This paper introduces the Research Center for Intelligent Greenhouse Systems supported by the Ministry of Economy, Trade and Industry (METI) and the Demonstration and Training Center for Greenhouse Agricultural Production supported by the Ministry of Agriculture, Forestry and Fisheries (MAFF). These centers are managed by Ehime University where the plant factory based on the speaking plant approach (SPA) is studied. The programs of training for plant factory are developed and practiced.

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This paper introduces the plant factory research center in Osaka Prefecture University. First, the background of the plant factory center development project is explained. Then, the research subjects, organization, facility, and function of the R&D center for plant fac-tory of Osaka Prefecture University are explained in detail. Furthermore, activities of the human resource development, training, and research are also reported followed by the inquiry contact.

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We examined the possibility of using of light emitting diodes (LEDs) as a covering cul-ture to improve tea leaf quality. We investigated the effects of red, blue, and white LED irradiation at 100 μmol m^-2 s^-1 PPFD on the growth, photomorphogenesis, photosynthesis, and nitrogen assimilation of young tea plants grown in hydroponic culture. After 15 days of light treatment, we saw increases in stomatal conductance, photosynthetic rates, transpi-ration rates, and soluble sugar content of new leaves in plants given a blue or white LED treatment, compared to the red LED treatment. No difference was seen in the increments in fresh weight of new leaves among the three LED treatments. Glutamine synthetase ac-tivities in rootlets were lower in plants in the red LED treatment than in the other two LED treatments. The rate of nitrogen translocation to new leaves was also the lowest in the red LED treatment. These findings suggested that irradiation with light containing blue wavelengths may be effective at improving the quality of tea plants, although no difference was seen in increments of fresh weight of new leaves in response to light quality under low light intensity.

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The effect of light quality on the growth of lettuce (Lactuca sativa L.) was investigated for cultivation in a plant factory. In this study, we used a mixture of red, green and blue light emitting diodes. The fresh weight of lettuce increased under monochromic red light and a mixture of red and green light. There was no significant difference in the fresh weight of lettuces grown under monochromic red light and those grown under a mixture of red and green light. When a mixture of red and blue light was used, the fresh weight decreased with increase in the ratio of blue light. Stem length decreased and plant shape improved under a mixture of red and blue light. There was no significant difference in the stem length of lettuces grown under monochromic red light and those grown under a mixture of red and green light. Generally, blue light is required to improve plant shape. However, in the case of “Chima sanchu”, which is one of the varieties of lettuce used in this experiment, stem elongation under monochromic red light and that under a mixture of red and green light were acceptable in comparison with that observed lettuces grown outdoors. Energy consumption was the lowest under monochromic red light. These results suggested that monochromic red light was suitable for the cultivation of lettuce.

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From the viewpoint of conservation-oriented agriculture, this study investigated a closed cultivation system using a combination of rice hull substrate and TiO₂ photocatalytic treat-ment of the waste nutrient solution. First, an extract of rice hulls in distilled water was treated with a TiO₂-coated porous alumina filter under ultraviolet light irradiation. Then, rose (Rosa hybrida) rooted cuttings were soaked in the treated extract, untreated extract, or pure nutrient solution. The total weight of the shoot and leaves soaked in the photocatalytically treated extract was heavier than that in the untreated extract, and was similar to that in the pure nutrient solution. Next, rose growth was compared in three practical cultivation systems: two closed systems using rice hull substrate with photocatalytically treated or untreated waste nutrient solution (photocatalytically treated and untreated systems), and an open system using rockwool substrate (current system). The growth and yield in the photocatalytically treated system were significantly greater than those in the untreated system and were comparable to those in the current system. These results show that the TiO₂ photocatalytic treatment of the waste nutrient solution is effective in closed soilless cultivation using rice hull substrate.

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Potato shoots were cultured in vitro under both natural ventilation and airtight vessels. In airtight vessels, ethylene and carbon dioxide accumulated to 0.43 μmol mol^-1 and 6.4%, respectively. Emission of ethylene from shoot cultures was almost no difference between airtight and natural ventilation vessels. It was made clear that ethylene accumulated in airtight vessels without any physiological effects of airtight condition on ethylene produc-tion. The cultured shoots were short inter-nodal length, many axillary shoots and small undeveloped leaves. The change of morphogenetic characteristics was considered the effects of gas composition in airtight vessel.

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[in Japanese]

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