Abstract

The goal of this study was to test the feasibility of extrapolating a single vine water status measurement to several locations using ancillary information with a high-spatial resolution. An experiment to identify and test the model was carried out over a commercial 'Syrah' field located in the Languedoc-Roussillon Region, France, during the 2003 and 2004 growing seasons. A regular grid of 49 measurement sites was distributed over the field. For each grid point, measurements were conducted to assess: (i) predawn leaf water potential (PLWP) at seven dates in 2003 and six dates in 2004, and (ii) vine vegetative expression (vine trunk circumference, expose leaf area and pruning weight). Results showed that most of the variables of plant (water status and vegetative growth) were highly correlated among them and with NDVI and ERa. Also, the proposed model was able to predict spatial variability of PLWP with a spatial and temporal mean error of 0.09 and 0.10 MPa, respectively. This result shows the ability of this approach to extrapolate the plant water status from one reference site by taking into account spatial variability characterised by ancillary information. Further studies will aim to confirm the relevancy of this approach for different seasons, locations and cultivars.