Table 2.

Annual and total shoot growth (cm) for 3 years and total reduction expressed as a percentage of untreated controls of seven species of trees in Indiana untreated and treated in April 1996 with paclobutrazol using the soil injection method.

TreatmentYear3-year totalPercentage reduction
Black walnut
Central leader
Control27.5 a13.5 a7.5 a48.5 a
Treated12.5 a  8.9 a6.8 a28.2 a42
Lateral shoots
Control10.0 a10.5 a8.2 a28.7 a
Treated  7.0 a  5.6 a4.8 a17.4 a39
Red oak
Central leader
Control71.7 a45.7 a31.2 a148.6 a
Treated64.3 b31.3 b28.1 a123.7 a17
Lateral shoots
Control55.4 a23.4 a21.5 a100.3 a
Treated40.1 b17.5 a16.2 a  73.8 a26
Central leader
Control51.5 a54.7 a67.0 a173.2 a
Treated  0.8 b  0.3 b  0.3 b    1.4 b99
Lateral shoots
Control34.0 a27.7 a21.7 a83.4 a
Treated  0.7 b  0.3 b  0.2 b  1.2 b99
White ash
Central leader
Control44.8 a37.5 a37.5 a119.8 a
Treated31.3 b26.3 b35.0 a  92.6 a23
Lateral shoots
Control31.0 a20.5 a15.2 a66.7 a
Treated24.0 a17.5 a13.9 a55.4 a17
White oak
Central leader
Control37.3 a32.0 a28.7 a98.0 a
Treated18.2 b13.7 b20.7 a52.6 b46
Lateral shoots
Control41.7 a28.7 a32.8 a103.2 a
Treated14.7 b10.0 b10.2 b  34.9 b66
White pine
Central leader
Control95.3 a82.3 a89.8 a267.4 a
Treated84.0 b48.0 b55.7 b187.7 b30
Lateral shoots
Control55.4 a46.5 a37.2 a139.1 a
Treated50.0 a34.7 b28.6 b113.3 b19
Yellow poplar
Central leader
Control53.7 a43.0 a63.3 a160.0 a
Treated37.0 b44.1 a59.5 a140.6 a12
Lateral shoots
Control32.3 a28.3 a24.7 a85.3 a
Treated21.8 b22.4 a18.6 a62.8 a26
  • Pairs of values followed by the same lowercase letter are not significantly different at the P ≤ 0.05 level.