RT Journal Article SR Electronic T1 The Influence of Rootstock on Leaf Water Potential, Yield, and Berry Composition of Ruby Seedless Grapevines JF American Journal of Enology and Viticulture JO Am J Enol Vitic. FD American Society for Enology and Viticulture SP 559 OP 563 DO 10.5344/ajev.1995.46.4.559 VO 46 IS 4 A1 Abdelazziz Ezzahouani A1 Larry E. Williams YR 1995 UL http://www.ajevonline.org/content/46/4/559.abstract AB An experiment was conducted to determine the effect of eight different rootstocks [99 Richter (99R), 110 Richter (110R), Rupestris du Lot (du Lot), 140 Ruggeri (140Ru), SO4, 41B, 101-14, and 1103 Paulsen (1103P)] on the productivity of non-irrigated Ruby Seedless grapevines grown in Morocco. Measurements taken over a three-year period included fruit growth and maturity indices, yield, and pruning weights. Leaf water potential (ψL) was measured at various times during the second year of the study. Results indicated that midday ψL declined throughout the season for all rootstocks, averaging -0.9 MPa at fruitset and -1.3 MPa at fruit maturity. The diurnal time course of ψL averaged across all rootstocks was approximately -0.4 MPa before sunrise, -1.2 MPa around solar noon, followed by a recovery to -0.6 MPa shortly after sunset. An analysis of seasonal, midday ψL indicated two extreme groups of rootstocks: du Lot and 110R had more negative leaf water potentials than 41B and 1103P. The difference between the two rootstocks with the greatest and the least negative average ψL, du Lot and 1103P, respectively, approached 0.2 MPa. Berry weight was greatest for vines on SO4, 99R, and 41B, and lowest for 101-14 and du Lot. At maturity, the lowest fruit soluble solids concentration was obtained on 99R and 41B while the lowest fruit coloration was obtained on 110R, du Lot, 140Ru, and 41B rootstocks. These results demonstrated that rootstock had a significant effect on Ruby Seedless fruit characteristics under non-irrigated conditions.