Effect of rootstock on vegetative growth, yield, and fruit composition of Norton grapevines

Abstract

Norton is an important commercial grape cultivar commonly grown in Missouri and the surrounding region because of its wine quality and disease resistance. However, own-rooted Norton vines typically produce fruit with high pH, malic acid, and potassium, which are known to reduce quality, aging potential, and stability of wine. Additionally, own-rooted Norton vines often produce excessive vegetative growth. Thus, effects of selected rootstocks on Norton fruit composition, yield, and vegetative growth were studied in Phelps County, MO within a commercial vineyard during 2010 and 2011. Rootstocks included 3309C, 101-14, Schwarzmann, 5BB, SO4, 1103P, 110R, 140Ru, 1616C, and 44-53M. Own-rooted Norton vines were also included as a control. Rootstocks did not affect vegetative growth or fruit characteristics (organic acids, glucose, or fructose). However, Norton petiole contents of Ca and P were deficient on some rootstocks in 2010 and 2011. Vines on 101-14, 110R, and 1616C rootstocks produced greater fruit yield than own-rooted vines. Nitrogen, P, K, Ca, Mg, S, and Mn contents in juice were also affected by rootstock, but all were within acceptable ranges. While fruit yields were enhanced by the rootstocks, it may be necessary to alter fertilization and pruning practices to sustain high cropping.