control unit is indirectly configured to control the fog generator in such a way that the distance of the first volume from the ground level can be adj usted .

[0034] Hence , radiation for the pest and infestation control can be maximized and optimized to predetermined heights from ground level to , for example , specifically irradiate portions of the crops , i . e . only the leaves thereof . An intensity of the emitted light is controllable by the control unit adj usting the emission of the one or more light sources or switching them individually on or off when those of light sources are arranged in a grid like structure . In some aspects , the light sources are configured to provide different wavelengths of the emitted light . Consequently, the control unit is configured to adj ust the wavelength of the emitted light . By properly controlling the light source , the light emission coverage within the previously specified space can be adj usted by controlling the one or more light sources by the light source , i . e . selectively switching some of them on or off or adj usting its power . Consequently, one may irradiate only certain areas within a larger horticulture environment , namely those that are affected, while areas with plants not affected by pests or infestations are not irradiated . This does not only reduce power consumption, but also prevents viruses , bacteria and other pests from becoming immune to the radiation levels .

[0035] Some further aspects relate to a method for controlling pest infestation of crops in a horticulture environment . The method comprises the step of providing one or more light sources in a horticulture environment at a level on or below a top portion of the crops growing in said environment . The one or more light sources are configured to emit UV and / or blue light , with an emission being substantially directed along the growth direction of the crops . The crops are arranged on a level referenced to a ground level , although a single common level is not required . Rather, certain crops can be stacked so that crops are growing on different levels within the horticulture environment . For example , hydroponic growth on various stacking levels is possible in such environments . Consequently, the one or more light sources are configured such that they are emitting light either from the bottom of the respective crops or from below the respective top portions thereof .

[0036] Further in accordance with the method, a fog is created in a first volume that is covered by UV radiation when such light is emitted by one or more of the light sources . The foggy environment in the first volume comprises droplets of a specific size or size distribution with a specific density in the first volume . In some aspects , said density is between 0 . 01 volume-% to 2 . 5 volume-% and in particular between 0 . 1 volume-% to 1 . 5 volume-% . In accordance with the proposed principle , radiation is emitted by the respective one or more light sources towards the first volume . A portion of the emitted light will irradiate the crops from below and its sides as well , while a different portion of the light emitted by the one or more light sources is scattered back by the water droplets in the fog in the first volume towards the crops , thereby irradiating the crops from the top . Consequently, the proposed method generates a uniform and homogeneous blanket of light capable of irradiating the crops from the various sides at once , without overly shadowing large areas of the crops ( if at all ) .

[0037] Certain aspects , like adj usting the light intensity, as well as the light wavelength can change the incident power depending on the volume and environment , in which the crops are growing and are selected based on the desired application . Likewise , a fog density as well as droplet size enable a stronger back scattering and reflection of the light being emitted towards the first volume .

[0038] In some aspects , the step of creating a fog in the first volume comprises creating the fog located above the one or more of light sources and particularly distanced to those light sources . Consequently, the fog is created in an area , which may contain only portions of the crops and in some aspects , it is even created above the crops and plants within the environment . This will ensure that germicidal radiation is scattered above the top portions of the crops and thus irradiates the crops from the top . In some aspects , the step of creating a fog in a first volume comprises creating a fog in such a way that a second volume is generated between the one or more light sources , e . g . between the ground level and the first volume .

[0039] In this regard, the fog density in the first volume is at least five times higher compared to a fog density and water droplet density in the respective second volume , or in the area located between the one or more light sources and the foggy environment . In other words , the method proposes to create a foggy environment separated from surroundings and particularly separated from the one or more light sources by at least an additional layer of air in between .

[0040] Said air layer may comprise a different temperature compared to the air temperature in the first volume and the foggy environment to ensure the creation and distribution of the water droplets within the first volume having a higher density than a potential droplet density in the surrounding areas . The temperature difference can be generated by heating the ground level for instance , by providing respective infrared light sources , as well as cooling the air layer within the first volume . A combination of heating and cooling the various air layers is possible . Consequently, a temperature difference is generated in a first air layer corresponding to or being included in the first volume , as well as a second pair layer between the first volume and the one or more light sources . The temperature within the first air layer that is within the first volume is generally lower than the air temperature within the second air layer .

[0041] The fog can be created by various means , including for example spraying water or any other liquid droplets from the side into the first volume . This is useful for creating large areas of foggy environment . As an alternative , water can also be sprayed from level on or below a top portion of the crops into the first volume using for instance , transducers or any other electromechanical forceproducing devices . In certain aspects , the water can be dispensed from above the crops into the first volume . In this regard, the liquid droplets can comprise a size of approximately 2 pm to about 50 pm, for example approximately 10 pm . Apart from water, also certain alcohols or other liquids can be used, which may also provide an additional functionality, like for instance certain biodegradable glycols , further reducing pests and infestations on the plants .

[0042] By switching on or off , thus deactivating certain areas within a horticulture environment , the overall power consumption as well as resource consumption can be reduced . In addition, only those areas with pests and infestations are irradiated enabling humans to work in other areas simultaneously .

[0043] The proposed system and method provide a highly effective and efficient approach in comparison to traditional overhead or intercrop disinfection systems , whether they are light-based or rely on chemicals . The proposed system and method circumvent shadowing issues and ensure complete irradiation . Still , high flexibility is maintained s only specific parts of the crops , or the growing environment can be targeted, keeping wasted energy to a minimum. Likewise , the system can be easily adj usted to a specific target , either by changing the irradiation level using different fog concentrations , particle size or emitting power of the light sources or the irradiation coverage . Adj usting the active wavelength band aims to target specific pests , germs , or fungi .

[0044] Safety measures are maintained because a large blanket of targeted, low intensity radiation is safer than high-intensity germicidal spotlights . No potentially harmful chemicals or invasive biological agents are being used by the proposed principle . In particular, irradiance at critical locations ( eyes , exposed skin, etc . ) is kept low .

[0045] SHORT DESCRIPTION OF THE DRAWINGS

[0046] Further aspects and embodiments in accordance with the proposed principle will become apparent in relation to the various embodiments and examples described in detail in connection with the accompanying drawings in which

[0047] Figure 1 shows a working principle of a system according to some aspects , the proposed principle ;

[0048] Figure 2 illustrates some aspects , the working principle in accordance with some aspects , the invention;

[0049] Figures 3A to 3C illustrate some simulation results for less than 0 . 5W of radiation a simulated volume of 1x1x0 , 3m in accordance with some aspects , the proposed principle ;

[0050] Figure 4 illustrates a schematic view a first exampleof a system for controlling pest infestation of plants in accordance with some aspects , the proposed principle ;

[0051] Figure 5 shows a schematic view a second exampleof a system for controlling pest infestation of plants in accordance with some aspects , the proposed principle ; Figure 6 illustrates various steps of a method for controlling pest infestation of plants in accordance with some aspects of the proposed principle .

[0052] DETAILED DESCRIPTION

[0053] The following embodiments and examples disclose various aspects and their combinations according to the proposed principle . The embodiments and examples are not always to scale . Likewise , different elements can be displayed enlarged or reduced in size to emphasize individual aspects . It goes without saying that the individual aspects , the embodiments and examples shown in the figures can be combined with each other without further ado , without this contradicting the principle according to the invention . Some aspects show a regular structure or form . It should be noted that in practice slight differences and deviations from the ideal form may occur without , however, contradicting the inventive idea .

[0054] In addition, the individual figures and aspects are not necessarily shown in the correct size , nor do the proportions between individual elements have to be essentially correct . Some aspects are highlighted by showing them enlarged . However, terms such as "above" , "over" , "below" , "under" "larger" , "smaller" and the like are correctly represented with regards to the elements in the figures . So it is possible to deduce such relations between the elements based on the figures .

[0055] Figure 1 illustrates an embodiment of a schematic principle in accordance with the invention . The schematic illustrates a horticulture environment or another similar application, in which a plurality of crops ( not illustrated herein) is growing on a ground level 40 . Certain light sources provide radiation for growing the crops . Nutrition and water are added to the crops either along the ground level 40 but can partially also be provided from the side or from above . To this extent , the crops can be grown on conventional ground levels using soil and other solid material , but also on hydroponic structures , in which the roots of the crops are embedded and fed with respective water and nutrition . The top part of the crops , also referred to as plants , are usually growing the towards the light provided by elements referred to as sun light sources . Said sunlight sources resemble either sunlight or provide a certain spectrum which has been found particularly suitable for growing crops to optimize the respective yield .

[0056] Although only a small area of approximately Im2to 2m2is illustrated herein, one may note that the shape of the environment as well as its size can be different . In particular, some horticulture environments comprise large areas of several 100m2or more . They are divided into smaller subareas to individually provide light , water , nutrition and other depending on the crops growing there .

[0057] Under normal circumstances , any crops and plants are subj ect to potential diseases , bacteria , fungi , viruses , protozoa , insects and pests , which reduce the yield and can even result in severe damage to the plants within the horticulture environment . The expression pest infestation shall summarize the above-mentioned numeration for simplicity purposes but is not limited to those nor restricted to its specific meaning . For this purpose , pest infestation control for the crops against some of the above , but preferably all of them is required . While chemical means have been found suitable , they usually tend to address only one or two of the above-mentioned issues and also produce a lot of waste , or are expensive in its application .

[0058] The inventors propose a system for controlling pest infestation, in which a foggy environment 20 is generated in a specific volume above the growing crops . The foggy environment 20 can either reach from the ground level 40 to a certain height H or be generated at a certain distance from the ground level . The latter situation is depicted in Figure 2 . In any case , the foggy environment 20 is created in a respective volume and comprises liquid droplets of a certain size , as well as a certain concentration or density .

[0059] Size and density can be adj usted in accordance with the proposed principle to define and generate a proper scattering medium for light emitted by one or more respective light sources 30 . In contrast to the light sources providing the radiation for crop growth, light sources 30 are configured to emit UV radiation, blue light , and generally speaking light with a larger photon energy than the usual radiation light for crop growth . Furthermore , the light sources 30 are located adj acent to the ground level 40 or are embedded directly on the ground level . Their radiation characteristics follow Lambertian characteristics , resulting in an emission of light from the bottom a towards the top .

[0060] As a result of this arrangement , the crops growing in the respective horticulture environment and volume as depicted in Figure 1 will be irradiated from the bottom with high energy photons suitable for disinfection or pest control . To ensure a homogeneous and uniform radiation of such light , the foggy environment 20 acts as a scattering medium for the light provided by light sources 30 . The UV radiation will be partially scattered at the liquid droplets back to the crops , thereby irradiating the crops not only from the bottom but also from the top and from the sides . The scattering forms a uniform light blanket reaching various portions of the crops which are otherwise shadowed by conventional radiation techniques .

[0061] Figure 2 illustrates a side view of another embodiment of the proposed principle . In this embodiment , the ground level 40 provides not only the respective soil and supporting structure for the crops to grow, but also heating and temperature elements 41 . A plurality of transducer elements 25 is arranged in a grid like structure with adj acent light sources 30 adj acent to it . The transducers are configured to provide a misty environment of water droplets 26 or other droplets of liquid medium, wherein the density of those droplets in the overall volume above the transducers as well as the droplet size is given by the operating frequency and amplitude of the transducers 25 . The water 26 is sprayed into the above environment . The transducers 25 generated liquid droplets which are moving up towards volume VI , an area that is cool thereby creating a foggy environment 20 with a plurality of water droplets or liquid droplets 27 . The thickness and size of volume VI can be adj usted . The foggy volume 20 is created at a distance above the ground level 40 and due to an equal distribution of the transducer comprises a substantially uniform density .

[0062] The distance can be adj usted by the temperature difference between the ground level and the temperature within volume VI . More particular, one can define a second volume V2 in between the first volume and the ground level , whereas the height of volume V2 is substantial compared to the above-mentioned distance between volume VI and ground level . Volume V2 usually contains the crops in this embodiment , and only the uppermost parts if at all of the crops reach into volume VI . In other words , foggy environment 20 is preferably created above the growing crops to ensure that germicidal radiation scattered from that foggy environment 20 reaches the upper side of the growing crops .

[0063] By emitting UV radiation or high energy radiation using the one or more light sources 30 placed adj acent to the transducers 25 , a uniform and homogeneous blanket of light is created, suitable for a disinfection the top and bottom side of the growing crops . The existing layer of fog 20 can subsequently be used to water the crops or generate an environment of a specific humidity after radiation is conducted .

[0064] It has been found that there is a radiation dose of 0 . 5 W applied in bursts of 60 seconds is sufficient to disinfect and clear crops growing in an area of approximately 1 m * 1 m from common pathogens , including viruses , bacteria , and protozoa . By changing the density of the foggy environment 20 and the water droplets 27 within the volume VI as well as the size thereof , one can change the amount of back scattering of the radiated light by the one or more light sources 30 . In this regard, Figures 3A to 3C illustrate a proof of concept through a simulation setup showing a plant growing environment with a ground surface area of Im2and with different water droplet concentrations . More particularly, Figure 3A illustrates the simulation result for an irradiance in W / mm2for a water droplet concentration of 0 . 01 volume- % . The illustrated radiation level (W / mm2) is given for an illumination of four light sources being placed in a square within said area and radiating UV radiation . As indicated by the low droplet concentration of 0 . 01% in the given volume , the overall radiation level is approximately l , 35e-8 W / mm2or larger throughout said area, with this level being reached at the borders of the area . Closer to the light sources and the centre of the simulated area, the irradiance level increases to about 1 . 8 e-7 W / mm2. With an increase in water droplet concentration to 0 . 1 volume-% illustrated in Figure 3B, the irradiation level , particularly within the confined area between the four light sources increases as well . This is due to the larger scattering . The irradiation level is about 5e-7 W / mm2in the central portion with the lowest radiation level being at 6 . 2e-8 W / mm2and the largest irradiation level at 1 . 7e-6 W / mm2centrally over the light sources themselves .

[0065] Figure 3C illustrates the water droplet concentration at about volume-1% . The irradiation level across the simulated area further increases , reaching from 2 . 4e-8 W / mm2to approximately 1 . 27e-5 W / mm2. In comparison to the slightly reduced water droplet concentration illustrated in Figure 3B , it becomes apparent that the overall irradiation level seems to be now more uniform and homogeneous ( apart from a smaller central area around the light sources ) at an irradiation level of approximately 2 . 4e-8 W / mm2. The droplet size is approx . 10pm with a gaussian distribution . The increased fog density ensures a homogenous light blanket over the area with sufficiently large irradiation levels to achieve the desired disinfection . By changing the light intensity of the light sources this irradiation level can be further increased if needed .

[0066] Figure 4 illustrates an embodiment of a system for controlling pest infestation in a horticulture environment .

[0067] The system is arranged within a ground substrate that also contains locations suitable for crop growth 120 . As illustrated therein, the horticulture environment is configured to grow a variety of the different plants and crops therein . Ground level 40 comprises areas of soil as well as other portions including a plurality of transducers 25 as fog generators with light sources 30 arranged in a grid size structure . The transducers as well as the light sources comprise a defined distance from each other . While light sources 30 and transducers 25 are located adj acent to each other in this embodiment , one may note that such an arrangement is not necessary . Rather, the fog generator and the light sources can be distributed over the respective areas .

[0068] The locations of the light sources 30 are selected in such way that a homogeneous light field is generated within the horticulture environment . The light sources are placed such that they are not strongly shadowed by the planted crops to ensure illumination into volume 20 . Likewise , the transducers configured to provide a misty fog within the volume 20 are located accordingly at positions that will enable the creation of a uniform mist and fog with a homogeneous density of liquid droplets into the foggy environment 20 . In this embodiment , the foggy environment 20 is located from ground level 40 to a certain height , although depending on various parameters like temperature , such a volume can be set differently .

[0069] A plurality of pipes 28 is connecting the ultrasonic transducers with each other . The pipes 28 can support temperature adj ustment at ground level , for example by providing cold water for chilling or warmer water for heating the ground level accordingly .

[0070] Volume 20 is filled by water droplets 27 with a predefined and adj ustable density and droplet size using the transducers 25 thereby creating the foggy environment in operation of the system. For this purpose , the transducers are excited with a specific frequency and amplitude , thereby creating a plurality of water droplets 27 , which are pushed into volume 20 and universally dispensed therein . The droplet size may range from a few hundred nanometers to approximately 50 pm, although in different sizes are generally possible . In some examples , the droplet size is appr . 10pm . The light sources 30 are implemented as a plurality of light emitting diodes are configured to emit light in the UV spectrum as well as in the blue visible spectrum. The light sources control pest infestations and disinfect the crops . In operation, the environment is radiated by the respective light sources having an Lambertian emission characteristics . The emitted light will irradiate the crops from below direct . Portions of the emitted light will also be scattered by the water droplets 27 in the foggy volume back towards the planted crops . As a result thereof , a uniform and homogeneous light field is generated irradiating the crops and plants from all sides and thereby killing viruses , bacteria , pathogens , and pests 100 to about certain sizes .

[0071] Figure 5 illustrates the second embodiment for controlling and reducing pest infestation 100 in a horticulture environment . Similar to the previous embodiment , a plurality of different crops 120 is placed on the ground level 40 with a plurality of light sources 30a arranged in between in a grid like structure . In contrast to the previous embodiment , in which solid-state devices are used, light sources 30a are implemented as gas-discharge germicidal light sources . Light sources 30a provide a uniform emission characteristic for UV radiation down to UV-C spectrum into the volume V2 directly next to the crops as well as above the corps into volume VI .

[0072] A misting unit 25a is arranged on one or more side walls of the horticulture environment spaced apart from the ground level 40 by a certain distance . The misting unit 25a is configured to provide water droplets 27 of a certain density and size into the volume VI to create a foggy environment 20 spaced apart from the ground level 40 by a certain distance .

[0073] The volume VI is also chilled by a respective chiller device 29 arranged close to the misting unit 25a . The chiller 29 causes the air temperature within said volume to drop causing two or more layers of air being generated above ground level , whereas the different layers comprise different temperatures . The misty unit 25a provides water droplets 27 , which are now concentrating in volume VI due to the temperature difference , creating the fog layer 20 . Properly choosing temperature , droplet density and size creates layers of fog hovering above the ground level in a certain distance .

[0074] As in the previous embodiments , the water droplets 27 within said volume VI act as a scattering medium for the light emitted by a light source 30a . As a result , the light from light sources 30a is scattered back and reaches the upper portion of the crops 120 , wherein as portion of the light within the volume V2 below the volume VI directly illuminates the bottom side and other parts of the crops . Thus , a homogeneous light field is generated with only very small portions , -if at all being shadowed .

[0075] By controlling the amount of irradiation as well as the wavelength, various pest 100 and infestation control setups can be achieved . Furthermore , it is possible to selectively switch on and off the various light sources , particularly in cases , in which pest infestation occurs only at a specific location and not in the overall horticulture environment . Power consumption is thus reduced, and humans can work in other areas while simultaneous infestation control takes place .

[0076] The thermal balance provided by the chiller 29 provides a cooled fog within the volume VI , whereas the ground level can comprise a different temperature and particularly a higher temperature . This allows for stable adj ustment of the cooled fog within a certain distance from the ground level . In particular, it is possible to change that distance , thereby compensating for the growth of the respective crops .

[0077] Finally, the ground level itself can comprise a slightly reflective material , further enhancing and improving the homogeneous light field in the second volume . The layer thickness of the foggy layer 20 itself , is approximately in the range between 20 cm to 40 cm with a liquid density in air ranging from about 0 . 01 volume-% to approximately 1 volume-% . A typical droplet size may be in the range between 3 pm to 30pm, in particular about 10 pm. The droplet size may vary . Furthermore , a certain distribution of droplet size is possible , as well as a certain distribution in water vapor density . Apart from water being used as a fog material , other liquids are suitable as well , for example , those based on alcohol , e . g . propylene glycol or glycerol . This comprises a further benefit of being a biologically degradable disinfectant , further killing pathogens which may have survived the disinfection by the irradiating UV radiation .

[0078] Figure 6 illustrates some aspects of a method for controlling pest infestation of crops in a horticultural environment in accordance with the proposed principle . A horticulture environment , in this method, comprises a plurality of different plants and crops . These crops are planted along a single level , referred to as ground level but can also be stacked onto various level in a staircase like manner . Depending on the crop size , the crops can also be stacked on top of each other, for example , if hydroponic systems are used and the crops themselves are not growing overly large . This will allow a highly dense horticulture environment , in which crops are planted on the various different levels .

[0079] In all of these cases , a plurality of light sources is located to provide light with a spectrum resembling sunlight or a light spectrum suitable for plant growth . Such light sources are usually arranged above the crops but can also be located in a position to provide full light coverage .

[0080] Likewise , a plurality of light sources configured to emit UV or blue light is located close to ground level to irradiate the crops mainly from the side and from below thereby reaching the underside of the respective plants . Providing UV radiation from above may also help, but with denser plants or plants with larger leaves , such UV is often shadowed by the leaves and does not reach the ground level or the underside of the leaves . Those light sources emit light with a higher photon energy than what is used for plant growths . This light is mainly used for pest control and disinfection of crops and plants and reduction of infestations like viruses , bacteria ' s and approaches surface and the like . Referring now to step S2 . To provide a uniform and homogeneous light blanket irradiating various parts of the crops from above , the side , as well as from the bottom or underside , the method now proposes to create a foggy environment above the crops by having an air layer in between the light sources and the foggy environment .

[0081] The distance between the foggy environment and the respective ground level should be adj usted such that the main portions of the crops ( i . e . the digestible fruits ) are growing within said air layer . Hence , the fruit bodies can therefore be directly irradiated by the light sources .

[0082] It is useful to place only a small portion of the crops and their top parts of within the foggy environment to ensure a full irradiation of the overall crops from all sides . The foggy environment is created in step S2 by spraying water droplets into a specific area, which comprises preferably at a lower temperature than the surrounding volume . This will somewhat contain the water droplets within the predefined volumes long enough for the subsequent irradiation step . The water density within that volume reaches from 0 . 01 volume-% to approximately 2 . 5 volume-% , although higher values can be used . Generally speaking, the water density is significantly smaller in areas below the foggy environment , such that the light emitted by the light sources is scattered by the foggy environment and not by the water droplets in between .

[0083] Light is now emitted by the one or more light sources irradiating partially the crops the directly and partially being scattered by the foggy environment towards the upper side of the crops . Consequently, and uniform and homogeneous light blanket is generated, irradiating the crops from all sides without leaving substantial parts of the crop and its fruit body in shadow .

[0084] The proposed approach enables pest infestation control using light and water only, whereas the latter can be further used for watering the crops or setting the humidity levels within the horticulture environment .

[0085] LIST OF REFERENCES

[0086] 10

[0087] 20 foggy environment 25 transducer

[0088] 25a misty environment

[0089] 26 sprayed water

[0090] 27 droplets

[0091] 28 pipes 29 chilling unit

[0092] 30 , 35 light source

[0093] 40 ground level

[0094] 41 heating element

[0095] 100 pest 120 crops

[0096] VI first

[0097] V2 Volume

Claims

CLAIMS1 . System for controlling pest infestation of crops , comprising :One or more light sources that are particularly arranged in a grid like pattern, wherein the one or more light source is configured to emit germicidal light , in particular UV radiation in a direction substantially different from and / or opposite to a radiation direction for crop growth; a fog generator comprising a plurality of ultrasonic transducers , wherein at least one of frequency and amplitude of the ultrasonic transducer is adj ustable , configured to produce fog in a first volume covered by the germicidal light emitted by the one or more light sources , where the produced fog comprises a specified density and a specified range of droplet size ; said fog scattering germicidal light emitted by the one or more light sources towards the crops .2 . System according to claim 1 , wherein the one or more light sources are located on a ground level of a closed space ; or wherein the one or more light sources are located below upper portions of the crops .3 . System according to any of the preceding claims , wherein the one or more light sources are configured to emit germicidal light in a second volume , said second volume located between the first volume and a ground level .4 . System according to any of the p: 'eceding claims , wherein the one or more light sources comprises a first plurality of light sources configured to emit light within a first wavelength range and a second plurality of light sources configured to emit light within a second wavelength range , wherei the first and second wavelength range are different and / or wherei the first and second wavelength range overlap only partially .5 . System according to any of the preceding claims , further comprising at least one of :- at least one second light source configured to emit visible light , in particular in the range between 400nm to 480nm, suitable for suitable for pest and fungi control in a direction substantially opposite to a radiation direction for crop growth; at least one third light source configured to emit visible light , in particular in the range between 660 nm to 780 nm in a direction substantially opposite to a radiation direction for crop growth;- at least one fourth light source configured to emit infrared light , in particular in the range above 780 nm in a direction substantially opposite to a radiation direction for crop growth;- at least one fifth light source configured to emit visible light suitable for crop growth, wherein the at least one fifth light source is arranged above the first and / or second volume .6 . System according to any of the preceding claims , wherein the plurality of ultrasonic transducer is arranged on the same level as the one or more light sources .7 . System according to any of the preceding claims , wherein the fog generator comprises one or more misting units , particularly with integrated chiller configured to inj ect fog substantially from a one or more sides into the first volume .8 . System according to any of the preceding claims , further comprising one or more heating element arranged on a ground level to provide a first temperature within a volume between the ground level and the first volume , wherein the first volume comprises an air temperature below the first temperature .9 . System according to any of the preceding claims , wherein the one or more light sources comprises at least one of :A light-emitting diode , in particular a UV LED;A laser diode , in particular a UV laser diode ; andA gas discharge lamp , in particular a low-pressure mercury vapor lamp .10 . System according to any of the preceding claims , further comprising a control unit that is configured to control the one or more light source and the fog generator to adj ust at least one of : A droplet concentration and / or density of the produced fog ; A droplet size of the produced fog ;A temperature within the first volume ;A temperature within the second volume ;A distance of the first volume from a ground level ;An intensity of the emitted light by the one or more light sources ;A wavelength of the emitted light ; the germicidal light emission coverage within a pre-specified space .11 . Method for controlling pest infestation of crops in a horticulture environment , comprising the steps of : providing, at a level on or below a top portion of crops in a horticulture environment one or more light sources configured to emit one of UV and blue light with an emission direction in growth direction of the crops ; creating a fog in a first volume that is covered by germicidal light when emitted by the one or more light sources , said fog comprising droplets of a specific size or size distribution with a density in the first volume between 0 . 01 volume-% to 2 . 5 volume-% and in particular between 0 . 1 volume-% to 1 . 5 volumeemitting one of UV and blue light by the one or more light sources towards the first volume .12 . Method according to claim 11 , wherein the step of creating a fog in a first volume comprises creating the fog located above one of the one or more light sources and / or the crops within the environment ; and / or wherein the step of creating a fog in a first volume comprises creating the fog such that a second volume is generated between the one or more light sources and the first volume that comprisesa fog density that is reduced by at least a factor of 5 compared to a fog density in the first volume ; and / or wherein the fog is created above the crops .13 . Method according to any of claims 11 to 12 , further comprising : generating a temperature difference in a first air layer corresponding to or being included in the first volume and a second air layer between the first volume and the one or more light sources , wherein the air temperature in the first air layer is generally lower than the air in the second air layer .14 . Method according to any of claims 11 to 13 , wherein creating a fog in a first volume comprises at least one of : spraying water or other liquid droplets from a side into the first volume ; dispensing water or other liquid droplets from above the crops into the first volume ; and spraying water or other liquid droplets from a level on or below a top portion of crops into the first volume .15 . Method according to any of claims 11 to 14 further comprising heating the air or the ground level to a temperature different from a temperature in the first volume .

Images