Increasing Flowering Potted Plant Longevity Progress Report — June 1997
FL 32611
The objective of this project Is to identify specific production and
handling practices that can be used to improve quality and increase longevity
of a wide range of flowering potted plants where information is currently
lacking. Specifically, we will fill the voids in the care and 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. GERBERA DAISY
A. Fertilizer Rate:
Rates of 100, 200, 300 or 400 ppm N from Peters 20-10-20 were
applied until flowering on cultivars ‘Swift Red/Orange’ and ‘Red Delight’.
At marketability, plants were sleeved, boxed and held at 45F for 3 days.
Plants were then placed at 7OF at 70 ftc. to determine effects on quality
and longevity. No differences in days to flower, plant height, plant diameter,
flower diameter, number of flowers or number of buds were found among fertilizer
rates. Plant longevity of ‘Red Delight’ averaged 1O days at 400 ppm N and
20 days at 100 ppm, an increase of 1O days when fertilized at the lowest
rate. No differences, however, were observed in longevity for ‘Swift Orange/Red’,
which averaged 18 days, regardless of fertilizer rate.
B. Fertilizer Termination:
Fertilizer was either continued until flowering or terminated 2-3 weeks
prior to flowering at a rate of 200 or 400 ppm N from Peters 20- 10-20
on ‘Swift Red/Orange’ and ‘Red Delight’. Growth parameters were generally
unaffected by fertilizer rate and termination. Although a slight increase
In longevity of 1 to 3 days was observed when fertilizer was terminated,
statistical analysis found no significant differences.
C. Stage of Development at Marketability:
Swift Red/Orange’ and ‘Dark Eye Yellow Delight’ were sleeved, boxed
and stored at 45F for 3 days when buds were either showing color, 50% open
or when fully open. Plants were then placed at 7OF at 70 ftc. to determine
effects on quality and longevity. Plants shipped with buds showing color
continued to develop and open but flower diameter was slightly reduced.
Plants lasted 27 days when shipped with buds showing color, 21 days at
50% open and 19 days when fully open.
D. Transport Conditions:
‘Swift Red Orange’ and ‘Dark Eye Orange Delight’ were sleeved, boxed
and stored at marketable stage (1-2 flowers fully open) at 35, 45 or 55F
for 3, 6 or 9 days. Plants were then placed at 7OF at 70 ftc. Longevity
and quality decreased as transport temperature and time increased. Shipping
for 9 days, especially at the higher temperatures caused a reduction in
longevity of up to 6 days. Transporting gerberas at 35F for up to 6 days
is recommended for maximizing longevity and quality.
E. Interior Conditions:
‘Swift Orance Red’ and ‘Dark Eye Yellow Delight’ were sleeved, boxed
and stored at 45F for 3 days at marketable stage (I -2 open flowers). Plants
were then placed in simulated consumer conditions maintained at 65, 70
or 75F at a light level of 50 or 100 ftc. Longevity at 65, 70 and 75F averaged
25, 18 and 14 days, respectively. Plants lasted 4 days longer when maintained
at the higher light level. Longevity was maximized when plants were maintained
at 65F and 100 ftc. IT.
II. KALANCHOE
A. Fertilizer Rate: - Rates of 150, 300, 450, and 600
ppm N from Peters 20-10-20 were applied until flowering on cultivars ‘Kiebessy’
and ‘Michelle’. At marketability, plants were sleeved, boxed and held at
5OF for 3 days. Plants were then placed at 7OF at 70 fie to determine effects
on quality and longevity. Plant height and flower height were virtually
unaffected by fertilizer rates, while a slight reductionin plant occurred
at the 600 ppm rate. Longevity was greatest at the 150 ppm rate for both
cultivars. An increase of up to 4 days occurred as fertilizer rate decreased
from 600 to 150 ppm. Cultivars differed in plant growth and longevity where
‘Kiebessy’ was larger than ‘Michelle’ and lasted an average of 48 days
compared to 40 days for ‘Michelle’.
B. Fertilizer Termination: - Fertilizer was either continued
until flowering or terminated 4 weeks prior to flowering at a fertilizer
rate of 300 or 600 ppm N on ‘Kiebessy’ and ‘Michelle’. At marketability,
plants were sleeved, boxed and held at 5OF for 3 days. Plants were then
placed at 7OF at 70 ftc. Terminating fertilizer did not affect growth,
quality or longevity. Minor differences in these variables were observed
between cultivars and fertilizer rate. Plants fertilized at 300 ppm N lasted
2 days longe than those fertilized at 600 ppm. ‘Kiebessy’ lasted about
a week longer than ‘Michelle’.
C. Stage of Development at Marketability: - Cultivars ‘Kiebessy’
and ‘Michelle’ were sleeved, boxed and stored at 5OF for 3 days when 1-3
flowers opened, 25% flowers opened or when 75% of the flowers opened. Plants
were then placed at 7OF at 70 ftc. All three stages continued to develop
in postharvest conditions where all flowers eventually opened. Plants shipped
with 1-3 flowers lasted 12 days longer than those shipped with 75% flowers
open and 5 days longer than the 25% open. Both cultivars had long lasting
characteristics with ‘Kiebessy’ lasting 55 days and ‘Michelle’ lasting
49 days when shipped early.
D. TransportConditions: - ‘Kiebessy’ and ‘Michelle’ were sleeved,
boxed and stored at marketable stage (25% flowers open) at 40, 55 and 7OF
for 3, 6, or 9 days. Plants were then placed at 7OF and 70 ftc. ‘Kiebessy’
longevity was not influenced by the transport conditions as plants lasted
44 to 47 days regardless of treatment. ‘Michelle’ was more sensitive to
transport conditions as longevity was reduced I week when transported for
9 days.
E. Consumer Interior Conditions: - ‘Kiebessy’ and ‘Michelle’
were sleeved at marketability (25% open flowers), boxed and stored at 5OF
for 3 days. Plants were then placed at 65, 70 or 75F at a light level of
50 or 100 ftc. Although plants lasted a Iona time at all interior conditions,
interior light and temperature had a significant effect on longevity, Longevity
increased 19 days for ‘Kiebessy’ and 17 days for ‘Michelle’ when maintained
at 65F compared to 75F. Similarly, plants lasted 9 and 7 days longer for
‘Kiebessy’ and ‘Michelle’, respectively, at 100 ftc. compared to 50 ftc.
Longevity of ‘Kiebessy’ at 65, 70 and 75F averaged 58, 45 and 39, respectively,
and longevity of ‘Michelle, averaged 49, 37, and 32 days, respectively.
F: Cultivar Trial: - A total of 28 cultivars were sleeved at
marketability (25% flowers open), boxed and stored at 6OF for 3 days then
maintained in postharvest conditions of 7OF and 70 ftc, All cultivars had
excellent quality and longevity. Buds continued to open and full flowering
was achieved on all cultivars. Longevity ranged from 39 days for cultivars
‘Goldstrike’ and ‘Debbie’ to 66 days for ‘Nathalie’.
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
their effects on postharvest quality and longevity on the following crops:
African Violet, Calceolaria, Cineraria, Elatior Begonia, Exacum, the Festival,
Mardi Gras and Masquerade Series of Gerber Daisy, Gloxinia, Hibiscus and
Hydrangea.
ADDITIONAL BENEFITS:
These evaluations will allow the industry to provide higher quality,
longer-lasting flowering potted plants to consumers
