Table 7.

Growth, chlorophyll and stress measurements for the Dublin maple trees with and without root crown excavationz.

Growthy/chlorophyll/stress measurementTreatment
Excavation Mean (SD)No excavation Mean (SD)
2005 trunk diameter (cm)0.6 (0.3)0.8 (0.7)
2006 trunk diameter (cm)0.7 (0.3)0.6 (0.4)
2007 trunk diameter (cm)0.1 (0.2)0.1 (0.2)
2005 tree height (cm)13.6 (20.8)19.7 (22.6)
2006 tree height (cm)17.6 (23.3)15.2 (23.1)
2007 tree height (cm)20.9(21.4)16.0 (18.5)
2005 canopy width (cm)13.6 (15.5)19.7 (14.8)
2006 canopy width (cm)25.5 (23.2)19.7 (20.3)
2007 canopy width (cm)15.1 (33.2)12.7 (25.4)
2004 twig extensionx (cm)4.9 (3.8)8.0 (6.3)
2005 twig extensionw (cm)5.1 (3.5)7.0 (5.6)
2006 twig extension (cm)10.8 (8.5)8.8 (11.3)
2005 chlorophyll14.7 (5.4)13.6 (4.9)
2006 chlorophyll20.2 (7.2)19.0 (4.7)
2007 chlorophyllx9.3 (5.5)15.1 (11.1)
2004 early fall colorv4.0 (0.7)4.0 (0.7)
  • z Root crown excavation included girdling root removal for approximately 20% of the trees.

  • y Growth measurements except twig extension are increase in growth from the previous year.

  • x Analysis of variance significant at P < 0.01.

  • w Analysis of variance significant at P < 0.05.

  • v Scale of 1–5; 1 = red leaves, 5 = green leaves.

  • SD = Standard deviation.