JPH09149729A - Raising of plant seedling - Google Patents

Abstract

PROBLEM TO BE SOLVED: To enable high-quality seedlings to be produced more efficiently through enabling healthy seedlings with solid basal portion to be raised, by replenishing far-infrared rays with the light-emitting wavelengths within a specified range only within a specified period after germination in the plant seedling raising stage. SOLUTION: In the seedling raising stage for a plant such as Brassica campestris, far-infrared or infrared rays with the light-emitting wavelengths of 670-950 (pref. 690-950) nm are replenished by e.g. a light-emitting diode only within 10 (pref. 6) days after germination. It is preferable that the intensity of the rays be >=100μW/cm<2> .

Description

Detailed Description of the Invention

[0001]

The present invention has an emission wavelength of 670.
The present invention relates to a method for growing healthy seedlings using far-red light or infrared light of 950 nm.

[0002]

2. Description of the Related Art In recent years, in order to grow plants, especially vegetables and flowers, stably and irrespective of the weather, it has been attempted to carry out facility cultivation in which the growth environment is artificially controlled using an artificial light source. Department, has been put to practical use. As the artificial light source, a high pressure sodium lamp, a metal halide lamp, a fluorescent lamp, an incandescent lamp, etc. are used. It has also been proposed to use a light emitting diode or a semiconductor laser as the light source.
(JP-A-4-121117 and JP-A-5-115219) Similar light sources are used for supplementing light at the seedling raising stage, but these are intended to supplement the light energy for photosynthesis, and to photosynthesis. No attempt has been made to grow healthy seedlings by supplementing far-red light or infrared light that does not contribute.

In institutional cultivation using artificial light sources, research has been conducted on the relationship between the growth of plants and the wavelength of light to be irradiated. Red light is mainly for photosynthesis, blue light is mainly for phototropism, and far-red light is for far infrared light. Are said to be mainly involved in flower bud formation. Further, far-red light is known to have a germination-inhibiting action and a stem-elongating action on certain plants. However, for far-red light and infrared light,
It has not been confirmed so far that it has an internode shortening action and a healthy seedling raising action as shown in the present invention.

[0004]

[Problems to be Solved by the Invention] In recent years, seedling production and cultivation are often carried out in different places, and farmers purchase cell-molded seedlings from companies specialized in raising seedlings. . A nursery company is required to grow healthy seedlings that are not oversized, that is, have no internode growth. Seedlings with short internodes and a solid base grow well after planting, and if they support the above-ground part well, they have a good light-receiving condition and are less susceptible to disease. In addition, as the word "half-seedling" is used, good and bad seedlings have a great influence on the growth of subsequent crops. Therefore, healthy seedling raising is not limited to seedling raising companies but to all farmers.

The inventors of the present invention are said to be ineffective in photosynthesis, and conversely have an action of extending stems and petioles, and have an emission wavelength of 670 to 950 nm which has an action of suppressing germination.
Far-red light or infrared light can be prevented at the seedling raising stage, especially only for a few days immediately after germination, to prevent overgrowth and suppress the elongation of the stem (hypocotyl), and thus to grow healthy seedlings. That is, the present invention has been accomplished.

[0006]

The object of the present invention is to provide a plant whose supplemental wavelength is far-red light or infrared light having an emission wavelength of 670 to 950 nm only within 10 days after germination at the seedling raising stage of the plant. Achieved by raising seedlings. Examples of the light source used in the present invention include optical semiconductors, particularly light emitting diodes (LEDs), semiconductor lasers, fluorescent lamps, and the like, and light emitting diodes are particularly preferable for obtaining the effects of the present invention. Then, far-red light or infrared light having an emission peak wavelength of 670 to 950 nm, preferably 690 to 950 nm is irradiated. Since the far-red light or infrared light of the present invention is used as supplementary light, it can be used in combination with other artificial light or sunlight irradiation, but the light intensity of far-red light or infrared light is 100 μW / It is preferable to irradiate with light of cm ² or more. Further, it is preferable that the intensity of light having an emission wavelength of 670 to 950 nm is half or more that of light having an emission wavelength of less than 670 nm.

The method for raising seedlings of the plant is not particularly limited, and it is suitable for supplementing light under artificial light control immediately after germination, but it is also possible for raising seedlings under sunlight. For example, seeds are sown in a cell forming tray filled with culture soil, and immediately after germination, far-red light or infrared light having an emission wavelength of 670 to 950 nm is irradiated. In the case of hydroponics, the same light irradiation treatment is performed after germination on a sponge cube.

In the present invention, "only within 10 days after germination" means that light irradiation treatment is performed within 10 days after germination, preferably within 6 days, preferably for 6 hours or longer, and after that period. Means that supplementation is not continued by irradiation with far-red light or infrared light of 670 to 950 nm. This is because if continued after that, it may cause lengthening symptoms such as internodal elongation. Incidentally, for the supplementation start time, a plant that germinates even with far-red light or infrared light, for example, for plants of the family Brassicaceae, such as broccoli, may be subjected to light irradiation treatment before germination, far-red light or infrared light. For plants that do not germinate under light, for example, plants of the Asteraceae family such as lettuce, light irradiation treatment is performed after germination. The definition of “only within 10 days after germination” of the present invention includes a mode in which light supplementation is started before germination or after germination. According to the above-mentioned plant raising method, the emission wavelength is 670 to 950.
By irradiating with far-infrared light or infrared light having a wavelength of nm, a seedling having a short hypocotyl, that is, a short seedling can be raised.

[0009]

【Example】

(Example 1) After germination of komatsuna under white light (1 day later), white, blue, yellow, orange, red, red + far red,
Seedlings were cultivated under far-red light irradiation and in the dark (25 ° C., 4 days), and the hypocotyl length was compared. The far-red light source is a light emitting diode (1000 μW / cm ² ), and the other light sources are fluorescent lamps (2
000 lux) was used. As a result, the hypocotyl was the shortest in the far-red light irradiation group, and then in the red + far-red light irradiation group (Table 1). The seedlings irradiated with far-red light or red + far-red light have the lowest length and are healthy seedlings with a firm base, and good growth can be expected thereafter.

[0010]

[Table 1]

(Example 2) After lettuce was germinated under irradiation of white light (2 days later), seedlings were grown for 2 days under irradiation of white light + far-red light, and the hypocotyl length was measured. As a control test, lettuce was sown and bred under white light irradiation or white light + far-red light irradiation, and the hypocotyl length was compared 4 days later. The white light source is a fluorescent lamp (2
700 lux), the far red light source is a light emitting diode (100
0 μW / cm ² ) was used and cultivation was performed at 25 ° C. As a result, after germination, by adding far-red light, the hypocotyl length was shortened as compared with the case where it was not added. On the other hand, it did not germinate when irradiated with far-red light from the time of sowing. (Table 2).
This result shows that even in the case of a normal seedling raising method, by adding and supplementing far-red light immediately after germination, it is possible to raise healthy seedlings of lesser length than before, and thus seedlings were raised by this method. The seedlings can be expected to grow well thereafter.

[0012]

[Table 2]

(Example 3) Broccoli was irradiated with white light,
Alternatively, the seedlings were sown and raised under irradiation of white light + far-red light, and after 8 days, the hypocotyl length was measured. The white light source is a fluorescent lamp (2700 lux), and the far-red light source is a light emitting diode (1000 μW / c).
m ² ) was used and cultivation was carried out at 25 ° C. As a result, germination occurred even under light containing far-red light, and the hypocotyl length was shortened by irradiation with far-red light (Table 3). This result also shows that, as in Example 2, even in the case of the normal seedling raising method, by adding the far-red light as a supplement, it is possible to grow healthy seedlings having a shorter length than before. It also shows that some plants can emit far-red light from the time of sowing.

[0014]

[Table 3]

[0015]

INDUSTRIAL APPLICABILITY As described above, according to the present invention, by supplementing far-red light or infrared light having an emission wavelength of 670 to 950 nm at the seedling raising stage of a plant, the base of the seedling is enhanced without being overpowered. It is possible to grow healthy seedlings, and by introducing this technology into an existing seedling production system, it is possible to more efficiently produce high-quality seedlings.

Claims (1)

[Claims] 1. A method for raising seedlings of a plant, which comprises supplementing far-red light or infrared light having an emission wavelength of 670 to 950 nm only within 10 days after germination at the stage of raising seedlings of the plant.