巻号一覧
46 巻 (1990 - 1991)
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46 巻, 1 号
選択された号の論文の6件中1～6を表示しています
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平野 高司, 清田 信, 北宅 善昭, 相賀 一郎1990 年 46 巻 1 号 p. 1-7
発行日: 1990/06/10
公開日: 2010/02/25
ジャーナル フリーDust cover on leaves is considered to affect photosynthesis directly, mainly by shading leaf surface, increasing leaf temperature and plugging stomata. This study was carried out to make clear these physical effects of dust on photosynthesis. Four classes of JIS Z 8901 dust (Carbon-Black and Kanto-loam powder Coarse, Fine, Ultrafine), which were different in particle size and had pH values around neutrality, were applied to upper surfaces of leaves of kidney bean and cucumber plants at various densities. These two species were different in stomatal density. Both net photosynthetic rates and leaf temperatures of dusted leaves and clean leaves were measured at the same time, over a range of light intensities.
The following results were obtained both in kidney bean and cucumber plants.
(1) Photosynthetic rate was reduced by dust. As dust density on leaf surface increased, it was reduced further.
(2) When carbon-black was applied, leaf temperature increased by 3°C at the maximum, but none of three classes of kanto-loam powder increased leaf temperature.
(3) Regardless of dust characteristics or dust density, the reduction in photosynthetic rate was nearly equal to the reduction in PPFD incoming to upper surface of leaf by dust accumulation, in all measurments in this study.
Therefore it seemed that the shading leaf surface was the most important of the injurious physical effects of dust on photosynthesis.抄録全体を表示PDF形式でダウンロード (343K) -
1990 年 46 巻 1 号 p. 8-8,30
発行日: 1990/06/10
公開日: 2010/02/25
ジャーナル フリーPDF形式でダウンロード (156K) -
原薗 芳信, 池田 英男1990 年 46 巻 1 号 p. 9-17
発行日: 1990/06/10
公開日: 2010/02/25
ジャーナル フリーWe developed a simple and light weight hydroponic system using rockwool substrate for growing plants as a rooftop vegetation. The system was set with the vegetation section on the rooftop of the university building at the height of 16m above the ground level, where tomato plants were cultivated. A control section with no plants was also set on the same floor.
Humidity in the air surrounding the vegetation section increased by approximately 15% due to the tomato plants transpiration. Air temperature in the vegetation section decreased by approximately 1°C compared to that of the control section on cloudy days, while it seldom decreased on clear days. The rooftop surface temperature of the control section rose to over 50°C at clear midday, while at the vegetation section it infrequently rose to about 40°C, which made the difference in the total heat transfer into the room below by 2MJm-2 in the value integrated over clear daytime. As a result, the air temperature in the room beneath the vegetation section was kept approximately 2°C lower than that beneath the control section after July. Heat flux through the multi-layer slab of the rooftop was obtained by means of the response factor method, and the latent heat transfer was estimated by the amount of supplied tap water for cultivation and then the heat balance on rooftop floor was examined. Sensible heat flux of the vegetation section was the same as that of the control, which corresponds to the fact that the air temperature of the vegetated area did not decrease. At the vegetation section the latent heat flux shared 50-60% of the net radiation flux, and the heat flux to the concrete floor decreased to approximately 25% of that at the control section. The results indicate that the vegetation system can be successfully applied to reduce the thermal load on buildings and to moderate dry climates in urbanized areas.抄録全体を表示PDF形式でダウンロード (531K) -
山本 晴彦, 本條 均1990 年 46 巻 1 号 p. 19-22
発行日: 1990/06/10
公開日: 2010/02/25
ジャーナル フリーNon-attach and non-destructive measuring method for estimating leaf area index (LAI) and biomass (top dry weight) of crops was applied for soybean canopy using portable spectroradiometer under natural conditions in the western Japan.
In this paper, we tried to find the most effective band or index suitable for estimating LAI and biomass.
1) The most effective index of spectral reflection characteristics for estimating the leaf area index of soybean canopy is R850nm/R650nm. The regression equation is LAI=0.250(R850nm/R650nm)-0.149. In this case, the correlation coefficient is 0.95.
2) The most effective index of spectral reflection charateristics for estimating the biomass in the duration from the early growth stage to the early seed development stage is R850nm/R650nm. The regression equation is biomass (top dry weight, g·m-2)=21.6(R850nm/R650nm)-42.1. The correlation coefficient is 0.96.
3) The effective index of spectral reflection characteristics for estimating the biomass in the duration from the middle seed development stage to the yellow ripe stage is R450nm/R1050nm. The regression equation is Biomass (top dry weight, g·m-2)=-9070(R450nm/R1050nm)+921.8. The correlation coefficient is -0.85.抄録全体を表示PDF形式でダウンロード (254K) -
菊地 正武1990 年 46 巻 1 号 p. 23-29
発行日: 1990/06/10
公開日: 2010/02/25
ジャーナル フリーPDF形式でダウンロード (445K) -
角屋 睦1990 年 46 巻 1 号 p. 31-33
発行日: 1990/06/10
公開日: 2010/02/25
ジャーナル フリーPDF形式でダウンロード (172K)
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