Group Title: AREC-A foliage plant research note - Agricultural Research and Education Center-Apopka ; RH-85-A
Title: Cordyline
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Permanent Link: http://ufdc.ufl.edu/UF00065996/00001
 Material Information
Title: Cordyline
Series Title: AREC-A foliage plant research note
Physical Description: 7 p. : ; 28 cm.
Language: English
Creator: Osborne, L. S
Conover, Charles Albert, 1934-
Chase, A. R ( Ann Renee )
Agricultural Research and Education Center (Apopka, Fla.)
Publisher: University of Florida, IFAS, Agricultural Research and Education Center-Apopka
Place of Publication: Apopka FL
Publication Date: 1985
 Subjects
Subject: Cordyline -- Growth -- Florida   ( lcsh )
Cordyline -- Diseases and pests -- Control -- Florida   ( lcsh )
Genre: government publication (state, provincial, terriorial, dependent)   ( marcgt )
bibliography   ( marcgt )
non-fiction   ( marcgt )
 Notes
Bibliography: Includes bibliographical references (p. 7).
Statement of Responsibility: L.S. Osborne, C.A. Conover, and A.R. Chase.
General Note: Caption title.
 Record Information
Bibliographic ID: UF00065996
Volume ID: VID00001
Source Institution: University of Florida
Rights Management: All rights reserved by the source institution and holding location.
Resource Identifier: oclc - 71193540

Full Text





HISTORIC NOTE


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
(EDIS)

site maintained by the Florida
Cooperative Extension Service.






Copyright 2005, Board of Trustees, University
of Florida








Cordyline (Ti Plant)

L. S. Osborne, C. A. Conover and A. R. Chasel

University of Florida, IFAS
Agricultural Research and Education Center Apopka
EAREC-A Foliage Plant Research Note RH-1985-A
HUME LIBRARY
Cordyline terminalis (Ti, Hawaiian goo -luck plant) and its cultivars are
popular indoor foliage plants. These plant are ^'obla 'i31d to p provide a
touch;of color to otherwise green groupings Cordyline terminalis,, the
species, is entirely green and most consume rpreIer the colorful ciltivars.
Cordyline teminalis 'Baby Doll', a small- lae t TiA;V9 QfrWCiff~at n, rose and
green leaves, is probably sold in greatest number, 6u is most ofteA found in
dish gardens or small pots. Cordyline terminalis 'Eugene Andre', a maroon and
rose cultivar, and 'Firebrand', a deep reddish cultivar, are larger plants.
Some of the.interesting multicolor plants include Cordyline terminalis'
'Amabilis', Baptisti', 'Imperialis' and 'Tricolor'. Some larger ,cultivars in
the trade include, Cordyline terminalis 'Kiwi', 'Nagi' and 'Schubertii', and are
sold in pot s-i-es from 6 to 17 inches.

Light levels-can affect appearance of multicolored Ti cultivars. Plants
grown in excessive shade will have dull colors with increased amounts of green
coloration. Suggested shade level is 63 to 73%, about 3000 to 3500 ft-c which
will produce-plants with good coloration. Excellent growth can be obtained
with a fertilizer regime that provides 1500 lb N/A/yr from a 3-1-2 ratio
fertilizer source; liquid or slow-release (equivalent to approximately 34 lb N,
12 lb P20 and 23 lb K 0/1000 ft /yr). Where plants are subject to heavy rain-
fall or frequent irrigations, the fertilizer level may need to be increased by
15 to 25%.

Potting media utilized for Ti plant should be of good quality, and provide
excellent aeration and water-holding capacity. Amendments s would include a low
to moderate level of micronutrients such as 1 lb Micromax/yd and sufficient
dolomite to adjust medium pH to 5.5 to 6.5. The higher pH has been shown to be
beneficial in reducing fluoride toxicity. Suggested, air temperatures for best
growth are 650F minimum to 950F maximum. Cordyline can tolerate low and high
temperatures, but growth rate will be reduced.
PHYSIOLOGICAL PROBLEMS

1) Fluoride Toxicity

Symptoms The first indication of fluoride toxicity on Cordyline is
tipburn followed by marginal necrosis. In severe cases, mottling also
occurs within the center of the leaf and the entire leaf may die.
Cordyline terminalis 'Baby Doll' is the most susceptible cultivar to


1Assistant Professor, Entomology; Professor, Ornamental Horticulture and Center
Director; and Associate Professor, Plant Pathology, Agricultural Research and
Education Center, 2807 Binion Road, Apopka, FL 32703, respectively.








this problem, although all cultivars have been observed to have symptoms
when fluoride is present in water, soil or fertilizer.

Control Where fluoride is known to be a problem, the propagation and
potting media should have a pH of 6.0 to 6.5 to reduce fluoride availa-
bility. Cuttings without roots are likely to take up large amounts of
fluoride. Some producers utilize treated water in propagation areas to
prevent fluoride uptake during rooting and nontreated water after
rooting. To reduce fluoride uptake, use potting media, irrigation water
and fertilizers low in fluoride content. Irrigation water should contain
less than 0.25 ppm fluoride.

2) Poor Color

Symptoms Cordyline is popular because it provides various shades of
purple, maroon, rose, pink and yellow, as well as green. Intensity
(brightness) of any of the colors, except green, under some environmental
conditions may be so poor that plants appear dull. Plants also may be
mostly dark purple or maroon without highlights of rose or pink common to
the cultivar.

Control Color intensity appears to be controlled by temperature, light
and fertilizer levels. Levels of carbohydrates are low during summer
when night temperatures are high and poor color often occurs during this
period. Low light intensity, especially during summer, and high ferti-
lizer levels also reduce color intensity. Best color intensity will
occur during the period November through May, if suggested light and
fertilizer levels are utilized. During periods of poor coloration, some
improvement can often be obtained by increasing light intensity and
reducing temperature.

3) Damage to terminal growing point

Symptoms Growing point appears to die or partially collapses, but
eventually regrows.

Control This symptom usually occurs after application of a "leaf shine"
compound or excess fertilizer which collects in the growing point. Care
must be taken to prevent accumulation within the growing point of
potentially toxic substances and liquid fertilization should be followed
with a few minutes of only water.
DISEASES OF CORDYLINE

Cordyline spp. are affected by numerous bacterial and fungal diseases
which damage leaves, stems.and roots. Diseases caused by fungi are the most
common and variable. Several other diseases, other than those listed below,
have been described on Ti plant, but are not included since they do not
commonly occur in Florida.








BACTERIAL DISEASES


1) Erwinia blight (Erwinia chrysanthemi, E. carotovora pv. carotovora)

Symptoms Systemic infections of Cordyline cuttings with one or both
species of Erwinia are common. These infections result in a combination
of symptoms including a wet, mushy leaf spot and stem rot. Lesions on
leaves and stems are usually water-soaked and slimy and eventually dis-
integration occurs. Severe infections can result in cutting loss, since
the plants often rot from the cutting end upwards. If these cuttings are
carefully recut to remove the rotten portion of the stem and restuck,
they will sometimes root adequately. The unfortunate fact, however, is
that most of the cuttings will then develop symptoms of stem and root rot
caused by Erwinia. Erwinia root rot appears similar to other root
diseases with the roots water-soaked and black. Complete disintegration
of the infected root system often occurs.

Control There are no chemical controls which provide an appreciable
degree of symptom relief for any of the phases of Erwinia blight. As
mentioned earlier, recutting diseased material only postpones the loss
of that material and increases the chances of infection of other healthy
material. Carefully examine all cuttings used for propagation, destroy-
ing those which are suspected of Erwinia blight. Always use pathogen-
free plants for stock as well.

FUNGAL DISEASES

1) Fusarium leaf spot (Fusarium moniliforme)

Symptoms Fusarium leaf spot of Cordyline appears similar to the same
disease of dracaenas. Lesions appear only on the immature leaves near
the growing tip. Spots are tan to reddish-brown and roughly ellipsoid
in shape. In severe cases, the lesions coalesce and become very large
and irregularly shaped. A bright yellow halo sometimes surrounds
lesions.

Control Minimize water applied to plant foliage. If the leaves are kept
relatively dry, the disease will not occur. Under overhead irrigation,
fungicides may be necessary. Benlate is registered for use on ornamen-
tals and will control this disease. Other chemicals, which provide
disease control not currently registered for use on this plant, are
Daconil and Chipco 26019 which also provide disease control.

2) Fusarium stem and root rot (Fusarium sp.)

Symptoms Fusarium stem and root rot is caused by a different species of
Fusarium than the one causing the leaf spot disease. Initial symptoms
include yellowing of the lower leaves and slight wilting. Examination
of the root systems reveal blackened water-soaked roots which greatly
resemble those infected with Erwinia spp. Stem lesions also appear near
the potting medium. Lesions are sunken, tan and wrinkled. They some-
times contain the yellowish spores of the pathogen in powdery masses.









Control Chemical control of this disease may be achieved with use of
Benlate applied as both a foliar spray and a drench. Minimizing water
applications and growing pathogen-free plants in pathogen-free potting
medium should be attempted. Since the disease spreads through irrigation
water, keep plants on wire benches or other structures which reduce the
chances of drainage water contaminating other pots. Always remove and
destroy symptomatic plants as soon as they are found.

3) Phyllosticta leaf spot (Phyllosticta dracaenae)

Symptoms Lesions are circular to slightly irregular and range from 1 to
5 mm in diameter. They appear mainly on the older leaves of plants and
are usually tan with purple borders and yellow halos. Under conditions
of high disease pressure, the lesions may coalesce and the entire leaf
may die.

Control Spray applications of either Manzate or Daconil can control this
disease on Cordyline, but only'Manzate is registered for this plant at
this time. The cultural controls listed for Fusarium leaf spot will also
aid in control of this leaf spot disease.

4) Phytophthora leaf spot (Phytophthora parasitica)

Symptoms Lesions form mainly on lower leaves close to the potting medium.
They are initially water-soaked, brown, zonate areas with irregular
margins. Similar diseases caused by this pathogen also occur on
schefflera, spathiphyllum, dieffenbachia and philodendron.

Control This disease is usually easy to avoid if plants are grown on
raised benches away from the native soil. Splashing water from the
native soil on to the lower leaves is the mode of infection. Soil
drenches with Truban or Subdue will reduce chances for infection but are
not currently registered for use on this plant.

5) Southern blight (Sclerotium rolfsii)

Symptoms Southern blight disease appears much the same on one host as
another. The pathogen generally attacks the crown of the plant first,
sometimes leaving the roots intact and causing girdling and collapse of
the tops only. Sclerotia, the fruiting bodies of the pathogen, form all
over the infected tissue and appear as small mustard seed-sized bodies.
They are first white and turn brown as they mature. The white fan-like
mycelium of the pathogen also forms over the plant, potting medium and
even sides of benches.

Control Chemical control of Southern blight is difficult since the only
fungicide which is effective also stunts most plants severely. Since
Terraclor can only be used once a year, its application is generally made
as an emergency procedure instead of a preventive measure. Always
discard plants suspected of Southern blight infection and use pathogen-
free potting media and pots since the organism lives in soil and can
transfer from one crop to the next on recycled materials and equipment.








PHYTOTOXICITY OF FUNGICIDES FOR CORDYLINE

SAFE

Benlate 50WP Fungo 50WP
Chipco 26019 Maneb compounds
Copper compounds Ornalin 50WP
Daconil 4.17F
Daconil 75WP
Fungicides were tested at recommended
rates and intervals.


INSECT AND MITE PESTS OF CORDYLINE

The major arthropod pests of C. terminalis include fungus gnats, mealy-
bugs, mites, scales, and thrips. Mealybug, mite, and scale infestations are
typically the result of introducing infested plant material into the green-
house. Fungus gnats 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) Fungus Gnats

Symptoms Small black flies are observed running around the soil surface
or on leaves. The larvae are small legless "worms" that inhabit the
soil. Larvae spin webs on the soil surface which resemble spider webs.
Damage is caused by larvae feeding on roots, root hairs, and lower stem
tissues. Feeding damage may predispose plants to disease and dense
populations of this insect are often found in association with diseased
plants.

Control Reduce the amount of water applied to each pot where possible.
Soil drenches, soil-surface sprays of Diazinon or Vydate 2L or applica-
tion of oxamyl granules effectively control the larvae.

2) 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, infested plants become stunted and, with severe infesta-
tions, the plant will die.

Control Systemic materials are preferred. Examples of chemicals which
have systemic activity are: Dimethoate, Disyston, Metasystox-R, and
Orthene. Bendiocarb (Dycarb, Ficam, Turcam) appears to be as effective
as some of the systemic materials. Control of root mealybugs is
accomplished with an insecticide soil drench. Diazinon and Vydate are
the only insecticides registered for this purpose, but both can cause
phytotoxicity. When pesticides are applied to the soil, care must be
taken to assure that the pots have good drainage and that no saucers are
attached or phytotoxicity may result.









3) Mites


Symptoms Twospotted spider mites are the major pest of C. terminalis
and often go unnoticed until plants turn yellow or become speckled due
to the feeding of this pest. Webbing, loss of leaves and plant death
can occur when mite populations reach high levels.

Control Mites can be controlled with Kelthane, Mavrik, 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 (Florida red scale)

Symptoms Infested plants become weakened or stunted and then 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. The Florida red scale is the major
scale pest of this plant. It is an armored scale that is reddish-brown
to black in color. Feeding by this insect causes a characteristic
yellow or chlorotic streak that radiates from the point of attachment.

Control See Mealybugs.

5) Thrips

Symptoms Infested leaves have silver-gray scars or calloused areas where
feeding has occurred.

Control Many materials, such as Dycarb, Mavrik and Orthene, are
registered and effectively control thrips.

Phytotoxicity data for this plant are limited. Therefore, a small group
of plants should be tested for phytotoxicity prior to treating the entire crop
(see Chase et al. 1981).








References

1. Chase, A. R. 1983. Phytotoxicity of some fungicides used on tropical
foliage plants. ARC-Apopka Research Report, RH-83-2.

2. Chase, A. R., T. J. Armstrong, and L. S. Osborne. 1981. Why should you
test pesticides on your plants? ARC-Apopka Research Report, RH-81-6.

3. Short, D. E. 1978. Phytotoxicity of insecticides and miticides to foliage
and woody ornamental plants. Extension Entomology Report #57.

4. Short, D. E., L. S. Osborne, and R. W. Henley. 1983. 1983-84 Insect and
related arthropod management guide for commercial foliage and woody plants
in Florida. Extension Entomology Report #52.

5. Simone, G. W. 1983. Fungicides for use on ornamentals 1983-84. Extension
Plant Pathology Circular 484-B.


Mention of a commercial or proprietary product or of a pesticide in this paper
does not constitute a recommendation by the authors, nor does it imply regis-
tration under FIFRA as amended. Pesticides should be applied according to
label directions. Those pesticides listed in the control sections for each
disorder, but not listed in the phytotoxicity charts, HAVE NOT been tested for
plant safety at the University of Florida.




i




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