| Material Information
||Factors influencing chilling damage of foliage plants
||ARC-A research report
||3 p. : ; 28 cm.
||Poole, R. T ( Richard Turk )
Conover, Charles Albert, 1934-
Agricultural Research Center (Apopka, Fla.)
||University of Florida, IFAS, Agricultural Research Center-Apopka
||Place of Publication:
||Foliage plants -- Effect of cold on -- Florida ( lcsh )
Foliage plants -- Frost damage -- Florida ( lcsh )
||government publication (state, provincial, terriorial, dependent) ( marcgt )
non-fiction ( marcgt )
||Statement of Responsibility:
||Richard T. Poole and Charles A. Conover.
||Florida Historical Agriculture and Rural Life
The publications in this collection do
not reflect current scientific knowledge
or recommendations. These texts
represent the historic publishing
record of the Institute for Food and
Agricultural Sciences and should be
used only to trace the historic work of
the Institute and its staff. Current IFAS
research may be found on the
Electronic Data Information Source
site maintained by the Florida
Cooperative Extension Service.
Copyright 2005, Board of Trustees, University
FACTORS INFLUENCING CHILLING DAMAGE OF FOLIAGE PLANTS
Richard T. Poole and Charles A. Conover
University of Florida, IFAS
Agricultural Research Center Apopka
ARC-A Research Report RH-83-4
The exact mechanism that results in damage to tropical plants when
subjected to chilling temperatures is not known. One theory suggests that
cold water inside the plant, as a result of low temperatures, prevents
normal water utilization with consequent drying of plant cells. This
injury is therefore somewhat similar to drying of tissue at ordinary
temperatures. Conditioning against cold injury involves an increase in
osmotic values of the cell contents which retards the exit of water from
the cell and lessens the stress of reduced temperatures.
As temperatures drop during the fall, an increase in osmotic values
occurs naturally in plants exposed to lowering temperatures and, to a
lesser extent, to plants grown in heated greenhouses. Other methods to
reduce succulent growth and acclimate a plant to cold temperatures include
reductions in water and fertilizer levels.
The experiment described utilized 19 different foliage plants (Table
1) to test potential effects of different water and fertilizer levels
during production on degree of leaf damage when plants were subjected to
350F for 24 or 48 hours.
Cuttings were rooted and potted into 4-inch containers in a potting
medium composed of Florida peat:pine bark:cypress shavings, in a 2:1:1
ratio. Plants were grown 6-8 weeks, April through July, 1981, in a green-
house with 1000 foot-candles maximum. Treatments consisted of 2 fertilizer
levels; (1) 7 lb/y319-6-12 Osmocote, and (2) 7 lb/yd 19-6-12 Osmocote plus
2 lb/100 gal 20-20-20 weekly;and 2 irrigation frequencies of 1 and 2
times/week during production.
All cultivars tested grew well and were well established at the time
they were subjected to chilling temperatures. Plants grown on the
different rates of fertilizer were similar in appearance, while those
receiving the lower watering level of one time/week were slightly smaller
than plants watered twice per week.
Chilling temperatures were obtained by placing plants in standard
packing boxes and placing them in a 350F cooler for 24 or 48 hours. Desired
low temperatures were achieved within boxes after about 2 hours, although
soil temperatures usually remained 1 degree higher than air temperatures
even after 24 hours. After plants were removed from coolers, they were
placed back in the greenhouse where leaf damage was evaluated one week
No chilling injury was observed on Ardisia crenata, Codiaeum
variegatum 'Gold Dust', Hedera helix, Philodendron scandens oxycardium or
Senecio rowleyanus when subjected to 35cF for up to 48 hours (Table 1).
These data are somewhat confusing on Philodendron since we have previously
observed chilling damage on plants subjected to 350 to 400F in the early
fall. However, data for the other non-injured plants is similar to general
reports on these cultivars.
Slight chilling injury was observed on Aeschynanthus pulcher, Dracaena
surculosa, Ficus benjamin, Hoya carnosa and Sansevieria trifasciata
'Laurentii' when subjected to 35F for48 hours, but Dracaena and Ficus were
not injured when they received 35F for24 hours, and also received less
injury at the reduced watering frequency. Dracaena also showed no damage
at the lower fertilizer rate.
Moderate chilling damage occurred on Dracaena marginata 'Colorama'
Peperomia obtusifolia, Peperomia obtusifolia 'Marble', Peperomia obtusifolia
'Variegata' and Plectranthus australis. Except for Dracaena, most injury
occurred on foliage which was not fully expanded. Chilling temperatures for
48 hours produced more damage than 24 hours for all genera in this group.
Increasing the watering level increased damage on Peperomia obtusifolia and
Plectranthus, but had no effect on the other Peperomia cultivars or Dracaena.
Increasing the fertilizer rate increased chilling severity on Dracaena,
but had no effect on the remainder of this group that had moderate chilling
Severe chilling damage was observed on Beqonia x rex-cultorum,
Dracaena deremensis 'Compacta', Dieffenbachia amoena 'Hicolor' and Fittonia
verschaffeltii arqyroneura. General leaf collapse occurred on Begonia and
Fittonia, while on Dracaena a ring of 10 to 15 leaves near the crown was
damaged and turned a gray-black color. The oldest 3 to 4 leaves collapsed
on Dieffenbachia, leaving only 1 or 2 terminal leaves. Increasing the
chilling duration did not affect Begonia but increased damage on the other
genera. Increasing watering frequency increased chilling damage on
Dieffenbachia, Dracaena and Fittonia, but not on Begonia while an increase
in fertilizer level increased chilling damage on all genera.
Of 19 cultivars tested, 12 were chill-damaged by exposure to 350F
for 24 hours and 14 when exposure was increased to 48 hours. Also, severity
of chilling was increased for 10 cultivars when exposed to 350F for 48
rather than 24 hours. Increasing watering level had no effect on 11
cultivars while, on the other 8,severity of chilling damage was increased.
The increase in succulence resulting from higher watering levels probably
made plants more subject to chilling damage. In no case did growth at the
lower watering level increase damage over the higher level.
The higher rate of fertilizer application increased chilling damage
on 6 cultivars while not affecting the other 13. Neither did the lower
fertilizer rate increase chilling damage over the higher rate on any
cultivar tested. As with water, the chilling damage observed at the higher
rate was probably due to succulence of tissue and increased potential for
This experiment was conducted during the late spring and early summer
when plants were growing rapidly and might not be exposed to low, damaging
temperatures when shipped to northern climates. However, results probably
duplicate those that would be obtained when rapidly growing greenhouse plants
would be chilled during any season. Results from this study indicate that
some plants could benefit from less fertilizer and water if they might be
subjected to short durations of cold temperatures, although one should not
forget that wilted plants are usually more severely damaged when subjected
to chilling temperatures.
Table 1. Severity of chilling damage on selected foliage plants at 350F for different
durations when grown on different cultural regimes.
350 temperature Watering freq. Fertilizer rate
Botanical name 24 hr 48 hr I/week 2/week 7 Ib/yd3 7 Ib/yd +
2 lb/100 gal
Begonia x rex-cultorum
S nia obtusifolia
.... iia obtusifolia
++ ++t ++t
++ ++ ++
Chilling damage ratings;
- = No damage (no effect
due to treatment)
+ = Slight damage (damage restricted to less than 10% of leaves)
++ = Moderate damage (damage restricted to less than 50% of leaves)
+++ = Severe damage (damage on 50% or more of leaves)