The germination processes in the eggplant seeds are closely correlated with the germination temperature, GA₃ and the physiological conditions of the seeds with ripening and after-ripening. Effects of GA₃on germination in the eggplant seeds can be divided into three functions: a) dormancy releasing effect of the least-ripened and ripened seeds in the dormant stage without after-ripening, b) stimulating effect of the least-ripened seeds in the non-dormant and aged stages, and the ripened seeds in the aged stage, c) the effect of protection to the secondary thermo-dormancy imposed by unfavorable high temper-atures for the germination, and that of germination induction at these high temperatures.

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The actual effects of light fluctuations within plant canopies have not still been clarified. In this study, field and indoor experiments were conducted for the purpose of obtaining the characteristics of fluctuating light within six plant canopies.
(1) Light fluctuations under natural light within field-type plant canopies were investigated under various conditions and the following results were obtained. That is, (1) The difference between bright and dark lights in light fluctuations showed a daily change almost proportional to the intensity of solar radiation. (2) Light fluctuations were not obvious at various measured points in a citrus crown. (3) Light fluctuations developed markedly as planting density increased. (4) The difference was confirmed between the waveforms of fluctuating lights according to the kinds of plant canopies and considered to be caused by the kinetic energy of wind in plant canopies and the physical characteristics of the plant canopies.
(2) As a result of the wind tunnel experiment related to light fluctuations, the frequency bringing the spectral density of the fluctuating light within each plant canopy (height: about 20 cm) to a definite level or more were about 15 Hz in eggplants, sweet peppers, asparagus and garland chrysanthemums on the case of a wind velocity of 1.7 ms^-1. Also, it was about 11 Hz in the turnip canopy, and 6 Hz in welsh onion, of which the waveform showed a line spectrum. With respect to six plant canopies, there was no great difference in peak frequency between weak wind (1.7 ms^-1) and strong wind (2.5 ms^-1), and the peak frequencies of both cases were within a range of 1.5 Hz N 5.0 Hz. The peak value of power spectra became large in proportion to an increase in wind velocity and this relation was also confirmed within the observed frequency range (Fig. 7) .

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The seedlings of sunflower (Helianthus annuus L. cv. Russian Mammoth) were hydroponic-cultured in a controlled environment at 25°C and at 70% relative humidity. Using three band fluorescent lamps (5000 K) as the main lighting source, the PPFD (400-700 nm) was kept at 200, μmol⋅m^-2⋅s^-1, and each additional PFD (700-800 nm) of far-red (FR) irradiation in four experiments, using FR fluorescent lamps, was kept at 107.1, 50.1, 25.6, and 9.3 umol⋅m^-2⋅s^-1, respectively.
According to the additional level of FR irradiation, the fresh weight, dry weight, leaf area and stem length of the seedlings were increased. The stem length was extended greatly by additional FR irradiation, and leaf/stem dry weight ratio was also changed. Eight days after the treatment by FR irradiation, the stem length was extended 3.8 times longer in FR, 107.1, μmol⋅m^-2⋅s^-1 treatment in comparison with the 9.3μmol⋅m^-2⋅s^-1treatment, and leaf/stem dry weight ratio was 5.8 to 2.7.
It was found that stem extension and leaf/stem dry weight ratio could be controlled artificially by the level of the additional FR irradiation. As a result, it indicates that the evaluation of FR irradiation may be useful in designing the lighting conditions of plant factories or in atria.

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An experimental plant factory using flourescent lamps was developed, and its performance, productivity, and power consumption were investigated through cultivation tests of lettuce. The results are as follows.
(1) Using a close illumination method with fluorescent lamps, three stages of the planting bed could be vertically stacked for cultivation of seedlings and two stages for growth, and the compact cultivation system could be realized. When all 42 flourescent lamps of 110 W/stage were illuminated, the mean light intensity on the floor was as high as 650μE/m²/s (45 klx) .
(2) The environmental conditions were adjusted by an ON/OFF control using a programmable controller. The air temperature, relative humidity, CO₂ concentration, electric conductivity of hydroponic solution and pH were found to be regulated in the range of, respectively, 25±0.5°C in light period/20±0.2°C in dark period, 70±5%, 900±50 ppm, 1.3± 0.1 mS, and 5.5±0.5 under conditions of light intensity of 330μE/m²/s, lighting time of 16 hr/day, and wind velosity of 0.5 m/s.
(3) The lettuce (Kuroha and Greenwave) grew to weigh more than 75 g in 29 days, and the production of an experimental facility was 120 stocks/day. At this time, the seedling weighing about 0.25 g grew acceleratedly, and the fresh weights increased by about 40 times in 9 days.
(4) The daily average power consumption throughout the year was about 300 kWh (45% for lighting, 35% for air-conditioning, and 20% for others) . The power consumption for lighting and the total power consumption for the production of lettuce was found to be about 1.1 and 2.5 kWh/75 g-fresh weight respectively, and energy was saved as compared with the conventional apparatus. However, about 75% of total energy was spent on the growth unit, so to reduce the production cost it seems effective to cut the input of energy and equipment to the growth unit, and invest particularly in the seedling unit which contributes greatly to growth promotion.

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These studies were carried out for the development of non-invasive and continuous moni-toring technique of plant growth in the plant factories.
In this kind of facilities, the environmental factors such as ambient temperature, relative humidity, light intensity, pH of nutrient solution are measured and reported with high accuracy. But, data on plant growth are not measured almost or at all even nowadays.
We have, therefore, tried to apply the method of image processing and obtained sufficient results. They are summarized as follows.
(1) We have developed the plant growth monitoring system by image processing with a personal computer for the plant factories.
(2) The leaf area was regarded as the most useful index of vegetable (lettuce) growth as a non-invasive method.
(3) It was linear to the fresh weight with high coefficient of correlation (>0.95) .
(4) The scheduled harvest was achieved by these techniques.

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