Effect of Light Intensity, Carbon Dioxide Concentration, and Leaf Temperature on Gas Exchange of Spray Carnation Plants

1977 ◽  
Vol 28 (1) ◽  
pp. 84-95 ◽  
Author(s):  
H. Z. ENOCH ◽  
R. G. HURD
2018 ◽  
Vol 227 ◽  
pp. 02008
Author(s):  
Qing Du ◽  
Yanhua Miao ◽  
Yunhui Zhang

In view of the problem that some chicken farms are susceptible to various bacteria and viruses due to poor breeding environment, this paper designs a chicken house environmental intelligent monitoring system based on single-chip microcomputer application to improve the chicken house environment. The system adopts STC89C52 single-chip microcomputer as the main control chip. The sensor collects information on the light intensity, temperature and humidity, and carbon dioxide concentration, and controls the exhaust fan and the illumination lamp, and the environmental parameters can be displayed on the display in real time.


1970 ◽  
Vol 23 (4) ◽  
pp. 775 ◽  
Author(s):  
RW Downes

Wheat stomata offered less resistance to water and carbon dioxide diffusion than sorghum stomata at light intensities of 0�06 and 0�26 cal cm-2 min-i (400-700 nm) but resistances were comparable at 0�46 cal cm-2 min-i. Consequently, transpiration rates were higher in wheat than in sorghum, except at the high light levels, in leaf chamber experiments described here. Rates of photosynthesis were higher in sorghum than in wheat, with the greatest difference at high light levels. This resulted in a greater efficiency of dry matter production relative to water use in sorghum. Transpiration rate increased with increased temperature in both species. Photosynthesis was independent of temperature in wheat, and in sorghum under low light conditions, but otherwise photosynthesis increased with temperature in sorghum. In both species, efficiency of water use decreased as temperature increased at all light intensities. Water vapour concentration difference between the intercellular spaces and the air was comparable in wheat and sorghum and increased with temperature. The carbon dioxide concentration difference between air and intercellular spaces was substantially greater in sorghum than in wheat and increased with leaf temperature. Maximum values were obtained at the intermediate light level in sorghum.


In blue-green algae the hydrogen donors and carbon skeletons required in the fixation of elementary nitrogen may be supplied by the photosynthetic mechanism. Study of the kinetic relationships between the photosynthetic assimilation of carbon and the assimilation of nitrogen into the cell material of Anabaena cylindrica Lemm. has demonstrated correlations between the rates of the two processes consonant with the existence of such biochemical connexions. The effects of light intensity, carbon-dioxide concentration and nitrogen concentration were each studied at four different temperatures by determination of changes in amounts of cell carbon and cell nitrogen in cultures grown for 48 h. Temperature was found to have the most marked differential effect, both low and high temperatures depressing nitrogen assimilation to a greater extent than carbon assimilation. At any given temperature there was a close correlation between the rates of the two processes over a wide range of variation in other factors. Both carbon and nitrogen assimilation were found to be inhibited by relatively low concentrations of carbon dioxide. The rate of carbon assimilation per unit amount of cell nitrogen was found to be related in the usual way to light intensity, but to be reduced at low nitrogen concentrations. The relative rate of nitrogen assimilation was likewise found to be related in the expected way to nitrogen concentration but to increase with light intensity and to be reduced at carbon-dioxide concentrations limiting for carbon assimilation.


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