In this study, skin coloration of eggplant (Solanum melongena L.) growing under the dark treatment (the control) observed with a microscope to determine the distributions of pigment cells in tissue and (was ) anthocyanin in fruit skin. The cultivars/lines of eggplant in the dark treatment were grouped into three pigmentation types (photoreceptive, non-photoreceptive and middle type) for photosensitivity to fruit coloration. An observation of skin surface revealed that all of the cultivars/lines in the control have a large number of pigment cells in fruit skin. However, in the dark treatment, the cultivars/lines of the photoreceptive type have no pigment cells and the cultivars/lines of the middle type have few pigment cells. Therefore, it can be concluded that all pigments in cultivars/lines of the photoreceptive type and a part of pigments in cultivars/lines of the middle type derived from the synthetic pathway of anthocyanin require light for development. Fruit color in the absence of light in these types depends quantities of anthocyanin in a cell and the number of pigment cells in tissue (density). AVIs (Anthocyanic vacuolar inclusions) in vacuole of pigment cells are contained in the cultivars/lines which have nasunin (delphinidin 3-p-coumaroylramnosylglucoside-5-glucoside) for major anthocyanin. Therefore, it is suggested that AVIs peculiar products for eggplant with nasunin. According to the comparison of coloration, (are ) AVIs' existence is shown to have a major influence on fruit color.

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An unmanned vehicle was developed to reduce transportation labor for crops in solution culture facilities. This vehicle runs along the bed, while the distance to the cultivation bed side-wall plane is measured by ultrasonic sensors installed at the four corners of the vehicle body. The advantage of this prototype vehicle is to reduce the turning radius by adopting on opposite-phase four-wheel steering mechanism (4WS). Therefore, 90° turning at the end of the cultivation bed is easy. Some problems found in the turning angle and occurred in the vehicle attitude in cruise control si(were ) nce the yaw rate when steering is big. (errors ) The mounting positions and vehicle dimensions, deflections of the steering mechanism and tire strain, sensor position, and running speed affected the stability of the cruise control. Therefore, the control coefficient had to be set on the basis of the running test when preparing the control program, and significant time was required. In this study, a simulation program for a two-wheel model developed so that the control coefficient decision could be made easily in a short time. In (was ) this way, the setting of the optimum running program was possible using this simulation by changing the mounting position of the sensors, the vehicle specification and steering controls such as the running speed and control periods.

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For the purpose of monitoring the interior state of ‘Shiitake’ mushrooms during drying, especially for estimating the moisture conditions, electric impedance of the cap was measured in a frequency range of 42Hz to 5MHz and in a moisture range of 133.1% d.b. to 1671% d.b.
Cole-Cole plots showed that the circular-arc shape in the plot-curve characteristic of agricultural products disappeared as drying progressed.
The dependency relationship plots of logarithmic resistance to moisture content were divided into two parts at the turning point; showed linear relationships and the other exponential. A moisture estimating formula at 42 Hz of measuring frequency was proposed and its parameters were calculated by the non-linear curve fitting method. The formula had an estimation error of 10.0% in the higher moisture region of more than 590.2%, d.b. and 17.4% in the areas with a moisture content below that threshold on an average relative error basis.

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Grading machines to inspect agricultural products by imaging technologies have been increasingly introduced recently in Japan. In fruit grading operations, it is one of the most important functions to inspect all sides of an object. In this study, two experiments on grading, based on full surface inspection of tomato fruit, were conducted by using a roller pin conveyor with a turning-over device and six image acquisition systems: 1) an experiment to turn over a fruit and 2) an experiment to synthetically grade a fruit based on each of the 6 images.
In the turning-over experiment, 100 tomatoes, which placed a roller pin conveyor with their calyxes down, were spun into upside-down postures through mechanically controlled roller pins. The results showed that this mechanism could be used for full fruit surface inspection, because about 80% success rate was obtained, whereas the success rate of smaller size fruits was lower than that of larger-size fruits due to their shape. After turning over, scattered spin angle of fruit showed variation for defect measurement, therefore some compensation of the result depending on the spin angle and improvement of spinning accuracy were desirable.
The results of the grading experiment confirmed that a set of the roller pins to turn fruit and six color TV cameras could inspect all sides of the fruit and that the grading results could roughly follow human operators' results, during the turning-over process of tomato fruit. However, grading results of fruits with cracks around calyxes different from human grades because of similar crack colors and thin calyx ends.To improve the grading results, it was observed that higher success rate of fruit turning over and higher resolution imaging technologies were required.

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St. John's wort (Hypericum perforatum L.) is a medicinal plant widely used for treatments of neurological disorders, depression, etc. Recently, studies have reported the production of St. John's wort plants under controlled environments with artificial light a promising technique to standardize and enhance the growth and medicinal contents. The present study investigated the effect of the light quality of fluorescent lamps on the growth of St. John's wort plants. The seedlings with 6-8 unfolded leaves were grown for 28 days under blue and red lamps in growth chambers under controlled environments. Dry weight of plants grown under the red lamps was greater compared with that of plants grown under the blue lamps.The CO₂ absorption rate of plants grown under the red lamps was similar to that under the blue lamps. Absorption of red light (600-700 nm) by leaves was lower than that of blue light (400-500 nm). Leaf area, number of unfolded leaves, number of branches from the main stem, and number of nodes of plants grown under the red lamps were greater than those of plants grown under the blue lamps. These findings demonstrated that the difference in dry weight of plants grown under these conditions was not due to the spectral characteristic or photosynthetic ability of leaves but due to the amount of light actually absorbed by the leaves. In conclusion, controlling the light quality can be an important technique for enhancing production of St. John's wort plants.

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