The occurrence of bitter fruit in cucumber (Cucumis sativus L., cv. Kagafutokyuri) was higher in the plots with a lower air temperature (the early growing stage and the non-heating treatment) . Leaf weight was smaller in the plots with a lower air temperature. Total-N, amino acid-N and protein contents were higher or showed a tendency to be higher in the plots with a lower air temperature. Nitrate-N content was higher in the early growing stage than in the later one, while it was higher in the heating treatment than the non-heating.

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The growth, photosynthesis and distribution patterns of ¹⁴C-assimilates were investigated in tomato plants (Lycopersicon esculentum Mill.) grown under shaded conditions using black cheesecloth. Compared with unshaded plants, shaded plants showed a reduced dry weight at about 30% of flower truss, 30-40% of stem and leaves and about 50% of roots after 1-4 weeks of 70-75% shading. The light saturation and compensation points of photosynthesis in shaded plants were lower than those in unshaded plants. The percentage of export of ¹⁴C-assimilates from the ¹⁴CO₂-fed leaf decreased by the shading. The relative distribution of exported ¹⁴C to roots decreased, while that to the flower truss increased with the shading. The relative distribution of exported ¹⁴C to stem and leaves also increased with the shading until the start of fruit enlargement, but decreased subsequently. Some recovery of light-saturated photosynthesis occurred in a week after removing the cheesecloth after 2 weeks of the shading. The plants recovered the dry weight, except for the roots, in a week without the shading.

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The effects of Biofouling control with intermittent ozone injection in model water pipes were investigated. The experimental model pipes used acrylic test pipes (1 m in length) with points equivalent to 150 and 300 m in actual pipes. Fresh cooling water was passed through the model pipes at a velocity of 1.5 m/s. The results of the experiment are summarized below. (1) The dissolved ozone concentration in the water rapidly decreased by a half in about 50 s because of the self decomposition of the ozone due to the high water temperature of 30°C and a pH of 8. (2) After no ozonation for 35 d, the average dry weight of fouling in the acrylic test pipes covered with aluminum film was about 5.4 mg/cm² at each point; nearly 2.5 times higher than those which were not covered. The fouling consisted of about 60% organic matter. (3) By injecting ozone into the fresh water twice daily at 12 h intervals for 5 min each at a dissolved ozone concentration of 10 mg/L, the acrylic test pipes at points equivalent to 150 and 300 m were almost completely free from fouling after a test run of 35 d. The residual ozone concentration at a point equivalent to 300 m was about 0.3 mg/L. (4) The fouling in the acrylic test pipes at points equivalent to 150 and 300 m after 35 d without ozonation were almost completely peeled by an intermittent ozone injection of 10 mg/L for 5 min twice daily at 12 h intervals for 21 d.

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Seed-to-seed experiments using dwarf plants will be conducted in the Cell Biology Experiment Facility (CBEF) set up in the International Space Station (ISS) . Development of a simple system to recycle water transpired by plants is necessary to save space and electrical power. A cooling system using a cooling plate that cools one side of the ventilated culture vessel to enhance water vapor condensation was developed. Effects of side cooling on air temperature, relative humidity and water recycling efficiency in the culture vessel were investigated on the ground. Decreasing the cooling plate temperature lowered temperatures of cooled side and inside air. Cooling treatment also decreased relative humidity inside the vessel less than 90% and lowered the amount of water vapor lost from the vessel through ventilation filters. This seemed to be due to the increased water vapor condensation onto the cooled side. To investigate the effect of increases in outside humidity on water recycling efficiency in the culture vessel, a water vapor transfer model was established. The calculation results indicate that an increase in relative humidity around the vessel can decrease water vapor loss from the vessel, increase water condensation onto the cooled side, and therefore, enhance water recycling efficiency in the vessel. The side cooling system seems to be useful for the CBEF in ISS because relative humidity in the CBEF is controllable.

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For suction of water from a water supply vessel including both water and air under microgravity and g-jitter conditions, a water suction system using hydrophilic fibrous cloth was developed and its performance was evaluated at 0.01-0.02 g-realized for 20 s by parabolic flight in an aircraft. Vessels used for the experiment were glass flasks and had a suction port for suction filtration. A piece of hydrophilic fibrous cloth was arranged along the inner surface of the vessels and the end was fixed to the suction port of the vessels. In vessel without hydrophilic cloths and containing 220 mL of water, the water did not move more than 5 mm along the inner surface and did not reach the suction port under low gravity. When hydrophilic cloths were used, on the other hand, water gathered onto the cloth surface, moved up along the cloth and reached the suction port under low gravity. The amount of water sucked from vessels varied with the amount of water in the vessel and the sectional area of hydrophilic cloths. When the vessels including both water and air were flown during parabolic flight (10^-4 g), water in the vessel moved along the cloth and a water film was formed on the cloth. These results indicated that it is possible to suck water using the fibrous cloth suction system under low gravity and microgravity conditions. Under low gravity conditions, it was difficult to suck water only. However, it is not necessary to separate water from air when the system is used for supplying water to plant root medium consisting of both liquid and gas phases.

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Experiments were conducted to determine the effects of sucrose and polyethylene glycol (PEG) on leaf emergence, rooting and growth of the regenerated bulblets of Fritillaria camtschatcensis Ker-Gawl. which were formed on the small globule-scale of the bulbs in vitro culture. The bulblets were cultured on MS medium containing sucrose of 0 (Cont.), 30, 60, 90 and 120 g/l or PEG of 0, 10, 30 and 50 g/l for 8 weeks under continuous light of 40 μmol m^-2 s^-1 at 20°C in vitro. Also NAA of 0.1 mg/l and kinetin of 0.1 mg/l were supplied to the media. Sucrose concentration of 60 g/1 was suitable for leaf emergence and 60 and 120 g/1 were suitable for rooting from the bulblets. And the concentrations of 30 and 60 g/1 were effective to increases in bulblet growth. PEG was effective for rooting but no effect on leaf emergence. The concentration of 10 g/1 was optimum condition to increase in bulblet growth. Summed up these results, sucrose of 30 to 60 g/1 and PEG of 10 g/1 are the most suitable concentration for bulblet growth of Fritillaria camtschatcensis Ker-Gawl.

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Effect of water stress on flowering of ‘Meiwa’ kumquat trees (Fortunella crassifolia Swingle) was examined to establish a cultivation system for the first-flush flowers. Water stress was established by withholding water until the soil water content reached 45% for moderate water stress treatment, and 35% for severe water stress treatment. Although three sequential flowerings were observed on the control trees, only one flowering was observed on the water-stressed trees. In the control plot, flowering of the first-flush flowers began on 28 June, and about 10 flowers opened per day. Flowering of the second-flush flowers began on 6 July and the number of flowers opened per day reached 300. In moderate water stress treatment, flowering began on 25 June, and lasted until late July without interruption. Therefore, it was difficult to distinguish between the first- to third-flush flowers. In severe water stress treatment, flowering of the first-flush flowers began on 28 June and the number of flowers opened per day reached more than 200. Water stress did not affect fruit growth or quality of fruit. These results indicate that the number of first-flush flowers increases under water stress after termination of new shoot growth and that the required duration of water stress is about 2 weeks.

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