Somatic embryos were initiated from immature seeds of Glaucidium palmatum Sieb. et Zucc. (which is indigenous only in Japan and bears beautiful flowers, however recently extinction by deer attacks is problematic) on the half strength Murashige and Skoog medium containing 2.22μM 6-benzvlaminoDurine. Somatic embrvos can be propagated on the same medium. Temperature of the incubation chamber was one of the important factors for better propagation and growth of the somatic embryos. Plant regeneration was successful on the plant growth regulator free medium. Regenerated plantlets were cytogenetically stable according to the flow cytometric study and DNA content was 1. 35 pg/cell. They were habituated and planted out in the field. Tissue culture can overcome the extinction of potentially endangered species such as Glaucidium palmatum.

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Methods for estimating jelly quantity in tomato fruit by the external appearance have been developed and its estimating accuracy was confirmed.
This method consists of two major processes, first the process of identifying the number of locules in a tomato fruit and then the process of estimating its jelly quantity. The former process was conducted by analyzing a fruit surface image with a novel neural network and the latter by the integration of the jelly area distribution along the major axis of the fruit.
The neural network had two input neurons, six hidden neurons and one output neuron, and a tangent sigmoid-type function was adopted as the input-output transfer function in all neurons. It took hue and saturation information from the fruit surface image and generated a pixel image of the locule partitioning lines. After that, the image was passed through a locule counting process, identifying the number of locules in the fruit with 97% of accuracy.
Jelly area distributions along the major axis of the fruit were obtained through multiplication of the section area distribution by the approximating function of the jelly occupation ratio distribution to the section area.
As the result of estimation by this method, jelly quantity of tomato fruits was estimated with a relative error of only 18.4% on average. This method was sufficiently accurate for consumers at retail markets to select tomato fruits according to their characteristic taste, and therefore it suggests the possibility of development of non-destructive tomato fruits selectors based only on the external appearance.

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A robotic harvesting system was developed to realize selective harvesting for eggplants (Solanum melongena L.) trained in V-shape in a greenhouse. The purpose of the first part of this study is to explain the system components and the global sensing for detecting fruit and to examine the image scanning. The system was composed of control unit, sensing unit, manipulator unit, end-effector unit, and traveling vehicle. The system could run at an inter-ridge space and scan the image of eggplants set at both sides with a combination of the vehicle traveling and manipulator control. The global sensing could detect the existence of fruit from approximately 500 mm away using an image processing technique. The basic experiment of image scanning was conducted to evaluate the global sensing. The success detection ratio was 69.3%. However, unsuccessful detections were observed, such as fruit on an adjacent plant, under-sized fruit, and shade. The scanning time, which includes traveling, image capture, and manipulator motion, within 4 m in length and 1.7 m in height was 317 s. The manipulator motion occupied most of the total scanning time. The fruit direction could be calculated from the centroids of the detected fruit.

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A robotic harvesting system was developed to realize selective harvesting for eggplants. The purpose of the second part is to explain the local sensing for fruit-size judgment and picking control and to examine the harvesting performance. After the system approached the fruit, which was detected by the global sensing, the local sensing judged the fruit size with a fusion of the vision sensor and distance sensor. The end-effector then approached the peduncle. The harvesting scissors cut the peduncle, and the lower blades held it simultaneously. Therefore, the system conveyed it to a container without contact with the fruit. The harvesting experiment was done for eggplants trained in V-shape to examine the harvesting performance. The system could harvest the fruit with a successful harvesting ratio of 29.1%. The main cause of unsuccessful harvesting was that the fruit was invisible owing to leaves or stems. Moreover, it was found that the system misjudged fruit size or dropped fruit during conveyance to the container. The picking method using the lower blades was effective, since no damage to the fruit was observed. The picking time per fruit was 43.2 s/fruit. The work efficiency, including traveling time, was 14.9 m/h. In the future, it will be necessary to develop a more effective fruit-size judgment technique and a traveling method to the adjacent inter-ridge in the future.

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The effects of CO₂ enrichment on the rooting and growth of rose (Rosa cv. Tinek) cuttings combined with auxin treatment were examined. The single node cuttings, bearing one leaf taken from a three-year-old stock plant, were used for the experiment. Number of leaflets of the cuttings were adjusted to two. The basal part of the cuttings was dipped into IBA (indole -3-butyric acid, 4, 000 ppm) for 2-3 seconds before inserted into the rooting medium in the auxin treatment. The cuttings treated and non-treated with IBA were cultured under CO₂ enriched (from 7 a.m. to 5 p.m.) and CO₂ non-enriched conditions in the plastic tunnels in the glasshouse.
The rooting and the growth of root of the cuttings (percentage of rooting, fresh and dry weights of root, number of roots) were promoted significantly by IBA treatment, however the growth and development of the new shoot of the cuttings (fresh and dry weights of the shoot, leaf area, number of leaves, shoot length) were inhibited significantly by IBA treatment. CO₂ enrichment promoted the development and growth of both the root and new shoot of the cuttings. And CO₂ enrichment decreased the depression of the development and growth of the new shoot by IBA. It seems that the promotion of the photosynthetic rate by CO₂ enrichment contributes to the shortening of the production period of the cutting transplants.

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Acoustic responses obtained by striking the fruit have been used for evaluating fruit firmness and maturity using a FFT method. However, those responses are often quite complex and uncertain. This study proposes a new technique to address such complex data. In the method, the attractor of the acoustic response is first described; then, its slope is calculated using the method of least squares. There was a close relationship between the slope of attractor and fruit firmness. The slope of attractor decreased in proportion to fruit firmness. Significant linearity was observed in the relationship between fruit firmness and the slope of attractor. This linearity was confirmed through simulation of a mechanical model (damped vibration model). These results showed that use of the attractor allowed quantitative evaluation of fruit firmness in the time-domain.

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PUE_P and PUE_L, photosynthetically active radiation (PAR) energy utilization efficiencies were calculated by dividing the chemical energy fixed in plants by the PAR energy measured at the top of plant populations and by the theoretical value of total PAR energy on lamp surfaces, respectively. EUE, electric energy utilization efficiency of a closed transplant production system, was also calculated using the total electric energy consumed in the system as a denominator. Tomato seedlings on plug trays were grown for 20 days in the closed system in which air current speed and CO₂ concentration were controlled at 0.53±0.07ms^-1 and 1040±50 μmol mol^-1, respectively, and the effect of leaf area index (LAI) of tomato seedling populations on PUE_P, FUE_L and EUE were investigated. The maximal values of PUE_P, FUE_L, and EUE during the present study were 0.10, 0.075 and 0.015, respectively, which were obtained when the LAI reached the maximal value of 2.4. The maximal value of PUE_P (0.10) obtained in the present study was greater than the theoretical maximal value that Beadle and Long (1985) reported for C₃ plants grown under ambient CO₂ concentration. Results suggest that a closed system is energy efficient for transplant production and the efficiency could be even higher with a greater planting density and optimized air current speed and CO₂ concentration.

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This study developed a multistage transplant culture system that was constructed easily by connecting light and smaller culture units vertically. Its environmental characteristics were then investigated. The culture unit comprises a plastic container box (L : 570× W : 380×H : 340 mm), a light panel with fluorescent lamps, and an ebb-and-flow watering system. Outside air was introduced to the culture space through ventilation windows placed on the sides of the culture space; it was then sent to a space on the light panel with fans installed in the light panel. Finally, the air exhausted from the culture system through ventilation windows placed in the light panel upper side. Air temperature in the culture space was higher than the outside air by about 1.0°C, and a horizontal temperature difference in the culture space was about 1.0°C, when the two florescent lamps (110 W in total) were illuminated. Culture solution was supplied by a pump to the culture system top stage from a water solution tank under culture units. The culture solution was siphoned when the liquid level of the top stage reached the drainpipe height; then, the water solution was supplied to the second stage. Repeating such supply and drainage, the water solution was finally supplied to the whole unit.

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