JPS6251935A - Artificial illumination for growing plant - Google Patents

Abstract

(57) [Summary] This bulletin contains application data before electronic filing, so abstract data is not recorded.

Description

DETAILED DESCRIPTION OF THE INVENTION Field of Industrial Application The present invention relates to an artificial lighting method for growing plants using high-pressure sodium wrap as an artificial light source.

Traditional Art Recently, plant factories for the production of vegetables, mainly lettuce and salad greens, are gradually being realized.

This plant (vegetable) generally has maximum photosynthetic sensitivity to light around 650 nm, and 300 to 495 nm.
The sensitivity to light mainly affects morphogenesis such as leaf coloration and shape. Therefore, as an artificial light source, a high-pressure sodium wrap of 660 watts, which has a high spectral energy concentration around 650 nm, is used for photosynthesis, and a mercury lamp, a metal halide lamp, or a fluorescent lamp, which has a high spectral energy concentration of 300 to 495 nm, and which is usually 250 watts, is used for photosynthesis. is used for morphogenesis. These 1!17 ri lamps are installed by determining the lamp load and arrangement of lighting equipment to achieve the optimum spectral energy distribution for plant growth. In general,
Using separate lighting equipment depending on the type and size of the lamp,
Mixed light illumination is applied to the plants so that the illumination distribution is almost uniform.

Problems to be Solved by the Invention Conventional artificial illumination methods for growing plants using mixed light lighting use separate discharge lamps, lighting equipment, and ballasts, and therefore, depending on the type of lamp, There are differences in luminous flux maintenance rate, changes in spectral energy distribution during life, life time, etc., and it is difficult to always maintain uniform illuminance j3 and spectral energy distribution. This caused variations in shape, which was a problem in quality control.

Means for Solving the Problems The present invention uses a single discharge lamp to emit spectral energy for both photosynthesis and morphogenesis in a ratio suitable for plant growth, and is capable of emitting spectral energy for both photosynthesis and morphogenesis in a ratio suitable for plant growth. Provided is an artificial lighting method for growing plants using high-pressure sodium wrap as an artificial light source in which the ratio of spectral energy output between wavelengths of 300 to 495 nm is 6.0% or more and 20% or less with respect to the total spectral energy. It is something to do.

Function Compared to the conventional method of mixed light illumination using different types of discharge lamps, the method according to the present invention is 1! ! For lighting with similar discharge lamps,
It becomes possible to make the spectral energy distribution almost uniform throughout the lifespan, and the variation among individual plants is greatly reduced. In addition, the number of installed discharge lamps, lighting equipment, ballasts, etc. can be halved, and equipment costs and maintenance costs can be significantly reduced. A single discharge lamp can have the functions of photosynthesis and morphogenesis. By doing so, energy can be efficiently released and power consumption can be reduced.

DESCRIPTION OF THE PREFERRED EMBODIMENTS The details of the present invention will be explained below with reference to illustrated embodiments.

FIG. 1 is a longitudinal cross-sectional view of a 360 watt high pressure sodium wrapped arc tube. Arc tube 1 has an inner diameter of 3 mm and a length of 115 mm.
Envelope 2 made of translucent alumina of mm, and ?mm at both ends? [I3.3' was attached by welding, and the electricity introduction body 4.4' made of niobium was attached to the glass solder sealed body 5.5'.
The shape is airtightly sealed. The arc tube 1 is filled with sodium, mercury, and a starting rare gas (not shown).

FIG. 2 is a schematic diagram of the lamp lighting circuit.

The high-pressure sodium wrap 7 in which the arc tube 1 is mounted inside the glass outer bulb 6 is generally turned on by applying a commercial power source 9 of 200V via a ballast 8.

High-pressure sodium-wrapped arc tubes used for general lighting such as roads or factories are designed to have the highest efficiency relative to human specific luminous efficiency. The sodium sealed in the arc tube emits light near the peak of relative luminous efficiency, and mercury plays the role of effectively drawing out the light emission from the sodium. Since mercury itself emits light in a short wavelength range with low relative luminous efficiency, reducing lamp efficiency, the lamp is designed to prevent mercury from emitting light as much as possible. However, unlike general lighting, light sources for growing plants also require radiant energy in a short wavelength range. Therefore, we used an unsaturated vapor type 1 high-pressure sodium wrap that allowed the entire amount of the contents to evaporate, and the amount of sodium and mercury to be sealed in the arc tube.
In other words, we varied the vapor pressure and investigated the relationship between its spectral energy distribution and vegetable growth. The results are shown in the table below and Figure 3.

This result was obtained when salad greens were used as the vegetable.

[Left below] From the table, when illuminated with only high-pressure Natrium 11 lamps,
Compared to Test No. 3, which has the highest lamp luminous flux and is used for general lighting, when test No. 1゜2 has more sodium content and high vapor pressure, 050 n
Although the photosynthetic energy around m increases and the number of plants used increases, the water content is high and the leaves are yellow-green and too soft, so they have little commercial value. Conversely, if you reduce the sodium content and increase the mercury vapor pressure from test No. 0.4 to No. 12, the amount of 1 in the vegetables gradually decreases, but the leaves become darker green and the moisture content of the vegetables becomes smaller and firmer. becomes. This effect becomes noticeable when the amount of sodium encapsulated product is less than 0.035 mg. 300-720nm at this time
300 to 49 for the sum of spectral energies Y- between wavelengths of
The ratio of spectral energy in the short wavelength region of 5 nm (7) is 6.0
% or more. Although it depends on the type of vegetables, in this test, the optimum conditions for the vegetables were to set the spectral energy ratio of test No. 8 to about 8%, which produced the best vegetables. However, as in Test No. 12, when the spectral energy ratio reaches 20%, the weight of the vegetables decreases greatly, and they become hard and small. stomach.

Also, if you increase the illuminance to speed up the growth rate or extend the number of cultivation days, you will only increase the electricity costs and the quality will not be good. Therefore, the ratio of the spectral energy P-ffi between wavelengths of 300 to 4050 m to the sum of spectral energy between wavelengths of 300 to 720 nm needs to be 0.0% or more and 20% or less.

FIG. 3 shows the spectral energy molecules fi of Test No. 3, which is the same as the conventional lamp, and Test No. 8, according to the present invention.

From this figure, test N098 has a wavelength of 650 nm, which is necessary for photosynthesis.
Although the nearby spectral energy decreased relatively significantly compared to Tests No. 3 and 3, the reason there was little difference in the amount of vegetables in spite of this is because the growth of vegetables was promoted by the increase in the spectral energy of short wavelengths. It is believed that there is. In addition, lettuce vegetables were also tested, and similar results were obtained.

In addition, in the above example, a high-pressure sodium wrap was simply used as a light source for growing plants, in which a high ratio of mercury is enclosed in addition to sodium in the arc tube. High pressure sodium wraps are also possible.

Effects of the Invention As detailed above, the method of the present invention is a simple method of increasing the ratio of mercury to sodium sealed in the arc tube of a high-pressure thorium lamp and increasing the spectral energy in the short wavelength range. There is no need for a separate light source for morphogenesis as in the past, and it has excellent effects such as significantly reducing equipment costs, electricity costs, and maintenance costs, as well as stabilizing the quality of plants. be.

[Brief explanation of the drawing]

Fig. 1 is a cross-sectional view of an arc tube of a high-pressure lithium lamp used in the method of the present invention, Fig. 2 is a lamp lighting circuit diagram used in the method of the present invention, and Fig. 3 shows an example of spectral energy distribution according to the method of the present invention using a conventional method. It is a characteristic diagram shown in comparison with a Japanese irises. 1... Arc tube, 7... High pressure sodium filled product 1
Diagram luminescence g Translucent / Notes on the outer surface of the screen, Electrical shield q, Mitsuru m ore source

Claims (1)

[Claims] A high-pressure sodium wrap with a ratio of spectral energy between wavelengths of 300 to 495 nm of 6.0% or more and 20% or less to the total spectral energy between wavelengths of 300 to 720 nm is used as an artificial light source. An artificial lighting method for growing plants.