Methods for controlling root rot disease

Abstract

To provide a method for controlling root rot which can be used in any season and can have a high control effect.SOLUTION: A method for controlling root rot includes the step of applying nanobubble water to the soil in which a fruit tree is planted, wherein bubbles included in the nanobubble water contain nitrogen of 80-100 vol.%, and the nanobubble water is applied by direct pouring into the soil.SELECTED DRAWING: None

Description

Technical Field

[0001] The present invention relates to a method for controlling net blotch disease.

Background Art

[0002] Net blotch disease found in fruit trees such as apples, pears, and grapes is caused by the net blotch pathogen. In addition, the net blotch pathogen is a type of filamentous fungus with soil transmissibility, and fruit trees infected with the net blotch pathogen exhibit the characteristic of root rot. Furthermore, it is not easy to observe the diseased parts of net blotch disease, and when symptoms are confirmed in the above-ground part, the fruit trees themselves often die.

[0003] As such a method for controlling net blotch disease, for example, Patent Document 1 discloses "a method for controlling net blotch disease by applying a chemical solution containing 3-chloro-N-(3-chloro-5-trifluoromethyl-2-pyridyl)-α,α,α-trifluoro-2,6-dinitro-p-toluidine using an injector during the growth period of deciduous trees."

Prior Art Documents

Patent Documents

[0004]

Patent Document 1

Summary of the Invention

Problems to be Solved by the Invention

[0005] When the present inventor examined the perfusion treatment of soil using chemical substances such as pesticides described in Patent Document 1 and the like, it was revealed that there are cases where pesticides cannot be administered at an efficient time for controlling the net blotch pathogen in relation to the fruit shipping period.

[0006] Therefore, an object of the present invention is to provide a method for controlling net blotch disease that can be used regardless of the time and can achieve a high control effect.

Means for Solving the Problems

[0007] As a result of intensive studies to achieve the above problems, the present inventors have found that by directly pouring nanobubble water having bubbles containing a predetermined amount of nitrogen into the soil of the orchard soil, a high control effect against the powdery mildew disease can be obtained, and the present invention has been completed. That is, the present inventors have found that the above problems can be achieved by the following configuration.

[0008] [1] A step of applying nanobubble water to the soil in which fruit trees are planted, The bubbles contained in the nanobubble water contain 80 to 100% by volume of nitrogen, A method for controlling powdery mildew disease, wherein the application of the nanobubble water is performed by a method of directly pouring it into the soil of the above soil. [2] The method for controlling powdery mildew disease according to [1], wherein the dissolved oxygen concentration of the nanobubble water is 0.5 to 3.0 mg / L. [3] The method for controlling powdery mildew disease according to [1] or [2], wherein the pouring of the nanobubble water into the soil is a treatment of supplying 50 to 200 L of the nanobubble water per one fruit tree each time. [4] The method for controlling powdery mildew disease according to any one of [1] to [3], wherein the most frequent particle diameter of the bubbles contained in the nanobubble water is 10 to 500 nm. [5] The nanobubble water is 1×10 8 ~1×10 10 The method for controlling powdery mildew disease according to any one of [1] to [4], which has bubbles of / mL. [6] The method for controlling powdery mildew disease according to any one of [1] to [5], wherein the fruit trees are any one of apple, pear and grape.

Effects of the Invention

[0009] According to the present invention, it is possible to provide a method for controlling powdery mildew disease that can be used regardless of the time and can achieve a high control effect.

Brief Description of the Drawings

[0010]

Figure 1

Figure 2

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Figure 5

Mode for Carrying Out the Invention

[0011] Hereinafter, the present invention will be described in detail. The description of the constituent elements described below may be made based on typical embodiments of the present invention, but the present invention is not limited to such embodiments. In this specification, a numerical range represented by "~" means a range including the numerical values described before and after "~" as the lower limit value and the upper limit value.

[0012] The method for controlling root rot of the present invention (hereinafter also abbreviated as "the control method of the present invention") is a control method having a step of applying nanobubble water to the soil in which fruit trees are planted. Further, in the control method of the present invention, the bubbles contained in the nanobubble water contain 80 to 100% by volume of nitrogen, and the application of the nanobubble water is performed by a method of directly pouring it into the soil of the soil. Here, root rot includes violet root rot and white root rot. In addition, the term "purple root rot" refers to a general term for plant diseases caused by Helicobasidium monpa belonging to the genus Hyphomycetes, and the term "white root rot" refers to a general term for plant diseases caused by white root rot fungi belonging to the Ascomycetes (among more than 100 species belonging to the genus Rosellinia, Rosellinia necatrix or Rosellinia compacta). In addition, the term "irrigation" generally refers to the operation of pouring a diluted drug into the soil, but in the control method of the present invention, it refers to the operation of pouring the above-mentioned nano-bubble water into the soil instead of the drug.

[0013] In the present invention, as described above, by applying the nano-bubble water having bubbles containing 80 to 100% by volume of nitrogen directly into the soil of the soil, a high control effect against root rot can be obtained. Although this is not clear in detail, the present inventor speculates as follows. First, it is known that the root rot fungus is an aerobic bacterium and is known to inhabit the region from the ground surface to about 30 cm in the soil. Therefore, in the present invention, by applying the above-mentioned nano-bubble water directly into the soil of the soil, it is presumed that at least a part of the root rot fungus has died or is in a dormant state. Hereinafter, the above-mentioned nano-bubble water and optional components used in the control method of the present invention will be described in detail.

[0014] 〔Nano-bubble water〕 The nano-bubble water used in the control method of the present invention is water containing bubbles having a diameter of less than 1 μm, and the bubbles contain 80 to 100% by volume of nitrogen (hereinafter also abbreviated as "nitrogen NB water"). Here, the diameter (particle size) of the bubbles contained in the nano-bubble water, as well as the most frequent particle size and the number of bubbles described later, are values measured by using the nano-particle tracking analysis method for the Brownian motion migration speed of the bubbles in water. In this specification, the numerical values measured by the nano-particle analysis system NanoSite series (manufactured by NanoSight) are adopted. In the case of the NanoSight series of nanoparticle analysis systems (manufactured by NanoSight), the diameter (particle size) can be measured from the velocity of the Brownian motion of the particles and calculated from that velocity. The most frequent particle size can be confirmed as the mode diameter from the particle size distribution of the existing nanoparticles.

[0015] In the present invention, the nitrogen content in the bubbles of the above-mentioned nanobubble water is preferably 85 to 100% by volume, more preferably 90 to 100% by mass, and even more preferably 95 to 100% by mass, because the control effect against leaf streak disease is further improved.

[0016] In the present invention, the dissolved oxygen concentration of the above-mentioned nanobubble water is preferably 0.5 to 3.0 mg / L, more preferably 1.0 to 2.5 mg / L, and even more preferably 1.5 to 2.0 mg / L, because the control effect against leaf streak disease is further improved. Here, the dissolved oxygen concentration refers to the amount of oxygen dissolved in the above-mentioned nanobubble water under atmospheric pressure, and can be measured with a commercially available oxygen concentration meter.

[0017] In the present invention, the most frequent particle size of the bubbles contained in the above-mentioned nanobubble water is preferably 10 to 500 nm, more preferably 30 to 300 nm, and even more preferably 70 to 130 nm, because the control effect against leaf streak disease is further improved.

[0018] In the present invention, the above-mentioned nanobubble water preferably has 1×10 8 ~1×10 10 bubbles / mL, and particularly, because the balance between the bubble generation time and the bubble persistence is good, it more preferably has more than 1×10 8 bubbles / mL and less than 1×10 10 bubbles / mL, and even more preferably has 5×10 8 ~5×10 9 bubbles / mL.

[0019] Examples of the method for generating the nano-bubble water include, for example, the static mixer method, the Venturi method, the cavitation method, the steam condensation method, the ultrasonic method, the swirling flow method, the pressure dissolution method, and the micropore method. Here, the control method of the present invention may have a generation step of generating the nano-bubble water before applying the nano-bubble water. That is, the control method of the present invention may be, for example, a control method having a generation step of taking water from a water source such as a water storage tank, a well, or agricultural water into a nano-bubble generator to generate nano-bubble water, and an application step of applying the generated nano-bubble water. In addition, as a method of taking water from a water source into a nano-bubble generator, for example, a method of supplying water pumped up from a water source to a nano-bubble generator using a bucket or a pump, and a method of directly feeding water from a flow path laid between the water source and the nano-bubble generator into the nano-bubble generator by connecting the flow path to the nano-bubble generator are exemplified.

[0020] In addition, as the method for generating the nano-bubble water, a generation method using a device that does not intentionally generate radicals is preferable. Specifically, for example, a method of generating using the nano-bubble generator described in paragraphs

[0080] to

[0100] of JP-A-2018-15715 is exemplified. The above content is incorporated herein.

[0021] Examples of other nano-bubble generators that do not intentionally generate radicals include, for example, a liquid ejector that ejects water, a gas mixer that pressurizes and mixes a gas into the water ejected from the liquid ejector, and a micro-bubble generator that generates micro-bubbles in water by passing the water mixed with the gas through the inside thereof. The gas mixer pressurizes and mixes a gas into the liquid flowing toward the micro-bubble generator in a pressurized state between the liquid ejector and the micro-bubble generator. Specifically, a method of generating using the nano-bubble generator shown in FIG. 1 is exemplified. Here, the nanobubble generation device 10 shown in FIG. 1 includes a liquid discharge machine 30, a gas mixing machine 40, and a nanobubble generation nozzle 50 inside thereof. The liquid discharge machine 30 is constituted by a pump, and takes in and discharges raw water for nanobubble water (for example, well water). The gas mixing machine 40 has a container 41 filled with compressed gas and a substantially cylindrical gas mixing machine main body 42, and while flowing the water discharged from the liquid discharge machine 30 into the gas mixing machine main body 42, introduces the compressed gas in the container 41 into the gas mixing machine main body 42. As a result, gas-mixed water is generated in the gas mixing machine main body 42. The nanobubble generation nozzle 50 generates nanobubbles in the gas-mixed water according to the principle of pressure dissolution when the gas-mixed water passes through it. As its structure, the same structure as the nanobubble generation nozzle described in Japanese Patent Application Laid-Open No. 2018-15715 can be adopted. The nanobubble water generated in the nanobubble generation nozzle 50 jets out from the tip of the nanobubble generation nozzle 50, then flows out of the nanobubble generation device 10, and is sent toward a predetermined destination through a flow path (not shown). As described above, in the nanobubble generation device 10, the gas mixing machine 40 mixes compressed gas into the water (raw water) flowing toward the nanobubble generation nozzle 50 in a pressurized state between the liquid discharge machine 30 and the nanobubble generation nozzle 50. Thereby, problems such as cavitation that occur when gas is mixed into water on the suction side (suction side) of the liquid discharge machine 30 can be avoided. Further, since the gas is mixed into the water in a pressurized (compressed) state, the gas can be mixed into the water against the pressure of the water at the gas mixing location. For this reason, it is possible to appropriately mix the gas into the water without generating a negative pressure particularly at the gas mixing location. Furthermore, a water flow path supplied from a water source such as a well or a water supply is connected to the suction side of the liquid ejector 30, and the pressure of the water flowing into the liquid ejector 30 from the upstream side of the liquid ejector 30 in the flow path (i.e., the water pressure on the suction side) is preferably a positive pressure. In this case, the above configuration becomes more meaningful. That is, when the water pressure (suction pressure) on the upstream side of the liquid ejector 30 becomes a positive pressure, gas is mixed into the water on the downstream side of the liquid ejector 30, so that the configuration of the nanobubble generator 10 that can appropriately mix gas into the water even on the downstream side of the liquid ejector 30 becomes more prominent.

[0022] Also, the water used for generating the above nanobubble water is not particularly limited, and for example, rainwater, tap water, well water, agricultural water, distilled water, etc. can be used. Such water may be subjected to other treatments before being used for generating nanobubble water. Examples of other treatments include, for example, pH adjustment, precipitation, filtration, and sterilization. Specifically, for example, when using agricultural water, typically, agricultural water after being subjected to at least one of precipitation and filtration may be used.

[0023] <Any component> The above nanobubble water may contain other components. Examples of the above other components include fertilizers, surfactants, antifreezes, antifoaming agents, preservatives, antioxidants, and thickeners. The types and contents of other components are not particularly limited and can be selected according to the purpose. However, in the present invention, as the above other components, it is preferable that the nanobubble water does not substantially contain radicals. Note that "not substantially containing radicals" does not intend to exclude the inevitable inclusion of radicals due to water used for generating the above nanobubble water (for example, well water containing impurities), but intends to exclude the mixing of radicals generated by any operation.

[0024] 〔Application (Perfusion)〕 In the control method of the present invention, the application of the above-mentioned nano-bubble water is carried out by a method of directly pouring it into the soil of the above-mentioned soil. Here, the direct pouring into the soil is preferably carried out in such a manner that a liquid fertilizer injector (for example, a Pore nozzle manufactured by Nagata Seisakusho Co., Ltd.) is inserted into the soil, and the above-mentioned nano-bubble water is sprayed into the soil at a position about 10 to 30 cm from the ground surface.

[0025] The direct pouring of the above-mentioned nano-bubble water into the soil is preferably a treatment in which 50 to 200 L of the above-mentioned nano-bubble water is supplied per tree of fruit trees at a time, and more preferably a treatment in which 75 to 150 L of the above-mentioned nano-bubble water is supplied per tree of fruit trees at a time, because the control effect of the pink root disease is further improved. Also, the frequency of the direct pouring of the above-mentioned nano-bubble water into the soil is not particularly limited, but from the viewpoint of work efficiency, it is preferably about once a month.

[0026] 〔Fruit trees〕 In the present invention, the fruit trees planted in the soil to which the above-mentioned nano-bubble water is applied are not particularly limited as long as they are fruit trees susceptible to pink root disease. Specific examples of such fruit trees include, for example, apple, pear, grape, loquat, fig, kiwifruit, peach, plum, apricot, Japanese apricot, persimmon, citrus, chestnut, mulberry, tea, cherry, oak, willow, maple, azalea, rhododendron, rose, chrysanthemum, peony, and Chinese peony. Among these, any one of apple, pear, and grape is preferable because the effect of the present invention becomes apparent.

Examples

[0027] Hereinafter, the present invention will be described in more detail with reference to examples. The materials, amounts used, ratios, treatment contents, treatment procedures, etc. shown in the following examples can be appropriately changed without departing from the spirit of the present invention. Therefore, the scope of the present invention should not be construed as being limited by the examples shown below.

[0028] [Example 1] In Example 1, it was carried out on Japanese pears (cultivar: Kohsui) cultivated in Shirai City, Chiba Prefecture from April 2020 to October 2020. Specifically, for the soil in which a Japanese pear tree (one tree) that was judged to postpone fruit set considering the influence of root rot in April 2020 was planted, the nitrogen NB water generated by the method described below was directly injected into the soil (depth 30 cm) under the following irrigation conditions. <Irrigation conditions> · Water volume: 100 L / time · Frequency: 1 time / month · Equipment used: Liquid fertilizer injector (pore nozzle, manufactured by Nagata Seisakusho Co., Ltd.)

[0029] <Method for generating nitrogen NB water> Nitrogen NB water was generated by generating bubbles (nanobubbles) in water by a pressurized dissolution method using a nanobubble generator [manufactured by Kakui Manufacturing Co., Ltd., Aquasolution Business Division (currently Aquasolution Co., Ltd.), 100V, 10L / min type]. Note that well water (dissolved oxygen concentration: 6.0 mg / L) was used for the water used to generate the nanobubble water, and nitrogen (industrial nitrogen, concentration: 99.9% by volume) was used for the gas constituting the bubbles. In addition, the conditions for generating nanobubbles using the above nanobubble generator were carried out under the conditions where the analysis results by a nanoparticle analysis system NanoSite LM10 (manufactured by NanoSight) were as follows. · Number of bubbles per 1 mL of water: 5×10 8 pieces / mL · Most frequent particle diameter of bubbles: 100 nm · Dissolved oxygen concentration: 1.5 - 2.0 mg / L

[0030] <Evaluation of the control effect of root rot> The fruits of Japanese pears were harvested in August 2020. Note that the above irrigation was carried out until October 2020 after the harvest. As a result, it was confirmed that fruits that were hypertrophied to an equal or greater extent and new shoots that had grown were obtained even when compared with healthy trees that were cultivated during the same period and not affected by Rosellinia root rot. Since no pesticides were used in the perfusion treatment, no residual pesticides were detected in the obtained fruits. In addition, it was confirmed that the color of the leaves and the tree vigor had recovered to the same extent as those of healthy trees. From the above, it was determined that the Rosellinia root rot of the trees used in Example 1 was controlled.

[0031] [Example 2] In Example 2, it was carried out targeting Japanese pears (cultivar: Kohsui) cultivated in Shirai City, Chiba Prefecture from October 2020 to October 2021. Specifically, Japanese pear trees (Figure 2) that were determined to defer fruiting in consideration of the influence of Rosellinia root rot as of October 2020 were used, and perfusion was carried out under the same conditions as in Example 1 except that "BIB (BAG IN BOX) [880K tender (MW-10NH-K00-A) IS 1907, manufactured by Okura Industries Co., Ltd.]" described below was used as nitrogen NB water. When compared with healthy trees (Figure 3) existing next to the trees shown in Figure 2, it can be seen that the trees shown in Figure 2 have fewer new shoots growing upward due to the influence of Rosellinia root rot. <BIB (BAG IN BOX)> · Number of bubbles per 1 mL of water: 5×10 8 individuals / mL · Most frequent particle size of bubbles: 100 nm · Dissolved oxygen concentration: 1.5 - 2.0 mg / L

[0032] <Evaluation of the control effect of Rosellinia root rot> Japanese pear fruits were harvested in August 2021. Figure 4 shows the trees at the harvesting stage of the trees shown in Figure 2. The above-described perfusion was carried out until October 2021 after harvesting. As a result, it was confirmed that fruits that were hypertrophied to an equal or greater extent and new shoots that had grown were obtained even when compared with healthy trees (Figure 5) that were cultivated during the same period and not affected by Rosellinia root rot. Since no pesticides were used in the perfusion treatment, no residual pesticides were detected in the obtained fruits. In addition, it was confirmed that the color of the leaves and the tree vigor had recovered to the same extent as that of healthy trees. From the above, it was determined that the root rot of the trees used in Example 2 was controlled.

[0033] [Comparative Example 1] In Comparative Example 1, it was carried out on Japanese pears (cultivar: Kohsui) cultivated in Shirai City, Chiba Prefecture since October 2020. Specifically, one Japanese pear tree that was judged to defer fruiting considering the influence of root rot in October 2020 was used. Also, perfusion was carried out under the same conditions as in Example 1, except that well water (dissolved oxygen concentration: 6.0 mg / L) was used to dilute the pesticide (Fronside) instead of nitrogen NB water. In Comparative Example 1, perfusion was carried out until March 2021. However, since no recovery was observed in the leaf color and tree vigor, the flowers were removed and fruiting was deferred.

Explanation of Signs

[0034] 10 Nanobubble generator 30 Liquid discharger 40 Gas mixer 41 Container 42 Gas mixer main body 50 Nanobubble generation nozzle

Claims

1. The method includes a step of applying nanobubble water to soil in which fruit trees are planted, The bubbles contained in the nanobubble water contain 80 to 100% by volume of nitrogen, The method for controlling root rot, wherein the nanobubble water is applied by directly irrigating the soil.

2. The method for controlling root rot according to claim 1, wherein the dissolved oxygen concentration of the nanobubble water is 0.5 to 3.0 mg / L.

3. The method for controlling root rot disease according to claim 1 or 2, wherein the irrigation of the soil with the nanobubble water is a treatment in which 50 to 200 L of the nanobubble water is supplied per one fruit tree.

4. The method for controlling root rot disease according to any one of claims 1 to 3, wherein the most frequent particle diameter of bubbles contained in the nanobubble water is 10 to 500 nm.

5. The nanobubble water is 1×10 ８ ~1×10 １０ The method for controlling root rot disease according to any one of claims 1 to 4, wherein the composition has bubbles of 10 bubbles / mL.

6. The method for controlling root rot disease according to any one of claims 1 to 5, wherein the fruit tree is any one of apple, pear and grape.

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