Yield Components and Fruit Composition of Six Chardonnay Grapevine Clones in the Central San Joaquin Valley, California

Abstract

Chardonnay grapevine (<i>Vitis vinifera</i>) clones from Foundation Plant Services (FPS), University of California, Davis, were evaluated near Fresno, California. Chardonnay selections FPS 4, 6, 15, 18, 20, and 37 were planted in April 1997 as own-rooted cuttings, and fruit yield and quality were assessed annually between 2000 and 2003. Yield differences among clones were inconsistent, but vines of clone 4 generally had fewer and heavier clusters than vines of other clones, whereas vines of clones 6 and 15 generally had more and lighter clusters. Differences in cluster weight were mainly due to the number of berries per cluster. The fruits of clone 4 had higher soluble solids, lower pH, and similar or higher titratable acidity than the fruits of other clones. However, clone 4 had similar or worse sour rot incidence than the other clones, in contrast with clone 15, which usually had much less sour rot than the others. Results suggest that growers in the San Joaquin Valley, or in other warm-climate areas, might consider planting clone 15 instead of clone 4.