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Response of Bromeliads to Fertilizer Rate and Shippin Environment
R.T. Poole and R.W. Henley' Library
University of Florida, IFAS
Central Florida Research and Education Center-Apopklaniversity of Florida
CFREC-Apopka Research Report, RH-92-22
Several genera of epiphytic plants commonly known as bromeliads are grown
commercially for use as exotic specimen plants. Central Florida growers sometimes observe
leaf tissue breakdown occurring on previously healthy bromeliads during shipping and
handling. The degree of damage can range from none to severe among plants shipped
together or under similar conditions and plants can show damage even when total handling
time is less than 2 hours.
Growers describe this damage as brown necrotic areas (necrosis) which are irregular
in shape and size. Necrosis is most likely to occur at the bend in the arch of the leaf,
structurally the weakest part of the leaf blade. The following experiments examined
production, shipping and handling environment of 4 species of bromeliads in an attempt to
determine the cause of post-production leaf necrosis.
Experiment 1: Fertilizer rate and shipping/handling room vs direct storage
Experiment 1, was a 2 x 2 x 2 factorial test with 3 replications per treatment, initiated
on 27 June 1988. Small good quality Aechmea 'Friederike' in 6-inch pots containing a 1:1:1
(v,v) commercial growing mix of peat:pine bark chips:perlite were obtained from a local
grower. Plants were grown to salable size in greenhouses where maximum light intensity
was 2000 ft-c, minimum air temperature was 70F and maximum air temperature was 85 or
95F depending on treatment.
Bromeliads were watered and fertilized once a week. Each plant received 150 ml of
a stock solution containing 50 or 200 mg N, 7.0 mg P and 30 mg K poured directly into the
vase-like structures formed in crown by overlapping leaves. When vases were filled, excess
stock solution dripped around the leaf bases into growing medium.
At 1:00 pm on 27 September 1988 (a bright sunny day with outside air temperature at
mid-day exceeding 900F) half of plants receiving 85F maximum air temperature and half of
'Professor of Plant Physiology and Professor of Environmental Horticulture, respectively,
Central Florida Research and Education Center, 2807 Binion Road, Apopka, FL 32703.
plants receiving 95F maximum air temperature were moved to an air conditioned
shipping/loading area where air temperature was maintained at 74*F and maximum light
intensity (a combination of cool white fluorescent lights and natural sunlight) was 150 ft-c,
during daylight hours. Twenty-four hours later, plants from shipping/loading area and those
remaining in greenhouses were placed in dark storage coolers where air temperature was
maintained at 60F. After 48 hours storage time, bromeliads were returned to their original
greenhouse conditions. When plants were examined two days later, on 30 September 1988,
no foliage damage was detected. Fertilizer rate did not affect quality during shipping but
plants receiving 200 mg N were darker green compared to plants fertilized with 50 mg per
Experiment 2: Fertilizer rate and growing medium temperature
Experiment 2, initiated on 6 October 1988, utilized Aechmea 'Friederike' plants
grown in experiment 1. Plants were moved to a greenhouse where maximum light intensity
was 2000 ft-c and air temperatures ranged from 70 to 850F. Growing medium temperatures
were held constant at 65, 75 or 850F by placing pots into forced air chambers specially
designed for that purpose.
Starting on 12 October 1988, plants received 48 hours dark storage in 60F coolers,
as in experiment 1. When bromeliads were examined 48 hours after storage treatment, no
foliage damage could be found.
Experiment 3: Production air temperatures and shipping/loading period vs direct
Experiment 3 was designed as a 3 x 2 factorial test with 4 replications per treatment.
Testing began on 7 June 1989, when excellent quality Aechmea 'Fasciata', Aechmea 'Fascini'
and Neoregelia carolinae 'Perfecta Tricolor' were obtained from local growers. All
bromeliads were growing in 6-inch pots containing similar light weight commercially
produced potting media.
Plants were grown to salable size in greenhouses where maximum light intensity was
2000 ft-c. Air temperatures ranged from 70F minimum to 85, 90 or 95F maximum,
depending on treatment. Plants were watered and fertilized once per week with 100 ml of a
liquid stock solution containing 100 mg N, 5.0 mg P and 20 mg K poured into the vase of
each plant. Stock solution overflow from vases maintained adequate growing medium
On 15 August 1989 (a bright sunny day with maximum outside air temperature
exceeding 90"F), half of plants grown in each maximum air temperature were moved to a
shipping/loading area. Shipping/loading room air temperature was maintained at 740F and
maximum light intensity (a mixture of cool white fluorescent and natural sunlight) was 150
ft-c. After 24 hours, plants from shipping/loading area and plants remaining in greenhouses
were moved to dark storage coolers where air temperature was maintained at 600F.
Bromeliads were removed from coolers after 48 hours and returned to original
greenhouse conditions. When plants were evaluated 2 days later, on 20 August 1989, no
foliage damage was visible on any of the bromeliads tested. Plants were maintained in
greenhouses under conditions previously described until used in experiment 4.
Experiment 4: Plant sleeves used during storage
On 9 September 1989, another hot sunny day, Aechmea 'Fasciata', Aechmea 'Fascini'
and Neoregelia Carolinae 'Perfecta Tricolor' plants grown in experiment 3 were separated
into two groups. Group 1 plants, those receiving 24 hours shipping/loading treatment in
experiment 3, were again moved from greenhouses to shipping/loading area during the
hottest, brightest time of day. Air temperature was maintained at 74F and plants received
150 ft-c from a mixture of cool white fluorescent lights and natural sunlight. Group 2 plants,
as in experiment 3, remained in greenhouses until moved to coolers. After 24 hours, both
groups 1 and 2 were placed into paper plant sleeves and moved into 600F dark coolers.
Sleeves were carefully removed from plants when bromeliads were returned to
original greenhouse conditions after 48 hours dark storage at 60F. When plants were
examined on 24 September 1989, no foliage necrosis was found on any of the plants tested.
Experiment 5: Shipping air temperature
Experiment 5 was initiated on 10 October 1989, when good quality undamaged
Neoregelia Carolinae 'Perfecta Tricolor' were obtained from local growers. All bromeliads
were grown in 6-inch pots containing similar light weight commercially produced potting
media and similar (1-1-1 formulation) slow release fertilizer sources. Plants arrived at
CFREC-Apopka in cardboard boxes left open on top. Boxed bromeliads were placed in dark
coolers where air temperatures were maintained at 85, 95 or 105F. After 6 hours, cooler
temperatures were reset at 70F. When plants were unpacked and examined on 13 October
1989, no foliage damage was found.
The temperature and light intensity changes bromeliads were subjected to under
conditions of these experiments did not damage any of the species used. Increasing fertilizer
rate in experiment 1 produced darker green colored plants but did not have any effect on
post-production foliage necrosis. Even though results of these tests did not determine the
causes of necrosis, they have demonstrated that these four bromeliads were not sensitive to
the changes in air temperature or light intensity we tested. More experimentation is
underway since necrosis development during storage and shipping must be eliminated for
volume of commercially produced bromeliads to significantly increase.
UNIVERSITY OF FLORIDA
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