Potho Production Guide
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CFREC-A Foliage Plant Research Note RH-1991-29
R.T.
Poole, A.R. Chase and L.S. Osborne
University of Florida, IFAS
Central Florida Research and Education Center - Apopka
2807
Binion Rd., Apopka, FL 32703-8504
POTHOS
This plant must have a criminal background, it has so many
aliases. Exotica and Tropica show pictures of several Scindapsus
and Epipremnum species and Hortus III also lists species
of Scindapsus and Epipremnum. Sales catalogs
feature names like Devil's Ivy and Golden Pothos. The current
name is Epipremnum aureum (alias Scindapsus aureus
alias Pothos aureus). `Golden Pothos' is a golden,
yellow-green variegated vine with waxy leaves. When grown in
optimum conditions, such as the tropics, leaves will grow to two
feet in length. `Marble Queen' has smooth waxy leaves with white
variegation. A third "Pothos" is still botanically
described as Scindapsus. Scindapsus pictus usually goes by
the name of Pictus and has thick leatherlike leaves, obliquely
ovate, dark green with green-silver blotches.
PRODUCTION
Stocks plant are best grown at 5,000 foot-candles (ft-c).
Number of cuttings and weight of cuttings are larger than those
from stock plants grown at 2,000 ft-c. Pothos cuttings will have
rapid shoot and root growth if light is 3,000 ft-c and the
temperature is 80°F. Rooting occurs within 3-4 weeks and buds
can start to grow in 1-2 weeks. There was no benefit from
indolebutyric acid (IBA). Cuttings can be stored at 50-65°F, but
they should be placed in the mist bed as soon as possible.
Cuttings will root equally well in an organic medium such as peat
or an inorganic medium such as calcined clay.
Pothos will survive a wide range of environmental conditions,
but grows best at 70- 90°F. Minimum temperatures below 70°F and
maximum temperatures above 90°F will greatly retard growth.
Plants should be supplied the equivalent of 5 lbs of
nitrogen/1000 ft2 monthly from a 3-1-2 analysis or 7 grams of
19-6-12 per 6" pot per 3 months. Slow release and liquid
have been successfully used. Micronutrients such as copper, iron,
manganese and zinc are needed in such small quantities that the
impurities in water and micronutrients supplied by the medium are
usually sufficient. Tissue composition of good quality foliage
plant has been found to be: N, 2.5-3.5% dry weight; P,
0.20-0.35%; K, 3.0-4.5%; Ca, 1.0- 1.5% and Mg, 0.3-0.6%. The
growing mix should be well aerated and overwatering avoided.
Pothos have been watered with sewage effluent with no harmful
effect. Plants growth is modified easily with the growth
retardants B-Nine at 10,000 parts per million (ppm) spray and 100
ppm of an ancymidol (A-REST) spray or 0.6 milligrams (mg) of
ancymidol per square foot and 100 mg per 600 milliliter pot of
paclobutrazol (Bonzi).
Pothos are very tolerant of atmospheric fluoride and ethylene
(C2H4) and can be shipped for 2 weeks without loss of quality if
temperatures are maintained between 55-60°F. Pots containing
pothos with an electrical conductivity (EC) range of 1,000 -
6,000 mhos/cm as determined by the pour-through method maintained
an attractive appearance for 6 weeks after placement in rooms
with 125 ft-c for 12 hours daily. While indoors plants should be
watered 1 - 2 times weekly.
PHYSIOLOGICAL PROBLEMS
- 1) Loss of variegation
- Symptoms -
- Stock plants begin to lose variegation with leaves
becoming predominantly green.
- Control -
- Frequently cutters remove the most desirable vines for
propagation, leaving poorly variegated vines to expand.
To maintain best leaf color in the stock beds, cut above
a node with a leaf of the proper variegation. Occasional
rouging of undesirable vines maintains desirable
variegation. Light intensities of less than 1000 ft-c
also contributes to loss of variegation.
2) Discolored leaves
- Symptoms -
- Leaves have scattered brown patches, usually located in
the center of the leaf.
- Control -
- Low temperatures or abrupt change from very high
temperatures to moderate temperatures can cause this
discoloration, especially if plants are succulent and
growing vigorously. Maintain even, warm temperatures.
3) Small leaves
- Symptoms -
- New growth produces medium size to small leaves.
- Control -
- This phenomenon, caused by lack of fertilizer and/or low
light, rarely occurs in the nursery and can be controlled
by fertilizer application and increased light.
4) Decaying roots
- Symptoms -
- Roots brown or nonexistent.
- Control -
- If not caused by pathogens, reduce irrigation frequency
and/or improve aeration of the soil mix.
BACTERIAL PROBLEMS
Reference Pest Control Guides Here
1) Bacterial leaf spot - (Pseudomonas cichorii,
Erwinia carotovora, and E. chrysanthemi)
- Symptoms -
- Bacterial leaf spot diseases are characterized by
rapidly spreading water- soaked lesions formed anywhere
on the leaves. Under wet conditions, the centers of these
spots may fall out. Sometimes leaf spots have a yellow
border.
- Control -
- Bacterial leaf spot can be controlled through
elimination of water on leaves. This is almost impossible
during rooting of cuttings and preventative applications
of streptomycin sulfate (Agri-Strep 21.2%) may aid
control. Choice of clean cuttings and strict sanitation
are probably the most important control measures.
2) Cutting soft rot - (Erwinia carotovora and
E. chrysanthemi)
- Symptoms -
- A mushy soft rot of the lower end of a cutting.
Sometimes the plants have a fishy, rotten odor,
characteristic of Erwinia infections.
- Control -
- Same as above except use of bactericides is not
recommended due to very poor efficacy.
FUNGAL PROBLEMS
Reference Pest Control Guides Here
1) Pythium root rot (Pythium splendens)
- Symptoms -
- Cuttings usually show poor rooting and have yellow
leaves. Examination of the stem and roots reveals a mushy
black rot extending from the cut end into the upper
portions of the stem and leaves. Root and stem rots
usually occur in patches on a propagation bench where it
spreads into uninfected cuttings.
- Control -
- Control should be based on use of disease-free
propagation material, sterilized potting media and raised
benches. Reducing water applications to the minimum level
for good rooting also reduces root and stem rot diseases.
2) Rhizoctonia foot rot (Rhizoctonia solani)
- Symptoms -
- A mass of brownish mycelium covers the infected plants.
Growth of mycelium from the potting medium onto the plant
can escape notice and give the appearance that plants
have been infected from an aerial source of inoculum.
Close examination, however, generally reveals the
presence of mycelium on stems prior to development of
obvious symptoms. Rhizoctonia mycelia are usually
reddish-brown in color and have the consistency of a
spiderweb.
- Control -
- Chemical control of diseases caused by Rhizoctonia has
been investigated on many plants using a variety of
fungicides.
3) Southern blight (Sclerotium
rolfsii)
- Symptoms -
- The pathogen attacks all portions of the plant, but is
most commonly found on stems and leaves. Initially,
symptoms on stems are confined to water-soaked, necrotic
lesions at or near the soil line. White, relatively
coarse mycelium grow in a fan-like pattern and may be
seen on the soil surface, leaves or stems. The round
sclerotia form almost anywhere on the affected portions
of the plant or the soil surface. They are initially
white and cottony and approximately the size of a mustard
seed. As sclerotia mature, they turn tan and eventually
dark brown and harden. Mycelia and sclerotia generally
develop concurrently with stem rot and wilting, allowing
an accurate diagnosis of the problem. A cutting rot can
develop on contaminated plant materials during the summer
months.
- Control -
- Although this disease can be avoided using proper
cultural methods, it continues to cause losses in
production of foliage plants today. Chemical control of
Southern blight has been investigated on several
different foliage plants as well as non-ornamental crops.
INSECT AND RELATED PROBLEMS
Reference Pest Control Guides Here
Insects and mites are seldom serious problems on
Pothos. The major arthropod pests include caterpillars,
mealybugs, mites, scales and thrips. Mealybug, mite and
scale infestations are typically the result of bringing
infested plant material into the greenhouse. Moths 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) Caterpillars (worms)
- Symptoms -
- Infestations are easy to detect because worms, their
excrement and the damage they cause, are usually quite
visible to the unaided eye. Damage appears as holes in
the center or along the edges of leaves. Damage by worms
is often confused with slug or snail damage. The only way
to determine which pest is involved is to find a
specimen. Old damage can be distinguished from new by the
calloused appearance of the older damaged areas (worms
are usually gone by this time).
- Control -
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 and infested
plants become stunted, and with severe infestations,
plant parts begin to die.
- Control -
- Systemic materials are preferred. Control of root
mealybugs is accomplished with soil drenches with an
insecticide. 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 -
- Spider mites are very small and go unnoticed until
plants become severely damaged. Damaged foliage begins to
turn yellow or become speckled due to the feeding of
mites. Webbing, loss of leaves and plant death can occur
when mite populations reach high levels. Often the
presence of this pest is overlooked because the cast
skins and webbing produced by this mite are confused for
dust on undersides of leaves. Mites have round pale
yellow to reddish eggs deposited on the under surfaces of
leaves; nymphs and adults have two dark patches on either
side of there bodies or they are brick red in color
depending on the species.
- Control -
- 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. Biological
control programs have worked in small scale studies but
remain unproven in commercial greenhouses.
4) Scales
- Symptoms -
- Infested plants become weakened or stunted and begin to
die. Scales can be found feeding on leaves, petioles, or
stems. They are usually distinct from the plant material
on which they are feeding. Their shape (round to oval),
size (pinpoint to 2 mm long), and color (light to dark
brown) are quite variable and many scales are hard to
distinguish from the plant material on which they are
feeding.
- Control -
- See Mealybugs
5) Thrips
- Symptoms -
- Thrips are small (less than 1/20), thin insects. Adult
thrips can be identified by a long fringe of hair around
the margins of both pairs of wings. Color varies between
species with western and other flower thrips being yellow
to light brown and banded greenhouse thrips and a few
other thrips that feed mainly on leaves being dark brown
to black. Feeding takes place with rasping type mouth
parts. Infested leaves become curled or distorted, with
silver-gray scars or calloused areas where feeding has
occurred. Thrips can transmit the tomato spotted wilt
virus to many different ornamentals. Any unusual symptoms
should be investigated.
- Control -
- Many materials are registered and effective at
controlling thrips.
Reference Pest Control Guides Here
Pesticides should be applied according to label directions.
Regardless of the pesticide or mixture of pesticides used, it
is
strongly recommended that the effects be evaluated on a few
plants, under your particular conditions before treating all
plants.
Mention of a commercial or proprietary product in this paper
does not constitute a recommendation by the authors,
nor does it imply registration under FIFRA as amended.
REFERENCES
1. Chase, A.R. 1990. Phytotoxicity of bactericides and
fungicides on some ornamentals -1990 update. Nursery Digest
24(5)11.
2. Chase, A.R. and R.T. Poole. 1990. Effect of variegation on
growth and chilling sensitivity of `Marble Queen' pothos.
CFREC-Apopka Research Report RH-90-17.
3. Conover, C.A. and R.T. Poole. 1984. Use of sewage effluent
as an irrigation source for foliage plants. AREC-A Research
Report RH-84-17.
4. Conover, C.A. and R.T. Poole. 1984. Influence of shipping
temperature and duration on simulated shipping of small potted
foliage plants. Proc. Fla. State Hort. Soc. 97:280-282.
5. McConnell, D.B. and R.T. Poole. 1972. Vegetative growth
modification of Scindapsus aureus by ancymidol and PBA.
Proc. Fla. State Hort. Soc. 85:387-389.
6 Poole, R.T. and C.A. Conover. 1982. Growth of foliage
plants at various night temperatures. CFREC-Apopka Research
Report RH-82-26.
7. Poole, R.T. and C.A. Conover. 1987. Heat stress of foliage
plants. CFREC-Apopka Research Report RH-87-2.
8. Poole, R.T. and C.A. Conover. 1988. Storage of
Philodendron and Pothos cuttings. Proc. Fla. State Hort. Soc.
101:313-315.
9. Short, D.D. 1978. Phytotoxicity of insecticides and
miticides to foliage and woody ornamental plants. Extension
Entomology Report #57.
10. 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.
11. Simone, G.W., and A.R. Chase. 1989. Disease control
pesticides for foliage production (Revision 4). Plant Protection
Pointer. Extension Plant Pathology Report #30. [also in Foliage
Digest 12(9):1-8]
12. Wang, Ying-Tung. 1987. Effect of warm medium, light
intensity, BA and parent leaf on propagation of Golden Pothos.
HortScience 22(4):597-599.