JP6194212B2 - How to kill insects - Google Patents

Description

  The present invention relates to a method for killing pests, and more particularly to a method for killing pests that uses carbon dioxide to kill pests attached to plants and the like.

  An insecticidal technique using carbon dioxide is known as a technique for killing pests attached to harvested crops and the like.

  The insecticidal technique proposed in Patent Document 1 is one of insecticidal techniques for killing pests attached to harvested crops using high-pressure carbon dioxide. This insecticidal technique kills pests attached to crops by the following process. First, an insecticidal object is placed in a pressure resistant chamber. Next, a depressurization treatment step is performed in which the pressure in the chamber is reduced to −0.1013 MPa to −0.05 MPa. Next, a pressure holding process is performed in which carbon dioxide is sealed so as to have a pressure of 0.6 MPa to 1.5 MPa, and the pressure is maintained for 15 to 90 minutes. Next, a return pressure treatment step for releasing carbon dioxide and returning to normal pressure is performed. After that, insects are killed by repeating the decompression process, the pressure holding process, and the decompression process one or more times.

  This insecticidal technique is effective in killing pests attached to fruit trees such as rice, wheat and other grains, soybeans, red beans and other beans, chestnuts, and cassava, sweet potatoes and other potatoes.

JP 2008-266302 A

  The insecticidal technique of Patent Document 1 is an insecticidal technique in which carbon dioxide is introduced into a chamber and pressurized and sealed so as to have a pressure of 0.6 MPa to 1.5 MPa. Since this technique includes a pressurizing step, it is an effective insecticidal technique when pests attached to relatively hard crops such as cereals, beans, chestnuts and potatoes are killed.

  However, when a pest attached to a growing plant such as a seedling is killed by the insecticidal technique of Patent Document 1, the pressurizing step damages the plant. Similarly, leaf insects are also damaged when insects of relatively soft leafy vegetables such as cabbage and lettuce are killed by the insecticidal technique of Patent Document 1.

  The present invention has been made to solve the above-mentioned problems, and its purpose is not only to relatively hard crops but also to pests on the surface of growing plants and relatively soft crops, and to sink inside. An object of the present invention is to provide a method for killing pests that can kill the pests that are present.

  In order to solve the above problems, the insect pest killing method according to the present invention includes a depressurization step of depressurizing an internal pressure of a storage container containing plants, crops, or grains, and an internal portion of the storage container after the depressurization process. A carbon dioxide injecting step for injecting carbon dioxide, and a concentration of carbon dioxide in the housing by returning the pressure inside the housing to the pressure before being decompressed in the decompressing step after the carbon dioxide injecting step. And a decompression step of adjusting the pressure to 40 vol% or more and 60 vol% or less, and the decompression step, the carbon dioxide injection step, and the decompression step are repeated one or more times.

  According to the present invention, since the pressure inside the container in which plants, crops, or grains are stored is reduced, and then carbon dioxide is injected into the container, carbon dioxide is injected into the plants, grains, and crops. It can be made easy to penetrate. Therefore, not only insects on the surfaces of plants, grains and crops can be killed, but also carbon dioxide can reach the insects lurking inside the plants, grains and crops to reliably kill them. In addition, after the carbon dioxide injecting step, there is provided a pressure reducing step in which the internal pressure of the storage is restored to the original pressure so that the concentration of carbon dioxide in the storage is from 40% by volume to 60% by volume. Therefore, it is possible to effectively kill insect pests without damaging growing plants or leafy vegetables.

  In the insect pest killing method of the present invention, the pressure reducing step is characterized in that the pressure inside the container is reduced to a pressure of 0.01 MPa or more and 0.07 MPa or less.

  According to this invention, insecticide can be performed by depressurizing the inside of the storage to an appropriate pressure according to the type of plant, crop, or grain stored in the storage.

  The insect pest killing method according to the present invention is characterized in that the decompression step is performed while stirring the atmosphere in the container.

  According to this invention, since the pressure-reducing step is carried out while stirring the atmosphere in the storage, the carbon dioxide injected into the storage is evenly diffused throughout the storage without being retained below the storage. Can be made. Therefore, it is possible to effectively kill insect pests attached to plants, crops, or grains housed on the upper side of the container.

  The insect pest killing method according to the present invention includes a leaving step of leaving for 12 hours or more and 24 hours or less in a state where the carbon dioxide is filled in the container after the decompression step. Is performed while stirring the atmosphere in the storage.

  According to the present invention, since the carbon dioxide is left in a state of being filled inside the container after the decompression process, the insecticide can be sufficiently killed only by the decompression process, the carbon dioxide injection process, and the decompression process. Even if it is not possible, carbon dioxide can be penetrated into the crop or grain, and the insect pests embedded in the crop or grain can be surely killed. Further, since the leaving step is performed while stirring the atmosphere in the storage, the carbon dioxide injected into the storage can be evenly diffused throughout the storage without being retained below the storage. Therefore, it is possible to effectively kill insect pests attached to plants, crops, or grains housed on the upper side of the container.

  According to the present invention, not only relatively hard crops but also pests on the surface of growing plants, relatively soft crops, etc. and pests lurking inside are damaged to plants, grains and crops. And can be effectively killed.

It is the flowchart which showed the process of the insecticide method of the pest concerning one Embodiment of this invention. It is the schematic which showed one example of the insecticidal apparatus which enforces the insecticidal method of the pest of this invention.

  Hereinafter, embodiments of the present invention will be described with reference to the drawings. The technical scope of the present invention is not limited only to the following description and drawings.

[Insecticide used]
First, an insecticidal apparatus 1 used in the insect pest killing method according to the present invention will be described with reference to FIG. In addition, the insecticidal apparatus 1 shown in FIG. 2 illustrates one of the insecticidal apparatuses that implement the insecticidal method according to the present invention. The insecticidal method according to the present invention is not limited to using the insecticidal apparatus 1 shown in FIG.

  A vacuum cooling device shown in FIG. 2 is used as the insecticidal apparatus 1 used for the insect pest-killing method. The insecticidal apparatus 1 includes a storage 10 in which plants, cereals, or agricultural products are stored, a suction path 20 that is connected to the storage 10 and sucks air in the storage 10, and a circulation path that circulates cooling water. 30 and a carbon dioxide supply unit 40 that supplies carbon dioxide to the inside of the storage 10. The container 10 further includes an outside air supply unit 60 for taking outside air into the container 10.

  The container 10 is a housing having an opening / closing door (not shown). The container 10 accommodates plants, cereals, or crops with the open / close door open, and closes the open / close doors to accommodate plants, cereals, or crops. The container 10 has high heat retaining properties and airtightness when the door is closed.

  The suction path unit 20 is connected to the steam ejector 21 connected to the storage case 10, the condenser 22 as a heat exchanger connected to the steam ejector 21, and connected to the condenser 22 by a pipe 24. Are provided, and a discharge port 25 for discharging the steam sucked by the vacuum pump 23 to the outside. The condenser 22 promotes the condensation of the negative pressure steam. As the vacuum pump 23, for example, a water ring vacuum pump is used. The suction path portion 20 controls the temperature inside the storage 10 to be lowered by discharging the air in the storage 10 from the storage 10 and reducing the pressure in the storage 10.

  The circulation path unit 30 includes a pump 31 for circulating the cooling water and a cooling unit 32 for cooling the circulating cooling water. The pump 31 and the cooling unit 32 are connected to the capacitor 22 by a pipe 33.

  The carbon dioxide supply unit 40 includes a cylinder 41 filled with carbon dioxide, a pipe 43 that connects the cylinder 41 and the storage 10, and an opening / closing valve 42 provided in the middle of the pipe 43. The carbon dioxide supply unit 40 supplies the carbon dioxide filled in the cylinder 41 to the inside of the storage case 10, thereby forming the inside of the storage case 10 at a desired carbon dioxide concentration.

  The outside air supply unit 60 includes an opening / closing valve 61 and a filter 62, and is provided so as to extend to the outside of the storage 10. The outside air supply unit 60 takes outside air into the storage 10 and restores the pressure inside the reduced storage 10 to the original pressure.

  The container 10 further measures a pressure sensor 51 that measures the pressure inside the container 10, a concentration sensor 52 that measures the concentration of carbon dioxide inside the container 10, and the ambient temperature inside the container 10. The temperature sensor 53 is provided. The pressure sensor 51, the concentration sensor 52, and the temperature sensor 53 are connected to the controller 50.

  The controller 50 operates the vacuum pump 23 provided in the suction path unit 20 based on a pressure signal in the storage 10 detected by the pressure sensor 51. The air in the storage 10 is discharged from the storage 10 by the operation of the vacuum pump 23. The pressure in the container 10 is reduced by such an action. Further, the open / close valve 61 of the outside air supply unit 60 is connected to the controller 50.

  The controller 50 issues a command to open and close the open / close valve 42 of the carbon dioxide supply unit 40. That is, the opening / closing valve 42 is opened based on a command from the controller 50. By opening the opening / closing valve 42, the carbon dioxide filled in the cylinder 41 is supplied into the storage 10. If the controller 50 determines that the carbon dioxide in the storage 10 has reached the set concentration based on the signal from the concentration sensor 52 after the carbon dioxide is injected into the storage 10, the controller 50 opens and closes. A command to close the valve 42 is transmitted to the open / close valve 42. The on-off valve 42 is closed according to this command, and stops supplying carbon dioxide to the storage 10.

  Further, the open / close valve 61 of the outside air supply unit 60 is connected to the controller 50. When the pressure inside the storage 10 is reduced and then restored to the original pressure, the outside air supply unit 60 opens the opening / closing valve 61 and takes in the outside air into the storage 10. At that time, the controller 50 controls the operation of the on-off valve 61 based on the signal from the pressure sensor 51 and the signal from the concentration sensor 52.

  The controller 50 further controls the temperature in the storage 10 by controlling the vacuum pump 23 provided in the suction path portion 20 based on a signal from the temperature sensor 53.

  In addition, the storage 10 includes a fan (not shown) that stirs the atmosphere in the storage 10. When the insecticidal apparatus 1 is used to kill insects, after injecting carbon dioxide into the container 10, the outside air is taken in and decompressed. Since carbon dioxide is heavier than air, when outside air is taken into the storage 10, the carbon dioxide stays below the storage 10. When carbon dioxide stays below the storage 10, the carbon dioxide does not sufficiently permeate the plants, grains, or farm products stored above the storage 10 and cannot be effectively killed. The fan stirs the atmosphere in the storage 10 to diffuse the carbon dioxide evenly throughout the storage 10. As a result, the fan has an insecticidal effect evenly in the entire storage 10.

[Basic process of insecticidal method]
The insect pest killing method according to the present invention is performed by the steps shown in the flowchart of FIG. This insect pest killing method includes a depressurizing step for depressurizing the pressure inside the storage 10 in which plants, crops, or grains are stored, and a carbon dioxide injection step for injecting carbon dioxide into the storage 10 after the depressurization step. Then, after the carbon dioxide injection step, the pressure inside the storage 10 is restored to the pressure before being reduced in the pressure reduction step, so that the concentration of carbon dioxide in the storage 10 is 40 volume% or more and 60 volume% or less. And a decompression process. Such a decompression process, a carbon dioxide injection process, and a decompression process are performed only once according to the type of plant, grain, or crop housed in the storage 10, or repeatedly performed a plurality of times.

  The method for killing pests according to the present invention can kill not only relatively hard crops such as grains, but also pests on the surface of growing plants and relatively soft crops, and pests lurking inside. There is a unique effect of being able to.

  Hereinafter, each process of the insect pest killing method of the present invention will be described.

(Decompression step)
The depressurization step is a step of depressurizing the pressure inside the storage 10 in which plants, crops, or grains are stored. The decompression step is performed by the vacuum pump 23 of the suction path unit 20 connected to the container 10. The vacuum pump 23 reduces the pressure in the storage 10 by sucking air existing in the storage 10.

  In the depressurization step, the boiling points of the plants, grains, and agricultural products stored in the storage 10 are lowered by lowering the pressure in the storage 10. Decreasing the boiling point can produce an effect that the food, grains, and crops stored in the storage 10 can be cooled in a short time. The method for killing pests according to the present invention utilizes the decompression of the interior of the storage 10 when the vacuum cooling device used as the insecticidal device 1 cools the plants, grains, and crops stored in the storage 10. Effective insecticidal action.

  In this decompression step, the pressure is reduced so that the pressure in the container 10 is 0.01 MPa or more and 0.07 MPa or less. However, in this decompression step, the pressure inside the storage 10 is reduced to an appropriate pressure according to the type of plant, grain, or agricultural product housed in the storage 10. For example, when a growing plant such as a plant seedling is accommodated and killed, the pressure inside the storage 10 is adjusted to 0.04 MPa or more and 0.07 MPa or less. Moreover, in the case of leafy vegetables such as cabbage and lettuce, the pressure inside the container 10 is adjusted to 0.02 MPa or more and 0.06 MPa or less. On the other hand, in the case of crops such as cereals, the pressure inside the storage 10 is adjusted to 0.01 MPa or more and 0.04 MPa or less. On the other hand, when accommodating and killing fruits containing a lot of water such as mandarin oranges and vegetables containing a lot of moisture such as tomato, the pressure inside the storage 10 is adjusted to 0.05 MPa or more and 0.07 MPa or less.

(CO2 injection process)
The carbon dioxide injection step is a step of injecting carbon dioxide into the container 10 after performing the decompression step. The injection of carbon dioxide into the storage 10 is performed by measuring the concentration of carbon dioxide in the storage 10 with the concentration sensor 52 provided in the storage 10, while the concentration of carbon dioxide in the storage 10 becomes a desired concentration. It is done until.

  When carbon dioxide is injected in a state where the inside of the container 10 is depressurized, carbon dioxide is more likely to penetrate into plants, cereals and crops than when carbon dioxide is injected at atmospheric pressure. Therefore, depressurization of the container 10 not only kills pests on the surface of plants, grains and crops, but also ensures that carbon dioxide reaches the pests lurking inside the plants, grains and crops. You can kill insects.

(Return pressure process)
The return pressure step is a step of returning the pressure inside the container 10 to the original pressure (atmospheric pressure) before being reduced in the pressure reduction step after the carbon dioxide injection step. The return pressure is performed by taking outside air into the storage 10 by the outside air supply unit 60 provided in the storage 10. Since the carbon dioxide already injected into the storage 10 is heavier than the taken-in air, the carbon dioxide stays below the storage 10. In order to prevent carbon dioxide from staying in the lower side of the storage case 10, the return pressure step may be performed while stirring the atmosphere in the storage case 10 with a fan or the like. By stirring the atmosphere in the storage 10, carbon dioxide does not stay below the storage 10, and the carbon dioxide is diffused throughout the storage 10.

  In this decompression step, when the pressure in the storage 10 is restored to the original pressure before being reduced in the decompression step, the concentration of carbon dioxide in the storage 10 is set to 40 vol% or more and 60 vol%. It is as follows. The action of insect pest killing on plants, cereals and crops begins to take place when the concentration of carbon dioxide injected into the container 10 reaches about 20% by volume. However, if the concentration of carbon dioxide is about 20% by volume lower than 40% by volume, it may be impossible to kill all pests on plants and crops. The pests on the crops are completely killed when the concentration reaches about 40% by volume or more. On the other hand, when the concentration of carbon dioxide exceeds 60% by volume, for example, when it reaches about 80% by volume, the injected carbon dioxide has an adverse effect on plants and crops. Therefore, carbon dioxide is preferably injected into the interior of the container 10 so that the concentration is 40% by volume or more and 60% by volume or less. However, the concentration of carbon dioxide in the storage 10 is set to an appropriate concentration according to the types of plants, cereals and agricultural products stored in the storage 10 and the types of pests to be killed.

  Note that the decompression process, the carbon dioxide injection process, and the decompression process may be performed only once or may be performed a plurality of times depending on the types of plants, grains, and crops.

  When a pest attached to a growing plant such as a plant seedling is killed, it is desirable to perform the decompression step, the carbon dioxide injection step and the decompression step only once in order not to damage the plant seedling. Moreover, since these plants often have pests attached only to the surface of the leaves, pests can be reliably killed by performing the decompression step, the carbon dioxide injection step, and the decompression step only once.

  When pests attached to leafy vegetables such as cabbage and lettuce are killed, the decompression step, the carbon dioxide injection step, and the decompression step may be repeated a plurality of times. Leafy vegetables such as cabbage and lettuce may have pests inside the vegetables as well as the outer surface. Such a pest is surely killed by repeating the decompression step and the carbon dioxide injection step a plurality of times. However, it is desirable to repeat the decompression step and the carbon dioxide injection step by limiting the number of times appropriately so as not to damage leafy vegetables such as cabbage and lettuce.

  When pests that have entered the interior of cereals and chestnuts are killed, they can be surely killed by repeating the decompression step, the carbon dioxide injection step, and the decompression step more times.

(Leave process)
The leaving step is a step that is performed as necessary, and is a step that is left for 12 hours or more and 24 hours or less in a state where carbon dioxide is filled in the container 10 after performing the decompression step. is there. In addition, in the case where the leaving step is performed by repeating the decompression step and the carbon dioxide injection step a plurality of times, not only the step is configured to be performed every time the carbon dioxide injection step is completed, but the decompression step and the carbon dioxide injection step The process can be configured to be performed only once after the process is repeated a plurality of times. This leaving step is performed while stirring the atmosphere in the storage 10 with a fan or the like, so that the carbon dioxide in the storage 10 can be evenly diffused throughout the storage 10.

DESCRIPTION OF SYMBOLS 1 Insecticide apparatus 10 Container 20 Suction path part 21 Steam ejector 22 Capacitor 23 Vacuum pump 24 Piping 30 Circulation path part 31 Pump 32 Cooling part 33 Piping 40 Carbon dioxide supply part 41 Cylinder 42 Opening / closing valve 43 Piping 50 Controller 51 Pressure sensor 52 Concentration Sensor 53 Temperature sensor 60 Outside air supply part 61 Open / close valve 62 Filter

Claims (4)

A depressurization step of depressurizing the internal pressure of the container in which plants, crops, or grains are stored;
A carbon dioxide injection step of injecting carbon dioxide into the container after the decompression step;
After the carbon dioxide injecting step, the pressure inside the container is restored to the pressure before being reduced in the pressure reducing step, so that the concentration of carbon dioxide in the container is 40 vol% or more and 60 vol% or less. A decompression process,
A method for killing pests, wherein the depressurizing step, the carbon dioxide injecting step, and the restoring pressure step are performed once or a plurality of times.   2. The method for killing insects according to claim 1, wherein the pressure reducing step reduces the internal pressure of the container to a pressure of 0.01 MPa or more and 0.07 MPa or less.   The insect repellent method according to claim 1 or 2, wherein the re-pressure process is performed while stirring the atmosphere in the storage. A leaving step of leaving for 12 hours to 24 hours in a state where the carbon dioxide is filled in the container after the pressure-reducing step;
The method for killing pests according to any one of claims 1 to 3, wherein the leaving step is performed while stirring the atmosphere in the storage.

Images