Plant disease and pest control device

Abstract

To provide a control device for plant pests, that can surely control plant pests without using agricultural chemicals.SOLUTION: A control device includes: electrode plates 3, 3 that are arranged by oppositely facing each other on both sides of a plant 2; and an electric power unit 4 that applies a voltage to the electrode plates 3, 3. By applying a pulse electric field between the electrode plates 3, 3, pests are controlled which are parasitic on the plant 2 interposing between the electrode plates 3, 3. The applying method of the pulse electric field is such that an application for a constant time with the pulse electric field having a prescribed pulse repetition frequency is defined as one application, and this is repeated for several times a day.SELECTED DRAWING: Figure 1

Description

Technical Field

[0001] The present invention relates to a plant pest control device using a pulsed electric field.

Background Art

[0002] In the cultivation of plants such as agricultural crops and flowers, many pesticides are used for the purpose of preventing the occurrence of pests and diseases. However, the use of such pesticides causes various environmental problems, such as the impact on the ecosystem, the scattering to the neighborhood, and the impact on the water system due to underground runoff, and there are concerns about the impact on the human body by inhaling the components contained in the pesticides. In addition, due to the problem of residual pesticides on crops, the use concentration, application time, and frequency are restricted.

[0003] In addition, with respect to the use of pesticides, there is a problem that pests and pathogens acquire resistance and the effect thereof decreases, and it has not been possible to completely suppress the occurrence of pests and diseases only by spraying pesticides. For example, the two-spotted spider mite is an important agricultural pest that damages many agricultural crops, but the development of drug resistance is remarkable and the effects of many pesticides are reduced.

[0004] In recent years, due to the reduction of the impact on the ecosystem and the ensuring of food safety, low-pesticide and pesticide-free cultivation methods have attracted increased attention.

[0005] As a technique for preventing the occurrence of pests and diseases without using pesticides, Patent Document 1 below discloses a flying organism removing device that applies an electrostatic field to flying organisms such as spores or cells of plant pathogens or small pests that cause plant pests and diseases, in order to kill them by discharging electricity and prevent the occurrence of plant pests and diseases.

Prior Art Documents

Patent Documents

[0006]

Patent Document 1

Summary of the Invention

Problems to be Solved by the Invention

[0007] The flying organism removing device disclosed in Patent Document 1 is installed in an opening for air supply and exhaust formed in a wall surface of an agricultural house or the like, and a DC voltage is applied to two conductors arranged at a certain distance inside the device, thereby causing a discharge in flying organisms passing between them to remove the flying organisms by the discharge. As a result, although the invasion of pests from the opening where the flying organism removing device is installed can be prevented, pests that invaded from other places and parasitized on plants inside the house had to be removed using pesticides. In addition, this device could not be used for open field cultivation.

[0008] Therefore, the main problem of the present invention is to provide a plant pest control device that can surely control plant pests without using pesticides.

Means for Solving the Problems

[0009] As the present invention according to claim 1 for solving the above problems, In elevated cultivation where a pedestal is provided and a cultivation tank is installed at a position higher than the ground, and plants are planted in the cultivation tank, electrode plate mounting frames erected on the ground are arranged on both sides of the plants in the cultivation tank, electrode plates are respectively mounted on the electrode plate mounting frames on both sides, and a control device is provided with a power supply device for applying a voltage to the electrode plates, By applying a pulsed electric field between the electrode plates, pests parasitizing on plants intervening between the electrode plates are controlled in this case, a rail along which the electrode plate can travel is provided along the plant rows on the electrode plate mounting frame, and by moving the electrode plate along this rail, a pulsed electric field can be applied to all plants. There is provided a plant pest control device characterized by this.

[0010] In the invention described in claim 1 above, In elevated cultivation, Electrode plates are arranged facing each other on both sides of a plant, and by applying a pulsed electric field between these electrode plates, pests parasitizing on plants intervening between the electrode plates are controlled in this case, a rail along which the electrode plate can travel is provided along the plant rows on the electrode plate mounting frame that supports the electrode plate, and by moving the electrode plate along this rail, a pulsed electric field can be applied to all plants. is being carried out. The pulsed electric field is a pulsed electric field generated by discharging electrical energy in an extremely short time. By applying this pulsed electric field to pests, the pests parasitizing on plants can be surely controlled without using pesticides due to the action inhibition effect and sterilization effect of the pests.

[0011] As the invention according to claim 2, there is provided a plant pest control device according to claim 1, wherein the pulse electric field having a predetermined pulse repetition frequency is applied for a certain period of time once, and this is repeated several times a day.

[0012] In the invention described in claim 2 above, the method of applying the pulse electric field in a day is defined. Specifically, applying the pulse electric field having a predetermined pulse repetition frequency for a certain period of time once, and repeating this several times a day. Thereby, plant pests can be controlled more reliably.

[0013] As the invention according to claim 3, there is provided a plant pest control device according to the claim, wherein, each time, after applying the pulse electric field for several minutes, the application of the pulse electric field is repeated several times with an interval. 1 described.

[0014] In the invention described in claim 3 above, among the methods of applying the pulse electric field per time, a more preferable form is defined. As a result of experiments, the application method of repeatedly applying the pulse electric field for several minutes with an interval was the most effective in suppressing the behavior of pests.

[0015] As the invention according to claim 4, a photographing device for photographing plants is provided, and an analysis means is provided for analyzing the color and state of leaves and flowers in the image photographed by this photographing device, and for changing any one or two or more of the application time, electric field strength, and number of applications of the pulsed electric field according to the identification result. The plant pest control device according to claim 1 is provided.

[0016] In the above claim 4 described invention, By providing an analysis device that analyzes the image photographed by the photographing device to identify the color and state of leaves and flowers, and changes any one or two or more of the application time, electric field strength, and number of applications of the pulsed electric field according to the identification result, it becomes possible to effectively apply a pulsed electric field to plants.

[0017] As the claim 5 relating to the invention, there is provided a plant pest control device according to any one of claims 1 to 4 wherein the outside of the electrode plate is covered with an electrically insulating member.

[0018] In the above claim 5 described invention, by covering the outside of the electrode plate with a member made of an electrically insulating sheet material, a plate material, etc., it is possible to prevent a person from accidentally contacting the electrode plate and ensure safety.

Effects of the Invention

[0019] As described in detail above, according to the present invention, it becomes possible to surely control plant pests without using pesticides.

Brief Description of the Drawings

[0020]

Figure 1

Figure 2

Figure 3

Figure 4

Embodiments for Carrying Out the Invention

[0021] Hereinafter, embodiments of the present invention will be described in detail with reference to the drawings.

[0022] As shown in FIG. 1, the plant pest control device 1 according to the present invention includes electrode plates 3, 3 disposed opposite to each other on both sides of a plant 2, and a power supply device 4 that applies a voltage to the electrode plates 3, 3.

[0023] As a cultivation method of the plant 2 to which the present control device 1 can be applied, as shown in FIGS. 1 and 2, it may be elevated cultivation in which a gantry 5 is provided and a cultivation tank 6 is installed at a position higher than the ground, and the plant 2 is planted in this cultivation tank, or as shown in FIG. 3, ridge cultivation may be performed on the ground, etc., and the plant 2 may be directly planted in this ridge.

[0024] In the control device 1 shown in FIG. 1, electrode plate mounting frames 7, 7 standing on the ground are arranged on both sides of the plant 2, and electrode plates 3 are respectively attached to the electrode plate mounting frames 7, 7 on both sides. In the illustrated example, a connecting member 8 for connecting the electrode plate mounting frames 7, 7 on both sides is appropriately provided. Thus, in the case of the control device 1 with the electrode plate 3 attached to the electrode plate mounting frame 7, it is preferably used in a cultivation form indoors such as greenhouse cultivation in order to avoid the electrode plate 3 being exposed to rainwater and short-circuiting during rainfall. However, it is also possible to use it outdoors after taking measures to avoid electrical short-circuiting of the electrode plate 3 due to liquids such as rainwater. On the other hand, as will be described later, when the electrode plates 3, 3 are attached to the mobile control device 1A (see FIG. 3), it is only necessary to move the mobile control device 1A to a place where it is not hit by rain during rainfall. Therefore, it is applicable not only to greenhouse cultivation but also to open-field cultivation.

[0025] And in the plant disease and pest control device 1 according to the present invention, by applying a pulsed electric field between the electrode plates 3, 3, the disease and pests parasitizing on the plant 2 intervening between the electrode plates 3, 3 are controlled. As described in the experimental results in the following section, by applying a pulsed electric field to pests (thrips), an action inhibitory effect on the pests can be confirmed, and it has also been reported that the pulsed power has a bactericidal effect. Therefore, diseases caused by the growth of fungi such as powdery mildew can also be prevented. For this reason, plant diseases and pests can be surely controlled without using pesticides.

[0026] The pulsed electric field is a pulsed electric field generated by releasing electrical energy in an extremely short time (pulse width). The pulse width is preferably several hundred nanoseconds or more, preferably in the order of several hundred nanoseconds to microseconds. The upper limit of the pulse width is considered in view of applying stress to the pests by narrowing the target without causing significant damage to the plants in the environment where the plants and pests coexist. This pulsed electric field is repeatedly applied at a constant period, and the pulse repetition frequency at that time is preferably 100 to 10,000 pps, more preferably 500 to 5,000 pps, and even more preferably 800 to 1,200 pps.

[0027] In addition, the electric field strength of the pulsed electric field preferably falls within a range that does not adversely affect plant growth while being strong enough to affect the target pests and diseases.

[0028] The application time of the pulsed electric field (the apparent time including the non-application time between pulses when applied at a predetermined pulse width and a predetermined pulse repetition frequency) is 1 to 30 minutes, preferably 5 to 30 minutes, more preferably 12 to 25 minutes.

[0029] As the method of applying the pulsed electric field, it is preferable to define one application of a pulsed electric field having a predetermined pulse repetition frequency for a certain period of time as one time, and repeat this several times a day, specifically 2 to 6 times. By applying it several times a day, the control of pests and diseases can be more reliable.

[0030] As the application method per time, it may be applied continuously during a predetermined application time. However, from the experimental results described later, it is preferable to adopt an application method in which the pulsed electric field is applied for several minutes, then an interval is left, and the pulsed electric field is applied again for several minutes and repeated several times. The application time of the pulsed electric field between each interval is preferably about 2 to 6 minutes, and this is preferably repeated about 2 to 6 times with an interval, and the total application time is preferably about 10 to 30 minutes. Also, the interval time is preferably about 3 to 10 minutes.

[0031] The electrode plate 3 is a plate made of a conductive metal or the like, and is arranged on both sides of the plant 2 in a state of being separated from the plant 2 so that their planes face each other. Of the opposing electrodes 3, 3, one electrode 3 is connected to the positive electrode of the power supply device 4, and the other electrode 3 is connected to the negative electrode of the power supply device 4.

[0032] As shown in FIG. 1, the outer surface of the electrode plate 3 (the surface on the side opposite to the surface where the electrode plates 3 face each other and the side opposite to the plant 2) is preferably covered with an electrically insulating member 9. Thereby, an accident in which a person accidentally touches the electrode plate 3 and gets an electric shock can be prevented, and the safety can be enhanced. The electrically insulating member 9 is made of a known electrically insulating material such as rubber, resin, porcelain, glass, or wood, and is processed into a sheet shape or a plate shape.

[0033] FIG. 2 is an example of an embodiment in the case where a large number of plants 2, 2... are planted in a row. In this case, a large number of the electrode plates 3 may be arranged in series along the row in which the plants 2 are planted. However, as shown in the illustrated example, it is preferable to movably provide one electrode plate 3, 3 arranged on each side of the plant 2 along the row in which the plant 2 is planted. Thereby, a pulsed electric field can be applied to the entire plant 2 planted over a wide range with a minimum number of electrode plates 3.

[0034] In order to movably provide the electrode plate 3 along the row in which the plant 2 is planted, as shown in FIG. 2, in an embodiment in which the plant 2 is cultivated at a high position and the electrode plate 3 is attached to the electrode plate mounting frames 7 arranged on both sides thereof, a rail 10 on which the electrode plate 3 can travel is provided along the row of the plant 2 on the electrode plate mounting frame 7, and the electrode plate 3 moves along this rail 10, so that a pulsed electric field can be applied to all the plants 2.

[0035] As another exemplary form of movably providing the electrode plate 3 along the row in which the plants 2 are planted, as shown in FIG. 3, in soil cultivation where a large number of plants 2 are directly planted on the ground along the ridges, it comprises a vehicle body 11 and a traveling body 12 that supports the vehicle body 11 so as to be able to travel. The vehicle body 11 is formed in an arch shape that straddles the ridges, and the traveling body 12 travels on the passages on both sides of the ridges. A movable control device 1A provided with the electrode plates 3 may be provided on both sides of the arch legs of the vehicle body 11. This movable control device 1A may be a self-propelled type equipped with an engine or a motor, or may be configured to be movable by being connected to another vehicle, or may be movable manually. By making the control device itself provided with the electrode plate 3 movable, it becomes unnecessary to provide the electrode plate mounting frames 7 on both sides of the plant 2, and the application range of the control device can be expanded. Incidentally, the movable control device 1A may be applied to high-set cultivation by raising the legs of the vehicle body 11.

[0036] As another exemplary form, a photographing device for photographing the plant 2 is provided, and an analysis means is provided to analyze the image photographed by this photographing device to identify the color and state of leaves and flowers, etc., and change any one or two or more items of the application time, electric field strength, and application frequency of the pulsed electric field according to the identification result. For example, in the case of leaf sap-sucking damage by thrips, a large number of spots are observed on the leaves, and the analysis means can take measures such as increasing the application frequency of the pulsed electric field for the plant 2 that has developed these spots.

Example

[0037] An experiment was conducted to observe the behavior of thrips, which are major pests in agriculture, when a pulsed electric field was applied to them.

[0038] The experimental method is as follows. (1) A transparent container made of glass or acrylic containing the pests 20 (thrips) is placed between the electrode plates 3, 3. (2) Apply a pulsed electric field with a predetermined electric field strength, pulse repetition frequency, and application time. (3) Observe the reaction of the pests 20 during the application. Observe the reaction of the pest 20 after stopping.

[0039] The experimental conditions and results are as shown in Table 1.

Table 1

Description of Signs

[0040] 1... Control device for plant pests, 2... Plant, 3... Electrode plate, 4... Power supply device, 5... Stand, 6... Cultivation tank, 7... Electrode plate mounting frame, 9... Electric insulating member, 10... Rail, 11... Vehicle body, 12... Running body

Claims

1. In elevated cultivation where a cultivation tank is installed at a position higher than the ground by providing a stand, and plants are planted in the cultivation tank, electrode plate mounting frames erected on the ground are arranged on both sides of the plants in the cultivation tank, electrode plates are respectively attached to the electrode plate mounting frames on both sides, and a control device is provided with a power supply device for applying a voltage to the electrode plates, when controlling pests parasitic on the plants intervening between the electrode plates by applying a pulsed electric field between the electrode plates, rails along which the electrode plates can travel are provided along the plant rows on the electrode plate mounting frames, and the pulsed electric field can be applied to all plants by moving the electrode plates along these rails. A plant pest control device characterized by this.

2. The plant pest control device according to Claim 1, wherein the application of the pulsed electric field having a predetermined pulse repetition frequency for a certain period of time is regarded as one time, and this is repeated several times a day.

3. The plant pest control device according to Claim 1, wherein after applying the pulsed electric field for several minutes each time, the application of the pulsed electric field is repeated several times with an interval.

4. The plant pest control device according to Claim 1, further comprising a photographing device for photographing plants, analyzing the image photographed by this photographing device to identify the color and state of leaves and flowers, and having an analysis means for changing any one or two or more items of the application time, electric field strength, and application frequency of the pulsed electric field according to the identification result.

5. The plant pest control device according to any one of Claims 1 to 4, wherein the outside of the electrode plate is covered with an electrically insulating member.

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