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
A. R. Chase, L. S. Osborne and R. T. Poole
University of Florida, IFAS
Agricultural Research Center Apopka
ARC-A Foliage Plant Research Note RH-1983-F
Aphelandra squarrosa cultivars are popular foliage plants valued for
their striking dark green and white foliage and yellow flower spikes. They
are commonly called zebra plants due to the characteristic striped foliage.
There are several cultivars produced commercially including the most common,
'Dania',which has dark green foliage with white stripes. The 'Apollo' zebra
plant is also popular with its whitish leaves and green patterns. Red-tinged
cultivars with dark red to violet undersides of leaves are also produced by a
Research has shown that incorporation of 8 Ib/yd of Osmocote 14-14-14
or 2 lb of 20-20-20 soluble fertilizer (per 100 gal applied biweekly to 400 ft2)
improved quality of cuttings being rooted. Fertil zer rates for rooted plants
should be approximately 34 lb nitrogen per 1000 ft2 per year or 200 ppm nitrogen,
75 ppm phosphorus and 150 ppm potassium with each watering.
The best growth of aphelandras is obtained when soil temperatures are
between 70 and 800F with daytime air temperatures up to 900F and a minimum night
temperature of 600F.
Grower experience in Central Florida indicates that flowering of aphelandra
occurs best when plants receive about 1000 ft-c during long summer days and 2500
ft-c during shorter winter days. The higher light levels needed during the
winter may result in some leaf deformity which will be discussed below.
1) Crinkle leaf
Symptoms Leaves crinkled, size reduced, internodes shortened with axillary
bud proliferation. Plants have not responded to any treatments.
Control The disorder is most severe under high light and high temperature.
No bacteria, fungi or viruses have been found associated with this dis-
order and pesticides have no effect. Plants do not respond to micro-
nutrients or proper environmental conditions. Eliminate stock plants with
this problem and maintain proper light levels and temperatures.
2) Ripple leaf
Symptoms Difficult to distinguish from crinkle leaf, but a change of
environment will cause plants to produce healthy leaves.
Control Reduce light to less than 1,500 ft-c and 1,000 ft-c may be necessary
in some situations. Plants grown in low light will have flat leaves and as
light intensity increases, leaves assume more curvature. High
temperature also contributes to ripple leaf.
3) Flowering in propagation bed
Symptoms Tip cuttings produce flower spikes.
Control Reduce light level in propagating area and/or production area.
4) Moisture stress
Symptoms Leaf collapse and occasionally tip collapse.
Control Aphelandra are more susceptible to moisture stress than most
foliage plants. Water frequently and avoid high temperatures.
5) Leaf drop
Symptoms Lower leaves abscise.
Control Maintain proper moisture level, avoid dry air and close spacing
of plants as well as excessive fertilizer applications.
DISEASES OF APHELANDRAS
Aphelandras are subject to several foliar and root or stem diseases caused
by fungal pathogens. Although viral and bacterial pathogens may be involved in
disease situations, these organisms have not been investigated or their roles
described. The most crucial stage for disease development appears to be while
cuttings are being propagated under high moisture conditions. During these
times, even apparently disease-free cuttings may develop leaf spots. Control
measures are complicated by the high water levels which create ideal conditions
for spore germination and wash away fungicide residues. Specific diseases
caused by the most common fungal pathogens are described below.
MAJOR FUNGAL PATHOGENS
1) Botrytis blight (Botrytis cinerea)
Symptoms Botrytis blight appears as large dark green to gray areas found
primarily on leaf edges. The dusty gray-tan spores of the fungus form
readily in this tissue and can be seen with a 10 x hand lens. The affected
leaves generally collapse.
Control Botrytis blight occurs during the cooler, dark months of the winter
and sometimes during the fall. More attention to disease control will be
necessary during these times. Chipco 26019 is registered for Botrytis
blight on this and many other foliage plants and provides excellent control.
2) Corynespora leaf spot (Corynespora cassiicola)
Symptoms Leaf spots start on leaf edges, tips and sometimes centers. They
are dark brown to black and sometimes wet appearing. This disease can be a
serious problem on cuttings rooted under mist or bottom leaves of potted
Control Elimination of overhead water can control this disease. In
situations in which chemicals are needed both maneb compounds and
chlorothalonil (Daconil) provide excellent control. Since the same
pathogen causes a leaf spot of Ficus and lipstick vine, these plants
should be monitored for disease development as well and treated
similarly. Benlate is labeled for disease control on aphelandra.
3) Myrothecium leaf spot (Myrothecium roridum)
Symptoms Leaf spots caused by this pathogen appear similar to those
caused by C. cassiicola when viewed from the upper leaf surface.
Leaf undersides however, generally reveal the presence of the fungal
fruiting bodies which are formed in concentric rings within the dead
spots. These fruiting bodies are irregularly shaped black bodies with
a white fringe and are about the size of a pin head.
Control The same controls apply to Myrothecium leaf spot as Corynespora
leaf spot. Myrothecium leaf spot is most severe when temperatures are
between 70 and 800F and controls should be concentrated during times of
these conditions. Temperatures of 900F greatly inhibit Myrothecium and
make chemical application needless.
4) Phytophthora stem rot (Phytophthora parasitica)
Symptoms Stem rot usually starts at the soil line and causes a blistering
of the stem surface. The lesions are black and slightly mushy and can
extend from the base of the stem up into the petioles of lower leaves.
Complete collapse of the plant is common.
Control Control should be based on use of pathogen-free cuttings, pots
and potting media since the pathogen is easily introduced in any of these
ways. Chemicals which provide control of this disease include Subdue and
Truban although Subdue is the only labeled fungicide of the two.
5) Pythium root rot (Pythium spp.)
Symptoms Pythium root rot is typified by wilting and/or yellowing of the
upper portions of infected plants. Root systems are generally stunted
and have many black mushy roots. The outer portion of these roots can
be easily removed from the inner core. Always obtain an accurate
diagnosis of a root rot disease since it is vital in selection of the
appropriate fungicide for control.
Control Control of Pythium root rot is the same as for Phytophthora stem
PHYTOTOXICITY OF FUNGICIDES ON APHELANDRA
Benlate 50WP Ornalin 50WP
Daconil 4.17 F
Pesticides were tested at recommended
rates and intervals.
MAJOR INSECT AND MITE PESTS
The major arthropod pests of Aphelandra include aphids, mealybugs, mites,
scales and thrips. Mealybug, mite and scale infestations are typically the
result of bringing infested plant material into the greenhouse. Aphids and
thrips have the ability to fly and thus invade the greenhouse from weeds and
other infested plants outside. In the control section for each pest, a few of
the many registered and effective pesticides will be listed. For a complete
listing, please consult the references at the end of this report.
1) Aphids (Green peach and cotton aphids)
Symptoms Aphids are pear-shaped, soft-bodied insects which vary in color
from yellowish-green to dark brown. Infestations frequently go undetected
until honeydew or sooty mold is observed. Aphids can cause distortion of
new growth or, in extreme cases, infested plants will be stunted.
Control There are a number of materials that will control aphids.
2) Mealybugs (Long-tailed and solanum mealybugs)
Symptoms Mealybugs appear as white cottony masses in leaf axils, on the
lower surfaces of leaves and on the roots. Honeydew and sooty mold are
often present, and infested plants become stunted and, with severe
infestations, plant parts begin to die.
Control Systemic materials are preferred. Examples of chemicals which have
systemic activity are: Dimethoate, Disyston, Metasystox-R and Orthene.
Bendiocarb, Enstar 5E and Mavrik appear to be as effective as some of the
3) Mites (Broad mite and false spider mites)
Symptoms Mites are very small and go unnoticed until plants become severely
damaged. Broad mites cause foliar necrosis of the vegetative shoot apex.
Initial symptoms of injury show new leaves cupped downward, puckered,
stunted and have serrated margins. False spider mites (Brevipalpus spp.)
are red in color and sedentary. Initial infestations are indicated by
faint brown, scruffy flecks, later becoming bronze or reddish in color.
Basal leaf areas are affected, vegetative shoot apexes may be killed, and
severe leaf drop may occur.
Control Mites can be controlled with Kelthane, Pentac or Vendex. The
critical point in any control program is thorough coverage with the
pesticide. The best control program is to minimize the possibility of
introducing mites into the growing area on infested plant material.
4) Scales (Hemispherical and green scales)
Symptoms Infested plants become weakened or stunted and begin to die.
Scales can be found feeding on leaves, petioles or stems. Their shape,
size and color are variable and many are hard to distinguish from the
plant material on which they are feeding.
Control See Mealybugs
(Banded greenhouse thrips)
Symptoms Infested leaves become curled or distorted, with silver-gray
scars or calloused areas where feeding has occurred.
Control Many materials are registered and effective at controlling thrips.
PHYTOTOXICITY OF INSECTICIDES AND MITICIDES ON APHELANDRAS
Safer's Agro-Chem Insecticidal
Pesticides were tested at recommended rates and intervals.
1. Chase, A. R. 1983. Phytotoxicity of some fungicides used on tropical
foliage plants. ARC-Apopka Research Report, RH-83-2.
2. Short, D. E. 1978. Phytotoxicity of insecticides and miticides to
foliage and woody ornamental plants. Extension Entomology Report #57.
3. Short, D. E., L. S. Osborne, and R. W. Henley. 1982. 1982-83 Insect and
related arthropod management guide for commercial foliage and woody plants
in Florida. Extension Entomology Report #52.
4. Simone, G. W. 1982. Disease control pesticides for foliage production-
1982. Extension Plant Pathology Report #30.
Mention of a commercial or proprietary product or of
does not constitute a recommendation by the authors,
tration under FIFRA as amended.
a pesticide in this paper
nor does it imply regis-
5) Thri ps