A field portable gas-exchange system for measuring carbon dioxide and water vapour exchange rates of leaves during fumigation with SO2 |
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Authors: | C. J. ATKINSON W. E. WINNER H. A. MOONEY |
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Affiliation: | Department of Plant Pathology, Physiology and Weed Science, Laboratory for Air Pollution Impact to Agriculture and Forestry, Virginia Polytechnic Institute and State University, Blacksburg, Virginia 24061.;Department of Biological Sciences, Stanford University, Stanford, California 94305, U.S.A. |
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Abstract: | Abstract A field portable, steady-state gas-exchange system which measures both CO2 and water vapour exchange of single intact leaves during fumigations with SO2 is described. Within the leaf cuvette temperature, light, humidity and both CO2 and SO2 concentrations are controlled to preset levels. Gas flow and concentrations are controlled by mass flow controllers. Photosynthetic uptake of CO2 can be determined either by differential depletion or null balance measurement. Water vapour exchange is measured differentially and transpiration and conductance to water vapour determined. Sulphur dioxide is measured directly within the cuvette exhaust gas line by UV-pulse fluorescence. The performance of this system under field conditions is described and the physiological measurements compared with those obtained with other systems. |
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Keywords: | Heteromeles arbutifolia gas exchange sulphur dioxide |
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