Influence of Rootstocks on Nitrogen, Phosphorus and Potassium Content in Petioles of Four Table Grape Varieties
Four field trials were conducted at Vicuña Experimental Center (30°02’ S, 70°44’ W) located in the Coquimbo Region, Chile, over four seasons, 2002-2003 to 2005-2006, to determine the influence of 10 rootstocks (Freedom, Harmony, Saint George, Salt Creek, SO4, 1613C, 1103P, 99R, 110R, 140Ru, as well as own roots vines) on nutrient content in petioles of vars. Flame Seedless, Thompson Seedless, Superior Seedless and Red Globe grapevines (Vitis vinifera L.). The trials took place at a site that had previously planted to vineyard. The experimental design was randomized complete block with four replicates. Petioles opposite to clusters were taken at bloom as samples and analyzed for total N, P and K content. Significant differences in nutrient levels due to rootstocks were found in all varieties. Rootstocks increased the levels of petiole nutrients (except P) over the values usually reported in literature for table grapes. Vines grafted onto the rootstock ’Salt Creek’ had significantly higher petiole N and P content than those on their own roots vines. Total N level increased 67% in ’Flame Seedless’, 77% in ’Red Globe’, 33% in ’Thompson Seedless’ and 8.5% in ’Superior Seedless’. On the other hand, the petiole P level doubled in all varieties by using ’Salt Creek’ as rootstock. Potassium status was also affected by rootstocks. ’Harmony’ and ’1613C’ showed higher K levels by at least 60% in vars. Flame Seedless, Red Globe and Thompson Seedless as compared to plants grown on their own roots. The present investigation demonstrates that rootstocks may have a considerable effect on grapevine nutrition.