JP6896252B2 - How to grow larch plants - Google Patents

Description

The present invention relates to a method for growing a plant of the genus Larch, and particularly to a method for growing a plant by cuttings using a facility.

Raising seedlings of forest trees for afforestation takes a long time of one to two years. The management during raising seedlings is generally extensive management such as open field cutting performed in the open field. In the Larix, except that Larix gmelinii × larch of hybrids that have been developed in Hokkaido "Larix gmelinii hybrid F _1" is being performed cuttings with a simple vinyl house, seedling production by seedlings is common.
Larix gmelin hybrid F ₁ is an excellent variety having both rat resistance and high growth potential. Larix gmelinii hybrids F _1, it is necessary to cross the larch for specific Larix gmelinii varieties Currently, in Hokkaido are underway seed orchard maintenance, the time being, because the seed is a chronic shortage state, the current cuttings It is propagated in. In this breeding method,
(A) Raising rootstocks (b) Harvesting from grown rootstocks (c) Cuttings of harvested ears (d) Sufficiently after each step of raising seedlings of cuttings (seedlings) The grown seedlings are subject to shipping (mountain out).

The growth Larix gmelinii hybrids F _1, a method of using a plastic greenhouse is also performed (Non-Patent Documents 1, 2 and 3). A large-scale facility-based breeding method has been put into practical use overseas (Non-Patent Document 4).
Patent Document 1 describes a method for growing Abies sachalinensis having a peculiar trait and its graft.

Japanese Patent No. 3783129 Japanese Unexamined Patent Publication No. 2016-165302

"Guide for breeding cuttings from F1 seedlings of Larix gmelin", Hokkaido Forest Seedling Cooperative, Hokkaido Forestry Experiment Station (January 2002) "Larix Gmelin F1 Seedling Propagation Method", Ryo Kuromaru and Kazuto Kurita, Hokkaido Forestry Research Institute Research Report No. 40 (March 2003) "Guide for Growing Cuttings", Forest Maintenance Division, Fisheries and Forestry Department, Hokkaido, Forest Resources Department, Forestry Experiment Station, Hokkaido Research Organization (May 2011) “Saint-Modeste Nursery”, Denise Tousignant et. Al, Larix 2007-International Symposium of the IUFRO Working Group S2.02.07

Seedlings Larix plants such Larix gmelinii hybrids F ₁ has been grown, produced cuttings as described above, the supply of seedlings in current in the state of chronic short supply not reach far demand.
The cause of the shortage of seedlings was thought to be due to the current breeding method.
(I) The amount of ears obtained from the growth of the rootstock for ear collection (steps a to b above) is small, and (ii) the cuttings (seedlings) grow normally by raising seedlings. The rate of seedlings (seedling rate) is low. That is, the amount of seedlings produced per unit time (year) as a result of the number of ears that can be cut and the ratio of ears that grow normally per unit time (for example, one year) is the above (i). And (ii), it was considered to be small.

In Larix gmelinii hybrid F _1, nursery of cuttings have been ear (seedlings) are, where you are starting from being cuttings around usually May to July, the growth of the first year in the current technology is up to at most rooting , It will be possible to sapling after the fall of the second year (Non-Patent Document 1). In addition, there is no method for promoting growth after rooting.
The present inventors have further found that not only the production of ears per unit time (year) is small, but also there may be a problem in the method of raising seedlings after cutting.

Regarding the causes and reasons for the shortage of seedlings (i) and (ii) above, there are the following circumstances (when the seedlings are sown the previous year and used as a rootstock for cuttings, the "second grader stand" It is called "tree", and when it is sown in the current year of cutting and used as a rootstock for cuttings, it is called "first grade rootstock"):
(I) About small amount of ear collection Currently, seedling producers in Hokkaido are raising seedlings and using the distributed first-year seedlings as rootstocks, but the number of ear collections is as small as 10 to 15 trees / rootstock. .. The cause is that the seedlings distributed are small, and the rootstocks after the third grade cannot be harvested due to the decrease in rooting rate and the problem of branching.

(Ii) Low seedling yield rate Cuttings in Hokkaido are carried out from May to July when the temperature rises, and strict environmental control is required for rooting, which imposes a heavy management burden on producers and further. Due to a management error, the cuttings are killed and the seedling rate is greatly reduced.

As described above, in the production of rooted cuttings of Larix plants comprising Larix gmelinii hybrids F _1, to provide a technique for supplying cuttings to improve a situation far short demand is quickly resolved It was considered to be a new issue to be addressed.
Therefore, establishing a technique for increasing the amount of ear collection, a technique for improving the seedling yield rate, and / or a technique for promoting the growth of seedlings after rooting is to establish cuttings of larch plants. There is an urgent need in the production of seedlings.

As a result of intensive studies to solve the above problems, the present inventors promote or improve the growth of seedlings by providing an environment that favors a specific physiology of larch plants, and / or We have found that it is possible to increase the number of ears obtained from the rootstock, and as a result of further research, we have completed the present invention.

That is, the present invention relates to at least the following inventions:
[1] A method for growing a larch plant, which carries out at least one of the following steps (1) and (2):
(1) A process of raising seedlings of larch plants in an artificial light environment;
And (2) Larch rootstocks are cultivated for long days of 15 hours or more from the 1st grade and under heating conditions of 13 ° C or higher, and harvested for cuttings during the 1st and 2nd grades. A step of cutting the ears and cutting the harvested ears.
[2] The method of the above [1], which comprises the step (1).
[3] The method of the above [2] in which the step (1) is carried out from the cutting to 2 months [4] The method of the above [2] in which the step (1) is carried out at a temperature of 15 to 25 ° C. and a day length of 12 hours or more. ..
[5] The method of the above [2] or [3], wherein the cuttings are transplanted before the cuttings of the larch plant after rooting are raised.
[6] Including step (2)
(2-A) In the 1st grade, warming at 13 ° C or higher and long-day treatment for 15 hours or longer to collect ears, and then in the 2nd grade, heating at 13 ° C or higher from December to April. Steps of forcibly growing long branches by warm and long-day treatment for 15 hours or more; and / or (2-B) Rootstock growth of larch plants is 12 hours or more day length, temperature 15-25 ° C. The method of [1] above, further comprising a step performed year-round in a closed facility with completely artificial light under the environment of.

According to the present invention, it is possible to solve the conventional problem that the amount of ears collected is small and / or the problem that the seedling yield rate is low. Therefore, according to the present invention, a higher growth rate of larch plants can be achieved, and high-efficiency production of seedlings of larch plants becomes possible.
More specifically, according to the present invention, not only can a larger amount of ears be collected, but also seedlings that have grown the ears within the year in which the ears are cut can be targeted for mountain planting. Therefore, the effect of being able to produce a large amount of seedlings one year earlier than the conventional method, which enables the mountain climbing for the first time in the second grade, is achieved.

The method of the present invention is a method for growing larch plants, which mainly uses facilities to control the day length and temperature. Cultivation of blueberries and the like using a plant cultivation system is known (Patent Document 2). However, it has never been used to use a plant cultivation system in a facility where the environment is controlled for the growth of larch plants, and the effect of the present invention is a special effect that cannot be predicted from the prior art. is there.

It is a photographic figure which illustrates "sunlight utilization type" and "completely artificial light type" (step (1)-step (2)) in the method of this invention. It is a graph which shows the test result about Example 1 (step (1) and (2)). It is a photographic figure which shows the size of the 1st grade seedling raised by the method of this invention (Example 1) in comparison with the size of a normal 1st grade seedling. The photo on the left is a seedling grown by the method of the present invention, and the photo on the right is an example of a normal annual seedling. It is a photographic figure which shows the cutting in Example 2. The photo on the left shows the growth status on the tray, and the photo on the right shows one seedling after rooting (two months after insertion). It is a photograph which shows the growth of the 2nd grade rootstock by the method of this invention including the step (2A) in comparison with the growth of a normal 2nd grade rootstock (Example 3A, sunlight utilization type). In the center of the photo, the left side of the red and white pole is the rootstock grown by the method of the present invention including long-day treatment, and the right side is an example of the sophomore rootstock grown by the conventional method that has not been treated for long days. .. It is a graph which shows the growth of the rootstock treated for a long day and the conventional rootstock in Example 3A. It is a photograph which shows the growth of the rootstock of the 1st grade by the method of this invention including the step (2A) (Example 3B, sunlight utilization type). It is a photograph which shows the growth of the rootstock of the 1st grade by the method of this invention including the step (2B) (Example 3C, completely artificial light type). The photo on the left is an example of a rootstock about 8 months after sowing, and the photo on the right is an example of a rootstock about 1.5 years after sowing. It is a figure which shows the example of the process of the rootstock growth and cuttings growth method of this invention including the step (1)-step (2) ((2-A), (2-B)). FIG. 9 is an enlarged view of a part of a diagram showing an example of the steps of the rootstock growing and cutting growing method of the present invention shown in FIG. 9A. Of the methods of the present invention (“new 1”: “solar utilization facility”) including step (2) (step (2-A)), the part of the step mainly performed in the first year is shown. 9 is another enlarged view of another part of the figure showing an example of the steps of the rootstock growing and cutting growing method of the present invention shown in FIG. 9A. Of the methods of the present invention (“new 1”: “solar utilization facility”) including step (2) (step (2-A)), the part of the step mainly performed in the second year is shown. FIG. 9 is an enlarged view of a part of a diagram showing an example of the steps of the rootstock growing and cutting growing method of the present invention shown in FIG. 9A. The method (“new 2”: “solar utilization facility”) of the present invention including step (2) (step (2-A)) and step (1) is shown. 9 is another enlarged view of another part of the figure showing an example of the steps of the rootstock growing and cutting growing method of the present invention shown in FIG. 9A. The method (“new 3”: closed-type utilization facility) of the present invention including step (2) (step (2-B)) and step (1) is shown. It is a schematic diagram which illustrates the outline of the process and the temporal relationship between the process about the process (1)-(2) in the method of this invention.

The method of the present invention is a method for growing a larch plant, which carries out at least one of the following steps (1) and (2):
(1) A process of raising seedlings of larch plants in an artificial light environment;
And (2) Larch rootstocks are cultivated for long days of 15 hours or more from the 1st grade and under heating conditions of 13 ° C or higher, and harvested for cuttings during the 1st and / or 2nd grades. A step of cutting the ears and cutting the harvested ears.

The steps (1) and (2) will be described below. The outline of steps (1) and (2) and the mutual relationship with each other in terms of time are illustrated in FIG. 10 by a schematic diagram.
Process (1)
The step (1) is a step of raising seedlings of larch plants in an environment of artificial light. Examples of the day length and temperature when raising seedlings of larch plants in the same step include a day length of 12 hours or more and a temperature of 20 to 25 ° C. By this process, the seedlings of larch seedlings after rooting are raised with higher efficiency. By using this process, it is possible to carry out mountain climbing in the year when the cuttings were made. Therefore, the method of the present invention including the step (1) is preferable because it enables highly efficient production of seedlings of larch plants.

The time when step (1) is started, that is, the time when the seedlings of larch seedlings after rooting are started in the environment of artificial light is from February to March, and the seedlings are continued after that. To. Step (1) is performed in a facility such as a greenhouse where light conditions and temperature conditions are controlled.
The day length is preferably 13 hours or more, and more preferably 14 hours or more.

In step (1), it is preferable that rooting is carried out in an environment in which light conditions and temperature conditions are controlled, particularly in an environment in which automatic control is performed.
It is also preferable that the cuttings are transplanted after rooting and before the cuttings of larch plants are raised. This is because the growth of seedlings can be promoted by transplanting to a pot or the like containing a larger amount of medium.

As an environment that satisfies the light conditions in step (1), an environment that uses sunlight in addition to artificial light (hereinafter sometimes referred to as "sunlight utilization type" (Fig. 1, left figure)) or sunlight is used. Instead, any environment in which only artificial light is used (hereinafter sometimes referred to as "completely artificial light type" (Fig. 1, right figure)) can be used.

The method of the present invention in which the control of the light condition and the temperature condition in the step (1) is automatically performed is preferable because the control is performed more reliably. In this case, the type of light source used to give light conditions is not limited, and is an incandescent lamp, a fluorescent lamp, a high-intensity discharge lamp (halogen lamp, high-pressure sodium lamp), or a solid-state light emitting light source (LED, organic EL, etc.). You can.
In the step (1), it is preferable to grow the cuttings at the rooting / seedling stage using a small-capacity (10 ml to 30 ml) plug because mass production in a small area becomes possible. It is more preferable to carry out step (1) in a closed environment system because year-round production becomes possible.
It should be noted that raising seedlings using a small-capacity plug has not been known so far for cuttings of trees, and was carried out for the first time in the present invention. By using a small-capacity plug, high-density production equivalent to 3 to 20 times that of a normal container becomes possible.

Among the methods of the present invention, a method in which the seedling yield rate in step (1) is 80% or more is preferable, a method in which 90% or more is more preferable, and a method in which 95% or more is more preferable. The method of the present invention in which the step (1) is carried out up to 2 months after the cutting is preferable, and the method in which the step (1) is carried out up to 3 months after the cutting is more preferable.

Process (2)
Step (2) is for growing rootstocks of larch plants under long days of 15 hours or more from the first grade and heating conditions of 13 ° C or higher, and for cuttings during the first and second grades. This is a step of collecting the ears of the ears and cutting the collected ears.
The step (2) is different from the step (1) in that the rootstock grows more appropriately, the number of ears generated on the rootstock is increased, and the number of ears collected is increased. It is preferable to carry out the step (2) in combination with the step (1) because the productivity of the cutting ears can be further improved.

In step (2). As a long-day condition, a day length of 16 hours or more is desirable, and a day length of 18 hours is more preferable.
The environment that satisfies the light conditions in the step (2) may be either a sunlight utilization type or a completely artificial light type.

Step (2) includes a step further including the following two steps:
(2-A) In the 1st grade, the ears are collected by heating at 13 ° C or higher and 15 hours or longer for long days, and in the 2nd grade, heating at 13 ° C or higher and from December to April. Step of forcibly growing long branches by long-day treatment for 15 hours or more; and / or (2-B) Seeds of larch plants are sown in pots, 12 hours or more day length after germination, temperature 20- A process of raising seedlings with completely artificial light in an environment of 25 ° C on an annual basis to obtain rootstocks.

The step (2-A) is preferable because the growth of the rootstock is more preferred and the number of ears is further increased.
In the step (2-A), it is preferable to collect the apical buds and / or the side branches because the number of ears is further increased. The time for harvesting is exemplified from May to July for the 1st grade rootstock and May to July for the 2nd grade rootstock.

Step (2-B) is a step of obtaining the rootstock from sowing. Since the rootstock is grown by completely artificial light, it is excellent in optimizing the growth of the rootstock, and according to the step (2-B), the rootstock with uniform growth can be efficiently produced.
In step (2-B), it is preferable to transplant the germinated seedlings into a pot or container having a larger capacity because the number of ears collected is further increased. The period from immediately after germination to 2 months after germination is exemplified as the time for transplanting into the pot.
In step (2-B), it is preferable to cut the stem. For example, the number of ears can be further increased by appropriately cutting the stems when the seedling length is 10 cm or more and 30 cm or less, and the long branches suitable for ear collection are appropriately extended to about 5 cm suitable for ear collection.

Among the methods of the present invention, a step of raising seedlings of larch plant cuttings in an environment with a day length of 12 hours or more and a temperature of 20 to 25 ° C. (hereinafter sometimes referred to as "step (3)") is further performed. Those containing are preferable. This is because the seedlings of larch seedlings after rooting by the same process are raised with higher efficiency. By using this process, it becomes more reliable to carry out mountain climbing in the year when the cuttings were made. Therefore, the method of the present invention including the step (3) is preferable because it enables highly efficient production of seedlings of larch plants.

The time when step (3) is started, that is, the time when the raising of cuttings of larch plants after rooting is started in an environment with a day length of 12 hours or more and a temperature of 20 to 25 ° C is from February. It is March, after which seedlings will continue to be raised. Step (3) is performed in a facility such as a greenhouse where light conditions and temperature conditions are controlled.
The day length in the step (3) is preferably 13 hours or more, and more preferably 14 hours or more.

The method of the present invention does not necessarily require fertilizer as in the conventional method, but the method of the present invention performed under the condition that fertilizer is used is preferable.
The type of fertilizer is not limited, and both solid fertilizer and liquid fertilizer are preferably used. The solid fertilizer may be mixed with a fertilizer-adjusted fertilizer in which the initial fertilizer effect is suppressed in advance in the medium, or may be added at the time of shifting to the time of root elongation. Liquid fertilizer may be added to the medium after the step of root elongation.

In the present invention, by appropriately combining steps (1) and (2), it is possible to grow a larch plant corresponding to a target growth rate and environmental conditions under which existing equipment can be controlled.
Examples of combinations of steps (1) and (2) are shown in FIGS. 9A to 9D.
Two methods, "solar-powered facility A" and "solar-powered facility B," are shown as a combination method using solar-powered facilities.
In the method of "solar utilization facility A" (Fig. 9A, Fig. 9B-1 and Fig. 9B-2), the process (2-A) for growing the rootstock is continued until the second year after sowing, and the cuttings are grown. Is carried out from the first year by a known method or a method including step (3). According to this method, the ears are supplied from the first year after sowing, and the cuttings are directly placed in a pot filled with a special medium.
In the method of "solar utilization facility B" (Fig. 9A and Fig. 9C), the process (2-A) for growing the rootstock is continued until the second year after sowing, and the cuttings are grown for the first to second years. It is carried out by cutting seedlings by a known method or a method including step (3), or by step (1) from the second year. According to this method, the seedling production time can be shortened by raising the rooted seedlings at the time when the amount of sunlight is the highest.

When using the "closed facility use" method (Fig. 9A and Fig. 9D) in which the environmental conditions are completely controlled, the rootstock is sown multiple times at intervals of about 3 months according to step (2-B). It is cultivated. The growing of cuttings seedlings by a plug is carried out by the step (1), and the growing after transplanting the seedlings is carried out by a known method or a method including the step (3). According to this method, the production of ears is further increased, so that a larger amount and more efficient growth is possible.

The present invention will be described in more detail by way of examples, but these examples do not limit the present invention in any sense.

＜試験結果・考察＞
結果を図２に示した。挿し木の生育は台木ごとに集計した。
発根後、ある程度生育した段階（挿し付け後２ヶ月）で通常の温室へ移動したところ、挿し付け後235日目（2016年10月25日）には、苗長は35〜45cmと山出し可能な大きさに成長した。この大きさは通常の２年生苗の生長とほぼ同等であった（図３）。工程（１）を含む本発明の方法による挿し木苗の製造効率が高いことが確認された。
なお、発根までは自動環境制御下において生育を行ったため管理にほとんど手間はかからなかったにもかかわらず、得苗率は100％であった。通常、温室で挿し木育苗する場合には、日射、温度、湿度をきめ細かに管理しなくてはならない手間及び低い得苗率と比較すると、本発明の方法として工程（１）を含む方法によればはるかに効率的に発根苗を生産できることも明らかになった。 ● Example 1
<Purpose> To confirm the production efficiency of cuttings by the method of the present invention including the step (1).
<Test method>
・ Container / seedling raising method, etc. Table 1 below.

<Test results / discussion>
The results are shown in FIG. The growth of cuttings was tabulated for each rootstock.
After rooting, when it grew to some extent (2 months after insertion), it was moved to a normal greenhouse, and on the 235th day after insertion (October 25, 2016), the seedling length was 35 to 45 cm. It has grown to the size possible. This size was almost the same as the growth of normal second-year seedlings (Fig. 3). It was confirmed that the production efficiency of cuttings by the method of the present invention including the step (1) was high.
The seedling yield rate was 100%, although it took little time to manage because it grew under automatic environmental control until rooting. Normally, when raising seedlings for cuttings in a greenhouse, the method including step (1) as the method of the present invention is compared with the labor and low seedling yield rate, which requires fine control of solar radiation, temperature, and humidity. It was also revealed that rooted seedlings can be produced much more efficiently.

● Example 2
<Purpose> To confirm the production efficiency of cuttings by the method of the present invention including the step (1).
<Test method>
-The cuttings were cultivated at the rooting and seedling stages using a small-capacity (30 ml) plug.
-As a plug, "Ellepot" (φ30mm x H30mm manufactured by Ellegard) was used.
-Completely artificial light type seedlings were raised under the conditions of 12 hours day length and 25 ° C.

<Test results / discussion>
As a seedling yield rate after 2 months of cutting, a seedling yield rate of 90% or more was achieved (Fig. 4). This seedling yield rate far exceeds the seedling yield rate (the rate at which rooting and transplantation is possible) in the prior art, which is about 70% or less. In addition, the pot is contained in degradable paper, and the elongated roots are sufficiently air-cut and can be directly transplanted to a seedling raising pot or container.

● Example 3A
<Purpose> As the method of the present invention including the step (2), the production efficiency of cuttings and seedlings by the method of the present invention including the step (2-A) is confirmed.
<Test method>
・ Venue: Experimental greenhouse in Hokkaido Forestry Experiment Station (Bibai City, Hokkaido)
-Rootstock: Second graders sown and cultivated in a container with side slits (HIKO-120SS manufactured by BCC) in April 2013 were used. It was transplanted to a polypot with a diameter of 15 cm and a depth of 12.5 cm on April 18, 2014. The medium was 70% peat moss + 30% Kanuma soil.
-Growth environment: The greenhouse was controlled at a minimum temperature of 13 ° C until May 20 (using sunlight), and when the temperature inside the greenhouse reached 25 ° C or higher, the ventilation window was opened for cultivation.
・ Long-day processing: From August 4th to October 31st, 2014, the day length was set to 18 hours. The irradiation time was from 2:00 am to sufficiently bright after sunrise (adjusted according to the season) and from sufficiently bright before sunset to 8:00 pm. A high-pressure sodium lamp (360W, manufactured by Iwasaki Electric Co., Ltd., product number NH360FLS) was used as the light for irradiation.
-As a control conventional rootstock, seedlings were sown in a seedling field in April 2013, transplanted to the same pot on April 18, 2014, and grown under the same conditions except for natural light.
<Test results / discussion>
The results at the end of October, when the long-day processing was completed, are shown in FIGS. 5 and 6. The rootstock grew to over 1 m (Fig. 5, 5 on the left) and far exceeded the rootstock by the prior art (Fig. 5, 5 on the right) (Fig. 6). The number of ears was also significantly increased by the method of the present invention.

● Example 3B
<Purpose> As the method of the present invention including the step (2), the production efficiency of cuttings by the method of the present invention including the step (2-A) is confirmed by a test different from that of Example 3A.
<Test method>
・ Venue: Experimental greenhouse in Hokkaido Forestry Experiment Station (Bibai City, Hokkaido)
・ Rootstock: Sown in a ribbed container (JFA300 manufactured by the National Federation of Forest Seedling Cooperatives) on March 6, 2015. On March 10, 2016, it was transplanted to a polypot with a diameter of 15 cm and a depth of 15 cm. The medium was 100% peat moss for the ribbed container and 70% peat moss + 30% Kanuma soil for the polypot.
・ Growing environment: In the greenhouse (using sunlight), the temperature was controlled from March 6th to April 27th in 2015, and from March 10th to May 7th in 2015 at a minimum temperature of 13 ℃. In addition, when the temperature inside the greenhouse reached 25 ° C or higher, the ventilation window was opened for cultivation.
・ Long-day processing:
March 6-May 23, 2015, July 31-September 30, 2016 March 10-May 21, July 21-18 hours long until the cuttings are finished .. The irradiation time was sufficiently bright before sunset from 2:00 am until it became sufficiently bright after sunrise (adjusted according to the season). A high-pressure sodium lamp (360W, manufactured by Iwasaki Electric Co., Ltd., product number NH360FLS) was used as the light for irradiation.
<Test results / discussion>
Table 2 shows the number of ears collected with and without long-day treatment and with and without pruning the spindle in the first year. It grew to a size that allows ear collection in the first grade (Fig. 7), and the amount of ear collection in the first grade increased by 20 to 40% by long-day treatment (Table 2). In addition, pruning the main spindle at the 1st grade reduced the amount of ears collected at the 1st grade, but increased the amount of ears collected up to the 2nd grade by 10% or more.
Furthermore, by the second grade, 70 trees / rootstock or more were achieved.

● Example 3C
<Purpose> As the method of the present invention including the step (2), the production efficiency of cuttings and seedlings by the method of the present invention including the step (2-B) is confirmed.
<Test method>
・ Target: Clean Larch ・ Sowing date: June 19, 2015. After germination, it was transplanted into a pot having a capacity of 200 ml, and on December 18, the same year, it was transplanted into a pot having a capacity of 1 liter.
・ The stem was cut at a seedling length of 30 cm.
・ Growing environment: 18 hours day length, temperature 25 ° C, bottom liquid was irrigated daily. The medium was peat moss: vermiculite: Kanuma soil = 40: 40: 20% v / v with the same composition in the above pots and pots. The conditions of the added fertilizer and the composition of the fertilizer are as shown in Table 3. Three bottles are provided for each of the sections where the added fertilizer condition is HC085: 10 g / L and the fertilizer composition is OSM 10 g / L, and the additive fertilizer condition is OSM 10 g / L and the fertilizer combination is OSM 10 g / L. The number of ears that could be collected was examined as the number of ears collected. The earing time was from February to September 2016.

<Test results / discussion>
The results are shown in Table 3. In each ward, it was possible to collect ears that exceeded the conventional technique.
The fertilizer condition was HC085: 10 g / L, and the fertilizer composition was slightly better in the OSM 10 g / L plot, and 48 spikes could be harvested from the most rootstock.
The state of the ears is shown in FIG.

From the above results, it was clarified that the method of the present invention can achieve a higher growth rate than the prior art for plants of the genus Larch.

According to the present invention, a higher growth rate of larch plants can be achieved, and highly efficient production of seedlings of larch plants becomes possible. Therefore, the present invention greatly contributes to the development of the larch plant cutting seedling production industry and related industries.

Claims (7)

Proliferation method of larch plants according to the following step (1):
(1) A step of raising seedlings of larch plants at a temperature of 20 to 25 ° C. and a day length of 12 hours or more in an artificial light environment. The method according to claim 1 , wherein step (1) is carried out from cutting to 2 months. The method according to claim 1 or 2 , wherein the rooted cuttings are transplanted to another medium before the rooted larch seedlings are raised. How to grow Larch plants, including the following steps:
(2) Larch rootstocks are cultivated under long days of 15 hours or more and heating conditions of 13 ° C or higher from the 1st grade, and earing for cuttings is performed during the 1st and 2nd grades. And the step of cutting the harvested ears, and (2-A) 1st grade, warming at 13 ° C or higher and long-day treatment for 15 hours or longer to harvest the ears, and then 2nd grade. Steps of forcibly elongating long branches by heating at 13 ° C. or higher and long-day treatment for 15 hours or longer from December to April; and / or (2-B) Larch plant stand wood fostering, photoperiod 12 hours or more, in an environment of temperature 15-25 ° C., the step to be within the anniversary effected facilities by total artificial light. Including step (2-A)
The method of claim 4, further comprising harvesting apical buds and / or side branches. Including step (2-B)
Seeds of larch plants are sown, and after germination of the seeds, seedlings germinated from the seeds are transplanted into larger pots or containers to grow rootstocks and / or.
The method according to claim 4, further comprising cutting the rootstock in the middle of growing. A method for growing a larch plant, which comprises the step (1) according to claim 1 and the step (2) according to claim 4.

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