ISSN:
1573-5036
Keywords:
Huber value
;
Granier method
;
modelling
;
sap flux density
;
Vitis
;
water use
;
xylem flow
Source:
Springer Online Journal Archives 1860-2000
Topics:
Agriculture, Forestry, Horticulture, Fishery, Domestic Science, Nutrition
Notes:
Abstract The Granier-system, a relatively simple and continuous method for measuring sap flux density, has been adapted and evaluated for its use in older, mature grapevines. The original calibration of Granier (1985, Annales Sciences Forestieres, 42, 193-200) could be extended to a sap flux density of up to 400 10-6 m3 m-2 s-1 with only little error at high flux densities. A time lag of around 20 min was apparent between transpiration and calculated sap flow which was attributed to the thermal mass of the sensors themselves. The time lag and the consequently dampened response of the system caused a very low accuracy over short time periods thus reducing the value for detailed plant physiological investigations. However, when integrating over longer time intervals, much of the error cancelled out. For daily values the maximum error was within ±10% and after a period of 89 days only 1.5% error remained. This method is thus best suited for long term measurements of total water use.
Type of Medium:
Electronic Resource
URL:
http://dx.doi.org/10.1023/A:1004708119821
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