Effect of root pruning #3 and #15 root balls when shifting to the larger container size on root attributes of ‘Florida Flame’ red maple in #45 containers.
| Root pruningz | % trees graded as cull at #3 container positiony | % trees graded as a cull at #15 container positiony | % trees with roots >5 mm diameter over root collar within #3 container dimension | Diameter of five largest roots at #15 container position (mm)x | Diameter of five largest roots on north periphery of #45 root ball (mm)w | Diameter of five largest roots on south periphery of #45 root ball (mm)w |
|---|---|---|---|---|---|---|
| None | 95.0 av | 50.0 a | 90.0 a | 10.7 a | 5.3 bA | 4.8 bB |
| Shaved | 42.5 b | 2.5 b | 38.0 b | 6.3 b | 8.1 aA | 6.7 aB |
↵z Shaving removed the outer 3 cm of the root ball periphery and bottom. Trees in #3, #15, and #45 containers for 7, 9, and 15 months, respectively.
↵y Based on roots in the top 5 cm of root ball according to Florida Grades and Standards for Nursery Plants (Anonymous 2005); a cull occurs when there is one (or more) root greater than one-tenth the trunk diameter in the top half of the root ball growing more than one-third around the root ball. No culls occurred in #45 containers.
↵x Measured at the position of the #15 container, before descending, circling, kinking, ascending, or growing straight into #45 container substrate.
↵w Roots in the outer 3 cm in the north or south half of root ball.
↵v Means in a column (lower case) or row (upper case) with a different letter are statistically different at P < 0.001; n = 40, averaged across eight container types due to insignificant interaction (P > 0.15).