Influence of Canopy Density and Cluster Location Within the Canopy on the Berry Microclimate and Fruit and Wine Composition of Cabernet Sauvignon Grown in Four Regions of California PDF Download

Author: Joseph Patrick Cotta
Publisher:
ISBN: 9781267398277
Category :
Languages : en
Pages :

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Book Description
The effects of canopy density and cluster location within the canopy on the fruit microclimate and composition of Cabernet Sauvignon was examined in four premium winegrowing regions of California (Napa, Lodi, Gonzales and Paso Robles) ranging in mean daily temperature and growing degree day accumulation. Canopy density in the fruiting zone was manipulated following berry set by varying the amounts of basal leaf and lateral shoot removal. Treatment effects on the afternoon sun (south or west) and afternoon shade (north or east) portions of the fruiting zone were measured separately. A negative, linear relationship was found between leaf layer number (LLN) in the fruit zone and the percentage of total clusters located on the canopy exterior. Cluster sunlight exposure berry temperature increased as LLN in the fruiting zone declined in all regions. Berry weight was generally least for fully exposed clusters and greatest for shaded clusters. Soluble solids were generally lowest in fully exposed berries and increased as LLN increased. Malic acid content and juice pH generally declined as cluster exposure increased. However, the juice pH trends were reversed for fully exposed clusters, likely because direct sunlight exposure elevated fruit temperatures and delayed fruit ripening. Treatment effects on skin anthocyanin content generally reflected differences in berry temperature. In all growing regions, fully exposed clusters on the afternoon sun side of the canopy had the lowest anthocyanin concentration compared to partially or completely shaded clusters, except in Gonzales, where afternoon berry temperatures were more moderate. Phenolic content increased with cluster exposure whether clusters were present on the afternoon sun or shade side of the vine. Wine sensory analysis was generally well correlated with wine anthocyanin content. Increased or direct exposure to sunlight generally increased wine anthocyanin concentration. Phenol and tannin composition of the wine also generally increased with cluster exposure to sunlight.