Precision viticulture and water status : mapping the predawn water potential to define within vineyard zones

An experiment was carried out over two years (2003-2004) in order to monitor the spatio-temporal variability of the predawn water potential at a within field scale. The predawn water potential was measured on 49 points within a field of 1.2 ha. Respectively 7 and 6 measurements were performed at different times in 2003 and 2004. The main results of this work showed that the within field variability of the predawn water potential was significant. It also highlighted the temporal stability of the variability. The zoning performed according to the predawn water potential values was linked to other parameters such as leaf area, trunk circumference, soil resistivity, etc. The result confirmed the temporal stability of the within field variability. It also showed the opportunity to use high resolution data (remote sensing, monitoring systems mounted on conventional machinery) as decision support system to assess a similar zoning or to perform target sampling for a better assessment of the field water statu