Grapevine canopies are discontinuous and spatially heterogeneous. Thus, their geometrical structure is difficult to characterize. A method based on a three-dimensional discretion of the volume occupied by foliage elements was used to assess spatial and angular distribution of leaf area. The method was applied to two canopy systems (Open Lyre and Geneva Double Curtain) exhibiting different vigor levels. Leaf area density (LAD, m2·m-3), leaf inclination and leaf azimuth distributions were presented for the canopy systems, as are the distributions of lateral shoot leaves within the canopy. An attempt was made to determine the consequences of the canopy system on the grapevine canopy structure. The canopy structure parameters determined in this study were used in a companion paper as input parameters for a radiation model to describe the grapevine light microclimate
