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Showa Denko’s New Plant Cultivation Method Adopted in Okinawa
LED-Based Lettuce Growth Facility Contributes to 30% Cut in Electricity Cost -

Showa Denko K.K.
Apr 25, 2014

Showa Denko (SDK) (TOKYO:4004) announces that its proprietary LED lighting equipment and high-speed plant growth technology (Shigyo MethodTM) have been adopted by Gushiken Co., Ltd., a major bread maker in Okinawa.  The company, led by President Hisao Gushiken, is headquartered in Uruma City, Okinawa Prefecture.

Shigyo MethodTM, developed jointly by SDK and Yamaguchi University, accelerates the growth of plant at LED-based facilities by irradiating light with optimum wavelengths and intensity in consideration of the kind of plant and growing stages.  SDK provides LED lighting equipment containing proprietary LED chips that emit deep-red light with the wavelengths of 660 nm (optimum light for plant’s photosynthesis) at the world’s highest level of brightness*.  The equipment, which also contains blue LED chips, can easily change the intensity of deep-red and blue light through output adjustments.  The combination of Shigyo MethodTM and the proprietary LED lighting equipment can create the optimum lighting environment for plant growth.

According to the results of a demonstration experiment at Gushiken’s plant growth facility, the electricity cost, including air-conditioning electricity cost, has decreased by more than 30% compared with that of conventional fluorescent-lamp-based facility.  It has also been confirmed that the amount of harvest increases significantly**.  Thus, Gushiken has decided to fully shift from fluorescent-lamp-based lighting to SDK’s technology.

Gushiken is selling lettuce harvested at its plant growth facility to the outside, in addition to using it in sandwiches and other types of bread products.  Okinawa has a high-temperature, humid climate, and is often hit by typhoons.  Thus, it is difficult to grow highland vegetables outdoors, especially in the summer season.  Gushiken renovated part of its old plant in Kitanakagusuku Village into a closed plant growth facility, and started operating the facility in September 2010.  The company’s lettuce is popular as it is grown chemical-free and stable in quality.  The company has therefore expanded the scope of vegetables grown in the facility.

SDK’s LED lighting equipment for plant growth has been adopted at 14 facilities from Hokkaido to Okinawa.  Due to its high efficiency and low heat generation, LED lighting contributes toward reducing electricity cost.  Furthermore, through combination of the LED equipment with Shigyo MethodTM technology, the shipment cycle can be significantly shortened***, resulting in highly profitable operation of a plant growth facility.  We will continue making comprehensive proposals on plant growth facilities, covering the design, cultivation guidance, and maintenance, so that we can contribute toward realizing the sufficient supply of safe food.

Notes:
* As of April 25, 2014
** The demonstration experiment was conducted at a facility with a growing area of 270 m2, which can produce 600 heads of lettuce a day.  Results of cultivation for the same period were compared.
*** In the demonstration experiment, the period from planting to harvest of leaf lettuce has been shortened from 42 days (under fluorescent lamp lighting) to 32 days. However, plant growth depends not only on photo effect but also on many other factors, including temperature, humidity, wind, nutrient solution, and carbon dioxide.Growth conditions and results can also become substantially different depending on the kind of plant and individual plants. While the experiment results suggest the effectiveness of the plant cultivation method proposed by SDK, no guarantee is provided as to actual results.


Gushiken's Plant growth facility


Lettuce supplied by Gushiken to consumers

For further information, contact:
Public Relations Office (Phone: 81-3-5470-3235)