For the first experiment, plants were randomly clipped at 30 cm
from the soil.The samples were stored for 1 day before preparing
334 stem cuttings of 20, 30, 40, or 50 cm. A wedge cut (45) was
made in half of the stem cuttings for evaluating the effect of
increased surface area in contact with the soil. Data on stem
cutting basal area was taken, and they varied in the range of
130.7e2808.6 cm2. Volume of stakes was calculated as
V ¼ Length Basal area, regardless slight changes in the diameter
from base to top of stakes. The bottom of stakes was buried
5 cm deep in a sandy soil, in the upright position, 15 cm distant
each other. They were daily irrigated until final data collection.
Visible developing buds were counted at 30 days after
planting (DAP), and at 75 DAP, data was taken on surviving
plants, counting of developing buds, shoot and root dry weight, and leaf area. Cuttings that sprouted but did not
develop branches and leaves were considered dead in the
calculation of surviving rate. Dead plants were not considered
in the analysis of growth characteristics. For estimating the
plant leaf area (S), the width (W) of each leaf was measured
and applied to the equation S ¼ W1.87 [18]. Leaf area data was
randomly taken in only 54 plants.
Survival rate was analyzed with Logistic Regression. The
effect of the wedge cut was tested by the F test in the Analysis
of Variance. Quantitative variables were analyzed by Multiple
Linear Regression including length, basal area, and volume as
independent variables, and the Type III Sum of Squares was
used for choosing the variable with the highest influence on
the growth variable. A Simple Linear Regression was then
performed with the selected independent variable.