Fruit Characteristics of Six Merlot Grapevine Selections in the Central San Joaquin Valley, California

Merlot grapevine (Vitis vinifera) selections from Foundation Plant Services were evaluated near Fresno, California. Merlot selections FPS 1, 3, 9, 10, 11, and 14 were planted in April 1997 as own-rooted cuttings, and fruit yield and composition were assessed annually between 2000 and 2003. Vines of selection 10 performed best, producing consistently higher yields of fruit than vines of other selections, and the fruits of selection 10 had among the lowest pH and highest titratable acidity of the selections tested. In contrast, selection 1 1 was undesirable as it produced the largest berries, was the most susceptible to sour rot, and the juice of its fruit had the highest pH. Selection 14 produced fruit of good composition, but its yield was lower than the other selections. Selection 3, the current industry standard, performed similarly to selections I and 9, and was not superior to selection 10.