Early-ripening Grapevine Cultivars for Dry-on-vine Raisins on an Open-gable Trellis

Abstract

‘Diamond Muscat’, ‘DOVine’, ‘Fiesta’, and ‘Selma Pete’ grapevines (Vitis vinifera) were evaluated to determine their suitability for making dry-on-vine (DOV) raisins on an open-gable trellis. The experiment was a split-plot, with training system, head, bilateral, or quadrilateral cordons as the main plot, and grapevine cultivar (Diamond Muscat, DOVine, Fiesta, or Selma Pete) as the subplot. Yield components, fruit composition, and raisin yield and quality were evaluated annually. Vine training style did not affect fruit composition, or raisin yield or quality, but vines trained to quadrilateral cordons produced more clusters on renewal shoots than head-trained vines. ‘DOVine’, ‘Fiesta’, and ‘Selma Pete’ produced about 4.75 tons/acre of raisins, ≈10% more than ‘Diamond Muscat’. ‘Diamond Muscat’ vines produced the most clusters on renewal shoots, an undesirable trait, and the most clusters per vine. ‘Fiesta’ matured later than the other cultivars, therefore it had the lowest soluble solids, the poorest raisin grades, and the highest field moisture at harvest. ‘Selma Pete’ grapes matured as early, or earlier, than the grapes of other cultivars, they had among the highest soluble solids and raisin grades, and the raisins generally dried well. Thus, ‘Selma Pete’ grapevines had the best overall performance of the cultivars tested.