Method for evaluating rooting of cuttings

Abstract

To provide a method for allowing convenient, accurate and efficient confirmation of rooting of a cutting in production of a rooted cutting.SOLUTION: A method of evaluating rooting of a cutting comprises: rooting and culturing a cutting of a plant as a test sample under light irradiation; measuring intensity of light irradiation of the cutting multiple times during the rooting and culturing so as to obtain light irradiation intensity measurements A1, A2, ..., An (n represents the number of measurement trials and is 2 or more); calculating differences Cx by subtracting a light compensation point B of the cutting from A1, A2, ..., An and multiplying the sum of Cx by a measurement interval (s) so as to calculate a sum D of light irradiation amounts relative to the light compensation point, according to a formula D=[C1+C2+...+Cn]*[measurement interval (s)], where if Ax-B<0 then Cx is calculated by regarding Ax-B as 0); and evaluating a rooting situation of the cutting from the sum D of light irradiation amounts relative to the light compensation point.SELECTED DRAWING: None

Description

[Technical field]

[0001] The present invention relates to a method for evaluating rooting of a cutting. [Background technology]

[0002] There are two main methods for producing containerized cutting seedlings from forest seedlings: box cutting and direct cutting into containers. In both box cutting methods, the management methods differ significantly between the "rooting culture process" (from cutting to rooting) and the "seedling raising process" after rooting (Non-Patent Documents 1 and 2). The transition from the "rooting culture process" to the "seedling raising process" has been carried out based on experience and intuition, with visual confirmation of rooting and growth of new shoots. Patent Document 1 describes a method for determining whether or not a cutting of a forest tree has taken root while being grown, in which the total transpiration / day and accumulated solar radiation from the cutting during growth are calculated, and it is determined that the cutting has taken root if the total transpiration / day converted into a value per accumulated solar radiation increases significantly, or if the total transpiration / day is calculated and converted into a value per temperature increases significantly, thereby enabling rooting to be confirmed efficiently and accurately. [Prior art documents] [Patent documents]

[0003] [Patent Document 1] Patent No. 6751626 [Non-patent literature]

[0004] [Non-Patent Document 1] Shimane Prefectural Mountainous Region Research Center, "Guide to Container Seedling Production of Japanese Cedar and Cypress (Revised Edition)," March 2018 (https: / / www.Pref.shimane.lg.jp / admin / region / kikan / chusankan / shinrin / shcn_kai.data / kontenanaetebiki_kai.pdf?site=sp) [Non-Patent Document 2] Kanto Regional Forest Office, Forest Technology and Support Center, "Container Seedling Raising Manual (Cedar Cuttings Edition)," March 31, 2016 (https: / / www.rinya.maff.go.jp / kanto / gizyutu / seika / pdf / h27sugisasiki_ikubyoumanyuaru.pdf) Summary of the Invention [Problem to be solved by the invention]

[0005] However, the method of Patent Document 1 requires a large-scale device to measure the total transpiration from the cuttings, making it difficult to measure all the seedlings. In addition, as a result of some seedlings not being accommodated in the device, there is a difference in the environment between the accommodated seedlings and the rest, making it difficult to make an accurate estimation.

[0006] An object of the present invention is to provide a method for easily, accurately and efficiently confirming the rooting of cuttings in the production of propagated seedlings. [Means for solving the problem]

[0007] The present invention provides the following [1] to

[18] . [1] Rooting a cutting of a plant as a test sample under light irradiation; During the rooting culture, measuring the amount of light irradiated to the cutting multiple times to obtain light irradiance measurement values ​​A1, A2, ... An (n represents the number of measurements and is 2 or more); Calculate the difference Cx (x is an integer between 1 and n) by subtracting the light compensation point B of the cutting from A1, A2, An according to the following formula, and multiply the sum of Cx by the measurement interval (s) to calculate the sum D of the solar radiation above the light compensation point. D=[(A1-B)+(A2-B)+...+(An-B)]*Measurement interval (s) =[C1+C2+...Cn]*Measurement interval (s) (However, if Ax-B<0, calculate Cx as Ax-B=0.) And evaluating the rooting status of the cutting from the sum D of the amount of solar radiation above the light compensation point; A method for evaluating rooting of a cutting, comprising: [2] The sum of the solar radiation above the optical compensation point D is 200 MW / m 2 The evaluation method described in [1], in which the test sample is evaluated as having rooted if the above conditions are met. [3] The sum of the solar radiation above the optical compensation point D is 200 MW / m 2 The evaluation method described in [1], in which the root culture of the test sample is evaluated as being completed if the above conditions are met. [4] The sum of the solar radiation above the optical compensation point D is 200 to 450 MW / m 2 The evaluation method described in [1], in which the root culture of the test sample is evaluated as being completed if: [5] The rooting status of the test sample is predicted as follows: Rooting a cutting of a plant of the same species as the test sample as a reference sample under light irradiation until the cutting takes root; During the rooting culture, measuring the amount of light irradiated to the cutting multiple times to obtain light irradiance measurement values ​​a1, a2, ... am (m represents the number of measurements and is 2 or more); Calculate the differences c1, c2···cm by subtracting the light compensation point b of the cutting from a1, a2···am according to the following formula, and multiply the sum of these values ​​by the measurement interval (s) to calculate the sum d of the solar radiation above the light compensation point as the reference value. d=[(a1-b)+(a2-b)+...+(am-b)]*Measurement interval(s) =[c1+c2+...cm]*Measurement interval (s) (However, if ay-b<0, calculate cy (y is an integer between 1 and m) assuming ay-b=0.) and Comparing the reference value d with the sum D of the amount of solar radiation above the light compensation point of the test sample, and evaluating the rooting state of the test sample; The evaluation method according to [1], [6] The sum of the solar radiation above the light compensation point of the test sample D but Reference value d The evaluation method described in [5], in which the test sample is evaluated as having rooted if the above conditions are met. [7] The sum of the solar radiation above the light compensation point of the test sample D but Reference value dThe evaluation method described in [5] or [6], in which the root culture of the test sample is evaluated as being completed if the above conditions are met. [8] The evaluation method according to any one of [1] to [7], wherein during rooting culture, irrigation is performed so that the moisture content of the soil is 18 to 35%. [9] During the rooting culture, the temperature of the rooting environment is measured multiple times to obtain measured values ​​E1, E2···Ep (p represents the number of measurements and is 2 or more); Calculate the differences F1 and F2···Fp by subtracting 5 from E1 and E2···Ep according to the following formula, and calculate the sum G of these differences. G = (E1-5) + (E2-5) + (Ep-5) =F1+F2+···Fp (However, if Fz-5<0, calculate Fz (z is an integer between 1 and p) assuming Fz-5=0.) and When evaluating the rooting status of cuttings, the total value G should be further referred to as the accumulated temperature; The evaluation method according to any one of [1] to [8], further comprising:

[10] The evaluation method described in [9], in which the test sample is evaluated as having rooted if the total value G is 800°C or higher.

[11] The evaluation method described in [9], in which the root culture of the test sample is evaluated as completed when the total value G is 800°C or higher.

[12] The evaluation method according to [9], in which the rooting culture of the test sample is evaluated as completed when the total value G is 800 to 1600°C.

[13] For reference of accumulated temperature, Rooting a cutting of a plant of the same species as the test sample as a reference sample under light irradiation until the cutting takes root; During the rooting culture, the temperature of the rooting environment is measured multiple times to obtain measured values ​​e1, e2, eq (q represents the number of measurements and is 2 or more); Calculate the difference (f1, f2, ... fq) by subtracting the reference temperature of 5°C from each of the following formulas, and then calculate the total value g. g = (e1-5) + (e2-5) + (eq-5) =f1+f2+···fq (However, if fw-5<0, fw (w is an integer between 1 and q) is calculated assuming fw-5=0.) Comparing the reference value g with the accumulated temperature G for the test sample to evaluate the rooting state of the test sample; The evaluation method according to [9],

[14] The evaluation method according to any one of [1] to

[13] , wherein the plant is selected from the group consisting of plants of the genus Cedar, Cypress, Pinus, Larch, Abies, and Eucalyptus.

[15] Rooting a cutting of a plant under light irradiation; and [1] to

[14] , the rooting state of the cutting as a test sample is evaluated by the evaluation method according to any one of [1] to

[14] . 16. A method for producing a plant cutting, comprising:

[16] The production method according to

[15] , wherein after the root culture is evaluated as being completed by the evaluation method according to any one of [1] to

[14] , a seedling raising process is carried out.

[17] The production method described in

[15] or

[16] , wherein during root culture, irrigation is performed so that the moisture content of the culture soil is 18 to 35%.

[18] The production method according to any one of

[15] to

[17] , wherein a seedling growth promotion treatment is carried out in the seedling growth step. Effect of the Invention

[0008] According to the present invention, in the production of cuttings, the rooting of the cuttings can be confirmed simply, accurately and efficiently, and the cuttings confirmed to have roots can show good growth. Therefore, according to the present invention, high-quality cuttings can be efficiently produced. DETAILED DESCRIPTION OF THE PREFERRED EMBODIMENTS

[0009] [1. Method for evaluating rooting of cuttings] In the present invention, a plant cutting (test sample) is cultured to cause rooting under light irradiation, and the amount of light irradiated to the cutting is measured. The difference is calculated by subtracting the light compensation point from the measured light irradiance value, and the rooting status of the cutting is evaluated from the sum of these values.

[0010] [Plant cuttings] The test samples were plant cuttings.

[0011] -plant- The plant species may be either woody or herbaceous, with woody plants being preferred, and woody plants being more preferred as they generally have inferior rooting ability to herbaceous plants. Examples of woody plants include Cryptomeria plants (such as Cryptomeria japonica), Chamaecyparis plants (such as Chamaecyparis obtusa), Pinaceae plants (Pinus plants (Pinus thunbergii, etc.), Larix plants (Larix kaempferi, Larix gmelinii, etc.), Abies plants (Abies sachalinensis, etc.), Eucalyptus plants, Prunus plants (Prunus spp., Prunus mume, Prunus tomentosa, etc.), tomentosa), Mangifera plants (Mango (Mangifera indica), Acacia plants, Myrica plants, Quercus plants (Quercus acutissima), Vitis plants, Malus plants, Rosa plants, Camellia plants (Camellia sinensis), Jacaranda plants (Jacaranda mimosifolia), Persea plants (Avocado (Persea americana), Pyrus plants (Pyrus serotina Rehder, Pyrus pyrifolia), Santalum plants (Sandalwood; Santalum Examples include a music video album.Among these, cedar, cypress, pine (Japanese black pine, larch, gmelin, todomatsu, etc.), eucalyptus, cherry, mango, avocado, acacia, bayberry, sawtooth oak, grape, apple, rose, camellia, tea, plum, toadflax, and jacarantha can be mentioned, and among them, plants of the genus Cryptomeria japonica, plants of the genus Chamaecyparis obtusifolia, plants of the family Pinaceae (plants of the genus Pinus, larch, fir, etc.), plants of the genus Eucalyptus, plants of the genus Camellia, plants of the genus Mangifera, and plants of the genus Alligator are preferred, and forest seedlings, i.e., plants of the genus Cryptomeria japonica, plants of the genus Pinus, plants of the genus Larch, plants of the genus Fir, and plants of the genus Eucalyptus are more preferred, and plants of the genus Cryptomeria japonica, plants of the genus Cypress, plants of the genus Pinus, plants of the genus Larch, plants of the genus Fir, and plants of the genus Eucalyptus are even more preferred.

[0012] -Cuttings- The cutting may be at least a part of the plant body, and examples thereof include branches such as green branches and mature branches; buds such as terminal buds and axillary buds; leaves, cotyledons, and hypocotyls. Cuttings of woody plants generally include at least green branches or mature branches. It is preferable that the cutting includes at least a shoot. This can facilitate the formation of adventitious roots. The shoot refers to a tissue having rooting ability, and examples thereof include branches, stems, buds, terminal buds, axillary buds, adventitious buds, leaves, cotyledons, hypocotyls, adventitious embryos, shoot primordia, and multiple shoots derived from these specific examples (JP Patent Publication 8-228621), and the terminal bud is preferable. In the present invention, a branch including at least one shoot (preferably a terminal bud) can be efficiently obtained. The cutting may be taken from the mother tree from which the cutting is taken, or may be taken from a plant body other than the mother tree from which the cutting is taken.

[0013] The size of the cuttings to be harvested is usually 40 cm or less or 35 cm or less, preferably 33 cm or less, more preferably 32 cm or less, and even more preferably 31 cm or less. There is no particular lower limit, but it is usually 1 cm or more or 2 cm or more, preferably 3 cm or more, more preferably 4 cm or more, and even more preferably 5 cm or more.

[0014] -How to insert- At the start of rooting culture, the cutting is inserted into the culture soil according to the type of culture soil, the environment, the type of cutting, and other conditions. For example, a method of inserting a part of the cutting including the base (for example, 1 cm to 6 cm from the base, preferably 1.5 cm to 6 cm, more preferably 2 cm to 5 cm) into the culture soil can be mentioned. The base of the cutting means an end of the cutting where the roots are formed (opposite the end where the leaves are formed). The base of the multiple shoot is a region having a cut surface when dividing the multiple shoot. When inserting, physical stimulation may be applied to the cutting (for example, the base is scratched). This can improve the rooting rate. The size (for example, size, shape) of the scratch to be made at the base is not particularly limited. For example, a cross-shaped scratch can be made at the base (the above-mentioned cut surface) of the multiple shoot, which is the cutting. For example, scissors and a knife can be used as tools for scratching. It is preferable to cut off the leaves at the portion of the base of the cutting that will be inserted into the support (for example, about 3 cm from the tip of the base).

[0015] [Rooting culture] -Light irradiation- The test sample is cultured under light irradiation. The method and amount of light irradiation can be appropriately set depending on the plant species, and may be natural conditions (natural light) or may be artificially controlled using an artificial sunlight room, LED, etc. The amount of light is not particularly limited, but it is preferable to block light irradiation under natural conditions. This can promote rooting. The shading rate is preferably 30% to 70%, more preferably 40% to 60%.

[0016] -Cultivating soil moisture content- Rooting culture is carried out under conditions where the moisture content of the culture soil is preferably 18 to 35%, more preferably 20 to 30%. This allows for more accurate prediction of rooting. In this specification, the moisture content of the culture soil is the weight of water (%) per volume of the culture soil. The moisture content of the culture soil can be adjusted by adjusting the culture conditions such as irrigation conditions (frequency and amount of irrigation, etc.), type of culture soil, temperature, humidity, etc. The moisture content of the culture soil can be measured using a soil moisture sensor.

[0017] -Irrigation- The irrigation method may be, for example, overhead irrigation or bottom irrigation. The bottom irrigation method may be, for example, a method of immersing a culture vessel (equipped with a water port) containing the culture soil with the cuttings in it in water, or a method of irrigating the cuttings through a water-absorbing member. When bottom irrigation is performed through a water-absorbing member, water is usually supplied to the water-absorbing member (for example, a mat-shaped member), and the moisture is supplied to the cuttings through the part where the culture soil and the water-absorbing member are in contact. It is preferable to supply water to the water-absorbing member so that the culture soil is moistened and / or so that the water-absorbing member is in a state where it uniformly absorbs water. This allows the moisture environment of the culture soil to be maintained moderately, consistently, and uniformly. The irrigation work may be performed by either hand irrigation or an automatic irrigation device.

[0018] -Cultivating soil- The culture soil may be any one that is normally used for growing plants, and examples of the culture soil include natural soil such as sand and soil (e.g., Akadama soil, Kanuma soil). Other examples of the culture soil include artificial soil such as rice husk charcoal, coconut fiber, vermiculite, perlite, peat moss, and glass beads; porous molded products such as foamed phenolic resin and rock wool; and solidifying agents (e.g., agar or gellan gum), and at least one selected from these may be used in place of or together with natural soil. The culture soil may be stored in a container. As the container, a conventional container may be used.

[0019] -temperature- Examples of temperature conditions include a daytime temperature of 15 to 35° C. (preferably 20 to 35° C.) and a nighttime temperature of 10 to 25° C. (preferably 10 to 20° C., more preferably 15 to 20° C.). The growing location is not particularly limited and may be either a closed space (e.g., in a vinyl house, in an artificial sunlight room, in a greenhouse, or indoors) or an open space (e.g., outdoors).

[0020] -Humidity- The humidity can be adjusted according to the cultivation conditions such as the type of plant, but is usually 50% or more, preferably 60% or more. This promotes root growth from the plant and allows efficient seedling cultivation. There is no particular upper limit.

[0021] -Insertion time- The time for cuttings (when rooting culture begins) is not particularly limited and depends on the average temperature of the region and the location (indoors or outdoors), but is preferably from December to May, more preferably from February to early April, and even more preferably from February to March.

[0022] -Culture container- In the case of rooting culture, a culture vessel for storing culture soil may be used. This allows smooth operation. The culture vessel preferably has a water passage (net, fine holes) at the bottom. This allows it to be used for bottom watering. For example, containers (e.g., containers described in JP 2017-079706 A, multi-cavity containers (JFA-150, JFA-300), etc.), cell trays, seedling pots, planters, and trays, box-shaped containers with net-like openings on the bottom or side, etc. may be used. The culture vessel may be a type in which one cutting is planted in one container, or a type in which two or more cuttings are planted in one container. The material of the culture vessel is not particularly limited, and examples thereof include resin, glass, and wood.

[0023] [Measurement of light irradiation amount] In rooting evaluation, the amount of light irradiated to the cutting is measured multiple times during rooting culture. The measurement may be performed multiple times (n times) irregularly or periodically (preferably periodically) during rooting culture, and the number of times is not particularly limited, but it is preferable to perform the measurement over time from the start of rooting culture, more preferably at 1 to 5 minute intervals, and more preferably at 2 to 3 minute intervals. The amount of light irradiated can be measured using a solar radiation sensor placed near the culture soil. The measurement interval of the amount of solar radiation is preferably regular, and can be set, for example, between 1 to 5 minutes, preferably 2 to 3 minutes, and more preferably 2 minutes. The sum D of the amount of solar radiation above the light compensation point is calculated from the values ​​obtained at each measurement. In this specification, the measured value of the amount of light irradiated obtained in the xth measurement is represented as Ax. For example, if the number of measurements is n, A1 (the measured value at the first measurement), A2 (the measured value at the second measurement), ... An (the measured value at the nth measurement).

[0024] [Calculation of the sum D of solar radiation above the light compensation point] In rooting evaluation, after calculating the measured values ​​of the above light irradiance, the sum D of the light irradiance above the light compensation point of the cutting is calculated. That is, according to the following formula, the differences C1, C2...Cn are calculated by subtracting the light compensation point B of the cutting from A1, A2...An, and the sum C of these is obtained. The sum C is then multiplied by the measurement time (s) to calculate the sum (total value) D of the light irradiance above the light compensation point. D=[(A1-B)+(A2-B)+...+(An-B)]*Measurement time (s) =[C1+C2+...Cn]*Measurement interval (s)=C*Measurement interval (s) However, if Ax-B<0, Cx is calculated assuming Ax-B=0 (x is an integer between 1 and n). Sum of solar radiation above the light compensation point Since D is considered to correspond to the amount of energy that the cutting can use for photosynthesis out of the amount of light irradiation, it can evaluate rooting more accurately than the simple integrated value of light irradiation. The light compensation point B is uniquely determined for each plant. For example, the light compensation point of Japanese cedar is 7.9 W / m 2 , the light compensation point of cypress is 19.5W / m 2 It is.

[0025] [Evaluation of rooting status] The rooting evaluation was performed as described above. Sum of solar radiation above the light compensation point The rooting status of the cuttings is evaluated from D. This makes it possible to omit visual confirmation of the rooting status of the cuttings, and improves the efficiency of seedling raising. In particular, this is more efficient when raising multiple cuttings.

[0026] -Evaluation example 1-1 (evaluation based on specified numerical values)- An example of an evaluation is: Sum of solar radiation above the light compensation point on the test sample D is 200MW / m 2 More than 210MW / m 2 In the above cases, it can be evaluated that the test sample has rooted and the rooting culture process is complete. An upper limit can also be set, for example, 450 MW / m 2 Before exceeding 420 MW / m 2It can be evaluated that the rooting culture process should be completed (the next process (e.g., seedling raising process) should be started (e.g., seedling promotion treatment (top dressing, transplanting into seedling containers, etc.) should be performed)) before the temperature exceeds this value.

[0027] -Evaluation Example 1-2 (Evaluation based on the standard value c obtained in a preliminary test using a standard sample)- As another example of the evaluation, the total amount of light irradiation at or above the light compensation point b (usually b ≒ B, preferably b = B) of the cutting obtained in a preliminary test using a cutting (reference sample) of the same or closely related plant species as the test sample is defined as a reference value d, and the total amount of light irradiation at or above the light compensation point b (usually b ≒ B, preferably b = B) of the cutting is compared with the reference value d. Sum of solar radiation above the light compensation point on the test sample The rooting status of the cutting can be evaluated by comparing with D. The reference value d can be obtained by culturing a reference sample under light irradiation until the cutting roots, measuring the light irradiation amount multiple times (assumed to be m times; m may be the same as n or different, but is preferably the same) irregularly or periodically (preferably periodically) during the rooting culture to obtain light irradiation amount measurements a1, a2,...am (m represents the number of measurements and is 2 or more), calculating the difference (c1, c2,...cm) obtained by subtracting the light compensation point B of the plant from each of the measurements, and multiplying the sum c of these values ​​by the measurement interval (s), that is, by the following formula. d=[(a1-b)+(a2-b)+...+(am-b)]: Measurement interval (s) =[c1+c2+...cn]*Measurement interval (s)=c*Measurement interval (s) However, if ay-b<0, cy is calculated assuming ay-b=0 (y is an integer between 1 and m).

[0028] It is preferable that the rooting culture conditions, the number of light irradiation measurements, and the intervals for the reference sample are substantially the same as those for the test sample. Sum of solar radiation above the light compensation point When D is equal to or greater than the reference value d, it can be evaluated that the test sample has rooted and the rooting culture process is complete. When D is significantly greater than the reference value d (for example, the reference value d + 2.0 MW / m 2exceeding this threshold), it can be evaluated that the rooting culture process should be terminated (that the next process (e.g., seedling raising process) should be started (for example, seedling promotion treatment (top dressing, transplanting into seedling containers, etc.) should be performed).

[0029] [Evaluation of rooting status based on accumulated temperature] When evaluating the rooting status, the accumulated temperature of the rooting environment during rooting culture may be referred to. This allows for more accurate rooting evaluation. The accumulated temperature of the rooting environment is the accumulated value of the temperature during the rooting culture period, and can be obtained by measuring the temperature of the rooting environment multiple times, either irregularly or periodically (preferably regularly), to obtain measured values ​​E1, E2, ...Ep (p represents the number of measurements, which is 2 or more. The number of days during the measurement period (daily) is preferable), and the difference (F1, F2, ...Fp) is calculated by subtracting the reference temperature of 5°C from each of them, and the sum G of these values ​​can be calculated using the following formula. G = (E1-5) + (E2-5) + (Ep-5) =F1+F2+···Fp However, if Fz-5<0, Fz is calculated assuming Fz-5=0 (z is an integer between 1 and p). The measured temperature value Ez is preferably the average temperature over a day. Ez may be measured using a temperature sensor according to conventional methods.

[0030] -Evaluation example 2-1 (Evaluation based on specified numerical values)- As an example of the evaluation taking the accumulated temperature into consideration, when the total value G is 800°C or more, preferably 900°C or more, together with the evaluation by the amount of light irradiation, it can be evaluated that the test sample has rooted and the rooting culture process is completed. An upper limit can also be set, and it can be evaluated that the rooting culture process should be completed (the next process (e.g., seedling raising process) should be moved to (e.g., seedling promotion treatment (top dressing treatment, transplanting into seedling container, etc.) should be performed)) before exceeding 1600°C.

[0031] -Evaluation Example 2-2 (Evaluation based on the standard value g obtained in a preliminary test using a standard sample)- As another example of the evaluation, the total value (accumulated temperature) of temperatures equal to or higher than the reference temperature during the preliminary test period obtained in a preliminary test using cuttings (reference samples) of the same plant species as the test sample can be used as the reference value g, and the rooting status of the cuttings can be evaluated by comparing the reference value g with the total value G. The reference value g can be obtained by culturing the reference sample under light irradiation until the cuttings root, measuring the temperature of the seedling environment multiple times irregularly or periodically (preferably periodically) during the rooting culture to obtain measured values ​​e1, e2, . . . eq (q represents the number of measurements and is 2 or more. The number of days during the measurement period (every day) is preferable; q may be the same as p or different, but is preferably the same), calculating the difference (f1, f2, . . . fq) by subtracting the reference temperature of 5°C from each of them, and calculating the total value g by the following formula. g = (e1-5) + (e2-5) + (eq-5) =f1+f2+···fq However, if fw-5<0, fw is calculated as fw-5=0 (w is an integer between 1 and q). The measured temperature value ew is preferably the average temperature over a day. ew may be measured using a temperature sensor in accordance with conventional methods.

[0032] It is preferable that the rooting culture conditions, number of temperature measurements, and intervals for the reference sample are substantially the same as those for the test sample. If the total value G for the test sample is equal to or greater than the reference value g, it can be evaluated that the test sample has rooted and the rooting culture process has been completed. If the total value G is significantly greater than the reference value g (for example, if it exceeds the reference value g + 500°C), it can be evaluated that the rooting culture process should be completed (the next process (for example, the seedling raising process) should be started (for example, seedling promotion treatment (top dressing, replanting in a seedling raising container, etc.) should be performed)).

[0033] [Rooting promotion treatment] During the rooting culture period, rooting promotion treatment may be performed as necessary. Examples of rooting promotion treatment include administration of additives, shading (e.g., shading using cheesecloth), adjusting carbon dioxide concentration, humidity adjustment, temperature adjustment, and other treatments to adjust the rooting environment for the purpose of promoting rooting, and two or more treatments may be combined. The type and implementation conditions of the rooting promotion treatment may be appropriately determined depending on the plant species, part, size, etc., and may be appropriately selected from the treatments exemplified below.

[0034] [2. How to produce cuttings] The above evaluation method can be used for production management of cuttings. For example, a cutting of a plant is cultured under light irradiation, and the rooting state is evaluated by the above evaluation method. After the rooting culture is evaluated as being completed, the rooting culture process is terminated and the seedling cultivation process can be started. The seedling cultivation process can be carried out in a seedling cultivation medium. Examples of the seedling cultivation medium are the same as the examples of the rooting culture medium, and the rooting culture medium may be used as it is or may be changed. A seedling cultivation container for storing the seedling culture medium may be used. Examples of the seedling cultivation container are the same as the examples of the culture container in the rooting culture, and the culture container in the rooting culture may be used as it is as the seedling cultivation container, or may be replanted when moving to the seedling cultivation process. Examples of the location, temperature, and humidity conditions for carrying out the seedling cultivation process are the same as those for the rooting culture except that light is not shielded, and may be the same conditions as those for the rooting culture. In addition, an acclimation process may be carried out before carrying out the seedling cultivation process after the completion of the rooting culture.

[0035] [Seedling promotion treatment] During the seedling raising period, seedling growth promotion treatment may be performed as necessary. Examples of seedling growth promotion treatment include administration of additives (e.g., plant hormones, inorganic components, fertilizers), transplantation (exchange of culture medium), temperature and humidity adjustment, and other seedling environment adjustment treatments for the purpose of promoting seedling growth, and two or more treatments may be combined. The type and implementation conditions of the seedling growth promotion treatment may be appropriately determined depending on the plant species, part, size, etc., and may be appropriately selected from the treatments exemplified below.

[0036] [Optional seedling raising conditions] In the present invention, the conditions for the rooting culture (both the test sample and the reference sample) other than those described above and the conditions for raising the seedlings after the rooting may be carried out according to conventional methods and are not particularly limited.

[0037] -Additives- The culture medium may contain additives that are usually used when plant cuttings are used. Examples of additives include known culture media for plant tissue culture and aqueous solvents (e.g., water), with aqueous solvents being preferred, and water being more preferred. Examples of culture media for plant tissue culture include MS medium, Linsmeyer-Skoog medium, White medium, Gamborg's B-5 medium, and Niche Niche medium. Among these, MS medium and Gamborg's B-5 medium are preferred. These media can be used after appropriate dilution as necessary. The medium may be either a liquid medium or a solid medium, but a liquid medium is preferred in terms of work efficiency and less damage to roots during transplantation. The liquid medium can be prepared by mixing the medium components and used as is. The solid medium can be used by mixing the medium components and solidifying them with a solidifying agent (e.g., agar, gellan gum) at the same time as or after preparation, as in the case of the liquid medium. The amount of the solidifying agent added can be appropriately set depending on conditions such as the type of solidifying agent and the composition of the medium. The amount of agar added to the medium is preferably 0.5 to 1% by weight. The amount of gellan gum added to the medium is preferably 0.2 to 0.3% by weight.

[0038] The additives are optional and may be additives used when rooting cuttings or additives used during subsequent seedling cultivation. Examples include fertilizers (e.g., inorganic components, silver ions, antioxidants, carbon sources, vitamins, amino acids, plant hormones), rooting promoters other than those mentioned above (e.g., agents described in documents such as International Publication No. 2011 / 136285, JP 2012-232907 A, and JP 2013-95664 A). The form of each component is not particularly limited, and may be either a solid (e.g., tablet, powder, granule) or a liquid (e.g., liquid fertilizer). In addition, the components constituting the additives may be mixed, absorbed, or sprayed in the culture soil, or may be directly sprayed, applied, or sprayed on at least a part of the cutting.

[0039] The additives may be mixed together or at least partially separately and then incorporated into the support, or the additives may be added to the medium beforehand and then incorporated into the support. The additives may also be applied (e.g., coated or sprayed) directly to the cutting (preferably the base).

[0040] Examples of inorganic components include elements such as nitrogen, phosphorus, potassium, sulfur, calcium, magnesium, iron, manganese, zinc, boron, molybdenum, chlorine, iodine, and cobalt, and inorganic salts containing these. Examples of the inorganic salt include potassium nitrate, ammonium nitrate, ammonium chloride, sodium nitrate, potassium monohydrogen phosphate, sodium dihydrogen phosphate, potassium chloride, magnesium sulfate, ferrous sulfate, ferric sulfate, manganese sulfate, zinc sulfate, copper sulfate, sodium sulfate, calcium chloride, magnesium chloride, boric acid, molybdenum trioxide, sodium molybdate, potassium iodide, cobalt chloride, and hydrates thereof. The inorganic components may be one type alone or two or more types in combination, and preferably contain at least one type selected from nitrogen, phosphorus, potassium, magnesium, inorganic salts containing nitrogen, inorganic salts containing phosphorus, and inorganic salts containing potassium. When one type of inorganic component is contained in the above-mentioned known medium, the amount in the medium is preferably 0.1 μM to 100 mM, more preferably 1 μM to 100 mM. In the case of a combination of two or more kinds, the amount of each in the medium is preferably 0.1 μM to 100 mM, more preferably 1 μM to 100 mM.

[0041] Examples of silver ions include silver compounds (silver ion sources) such as silver thiosulfate (STS, AgS4O6) and silver nitrate, and may be used alone or in combination of two or more, with STS being preferred. STS is presumed to take the form of silver thiosulfate ions in the medium and to be negatively charged, which can contribute to promoting healthy root growth and elongation. When silver ions are contained in the above-mentioned medium, the amount of the silver ion source in the medium is preferably 0.5 μM to 6 μM, more preferably 2 μM to 6 μM.

[0042] Examples of antioxidants include ascorbic acid and sulfites, with ascorbic acid being preferred. Ascorbic acid has low residual capacity in the medium, and therefore can prevent environmental pollution. When antioxidants are contained in the medium, the amount is preferably 5 mg / l to 200 mg / l, and more preferably 20 mg / l to 100 mg / l.

[0043] Examples of carbon sources include carbohydrates such as sucrose and its derivatives; organic acids such as fatty acids; and primary alcohols such as ethanol. The carbon source may be one of the above specific examples, or two or more may be used in combination. When the carbon source is contained in the medium, the amount is preferably 1 g / l to 100 g / l, more preferably 10 g / l to 100 g / l. When rooting culture is performed by supplying carbon dioxide gas, the rooting medium does not need to contain a carbon source, and preferably does not contain one. Organic compounds that can be carbon sources such as sucrose also serve as carbon sources for microorganisms, so when using a rooting medium containing these compounds, it is necessary to perform cultivation in a sterile environment. However, by performing rooting culture by supplying carbon dioxide gas, the addition of a carbon source to the rooting medium can be omitted, and cultivation in a non-sterile environment is possible.

[0044] Examples of vitamins that can be used include biotin, thiamine (vitamin B1), pyridoxine (vitamin B4), pyridoxal, pyridoxamine, calcium pantothenate, inositol, nicotinic acid, nicotinamide, and / or riboflavin (vitamin B2). One vitamin may be selected from the above specific examples, or two or more vitamins may be used in combination. When one vitamin is added to the medium, the amount is preferably 0.01 mg / l to 200 mg / l, more preferably 0.02 mg / l to 100 mg / l. When a combination of two or more vitamins is added, the amount of each vitamin is preferably 0.01 mg / l to 150 mg / l, more preferably 0.02 mg / l to 100 mg / l.

[0045] Examples of amino acids include glycine, alanine, glutamic acid, cysteine, phenylalanine, and lysine. The amino acids may be used singly or in combination of two or more. When one type of amino acid is added to the above-mentioned medium, the amount is preferably 0.1 mg / l to 1000 mg / l, and when two or more types are added in combination, the amount of each amino acid in the medium is preferably 0.2 mg / l to 1000 mg / l.

[0046] Examples of plant hormones include rooting promoters such as auxins and cytokinins. Examples of auxins include naphthalene acetic acid (NAA), indole acetic acid (IAA), p-chlorophenoxy acetic acid, 2,4-dichlorophenoxy acetic acid (2,4D), indole butyric acid (IBA), and derivatives thereof, and may be one or a combination of two or more of these. Examples of auxins include NAA and IBA. Examples of cytokinins include benzyladenine (BA), kinetin, zeatin, and derivatives thereof, and may be one or a combination of two or more of these. Examples of plant hormones include one or a combination of two or more of these, and preferably include auxin or a combination of auxin and cytokinin.

[0047] When one type of plant hormone is added to the medium, the amount is preferably 0.001 mg / l to 10 mg / l, more preferably 0.01 mg / l to 10 mg / l. When a combination of two or more types is added, the amount of each is preferably 0.001 mg / l to 10 mg / l, more preferably 0.01 mg / l to 10 mg / l. The method of adding the plant hormone may be in accordance with the instructions of the commercially available product. For example, a method of directly applying a powder of the plant hormone (e.g., auxin) to the base of the cutting (preferably the base to which a physical stimulus has been applied) before cutting, or a method of adding the powder to a support may be mentioned.

[0048] The timing of adding additives varies depending on the type of additive, and is not particularly limited. For example, plant hormones (e.g., auxin) can be added at the start of rooting culture. Inorganic components (e.g., fertilizers containing nitrogen, phosphorus, potassium, and magnesium) may be added (top dressing) after rooting is confirmed. The method of addition depends on the form of the component, but examples include scattering, wetting, and spraying. The number of additions is also not particularly limited, and may be only once (at the start of culture) or two or more times (at the start of culture and during culture). In addition, the components constituting the rooting medium may be added together or separately, or may be appropriately replaced or replenished during the course of culture.

[0049] - Carbon dioxide concentration, humidity - Carbon dioxide gas is preferably supplied to the cultivation environment at a concentration of 300 ppm to 2000 ppm, preferably 800 ppm to 1500 ppm. The amount of carbon dioxide gas supplied can be controlled using equipment such as an artificial weather chamber or a culture vessel having a carbon dioxide permeable membrane at an opening.

[0050] The humidity can be adjusted according to the cultivation conditions such as the type of plant, but is usually 50% or more, preferably 60% or more. This promotes root growth from the plant and allows efficient seedling cultivation. There is no particular upper limit.

[0051] -Irrigation- The irrigation method may be either overhead or bottom irrigation, and the irrigation work may be either manual or automatic irrigation equipment.

[0052] -Place for seedlings- The place where the seedlings are raised may be a closed space (e.g., in a vinyl house, a carbon dioxide gas culture room, a greenhouse, or indoors) or an open space (e.g., outdoors), but a closed space is preferable for the first few months (e.g., up to the 2nd or 3rd month) after the start of seedling raising. This makes it easier to adjust conditions such as temperature and humidity.

[0053] -temperature- The temperature in the environment for rooting and growing seedlings is not particularly limited as long as the conditions allow seedling growth, but is preferably 20 to 40°C, for example.

[0054] -period- The rooting culture period is as described above. The seedling raising period should continue at least until the seedlings are observed, and is usually 4 months or more, preferably 6 months or more, and more preferably 8 months or more. It is preferable to continue raising the seedlings until the seedlings reach a height of about 30 cm or more, and even after the seedlings are observed, the seedlings may be raised using the above-mentioned culture soil and seedling raising container, or they may be transferred to another culture soil and continued to be raised. EXAMPLES

[0055] The present invention will be described in detail with reference to examples, but the present invention is not limited to the following examples.

[0056] Example 1 On April 1, 2020, branches were harvested from a mother cedar tree, and cuttings of about 30 cm in length were prepared. Akadama soil small grains (Yamato Plastics, seedling box type B) were filled into a seedling box to prepare a cutting bed. 5 to 10 mg of Rooton (registered trademark) powder (Ishihara Biosciences, white powder containing the plant hormone NAA, NAA concentration is 0.4%) was applied to the base (cut part) of the cutting prepared as described above, and the cutting was inserted into the cutting bed about 5 cm from the base. The seedling box with the cutting inserted was placed on an outdoor seedling shelf, and a moisture sensor (WD-3, ARP Co., Ltd.) was installed to measure the moisture content of the soil. A solar radiation sensor (solar radiation meter with logger, Sanshosha Co., Ltd.) was installed next to the seedling box to measure the amount of solar radiation. During rooting culture, an automatic sprinkler was used to maintain the soil moisture content at 25%. A solar radiation sensor measured the amount of solar radiation once every two minutes, and the sum of the amount of solar radiation above the light compensation point of the cedar was calculated. The accumulated temperature was calculated by measuring the temperature once every two minutes to calculate the average temperature over 24 hours in a day, from which the reference temperature (5°C) was subtracted to calculate the temperature per day, and the sum of the values ​​calculated for each day was taken as the accumulated temperature. An Ondotori (T&D) measuring device was used, and was placed next to the seedling boxes.

[0057] The total amount of solar radiation is 236MW / m 2 When the seedling height exceeded this limit, the seedlings were replanted in a seedling container (multi-cavity container). Akadama soil (Yanagishima Shoji Co., Ltd.) and peat moss (Toho Co., Ltd.) were mixed in a 1:1 ratio and filled into the seedling container to create seedling soil. The cedar seedlings replanted in the seedling container were placed on outdoor seedling shelves and continued to be managed. The growth of the cedar seedlings was measured on November 1, 2020, and seedlings with a height of 35 cm or more and a base diameter of 5.5 mm or more were harvested to calculate the seedling yield rate (Table 1).

[0058] Example 2 For transplanting into a nursery container, the total amount of solar radiation above the light compensation point of the cedar tree is 360MW / m 2 The rest of the experiment was carried out in the same manner as in Example 1 (Table 1).

[0059] Example 3 For transplanting into a nursery container, the total amount of solar radiation above the light compensation point of the cedar tree is 396MW / m 2 The rest of the experiment was carried out in the same manner as in Example 1 (Table 1).

[0060] Example 4 On April 1, 2020, branches were harvested from the mother cypress tree, and cuttings of about 30 cm in length were prepared. As in Example 1, the amount of solar radiation and temperature were measured over time, and the sum of the amount of solar radiation above the light compensation point of the cypress and the integrated temperature were calculated. 2 When the height exceeded 100 cm, the seedlings were replanted in a seedling container. On November 1, 2020, the growth of the cypress seedlings was measured, and the seedling yield rate was calculated assuming that the seedlings were 30 cm or more in height and 3.5 mm or more in base diameter. The rest was carried out in the same manner as in Example 1 (Table 1).

[0061] Comparative Example 1 Watering was performed when it was visually confirmed that the surface of the cutting bed was dry. Repotting was performed before it was confirmed that the roots had grown from the bottom of the seedling box. The rest of the experiment was performed in the same manner as in Example 1 (Table 1).

[0062] Comparative Example 2 The transplantation work was carried out after confirming that the roots had sufficiently grown from the bottom of the seedling box. The rest was carried out in the same manner as in Example 1 (Table 1).

[0063] [Table 1]

[0064] Compared to Comparison Examples 1 and 2, in which transplanting was performed without calculating the sum of the solar radiation above the light compensation point, Examples 1 to 4, in which the sum of the solar radiation was calculated and confirmed, had a high rooting rate and seedling yield rate, and seedlings with large seedling height and base diameter were obtained (Table 1).

[0065] Example 5 On April 1, 2020, branches were harvested from a mother cedar tree and cuttings approximately 30 cm in length were prepared. A multi-cavity container was used as a culture vessel, and Akadama small grain soil (Yanagishima Shoji Co., Ltd.) and peat moss (Toho Co., Ltd.) were mixed in a 1:1 ratio and filled to prepare a cutting bed. 5 to 10 mg of Rooton (registered trademark) powder (Ishihara Biosciences Co., Ltd., white powder containing the plant hormone NAA, NAA concentration is 0.4%) was applied to the base (cut part) of the cutting prepared as described above, and the cutting was inserted into the cutting bed about 5 cm from the base. The seedling container with the cutting was placed on an outdoor seedling shelf, and a moisture sensor (WD-3, ARP Co., Ltd.) was installed to measure the moisture content of the culture soil. A solar radiation sensor (solar logger-equipped pyranometer, Sanshosha Co., Ltd.) was installed next to the seedling container to measure the amount of solar radiation. During rooting culture, an automatic sprinkler was used to maintain the moisture content of the culture soil at 20 to 25%. The amount of solar radiation was measured at intervals of once every two minutes using a solar radiation sensor, and the sum of the amounts of solar radiation above the light compensation point of the cedar was calculated. The integrated temperature was calculated in the same manner as in Example 1.

[0066] The total amount of solar radiation is 236MW / m 2When the height exceeded this limit, Promic tablets, slow-release medium grain (6-8-8) (manufactured by Hyponex) were applied as a top dressing. On November 1, 2020, the growth of the cedar seedlings was measured, and those with a height of 35 cm or more and a base diameter of 5.5 mm or more were harvested to calculate the harvest rate (Table 2).

[0067] Example 6 Top dressing is required when the total amount of solar radiation above the light compensation point of cedar is 360MW / m 2 The rest of the procedure was the same as in Example 5 (Table 2).

[0068] Example 7 For top dressing, the total amount of solar radiation above the light compensation point of cedar is 396MW / m 2 The rest of the procedure was the same as in Example 5 (Table 2).

[0069] Example 8 On April 1, 2020, branches were harvested from the mother cypress tree and cuttings of approximately 30 cm in length were prepared. A solar radiation sensor was used to measure the amount of solar radiation at intervals of once every two minutes, and the sum of the solar radiation above the light compensation point of the cypress was calculated to be 360 ​​MW / m 2 When the growth rate exceeded 100%, Promic Tablets Slow-acting Medium Grain (6-8-8) (manufactured by Hyponex) was given as a top dressing. On November 1, 2020, the growth amount of cypress seedlings was measured, and seedlings with a height of 30 cm or more and a root diameter of 3.5 mm or more were obtained and the seedling yield rate was calculated. The rest was carried out in the same manner as in Example 5 (Table 2).

[0070] Comparative Example 3 Watering was performed when it was confirmed that the surface of the cutting bed was dry by visual inspection. Top dressing was performed before the roots began to grow from the bottom of the seedling container. The rest of the experiment was performed in the same manner as in Example 5 (Table 2).

[0071] Comparative Example 4 Watering was performed when it was confirmed that the surface of the cutting bed was dry by visual inspection. Top dressing was performed after it was confirmed that the roots had sufficiently grown from the bottom of the seedling container. The rest was performed in the same manner as in Example 5 (Table 2).

[0072] [Table 2]

[0073] Compared to comparison examples 3 and 4, in which top dressing was applied without calculating the sum of the solar radiation above the light compensation point, examples 5 to 9, in which the sum of the solar radiation was calculated and confirmed, produced seedlings with high rooting rates and seedling yield rates, as well as large seedling heights and root diameters. These examples show that, according to the present invention, it is possible to easily, accurately and efficiently confirm the rooting of cuttings, and cuttings that have been confirmed to have roots can show good growth, thereby enabling the efficient production of high-quality rooted cuttings.

Claims

1. Rooting a cutting of a plant as a test sample under light irradiation; During the rooting culture, the amount of light irradiated to the cutting is measured multiple times to obtain light irradiance measurement values ​​A1, A2, ... An (n represents the number of measurements and is 2 or more); Calculate the difference Cx (x is an integer between 1 and n) by subtracting the light compensation point B of the cutting from A1, A2, ..., An according to the following formula, and multiply the sum of Cx by the measurement interval (s) to calculate the sum D of the solar radiation above the light compensation point; D=[(A1-B)+(A2-B)+...+(An-B)]*Measurement interval (s) = [C1+C2+...Cn]*Measurement interval (s) (However, if Ax-B<0, Cx is calculated assuming Ax-B=0.) And evaluating the rooting status of the cutting from the sum D of the amount of solar radiation above the light compensation point; A method for evaluating rooting of a cutting, comprising:

2. The sum of the solar radiation above the light compensation point D is 200 MW / m 2 The evaluation method according to claim 1, wherein the test sample is evaluated as having rooted if the above conditions are met.

3. The sum of the solar radiation above the light compensation point D is 200 MW / m 2 The evaluation method according to claim 1 , wherein the root culture of the test sample is evaluated as complete when the above conditions are met.

4. The sum of the solar radiation above the light compensation point D is 200 to 450 MW / m 2 The method according to claim 1, wherein the rooting culture of the test sample is evaluated as being complete when

5. The prediction of the rooting status of the test sample is as follows: Rooting a cutting of a plant of the same species as the test sample as a reference sample under light irradiation until the cutting takes root; During the rooting culture, the amount of light irradiated to the cutting is measured multiple times to obtain light irradiance measurement values ​​a1, a2, ..., am (m represents the number of measurements and is 2 or more); According to the following formula, the difference c1, c2, ... cm is calculated by subtracting the light compensation point b of the cutting from a1, a2 ... am, and the sum of these values ​​is multiplied by the measurement interval (s) to calculate the sum d of the solar radiation above the light compensation point as a reference value; d=[(a1-b)+(a2-b)+...+(am-b)]*Measurement interval (s) = [c1+c2+...cm]*Measurement interval (s) (However, if ay-b<0, cy (y is an integer between 1 and m) is calculated assuming ay-b=0.) and Comparing the reference value d with the sum D of the amount of solar radiation equal to or higher than the light compensation point of the test sample, and evaluating the rooting state of the test sample; The evaluation method according to claim 1 ,

6. The evaluation method described in claim 5, wherein the test sample is evaluated as having rooted if the sum D of the amount of solar radiation above the light compensation point of the test sample is equal to or greater than a reference value d.

7. An evaluation method as described in claim 5 or 6, in which the rooting culture of the test sample is evaluated as completed when the sum D of the amount of solar radiation above the light compensation point of the test sample is equal to or greater than a reference value d.

8. The evaluation method according to any one of claims 1 to 7, wherein, during rooting culture, irrigation is performed so that the moisture content of the soil is 18 to 35%.

9. During the rooting culture, the temperature of the rooting environment is measured multiple times to obtain measured values ​​E1, E2, ... Ep (p represents the number of measurements and is 2 or more); Calculate the differences F1, F2, . . . Fp by subtracting 5 from E1, E2, . . . Ep according to the following formula, and calculate the sum G of these differences. G=(E1-5)+(E2-5)+...(Ep-5) =F1+F2+...Fp (However, if Fz-5<0, Fz (z is an integer between 1 and p) is calculated assuming Fz-5=0.) and When evaluating the rooting status of the cuttings, the total value G is further referred to as the accumulated temperature; The evaluation method according to any one of claims 1 to 8, further comprising:

10. The evaluation method according to claim 9, wherein the test sample is evaluated as having roots when the total value G is 800°C or more.

11. The evaluation method according to claim 9, wherein the rooting culture of the test sample is evaluated as completed when the total value G is 800°C or more.

12. The evaluation method according to claim 9, wherein the rooting culture of the test sample is evaluated as completed when the total value G is 800 to 1600°C.

13. The reference for the accumulated temperature is Rooting a cutting of a plant of the same species as the test sample as a reference sample under light irradiation until the cutting takes root; During the rooting culture, the temperature of the rooting environment is measured multiple times to obtain measured values ​​e1, e2, ... eq (q represents the number of measurements and is 2 or more); Calculate the differences (f1, f2, ... fq) by subtracting the reference temperature of 5 ° C. from each of the following formulas, and calculate the sum g of these differences. g=(e1-5)+(e2-5)+...(eq-5) =f1+f2+...fq (However, if fw-5<0, fw (w is an integer between 1 and q) is calculated as fw-5=0.) Comparing the reference value g with the accumulated temperature G for the test sample to evaluate the rooting state of the test sample; The evaluation method according to claim 9 .

14. 14. The evaluation method according to claim 1, wherein the plant is selected from the group consisting of plants of the genus Cryptomeria japonica, plants of the genus Chamaecyparis obtusa, plants of the genus Pinus, plants of the genus Larix, plants of the genus Abies, and plants of the genus Eucalyptus.

15. Rooting a cutting of a plant under light irradiation; and Evaluating the rooting state of the cutting as a test sample by the evaluation method according to any one of claims 1 to 14.

16. A method for producing a plant cutting, comprising:

16. The production method according to claim 15, wherein after the rooting culture is evaluated as being completed by the evaluation method according to any one of claims 1 to 14, a seedling raising step is performed.

17. The method according to claim 15 or 16, wherein, during rooting culture, irrigation is performed so that the moisture content of the culture soil is 18 to 35%.

18. The method according to any one of claims 15 to 17, wherein a seedling growth promotion treatment is carried out in the seedling growth step.

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