In this study, we aimed to evaluate the influence of defoliation and dry pruning time on the albedo and solar radiation available at the level of clusters and to determine the effect of the latter on the accumulation of soluble solids in grapevines. Two periods of dry pruning and defoliation in part of a Bordô cultivar vineyard grown in pergola system were carried out. Solar radiation was measured using solar meter tubes installed for each treatment. The soluble solids content was determined at harvest using a field refractometer. The dry pruning exerted influence on the albedo, while the highest albedo of the Bordô vine was observed when the dry pruning occurred in the normal season (mid-September) and without defoliation. The albedo ranged from 0.28 to 0.30 during the defoliation period. The results showed that a delay of the dry pruning represents a reduction in the amount of solar radiation available at the grape clusters, while defoliation provides an increase in the incident radiation at the level of clusters. The accumulation of soluble solids is related to the solar radiation available at the level of clusters - the higher the radiation available, the higher the accumulation of soluble solids.
total soluble solids; defoliation; conduction system trellis; balance shortwave
