The visual sensor is an essential component for agricultural robots which work in green-houses, plant factories and so on. We consider that the visual sensor must have three functions, that is discrimination, recognition and position measurement. In the Part 1 of this study, it was observed that cucumber fruit was discriminated from its leaves and stems and that its shape was recognized even when the fruit was divided into two parts from experimental results. In this paper, an experiment of fruit position measurement was done by the method of binocular stereo vision. Besides, an experimental robot harvested some cucumber fruits with the visual sensor. From the experiments, the following were obtained. 1) It was easy to get the correspondence of fruits in left and right images by the method of binocular stereo vision and the fruit position was detected precisely, since cucumber plants were cultivated in inclined trellis training so that few fruits were hidden by leaves and stems. 2) The developed algorithm for position measurement made the correspondence possible even when fruits were partially hidden by obstacles. 3) It was confirmed that the error of measurement by the visual sensor was reasonable and that it could be compensated with the structure of end-effector. 4) After investigating the roles and the performance of visual sensors in the robotic system, appropriate visual sensors for agricultural use should be developed.

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The effects of temperature on fruiting and development in Japanese apricot (Prunus mume Sieb, et Zucc.) cv. Nanko were investigated in sunlit glasshouses with constant temperatures at 10, 15, 20, and 25°C and under field conditions from 1st February. At the lowest temperature treatment, the temperature was kept at 10°C until the end of stage I of fruit development and then increased and kept at 15°C. 1. At higher temperatures, although anthesis was earlier, fruit set decreased because more imperfect flowers were formed. Fruit growth from full bloom followed a double sigmoid curve in each treatment. Because of the shorter period of stages I and II, the fruit maturation period was shorter at higher temperatures. The shorter period of stage II at temperatures higher than 15°C brought a lower cumulative daily-temperature during the whole fruit development period. 2. The weight and size of matured fruits became greatest at 15°C and smallest at 25°C. Some endocarps and seed growth were greatest at the lowest temperature. The total soluble solid in the flesh was higher at higher temperatures, but titratable acidity was not affected by temperature.

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The quality of inflorescence is evaluated by a complicated algorithm which consists of many factors such as length, weight, relationship between leaves and flowers, color, flower position and so on. The quality evaluation is done by the human eye and the criteria depend on seller at auction. However, an objective evaluation for inflorescence is desirable. In this study, some experiments on the evaluation of a spray formation of spray-type chrysanthemum were done by neural network. The chrysanthemums were grown under different conditions regarding planting density, illumination, treatment of plant growth regulator to get various spray formations. In this paper, peduncle length, angle between the main stem and each peduncle and internode length were directly measured manually and were used as input parameters of the neural network. From the results evaluated by the neural network and an expert, the followings were found. 1. Various spray formations were obtained with different planting density and especially very different formation was obtained with the application of plant growth regulators. 2. The spray formation of chrysanthemum grown under the standard planting density was given excellent evaluation by the expert, while that treated with growth retardant had the lowest evaluation. 3. It was observed that the first evaluation by the expert was different from the second one. This implies that human evaluation can be affected by some unknown conditions. 4. Evaluation results by the neural network followed those by the expert adequately. The difference of the evaluated values between them was within ±1. 5. It was considered that the performance of the neural network for chrysanthemums could be improved by the addition of teaching data and input parameters.

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In the Part 1 of this series, it was described how the three features of peduncle length, angle between the main stem and each peduncle and internode length could be used for the evaluation of spray formation of spray-type chrysanthemum. However, these features were measured manually. In this paper, the possibility of evaluation using image processing and neural network was investigated to automatize the process of evaluation. The evaluation indexes were calculated based on the features extracted from the processed image. From the results, the following were obtained. 1. The positions of each inflorescence and the lowest node could be detected using image processing. 2. The evaluation indexes calculated based on the features extracted from the processed image had high correlation with the evaluation value given by the expert. 3. The neural network could have less study iteration than the previous one in Part 1 of this series, since adequate evaluation indexes were used. The evaluation result of the neural network was similar enough to that of the expert.

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Cuttings of “Kyoho” grape were collected during endodormancy (November) and during ecodormancy (January) . Water stress was induced by storing the cuttings in desiccators packed with silica gel. ABA (50 mg/L) and BA (40 mg/L) treatments were given to the cuttings after water stress by completely soaking them in the solutions for 1 h after a presoak in water for 12 h. Water stress enhanced early budbreak and increased the number of buds that broke. Response of budbreak to water stress showed specificity to the water content level attained in the cuttings at the end of stress. Promotive effects of BA and inhibitory effects of ABA on budbreak were significant during endodormancy but not during ecodormancy. Water stress given during endodormancy showed a highly positive interaction with exogenous cytokinins (BA) .

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In this study, the authors made a non-steady state simulation model of the thermal environment and comfort in the rooms where plants were placed. The room which was assumed in the simulation model was the same room that used in our previous experiment (Asaumi et al., J. Archit. Plann. Environ. Eng., AIJ, 464, 1994) . Ornamental foliage plants which were assumed to be placed in the room were Schefflera arboricola “Hong Kong, ”Dracaena fragrans“Massangeana, ”Ficus benjamina and Epipremnum aureum, and the stomatal resistances and shading ratios measured in our previous experiment (Asaumi et al., SHITA J., 4 (2), 1993) were applied. Simulation was conducted concerning the data on January 5, 1993, and the results were compared with the results of our previous experiment (Asaumi et al., 1994) . Furthermore, simulation was conducted concerning the data on the standard sunny day in April. The results of the simulation of January 5, 1993 showed the same tendency as the results of our previous experiment (Asaumi et al., 1994), so the simulation model was considered to be valid. Therefore, the simulation model is useful for the design of the thermal environment and comfort in rooms where plants are placed.

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Rice plants were grown in a natural light phytotron. When plants had 12-13 leaves on the main stem, they were transferred into an artificially illuminated phytotron and acclimated a whole day to measurement conditions of net photosynthesis and transpiration. The gas exchange rates of attached, uppermost fully-expanded leaves were measured under combinations of ambient CO₂ concentration (5-500μmol mol^-1), leaf temperature (20, 25, 35°C), light intensity (400, 800μmol m^-2 s^-1 PPFD) and vapor saturation deficit (1.1-1.5, 1.6-2.5 kPa) . The maximum net photosynthetic rate with elevating CO₂ was obtained under conditions of high temperature, high light and low vapor saturation deficit. The water use efficiency of leaf expressed as the ratio of net photosynthetic rate to transpiration rate increased with elevating CO₂ concentration and the maximum values were obtained at 25°C under low vapor saturation deficit and at 20°C under high vapor saturation deficit, respectively, irrespective of light levels. The double-reciprocal plots of net photosynthetic rate and intercellular CO₂ concentration showed that the highest temperature (35°C) was effective to promote CO₂ fixation by mesophyll cells under high light conditions. Possible interactions among temperature, light and vapor saturation deficit on the gas exchanges of rice leaves under elevated CO₂ conditions were discussed.

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CELSS is to be considered in constructing a closed environment for sustaining life including human beings in space stations and space colonies. The waste management system is a key subsystem of the integrated material recycling system which must be developed to support long-term manned space activity. This paper presents the results of waste processing of rabbit feces using wet oxidation of waste manegement system. It was considered 75% of N in feces were converted to N₂ gas, 60% of Ca in feces remained in the furnace and K in feces were smoothly dissolved in the solution. The insoluble residue contained most of P and Fe in feces. The wet oxidized solution contained Ni and Cr which were eluted from the furnace made of SUS. It was found that the nutrient balance of a wet oxidized solution which added P and Fe, removed Ni and Cr, were not so different compared with a hydroponic solution.

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This study was conducted to decrease fruit cracking of cherry tomato by low osmotic potential solution treatment in hydroponics. Plants cultured in standard concentration of nutrient solution (-0.12 MPa), were transferred only at nighttime (9 PM to 9AM) to low osmotic solution, -0.24 or -0.36 MPa using 40 or 90 mM PEG, respectively. Fruit cracking in -0.36 MPa treated plants decreased to 65% of PEG-free control plants. Fruit and leaf water potentials of the -0.36 MPa treated plants were lower than those in the control plants at nighttime. Based on the above results, it was suggested that water absorption of plants was suppressed by PEG treatment resulting in decrease in fruit cracking. Fruit size, Brix and hardness were not influenced with this treatment.

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Mass propagation of patrinia (Patrinia scabiosaefolia Fisch. ex Link.) was achieved by subculturing shoot-sections and divided axillary shoots on MS based medium with cytokinin. A proliferation rate of 2.7 per 17-d culture period was achieved on the medium with 4.4μM benzyladenine (BA) . Shoots elongated from these in vitro-cultured explants could be rooted on the medium with 0.49μM 3-indolebutyric acid (IBA) . Most of plantlets were readily acclimatized in the soil.

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