Marshall, M.D. and E.F. Gilman
Production Method and Irrigation Affect Root Morphology of Live Oak
J. Environ. Hort. 15(2): 84-87
Trees of live oak (Quercus viriginiana Mill.) were container-grown (CG) or field-grown (FG) to a mean trunk diameter of 9.4 cm (3.7 in), transplanted into sandy soil, and established with frequent or periodic irrigation. Three years after transplanting, trees were harvested with a 1.5 m (60in) diameter tree spade. Root number and root cross-sectional area was evaluated for all roots at the periphery of the tree-spade-dug root ball. Despite similar increases in trunk diameter, FG trees had greater root number and root cross-sectional area than CG trees. The greater root cross-sectional area occurred in roots 5-20 mm (0.2-0.8 in) in diameter at soil depths of 0-25 cm (0-9.8 in) and 75-100 cm (29.5-39.3 in). Irrigation frequency after transplanting had no effect on root number in FG trees. However, root number in CG trees was lower without frequent irrigation.