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An Analysis of the Relationship between Stem Diameter and Leaf Water Potentials 1
Author(s) -
So H. B.
Publication year - 1979
Publication title -
agronomy journal
Language(s) - English
Resource type - Journals
SCImago Journal Rank - 0.752
H-Index - 131
eISSN - 1435-0645
pISSN - 0002-1962
DOI - 10.2134/agronj1979.00021962007100040037x
Subject(s) - gossypium hirsutum , linear variable differential transformer , water potential , water stress , calibration , tensiometer (surface tension) , water content , botany , soil water , chemistry , horticulture , soil science , mathematics , environmental science , physics , biology , thermodynamics , transformer , statistics , distribution transformer , geotechnical engineering , quantum mechanics , voltage , surface tension , engineering
Changes in stem diameter of a plant are known to follow those in its leaf water potentials; however, a time lag between them and the failure to account for it has been largely responsible for the lack of agreement between measured leaf water potentials and those calculated from stem diameters. A dynamic method is described which infers leaf water potentials continuously from changes in stem diameter and is essentially nondestructive. The method is based on an analogy between a tensiometer‐soil and linear variable difference transformer (LVDT) plant system and requires continuous monitoring of stem diameters and at least two measurements of leaf water potentials as a calibration. Using published data, the method was tested for cotton ( Gossypium hirsutum L.) and red pine ( Pinus resinosa Ait.) and good agreement was obtained between calculated and measured leaf water potentials. The method is simple, accurate, anl easily calculated. It would be useful for both laboratory and field measurements, particularly where a small number of plants is involved.