Cultivation management method

Abstract

To provide a technique enabling more appropriate cultivation management of vascular plants for improving the quality of fruits at harvest.SOLUTION: The cultivation management method according to the present invention includes the following steps. Acoustic emission emitted from a vascular plant is detected by an AE sensor (14). An irrigation condition is controlled so that a value obtained by dividing the number of times of acoustic emission detected in a non-irrigation time zone being a time zone in which water is not given in one day by the number of times of acoustic emission detected in the whole day including an irrigation time zone being a time zone in which water is given in one day and the non-irrigation time zone satisfies a predetermined condition.SELECTED DRAWING: Figure 1

Description

[Technical Field]

[0001] The present invention relates to a method for cultivating and managing fruit-bearing vascular plants. [Background technology]

[0002] Patent Document 1 discloses a plant diagnostic device that diagnoses the health of growing vascular plants. This plant diagnostic device includes an AE data generation unit, a rhythm pattern storage unit, and an activity calculation unit. AE stands for acoustic emission. The AE data generation unit detects acoustic emissions generated by cavitation in vascular plants based on the output signal of an AE sensor and generates AE data indicating the detection frequency per sampling time. The rhythm pattern storage unit stores in advance rhythm patterns that indicate the periodic activity rhythms of vascular plants. The activity calculation unit calculates the activity of the vascular plants based on the AE data and the rhythm pattern.

[0003] This plant diagnostic device can calculate the activity level based on AE data that indicates the frequency of acoustic emission detection per sampling time and a rhythm pattern that indicates the periodic activity rhythm of vascular plants. In this way, by focusing on the activity rhythm of healthy vascular plants, it is possible to obtain an index that accurately indicates the health of vascular plant activity, making it possible to accurately and easily diagnose the growth of vascular plants. [Prior art documents] [Patent documents]

[0004] [Patent Document 1] Japanese Patent Application Publication No. 2019-75995 Summary of the Invention [Problem to be solved by the invention]

[0005] As is well known, controlling the amount of irrigation during the cultivation process can improve the quality of fruit, such as sugar content. For example, it is known that the sugar content of tomatoes can be increased by cultivating them with as little irrigation as possible. However, controlling the amount of irrigation is extremely difficult because the plant will wither if the soil moisture is too low, making it difficult to control with an irrigation control system.

[0006] The present invention has been made in view of the circumstances exemplified above, etc. That is, the present invention provides a technique that enables more appropriate cultivation management of vascular plants to improve the quality of fruits at harvest, for example. [Means for solving the problem]

[0007] The method for cultivating and managing a vascular plant (2) bearing fruit (21) according to claim 1 includes the following steps: Detecting acoustic emissions emitted from the vascular plant; The irrigation conditions are controlled so that the value obtained by dividing the number of acoustic emissions detected during the non-irrigation period, which is the period of the day when no water is provided, by the number of acoustic emissions detected throughout the day, including the irrigation period, which is the period of the day when water is provided, and the non-irrigation period, satisfies a predetermined condition.

[0008] In addition, in each section of the application documents, each element may be given a reference symbol in parentheses. However, such reference symbol merely indicates an example of the correspondence between the element and the specific means described in the embodiment described below. Therefore, the present invention is not limited in any way by the above-mentioned reference symbols. [Brief explanation of the drawings]

[0009] [Figure 1] 1 is a block diagram showing a schematic configuration of a system used to implement a cultivation management method according to one embodiment of the present invention. [Figure 2]FIG. 2 is a diagram schematically illustrating a state in which the AE sensor shown in FIG. 1 is attached to a vascular plant. [Figure 3] 10 is a time chart showing the change over time in the acoustic emission count number for high sugar content tomatoes and normal sugar content tomatoes. [Figure 4] 10 is a graph showing the relationship between the night ratio of acoustic emission counts and sugar content. DETAILED DESCRIPTION OF THE INVENTION

[0010] (Embodiment) Hereinafter, exemplary embodiments and specific examples of the present invention will be described with reference to the drawings as appropriate. Note that the following embodiments and their modifications, as well as the descriptions in the drawings related thereto, are schematic or simplified for the purpose of concisely explaining the contents of the present invention, and are not intended to limit the contents of the present invention in any way. Therefore, it goes without saying that the descriptions in the drawings do not necessarily coincide with the actual device configuration. In other words, unless expressly limited by the applicant in the prosecution history of this application, it goes without saying that the present invention should not be interpreted as being limited by the descriptions in the drawings and the device configuration, functions, or operations described below corresponding thereto.

[0011] (Cultivation management system) The cultivation management system 1 shown in Fig. 1 is configured to perform cultivation management of a vascular plant 2 shown in Fig. 2. The vascular plant 2 is cultivated in a cultivation facility, such as a tent or a greenhouse, i.e., in a closed building, and is, for example, a tomato or cherry tomato. The configuration and functions of the cultivation management system 1 according to this embodiment will be described below with reference to Figs. 1 and 2.

[0012] 1, the cultivation management system 1 includes a thermo-hygrometer 11, a pyranometer 12, a moisture meter 13, an AE sensor 14, a processing device 15, a temperature and humidity control unit 16, a solar radiation amount control unit 17, a fertilizer control unit 18, and a moisture amount control unit 19. Of the elements constituting the cultivation management system 1, all except the processing device 15 are located within a cultivation facility for vascular plants 2. The processing device 15 may be located within the cultivation facility or outside the cultivation facility (for example, in a management office, etc.).

[0013] The thermo-hygrometer 11 is provided to measure the temperature and humidity within the cultivation facility and output the measurement results to the arithmetic processing device 15. The pyranometer 12 is provided to measure the amount of light received by the vascular plants 2 within the cultivation facility and output the measurement results to the arithmetic processing device 15. The moisture meter 13 is provided to measure the amount of moisture within the soil in which the vascular plants 2 are planted within the cultivation facility and output the measurement results to the arithmetic processing device 15.

[0014] The AE sensor 14 is configured to detect acoustic emissions emitted from the vascular plants 2 and output the detection results to the processor 15. The AE sensor 14 has a known or well-known configuration, for example, as described in International Publication No. 2010 / 064669 or Japanese Patent Application Laid-Open No. 2015-87214. Specifically, for example, the AE sensor 14 has a configuration as a so-called ultrasonic microphone that detects acoustic emissions by observing ultrasonic waves of 40 to 200 kHz emitted from the vascular plants 2. The manner in which the AE sensor 14 is attached to the vascular plants 2 in this embodiment will be described later.

[0015] The arithmetic processing device 15 is configured to control the operations of the temperature and humidity control unit 16, the solar radiation amount control unit 17, the fertilizer control unit 18, and the moisture amount control unit 19 based on various signals or information acquired through the outputs of the thermo-hygrometer 11, the pyranometer 12, the moisture meter 13, and the AE sensor 14. Specifically, the arithmetic processing device 15 includes a processor formed of a CPU or an MPU, and a storage medium connected to the processor so as to be able to communicate with the processor, and is configured to read and execute computer programs from the storage medium to implement predetermined functions.

[0016] The storage medium includes at least a ROM or a nonvolatile rewritable memory among various non-transient physical storage media such as a ROM or a nonvolatile rewritable memory. The nonvolatile rewritable memory is a storage device, such as a flash memory, that allows information to be rewritten while the power is on but retains the information in an unrewritable manner while the power is off. The storage medium stores the computer program described above as well as various data, such as initial values, maps, and look-up tables, required to execute the program. The storage medium also stores various pieces of information acquired through the outputs of the thermo-hygrometer 11, pyranometer 12, moisture meter 13, and AE sensor 14 in chronological order for a predetermined capacity, i.e., for a predetermined period of time.

[0017] The temperature and humidity control unit 16 controls the temperature and humidity of the air in the cultivation facility for the vascular plants 2. That is, the temperature and humidity control unit 16 is configured as an air conditioner that operates under the control of the arithmetic processing unit 15. The solar radiation control unit 17 controls the amount of solar radiation to the vascular plants 2. Specifically, the solar radiation control unit 17 includes an electric shading curtain, a lighting device that emits light in a predetermined wavelength range, and the like, which operate under the control of the arithmetic processing unit 15.

[0018] The fertilizer control unit 18 is provided to control the supply state of fertilizer to the soil in which the vascular plants 2 are planted within the cultivation facility. That is, the fertilizer control unit 18 is configured as a fertilizer supplying device or a fertilizer spreading device that operates under the control of the arithmetic processing device 15. The water amount control unit 19 is provided to control the amount of water in the soil in which the vascular plants 2 are planted within the cultivation facility. That is, the water amount control unit 19 is configured as an irrigation device that operates under the control of the arithmetic processing device 15.

[0019] (vascular plants) 2, the vascular plant 2 as a subject of cultivation management in this embodiment bears a fruit 21 as the object of cultivation, i.e., the target of harvest. Specifically, in the vascular plant 2, a pedicel 23 branches off from a main stem 22, and the fruit 21 is borne at the tip of a pedicel 24 that further branches off from the pedicel 23. In this embodiment, the vascular plant 2 is configured so that a cluster 25 consisting of multiple fruits 21 grows on one pedicel 23.

[0020] The AE sensor 14 is attached to the stem near the fruit 21. Specifically, in this embodiment, the AE sensor 14 is attached to the main stem 22 at a position corresponding to the vicinity of the position where the fruit stalk 23 having the clusters 25 branches off.

[0021] (Cultivation management method) As is well known, in the cultivation of fruits 21, quality such as sugar content can be improved by controlling the amount of irrigation during the cultivation process. In particular, it is known that the sugar content of tomatoes can be increased by cultivating them with as little irrigation as possible. However, there has been a problem in that it is extremely difficult to control the amount of irrigation because the tomatoes will wither if the soil moisture is too low.

[0022] In this regard, the inventors have discovered that in a vascular plant 2, such as a tomato, the amount of irrigation can be effectively controlled in high sugar content cultivation by focusing on the difference in the occurrence of acoustic emissions in the stem near the fruit 21 between the daytime, i.e., during irrigation hours, and the nighttime, i.e., during non-irrigation hours. This will be explained in more detail below.

[0023] An irrigation period is a period of time during a day when water is supplied. During an irrigation period, a predetermined amount of water (e.g., one drop) is supplied intermittently to the soil at predetermined intervals. In this specification, the process of supplying a predetermined amount of water intermittently to the soil at predetermined intervals is referred to as an irrigation treatment. Therefore, even during an irrigation period, which is a period of time when irrigation treatment is performed, there may be a period of time when the supply of water to the soil is stopped for a short period of time (e.g., in the order of seconds). In contrast, a non-irrigation period is a period of time during a day when water is not supplied, that is, a period of time when irrigation treatment is not performed. During a non-irrigation period, the supply of water to the soil is continuously stopped. In tomato cultivation, the daytime is generally designated as an irrigation period, while the nighttime is designated as a non-irrigation period.

[0024] As is well known, the amount of water absorbed increases as the amount of solar radiation increases. In other words, there is a positive correlation between the amount of solar radiation and the amount of water absorbed. Therefore, in normal cultivation methods that do not impose water stress, irrigation is carried out based on the required amount of water supply calculated from the correlation between the amount of solar radiation and the amount of water absorption. On the other hand, in high-sugar cultivation that imposes water stress, the amount of irrigation is reduced below the required amount of water supply. Specifically, in high-sugar cultivation, the amount of water supplied per water supply (i.e., the number of water droplets) is reduced, the time interval between water supplies is extended, and the irrigation period is shortened compared to normal cultivation methods. These measures can be implemented individually or in combination.

[0025] Acoustic emission occurs within the stem, which absorbs water from the roots for photosynthesis. Photosynthesis is active at the tip of the vascular plant 2. A large amount of photosynthetic products is translocated to the fruit 21 at the tip. In tomatoes, when the fruit 21 is forming, photosynthesis is active in the leaves near the fruit 21. For these reasons, it is important to measure acoustic emission near the fruit 21.

[0026] Figure 3 shows a time chart comparing the acoustic emission generation state between the high-sugar content cultivation method and the normal cultivation method. In Figure 3, the dashed-dotted line indicates the normal cultivation method, and the solid line indicates the high-sugar content cultivation method. The arrows also indicate the daytime, i.e., irrigation times. In the example of Figure 3, the irrigation times are the same (i.e., 9:00 to 16:00) for the high-sugar content cultivation method and the normal cultivation method, but there is a difference in the total amount of irrigation water. As shown in Figure 3, it was found that acoustic emissions are more likely to occur at night, i.e., during non-irrigation times, with the high-sugar content cultivation method. The mechanism behind this is thought to be as follows.

[0027] As is well known, most of the water absorbed by the roots is transpired through the leaves, and carbon dioxide from the atmosphere is taken in through the stomata that open when transpiration occurs, allowing photosynthesis to occur. The amount of water used for photosynthesis is approximately 5% or less of the total amount of water absorbed by the roots. As mentioned above, the amount of water supplied is important for promoting photosynthesis, but if the amount of irrigation is less than the amount calculated from the correlation between the amount of solar radiation and the amount of water absorbed, the vascular plant 2 will absorb as much water as possible into the stem and perform photosynthesis. In this way, even water that is necessary to sustain life will be used for photosynthesis. Therefore, tomatoes grown with a high sugar content will generate acoustic emissions at night, as they attempt to sustain life by absorbing the small amount of water remaining in the soil at night.

[0028] It is assumed that the absolute value of the number of acoustic emissions varies due to the influence of the installation position of the AE sensor 14. Therefore, the evaluation criterion is the ratio of the number of acoustic emissions detected at night to the number of acoustic emissions detected throughout the day, including daytime (i.e., irrigation time periods) and nighttime (i.e., non-irrigation time periods), and this is referred to as the night ratio. The cultivation management method according to this embodiment controls the cultivation conditions, i.e., at least the irrigation conditions, so that the night ratio satisfies predetermined conditions.

[0029] Figure 4 plots the relationship between the night ratio and the sugar content of the actual fruit 21 for the normal cultivation method and the high-sugar content cultivation method. The night ratio on the horizontal axis in Figure 4 is displayed as a percentage [%] obtained by multiplying the divided value by 100. According to this, it is expected that "sweet" tomato fruit 21 with a sugar content of 10 or more can be obtained by controlling the cultivation conditions, i.e., at least the irrigation conditions, so that the night ratio is 30% or more, i.e., 0.3 or more. It is preferable to keep the night ratio below 50%.

[0030] Specifically, for example, the cultivation management method according to this embodiment can be implemented as follows. First, based on data from past cultivation, etc., the allocation of irrigation time periods and non-irrigation time periods and initial values ​​of irrigation conditions for irrigation time periods are determined. The irrigation conditions include, for example, the amount of water supplied per water supply and the time interval between water supplies. Next, using these initial values, the high sugar content cultivation method is implemented for N days, and the time change in the acoustic emission count as shown in FIG. 3 is obtained.

[0031] Then, the night ratio is calculated at the time when the high sugar content cultivation method for N days has been completed (for example, the end of a non-irrigation period), the irrigation conditions are corrected based on the calculation results, and the high sugar content cultivation method for the next N days is carried out under the corrected irrigation conditions. By repeating this process, the irrigation conditions can be feedback-controlled in N-day increments.

[0032] It is preferable that N is 3 to 14. In other words, the value of the night ratio on the horizontal axis in Figure 4 is preferably the average value for 3 days to 2 weeks. This is because if sunny or rainy weather continues for less than 3 days, the value may become abnormal. It is abnormal for the behavior to deviate from the graph in Figure 3 for more than 2 weeks. It is not preferable to leave it for a longer period than this. It is desirable to control the moisture content and return the seedling growth condition to an appropriate state based on the state of the fruit 21.

[0033] In this way, the cultivation management method according to this embodiment detects acoustic emissions emitted from a position on the stem of the vascular plant 2 near the fruit 21, and controls the cultivation conditions, i.e., irrigation conditions, based on the night ratio. This makes it possible to more appropriately manage the cultivation of the vascular plant 2 to improve the quality of the fruit 21 at harvest time.

[0034] (Variation) The present invention is not limited to the above-described embodiments and specific examples. Therefore, the above-described embodiments and the like can be modified as appropriate. Representative modifications will be described below. In the following description of the modifications, differences from the above-described embodiments and the like will be mainly described. Furthermore, the same reference numerals are used for parts that are identical or equivalent to each other in the above-described embodiments and the following modifications. Therefore, in the following description of the modifications, the explanations in the above-described embodiments and the like can be used as appropriate for components that have the same reference numerals as the above-described embodiments and the like, unless there is a technical contradiction or special additional explanation.

[0035] In cultivating a vascular plant 2 with a high sugar content, it is important to control the moisture content of the soil. From this perspective, in the above embodiment, the vascular plant 2 is cultivated in a greenhouse. However, the present invention can also be applied to open-field cultivation, i.e., outdoor cultivation, by taking measures such as covering the field with a mulch sheet.

[0036] 2, the mounting position of the AE sensor 14 is not limited to the main stem 22, but may be, for example, the pedicel 23 or the pedicel 24. Mounting the AE sensor 14 as close as possible to the fruit 21 or cluster 25 increases the sensitivity of the measurement or calculation of the night ratio and eliminates the need to change the mounting position as the seedling grows. There are also no particular limitations on the configuration of the AE sensor 14, and it is possible to use, for example, a pressure sensor or an acceleration sensor.

[0037] The value of N in the above-mentioned N days may be 1 or 2. This allows for fine-tuned control of irrigation conditions while monitoring the night ratio. In this case, various processes such as smoothing filters may be applied to the correction values ​​of irrigation conditions to avoid extreme changes in irrigation control due to abnormal values ​​or control hunting. Therefore, the value of N may be any integer equal to or greater than 1, and is preferably 3 to 14.

[0038] Although the above embodiment has been described using tomatoes as an example, measurement of the acoustic emission frequency can also be used to cultivate vascular plants 2, such as strawberries and peaches, where the sugar content is desired to be increased. As described above, since it is desired to control the water absorption in the soil, it is preferable to cultivate the plants in a greenhouse or tent, where the supply of water to the soil can be managed. Note that, when cultivating outdoors, the amount of water can also be controlled by covering the field with a mulch sheet, for example. Furthermore, night is defined as the time when watering is not being performed. Therefore, the definition of night will differ depending on the season and cultivation method.

[0039] In the control of cultivation conditions based on the night ratio of acoustic emissions, in addition to the control of irrigation conditions, the amount of solar radiation and the amount of fertilizer supply may also be controlled. In this case, the amount of water supply may be corrected according to changes in the amount of solar radiation and the amount of fertilizer supply. In other words, the next irrigation control conditions may be determined based on the current irrigation control conditions, a correction value based on the currently acquired night ratio, a correction value according to the next amount of change in solar radiation, and a correction value according to the next amount of fertilizer supply.

[0040] It goes without saying that the elements constituting the above-described embodiments are not necessarily essential unless they are particularly clearly stated as essential or are considered to be clearly essential in principle. Furthermore, when numerical values ​​such as the number, value, amount, range, etc. of components are mentioned, the present invention is not limited to those specific numbers unless they are particularly clearly stated as essential or are clearly limited to specific numbers in principle. Similarly, when the shape, direction, positional relationship, etc. of components are mentioned, the present invention is not limited to those shapes, directions, positional relationship, etc. unless they are particularly clearly stated as essential or are clearly limited to specific shapes, directions, positional relationship, etc. in principle.

[0041] The modified examples are not limited to the above examples. For example, all or part of one of the multiple specific examples may be combined with all or part of another of the multiple specific examples, provided that there is no technical inconsistency. There is no particular limit to the number of combinations. Similarly, all or part of one of the multiple modified examples may be combined with all or part of another of the multiple modified examples, provided that there is no technical inconsistency. Furthermore, all or part of the above specific example and all or part of the above modified examples may be combined with each other, provided that there is no technical inconsistency. [Explanation of symbols]

[0042] 1. Cultivation management system 11 Thermohygrometer 12 Pyranometer 13 Moisture meter 14 AE sensor 15 Processing Unit 19 Moisture content control unit 2 Vascular plants 21 Fruit 22 Main stem

Claims

1. A method for cultivating and managing a vascular plant (2) that bears fruit (21), comprising: Detecting acoustic emissions emitted from the vascular plant; The irrigation conditions are controlled so that the value obtained by dividing the number of times of the acoustic emissions detected during a non-irrigation time period, which is a time period during which water is not provided, by the number of times of the acoustic emissions detected throughout the day, including the irrigation time period, which is a time period during which water is provided, and the non-irrigation time period, satisfies a predetermined condition. Cultivation management method.

2. The predetermined condition is 0.3 or more. The cultivation management method according to claim 1.

3. The vascular plant is a tomato. The cultivation management method according to claim 1.

4. Cultivating the vascular plant in a cultivation facility. The cultivation management method according to any one of claims 1 to 3.

5. The acoustic emission is detected by observing ultrasonic waves of 40 to 200 kHz emitted from the vascular plant. The cultivation management method according to claim 4.

6. a sensor (14) for detecting the acoustic emission is attached to the stem (22) in the vicinity of the fruit; The cultivation management method according to claim 5.

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