WO2018207667A1 - Method for producing agricultural crop - Google Patents

Abstract

[Problem] To provide a method for producing an agricultural crop, whereby it becomes possible to improve the quality of the agricultural crop. [Solution] The method for producing an agricultural crop includes: an aqueous solution preparation step of preparing a first aqueous solution containing sodium L-lactate; a plasma irradiation step of irradiating the first aqueous solution with atmospheric pressure plasma to prepare a second aqueous solution; and an aqueous solution feeding step of feeding the second aqueous solution to soil where the agricultural crop is to be grown. Alternatively, a part of the agricultural crop which contains a growth point may be directly irradiated with atmospheric pressure plasma instead of feeding the second aqueous solution.

Description

Crop production method

The technical field of this specification relates to a method for producing crops.

Plasma technology is applied in the fields of electricity, chemistry, and materials. Inside the plasma, ultraviolet rays and radicals are generated in addition to charged particles such as electrons and ions. These have been found to have various effects on living tissues, including sterilization of living tissues.

For example, Patent Document 1 discloses a technique for sterilizing microorganisms in water by irradiating water with plasma. Moreover, the plasma apparatus of patent document 1 can irradiate plasma in water, without flowing an electric current in water.

JP 2009-183867 A JP 2014-195450 A

By the way, in Patent Document 2, the number of viable yeast decreases when the yeast is irradiated with a large amount of atmospheric pressure plasma, but the number of viable yeast increases when the yeast is irradiated with a small amount of atmospheric pressure plasma. It is described to do. Thus, the possibility of activating and killing yeast by irradiation with plasma has been studied. However, the effects of plasma on other organisms are not always clear.

The technology of this specification has been made to solve the problems of the conventional technology described above. That is, the place made into the subject is providing the production method of the crop which aimed at improving the quality of the crop.

The method for producing a crop according to the first aspect includes an aqueous solution preparation step of preparing a first aqueous solution containing L-sodium lactate, and plasma irradiation that irradiates the first aqueous solution with atmospheric pressure plasma to form a second aqueous solution. And a step of supplying an aqueous solution to the soil on which the crop is grown.

In this crop production method, polyphenols can be increased inside the fruits of crops. Therefore, when a person eats this crop, the person becomes healthier.

In this specification, there is provided a method for producing crops that is intended to improve the quality of the crops.

It is a conceptual diagram for demonstrating the structure of the robot arm which scans the gas jet nozzle of the plasma generator of embodiment. FIG. FIG. 2A is a cross-sectional view showing the configuration of the first plasma generator, and FIG. B is a figure which shows the shape of an electrode. FIG. FIG. 3A is a cross-sectional view showing the configuration of the second plasma generator, and FIG. B is a partial cross-sectional view in a cross section perpendicular to the longitudinal direction of the plasma region. It is a figure which shows schematic structure of the 3rd plasma generator in embodiment. It is a schematic block diagram which shows the upper structure of the 3rd plasma generator in embodiment. It is a schematic block diagram which shows the lower structure of the 3rd plasma generator in embodiment. It is a figure for demonstrating the case where the 3rd plasma generator is irradiating plasma in embodiment. FIG. 6 is a diagram (No. 1) for describing an experiment method in Experiment A; FIG. 6 is a diagram (No. 2) for describing an experiment method in Experiment A; It is a graph which shows the quantity of the anthocyanin contained in a strawberry. It is a graph which shows the sugar content of a strawberry. It is a graph which shows the acidity of a strawberry. It is a graph which shows the sugar acid ratio of a strawberry.

Hereinafter, specific embodiments will be described with reference to the drawings, taking a method for producing crops as an example. As used herein, crops include fruits and vegetables.

(First embodiment)
A first embodiment will be described. In the crop production method of the first embodiment, a plasma activated aqueous solution is supplied to the soil of the crop. This plasma activated aqueous solution is obtained by irradiating an aqueous solution containing sodium lactate with plasma. Therefore, first, a plasma irradiation apparatus that irradiates plasma will be described.

1. Plasma activated aqueous solution production apparatus 1-1. Configuration of Plasma Activated Aqueous Solution Manufacturing Apparatus As shown in FIG. 1, the plasma activated aqueous solution manufacturing apparatus PM of the present embodiment includes a plasma irradiation apparatus P1 and an arm robot M1. The plasma irradiation apparatus P1 is for generating plasma and irradiating the plasma toward the solution.

As shown in FIG. 1, the arm robot M1 can move the position of the plasma irradiation apparatus P1 in each of the x-axis, y-axis, and z-axis directions. For convenience of explanation, the direction of plasma irradiation is the −z-axis direction. Thereby, the distance between the liquid level of a solution and the plasma irradiation apparatus P1 can be adjusted. Moreover, this plasma activated aqueous solution manufacturing apparatus PM can irradiate plasma only for the time by setting plasma irradiation time beforehand.

There are three types of plasma irradiation apparatus P1 (a first plasma generation apparatus P10, a second plasma generation apparatus P20, and a third plasma generation apparatus P30), as will be described later. Any method may be used. The third plasma generator P30 does not have the robot arm M1 shown in FIG.

1-2. First plasma generator FIG. A is a cross-sectional view showing a schematic configuration of the plasma generator P10. Here, the plasma generator P10 is a first plasma generator that ejects plasma in the form of dots. FIG. B is shown in FIG. It is a figure which shows the detail of the shape of the electrodes 2a and 2b of the plasma generator P10 of A.

The plasma generating apparatus P10 includes a casing unit 10, electrodes 2a and 2b, and a voltage application unit 3. The casing 10 is made of a sintered body made of alumina (Al ₂ O ₃ ) as a raw material. And the shape of the housing | casing part 10 is a cylinder shape. The internal diameter of the housing | casing part 10 is 2 mm or more and 3 mm or less. The thickness of the housing | casing part 10 is 0.2 mm or more and 0.3 mm or less. The length of the housing | casing part 10 is 10 cm or more and 30 cm or less. A gas inlet 10 i and a gas outlet 10 o are formed at both ends of the housing 10. The gas inlet 10i is for introducing a gas for generating plasma. The gas outlet 10 o is an irradiation unit for irradiating the outside of the housing unit 10 with plasma. The direction in which the gas moves is the direction of the arrow in the figure.

The electrodes 2a and 2b are a pair of opposed electrodes arranged to face each other. The lengths of the electrodes 2 a and 2 b in the facing surface direction are smaller than the inner diameter of the housing portion 10. For example, it is about 1 mm. For the electrodes 2a and 2b, FIG. As shown to B, many recessed parts (hollow) H are formed in each of an opposing surface. Therefore, the opposing surfaces of the electrodes 2a and 2b have a fine uneven shape. In addition, the depth of this recessed part H is about 0.5 mm.

The electrode 2a is disposed inside the casing 10 and in the vicinity of the gas inlet 10i. The electrode 2b is disposed inside the housing portion 10 and in the vicinity of the gas ejection port 10o. Therefore, in the plasma generator P10, gas is introduced from the opposite side of the facing surface of the electrode 2a, and the gas is ejected to the opposite side of the facing surface of the electrode 2b. The distance between the electrodes 2a and 2b is, for example, 24 cm. The distance between the electrodes 2a and 2b may be a smaller distance.

The voltage application unit 3 is for applying an alternating voltage between the electrodes 2a and 2b. The voltage application unit 3 boosts the voltage to 9 kV using 60 Hz and 100 V, which are commercial AC voltages, and applies a voltage between the electrodes 2 a and 2 b.

When argon is introduced from the gas introduction port 10 i and a voltage is applied between the electrodes 2 a and 2 b by the voltage application unit 3, plasma is generated inside the housing unit 10. FIG. A region where plasma is generated is defined as a plasma generation region P as indicated by the hatched line A in FIG. The plasma generation region P is covered with the casing unit 10.

1-3. Second plasma generator FIG. A is a sectional view showing a schematic configuration of the plasma generator P20. Here, the plasma generator P20 is a second plasma generator that ejects plasma linearly. FIG. B is shown in FIG. It is a fragmentary sectional view in the cross section perpendicular | vertical to the longitudinal direction of the plasma area | region P of the plasma generator P20 of A. FIG.

The plasma generating apparatus P20 includes a casing unit 11, electrodes 2a and 2b, and a voltage application unit 3. The casing 11 is made of a sintered body using alumina (Al ₂ O ₃ ) as a raw material. At both ends of the housing portion 11, a gas introduction port 11 i and a large number of gas ejection ports 11 o are formed. The gas inlet 11i is shown in FIG. It has a slit shape with the left-right direction of A as the longitudinal direction. The slit width (the width in the left-right direction in FIG. 3.B) from the gas inlet 11i to just above the plasma region P is, for example, 1 mm.

The gas outlet 11o is an irradiation unit for irradiating the outside of the casing 11 with plasma. The gas ejection port 11o has a cylindrical shape or a slit shape. The gas outlet 11o in the case of a cylindrical shape is formed in a straight line along the longitudinal direction of the plasma region. The inner diameter of the gas ejection port 11o is in the range of 1 mm to 2 mm. In the case of a slit shape, the slit width of the gas ejection port 11o is preferably 1 mm or less. Thereby, a stable plasma is formed. The gas inlet 11i introduces gas in a direction intersecting with a line connecting the electrode 2a and the electrode 2b.

The electrodes 2a and 2b and the voltage application unit 3 are the same as those of the plasma generator P10 shown in FIG. Similarly, a voltage is applied between the electrodes 2a and 2b using a commercial AC voltage. Thereby, plasma can be ejected in a straight line.

Also, a plasma generator P20 that ejects plasma in a straight line is shown in FIG. If arranged in a line in the left-right direction of B, the plasma can be ejected in a plane over a rectangular region.

1-4. Third Plasma Generator FIG. 4 is a conceptual diagram showing a schematic configuration of a third plasma generator P30. The plasma generator P30 is for irradiating the contained solution with plasma.

As shown in FIG. 4, the plasma generator P30 includes a first electrode 110, a second electrode 210, a first potential applying unit 120, a second potential applying unit 220, and a first lead wire 130. The second lead wire 230, the gas supply unit 140, the gas pipe coupling connector 150, the gas pipe 160, the first electrode protection member 170, the second electrode protection member 240, and the first electrode support member 180. , A sealing member 191, a coupling member 192, a container 250, a sealing member 260, and a mount 270.

1-4-1. Schematic Configuration of Electrode The first electrode 110 has a cylindrical portion 110a. The plasma gas can be supplied into the cylindrical portion 110a. That is, the inside of the first electrode 110 communicates with the gas supply unit 140. The first electrode 110 blows gas from the cylindrical portion 110a toward the second electrode 210. And the front-end | tip part of the 1st electrode 110 is carrying out the injection needle shape. That is, the tip of the first electrode 110 has an inclined surface that is inclined with respect to a direction perpendicular to the axial direction of the first electrode 110. A micro hollow is formed at the tip of the first electrode 110.

The second electrode 210 is an electrode facing the first electrode 110. The second electrode 210 is a rod-shaped electrode. The second electrode 210 has a cylindrical shape. Alternatively, it may be a polygonal column shape. Alternatively, it may have a needle shape with a sharp tip. Here, the second electrode 210 has a tip portion 211. The tip portion 211 of the second electrode 210 is made of an iridium alloy containing iridium. For example, an alloy of iridium and platinum. Alternatively, an alloy of iridium, platinum, and osmium. The iridium alloy has high hardness and excellent heat resistance. Therefore, the iridium alloy is suitable for the tip portion 211 of the second electrode 210. Further, platinum may be used instead of iridium. Alternatively, palladium may be used. Alternatively, it may be a metal or alloy containing at least one of iridium, platinum, and palladium. Further, the tip 211 of the second electrode 210 may be gold. Further, at the time of discharging, the second electrode 210 is immersed in the solution stored in the container 250.

The first potential applying unit 120 is for applying a periodically changing potential to the first electrode 110. The second potential applying unit 220 is for applying a periodically changing potential to the second electrode 210. Here, one of the first potential applying unit 120 and the second potential applying unit 220 may be grounded. The first lead wire 130 is for electrically connecting the first electrode 110 and the first potential applying unit 120. The first lead wire 130 may be a nickel alloy or stainless steel. The second lead wire 230 is for electrically connecting the second electrode 210 and the second potential applying unit 220. The second lead wire 230 may be a nickel alloy or stainless steel. As a result, a high-frequency voltage is applied between the first electrode 110 and the second electrode 210. That is, the first potential application unit 120 and the second potential application unit 220 are voltage application units for applying a voltage between the first electrode 110 and the second electrode 210.

1-4-2. Gas Supply Path As described above, the plasma generation apparatus P30 includes the gas supply unit 140, the gas pipe coupling connector 150, and the gas pipe 160. Therefore, the gas supply unit 140 supplies plasma gas to the inside of the cylindrical portion of the first electrode 110 via the gas pipe 160 and the gas pipe coupling connector 150. Here, the gas supply unit 160 supplies, for example, Ar gas. Alternatively, other rare gas may be supplied. Alternatively, a trace amount of other gases such as oxygen gas may be included. Therefore, the plasma gas is sprayed from the first electrode 110 toward the solution stored in the solution 250.

1-4-3. Configuration of Upper Structure FIG. 5 is a diagram showing an upper structure of the plasma generator P30. As shown in FIG. 5, the first electrode 110 has a tip 111. As shown in FIG. 4, the distal end portion 111 is disposed at a position facing the second electrode 210. The tip 111 of the first electrode 110 has an inclined surface 111a. The inclined surface 111 a is a surface that is inclined with respect to a surface perpendicular to the axial direction of the first electrode 110. In addition, a micro hollow 111b is formed at the tip 111. The micro hollow 111b is a minute recess having a length of 0.5 mm to 1 mm and a width of 0.3 mm to 0.5 mm.

As described above, the plasma generator P30 includes the sealing member 191 and the coupling member 192. The sealing member 191 is attached to the container 250 shown in FIG. 4 and seals the inside of the container 250. The coupling member 192 is a member for connecting the first electrode 110 and the gas pipe coupling connector 150 via the sealing member 191 or the like.

1-4-4. Configuration of Lower Structure FIG. 6 is a diagram showing a lower structure of the plasma generator P30. As described above, the plasma generator P30 includes the container 250, the sealing member 260, and the gantry 270. The container 250 can accommodate a solution therein. Here, the solution includes an aqueous solution and an organic solvent. The container 250 houses the first electrode 110 and the second electrode 210 therein. Moreover, the container 250 is good to have a scale. This is for measuring the amount of the solution stored in the container 250.

The sealing member 260 is for closing the gap between the second electrode protection member 240 and the container 250. An example of the sealing member 260 is O-ring. Other members may be applied as long as the sealing property of the container 250 is ensured and the solution prevents the solution from leaking to the bottom of the container 250. The gantry 270 is for supporting the container 250 and other members.

2. 2. Plasma generated by plasma generator 2-1. The first plasma generator and the second plasma generator The plasma generated by the plasma generators P10 and P20 is non-equilibrium atmospheric pressure plasma. Here, atmospheric pressure plasma refers to plasma having a pressure in the range of 0.5 to 2.0 atmospheres.

In this embodiment, Ar gas is mainly used as the plasma generating gas. Of course, electrons and Ar ions are generated in the plasma generated by the plasma generators P10 and P20. Ar ions generate ultraviolet rays. Further, since this plasma is released into the atmosphere, it generates oxygen radicals, nitrogen radicals, and the like.

The plasma density of this plasma is in the range of 1 × 10 ¹⁴ cm ^{−3 to} 1 × 10 ¹⁷ cm ⁻³ . The plasma density in the plasma generated by the dielectric barrier discharge is about 1 × 10 ¹¹ cm ^{−3 to} 1 × 10 ¹³ cm ⁻³ . Therefore, the plasma density of the plasma generated by the plasma generators P10 and P20 is about three orders of magnitude higher than the plasma density of the plasma generated by the dielectric barrier discharge. Therefore, more Ar ions are generated inside the plasma. Therefore, the amount of radicals and ultraviolet rays is also large. This plasma density is approximately equal to the electron density inside the plasma.

And the plasma temperature at the time of this plasma generation is in the range of about 1000K to 2500K. Moreover, the electron temperature in this plasma is larger than the gas temperature. Moreover, although the electron density is in the range of 1 × 10 ¹⁴ cm ^{−3 to} 1 × 10 ¹⁷ cm ⁻³ , the gas temperature is in the range of about 1000 K to 2500 K. The temperature of this plasma is the temperature in the plasma generation region P where plasma is generated. Therefore, the plasma temperature at the position of the liquid level can be set to about room temperature by setting the plasma conditions and the distance from the gas outlet to the water surface to be different.

2-2. Third Plasma Generating Device FIG. 7 is a diagram schematically showing how the plasma generating device P30 generates plasma. The plasma generated by the plasma generator P30 is non-equilibrium atmospheric pressure plasma.

As shown in FIG. 7, the plasma gas supplied from the gas supply unit 140 is released from the first electrode 110 in the direction of the arrow K1. When a high frequency voltage is applied between the first electrode 110 and the second electrode 210, a plasma generation region PG1 is formed between the first electrode 110 and the second electrode 210. The plasma generation region PG1 in FIG. 7 is drawn conceptually.

When the first potential applying unit 120 and the second potential applying unit 220 apply a voltage between the first electrode 110 and the second electrode 210, the second electrode 210 is disposed inside the liquid. ing. As described above, between the first electrode 110 and the second electrode 210, there are the liquid stored in the container 250 and the atmosphere. A line connecting the first electrode and the second electrode intersects the liquid level LL1 of the liquid.

Therefore, plasma is generated between the liquid level LL 1 of the liquid and the first electrode 110. At this time, the liquid level LL1 of the liquid is recessed toward the liquid side due to the wind pressure of the plasma gas discharged from the first electrode 110 in the direction of the arrow K1. Then, the solution is partially electrolyzed and vaporized inside the liquid. Plasma is also generated inside the vaporized gas. Plasma generation region PG1 is in contact with liquid level LL1.

As a result, radicals derived from the atmosphere or water are generated. And a radical will be irradiated to a solution. Thereby, radicals react with water molecules or solutes in solution.

3. 3. Method for producing plasma activated aqueous solution 3-1. Aqueous solution preparation step First, a first aqueous solution is prepared. The first aqueous solution refers to an aqueous solution before being irradiated with plasma. The first aqueous solution contains L-sodium lactate, sodium chloride, potassium chloride, and calcium chloride.

3-2. Plasma Irradiation Step Next, the first aqueous solution is irradiated with atmospheric pressure plasma generated in the plasma generation region by the plasma activated aqueous solution manufacturing apparatus PM. The distance between the liquid surface and the plasma outlet when the plasma is irradiated is, for example, 3 mm. Further, this distance may be changed within a range of 0.1 cm to 3 cm, for example. The plasma density in the plasma generation region is in the range of 1 × 10 ¹⁴ cm ^{−3 to} 1 × 10 ¹⁷ cm ⁻³ . And the plasma temperature in this plasma exists in the range of about 1000K or more and 2500K or less. However, the plasma temperature can be lowered to about room temperature (about 300 K) at the liquid level. These plasma conditions are shown in Table 1. These conditions are merely examples.

[Table 1]
Conditions Numerical range Liquid level-outlet distance 0.1 cm or more 3 cm or less Plasma density 1 x 10 ¹⁴ cm ^-3 or more 1 x 10 ¹⁷ cm ^-3 or less Plasma temperature 1000 K or more 2500 K or less

Thus, the first aqueous solution is changed to the second aqueous solution by irradiating the first aqueous solution with atmospheric pressure plasma. It is considered that the components of the first aqueous solution react with radicals derived from the plasma by irradiation with atmospheric pressure plasma. Further, nitrite ions and nitrate ions increase in the aqueous solution. The components of the first aqueous solution are considered to react with these ions and the like. This second aqueous solution is a plasma-activated aqueous solution that increases polyphenols contained in agricultural products.

The plasma density of the atmospheric pressure plasma is, for example, 2 × 10 ¹⁶ cm ⁻³ . The irradiation time of atmospheric pressure plasma is, for example, not less than 30 seconds and not more than 600 seconds. The volume of the first aqueous solution at the time of irradiation with atmospheric pressure plasma is, for example, 10 ml or more and 1000 ml or less.

In this case, the plasma density time product per unit volume in the second aqueous solution is 6 × 10 ¹⁴ sec · cm ⁻³ · ml ⁻¹ or more and 1.2 × 10 ¹⁸ sec · cm ⁻³ · ml ⁻¹ or less. It is. Here, the plasma density time product per unit volume is (plasma density) × (irradiation time) / (volume of the first aqueous solution). That is, the plasma density time product per unit volume is the amount of plasma product irradiated to the first aqueous solution per unit volume.

4). Effect of Plasma Activated Aqueous Solution The plasma activated aqueous solution of the present embodiment is obtained by irradiating an aqueous solution containing L-sodium lactate with plasma. More specifically, the first aqueous solution containing L-sodium lactate, sodium chloride, potassium chloride, and calcium chloride is irradiated with atmospheric pressure plasma. As will be described later, this plasma activated aqueous solution increases the amount of polyphenols contained in agricultural products. Polyphenols are a kind of antioxidant. More specifically, the increasing polyphenols are anthocyanins. Therefore, people who eat this crop will be healthier. In addition, the color of fruits and the like is good.

5). Production method of agricultural product using plasma activated aqueous solution The production method of agricultural product of this embodiment includes an aqueous solution preparation step of preparing a first aqueous solution containing L-sodium lactate, and irradiating the first aqueous solution with atmospheric pressure plasma. And a plasma irradiation step for forming a second aqueous solution, and an aqueous solution supply step for supplying the second aqueous solution to the soil on which the crop is grown.

5-1. As described above, in the aqueous solution preparation step, a first aqueous solution containing L-sodium lactate, sodium chloride, potassium chloride, and calcium chloride is prepared.

5-2. Plasma irradiation process Next, a plasma irradiation process is performed. As described above, in this step, the first aqueous solution is irradiated with atmospheric pressure plasma to form a second aqueous solution.

5-3. Aqueous solution supply step Next, an aqueous solution supply step is performed. In this step, the second aqueous solution is supplied to the soil of the crop. At this time, the second aqueous solution is added at a concentration of 5 to 1000 times the total volume. The plasma density time product per unit volume in the aqueous solution supplied to the soil is 6 × 10 ¹¹ sec · cm ⁻³ · ml ^{−1 to} 2.4 × 10 ¹⁷ sec · cm ⁻³ · ml ⁻¹ . The dilution rate of the second aqueous solution is preferably 25 times or more and 500 times or less. Of course, fertilizer and water are separately supplied to the soil of the crops.

6). Modification 6-1. Third Plasma Generator The plasma generator P30 may be used when manufacturing the plasma activated aqueous solution. For this purpose, the first aqueous solution is irradiated with atmospheric pressure plasma generated in the plasma generation region by the plasma generator P30. The first electrode 110 is disposed outside the first aqueous solution, and the second electrode 210 is disposed in the first aqueous solution. Then, the gas is irradiated from the cylindrical portion 110a of the first electrode 110 toward the first aqueous solution. In this state, a voltage is applied between the first electrode 110 and the second electrode 210.

6-2. First Electrode of Third Plasma Generator In the plasma generator P30 of the present embodiment, the cylindrical portion 110a of the first electrode 110 has a cylindrical shape. However, it is not limited to a cylindrical shape. As long as it is cylindrical, it may be polygonal.

6-3. Miniaturized plasma generators The plasma generators P10, P20, etc. may be further miniaturized. By sufficiently downsizing, a pen-type plasma generator can be manufactured. Even in that case, a plasma density equivalent to that of the plasma generators P10 and P20 can be obtained.

6-4. Freezing step In addition, a freezing step may be performed to store the second aqueous solution. The freezing step is performed after the plasma irradiation step and before the aqueous solution supply step. In the freezing step, the second aqueous solution is frozen within a range of −196 ° C. to 0 ° C. Specifically, it stores in a freezer. As the freezer, for example, a biological laboratory refrigerator (for example, BioFreezer GS-5203KHC manufactured by Nippon Freezer Co., Ltd.) can be used.

The storage temperature of the second aqueous solution frozen in this freezer is in the range of −28 ° C. or higher and −14 ° C. or lower. Further, the storage temperature of the second aqueous solution is not limited to this range. Any ordinary freezing temperature may be used. For example, it is within a range of −196 ° C. or more and 0 ° C. or less. Preferably, it is −196 ° C. or more and −10 ° or less. More preferably, it is −150 ° C. or higher and −20 ° C. or lower. More preferably, it is −80 ° C. or higher and −30 ° C. or lower.

By performing this freezing step, the plasma activated aqueous solution can be stored. Therefore, the frozen plasma activated aqueous solution may be thawed before being supplied to the soil of the agricultural crop.

6-5. Numerical values of the plasma generator The numerical ranges of the first plasma generator P10 and the second plasma generator P20 are examples. Therefore, the present invention can be applied without being limited to the numerical range in the present embodiment.

6-6. Combination You may combine suitably the modification of 1st Embodiment.

7). Summary of this embodiment As described in detail above, the plasma-activated aqueous solution of this embodiment is obtained by irradiating the first aqueous solution containing L-sodium lactate with plasma. When this plasma-activated aqueous solution is supplied to the crop soil, the polyphenols in the crop increase.

(Second Embodiment)
A second embodiment will be described. In the second embodiment, the plasma activated aqueous solution of the first embodiment is not used. Instead, in the second embodiment, the atmospheric crop is directly irradiated with the atmospheric pressure plasma. As the atmospheric pressure plasma apparatus, the same one as in the first embodiment can be used. Therefore, differences from the first embodiment will be described.

1. Crop production method 1-1. Plasma irradiation process In this plasma irradiation process, the atmospheric pressure plasma is directly irradiated to the region including the growth point of the crop. Here, the growth point is a location where the cell division is actively performed while being located near the tip of the plant stem. The distance between the plasma irradiation port and the growth point of the crop is, for example, 0 cm or more and 10 cm or less. Moreover, it is preferable that the plasma irradiation port faces the growth point of the crop.

The plasma density is the same as in the first embodiment. The plasma irradiation time is, for example, 30 seconds to 600 seconds. For example, when the plasma density of the atmospheric pressure plasma is 2 × 10 ¹⁶ cm ⁻³ , the plasma density time product, which is the product of the plasma density of the atmospheric pressure plasma and the irradiation time, is 6 × 10 ¹⁷ sec · cm ⁻³ or more and 1 2 × 10 ¹⁹ sec · cm ⁻³ or less.

2. Effect of Directly Irradiating Agricultural Products with Agricultural Products By irradiating a region including the growth point of agricultural products with atmospheric pressure plasma, the amount of polyphenols contained in the agricultural products increases as will be described later. More specifically, the increasing polyphenols are anthocyanins. Therefore, people who eat this crop will be healthier.

Thus, by directly irradiating the region including the growth point of the crop with atmospheric pressure plasma, atoms / molecules, ions, radicals, etc. derived from nitrogen atoms or oxygen atoms are supplied to the growth point of the crop. As a result, crops are expected to spontaneously enhance their antioxidant effects against such external stimuli. As a result, it is considered that many antioxidant substances such as polyphenols are produced in the fruit of the fruit.

1. Experiment A
1-1. Crop (strawberry)
In this experiment, strawberries were cultivated as agricultural crops. Strawberry variety is Red Hoppe (registered trademark). Here, strawberry seedlings with flower buds were planted inside the greenhouse.

1-2. Production of Plasma Activated Aqueous Solution The plasma activated aqueous solution in this experiment is a solution (PAL: Plasma Activated Lactec (Lactec is a registered trademark)) in which an aqueous solution having the same components as Lactec (registered trademark) is irradiated with plasma. Lactec (registered trademark) is a lactated Ringer's solution containing sodium chloride, potassium chloride, calcium chloride, and L-sodium lactate. The concentration of sodium chloride is 6.0 g / L. The concentration of potassium chloride is 0.3 g / L. The concentration of calcium chloride hydrate is 0.2 g / L. The concentration of L-sodium lactate is 3.1 g / L.

As the plasma device, a plasma generator P20 was used. The plasma irradiation time was 5 minutes per time. Argon gas was used as the type of gas. In the plasma generator P20, the distance between the plasma generation region and the first aqueous solution was 2 mm. The plasma density in the plasma generator P20 was 2 × 10 ¹⁶ cm ⁻³ .

1-3. Supply of Plasma Activated Aqueous Solution As shown in FIG. 8, a plasma activated aqueous solution (PAL) was supplied to the soil of strawberry planted. A pipe for water distribution was placed on the planted strawberry seedling, and the plasma activated aqueous solution was sprayed from the through hole of the pipe. Moreover, in order to compare experimental effects, other aqueous solutions were sprayed.

Table 2 is a table showing grouping of strawberry seedlings. As shown in Table 2, many strawberry seedlings were grouped and supplied with different supplies. Of course, the same amount of water and fertilizer was given to all groups. That is, Table 2 is a table extracted for supplies and the like that are different for each group among those given inside the same greenhouse. Group A is given nothing other than normal water and fertilizer. Group C was given distilled water in the same amount as the aqueous solution given in Group DG. That is, the amount of water in group C is greater than the amount of water in group A.

1-4. Direct irradiation of plasma In group B, the strawberry seedlings were directly irradiated with plasma. In that case, the plasma was irradiated toward the growth point in the strawberry seedling. The distance between the growth point of the strawberry and the irradiation port of the plasma irradiation apparatus is about 3 cm. Therefore, the plasma is irradiated to a region including the growth point of strawberry. In addition, helium gas was used as plasma gas.

FIG. 9 is a diagram showing a state in which plasma is directly irradiated onto strawberries. Here, the growth points of the strawberry are scattered around the apex of the stem part where the leaf part of the strawberry grows.

In addition, about the plasma activation aqueous solution and the direct irradiation of plasma, 2 sets were performed twice a day, and 3 sets were implemented per week. That is, the plasma was irradiated 6 times a week.

[Table 2]
Group Supply, etc. Dilution rate Group A No addition (ctrl)-
Group B Plasma direct irradiation-
Group C distilled water-
Group D Lactec (registered trademark) 100-fold diluted Group E Plasma activated aqueous solution 100-fold diluted Group F Lactec (registered trademark) 25-fold diluted Group G Plasma-activated aqueous solution 25-fold diluted

1-5. Experimental Results FIG. 10 is a graph showing the amount of anthocyanins contained in harvested strawberries. As shown in FIG. 10, the anthocyanin content of group A was about 16 mg / 100 g. Group B had an anthocyanin content of about 20 mg / 100 g. Group C anthocyanin content was about 16 mg / 100 g. Group D anthocyanin content was about 13 mg / 100 g. Group E has an anthocyanin content of about 18 mg / 100 g. The anthocyanin content of Group F was about 12 mg / 100 g. Group G has an anthocyanin content of about 19 mg / 100 g.

As shown in FIG. 10, even if the error is taken into consideration, the group B directly irradiated with plasma and the groups E and G supplied with PAL are more in comparison with the other groups not supplied with plasma components. Contains a lot of anthocyanins.

When comparing group A and group B, the anthocyanin content of group B is increased by about 25% by direct plasma irradiation. Here, the amounts of water and fertilizer given to Group A and Group B are comparable.

When comparing Group E and Group D, the anthocyanin content of Group E given PAL is increased by about 45%. The content of anthocyanins in group D given Lactec® is reduced by about 18% compared to group C given distilled water. That is, the component of LACTEC (registered trademark) itself has an effect of reducing the content of anthocyanins. However, PAL activated by irradiating with plasma has the effect of increasing the content of anthocyanins. In addition, the content of anthocyanins of group E given PAL was about 13% higher than the content of anthocyanins of group C given distilled water.

When comparing Group G and Group F, the anthocyanin content of Group G given PAL has increased by about 55%. The content of anthocyanins in group F given Lactec® is reduced by about 18% compared to group C given distilled water. Thus, the same tendency was obtained irrespective of the degree of dilution of LACTEK (registered trademark). In addition, the content of anthocyanins of group G given PAL was about 19% higher than the content of anthocyanins of group C given distilled water.

1-6. Discussion As described above, it is considered that the substance derived from the plasma product acted on the strawberry in the group B in which the region including the growth point of the strawberry was irradiated with the plasma and the groups E and G to which the PAL was supplied. For example, it can be considered that reactive oxygen species (ROS) and the like act on the growth point of strawberry, so that strawberry seedlings have increased anthocyanins, which are a kind of antioxidant, in order to counter active oxygen species.

2. Experiment B
2-1. Sample Preparation An experiment was performed by preparing a sample in the same manner as in Experiment A. At that time, nine types of samples were prepared as shown in Table 3. Table 3 is a table showing grouping of strawberry seedlings. Similar to Table 2, Table 3 is a table in which different supplies and the like are extracted for each group.

Here, group B1 is a sample directly irradiated with plasma for 30 seconds per time in the first and second stages of strawberry seedling cultivation. Group B2 is a sample directly irradiated with plasma for 120 seconds per time in the first and second stages of strawberry seedling cultivation. Group B3 is a sample additionally prepared in the later stage of strawberry seedling cultivation. Therefore, group B3 summarizes only the late data of strawberry seedling cultivation.

In addition, about the plasma activation aqueous solution and the direct irradiation of plasma, 2 sets were performed twice a day, and 3 sets were implemented per week. That is, the plasma was irradiated 6 times a week.

[Table 3]
Group Supply, etc. Dilution rate Group A No addition (ctrl)-
Group B1 Plasma direct irradiation (30 seconds)-
Group B2 Plasma direct irradiation (120 seconds)-
Group B3 Plasma direct irradiation (late stage, 120 seconds)-
Group C Distilled water (DW)-
Group D Lactec (registered trademark) 100-fold diluted Group E Plasma activated aqueous solution 100-fold diluted Group F Lactec (registered trademark) 25-fold diluted Group G Plasma-activated aqueous solution 25-fold diluted

2-2. Experimental result 2
FIG. 11 is a graph showing the sugar content of strawberries. As shown in FIG. 11, the sugar content of group A (no irradiation) was about 11.6%. The sugar content of Group B1 (30 seconds direct irradiation) was about 12.3%. The sugar content of Group B2 (120 seconds direct irradiation) was about 11.8%. The sugar content of Group B3 (late cultivation period, direct irradiation for 120 seconds) was about 12.3%. The sugar content of Group C (distilled water) was about 11.8%. The sugar content of Group D (100 times unirradiated) was about 12.1%. The sugar content of Group E (100-fold PAL) was about 11.9%. The sugar content of Group F (25 times unirradiated) was about 11.4%. The sugar content of group G (25-fold PAL) was about 11.4%.

As shown in FIG. 11, the sugar content of group B1-B3 that is directly irradiated with plasma is higher than that of group A that is not irradiated with plasma. Compared to distilled water (group C), the sugar content of groups D and E diluted 100 times tends to be slightly higher, and the sugar content of groups F and G diluted 25 times tends to be slightly lower. Moreover, as a whole, compared to Group A, the sugar content of strawberries that are directly irradiated with plasma or supplied with PAL tends to be higher.

FIG. 12 is a graph showing the acidity of strawberries. As shown in FIG. 12, the acidity of group A (no irradiation) was about 0.69%. The acidity of group B1 was about 0.70%. The acidity of group B2 was about 0.66%. The acidity of group B3 was about 0.67%. The acidity of Group C was about 0.64%. The acidity of group D was about 0.66%. The acidity of Group E was about 0.65%. The acidity of Group F was about 0.66%. The acidity of group G was about 0.61%.

As shown in FIG. 12, the acidity of group B1-B3 that is directly irradiated with plasma tends to be lower than the acidity of group A that is not irradiated with plasma. Moreover, the acidity of the groups E and G to which PAL is supplied tends to be lower than that of the groups A and C. The acidity of group G was the lowest.

FIG. 13 is a graph showing the sugar acid ratio of strawberries. The sugar acid ratio is sugar / acidity. As shown in FIG. 13, the group A sugar acid ratio was about 16.8. The sugar acid ratio of group B1 was about 17.6. The sugar acid ratio of group B2 was about 17.8. The sugar acid ratio of group B3 was about 18.7. The sugar acid ratio of group C was about 18.5. The sugar acid ratio of Group D was about 18.4. The sugar acid ratio of Group E was about 18.4. The sugar acid ratio of Group F was about 17.5. The sugar acid ratio of group G was about 18.7.

As shown in FIG. 13, the saccharide acid ratio of group B1-B3 that is directly irradiated with plasma is sufficiently higher than that of group A that is not irradiated with plasma. The ratio of sugar acids in groups E and G using PAL is sufficiently higher than that in group A.

Thus, the sugar acid ratio of strawberries increases by irradiating with plasma.

A. Additional Notes The method for producing a crop according to the first aspect includes an aqueous solution preparation step of preparing a first aqueous solution containing L-sodium lactate, and plasma that is irradiated with atmospheric pressure plasma to form a second aqueous solution. An irradiation step, and an aqueous solution supply step of supplying a second aqueous solution to the soil on which the crop is grown.

In the crop production method according to the second aspect, in the aqueous solution supplying step, the plasma density time product per unit volume in the second aqueous solution is 6 × 10 ¹¹ sec · cm ⁻³ · ml ⁻¹ or more and 2.4 × 10. ¹⁷ sec · cm ^-3 · ml ^-1 or less

The crop production method according to the third aspect includes a freezing step of freezing the second aqueous solution. In the freezing step, the second aqueous solution is frozen within a range of −196 ° C. to 0 ° C.

In the crop production method according to the fourth aspect, the atmospheric pressure plasma is directly irradiated onto the region including the growth point of the crop.

In the crop production method according to the fifth aspect, the plasma density time product, which is the product of the plasma density of the atmospheric pressure plasma and the irradiation time, is 6 × 10 ¹⁷ sec · cm ⁻³ or more and 1.2 × 10 ¹⁹ sec · cm ⁻³ or less.

P1 ... Plasma irradiation apparatus M1 ... Robot arm PM ... Plasma activated aqueous solution manufacturing apparatus P10, P20, P30 ... Plasma generators 10, 11 ... Case parts 10i, 11i ... Gas inlets 10o, 11o ... Gas outlets 2a, 2b ... electrode P ... plasma region H ... recess (hollow)
DESCRIPTION OF SYMBOLS 110 ... 1st electrode 120 ... 1st electric potential provision part 130 ... 1st lead wire 140 ... Gas supply part 150 ... Gas pipe coupling connector 160 ... Gas pipe 170 ... 1st electrode protection member 210 ... 2nd electrode 220 ... 2nd electrode Two potential applying units 230 ... second lead wire 240 ... second electrode protection member 250 ... container 260 ... sealing member 270 ... mount

Claims (5)

An aqueous solution preparation step of preparing a first aqueous solution containing L-sodium lactate;
A plasma irradiation step of irradiating the first aqueous solution with atmospheric pressure plasma to form a second aqueous solution;
An aqueous solution supplying step of supplying the second aqueous solution to the soil on which the crop is grown;
A method for producing agricultural products, comprising: The method for producing a crop according to claim 1,
In the aqueous solution supply step,
The plasma density time product per unit volume in the second aqueous solution is 6 × 10 ¹¹ sec · cm ⁻³ · ml ⁻¹ or more and 2.4 × 10 ¹⁷ sec · cm ⁻³ · ml ⁻¹ or less. A method for producing crops. In the method for producing agricultural products according to claim 1 or 2,
Having a freezing step of freezing the second aqueous solution;
In the freezing step,
A method for producing an agricultural product, wherein the second aqueous solution is frozen within a range of -196 ° C to 0 ° C. A method for producing a crop, characterized by directly irradiating an atmospheric pressure plasma to a region including a growth point of the crop. The method for producing a crop according to claim 4,
The plasma density time product, which is the product of the plasma density of the atmospheric pressure plasma and the irradiation time,
A method for producing agricultural products, wherein the production method is 6 × 10 ¹⁷ sec · cm ⁻³ or more and 1.2 × 10 ¹⁹ sec · cm ⁻³ or less.

Images