Increasing Flowering Potted Plant Longevity Progress Report –
Increasing POSTPRODUCTION LONGEVITY OF FLOWERING POTTED
PLANTS
Tern/A. Nell, Ria T Leonard, James E. Barrett
and David G. Clark
Department of Environmental Horticulture,
University of Florida, Gainesville, FL 32611
INDUSTRY NEEDS AND PROJECT OBJECTIVES
:
The objective of this project is to identify specific production and handling
practices that can be used to improve quality arid increase longevity of a wide
range of flowering potted plants where information is currently lacking.
Specifically, we will fill the voids in the care arid handling information for
flowering potted plants identified in the Kiplinger Manual and the SAF/FMA
Grades and Standards Manual, thus providing all segments of the industry with
methods for extending longevity and quality for the consumer.
SUMMARY OF WORK COMPLETED:
I. LISIANTHUS
A. Fertilizer Rate: Rates of 150, 250, 350 or 450 ppm N from Peters
15-5-15 were applied until flowering on cultivar ‘Maurine Blue’.
Flowering, plant size and plant quality were not effected by the fertilizer
rates. At marketability, when 6-8 flowers were open, plants were sleeved,
boxed and held at 55F for 3 days. Plants were then placed at 70F at 70 ftc. to
determine effects on quality and longevity longevity was reduced 6-7 days when
plants were fertilized with either 350 or 450 ppm N. Plants lasted 17 days at
the 150 ppm rate and 14 days at the 250 ppm rate. Longevity was greatest when
fertilized at 150 ppm N. Flowers faded significantly in the postproduction
environment in all studies. Flowers that developed indoors were very pale in
color regardless of any treatments imposed.
B. Fertilizer Termination: Fertilizer was either continued until
flowering or terminated 3 weeks prior to flowering at a rate of 150 or 350 ppm
N from Peters 15-5-15 on cultivar ‘Maurine Blue’. Growth parameters were
generally unaffected by fertilizer rate and termination, but leaf quality was
obviously affected. Leaf fading and yellowing were apparent on plants where
fertilizer was terminated, and was greatest on plants where 1 50 ppm was
terminated. At marketability, when 6-8 flowers were open, plants were sleeved,
boxed and held at 55F for 3 days. Plants were then placed at 70F at 70 ftc. to
determine effects on quality and longevity Terminating fertilizer increased
longevity 11 days at both fertilizer rates. Since leaf quality is reduced when
terminating at 1 50 ppm, it is recommended to terminate fertilizer to increase
longevity only at higher rates of fertilizer.
C. Stage of Development at Marketability: Cultivar Maurine Blue’
was sleeved, boxed and stored at 55F for 3 days when either 1, 6 or 12
flowers were open. Plants were then placed at 70F at 70 ftc. to determine
effects on quality and longevity. All plants continued to develop flowers in
postproduction conditions but the number that developed was proportional to
the stage at boxing. Plants shipped with 1 open flower had a total of 6
flowers develop in postproduction conditions compared to the 12 and 14
additional flowers that developed on plants shipped with 6 and 12 flowers,
respectively. I.ongevity was not affected by stage of development as all
plants lasted 18 to 20 days.
D. Transport Conditions: Cultivar ‘Maurine Blue’ was sleeved,
boxed and stored at marketable stage (6-8 flowers fully open) at 45, 55 or
6SF for 3, 6 or 9 days. Plants were then placed at 70F at 70 ftc. No
problems or differences in quality were observed at unboxing. Longevity
decreased as transport temperature and time increased. Shipping for 9 days,
especially at the higher temperatures caused a reduction in longevity of up
to 11 days. Transporting lisianthus at 4SF to 55F for no longer than 6 days
is recommended for maximizing longevity
E. Interior Conditions: Cultivar ‘Maurine Blue’ was sleeved,
boxed and stored at 55F for 3 days at marketable stage (6-8 open flowers).
Plants were then placed in simulated consumer conditions maintained at 65,
70 or 7SF at a light level of 50 or 100 ftc. Longevity at 65, 70 and 75F
averaged 20, 15 and 13 days, respectively. Light level had no effect on
longevity. Lcngevity was maximized when plants were maintained at 6SF.
EXPERIMENTS IN PROGRESS
:
I. HIEMALIS BEGONIA
A. Fertilizer Rate: Rates of 75, 150, 225, and 300 ppm N from Peters
15-5-15 were applied until flowering rig on cultivars ¬ëTakora Yellow’ and
‘Sonata’. At marketability. plants were sleeved, boxed and held at 50F for
4 days. Plants were then placed at 70F at 70 ftc. to determine effects on
quality and longevity. Plant growth and flowering time were unaffected by
fertilizer rates, while a slight reduction in leaf color was observed at the
75 ppm rate. This reduction, however, did not reduce marketable quality.
Plants are currently being evaluated for longevity and quality in
postproduction conditions.
B. Fertilizer Termination: Fertilizer was either continued until
flowering or terminated 2 weeks prior to marketable stage at a fertilizer rate
of 75 or 300 ppm N on ‘Takora Yellow’ and ‘Sonata’. At marketability,
plants were sleeved, boxed and held at 50F for 4 days. Plants were then placed
at 70F at 70 ftc. Terminating fertilizer did not affect growth, flowering or
leaf quality. Plants are currently being evaluated for longevity and quality
in postproduction conditions.
C. Stage of Development at Marketability: Cultivars ‘Takora
Yellow’ and ‘Sonata’ were sleeved, boxed and stored at 50F for 4 days
when 1-3 flowers opened, 25% flowers opened or when 75% of the flowers
opened. Plants were then placed at 70F at 70 ftc. Plants are currently being
evaluated for longevity and quality in postproduction conditions.
D. Transport Conditions: ‘Takora Yellow’ and ‘Sonata’ were
sleeved, boxed and stored at marketable stage (50% flowers open) at 45, 55
and 65F for 3, 6, or 9 days. Plants were then placed at 70F and 70 ftc. No
problems or differences were observed at unboxing among the treatments.
Plants are currently being evaluated for longevity and quality in
postproduction conditions.
E. Consumer Interior Conditions: ‘Takora Yellow’ and ‘Sonata’
were sleeved at marketability (50% open flowers), boxed arid stored at 50F
for 4 days. Plants were then placed at 65, 70 or 7SF at a light level of 50
or 100 ftc. Plants are currently being evaluated for longevity and quality
in postproduction conditions.
F: Cultivar Trial: A total of 23 cultivars were sleeved at
marketability (25% flowers open), boxed and stored at 50F for 4 days then
maintained in postproduction conditions of 70F and 70 ftc. All cultivars
have excellent quality and longevity. To date, all cultivars continue to
flower after 3 months indoors.
FUTURE PLANS:
We plan to evaluate the same series of tests, including production
fertilizer regime, fertilizer termination, stage of development at
marketability, transport conditions, postharvest conditions and cultivar
performance on postproduction quality and longevity on the following crops:
Repeat study of Lisianthus, repeat study of Begonia, Exacum, Gloxinia,
Hibiscus and Hydrangea.
ADDITIONAL BENEFITS:
These evaluations will allow the industry to provide higher quality,
longer-lasting flowering potted plants to consumers.
