S20 - Session P3 - `1103 Paulsen´ Rootstock Increases Yield and Fruit Quality of `Chardonel´ Grape in Alabama Growing Conditions

Authors: Elina Coneva *

Currently, the production of bunch grapes in the southeastern U.S. is severely limited by Pierce's Disease (PD), caused by the endemic, xylem-limited bacterium Xylella fastidiosa . As a result, only PD resistant or tolerant hybrid bunch grape cultivars such as 'Chardonel' and 'Norton' could be successfully grown in Alabama. Grape rootstocks can provide resistance to key soil-born pests, soil salinity, and can improve vine drought resistance and the overall vine performance. Current information about rootstock cultivar evaluations in Alabama conditions is severely limited. The objective of our study was to assess the effect of selected rootstocks on the viticultural performance, phenological development, yield and fruit quality of 'Chardonel' grape. The experimental vineyard was established at the Chilton Research and Extension Center (CREC) near Clanton, AL in spring of 2014 and consists of own-rooted (OWR) 'Chardonel' vines and 'Chardonel' grafted on '1103 Paulsen'. Our results indicate that 'Chardonel' grafted on '1103P' produced significantly higher yield in comparison with own-rooted 'Chardonel' vines. 'Chardonel' grafted on '1103P' vines also produced higher number of clusters per vine, larger fruit clusters and sweeter berries when compared to own-rooted 'Chardonel' vinegrape. While the current results provided indications of the impact of '1103 Paulsen' rootstock on vine productivity in the southeastern U.S., to ascertain the long term effect of rootstocks on vineyard longevity, productivity and fruit quality, further evaluations are warranted in the expanding viticultural region of Alabama.