Arboriculture & Urban Forestry 42(3): May 2016 sylvestris L.) trees developed spiraling roots when in 75 ml propagation containers, causing them to be less stable in the soil seven to nine years aſter planting compared to naturally regenerated trees (Lindström et al. 2005). Other root defects, such as downward-deflected roots, were later recog- nized as causing problems with stability following planting jack pine (Pinus banksiana Lamb. (Chap- man and Colombo 2006). Many studies on conifer seedlings show that root deflection in propagation containers can contribute to long-term growth problems aſter planting in the forest (Krasowski 2003). Roots on shade trees in larger containers also deflect around or downward and prolifer- ate at the bottom of containers (Gilman and Paz 2014)—probably because of suitable air, nutri- tion, and water at the bottom—but the impacts on health and anchorage are poorly documented. Because straight, non-deflected roots appear to be associated with well-anchored trees planted into field soil from propagation (Salonius et al. 2000) and larger nursery (Gilman and Harchick 2014) containers, the main goal of the present study was to determine influence of root form in a container root ball on growth, root archi- tecture, and anchorage, several growing seasons aſter planting into landscape soil. Specifically, the study authors wanted to determine the influ- ence of shaving the periphery of a 12 L root ball when shiſting into a 51 L nursery container on growth and anchorage several years aſter planting the 51 L root ball into the landscape. The second- ary objective was to determine the importance of planting the imprinted (Gilman et al. 2010b) north side of the tree as it stood in the nursery toward the north in the landscape. Acer and Quercus were chosen due to their popularity as urban landscape trees in many temperate climates. MATERIALS AND METHODS Trees and Landscape Planting On 29–30 April 2008, forty 12 L (30 cm tall × 26 cm top diameter) cutting-propagated, container- grown (Airpot™, Caledonian Tree Company, Ltd., Scotland) ‘Florida Flame’ red maples (Acer rubrum L.) and 40 Cathedral Oak® live oaks (Quercus vir- giniana Mill. ‘SDLN’), selected for trunk diameter uniformity from Cherry Lake Tree Farm in Grove- 161 land, Florida, U.S., were shiſted into 51 L solid- walled containers (35 cm tall × 44 cm top diameter, Nursery Supplies, Inc., Chambersburg, Pennsyl- vania, U.S.) 112 km north in Gainesville, Florida, U.S. Trunk diameter averaged 16.8 mm (SD = 1.8) for maples and 14.0 mm (SD = 1.5) for oaks, placing them well within standard size (American Association of Nurserymen 2014). Twenty trees of each taxa were root pruned by shaving (removing, Gilman et al. 2010a) about 3 cm from the root ball periphery and bottom before shiſting. The other 20 trees were shiſted without disturbing the root ball, acting as controls. Aſter shiſting into 51 L contain- ers, the north side of the trunk was marked and always maintained toward the north while trees were in 51 L containers. Trees of each taxon were arranged on black woven nursery ground cloth in separate randomized complete block designs with one tree per treatment combination in each of 20 blocks. Each was irrigated three times daily, pruned to one leader, and staked in June 2008. In October (maples) 2008 and January 2009 (oaks), ten of the twenty blocks chosen at random (2 root pruning × 10 replicates = 20 trees) of each taxon were destructively harvested to measure root sys- tem attributes described in Gilman et al. (2010a). Twenty trees remaining of each taxon (2 root pruning × 10 replicate blocks = 20) were planted into landscape soil in a field [Millhopper fine sand (loamy, siliceous, hyperthermic Grossarenic Paleudults)] with less than 2% organic matter and a bulk density of 1.51 g/cc in USDA hardi- ness zone 8b in Gainesville, on 25–26 November 2008 (maples) and 6–7 January 2009 (oaks). Trunk diameter was 37 mm (SD = 2.6) for maples and 27 mm (SD = 1.9) for oaks, placing them well within standard size. The north mark on the trunk was placed either north or rotated 180 degrees south when field planting. This provided for two tree orientations: north in the nursery to north in the landscape, and north rotated to the south. Trees were in four rows 3.4 m apart. Holes 10 to 15 cm wider than the root balls were dug with straight sides and flat bottoms with height adjust- ment so the top of the undisturbed root ball was about even with the landscape soil surface. One person packed the bottom of holes by foot in an effort to standardize settling. No trees were root pruned when planted into the landscape. Once ©2016 International Society of Arboriculture
May 2016
| Title Name |
Pages |
Delete |
Url |
| Empty |
Ai generated response may be inaccurate.
Search Text Block
Page #page_num
#doc_title
Hi $receivername|$receiveremail,
$sendername|$senderemail wrote these comments for you:
$message
$sendername|$senderemail would like for you to view the following digital edition.
Please click on the page below to be directed to the digital edition:
$thumbnail$pagenum
$link$pagenum
Your form submission was a success.
Downloading PDF
Generating your PDF, please wait...
This process might take longer please wait
