. The biology of flowering plants. Phanerogams; Plant physiology; Plant ecology; Plant Physiology. RELATIVE TRANSPIRATION 165 be eliminated, and there is exhibited the physiological be- haviour of the leaf—that is, the difference in reaction shown by the leaf from that of a physical evaporating surface. This is not always true, for Knight(19176)has shown that different strengths of wind do not affect the plant and the atmometer in the same way, even directly ; that is, evaporation from different types of physical surface does not keep a constant relation in still and moving air. If the wind ve
. The biology of flowering plants. Phanerogams; Plant physiology; Plant ecology; Plant Physiology. RELATIVE TRANSPIRATION 165 be eliminated, and there is exhibited the physiological be- haviour of the leaf—that is, the difference in reaction shown by the leaf from that of a physical evaporating surface. This is not always true, for Knight(19176)has shown that different strengths of wind do not affect the plant and the atmometer in the same way, even directly ; that is, evaporation from different types of physical surface does not keep a constant relation in still and moving air. If the wind velocity is constant throughout an experiment, however, the relative transpiration graph does reflect the physiological behaviour of the plant as related to changes in such factors as tempera- ture and light. The same result is secured if, instead of. Fig. 15.—Transpiration (broken line) of Euphorbia capitellata through three days, compared with evaporation (continuous line) and relative transpiration (dot-dash line): the scale of the ordinates is different in the three graphs. (After Livingston, modified.) reducing transpiration and evaporation to unit areas, we simply divide transpiration from any (constant) area by evaporation from any (constant) area. The value so obtained may be referred to as the T : E ratio. It is, of course, proportional to relative transpiration. Only occasionally has the condition of constant wind velocity been observed in determinations of relative transpiration, and results must therefore be interpreted with caution. Example o£ Relative Transpiration.—In Fig. 15 are. Please note that these images are extracted from scanned page images that may have been digitally enhanced for readability - coloration and appearance of these illustrations may not perfectly resemble the original Skene, Macgregor. New York, The Macmillan Company
Size: 2079px × 1202px
Photo credit: © Library Book Collection / Alamy / Afripics
License: Licensed
Model Released: No
Keywords: ., book, bookcentury1900, bookdecade1920, booksubjectplantphysiology
