Sampling Vidal Blanc Grapes. I. Effect of Training System, Pruning Severity, Shoot Exposure, Shoot Origin, and Cluster Thinning on Cluster Weight and Fruit Quality

Abstract

Training system and pruning severity treatments and several vine canopy conditions were investigated for their effects on cluster weight and juice quality. Training system had no major effect on measured parameters. Decreased pruning severity resulted in decreased soluble solids of juice. Cluster thinning resulted in higher weight and soluble solids/acid ratio for clusters from thinned vines. Exposure of shoots to sunlight resulted in higher soluble solids and lower acidity in all cases. Clusters on shoots arising from count buds were heavier, higher in soluble solids, and lower in acidity than those from non-count positions. On unthinned vines, base clusters on the fruiting shoot were heavier than the second cluster and were higher in soluble solids.