摘要
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An open-system, whole-canopy enclosure chamber for gas-exchange determinations was tested on three mature grapevines (<i>Vitis vinifera</i> L. 'Aglianico') during the summer of 2005. Data were measured by using an IRGA (Li-COR-840...
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An open-system, whole-canopy enclosure chamber for gas-exchange determinations was tested on three mature grapevines (<i>Vitis vinifera</i> L. 'Aglianico') during the summer of 2005. Data were measured by using an IRGA (Li-COR-840) and were collected automatically every 3 min using a CR23X datalogger mounted inside of the chamber. Temperature, leaf water potential and volumetric soil water contents were monitored at intervals. At harvest, canopy leaf area was about 9 m<sup>2</sup>. On 30 July, recent rainfall had restored soil water status to about 33% of soil volume (near field capacity). Under these conditions assimilation (<i>A</i>) and transpirations (<i>T</i>) showed mean daily values of 20 micro mol s<sup>-1</sup> and 7.5 mmol s<sup>-1</sup> respectively and noon leaf water potentials were -1.1 MPa. By 13 August soil water content had fallen to 24% (close to wilting point), noon leaf water potential was -1.4 MPa and <i>A</i> and <i>T</i> showed values of 13 micro mol s<sup>-1</sup> and 2.5 mmol s<sup>-1</sup> respectively indicating stressed conditions but with increased whole canopy water use efficiency. Gas-exchange data are comparable to values found in the literature for grapevine under stress condition and show that the new canopy chamber is an effective system for measuring the gas-exchange of mature vines in the field.
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