Canopy management for fruitfulness

Abstract

This paper reviews the influence of canopy management practices on grapevine bud fruitfulness and fruit yield per node. These practices include trellis-training systems, shoot positioning, shoot orientation, shoot trimming, leaf removal in the fruiting zone, control of shoot number and spacing, and control of shoot vigour. An important theme of this review is the primary role that the light environment of the renewal zone plays in the regulation of shoots per node, bunches per shoot, weight per bunch and primary bud-axis necrosis (PBN). Such necrosis is a possible cause of the low number of bunches per shoot associated with high shoot vigour and canopy shading; increased incidence of PBN results in a greater proportion of secondary, compared with primary shoots. As a consequence, average shoot fruitfulness is decreased by the replacement of the relatively fruitful primary shoots with less fruitful secondary shoots.