12 Jan Effects of Production Methods and Root Pruning on Anchorage and Growth of Container-Grown Trees
GILMAN: ANCHORAGE INFLUENCE BY PRODUCTION METHOD AND ROOT PRUNING
The present study compared anchorage and growth of planted container-grown trees considerably larger than previously tested with that of similarly-sized trees transplanted from a field nursery. A second study was designed to compare anchorage and growth of 1) recently planted trees irrigated only on the root ball with that of trees receiving irrigation over a larger soil area, and 2) recently planted trees whose root balls were shaved or not at planting.
RESEARCH STUDY OBJECTIVES
The objectives were to 1) compare the post-planting anchorage of container-grown and field-grown (balled and burlapped / B&B) live oaks (Quercus virginiana Mill.), and 2) evaluate the effects of root pruning and post-planting irrigation placement on anchorage and growth. At seven months after planting, field-grown trees were approximately 50% better secured to the soil than trees from containers. However, removing the peripheral 5cm of the container root ball at planting improved anchorage of container-grown trees by approximately 13% without reducing diameter growth or causing visible symptoms.
Irrigation placement (applied directly on the root ball or to a wider area) had no effect on anchorage and growth. There appeared to be no benefit to irrigating the soil around the root ball during tree establishment in the fine sand soils that receive 120 mm annual rainfall.
Study objectives were to 1) compare the post-planting anchorage of container-grown and field-grown (balled and burlapped / B&B) live oaks (Quercus virginiana Mill.), and 2) evaluate the effects of root pruning and post-planting irrigation placement on anchorage and growth.
CONCLUSIONS
Trees with a 14 cm trunk diameter from a field nursery were better anchored to the soil seven months after planting than identically sized trees from containers. However, anchorage can be improved by shaving off the periphery of the container root ball at planting without sacrificing survival or trunk diameter growth. Longer term studies are encouraged on large trees to determine if results from these short-term studies apply in the long run. Irrigation placement had little impact on growth or anchorage after planting.
Arboriculture & Urban Forestry 2013. 39(1): 1–5
©2013 International Society of Arboriculture