Rootstock Effects on Chardonel Productivity, Fruit, and Wine Composition

Abstract

A cooperative study was initiated between the University of Arkansas and California State University, Fresno, to determine the effect of rootstock on productivity, fruit, and wine composition. Viticultural data were collected for four years in Arkansas and three years in California, and wine was made one year. Chardonel scion wood was bench-grafted on Cynthiana, Freedom, Kober 5BB, and Richter 110 rootstock. Grafted vines and own rooted vines were planted in Fayetteville, AR, and Fresno, CA. Vineyard establishment, trellis systems, and cultural practices were standardized between locations. The two locations have different soils and climates, and results differed between locations. Grapes grown in Fresno (3 year means) had higher total soluble solids (23.5 Brix) and titratable acidity (8.0 g/L) and lower pH (3.44) than grapes grown in Fayetteville (4 year means), which had 20.5 Brix, 6.4 g/L titratable acidity, and 3.60 pH. The greatest benefits of using rootstocks were seen in Fayetteville, where yield increases of 40 and 19% were obtained with 5BB and 110R, respectively, as compared to own-rooted vines. Cynthiana produced the lowest yields, and Freedom produced the largest vine size at both locations. Grapes from vines grafted to 110R had a lower pH than own-rooted vines at Fayetteville. Otherwise, there were few composition differences between own-rooted, Freedom, 5BB, and 110R rootstocks. Wines produced from fruit of vines grafted to Freedom had the highest pH at both locations. There were few other differences in wine pH or acidity among grapes that were not attributable to fruit maturity. There was not a major advantage to using rootstock in Fresno. The use of 110R seems to hold an advantage in Fayetteville over own-rooted vines due to higher yield and lower pH.