The Effects of Dormant Pruning Treatments on Leaf, Shoot, and Root Production from Bare-Root Malus Sargentii

Abstract

The effects of dormant branch thinning and heading on leaf, shoot and root production were investigated for two-year-old, branched, bare-root trees of Malus sargentii (Sargent crabapple). Each pruning treatment removed 50% of branch length and number of buds. Thinning reduced leaf weight in the subsequent growing season, but heading did not. Compensatory increases in shoot growth from the retained branches were observed for both treatments. Treatments did not affect root weights or leaf: new root ratios. The usefulness of the shootroot ratio as a measure of the balance between transpiration and root water absorption is discussed.

The Effects of Dormant Branch Thinning on Total Leaf, Shoot, and Root Production from Bare-Root Prunus Cerasifera 'Newportii'

“…Shoot intensity (m new shoot growth per m woody branch length) combined the in-f luence of several shoot development parameters, and showed a significant positive increase with thinning severity (Figure 3). Similar shoot growth responses were found for Malus sargentii (1). Thinning had no effect on root production in this study (Figure 2) or in previous work with Malus sargentii (1).…”

“…Similar shoot growth responses were found for Malus sargentii (1). Thinning had no effect on root production in this study (Figure 2) or in previous work with Malus sargentii (1). Reports cited previously (1) found that heading back branches of bare-root trees reduced root growth the following season, and suggested a competitive inhibition of root production by shoot growth.…”

“…Seventy-two branched, two-year-old, bare-root trees (4-5' grade) of Prunus cerasifera 'Newportii' (Newport Plum) were purchased and planted in containers. Details of culture are identical to those reported in a previous paper (1). All branch lengths, base and tip diameters, and numbers of buds were measured before pruning.…”

“…Shoot pruning of dormant, bare-root trees at planting time is widely recommended in the scientific, educational, trade, and popular press (2,3,4). However, most research has not demonstrated favorable effects of such pruning on survival, growth, or shoot:root ratios, as noted in a previous paper (1). This study was initiated to continue the investigation of dormant branch thinning.…”

Influence of Water Stress and Restricted Root Volume on Growth and Development of Urban Trees

“…In most urban settings, however, trees in planters must be replaced after several years (41). The balance between transpiration and absorption determines whether or not internal water stresses develop (33,34). Species with high top-root ratios tend to have low survival rates when outplanted (71).…”