Seedling raising methods

Abstract

To provide a seedling-raising method that makes it possible to suppress the decline in the yield of seedlings while reducing the cost required to grow seedlings.SOLUTION: A seedling-raising method comprises: raising a seedling T by artificial light for a predetermined period; and based on the external environment over a given period of time, selecting a greenhouse seedling-raising period during which a seedlings T is raised in a greenhouse 12 using natural light SR, an outdoor seedling-raising period during which a seedling is raised outdoors, and a seedling-raising pattern in which the order of greenhouse seedling-raising and outdoor seedling-raising is determined, and raising the seedling T raised by artificial light according to the seedling-raising pattern.SELECTED DRAWING: Figure 1

Description

[Technical Field]

[0001] This invention relates to a method for raising seedlings. [Background technology]

[0002] One example of a seedling cultivation method involves growing seedlings suitable for planting in open fields over a period of 6 to 12 months. However, in open-field cultivation, seedling growth is affected by weather and pests, which tends to reduce the seedling yield. In particular, seedlings are prone to dying during the early seedling stage, which occurs 2 or 3 months after seed germination, thus reducing the seedling yield. Therefore, a method has been proposed for growing mountain-ready seedlings in a facility where day length can be controlled using artificial light (see, for example, Patent Document 1). [Prior art documents] [Patent Documents]

[0003] [Patent Document 1] Japanese Patent Publication No. 2019-68768 [Overview of the project] [Problems that the invention aims to solve]

[0004] By growing seedlings in facilities where day length can be controlled using artificial light, it is possible to reduce the rate of seedling death during the early stages, thereby suppressing the decline in seedling yield. However, growing seedlings under artificial light from seed germination to planting size increases the cost required for raising each seedling sent to the mountains. [Means for solving the problem]

[0005] A seedling cultivation method for solving the above problems includes growing seedlings with artificial light for a predetermined period, and selecting a seedling cultivation pattern that defines a period of greenhouse cultivation in a greenhouse using natural light, a period of outdoor cultivation outdoors, and the order of the greenhouse cultivation and the outdoor cultivation, based on the external environment during the predetermined period, and cultivating the seedlings grown with artificial light according to the seedling cultivation pattern. [Effects of the Invention]

[0006] According to the present invention, it is possible to reduce the costs required to grow seedlings while suppressing the decline in seedling yield. [Brief explanation of the drawing]

[0007] [Figure 1] This is a schematic diagram illustrating seedling cultivation methods, including cultivation under artificial light, greenhouse cultivation, and outdoor cultivation. [Figure 2] This is a block diagram showing the structure of a seedling cultivation system. [Figure 3] This is a Gantt chart showing an example of a seedling cultivation pattern. [Modes for carrying out the invention]

[0008] An embodiment of the seedling cultivation method will be described with reference to Figures 1 to 3. [Seedling raising method] The seedling cultivation method of this disclosure includes growing seedlings with artificial light over a predetermined period, and cultivating seedlings grown with artificial light according to a seedling cultivation pattern. The seedling cultivation pattern defines the period of greenhouse cultivation, the period of outdoor cultivation, and the sequence between greenhouse cultivation and outdoor cultivation. The seedling cultivation pattern is selected based on the external environment during the predetermined period in which the seedlings are grown with artificial light.

[0009] This seedling cultivation method involves growing seedlings under artificial light, followed by cultivation in a pattern that includes at least one of outdoor or greenhouse cultivation. This reduces the cost required to cultivate seedlings compared to cultivation using artificial light alone. Furthermore, the external environment during seedling cultivation is used to select the cultivation pattern, ensuring that an environment suitable for cultivating seedlings already grown under artificial light is selected, thereby minimizing the decline in seedling yield. The seedling cultivation method will be explained in detail below with reference to Figure 1.

[0010] Figure 1 schematically shows the seedling growing environment in which seedlings are grown in the seedling growing method of this disclosure. As shown in Figure 1, seedlings T, which are the target of seedling cultivation by the seedling cultivation method, are first grown for a predetermined period of time in a seedling cultivation facility 11 where seedlings T are grown under artificial light. The period during which seedlings T are grown in the seedling cultivation facility 11 may be several months, for example, two months or less. Seedlings T are grown in the seedling cultivation facility 11 from the germination stage until they reach a predetermined seedling length or longer.

[0011] The seedling nursery facility 11 comprises a storage section 11A and an illumination section 11B. The storage section 11A defines a seedling nursery space capable of accommodating multiple seedlings T. The storage section 11A is configured to block natural light. The illumination section 11B is configured to irradiate the seedling nursery space with artificial light. The illumination section 11B may be various types of light sources. The light sources may be, for example, fluorescent lamps, high-pressure sodium lamps, and light-emitting diodes (LEDs).

[0012] In the seedling facility 11, the irradiation unit 11B controls the day length and the light intensity within the containment unit 11A. Day length is the amount of time that light is irradiated per day. Day length is set to a predetermined length that falls within the range of, for example, 12 hours or more and 20 hours or less. Light intensity is set to a predetermined photon flux density (PFD). Photon flux density is, for example, 100 μmol m -2 s -1 The above is 500 μmolm-2 s -1 It is set to a predetermined intensity within the following range.

[0013] The seedling raising facility 11 may be configured to be able to set the temperature, humidity, and carbon dioxide concentration in the accommodation part 11A to predetermined values. That is, the seedling raising facility 11 may be configured to be able to control one or more of the temperature, humidity, and carbon dioxide concentration in the accommodation part 11A. The seedling raising facility 11 may include an imaging unit configured to be able to image the seedlings T located in the accommodation part 11A. The imaging unit may be various imaging elements capable of generating an image of the seedlings T.

[0014] In addition, it is preferable that the cultivation until the seedlings T reach the sprouting state is also performed in an environment equivalent to that of the seedling raising facility 11. That is, it is preferable that the processes from sowing, germination, and transplanting of the germinated sprouts are performed under artificial light.

[0015] The seedling raising method of the present disclosure includes at least one of greenhouse seedling raising and outdoor seedling raising. That is, the seedling raising method may include only greenhouse seedling raising, may include only outdoor seedling raising, or may include both greenhouse seedling raising and outdoor seedling raising. When the seedling raising method includes greenhouse seedling raising and outdoor seedling raising, the greenhouse seedling raising may be performed before the outdoor seedling raising, or the outdoor seedling raising may be performed before the greenhouse seedling raising. When the seedling raising method includes greenhouse seedling raising and outdoor seedling raising, at least one of the greenhouse seedling raising and the outdoor seedling raising may be included multiple times. That is, the seedling raising method may include only greenhouse seedling raising multiple times, may include only outdoor seedling raising multiple times, or may include both greenhouse seedling raising and outdoor seedling raising multiple times. When the seedling raising method includes at least one of greenhouse seedling raising and outdoor seedling raising multiple times, the greenhouse seedling raising and the outdoor seedling raising are performed alternately.

[0016] In greenhouse seedling raising, the seedlings T after being grown in the seedling raising facility 11 are grown in the greenhouse 12. The greenhouse 12 includes a storage part 12A and a light shielding part 12B. The storage part 12A defines a greenhouse space capable of accommodating a plurality of seedlings T. The storage part 12A is configured to be able to transmit natural light SR. The storage part 12A is configured to be able to transmit, for example, light in the entire wavelength range included in the natural light SR. The storage part 12A may be, for example, a vinyl house. The light shielding part 12B is configured to be able to block at least a part of the natural light SR incident into the storage part 12A. The light shielding part 12B may be configured to be able to set the ratio of the blocked natural light SR to an arbitrary value, for example.

[0017] In greenhouse seedling raising, the seedlings T are grown in terms of the day length depending on the natural light SR, the temperature depending on the natural light SR, the humidity depending on the outside air, and the carbon dioxide concentration depending on the outside air. Note that at the same time, the temperature inside the greenhouse 12 is higher than the outside air temperature in the field 13.

[0018] In outdoor seedling raising, the seedlings T after being grown in the seedling raising facility 11 are grown in the field 13. In outdoor seedling raising, the seedlings T are exposed to the natural light SR and the outside air. In outdoor seedling raising, the seedlings T are grown in terms of the day length, temperature, humidity, and carbon dioxide concentration in the field 13.

[0019] The above-mentioned seedling raising facility 11, greenhouse 12, and field 13 may be arranged adjacent to each other, for example, within a site having a predetermined size. Between the seedling raising facility 11 and the greenhouse 12, between the greenhouse 12 and the field 13, and between the field 13 and the seedling raising facility 11, a transport part configured to be able to transport the seedlings T may be located respectively.

[0020] In each of the seedling facility 11, greenhouse 12, and field 13, multiple lots of seedlings T may be grown simultaneously. Each lot is a group of seedlings T sown at the same time. Each lot is associated with identification information to distinguish it from other lots. The identification information may be, for example, an identification number, a name, and at least one of the month and day of sowing. That is, the identification information may be any one of the identification number, name, and month and day of sowing, or it may include any two or more of these.

[0021] In the seedling cultivation method of this disclosure, a seedling cultivation pattern is selected based on the external environment during a predetermined period in which seedlings T grow in the seedling cultivation facility 11. The external environment during the predetermined period used to select the seedling cultivation pattern may be the external environment at the start of the predetermined period, the external environment at the end of the predetermined period, or the external environment during the predetermined period. Alternatively, the external environment during the predetermined period may be the average value of the external environment during the predetermined period, or a representative value of the external environment during the predetermined period. The representative value may be, for example, the minimum value, the maximum value, or the mode.

[0022] The external environment may include at least one of the following: date, ambient temperature, frost occurrence, and solar radiation. That is, the external environment may consist of only one of the following: date, ambient temperature, frost occurrence, and solar radiation, or it may consist of two or more selected from the following: date, ambient temperature, frost occurrence, and solar radiation. This improves the accuracy of estimating the external environment when growing seedlings T that have been grown under artificial light, and thus improves the accuracy of selecting seedling cultivation patterns.

[0023] The tree species to which the seedling cultivation method is applied may be conifers or broad-leaved trees. Examples of conifers may include Japanese cedar, cypress, pine, fir, larch, and Sakhalin fir. Examples of broad-leaved trees may include sawtooth oak, Japanese oak, cherry, zelkova, and beech.

[0024] [Seedling cultivation system] The seedling cultivation system will be explained with reference to Figure 2. As shown in Figure 2, the seedling cultivation system 20 comprises a control unit 21, a storage unit 22, and a notification unit 23. One example of the seedling cultivation system 20 is embodied by a computer corresponding to the control unit 21 and the storage unit 22, and a display corresponding to the notification unit 23. Alternatively, another example of the seedling cultivation system 20 is embodied by a computer corresponding to the control unit 21, a server corresponding to the storage unit 22, and a display corresponding to the notification unit 23.

[0025] The memory unit 22 stores multiple seedling cultivation patterns. Each seedling cultivation pattern is associated with external environmental conditions that should be used to select that pattern. The external environment may be, for example, the date, ambient temperature, frost occurrence, and solar radiation during a predetermined period in which the seedlings T are being cultivated under artificial light. In other words, the external environment may consist of just one of the date, ambient temperature, frost occurrence, and solar radiation, or it may include any two or more of these.

[0026] The memory unit 22 stores information regarding the growth status of the seedling T. This information may include, for example, at least one of the following: seedling length, root diameter, and branch length. In other words, the information regarding the growth status of the seedling T may include any one of the following: seedling length, root diameter, and branch length, or any two or more of these. The memory unit 22 stores the growth status that the seedling T should meet at the end of artificial light cultivation.

[0027] The control unit 21 receives external input of identification information for each lot, images of one or more seedlings T included in each lot, and the external environment used to select the seedling cultivation pattern. The input of identification information for each lot, images of seedlings T, and the external environment to the control unit 21 may be performed by the administrator of the seedling cultivation system 20.

[0028] Alternatively, an identification information acquisition unit that acquires identification information for each lot, an imaging unit that captures images of seedlings T, and an external environment acquisition unit that acquires the external environment may input various information to the control unit 21 via a predetermined network. In this case, the seedling facility 11 is equipped with an identification information acquisition unit and an external environment acquisition unit. The identification information acquisition unit may be, for example, an imaging unit configured to capture identification information attached to each lot, or an input unit configured to allow the administrator of the seedling system 20 to input identification information. The external environment acquisition unit may be, for example, various sensors configured to acquire the external environment, or an input unit configured to allow the administrator of the seedling system 20 to input the external environment.

[0029] The control unit 21 outputs information corresponding to the seedling cultivation pattern selected by the control unit 21 to the notification unit 23. The information corresponding to the seedling cultivation pattern includes, for example, information on the treatment to be performed on the seedling T and information on the timing of the treatment to be performed on the seedling T. Both the information on the treatment to be performed on the seedling T and the information on the timing of the treatment are linked to a specific lot.

[0030] The control unit 21 selects a seedling cultivation pattern from a plurality of seedling cultivation patterns stored in the storage unit 22 to grow seedlings T of each lot, based on the input external environment. The control unit 21 grasps the growth status of seedlings T from the input image of seedlings T. The control unit 21 compares the growth status of seedlings T with the information on the growth status of seedlings T stored in the storage unit 22. For example, if the control unit 21 determines that the growth status of seedlings T does not meet the growth status stored in the storage unit 22 at the end of a predetermined period, it may extend the seedling cultivation period under artificial light. Alternatively, if the control unit 21 determines that the growth status of seedlings T meets the growth status stored in the storage unit 22 during a predetermined period, it may shorten the seedling cultivation period under artificial light.

[0031] Thus, the predetermined period of growth under artificial light may be changed based on the growth state of the seedling T under artificial light. This prevents the seedling T from being grown under artificial light even after its growth state has exceeded the target growth state, thus preventing the cost of growing the seedling T from increasing compared to when the period of growing the seedling T under artificial light is fixed to a specific period. Furthermore, since it prevents the termination of growth under artificial light even if the growth state of the seedling T has not reached the target growth state, it is possible to increase the survival rate of the seedling T after artificial light cultivation compared to when the period of growing the seedling T under artificial light is fixed to a specific period.

[0032] The notification unit 23 provides notifications in accordance with the information input from the control unit 21. For example, the notification unit 23 notifies the processing that should be performed on a particular lot of seedlings. The processing that should be performed on a group of seedlings may include, for example, transferring the seedlings from the nursery facility 11 to the greenhouse 12, transferring the seedlings from the nursery facility 11 to the field 13, transferring the seedlings from the greenhouse 12 to the field 13, and transferring the seedlings from the field 13 to the greenhouse 12. The notification unit 23 may also provide advance notifications of the processing that should be performed on a particular lot of seedlings. For example, the notification unit 23 may notify the number of days in advance when the processing that should be performed on a particular lot of seedlings should be performed.

[0033] [Seedling cultivation pattern] An example of a seedling cultivation pattern is explained with reference to Figure 3. Figure 3 shows an example of a seedling cultivation pattern when the tree species of seedling T grown by the cultivation method is larch. The seedling cultivation pattern includes six patterns, from the 1st seedling cultivation pattern to the 6th seedling cultivation pattern.

[0034] As shown in Figure 3, if the tree species of seedling T is larch, the outside temperature from early October to mid-April is unsuitable for larch growth, making outdoor seedling cultivation in field 13 impossible during this period. However, even during periods when outdoor seedling cultivation is impossible, outdoor seedling cultivation in field 13 is possible from April onward by performing acclimatization treatment on seedling T after the completion of cultivation under artificial light.

[0035] Furthermore, if the tree species of seedling T is larch, two planting periods are set for planting in forest areas: the first planting period from early March to mid-July, and the second planting period from early September to late November. Also, if the tree species of seedling T is larch, two shipping periods are set: the first shipping period from early April to late May, and the second shipping period from early October to late November. Note that each shipping period may be extended by about one week before or after the two-month period mentioned above.

[0036] In the first seedling cultivation pattern, seedlings T are grown from early August to late March. Seedlings T sown in early July and whose germination and transplanting processes are completed within July are subject to the first seedling cultivation pattern. The first seedling cultivation pattern is one in which greenhouse cultivation is continued from the start of seedling cultivation according to the seedling cultivation pattern until the shipment of seedlings T. According to the first seedling cultivation pattern, even in seasons when it is difficult to grow seedlings T outdoors, it is possible to cultivate seedlings T by selecting the first seedling cultivation pattern, which continues greenhouse cultivation.

[0037] In the first seedling cultivation pattern, seedlings are grown in the seedling facility 11 from sowing to transplanting, and then under artificial light cultivation after transplanting. The period for cultivation under artificial light is set to two months, from early August to late September. The temperature is set to 22°C and the PFD is 110 μmolm in the containment section 11A of the seedling facility 11. -2 s -1 The settings are configured such that the day length is set to 18 hours. In the first seedling cultivation pattern, greenhouse cultivation takes place after seedling cultivation under artificial light is completed. As a result, in the first seedling cultivation pattern, greenhouse cultivation takes place for six months, from early October to late March. Seedlings T grown under the first seedling cultivation pattern are shipped during the first shipping period.

[0038] In the first seedling cultivation pattern, before transitioning from artificial light cultivation to greenhouse cultivation, an acclimatization treatment is performed to adapt the seedlings T to the greenhouse environment. In the acclimatization treatment, the environmental conditions within the containment section 11A are changed to the day length and temperature of early October when greenhouse cultivation begins. The acclimatization treatment is set to, for example, one to two weeks, including the end of the artificial light cultivation period. Furthermore, if seedlings T are cultivated using the first seedling cultivation pattern, it is preferable to move the seedlings T to the field 13 and leave them in the field 13 for a predetermined period after cultivation using the seedling cultivation pattern and before shipping the seedlings T. This allows for acclimatization treatment to adapt the seedlings T to the outdoor environment.

[0039] In the second seedling cultivation pattern, seedling T is grown from early October to late March. Seedling T that was sown in early September and whose germination and transplanting processes were completed within September is subject to the second seedling cultivation pattern. Similar to the first seedling cultivation pattern, greenhouse cultivation continues in the second seedling cultivation pattern from the start of cultivation under the seedling cultivation pattern until the shipment of seedling T.

[0040] In the second seedling cultivation pattern, seedlings are grown in the seedling facility 11 from sowing to transplanting, and then under artificial light cultivation after transplanting. The period for cultivation under artificial light is set to two months, from early October to late November. The temperature is set to 22°C and the PFD is 110 μmolm in the containment section 11A of the seedling facility 11. -2 s -1 The settings are configured such that the day length is set to 18 hours. In the second seedling cultivation pattern, greenhouse cultivation takes place after seedling cultivation under artificial light is completed. As a result, in the second seedling cultivation pattern, greenhouse cultivation takes place over a period of four months, from early December to late March. Seedlings T grown under the second seedling cultivation pattern are shipped during the first shipping period.

[0041] Thus, the seedling cultivation pattern includes a first seedling cultivation pattern in which greenhouse cultivation is continued for a first period from the start of seedling cultivation according to the seedling cultivation pattern until the shipment of seedling T, and a second seedling cultivation pattern in which greenhouse cultivation is continued for a second period shorter than the first period from the start of seedling cultivation according to the seedling cultivation pattern until the shipment of seedling T. Therefore, according to the seedling cultivation method of this embodiment, it is possible to select either the first seedling cultivation pattern or the second seedling cultivation pattern, and thus it is possible to set the period of greenhouse cultivation to a length suitable for the time when seedling growth under artificial light begins.

[0042] In the second seedling cultivation pattern, before transitioning from artificial light cultivation to greenhouse cultivation, an acclimatization treatment is performed to adapt the seedlings T to the greenhouse environment. In the acclimatization treatment, the environmental conditions within the containment section 11A are changed to the day length and temperature of early December when greenhouse cultivation begins. The acclimatization treatment is set to, for example, one to two weeks, including the end of the artificial light cultivation period. Furthermore, if seedlings T are cultivated using the second seedling cultivation pattern, it is preferable to move the seedlings T to the field 13 and leave them in the field 13 for a predetermined period after cultivation using the seedling cultivation pattern and before shipping the seedlings T. This makes it possible to perform an acclimatization treatment to adapt the seedlings T to the outdoor environment.

[0043] In the third seedling cultivation pattern, seedlings T are grown from early December to late May. Seedlings T sown in early November and whose germination and transplanting processes are completed within November are subject to the third seedling cultivation pattern. The third seedling cultivation pattern involves continuing greenhouse cultivation for the first period, followed by continuing outdoor cultivation for the second period. Since multiple seedling cultivation patterns include the third seedling cultivation pattern, greenhouse cultivation is carried out when it is difficult to grow seedlings outdoors, while outdoor cultivation is carried out when it is possible to grow seedlings T outdoors. Therefore, for part of the seedling cultivation period, it is possible to grow seedlings T by utilizing the sunlight and temperature available outdoors.

[0044] In the third seedling raising pattern, the growth during the period from sowing to transplanting and the seedling raising by artificial light after transplanting are carried out in the seedling raising facility 11. The period of seedling raising by artificial light is set to two months from early December to late January. In the accommodation part 11A of the seedling raising facility 11, the temperature is set to 22 °C, the PFD is set to 110 μmolm -2 s -1 and the day length is set to 18 hours. In the third seedling raising pattern, after the seedling raising by artificial light is completed, greenhouse seedling raising is carried out, and then outdoor seedling raising is carried out. Thus, in the third seedling raising pattern, greenhouse seedling raising is carried out for two and a half months from early February to mid-April, and outdoor seedling raising is carried out for one and a half months from mid-April to late May. The seedlings T grown by the third seedling raising pattern are shipped during the first shipping period.

[0045] In the third seedling raising pattern, in the seedling raising by artificial light, before shifting from the seedling raising by artificial light to greenhouse seedling raising, an acclimation treatment is performed to apply the seedlings T to the environment in greenhouse seedling raising. In the acclimation treatment, the conditions in the environment in the accommodation part 11A are changed to the day length and temperature in early February when the greenhouse seedling raising starts. The acclimation treatment is set, for example, to one week or more and two weeks or less including the end of the seedling raising period by artificial light.

[0046] In the fourth seedling raising pattern, the seedlings T are grown from early February to late September. The fourth seedling raising pattern is applied to the seedlings T sown in early January and for which the processes from germination to transplanting are completed in January. Similar to the third seedling raising pattern, the fourth seedling raising pattern is a pattern in which greenhouse seedling raising is continued for the first period and then outdoor seedling raising is continued for the second period.

[0047] In the fourth seedling raising pattern, the growth from sowing to transplanting and the seedling raising by artificial light after transplanting are carried out in the seedling raising facility 11. The period of seedling raising by artificial light is set to two months from early February to late March. In the accommodation part 11A of the seedling raising facility 11, the temperature is set to 22 °C, the PFD is set to 110 μmolm -2 s -1The settings are configured such that the day length is set to 18 hours. In the fourth seedling cultivation pattern, after seedling cultivation under artificial light is completed, greenhouse cultivation takes place, followed by outdoor cultivation. Thus, in the fourth seedling cultivation pattern, greenhouse cultivation takes place for one week in early April, and outdoor cultivation takes place for approximately six months from early April to late September. Seedlings T grown under the fourth seedling cultivation pattern are shipped during the second shipping period.

[0048] In the fourth seedling cultivation pattern, before transitioning from artificial light cultivation to greenhouse cultivation, an acclimatization treatment is performed to adapt the seedlings T to the greenhouse environment. In the acclimatization treatment, the environmental conditions within the containment section 11A are changed to the day length and temperature of early April when greenhouse cultivation begins. The acclimatization treatment is set to last for at least one week and no more than two weeks, including the end of the artificial light cultivation period.

[0049] In the fifth seedling cultivation pattern, seedlings T are grown from early April to late September. Seedlings T that were sown in early March and whose germination and transplanting processes were completed within March are subject to the fifth seedling cultivation pattern. Similar to the third seedling cultivation pattern, the fifth seedling cultivation pattern involves continuing greenhouse cultivation for the first period, followed by continuing outdoor cultivation for the second period.

[0050] In the fifth seedling cultivation pattern, seedlings are grown from sowing to transplanting, and then under artificial light cultivation after transplanting, all within the seedling cultivation facility 11. The period for artificial light cultivation is set to two months, from early April to late May. Within the containment section 11A of the seedling cultivation facility 11, the temperature is set to 22°C and the PFD is 110 μmolm -2 s -1 The settings are configured such that the day length is set to 18 hours. In the fifth seedling cultivation pattern, after seedling cultivation under artificial light is completed, greenhouse cultivation is carried out, followed by outdoor cultivation. Thus, in the fifth seedling cultivation pattern, greenhouse cultivation takes place for one week in early June, and outdoor cultivation takes place for approximately four months from early June to late September. Seedlings T grown under the fourth seedling cultivation pattern are shipped during the second shipping period.

[0051] In the fifth seedling cultivation pattern, before transitioning from artificial light cultivation to greenhouse cultivation, an acclimatization treatment is performed to adapt the seedlings T to the greenhouse environment. In the acclimatization treatment, the environmental conditions within the containment section 11A are changed to the day length and temperature of early June when greenhouse cultivation begins. The acclimatization treatment is set to last for at least one week and no more than two weeks, including the end of the artificial light cultivation period.

[0052] In the sixth seedling cultivation pattern, seedlings T are grown from early June to late November. Seedlings T that were sown in early May and whose germination and transplanting processes were completed within May are subject to the sixth seedling cultivation pattern. Similar to the first seedling cultivation pattern, the sixth seedling cultivation pattern is one in which greenhouse cultivation is continued from the start of seedling cultivation according to the seedling cultivation pattern until the shipment of seedlings T.

[0053] In the sixth seedling cultivation pattern, seedlings are grown from sowing to transplanting, and then under artificial light cultivation after transplanting, all within the seedling cultivation facility 11. The period for artificial light cultivation is set to two months, from early June to late July. Within the containment section 11A of the seedling cultivation facility 11, the temperature is set to 22°C and the PFD is 110 μmolm -2 s -1 The settings are configured such that the day length is set to 18 hours. In the sixth seedling cultivation pattern, greenhouse cultivation takes place after artificial light cultivation is completed. As a result, in the sixth seedling cultivation pattern, greenhouse cultivation takes place over a period of four months, from early August to late November. Seedlings T grown using the sixth seedling cultivation pattern are shipped during the second shipping period.

[0054] In the sixth seedling cultivation pattern, before transitioning from artificial light cultivation to greenhouse cultivation, an acclimatization treatment is performed to adapt the seedlings T to the greenhouse environment. In the acclimatization treatment, the environmental conditions within the containment section 11A are changed to the day length and temperature of early August when greenhouse cultivation begins. The acclimatization treatment is set to, for example, one to two weeks, including the end of the artificial light cultivation period. In the sixth seedling cultivation pattern, the seedlings T are grown so that they have winter buds.

[0055] Furthermore, the sixth seedling cultivation pattern may be modified as follows: The sixth seedling cultivation pattern may be a pattern in which outdoor cultivation is continued from the start of seedling cultivation according to the seedling cultivation pattern until the shipment of seedling T. In other words, in the sixth seedling cultivation pattern, outdoor cultivation may be carried out after seedling cultivation under artificial light is completed. In this case, outdoor cultivation will be carried out for four months from early August to late November.

[0056] In the sixth seedling cultivation pattern, before transitioning from artificial light cultivation to outdoor cultivation, an acclimatization treatment is performed to adapt the seedlings T to the outdoor cultivation environment. In the acclimatization treatment, the environmental conditions within the containment section 11A are changed to the day length and temperature of early August when outdoor cultivation begins. The acclimatization treatment is set to, for example, one to two weeks, including the end of the artificial light cultivation period. This allows the seedlings T to grow so that they have winter buds.

[0057] As described above, the control unit 21 selects a seedling cultivation pattern for growing seedlings T of each lot based on the external environment input from the outside. In this embodiment, six seedling cultivation patterns are stored in the storage unit 22, so the control unit 21 selects one of the six seedling cultivation patterns based on the external environment.

[0058] The control unit 21 inputs the date and month at the start of a predetermined period for seedling cultivation under artificial light as the external environment, and selects one of the six seedling cultivation patterns based on that date and month. As mentioned above, the external environment during the predetermined period may be, for example, ambient temperature, frost occurrence, and solar radiation, so when selecting one of the six seedling cultivation patterns, the control unit 21 may use, or use, at least one of ambient temperature, frost occurrence, and solar radiation in addition to the date and month.

[0059] Furthermore, if the predetermined period is extended or shortened depending on the growth stage of the seedling T, it is preferable for the control unit 21 to select a seedling cultivation pattern based, for example, on the date at the end of the predetermined period. This increases the accuracy of estimating the external environment in which the seedling T will be grown after seedling cultivation under artificial light, making it possible to select a seedling cultivation pattern suitable for the external environment.

[0060] As explained above, according to one embodiment of the seedling cultivation method, the following effects can be obtained. (1) Since seedlings T are grown using artificial light and then further grown using a seedling cultivation pattern that includes at least one of outdoor cultivation and greenhouse cultivation, it is possible to reduce the cost required to grow seedlings T compared to growing seedlings T using artificial light alone. Furthermore, since the external environment during seedling cultivation is used to select the seedling cultivation pattern, an environment suitable for growing seedlings T that have already been grown using artificial light is selected, thereby suppressing a decrease in the yield of seedlings T.

[0061] (2) Even in seasons when it is difficult to grow seedlings T outdoors, it is possible to grow seedlings T by selecting a pattern in which greenhouse cultivation is continued. (3) Since it is possible to select either the first seedling cultivation pattern or the second seedling cultivation pattern, it is possible to set the period of greenhouse cultivation to a length that is appropriate for the time when the growth of seedlings T under artificial light begins.

[0062] (4) When it is difficult to grow seedlings T outdoors, greenhouse cultivation is carried out, while when it is possible to grow seedlings T outdoors, outdoor cultivation is carried out. Therefore, for part of the seedling period, it is possible to grow seedlings T by taking advantage of the sunlight and temperature available outdoors.

[0063] (5) By improving the accuracy of estimating the external environment when growing seedlings T that have been grown using artificial light, it is possible to improve the accuracy of selecting seedling cultivation patterns. (6) Since the cultivation of seedlings T with artificial light is suppressed even after the growth state of seedlings T exceeds the target growth state, the cost required for cultivating seedlings T is suppressed compared to when the period of cultivation of seedlings T with artificial light is fixed to a specific period. Also, since the termination of cultivation with artificial light is suppressed even if the growth state of seedlings T does not meet the target growth state, it is possible to increase the survival rate of seedlings T after seedling cultivation with artificial light compared to when the period of cultivation of seedlings T with artificial light is fixed to a specific period.

[0064] [Example of changes] The above-described embodiment can be implemented with the following modifications. [Seedling cultivation pattern] • The seedling cultivation pattern for growing mountain seedlings that do not have winter buds may also include a pattern in which seedlings are grown outdoors after being grown under artificial light, without subsequent greenhouse cultivation. In this case, if this seedling cultivation pattern is selected, outdoor cultivation will continue from the start of cultivation under this pattern until the shipment of seedling T.

[0065] This will result in the following effects. (7) During the season when it is possible to grow seedlings T outdoors, it is possible to grow seedlings T by taking advantage of the sunlight and temperature available outdoors. • Seedling cultivation patterns may include those that involve cultivation under artificial light followed by outdoor cultivation, and then greenhouse cultivation.

[0066] [Sapling] The seedling system 20 may be used to grow seedlings T of two or more tree species at the same time. In this case, it is preferable that the identification information input to the control unit 21 includes the tree species of the seedlings T. The storage unit 22 stores multiple seedling patterns for each tree species. The control unit 21 is configured to select one seedling pattern from the multiple seedling patterns associated with the tree species.

[0067] [Assessment of growth status] The determination of the growth status of seedling T may be performed not only when transitioning from artificial light cultivation to a cultivation pattern, but also when transitioning from greenhouse cultivation to outdoor cultivation, or when transitioning from outdoor cultivation to greenhouse cultivation.

[0068] When determining the growth status when transitioning from greenhouse seedling cultivation to outdoor seedling cultivation, the greenhouse 12 should be equipped with an imaging unit. Similarly, when determining the growth status when transitioning from outdoor seedling cultivation to greenhouse seedling cultivation, the field 13 should be equipped with an imaging unit. The memory unit 22 stores information regarding the growth status of seedlings T for determining their growth status.

[0069] The control unit 21 receives the image captured by the imaging unit and determines the growth status of the seedling T based on the image and the growth status information stored in the storage unit 22. If the control unit 21 determines that the growth status of the seedling T does not meet the growth status stored in the storage unit 22 at the end of a pre-set period of greenhouse or outdoor seedling cultivation, it may extend the seedling cultivation period under those conditions. Alternatively, if the control unit 21 determines that the growth status of the seedling T meets the growth status stored in the storage unit 22 during a pre-set period of greenhouse or outdoor seedling cultivation, it may shorten the seedling cultivation period under those conditions.

[0070] In the seedling cultivation method, it is not necessary to determine the growth status of the seedling T. In this case, the seedling cultivation facility 11 does not need to be equipped with an imaging unit. Also, the storage unit 22 does not need to store information regarding the growth status of the seedling T. [Explanation of Symbols]

[0071] 11...Seedling facility, 12...Greenhouse, 13...Field, 20...Seedling system, 21...Control unit, 22...Storage unit, 23...Notification unit.

Claims

1. Growing seedlings using artificial light for a predetermined period of time, Based on the growth status of the seedlings under the artificial light, the predetermined period is changed, and The process includes selecting a seedling cultivation pattern that defines a period for growing the seedlings in a greenhouse using natural light, a period for growing the seedlings outdoors, and the order of the greenhouse cultivation and outdoor cultivation, based on external environmental conditions including the date, outside temperature, occurrence of frost, and amount of sunlight at the end of the modified predetermined period, and growing the seedlings grown with artificial light according to the seedling cultivation pattern. Seedling raising method.

2. The seedling cultivation pattern includes a pattern in which greenhouse cultivation is continued from the start of seedling cultivation according to the seedling cultivation pattern until the shipment of the seedlings. The seedling cultivation method according to claim 1.

3. The seedling cultivation pattern includes a first seedling cultivation pattern in which greenhouse cultivation is continued for a first period from the start of seedling cultivation according to the seedling cultivation pattern until the shipment of the seedlings, and a second seedling cultivation pattern in which greenhouse cultivation is continued for a second period shorter than the first period from the start of seedling cultivation according to the seedling cultivation pattern until the shipment of the seedlings. The seedling cultivation method according to claim 1.

4. The seedling cultivation pattern includes a pattern in which greenhouse seedling cultivation is continued for a first period, followed by outdoor seedling cultivation for a second period. The seedling cultivation method according to claim 1.

5. The seedling cultivation pattern includes a pattern in which outdoor seedling cultivation is continued from the start of seedling cultivation according to the seedling cultivation pattern until the time of shipment of the seedlings. The seedling cultivation method according to claim 1.

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