RESEARCH RESULTS FOR NURSERY EN
Tok Furuta
Horticulture Series No. 6
AGRICULTURAL EXPERIMENT STATION
OF
AUBURN UNIVERSITY
E. V. Smith, Director April 1965 Auburn, Alabama
RESEARCH RESULTS FOR NURSERYMEN, 1965
Tok Furuta
GROWTH RETARDANTS:
Azaleas Treating Azalea plants growing in full sunlight with
the growth retardant B-nine or Cycocel resulted 
in more even flower-
ing when the plants were flowered in January following refrigerated
storage for 6 weeks. Treated plants were more 
compact than untreated
plants.
One application of either compound at 
a concentration of 0.25%
was effective. Using a concentration of 0.5% resulted in excessive
retardation and dwarfing.
Retardant treatment was effective on plants growing in full
sun, particularly on varieties such as Sweetheart that normally grow
rapidly and unevenly in pots.
Other woody plants Retardant applications restricted stem
elongation of Roundleaf Japanese Holly, Gardenia, Burford Chinese
Holly, India Privet, Yaupon, Flowering Dogwood, and Common Flowering
Quince. Both B-nine and Cycocel were effective as a soil drench and
as a foliar spray. Flower bud formation of Common Flowering Quince
was increased by use of retardants.
Environment and retardants The observable effect of growth
retardants was dependent on the environment and the use of other
chemicals. Some of the results obtained are summarized as follows:
Growth retardants B-nine and Cycocel were more effective in
restricting stem elongation when light intensity was low than when
intensity was high. Least stem elongation resulted under high light
intensity with application of retardants.
Temperature also influenced the effectiveness of retardants.
They were not as effective at high temperatures (80?F) as at lower
temperatures (50?F).
For soil applications, the soil mixture influenced the effect-
iveness of a given dosage of retardant.
The effect of growth retardants were counteracted by use 
of
Gibberellic acid.
PROPAGATION:
Reducing the leaf surface on softwood cuttings reduced 
the
degree of rooting. None of the commercial "rooting preparations"
replaced the influence of leaves on formation of 
roots.
2
Germinating seeds contain many co-factors that 
stimulates root
formation on cuttings. Extracts of germinating chestnut 
seed con-
tained co-factors that stimulated rooting, using the fung Bean 
Assay.
IRRIGATION:
Solar energy measurements can be used effectively 
to determine
proper time to apply water to container-grown 
plants. Correction for
rainfall was not necessary during periods of 
infrequent and light rain
showers.
Irrigation systems developed specifically 
for growing pot plants
in greenhouses were very effective 
outdoors on container plants. Appli-
cation of liquid fertilizers may also be 
made through these systems,
resulting in automatic applications of 
water and fertilizer. Solar
energy meters, tensiometers, and weighing devices 
may be used to auto-
matically apply water.
IMARKETING TECHNOLOGY:
While results of the electrolytic 
exosmosis test and the electrical
resistance of the shoot was significantly correlated 
to viability, the
absolute reading varied with the 
nature of injury. Injury by heat 
re-
sulted in higher readings than injury 
by cold. This variability limits
present usefulness of the test as a means 
of surveying viability of stored
woody plants.
WOODY PLANTS ON HIGHWAYS:
Since there is only 1 year of results from this 
research, this
report is limited to observations on 
the value of various plants and
practices.
To establish test plantings for 
this project entailed con-
siderable time and expenditures which suggest 
that low cost methods
of establishing woody plants must be 
investigated and procedures adapt-
ed for large scale usage. Several 
alternatives are currently under
study.
Woody plants will control severe 
erosion on soils that wash
easily. In one test planting, large 
plants of Von Ehron Juniper stopped
erosion even where the water ran 
through the plot and the cut 
above the
plants was severely washed.
There are considerable variations 
in microclimates over short
distances, such as from one side to the other side of highway. 
For
example, on one site the average maximum 
temperature during the summer
was 104.7
0
F. Across the road the maximum temperature averaged 0l.F.,
whereas 4,000 feet away average maximm 
temperature was 96.5
0
F. This
microclimate is important in 
considering plant responses and 
performance.
3
Several plants show extreme adaptability 
in being able to survive
and grow in poor locations with neglect. This 
list of plants includes
Robinia hispida, Rosa multiflora, and various prostrate Junipers.
There were many factors contributing 
to poor survival. These
include (1) planting small size plants unable to 
withstand competition,
(2) poor planting stock, (3) waterlogged soil, (4) drought, (5) 
vehicle
traffic on plants, and (6) erosion before the plants become established.