Impact of Various Canopy Manipulation Techniques on Growth, Yield, Fruit Composition, and Wine Quality of Gewürztraminer

Abstract

Gewürztraminer vines were subjected over three seasons to seven canopy manipulation practices: Control (C); cluster thin (CT); hedge (H); hedge + paclobutrazol (H + P); basal leaf removal (LR); lateral shoot removal (LSR), and; CT/H + P/LR (REM-ALL). Hedging, LSR, and LR reduced °Brix and some parameters of juice color in two of three years, while leaf removal treatments also reduced titratable acidity in 1985 and pH in 1986. Free volatile terpene (FVT) concentration was improved in 1987 by LR, and in 1986 in CT, H, H + P, and REM-ALL vines. Potential volatile terpene (PVT) concentration was also increased over the C treatment in CT, H, LR, LSR, and REM-ALL vines in 1986 and in LR and REM-ALL vines in 1987. Treatments in which leaf area was removed (H, H + P, LR, LSR, and REM-ALL) tended to exhibit lower pruning weights than C and CT vines. Yield and periderm development was not strongly affected by any treatment. Paclobutrazol successfully reduced the length of lateral shoots on H + P and REM-ALL vines. This phenomenon was confined to the upper portion of the canopy only.