Effects of root pruning #3 root balls when shifting ‘Florida Flame’ red maple into #15 containers on attributes of harvested trees in #15 containers.
| Root pruningz | % trees graded as cull at #3 container positiony | % trees with roots >5 mm diameter over root collar within #3 container dimensions | Diameter five largest roots at #3 container position (mm)x | Diameter of five largest roots on northern periphery of #15 root ball (mm)w | Diameter of five largest roots on southern periphery of #15 root ball (mm)w | % of five largest roots at #3 container position in the top half of root ball that eitherv | |
|---|---|---|---|---|---|---|---|
| Circled | Ascended | ||||||
| None | 78 au | 48 a | 12.7 a | 4.5 b | 4.2 b | 40 a | 6 a |
| Shaved | 23 b | 27 b | 6.9 b | 6.0 a | 5.2 a | 18 b | 1 b |
↵z Shaving removed the outer 3 cm of the root ball periphery and bottom. Trees in #3 and 15 containers for 7 and 9 months, respectively.
↵y Based on roots in the top 5 cm of root ball according to Florida Grades and Standards for Nursery Plants (Anonymous 2015); 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.
↵x Roots measured at the position of the #3 container, before descending, circling, kinking, ascending, or growing straight into #15 substrate.
↵w Roots in the outer 3 cm in the north or south 180 degree circumference of root ball.
↵v Percentage (54%) descending plus kinked roots was not changed by root pruning.
↵u Means in a column with a different letter are statistically different at P < 0.01; n = 40, averaged across eight container types due to insignificant interaction (P > 0.07).