METHODS FOR CONTROLLING PESTS

Description

[0001] The present invention relates to the technical field of pest control in crop cultivation. The present invention relates to a method for controlling pests, a system for controlling pests, and the use of a digital application map for applying one or more pest control agents.

[0002] When growing crops, there are many different organisms that can reduce yield, negatively affect the quality of the harvest, or have other undesirable effects on the crop or the harvested product.

[0003] Such pests include weeds and grasses, fungi, animal pests and pathogens.

[0004] There are also many different measures and means to prevent, reduce or combat such pests.

[0005] For example, the use of herbicides can be used to successfully control weeds and grasses in the cultivation of crops.

[0006] However, resistance to herbicides is increasingly being observed. The development of herbicide resistance is a natural process that allows plants to adapt to their environmental conditions and thus ensure their survival.

[0007] The development of resistant plants begins with individual plants that occur naturally in each population and that are resistant to the agents used.

[0008] Repeated applications of herbicides with the same or similar mechanisms of action result in selective pressure on weeds. This selective pressure favors the survival of appropriately adapted (resistant) individuals. If no strategy is implemented to prevent or interrupt this selective process, resistant individuals can become dominant within a population over time. This leads to the first control problems, and ultimately, a resistant population develops.

[0009] This applies not only to the control of weeds and grasses with herbicides but also, in an analogous manner, to the control of other pests with appropriate control agents.

[0010] In order to prevent the development of resistance, pesticides should be used only where and to the extent necessary.

[0011] Various approaches to the targeted use of pesticides have been published in recent years.

[0012] Published patent application WO95 / 01719 describes a computer system that initially divides a field into several zones, each of which is monitored independently. Irrigation and chemical application are then carried out zone by zone based on the needs determined by the monitoring. Continuous monitoring of the zones requires appropriate sensors as well as tools for data acquisition, processing, and analysis.

[0013] The US patent 6,199,000 describes a method in which an RTK GPS (Real Time Kinematic Global Positioning System) receiver is used during the planting of crops to generate a digital map of the field. Due to the high positioning accuracy of RTK GPS, the locations of individual crops are recorded on the digital map to within a few centimeters. A vehicle equipped with a suitable sensor (e.g., a "chlorophyll detector") can thus detect plants growing in places where no seed has been sown. If plants are detected in places where no seed has been sown, they are most likely weeds. These can then be controlled directly on site.

[0014] WO00 / 23937 describes a computer system. Part of the computer system is a digital map of a field, based on a photographic image and containing geographical longitude and latitude information, enabling positioning. A user can define zones in this digital map. The user can assign substance formulations (fertilizers, pesticides, herbicides) and the quantities of these substance formulations to be applied to the zones. The computer system can generate a dataset. This dataset enables a farmer, using an appropriate vehicle, to travel to the various zones of the field and apply the appropriate quantities of the formulations according to the assignments.

[0015] Carina Ritter's dissertation (Evaluation of weed populations under the influence of site-specific weed control to derive decision rules for a sustainable weed management, Institute of Phytomedicine, Weed Science Department, University of Hohenheim, under the supervision of Prof. Dr. R. Gerhards, 2008) describes how a digital distribution map of weeds (Galium aparine L. and Alopecurus myosuriodes HUDS) was created and, based on this map, herbicide was applied site-specifically using a DGPS-controlled (DGPS = Differential Global Positioning System) sprayer. Weed threshold values were sometimes taken into account. First, digital weed distribution maps were created for several years, and then herbicide treatment was carried out based on the maps, with only one herbicide formulation being applied site-specifically each year (see especially Table 1 in Chapter 2.2.2 and Table 6 in Chapter 3.2.3). It was observed that in some fields, weed nests appeared that persisted for several years.

[0016] A system for the spatially variable rate application of plant protection products consisting of a Differential Global Positioning System, a portable computer, specially developed software and a device for applying rates proportional to the machine's forward speed with the aim of minimizing the environmental impact of herbicides is proposed in M Carrara et al: 'Spatially Variable Rate Herbicide Application on Durum Weed in Sicily', Biosystems Engineering, Vol. 87, No. 4, 1 April 2004 (2004-04-1), pp. 387-392, IK, ISSN:1437-5110, DOI 10.1016 / j.biosystemseng.2004.01.004.

[0017] P. Hamouz et al.: "Impact of site-specific weed management on herbicide and savings and winter wheat yield", Plant Soil Environ., March 1, 2013 (2013-03-01), pages 101-107, concerns a study concerning the practical testing of site-specific weed management in a winter wheat field and the optimization of control thresholds. An aggregated distribution pattern of weed populations was used to reduce herbicide use when implementing site-specific weed management. For this purpose, an area spray was conducted and treatment maps were created.

[0018] Based on the described state of the art, a specialist faces the technical task of effectively and efficiently controlling pests, limiting the use of pesticides to a reasonable and economical level, and reducing the risk of developing resistance to the pesticides used. Furthermore, the development of stable nests of pests must be prevented.

[0019] This object is achieved by the subject matter of the independent claims. Preferred embodiments can be found in the dependent claims and in the following description.

[0020] A first object of the present invention is a method for controlling pests in a field where crops are grown, which is characterized by the following steps: (A) generating a digital pest distribution map, on which partial areas of the field are recorded in which the pests have been detected; (B) generating a digital application map on the basis of the digital weed distribution map, wherein the digital application map records those partial areas of the field on which one or more pesticides are to be applied, wherein for each of these partial areas a number N of treatments with one or more control agents, whereby N is greater than 1; (C) applying one or more control agents against the pests according to the digital application map from step (B), wherein the number N for the treated sub-areas is reduced by 1 as a result of the treatment; (D) repeating step (C) for each sub-area until Nhas reached the value zero, whereby control agents of different modes of action are used and the mode of action or the combination of control agents is varied from application to application.

[0021] Another (not by itself The subject matter of the present disclosure (as claimed) is a digital application map on which sub-areas of a field for crops are recorded which are to be treated with one or more pesticides, wherein for each of these sub-areas an integer N which indicates how many times the sub-area is to be treated with one or more pesticides, where N is greater than 1.

[0022] Another object of the present invention is a system for controlling pests comprising: (a) a digital application map on which those partial areas of a field are recorded which are to be treated with one or more pest control agents; (b) a positioning system; (c) an application device, comprising at least one container for holding at least one pest control agent, a spray device for applying the at least one pest control agent, and a control unit, comprising a working memory for reading the digital application map, means for communication with the positioning system and means for controlling the spray device, characterized in that on the digital application map for each partial area a number N which indicates how many times the area should be treated with the pesticide, whereby N is greater than 1, and wherein the control unit is designed such that the numberN is reduced by one after a treatment, whereby control agents of different modes of action are used and the mode of action or the combination of control agents is varied from application to application.

[0023] Another object of the present invention is the use of a digital application map on which sub-areas of a field for crops are recorded, which are to be treated with one or more control agents against pests, for the application of one or more control agents against the pests, characterized in that on the digital application map for each of the sub-areas a number N which indicates how many times the area should be treated with one or more control agents, whereby N is greater than 1, and where the number Nis reduced by one after the partial area has been treated, whereby control agents of different modes of action are used and the mode of action or the combination of control agents is varied from application to application.

[0024] The invention is explained in more detail below, without distinguishing between the subject matter of the invention (method, system, use) or the described application map. Rather, the following explanations are intended to apply analogously to all subject matter of the invention, regardless of the context (method, system, use) in which they occur.

[0025] A "pest" is defined below as an organism that can appear during the cultivation of crops and damage the crop, negatively impact the crop's harvest, or compete with the crop for natural resources. Examples of such pests include weeds, grass weeds, animal pests such as beetles, caterpillars, and worms, fungi, and pathogens (e.g., bacteria and viruses). Even though viruses are not considered organisms from a biological perspective, they are nevertheless considered to be pests for the purposes of this article.

[0026] There is sometimes overlap in the literature between the pests mentioned. In particular, in the case of fungal infestation, the terms fungus and disease are often used synonymously. A further overlap arises, for example, when an animal pest transmits a virus. In such a case, both the pest and the virus can be regarded as pests and combated with suitable control agents. However, such overlaps are irrelevant for the present invention. From the perspective of the present invention, a negative effect is observed during the cultivation of a crop in the field, which occurs in the form of nests. This effect must be eliminated with suitable control agents, whereby the amount of control agent used must be limited to a reasonable and economical level.

[0027] The term "control" refers to preventing the spread or reducing the number of pests present. In the case of weeds, for example, the term "number" refers to the biomass present in the form of weeds. However, especially in the case of a disease, the term "number" can also be understood to mean the number of crops that already exhibit symptoms of disease.

[0028] The application of a pesticide to a sub-area is also referred to herein as "treatment"; a "treated sub-area" is a sub-area to which one or more pesticides have been applied.

[0029] Pest control is achieved by applying one or more pesticides. A variety of pesticides exist for individual pests, such as herbicides (against weeds and / or grass weeds), pesticides (against animal pests), and fungicides (against fungi).

[0030] For example, weeds or grasses are controlled by applying one or more herbicides.

[0031] According to the invention, pests are controlled in a field by repeatedly applying a control agent to the locations where the pests have been detected at least once and where the formation of stable nests is to be expected.

[0032] The term "cultivated plant" refers to a plant that is purposefully cultivated as a useful or ornamental plant through human intervention.

[0033] The term "field" refers to a spatially defined area of the earth's surface that is used for agricultural purposes, in which crops are planted, supplied with nutrients and harvested.

[0034] The term "nest" refers to a part of a field where a particular pest is repeatedly observed.

[0035] The following statements primarily concern weeds and grass weeds as pests; however, they are intended to apply analogously to all possible pests. The invention is therefore not limited to weeds and grass weeds as pests, even if it is preferably used to control weeds and / or grass weeds using herbicides.

[0036] The term "weed" (plural: weeds) refers to plants of the spontaneous accompanying vegetation (segetal flora) in crop stands, grasslands, or gardens that are not deliberately cultivated there and that develop, for example, from the seed potential of the soil or via migration. The term is not limited to herbs in the true sense of the word, but also includes grasses, ferns, mosses, and woody plants.

[0037] In the field of plant protection, the term "weed" (plural: weeds) is often used to clarify the distinction from herbaceous plants. In this text, the term "weed" is used as a generic term to include weeds, unless reference is made to specific weeds or weed grasses.

[0038] Grass and weeds within the meaning of the present invention are therefore plants that accompany the cultivation of a desired crop. Since they compete with the crop for resources, they are undesirable and should therefore be controlled.

[0039] The invention is preferably used for pests known for consistently stable or recurring nests in the same parts of a field (Nordmeyer H. 2006. Patchy weed distribution and site-specific weed control in winter cereals. Precision Agric 7, 219-231). The nests are generally observed beyond one growing season of the crop. An example of a particularly preferred application is field foxtail (Alopecurus myosuroides Huds), which exhibits seed dispersal close to the parent plant (Wilson BJ, Brain P. 1991. Long-term stability of distribution of Alopecurus myosuroides Huds. within cereal fields. Weed Res 31, 367-373). In this case, the weed nests are stable or recurring; however, new ones may also appear. Other preferred examples are Orobranche crenata Forsk in broad bean (Oveisi M, Yousefi AR, Gonzalez-Andajur JL.Spatial distribution and temporal stability of crenate broomrape (Orobranche crenata Forsk) in faba bean (Vicia faba L.): A long-term study at two localities. Crop Protection 29, 2010, 717-720), Galium aparine, V. arvensis Murr., C. album L., Polygonum aviculare L. (s. Übersicht in Spatial and Temporal Dynamics of Weed Populations. In "Precision Crop Protection - the Challenge and Use of Heterogeneity. Eds.: Oerke, EC, Gerhards R, Menz G, Sikora RA. Springer, 2010, Heidelberg. ISBN 978-90-481-9276-2, S. 17-25).

[0040] Furthermore, the invention can be applied to all diseases and animal pests that exhibit spatially stable patterns. An example is infestation by nematodes (Campos-Herrera R., Johnson EG, EL-Borai FE, Stuart RJ, Graham JH, Duncan LW 2011. Long-term stability of entomopathogenic nematode spatial patterns in soil as measured by sentinel insects and real-time PCR assays, Ann Appl Biol 158: 55-68; Godefroid M., Delaville L., Marie-Luce S., Quénéhervé P. 2013. Spatial stability of a plant-feeding nematode community in relation to macro-scale soil properties. Soil Biology & Biochemistry 57: 173-181; BV Ortiz, C. Perry, P. Goovaerts, G. Vellidis, and D. Sullivane. Geoderma. 2010 May; 156(3-4): 243-252).

[0041] A "spatially stable pattern" refers to a repeatedly observable or measurable spatial distribution or arrangement of nests in a field. Furthermore, a spatially stable pattern of diseases and pests can refer to i) the cause of a disease or pest infestation, ii) the disease or pest infestation itself, and iii) a characteristic of a disease or pest infestation. For example, a pest W can transmit a virus X, which leads to a disease Y with symptom Z. It is conceivable that W, X, Y, and / or Z are measurable and each result in a stable pattern.

[0042] In particular, these patterns can be caused by an interaction between the pathogen's or pest's development cycle and other abiotic factors. The invention is therefore also applicable to regions in the field that, due to their characteristics, generally exhibit higher disease or pest pressure. Examples of such characteristics include location or exposure, hollows, soil, or field edge characteristics (e.g., hedges).

[0043] One example is Septoria leaf blight, which occurs under favorable conditions for infection by fungal spores of Septoria tritici. These favorable conditions can be caused by higher humidity or lower air exchange, due to exposure, local depressions, and / or soil type.

[0044] An example of a pest that exhibits recurring patterns is the cabbage pod midge ( Brassica oleracea) in rapeseed. Due to the low flight capacity, the distance from the winter host is crucial for infestation. A recurring pattern arises here from the location of the field relative to that of the winter host, as well as to that of the field where rapeseed was grown in the previous year.

[0045] Another example is pathogens whose infestation pressure is determined by the decomposition rate of plant residues in the soil. Stable nests can be caused by local differences in the soil.

[0046] In a first step of the method according to the invention, a digital pest distribution map is created. This map shows the areas of the field where the pests have been detected.

[0047] The term "digital" means that the card can be processed by a machine, usually a computer system. "Processing" refers to the well-known methods of electronic data processing (EDP).

[0048] Methods for generating digital maps showing locations where weeds and / or grasses have occurred are described, for example, in Carina Ritter’s dissertation: Evaluation of weed populations under the influence of site-specific weed control to derive decision rules for a sustainable weed management, Institute of Phytomedicine, Weed Science Department, University of Hohenheim, under the supervision of Prof. Dr. R. Gerhards, 2008 (see especially Chapter 1.1.5).

[0049] The methods for generating digital weed distribution maps described in GB2447681A, US 6,199,000, US 2009 / 0132132A1 and WO00 / 23937 can also be applied here.

[0050] When creating the digital pest distribution map, the field is scanned for pests. This scan can be performed by one (or more) people or purely by machine. A machine-assisted scan by one (or more) people is also conceivable. The search for pests is preferably supported by a positioning system. This means that a person or machine moves on or above the field, and the respective position of the person or machine is automatically recorded and stored using the positioning system. Suitable positioning systems are often referred to collectively as GPS (Global Positioning System).

[0051] If a human or machine discovers a pest at a location, the digital map records that a pest was found at that location.

[0052] In addition to the fact that a pest has been found at a specific location, further information can be stored on the digital map, such as the type of pest found, the quantity, the stage of development and other information.

[0053] For the mechanical detection of pests, the pest can be captured as a digital image using a photographic device and then fed into image recognition methods.

[0054] The mechanical scanning of the field for pests can be carried out, for example, using a vehicle or an unmanned aerial vehicle (drone). The use of satellite images of the field to detect pests is also conceivable.

[0055] In order to enable the area-specific use of different formulations, weeds / grasses are preferably identified in the weed distribution map as monocotyledons and dicotyledons or recorded in groups of weeds and / or grasses with regard to suitable or effective formulations.

[0056] When generating the pest distribution map, it should be noted that the pests themselves are not always necessarily observed, but rather their effects, for example, on the crop. However, this is irrelevant for the present invention. Step (A) of the method according to the invention is therefore to be understood as detecting positions in the field that indicate the presence of a pest and recording them on the digital distribution map. The pest is thus detected directly or indirectly (as a result of its effects on the environment).

[0057] The result of step (A) is a machine-readable map showing the locations where pests or their effects have been detected.

[0058] In a subsequent step, a digital application map is generated based on the digital pest distribution map.

[0059] The digital application map is machine-readable and indicates which parts of the field should be subjected to the application of one or more pesticides.

[0060] The digital application map can be a so-called ON / OFF map. For example, it is conceivable that wherever a pest is recorded on the digital pest distribution map, the corresponding application map indicates that one or more pesticides should be applied there. Wherever no pest is recorded on the pest distribution map, the digital application map indicates that no pesticide should be applied.

[0061] Such an ON / OFF card is useful, for example, if the detection method for finding pests in step (A) of the method according to the invention is not particularly sensitive, but only detects pests when they are already present in an amount where a damage threshold has already been reached or even exceeded.

[0062] If, on the other hand, the detection method is very sensitive, the application of a pesticide is preferably only entered in the digital application map when a previously defined threshold has been reached or exceeded at the corresponding location. This requires that the (approximate) quantity of the pest present (or the quantity of infested crop) is recorded on the digital pest distribution map. A planned pesticide application is then only recorded on the digital application map at those locations where the threshold of pest presence has been reached or exceeded. At all other locations, the threshold is not met; accordingly, no pesticide application is planned and no planned application is recorded on the application map.

[0063] "Damage threshold" is a term used in agriculture, forestry, and horticulture. It indicates the infestation density of pests, diseases, or weeds at which control becomes economically viable. Up to this level, the additional economic cost of control is greater than the anticipated crop loss. If the infestation or weed infestation exceeds this level, the control costs are at least offset by the expected increased yield.

[0064] Depending on the nature of a pest or disease, the damage threshold can vary greatly. For pests or diseases that are difficult to control and have negative side effects on further production, the damage threshold can be very high. However, if even a small infestation can spread to a point that threatens to destroy the entire production, the damage threshold can be very low.

[0065] There are many examples in the state of the art for determining damage thresholds (see, for example, Claus M. Brodersen: Information in damage threshold models, reports of the GIL, volume 7, pages 26 to 36, http: / / www.gil-net.de / Publikationen / 7_26.pdf).

[0066] In a preferred embodiment, information about factors that cause the occurrence of the pest or promote its spread is used to create the digital application map.

[0067] It is conceivable that the application map contains information about the quantity of the pesticide formulation to be applied. The type of pesticide or the type of formulation can also be stored on the digital application map.

[0068] The digital application map is created when a pest is first detected at a specific position and the number Nof applications for this pest at this position. The number N The frequency of applications depends on the type of pest detected. The number of applications is at least two; preferably two, three, four, or five, and is also recorded on the application map for each affected area.

[0069] In a preferred embodiment, the digital pest distribution map for a field is recreated within the period in which the multiple application of a pesticide is to be carried out according to the digital application map, and the digital application map is expanded to include newly discovered nests. Partial areas for which a pesticide application still to be carried out is recorded in the digital application map ( N>0), remain, even if no pest is currently detected. Therefore, if it has been determined for a sub-area on the digital application map that there are multiple ( N If a pesticide is to be applied to a specific area (up to 10 times), but the number of applications to be carried out has not yet been reached in reality, the information that application is to continue on this partial area remains, even if no pest has been detected at the corresponding location.

[0070] Multiple applications do not necessarily mean that the same formulation must be used multiple times. The invention proposes using sprays with different modes of action and varying the mode of action or the combination of sprays from application to application.

[0071] The formulation can also be adjusted accordingly in subsequent years if another pest is detected in the same area of a field. In particular, this can result in parts of a field with one pest each being treated with one formulation, while shared areas with multiple pests are treated with a different formulation.

[0072] This is explained using the following examples, in which two weeds (Weed 1 and Weed 2) occur on the same part of a field. Example 1: Weed 1 and weed 2 are sensitive to herbicide 1 → Herbicide 1 is applied. Example 2: Weed 1 is sensitive to herbicide 1 and weed 2 is sensitive to herbicide 2 and no usable herbicide is known that is effective against both weed 1 and weed 2 → Herbicide 1 and herbicide 2 are applied. Example 3: Weed 1 is sensitive to herbicide 1 and weed 2 is sensitive to herbicide 2 and a usable herbicide 3 is known that is effective against both weed 1 and weed 2 → Either herbicide 3 alone or herbicide 1 in combination with herbicide 2 can be applied.

[0073] For example, the following control agents are used to control the weed blackgrass: in autumn application from BBCH stage 11, a sulfonyl mixture consisting of the active ingredients mesosulfuron and iodusulforone (preferably plus a safener) is used. When alternating active ingredients, propoxycarbazone or pyroxsulam and florasulam are used. If the weed repeatedly exceeds the damage threshold in spring, then a spring treatment with, for example, the active ingredients mesosulfuron and iodusulforone (plus a safener) is also carried out. In addition to the group of ALS inhibitors, there is also another group of active ingredients: the ACCase inhibitors with the so-called FOPS. The type of active ingredient and the application rate depend on the type of weed or grass, the number of plants per m² or biomass of the weed or grass, and the degree of resistance.

[0074] It is also conceivable that the digital application map contains commands for an application device for a pesticide formulation. This means that the digital application map, or parts thereof, can be loaded into the working memory of an application device, from where the commands are transmitted to a spraying device.

[0075] An application device is understood to be a mechanical device for applying a pesticide formulation to a field. Such an application device generally comprises at least one container for holding at least one pesticide formulation, a spray device for dispensing the pesticide formulation onto the field, and a control device for controlling the conveyance of the at least one pesticide formulation from its container toward the spray device. Accordingly, the digital application map is preferably stored in the working memory of the control unit. Furthermore, the control unit is preferably connected to a positioning system that determines the position of the application device in the field.Preferably, the control device starts the application process when the digital application map indicates that an application is to be carried out at a location and when the positioning system reports that the application device is currently located at this location.

[0076] In a next step of the method according to the invention, one or more control agents against the pests identified in step (A) are applied using the digital application map.

[0077] In one embodiment, a person (user) uploads the digital application map to a mobile computer system, e.g. a mobile phone (smartphone) that has a GPS receiver. As the user walks across the field, the mobile computer system uses a graphic image of the field to show them where they are and where they should manually spray (apply) one or more pesticides. The user then sprays manually at the locations where the application map contains a corresponding instruction. If the user applies a pesticide to a location, it is conceivable that appropriate sensors will send the mobile computer system feedback on the application process that has been completed, and that the application process will be saved.It is also conceivable that the completed application process is displayed on the mobile computer system so that the user can see where the application has already been made. Furthermore, it is conceivable that the data recorded on the mobile computer system is transmitted immediately or at a later time to a stationary computer system (e.g., a server) and stored there. In any case, the completed application is recorded for each sub-area in the digital application map in such a way that the number . N the number of applications (treatments) still to be carried out is reduced by one.

[0078] It is also conceivable for a person to drive a vehicle across the field, for the respective position of the vehicle to be recorded by means of a GPS receiver, and for commands to be transmitted to a spraying device on the vehicle based on the digital application map when the vehicle is at a location in the field where, according to the application map, one or more pesticides are to be applied, whereupon the corresponding application is carried out automatically.

[0079] It is also conceivable that the application of one or more control agents is fully automated: an unmanned machine moves across the field using GPS and applies the product to the locations where the digital application map indicates a corresponding application. The completed application is again recorded in the digital application map: the number of treated areas is recorded. N reduced by one.

[0080] The control of pests with appropriate chemical and / or biological plant protection products can be supplemented by physical / mechanical control methods.

[0081] Physical (or mechanical) removal refers to the complete removal of weeds or grasses as pests, or the removal of parts of them so that they are no longer viable and die. Unlike controlling weeds or grasses with a herbicide, which can be considered chemical control, physical / mechanical control does not involve the application of any chemical or biological agent. Physical / mechanical control therefore does not exert any selective pressure on the weeds or grasses, but is often more complex and expensive than applying herbicides.

[0082] Physical / mechanical control also includes, for example, irrigation, which is used to encourage weeds to emerge in order to then eliminate them. Physical / mechanical control also includes flame-fighting the pests.

[0083] For example, it is conceivable to use chemical and physical processes alternately.

[0084] It is also conceivable that part of an area is treated chemically and another part physically.

[0085] However, a combined approach in a single operation is also conceivable, for example, if the use of chemicals is limited due to legal regulations or if a combination of pests is present where combined control with mechanical and chemical means offers the best chance of success. The combined application of physical and chemical methods can also be useful if the combination produces a synergistic effect.

[0086] In a preferred embodiment, the pest is physically removed at those locations in the field where no threshold value of a pest has been exceeded but where a pest has been detected.

[0087] Applying one or more pesticides based on the digital application map will take a certain amount of time. This time depends, for example, on the size of the field, the number of locations in the field where application is to take place, the size of these locations, and the amount of pesticide that an application device can carry (in some cases, the amount of pesticide that an application device can carry is not sufficient to supply all locations listed on the application map, so the application device must be refilled one or more times, which takes time).

[0088] "Processing the application map" is the process in which all locations in the field for which one or more pesticides are to be applied are recorded on the digital application map, have been visited by an application device and the corresponding application has been carried out.

[0089] If the application map is processed for the first time after it has been created, this process is referred to here as "first application".

[0090] Depending on the size of the field, processing the digital application map will usually take less than one day to two weeks.

[0091] The duration of the first processing therefore takes place within a first time period.

[0092] A key feature of the invention is that the digital application map is processed at least a second time. The nests identified on the application map are then sprayed with a control agent multiple times (e.g., twice, three times, four times, or five times).

[0093] Thus, after step (C) of the method according to the invention, a step (D) takes place in which the same locations on the application map are sprayed again within a second period of time (second processing of the application map).

[0094] It is conceivable that the same application map is processed a third time within a third time period.

[0095] It is conceivable that the same application map is processed a fourth time within a fourth time period.

[0096] A further repeated processing is conceivable, but each subsequent processing after the third is less likely.

[0097] Steps (C) and (D) can therefore also be summarized under the point: multiple application of the digital application map generated in step (B) in such a way that for the parts of the field where a damage threshold of one or more pests is exceeded, multiple ( N -fold) one or more control agents are applied (even if no pest is detected at the time of application).

[0098] As described above, the application map can be expanded at any time by including newly detected nests.

[0099] Between the first processing of the application map within the first time period (step (C)) and the second processing of the application map within the second time period (step (D)), there is a period in which no application of a pesticide takes place. This period is at least one day, preferably at least one week, and even more preferably at least one month. If the application map is processed a third time in a third time period, there is again a period of at least one day, preferably at least one week, and even more preferably at least one month, between the second time period and the third time period in which no application takes place.

[0100] The same applies to each further processing of the application map.

[0101] The time interval between two treatments of a sub-area is largely determined by when a recurrence of pests is expected. Therefore, a sub-area should preferably only be treated again when a recurrence of pests is expected, especially before a renewed infestation of the sub-area spreads to other sub-areas.

[0102] The multiple (at least two) applications of the application clearing are preferably carried out over the current vegetation year and / or subsequent vegetation years, in each case within the period of the pre-emergence phase until the end of the vegetation period of the crop grown in the field.

[0103] The "pre-emergence phase" refers to the period from the first day after harvest of the previous crop to the last day before emergence of the crop.

[0104] In one embodiment of the present invention, the period between two applications corresponds to the duration of a vegetation period of the cultivated crop (plus / minus 1 day to 8 weeks).

[0105] Preferably, an extended digital pest distribution map is created on the agricultural field every year, firstly to check the pest population and secondly to adapt the digital application map by, where appropriate, recording newly added locations where a pest threshold has been exceeded.

[0106] The invention leads to a reduced development of resistance, particularly in the effective control of weeds / grasses, for example: The resistance pressure in a field with site-specific application is overall lower than in a field without site-specific application, because only a portion of the field is exposed to selection pressure. By applying the same amount or concentration of a herbicide to a site as with non-site-specific application, so-called multigene resistances, which otherwise build up quantitatively with repeated spraying with low doses, are avoided. This corresponds to 'good agricultural practice'. Repeated application of the application map makes the survival of individual weeds / grass weeds less likely on the identified patches of the weed identification map. Annual compilation of the map verifies this fact and thus counteracts resistance in untreated areas.The use of different herbicides increases treatment success and thus reduces the development of resistance to a particular herbicide.

[0107] The invention is explained in more detail below using an example.

[0108] Fig. 1 shows different representations of a field at different times t 1 until t 6 . The field representations are shown as rectangles. The top row, labeled U1, is a weed distribution map for weed U1. The middle row, labeled U2, is a weed distribution map for weed U2. The bottom row, labeled A, is an application map for two different herbicides, H1 and H2.

[0109] Time is divided into six snapshots t 1 until t 6 Time progresses column by column from left to right.

[0110] The first column therefore shows the field at a first point in time, the second column at a later point in time, and so on. The time spans between two columns can, for example, be the duration of a growing season (usually one year) of the crop being grown in the field. They can also be the growing season of a weed / grass weed. Typically, one or more herbicides were applied in the period between two consecutive columns – this is shown in the bottom row A – unless no weeds were detected over several time periods (last column).

[0111] The top line shows where in the field at the time t 1 until t 6 the weed U1 has been detected.

[0112] The fields U1( t 1 ) , U1( t 2 ) , U1( t 3 ), U1( t 4 ), U1( t 5 ) and U1( t 6 ) thus represent weed distribution maps with respect to weed U1. Analogously, the fields U2( t 1 ) , U2( t 2 ) , U2( t 3 ) , U2( t 4 ), U2( t 5 ) and U2( t 6 ) Weed distribution maps related to weed U2. The distributions of weeds 1 and 2 could have been combined into a single distribution map, but they are shown separately here.

[0113] At the time t 1 a weed U1 was identified in the field; the weed U1 was present in the form of a circular area (= partial area) (see U1( t 1 )) .

[0114] At the same time t 1 there was no weed U2 in the field (see U2( t 1 )).

[0115] From the weed distribution maps U1( t 1 ) and U2( t 1 ) an application map A( t 1 ) is created. Since only the weed U1 has been detected in the field, the application map contains A( t 1 ) also only information and instructions regarding the weed U1. In the application map A( t 1 ) a circular area is marked with a hatching, where in U1( t 1 ) the weed U1 has been detected. The herbicide H1 is to be applied in this area. The number 3 above the hatched area indicates that this area is to be treated with the herbicide H1 a total of three times (N=3).

[0116] At a later time after the application of the herbicide H1, in U1( t 2 ) that weed U1 is apparently no longer present in the previous circular area; the application of herbicide H1 was obviously successful. Instead, however, a crescent-shaped area has formed next to the previous circular area in which weed U1 was detected. Weed U1 has therefore shifted to the right in the field.

[0117] In addition, a weed U2 has appeared (see U2( t 2 )) . From these findings, the application map A( t 2 ). First of all, in A( t 2 ) shows that the herbicide H1 should continue to be applied in the circular area where in U1( t 1 ) the weed U1 has been detected, even if it is in U1( t 2 ) has no longer been detected. This is precisely the core of the present invention: the application map A( t 1 ) is applied / processed multiple times. The number 2 above the hatched area indicates that this sub-area will be applied twice more ( N =3-1=2) should be treated with the herbicide H1.

[0118] The application map A( t 1 ) is based on the findings in U1( t 2 ) and U2( t 2 ) to A( t 2 ) has been expanded. Since a crescent-shaped area of weeds U1 in U1( t 2 ) was detected, the hatched area in A( t 2 ) accordingly. The number 3 above the extended hatched area indicates that this extended area has been extended three times ( N =3) should be treated with the herbicide H1.

[0119] Additionally, in A( t 2 ) indicates that herbicide H2 should be applied in the area (wavy area) where in U2( t 2 ) Weed U2 has been detected. The number 4 below the wavy area indicates that this area has been detected four times ( N =4) should be treated with the herbicide H2.

[0120] In U1( t 3 ) shows that the weed area U1 has shifted further to the right. In U2( t 3 ) the weed U2 has completely disappeared. A( t 3 ) represents the U1( t 3 ) and U2( t 3 ) corresponding application map. In the circular area of A( t 1 ) should also be according to A( t 3 ) herbicide H1 was applied once more ( N =1). Also in the crescent-shaped area shown in A( t 2 ) has been added to the circular area, herbicide H1 should continue to be applied, twice more ( N =2). In addition, herbicide H1 should be applied in the area that is in U1( t 3 ) has recurred, namely three times in total ( N =3).

[0121] According to A( t 3 ) Herbicide H2 should also be applied once more, in the same area as in A( t 2 ). There are in U2( t 3 ) no new areas with weed U2 were added.

[0122] In U1( t 4 ) shows that after the application according to A( t 3 ) no more weeds U1 have been detected in the field. In U2( t 4 ) shows that after the application according to A( t 3 ) no more weeds U2 have been detected in the field. Nevertheless, according to A( t 4 ) the herbicides H1 and H2 were applied. In the circular area from A( t 1 ) is converted into A( t 4 ) for the first time no herbicide H1 was applied ( N =0). Herbicide H1 was applied three times in this area – this number of applications is sufficient to permanently eliminate the nest.

[0123] In the crescent-shaped areas shown in A( t 2 ) and A( t 3 ) have been added to the circular area, it should be applied again; in the case of the crescent-shaped area that appeared first (see U1( t 2 )) once again ( N =1), in the case of the crescent-shaped area that appeared afterwards (see U1( t 3 )) twice more ( N =2).

[0124] The area from U2( t 2 ) is converted into A( t 4 ) should be twice more ( N =2) be treated with herbicide H2.

[0125] In U1( t 5 ) and U2( t 5 ) no weeds have been detected. However, it should continue to be used according to A( t 5 ) Herbicide H1 and Herbicide H2 are applied: one last time ( N =1) in the range of U1( t 3 ) with herbicide H1 and a final ( N =1) times in the range of U2( t 2 ) with herbicide H2.

[0126] U1( t 6 ) and U2( t 3 ) indicate that no more weeds have been detected. According to A( t 6 ) no application of a herbicide is necessary.

[0127] It should be noted that this example does not explicitly address the damage thresholds for weeds U1 and U2. In this example, it could be assumed, for example, that whenever weeds U1 or U2 were detected in the field, the damage thresholds were exceeded.

Claims

1. A method for controlling harmful organisms on a field on which cultivated plants are cultivated, which method has the following steps: (A) generating a digital harmful-organisms distribution map, registered on which are subareas on the field in which the harmful organisms have been detected directly or indirectly; (B) generating a digital application map on the basis of the digital harmful-organisms distribution map, it being registered on the digital application map those subareas of the field on which one or more control agents against the harmful organisms are to be applied, it being registered for each of said subareas a number N of treatments with one or more control agents, where N is greater than 1; (C) applying one or more control agents against the harmful organisms as per the digital application map from step (B), the number N for the treated subareas being reduced by 1; (D) repeating step (C) for each subarea until N has reached the value zero, control agents of different modes of action being used and the mode of action and / or the combination of control agents being varied from application to application.

2. The method according to claim 1, wherein those subareas of the field in which harmful organisms have been detected directly or indirectly in step (A) and in which an economic threshold has been reached or exceeded are incorporated into the digital application map.

3. The method according to claim 1, wherein those subareas of the field in which nests of harmful organisms have been detected in step (A), which nests have survived after an application of one or more control agents, are incorporated into the digital application map in step (B).

4. The method according to claim any of claims 1 to 3, wherein the harmful organisms are broad-leaved weeds and / or grass weeds and the one or more control agents are one or more herbicides.

5. The method according to claim any of claims 1 to 3, wherein the harmful organisms are animal pests, preferably nematodes or brassica pod midges, and the one or more control agents are pesticides against animal pests.

6. The method according to any of claims 1 to 5, wherein the number N in the generation of the digital application map is set to two, three or four.

7. The method according to any of claims 1 to 6, wherein a digital harmful-organisms distribution map is generated again as per step (A) after an effected application of one or more control agents to the subareas concerned, and additions are made in step (B) in the existing digital application map of those regions in which harmful organisms have been detected in the new digital harmful-organisms distribution map, the subareas in which N has not yet reached the value zero remaining in force and subareas in which N has reached the value zero being deleted.

8. The method according to any of claims 1 to 7, wherein the control of the harmful organisms with a control agent is accompanied by a physical control or wherein a physical control of the harmful organisms takes place at least in part of the regions of the field in which harmful organisms have been detected, but in which no economic threshold has been exceeded.

9. The use of a digital application map for the application of one or more control agents against harmful organisms, it being registered on the digital application map subareas of a field for cultivated plants that are to be treated with one or more control agents against harmful organisms, it being registered for each of said subareas an integer N which specifies how many times the subarea is to be treated with one or more control agents for the harmful organisms, where N is greater than 1, wherein the subareas to be treated are treated N times with one or more control agents, the number N being reduced by 1 after an effected treatment of the subarea, and control agents of different modes of action being used and the mode of action and / or the combination of control agents being varied from application to application.

10. The use of a digital application map according to claim 9, wherein it is registered on the application map those subareas in which a harmful organism has reached or exceeded an economic threshold.

11. The use of a digital application map according to either of claims 9 and 10, wherein the harmful organisms are broad-leaved weeds and / or grass weeds and the one or more control agents are one or more herbicides.

12. The use of a digital application map according to either of claims 9 and 10, wherein the harmful organisms are animal pests, preferably nematodes or brassica pod midges, and the one or more control agents are pesticides against animal pests.

13. The use of a digital application map according to either of claims 9 and 10, wherein the harmful organisms are fungi, preferably Septoria, and the one or more control agents are fungicides.

14. The use of a digital application map according to any of claims 9 to 13, in which subareas to be treated N times with one or more control agents have been incorporated at a point in time at which at least one of the subareas already existing in the digital application map has been treated at least once with one or more control agents.

15. A system for controlling harmful organisms, comprising: (a) a digital application map, registered on which are those subareas of a field which are to be treated with one or more control agents for the harmful organisms; (b) a position determination system; (c) an application device comprising - at least one container for accommodating at least one control agent against the harmful organisms, - a spray device for applying the at least one control agent, and - a control unit comprising a working memory for reading in the digital application map, means for communicating with the position determination system and means for controlling the spray device, wherein a number N is registered on the digital application map for each of the subareas, which number specifies how many times a treatment of the subarea with the control agent is to take place, N being greater than 1, and the control unit being equipped in such a way that the number N is reduced by one after a treatment has taken place, and wherein the control unit starts the application of at least one control agent by means of the spray device when the position determination system signals that the application device is situated at a site at which the application of the at least one control agent is envisaged according to the digital application map, control agents of different modes of action being used and the mode of action and / or the combination of control agents being varied from application to application.

16. The system according to claim 15, wherein the harmful organisms are broad-leaved weeds and / or grass weeds and the one or more control agents are one or more herbicides.