ISHS Acta Horticulturae 493: I ISHS Workshop on Water Relations of Grapevines
SUITABILITY OF THE 'BALL, WOODROW, BERRY'-MODEL FOR THE DESCRIPTION OF STOMATAL COUPLING TO PHOTOSYNTHESIS OF DIFFERENT VITIS SPECIES AND VITIS VINIFERA CULTIVARS IN DIFFERENT CLIMATIC REGIONS AT VARIOUS LEVELS OF WATER DEFICIT |
| Authors: | Hans R. Schultz, E. Lebon, C. Rousseau |
| Keywords: | gas-exchange, pre-dawn water potential, stomatal sensitivity factor, humidity, CO2 concentration Ball-Woodrow-Berry-model, Vitis silvestris, Vitis Oh Budo, Vitis vinifera cvs. Chardonnay, Semillon, Riesling, Syrah, Cabernet Sauvigmon, Grenache, Touriga National |
| Abstract:
Stomatal responses to environmental factors have generally been considered in relation to single variables mostly because interactions between factors have appeared difficult to quantify in a simple way. Linear correlations between stomatal conductance (g) and CO2 assimilation rate (A) have been reported when single variables such as photon flux density varied, yet temperature, humidity and CO2 concentration needed to remain constant. Since under natural conditions these variables change concomitantly, and since a concise description of stomatal responses to the alterations of more than one environmental factor was lacking, Ball et al. (1987) have introduced a model capable to integrate the effects of several environmental factors on g. They demonstrated, that multiplying A, measured under conditions of varying CO2 concentrations, light intensity, vapour pressure and temperature, with a factor consisting of the relative humidity, hs, divided by the external CO2 concentration, Ca, would yield a linear relationship with the simultaneaously measured g. If this holds true for the species of Vitis, it would be a great tool for analyzing stomatal sensitivity under a variety of climatic conditions, different levels of water deficit or even nutritional deficiencies. This information could be used to model grapevine photosynthesis and water use for a range of environmental constraints. The model was tested on field-grown plants of Vitis silvestris, of temperate climate origin, Vitis Oh Budo of humid subtropical origin, and the Vitis vinifera cultivars Chardonnay, Riesling, Cabernet Sauvignon, Syrah, Grenache, Touriga National and Semillon, growing in Geisenheim (Germany), near Montpellier (southern France), and Wagga Wagga (Australia). In all cases the relationships between g and [A · (hs/Ca)] were linear and the stomatal sensitivity could be inferred from the slope of the relationship and used as model input. However, the correlation was less significant for the wild species than for the V. vinifera cultivars. | |
Download Adobe Acrobat Reader (free software to read PDF files) | |
