This study investigated the effect of high day temperature (30 to 35°C for 5 h from 10: 00 h to 15: 00 h) for 5, 10 and 20 days at different developmental stages of inflorescence on the abortion in Gymnaster savatieri Kitamura.
The plants were exposed to high temperature during the following eight developmental stages of inflorescence: 1) early stage of floret formation, 2) middle stage of floret formation, 3) early stage of petal formation, 4) middle stage of petal formation, 5) late stage of petal formation, 6) complete stage of petal formation, 7) budding stage, 8) 7 to 10 days after budding.
The occurrence of blindness (characterized by necrotic disk and ray florets) was high (70-100%) when exposed to high temperature treatment for 20 days from the early stage of floret formation to the middle stage of petal formation. Also, from the early stage of floret formation to the early stage of petal formation, the percentage of blindness was 60 to 85% even after 5 days of exposure to high temperature occurred after complete petal formation.
The entire necrosis of disk florets (characterized by necrotic disk florets and undeveloped ray florets) was 10% when exposed to high temperature for 10 and 20 days at the late stage of petal formation and for 20 days at the complete stage of petal formation.
The partial necrosis of disk florets (characterized by necrotic central disk florets and welldeveloped ray florets) occurred from the late stage of petal formation to budding stage, and this percentage was high when exposed for 10 and 20 days at the complete stage of petal formation. However, no partial necrosis of disk florets occurred 7-10 days after budding, even when the plants experienced high temperature for 10 and 20 days.

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This experiment was conducted to study the combined effect of high temperature and shading on the flower bud abortion in Gymnaster savatieri Kitamura. The temperature treatments ranged from 30 to 35°C for 5 h from 10 am to 3 pm, for 0, 5, 10 and 15 days and shading was provided with two layers of black cheese cloth for 0, 5, 10 and 15 days. Their effect at eight specific developmental stages of inflorescence was considered.
The abortion occurred from the early stage of floret formation to the budding stage. No abortion occurred 7 to 10 days after budding. The percentage of the abortion increased with the duration of high temperature and shading. Also, the percentage of the abortion became less as the developmental stages of inflorescence advanced.
The occurrence of blindness (characterized by necrotic disk and ray florets) was severe from the early stage of floret formation to the middle stage of petal formation. The percentage of the blindness increased with the duration of high temperature and shading.
The entire necrosis of disk florets (characterized by necrotic disk florets and undeveloped ray florets) occurred at the late stage of petal formation and the complete stage of petal formation. The percentage was high at high temperature and shading for 15 days.
The partial necrosis of disk florets (characterized by necrotic central disk florets and welldeveloped ray florets) occurred from the late and complete stages of petal formation. The percentage was higher at the complete stage of petal formation. Also, the percentage of the partial necrosis of disk florets increased with the duration of high temperature and shading. But, shading alone, without high temperature, did not induce partial necrosis of disk florets even when the duration of shading was increased.

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Plant control systems are characterized by complexity and fuzziness. Genetic algorithm is one of the combinational optimization techniques for complex systems, which utilized genetic operations such as crossover and mutation.
The present work is attempted to apply genetic algorithm and artificial neural network to the optimal control problem for intermittent solution supply in deep hydroponic system. The neural network is used for constructing dynamic model of net photosynthetic rate to drainage and supply in the intermittent solution supply, and the genetic algorithm is used for searching optimal value from numerous responses simulated by the model. The optimal control problem in the present study is to decide 4-step combinational times of the drainage and supply (t₁, t₂, t₃ and t₄), which maximize the net photosynthetic rate of the plant.
By applying genetic operations, we could obtain optimal value easily. In this case, the degree of reaching optimal value (evolution speed) is closely related to crossover rate and mutation rate. Higher the both values increased the evolution speed. For example, when the crossover rate (P_c) and mutation rate (P_m) are respectively equal to 0.8 and 0.8, the optimal value can be obtained within 5-generation. However, lowered the both values caused significant delay of evolution speed. In this case, however, the optimal value can be successfully obtained.
Thus, it was found that the genetic algorithm is very powerful tool for finding the optimal value of objective function contains numerous variables. It seemed that the combination of genetic algorithm and neural network allows available control for growth optimization.

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In the intentional production of crops grown in a plant factory, it is necessary to measure the progress of growth of an individual plant. The image processing of plant growth is an effective tool for intact and non-destructive measurement, so as to be able to digitize continuously the images of plant or leaves with the computer system. There is a significant positive correlation between several growth indices obtained by image processing and the top fresh weight of lettuce plants (Lactuca sativa L. non-heading type) grown in a plant factory. The correlation coefficient between the horizontal projected leaf area and the top fresh weight was highest among the image features of lettuce, i.e. 0.947 or higher. During the early growth period from two-to eight-leaf stage, the correlation coefficient between the horizontal projected leaf area and the top fresh weight was higher than that of the whole span of lettuce's life, i.e. 0.95 or higher. The horizontal projected leaf area for several days after sowing made it possible to estimate the top fresh weight. And so, we have developed an automatic growth measurement system by image processing. To measure individual plants continuously and automatically, we have developed the algorithms for image processing and measurement. The algorithms were composed of the labelling for recognizing individual plant, calculating of argument suited to the growth process and automatic calibration for eliminating the error caused by plant age. From these, the top fresh weight of individual plants was obtained continuously by use of a low-cost automatic plant growth measuring system with a personal computer.

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In order to demonstrate the effect of removal of manure on environment in poultry house, the authors performed measurements in an open type poultry house in Ehime Prefecture from December of 1991 to April of 1992.
Cross section and ground plan of the poultry house are shown in Figs. 1 and 2. The numbers in Fig. 2 indicate measurement points. NH³ and CO² gas generation rate from manure with relation of temperature and weight water content are shown in Figs. 3 and 4.
During the experimental period, 21, 500 White Leghorns were raised in the poultry house. Weight water content of the manure on shelf was about 68% and that at 1st floor was about 38%. The authors removed the accumulating manure on shelf using a trial machine for removal of manure on March 15. Temperature, NH³ and CO² gas concentration, humidity and heat flux inside and outside the poultry house were measured.
Figure 5 shows the diurnal changes in temperature and NH³ gas concentration before the removal of the manure. Figure 6 shows the diurnal changes in temperature and NH³ gas concentration after the removal of the manure. Vertical distribution of NH³ gas concentration at point 5 is shown in Fig. 7.
NH³ gas concentration after the removal of the manure was lower than that before the removal of the manure, especially at 2 cm above the manure on shelf. It is considered that NH³ gas generation from the manure on shelf causes higher NH³ gas concentration in the cages and that decrease of about 10 ppm of NH³ gas concentration will be expected by removal of manure on shelf.
Furthermore, horizontal distribution of NH³ gas concentration shown in Fig. 8 was observed under condition of weak breeze. The highest concentration was 93 ppm at point 6, indicating necessity of improvement of environmental control.

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