Postveraison Shoot Trimming Reduces Cluster Compactness without Compromising Fruit Quality Attributes in Organically Grown Sangiovese Grapevines

Vine performance following preveraison shoot trimming is well documented, but the consequences of this treatment later in the season are poorly understood. Here, a four-year study was conducted in a mature vineyard of Sangiovese (clone 12T) grafted onto Kober 5BB rootstock at a spacing of 1 m x 2.8 m (intra-and interrow) to analyze the influence of postveraison shoot trimming on vine growth characteristics, cluster architecture (cluster compactness), and yield from a physiological viewpoint. The treatments consisted of shoot trimming during postveraison in a randomized block design with eight replications (six vines each). Three treatments were imposed when soluble solids reached 15 Brix in August (40 to 45 days before expected harvest): light trimming (14 nodes), severe trimming (10 nodes), and an untrimmed control. Following the treatments, vine growth characteristics, cluster morphology, and fruit quality attributes were measured. Postveraison shoot trimming (especially severe trimming) reduced cluster weight, cluster compactness, productivity, and total yield. Effects on fruit quality included lowering of Brix and pH, with minor effects on titratable acidity, yeast assimilable nitrogen, the anthocyanin profile, and total anthocyanins. These results demonstrated that postveraison shoot trimming can be a valuable production practice by reducing cluster compactness without compromising overall fruit quality in Sangiovese

Effects of late defoliations on chemical and sensory characteristics of cv. Uva Longanesi Wines

In this study we investigated the effects of late leaf removal on the berry and wine composition and on wine sensory characteristics of Uva Longanesi, a late maturing red Italian grape variety, which wines are characterized by high levels of alcohol and excessive astringency, the latter apparently intensified by late defoliation practices. During 2008 season, spur-pruned trained vines were submitted to manual defoliation (4 basal leaves) at the onset (DEF I, 210 DOY) or at the end (DEF II, 231 DOY) of veraison and compared with non-defoliated plants (CON). On every DEF II vine, since defoliation until harvest, a cluster was shaded (DEF II + shading). A decrease of the berry soluble solids and skin anthocyanins was found in DEF I vines. Defoliation modified composition and sensory characteristics of wine with DEF II having higher alcohol strength and astringency compared to DEF I, whereas CON wines displayed intermediate values. The practice and timing of partial late defoliation greatly affected the chemical and sensory attributes of win