A new diagnosis method for rice plants was developed- Four parameters were used to estimate aboveground dry matter (DW) and nitrogen content (Ng). The parameters were the circumference (2πr) of plant hill, plant length (H), chlorophyll value (SPAD), and crop green value (GR). Plant volume which is defined as the product of H and the profile area of a rice plant hill (πr^2) is a good predictor of DW. SPAD and GR are good estimators of leaf nitrogen concentration. Ng has a relatively high positive correlation with the product of plant volume and SPAD or GR.

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The processing methods of AMeDAS data by a personal computer are introduced to supply demands for weather information which has an increasing tendency every year. In this report, weather characteristics in Ishikawa Prefecture were analyzed and investigated from daily data totals during a four year period from 1993 to 1996. The normal values of the Japan Meteorological Agency were analyzed by using the ExcelR software which is a popular table-calculation software program for personal computers. A summary of the results is shown below: These four years were a meteorologically remarkable duration, which a cool and hot summer came mutually from 1993. The deviation percentage of the mean temperature on the basis of ten-days normal accumulation throughout Ishikawa Prefecture was -6.35 in 1993, 7.25 in 1994, 0.50 in 1995 and -1.15 in 1996. On the other hand, the rice situation indexes of four years from 1993 were 88, 103, 98 and 104, respectively. It was found from these analyses that the yielding of rice was strongly influenced by the weather.

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A visualized and dynamic display method which makes the most of the graphics function of a personal computer was applied to the analysis of AMeDAS data. This method was already published in the form of a dynamic display software program of AMeDAS data by S. Kawashima of the National Institute of Agro-Environmental Sciences. In this study, (1) Kawashima's software program written by the N_<88>BASIC language, was changed to the F-BASIC386 language for the purpose of making a wide computer applicability. (2) "A digital map 1 km (elevation data meshed into 1 kilometer)" of the Geographical Survey Institute of the Ministry of Con- struction is used to display background- Consequently, the relationship between weather and geographical features become evident. (3) Hourly portraits required from continuous display pictures were placed in an outfile. This portrait was used for weather analysis after color printing. The computer used FM-TOWNSII, which has a 12 Mbyte size in the main RAM. In this report, reading and processing methods of AMeDAS magnetic tape data by a main-frame computer in the data processing center of Kyoto University will be described as well as how to make a map using the display background and the details of an improved dynamic display software program.

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In this paper, AMeDAS data in 1994 and 1995 are shown graphically on the computer display by a dynamic display software program. Hourly pictures (size:640 × 480dots) of four meteorological elements (ie;air temperature, wind direction-wind speed, sunshine duration and precipitation) are out files to a floppy disk in the form of image data from continuous display pictures by an interruption processing using a PF (function) key of the computer. These selected pictures are printed out at 720 dpi on a color printer by using GV(Graphic Viewer) and Paint software tools. From the analysis of typical meteorological pictures in winter and summer seasons, which includes typhoons, the relationship of meteorological elements and the correlation between weather and geographical features became evident. Therefore, it was concluded from the dynamic display method of AMeDAS data that hourly changes in air temperature, wind direction, wind speed, sunshine duration and precipitation in each of the measuring stations could be understood easily, in addition to being effective for displaying measured data in other meteorological robots.

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Japanese pear 'Shinsui' is one of the early-maturing cultivars, and its fruit growth and harvest period can be manipulated by forcing culture. Under plastic, however, its poor sugar content in fruit could not be improved This experiment was conducted to examine how to increase fruit yield and to improve sugar content in 'Shinsui' fruit by CO_2 treatment. A high CO_2 concentration of 500 〜 600 ppm was maintained in a plastic house covered only the roof for 6 weeks (from June 3 to July 14, 8:00 〜 17:00, every day) before harvest for 18-year-old trees of 'Shinsui', and investigated rates of the net assimilation and the increase of dry matter in lateral branches and fruit. 1. Mean fruit weight in the CO_2 enrichment was 307g, which was significantly larger by about 30g than that in the control atmosphere. 2. Increase of dry matters per lateral branch and fruit was 93g(145% of control) and 80g(149% of control) for 6 weeks, respectively, in the CO_2 enrichment. The rates of dry matter increase in the lateral branch and fruit were 176% and 130%, respectively, in the CO_2 enrichment, which was 56% and 87% higher than those of the control. 3. Net assimilation rate (NAR) was 3.45g・m^<-2>・day^<-1> (145% of control)in the CO_2 enrichment. 4. Total sugar content in fruit was 13.6% in the CO_2 enrichment, which was 1.7% significantly higher than that of the control. Particularly, sucrose content was 1.4% which was more than twice the control. It appears that CO_2 enrichment before harvest was effective for improvement of fruit quality of 'Shinsui', because the rate of dry matters in the lateral branches increased to 176%. In particular the sucrose content in fruit increased more than 2 times of that in the atmosphere.

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The changes of the technological efficiency of each dairy farm by an application of DEA during the last ten years were estimated. We found four critical factors forming technological efficiency and identified following four types of the dairy farm: Group-A with high technological efficiency, Group-B with largely improved efficiency, Group-C with unstable efficiency, and Group-D with consistently lower efficiency. Second, we clarified the reasons why the above four groups existed- The reasons were as followings: a) Group-A was conditioned under low input-high output, b) Group-B was placed under high input-high output, c)in the cases of Groups-C and D, the factor effecting its efficiency was not fixed or improved, and d)the factors affecting its efficiency ware newly formed.

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The vegetational control of paddy levees is one of the important works to maintain the structure strength of levees. In this study, the author investigated the vegetational change on the paddy levee with annual cutting frequency during the six years from 1992 to 1997 in Okayama Prefecture Agricultural Experiment Station. The three plots of cutting frequency, 2-3, 4-5, and 6-8 times a year, were adopted here, and the dominant species grown on the levees used for the survey was bahiagrass or purple nutsedge. At the 6-8 cutting frequency, the dominance of bahiagrass increased by year, but contrary to this the purple nutsedge dominance decreased. On the other hand, at the 2-3 times cutting frequency bahiagrass become less dominant, and needlegrass became the dominant species. However, the vegetational change was not observed in the plots with the 4-5 cutting frequency. The vegetational control by cutting treatments was regarded as one of the important factors contributable to sustain or increase the physical strength of the levee structure. These results suggest that the best annual cutting frequency on levees is 4-5 times in the western districts of Japan.

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