Table 1.

Annual and total shoot growth (cm) for 4 years and total reduction expressed as a percentage of untreated controls for white and red oak in Indiana untreated and treated in April 1995 with paclobutrazol using the soil drench method.

TreatmentYear4-year totalPercentage reduction
White oak
Central leader
Control42.9 a46.6 a41.1 a40.9 a170.5 a
Treated39.0 a20.0 b  6.6 b10.5 b  76.1 b55
Shoots in upper crown
Control38.5 a36.9 a39.6 a31.3 a146.3 a
Treated31.2 a14.6 b  7.0 b  8.1 b  60.9 b58
Shoots in lower crown
Control28.2 a34.1 a32.8 a26.6 a121.7 a
Treated20.2 a  9.3 b  3.4 b  5.8 b  38.7 b68
Red oak
Central leader
Control91.0 a51.3 a62.4 a45.4 a250.1 a
Treated76.9 a26.3 b12.5 b14.9 b130.6 b48
Shoots in upper crown
Control72.5 a42.3 a40.6 a37.4 a192.8 a
Treated67.4 a18.6 b  8.9 b12.3 b107.2 b44
Shoots in lower crown
Control44.0 a35.1 a31.6 a20.1 a130.8 a
Treated51.5 a20.0 a  5.2 b  7.2 b  83.9 b36
  • Pairs of values followed by the same lowercase letter are not significantly different at the P ≤ 0.05 level.