Programs for the foliage plant industry
Full Citation
Permanent Link: http://ufdc.ufl.edu/UF00074490/00001
 Material Information
Title: Programs for the foliage plant industry
Series Title: CFREC-Apopka research report
Physical Description: v. : ; 29 cm.
Language: English
Creator: University of Florida -- Institute of Food and Agricultural Sciences
Central Florida Research and Education Center--Apopka
Publisher: Agricultural research Center.
Place of Publication: Apopka Fla
Creation Date: 1985
Frequency: annual
Subjects / Keywords: Foliage plant industry -- Florida   ( lcsh )
Genre: government publication (state, provincial, terriorial, dependent)   ( marcgt )
serial   ( sobekcm )
General Note: Description based on: 1987; title from cover.
 Record Information
Source Institution: University of Florida
Rights Management: All rights reserved by the source institution and holding location.
Resource Identifier: oclc - 71815908
lccn - 2006229353
System ID: UF00074490:00001

Full Text
I .Central Florida Research and Education
87-7 Center -.Apopka

for the


Institute of Food and Agricultural Sciences
University of Florida, Gainesville
Central Science
OCT of Forida 987
University of Florida


A. R. Chase, C. A. Conover, R. W. Henley, R. J. Henny,
L. S. Osborne and R. T. Poole

University of Florida, IFAS
Central Florida Research and Education Center-Apopka
CFREC-Apopka Research Report RH-87-7



Production Technology
Physical Environment
Light and Fertilizer Recommendations for Production of
Acclimatized Potted Foliage Plants 5
Chemical Environment
Relationships of Soluble Salts Levels to Fertilization Levels
and Foliage Plant Quality 9
Pest Management
Evaluation of Sweetpotato Whitefly as a Pest of Tropical
Ornamental Foliage Plants 11
Biological Control of Pests Attacking Ornamental Foliage Plants
in Florida 13
Dip Treatment of Tropical Ornamental Foliage Cuttings in
Fluvalinate to Prevent Spread of Insect and Mite Infestations 16
Effect of Chlorpyrifos and Pythium splendens on Growth of Rex
Begonia 18
Plant Pathology
Cylindrocladium Petiole and Root Rot of Spathiphyllum 20
Descriptions of New Bacterial Diseases of Foliage Plants 21
Effect of Cycocel on Diseases 22
Effect of Fertilizer Level on Bacterial Diseases of Foliage Plants 23
Temperature Effects on Rhizoctonia Aerial Blight of Boston Fern 25
Plant Improvement
Aglaonema, Dieffenbachia and Anthurium Breeding 26
Postproduction Technology
Shipping and Handling
Factors Affecting Dracaena 'Massangeana' Leaf Discoloration 27
Factors Influencing Shipping of Acclimatized Foliage Plants 29
Utilization Technology
Floor Cleaners and Foliage Plants 35
Response of Foliage Plants to Commercial Interior Paints 36
Cultural and Pest Control
Evaluate the Problem of Monomorium pharaonis Infested Ornamental
Plants in Interior Landscapes and Develop Control Measures 37


As Florida's foliage plant industry developed during the mid-1960's, many
problems developed which tended to limit industry success. It was these
problems which caused some Central Florida nursery leaders to request a
research station with faculty to work on their unique problems. They arranged
for Orange County to purchase the 18-acre tract, which is now the site of the
Central Florida Research and Education Center, and donate it to the State. By
1965 funds were appropriated by the State Legislature to build an office
building, greenhouse and storage building and an additional appropriation was
made in 1968 to operate the new unit which was initially designated the Ridge
Ornamental Horticultural Laboratory, a unit of the University of Florida's
Institute of Food and Agricultural Sciences.

Initial research at the Ridge Ornamental Horticultural Laboratory, with
three faculty members, focused on propagation, plant pathology, potting mixes
and chemical weed control. A foliage extension specialist, entomologist and
plant breeder were added later to provide more comprehensive coverage of
problems facing the industry.

In 1979, the Agricultural Research Center-Apopka, as it was then called,
expanded its commodity responsibility to the cut foliage industry with the
addition of a research-extension faculty position to study some of the
problems of the cut florist greens industry in Florida. Research on
nutrition, weed control, cold protection and post-harvest handling continues
to be major thrusts of this program. 4

Today, Florida's foliage plant nursery industry produces plants valued at
over 300 million dollars wholesale per year, which is over 20 times the size
of the industry when the research center opened in 1968. Most of the plants
produced in Florida are exported to other states and many foreign countries.
Although technology has improved markedly over the years, there are still many
challenges which must be met if the industry is to remain healthy. Foliage
plant research emphasis has expanded from strictly production elements to
other factors which alter the quality of plants during shipping, handling,
retail display and maintenance in commercial interiorscape accounts. One of
the greatest industry challenges of the next few years will be to sustain
foliage plant research at a level which will assure that Florida's foliage
plant industry retains a competitive edge in the market- place.


The Central Florida Research and Education Center-Apopka consists of a
office building which also houses faculty, the plant pathology laboratory,
library, and conference room. Other facilities include three other laboratory
buildings, seven greenhouses, six shadehouses for cut foliage, one shadehouse
for potted foliage plants, and four other buildings used for maintenance and
storage. A facilities diagram and key are provided below.

I 15



13 17

12 11

6 8

L -. __ __ ___,,,, -._. ,

R 20




Office-Conference Building and Pathology Laboratory
Pathology Greenhouse
Physiology and Breeding Greenhouse
Entomology Greenhouse
Pathology Greenhouse
Physiology Greenhouse
Breeding Greenhouse
Physiology and Fern Laboratory
Plant Tissue Culture and Breeding Laboratories
Entomology Laboratory
Spaceframe Shadehouse
Postharvest Physiology Building
Acclimatization Building
Breeding, Entomology and Physiology Greenhouse
Pesticide Storage Building
Storage Building
Maintenance Building
Vehicle Building




- "




There are presently seven faculty positions at Central Florida Research
and Education Center-Apopka. Their names and area of specialization are as

Dr. Charles A. Conover Professor, Ornamental Horticulturist and Center
Director Administration, Soils and Nutrition
Dr. Ann R. Chase Assoc. Professor, Plant Pathologist Ornamental Plant
Dr. Richard W. Henley Professor, Ornamental Horticulturist Foliage
Plants, Extension and Research
Dr. Richard J. Henny Assoc. Professor, Plant Geneticist Foliage Plant
Dr. Lance S. Osborne Assoc. Professor, Entomologist Insect and Nematode
Pests of Ornamentals
Dr. Richard T. Poole, Professor, Plant Physiologist Horticulture and
Physiology of Ornamentals
Dr. Robert H. Stamps Asst. Professor, Ornamental Horticulturist Cut
Foliage, Research and Extension

The research and extension programs are supported by a very well
qualified staff of secretaries, biological scientists and agricultural
technicians, a total of support personnel.

Correspondence with research or extension faculty regarding completed
project or extension publications should be addressed to: Central Florida
Research and Education Center Apopka, 2807 Binion Road, FL 32703.
Telephone number 305/889-4161.

Each faculty member is involved with a number of different research
projects at any given time. The following are a few reports from
projects which have been completed during the past two years. In some
cases, research on the project areas mentioned in this publication are



Investigators: C. A. Conover and R. T. Poole

Acclimatized foliage plants have become the standard of the
industry and have increased consumer acceptance of interior plants with
their increased tolerance of interior environments. Although numerous
factors influence acclimatization, the most important factor during
production of foliage plants are light intensity and fertilization

Light Light acclimatization is not beneficial to all plants because
physiological responses to light can be divided into three categories.
The first includes extreme shade plants, those that must have moderate
to heavy shade to produce attractive plants and cannot be acclimatized
to high light. Examples of these plants include Aglaonema, Maranta and
Spathiphyllum. The second category includes extreme light plants, those
that must have high light to grow and cannot be acclimatized to low
light. For the most part, none of these plants are used in the foliage
industry, but would include plants such as pine trees or flowering
annuals that require full sun to bloom profusely. The last category
includes plants termed sun-shade, which means they can adapt or be
acclimatized to a wide range of light intensities. Examples of these
plants include Ficus, Dracaena, and Sansevieria, and it is within this
group we find t1e greatest application of the light acclimatization

Research has shown that foliage plants can be light acclimatized in
two ways: 1) plants can be grown under a specific shade level for their
entire production period, or 2) they can be grown under high light or
even full sun, and then converted to low light at some period during
production. Extreme shade plants must always be grown under shade,
while sun-shade plants can be grown with either system.

Nutrition Fertilization of foliage plants has a direct effect on
acclimatization which may be related to respiration rate or high soluble
salts. High levels of nitrogen and some other elements during
production have been shown to decrease ability of foliage plants to
adjust to interior environments. Increased respiration rates increase
carbohydrate consumption, often exceeding the amount produced through
photosynthesis, thus requiring use of stored reserves.

An understanding of the potting medium is necessary before
fertilizer programs can be developed. Of great importance is pH, since
it controls release of nutrients provided in the fertilizer program. If
pH is too low, it will reduce conversion of ammonia to nitrate nitrogen,
while high pH levels reduce availability of most microelements. Most
foliage plants grown best when the pH is between 5.5 and 6.5.

Relative levels of nitrogen, phosphorus and potassium in a
fertilizer analysis are referred to as the N-P205-K20 ratio. Research

in this area has shown that foliage plants grow very well on a 1:1:1
ratio, such as in an 8-8-8 or 20-20-20 fertilizer analysis, but just as
well on a 3:1:2 ratio, such as a 9-3-6 or 18-6-12 analysis. The
benefits of using the 3:1:2 ratio are reduced fertilizer costs per unit
of nitrogen and lower total soluble salts levels which improve a plant's
ability to acclimatize to interior environments. For these reasons, a
3:1:2 ratio fertilizer is suggested for foliage plant production.

Selection of the proper amount of fertilizer to apply to a specific
foliage crop varies with the growing environment. Some major factors
influencing fertilizer level include light intensity, temperature,
rainfall or irrigation level, and ability of potting medium to retain

Light levels or intensities used for production of foliage plants
must be selected for optimum plant growth as well as effect on
acclimatization. Best growth can be obtained at light intensities that
provide highly acclimatized plants. Table 1 provides information on
suggested fertilizers levels for a wide variety of foliage plants when
grown under recommended light intensities. If plants are grown under
higher light intensities, even full sun for plants like schefflera or
areca palms, the suggested fertilizer levels will have to be increased
by 50 to 100% (this is not recommended for production of acclimatized
plants). If lower light intensities are present, suggested fertilizer
level can be reduced by as much as 25%.

Temperature has a strong effect on fertilizer needs of foliage
plants. Most foliage plants grow slowly, if at all, when soil
temperatures drop below 60F and night air temperatures are 65"F or
below. Thus, maintenance of standard fertilizer levels during this time
is unnecessary and can often be reduced 50%. During high temperature
periods (85 to 950 days and 75" to 85" nights) foliage plants grow
rapidly and can utilize slightly more fertilizer than listed rates. A
general rule that will account for cool and warm season foliage
production is to reduce suggested fertilizer levels by 25% during
December February and raise them by 25% from June September.

Rainfall or irrigation level affects amount of fertilizer leached
from potting media. Where excessive levels of water are applied through
irrigation or where plants are grown under shadecloth and are open to
periods of heavy rainfall, irrigation levels can be adjusted downward to
reduce leaching. Addition of extra fertilizer is, however, desirable
after periods of excessive rainfall to compensate for leaching.

Nutrient retention ability (cation exchange capacity) of potting
media used to grow foliage plants is important in establishing
fertilizer levels. Fertilizer levels in Table 1 are based on
utilization of potting media composed primarily of organic components
with high cation exchange capacity. Examples of such potting media
include (1) 75% peat moss 25% sand, (2) 50% peat moss 25% pine bark
- 25% cypress shavings, and (3) 80% peat moss 20% perlite, styrofoam
or similar materials. Potting media composed of greater amounts of
sand, perlite, styrofoam or pine bark may require slightly higher
fertilizer levels.

Table 1. Suggested light and nutritional levels
potted acclimatized foliage plants.

for production of some

Fertilizer requirements
Light intensity lbs/1000 sq ft/yr
Botanical name (foot-candles) N P205 K20

Aeschynanthus pulcher
Aglaonema spp.
Aphelandra squarrosa
Araucaria heterophylla
Asparagus spp.
Brassaia spp.
Calathea spp.
Chamaedorea elegans
Chamaedorea erumpens
Chlorophytum comosum
Chrysalidocarpus lutescens
Cissus rhombifolia
Codiaeum variegatum
Coffea arabica
Cordyline terminalis
Dizygotheca elegantissima
Dieffenbachia spp.
Dracaena deremensis (cultivars)
Dracaena fragrans (cultivars)
Dracaena marginata
Dracaena other species
Epipremnum aureum
Ficus benjamin
Ficus elastica (cultivars)
Ficus lyrata
iTTttonia verschaffeltii
Gynura aurantiaca
Hedera helix
Hoya carnosa
Maranta spp.
Monstera deliciosa
Nephrolepis exaltata (cultivars)
Peperomia spp.
Philodendron scandens oxycardium
Philodendron selloum
Philodendron spp.
Pilea spp.
Pi ttosporum tobira
Polyscias spp.
Sansevieria spp.
Schlumbergera truncata
Spathiphyllum spp.
Syngonium podophyllum
Yucca elephantipes


Table 1 con't next page




1Rainfall or irrigation level affects amount of fertilizer leached from
potting media. Where excessive levels of water are applied through
irrigation or where plants are grown under shadecloth and are open to
periods of heavy rainfall, additional fertilizer may be necessary.
Significance to Industry
Increasing fertilizer costs and potential for environmental
pollution from leveling nutrients points out the need for the type of
information presented. These data are updated as new information is
obtained, to aid producers in efficient use of resources.
Additional Reading
Conover, C. A. and R. T. Poole. 1984. Light and Fertilizer
Recommendations for Production of Acclimatized Potted Foliage Plants.
University of Florida, IFAS, Agricultural Research Center Apopka
ARC-A Research Report RH-84-7.




Investigators: R. T. Poole and C. A. Conover

Although produces commonly utilize information obtained from
soluble salts readings to adjust fertility programs for foliage plants,
only limited information is actually available on soluble salts levels
that are adequate or excessive for good foliage plant growth.
Considerable research has been conducted on comparisons of different
methods of determining soluble salts levels (2), and these have been
useful. However, information is needed on specific tolerances of major
foliage plant genera. Also, data on soluble salts effects on plants
under interior environments is needed to aid in quality maintenance.

Genera included in this study included in this are Aglaonema,
Aphelandra, Chamaedorea, Codiaeum, Dieffenbachia, Dracaena, Epipremnum,
Nephrolepis, Philodendron and Spathiphyllum. Results have been obtained
by applying 10 fertilizer levels (2.4 to 24 g/6" pot/3 mo in 2.4 g
increments) using 19-6-12 Osmocote. Best quality plants have been
obtained when using 4.8 or 7.2 g/3 mo (1750 or 2600 lb N/A/yr). In many
cases higher rates did not improve or decrease quality even though
soluble salts readings ranged from moderate to very high (2000 6000
micromhos/cm in the leachate). Examples of results include tipburn and
necrotic spotting of Spathiphyllum foliage with fertilizer levels above
7.2 g/3 mo and a severe decrease in root system quality. With Dracaena
'Massangeana' incremental increases generally increased plant quality up
to 7.2 g (2600 lb N/A/yr) but plants receiving higher levels were
commercially acceptable. However, plant genality deteriorated after 3
months indoors, with chlorosis and necrosis/mottling occurring on plants
receiving more than 12.0 g, 4300 lb N/A/yr.

Significance to Industry
Upon completion of this research we will publish plant quality
curves related to fertilizer rate and soluble salts levels. This
information will then allow growers to determine whether their
production system is acceptable. Hopefully, this date will also aid
growers to reduce fertilizer costs and nutrient leaching.
Overfertilization not only reduces plant quality for consumers and
creates a bad impression for foliage plants, but it also increases
production costs and pollutes the environment.

Additional Reading
1. Joiner, J. N., C. A. Conover and R. T. Poole. 1981. Nutrition and
fertilization (Soluble Salts pp 256-263). In Foliage Plant
Production, J. N. Joiner Ed., Prentice Hall, Englewood Cliffs, N.J.

2. Waters, W. E., J. NeSmith, C. M. Geraldson and S. S. Woltz. 1972.
Interpretation of soluble salt tests and soil analyses by different
procedures. Univ. of Fla Agric. Res & Ed. Center Bradenton Mimeo
Report G.C. 1972 4. 9 pp.



Investigator: L. S. Osborne

Bemisia tabaci is a major pest of many agronomic crops throughout the
world. Of particular importance to Florida ornamental growers is the fact
that this insect has been reported to feed on over 500 different host
plants. In California this insect was present, but caused little economic
damage until it became, for some unexplained reason, a key pest on such
crops as lettuce, cotton, and tomato. A similar situation has developed in
Florida. Although Bemisia tabaci was first reported in Florida during the
late 1800's, it has been of little economic importance until recently.
During the past two years, growers of ornamental plants in greenhouses and
outdoors and from most areas of the state have reported major losses as a
result of this whitefly. Chemical control has achieved little success with
all but two of the many registered materials being reported ineffective.
Only abamectin and aldicarb have given growers any control of this whitefly
and these chemicals have not facilitated production of pest free plants.
This could present major problems for Florida agriculture in general and
specifically for ornamental growers. If it is demonstrated that this
strain is being spread to other regions of the United States by moving
infested ornamental plants, we may be faced with another regulatory problem
such as fire ants.

At the time this was written the only plants grown in this area that
have proven to be hosts for this whitefly are:

Aphelandra squarrosa
Brassaia actinophylla
Browallia (Bluebells)
Chansonette gazania
Chamaeranthemum spp.
Cineraria maritima 'Silver Dust'
Coleus 'Red Wizard'
Crossandra infundibuliformis
Dahlberg Daisy
Dahlia 'Figaro'
Euphorbia lactea
Euphorbia pulcherrima
Evolvulus glomeratus 'Blue Daize'
Ficus spp.

Gerbera jamesonii
Gomphrena 'Buddy'
Gynura aurantiaca
Hibiscus rosa-sinensis
Pansy 'Universal True Blue'
Petunia hybrida 'Telstar'
Petunia 'Ball All-Double'
Radermachera sinica
Red Hot Sally (Salvia)
Syngonium podophyllum
Tagetes (Marigold)
Vegetables (including Tomato,
Squash, Lettuce, Cucumber)

Because this insect has been found to infest a number of important
plants, the following research objectives have been identified as important
and research has begun.

OBJECTIVE A: Determine host range of B. tabaci among the major ornamental
plant species grown as foliage plants.
OBJECTIVE B: The life history of this pest will be studied.
OBJECTIVE C: Evaluate various control strategies.

In addition, we will evaluate different methods of applying pesticides
that have shown, in other studies, to increase efficacy. Any materials
that are effective will also be evaluated for phytotoxicity using our
standard methods. If no materials are identified that will allow us to
grow pest free plants, we will evaluate various biological control agents.
Significance to Industry
The specific problem this whitefly poses to Florida agriculture
remains to be determined, but it was responsible for losses of 100 million
dollars for California and Arizona growers and consumers in 1981. Cotton
yields were affected and quality was reduced by the presence of honeydew on
the bolls. Various cucurbits were damaged so severely that a disaster loan
was approved by the Farmers Home Administration. Lettuce plantings were
100% affected by a virus transmitted by this whitefly. Research on Florida
ornamentals is needed to determine control methods for this serious pest.
Additional Reading
Ball, V. 1987. Viewpoint, Grower Talks Vol. 50(11):12-14.
Gerling, D., A. R. Horowitz, and J. Baumgaertner. 1986. Autecology of
Bemisia tabaci: a review. Agriculture Ecosystems & Environment 17:5:19.
Meyerdirk, D. E. and D. L. Coudriet. 1986. Population dynamics and
control strategy for Bemisia tabaci in the Imperial Valley, California.
Agriculture Ecosystems & Environment 17:61-67.
Ohnesorge, B. and G. Rapp. 1986. Monitoring Bemisia tabaci: a review,
Agriculture Ecosystems & Environment 17:21-27.
Prabhaker, N., D. L. Coudriet, D. E. Meyerdirk. 1985. Insecticide
resistance in the sweetpotato whitefly Bemisia tabaci (Homoptera:
Aleyrodidae). J. Econ. Entomol. 78:748-752.
Sharaf, N. 1986. Chemical control of Bemisia tabaci. Agriculture
Ecosystems & Environment 17:111-127.



Investigator: L. S. Osborne

Research at the University of Florida, Central Florida Research and
Education Center in Apopka strives to solve the unique pest control
problems that growers of tropical ornamental foliage plants must contend
with. Plant-feeding mites are some of the most common and destructive
arthropods found infesting foliage plants in Florida greenhouses, homes
and interior landscape plantings. Extensive research on two biological
control agents for two-spotted spider mite (TSM) has been conducted on
ornamentals. These predators are Phytoseiulus persimilis (PP) and P.
macropilis (PM). Because of constraints placed on producers of
ornamental plants to produce a final product that is free of insects and
mites, the first commercial field trials in the southern United States
with predatory mites will probably occur in stock plantings where some
damage can be tolerated. Chronic mite problems occur in these areas and
are often spread to other areas of the greenhouse when cuttings are
taken for propagation. In spite of positive results from current and
past research, classical biological control of TSM has not been
implemented on ornamental crops in more than a few greenhouses
throughout Florida. The reasons are, in most cases, the same as those
hindering development of biological control in greenhouses world-wide.
The most important factor for ornamentals is the perception that we are
currently marketing pest-free products and that the use of biological
controls will result in products that are infested, damaged and of
inferior quality. However, complete reliance on chemical controls does
not insure quality plants because their use often results in unsightly
residues and phytotoxicity. Secondly, chemical controls are not always

A major limiting factor in the development of biological control of
TSM is the quantity and quality of predatory mites available in this
region of the United States: predators must be obtained by mail. There
are a number of problems associated with this practice:
1) Predators arrive in poor condition;
2) Predators are not available when needed;
3) Guidance and support groups are limited in the region;
4) Strains are not adapted for regional needs (climate,
5) There are governmental restrictions that require growers to
have permits to import biological control agents, even though they
already occur in the region.

Because biological control programs of arthropod pests infesting
ornamental foliage plants in Florida are only in the developmental
stages, there are no data to present on the number of growers utilizing
or even attempting to utilize biological controls in greenhouses. A

short discussion of projects currently in progress at the CFREC-Apopka

Non-disruptive Chemical Controls The acaricides used in the ornamental
industry often disrupt the predator-prey interaction to the extent that
acaricides are needed for the remainder of the growing season. Safer
Agro-Chem's Insecticidal Soap (IS) can be utilized to reduce mite
populations without significantly disrupting the interaction between the
predatory mite and its prey. Similar studies will be conducted with the
acaricides abamectin, clofentezine, and hexythiazox.

Modified Banker-Plant Method A new project has been initiated to
evaluate release methods for PP. One method we are investigating is a
modification of the "Banker-Plant" method for Encarsia formosa. In this
system, we envision using a host plant that is of little economic
importance in the foliage industry on which we can feed a host specific
phytophagous mite. These infested plants would then be inoculated with
PP and placed in the greenhouse to serve as a foci from which the
predators will disperse.

Microbial Pest Control Another area of ongoing research involves the
use of microbial agents to control various plant pests. However, major
problems exist that could impede the development of microbial control
programs. For example, our environment is so conducive to the
development of plant pathogenic organisms that many growers must apply
fungicides on a weekly basis. One of the most disruptive fungicides
used on a regular basis in this industry in benomyl. Therefore, we are
currently evaluating a benomyl-resistant (tolerant) strain of
Verticillium lecanii for the control of aphids.

Other pathogens being evaluated are Bacillus thuringiensis var.
israelensis, Beauveria bassiana, Hirsutella thompsonii, Neozygites sp.,
and Paecilomyces fumosoroseus.

Biological Control of Citrus Mealybug Finally, Leptomastix dactylopii
and Leptomastidea abnormis are being evaluated for the control of the
citrus mealybug, Planococcus citri. This mealybug is the most difficult
insect pest of foliage plants to control. Few chemicals are effective
for their control and those that are cause phytotoxicity or will be
disruptive to biological control programs for mites.

Significance to Industry
Development of these data will allow optimal use of biological
control agents for insects and mites on Florida ornamentals. A truly
integrated approach to pest control must involve potential "biological"
pesticides. This research is vital to implementation of the most modern
and scientifically sound methods for insect and mite control.

Additional Reading
Osborne, L. S., L. E. Ehler, and J. R. Nechols. 1985. Biological
control of the twospotted spider mite in greenhouses. University of
Florida AGr. Exp. Sta. Tech. Bull. 853:1-40.

Osborne, L. S. and F. L. Petitt. 1984. Insecticidal soap and the
predatory mite Phytoseiulus persimilis (Acari: Phytoseiidae), used in
management of twospotted spider mite (Acari: Tetranychidae) on
greenhouse grown foliage plants. J. Econ. Entomol. 78:687-691.
Osborne, L. S. 1986. Dip treatment of tropical ornamental foliage
cuttings in fluvalinate to prevent spread of insect and mite
infestations. J. Econ. Entomol. 79:465-470.
Petitt, F. L. and L. S. Osborne. 1984. Selected bibliography of the
predacious mite, Phytoseiulus persimilis. Athias-Henriot, (Acarina:
Phytoseiidae). bibliography Series Entomol. Soc. Am. 3, 1-11.


Investigator: L. S. Osborne

Production of tropical ornamental foliage plants is accomplished in
stages. The first stage is to obtain plant propagules such as seeds,
tissue cultured plantlets, and cuttings taken from established stock
plants. In order to grow quality plants in a minimum number of days,
the propagules must be as healthy and as free of pests as practicable.
In general, seeds and plantlets are seldom infested by mites or insects
at the time of planting. In contrast, stem and leaf cuttings, most
commonly used to propagate foliage plants can be infested with such
common pests as spider mites, mealybugs, aphids and whiteflies.

When cuttings are taken from infested stock plants, movement of
pests within the nursery and between nurseries can occur. Florida
foliage growers obtain substantial numbers of unrooted or bare root
cuttings from growers in Costa Rica, Puerto Rico, and other Caribbean
and Central American countries which frequently result in importation of
exotic pests. One case in point is that of Diaprepes abbreviatus which
was imported into Florida on cuttings of Dracaena marginata and has
resulted in many quarantine efforts.

Controlling pests on unrooted cuttings is very difficult and must
occur at a stage in plant production when conventional methods for
pesticide application cannot be used reliably. Systemic pesticides are
relatively ineffective since cuttings lack roots. High volume sprays
cannot be used since pesticides are washed from foliage when cuttings
are under mist (used to stimulate rooting) and because the sprays must
be applied with sufficient pressure to ensure adequate coverage thus
causing severe damage by blowing cuttings out of pots. Movement of
mites and insects on propagative material represents a severe problem
for growers of tropical ornamental foliage plants. Studies were
conducted to evaluate efficacy and phytotoxicity of several dip
treatments for unrooted cuttings infested with various arthropod pests.
Mavrik (fluvalinate) was evaluated in these studies because it is
effective in the control of a wide range of insect and mite pests and is
relatively safe to plants and mammals.

Cuttings of tropical ornamental foliage plants were dipped into
Mavrik at rates of 84, 168 (labeled rate), and 336 g AI/100 liters of
water for the control of Tetranychus urticae, Phenacoccus solani, Myzus
persicae, and Trialeurodes vaporariorum. When cuttings were dipped for
1 minute in the 168g rate of Mavrik, populations of all pest species
were reduced by at least 70%. Phytotoxicity studies were also conducted
with the following plant species: Dieffenbachia maculata; Dracaena
marginata; Codiaeum variegatum; Cissus rhombifolia; Cordyline
terminalis; Epipremnum aureum; Ficus pumila; Hedera helix; Hoya carnosa;
Maranta leuconeura kerchoviana; Peperomia obtusifolia; and Philodendron
scandens oxycardium. No noticeable foliar damage was observed for any

of the species tested. Significant reductions in the number of roots or
root weight were obtained for Cissus rhombifolia and Cordyline
terminalis when dipped in Mavrk at the 336g rate for 2 minutes. All
other species had normal or increased root development as a result of
dipping. Concentration of Mavrik in the dip solution had more effect on
the expression of phytotoxicity in C. terminalis than did the amount of
time cuttings were in the dip solutTon.
Significance to Industry
The significance of this research is that it gives the grower a
means by which to disinfest cuttings of tropical ornamental foliage
plants before the pests have the opportunity to infest other parts of
the greenhouse.


Investigators: L. S. Osborne and A. R. Chase

Chlorpyrifos has been used in Florida to prevent infestation of
potting media for ornamental plants with Diaprepes abbreviatus (sugarcane
rootstalk borer weevil) and Solenopsis invicta (red imported fire ant).
Only granular formulations of chlorpyrifos and heptachlor were legally
available for use to satisfy quarantine restrictions for these pests during
the first half of 1981. At this time, growers began to note that certain
plants died when planted in potting media treated with chlorpyrifos. Root
tissue from affected plants was collected and Pythium spp. were isolated
from some root systems. Phytotoxicity studies with chlorpyrifos, conducted
in sterile potting medium, indicated that the insecticide caused
significant reduction in growth of a number of greenhouse grown ornamental
plants including Begonia x rex-cultorum (Rex begonia).

Chlorpyrifos has been shown to have fungicidal activity in vitro
against a number of pathogens including species of Pythium, Fusarium,
Rhizoctonia, and Curvularia from turf. This insecticide also has been
shown to suppress white mold disease of peanuts caused by Sclerotium
rolfsii. Other soil pesticides have been found to increase severity of
sugar beet root rot caused by Rhizoctonia solani and cucumber root rots
caused Rhizoctonia spp., Fusarium oxysporum, and Pythium spp. The studies
reported here were initiated to evaluate effects of chlorpyrifos and
Pythium root rot, alone and in combination, on growth and survival of Rex

Incorporating granular chlorpyrifos (7.42g a.i./m3) or drenching with
an equivalent amount of a wettable powder formulation significantly reduced
growth of Rex begonia. Nontreated plants, inoculated with Pythium
splendens, were smaller in size than control plants. When plants were
treated with chlorpyrifos and inoculated with P. splendens, an interaction
between these two factors resulted in a synergTstic reduction in plant
growth. Degree of the interaction was influenced by formulation and rate
of chlorpyrifos used. Stunting caused by this interaction was reduced when
plants were treated with metalaxyl which is effective in controlling
Pythium root rot.

Significance to Industry
These results implicate soil applied insecticides in the incidence or
increased expression of some plant pathogens. Growers must be aware of
potential interactions between pests and pesticides.

Additional Reading
Backman,P.A., and Hammond, J.M. 1981. Suppression of peanut stem rot with
the insecticide chlorpyrifos. Peanut Science 8:129-130.
Cisons, A.S. 1985. Nontarget activity of chlorpyrifos and hydrolysis
products on Sclerotium rolfsii. Plant Dis. 69:254-256.
Hammond, J.M., Backman, P.A., and Bass, M.H. 1979. Nontarget effects of

the insecticide chlorpyrifos to certain soil-borne peanut pathogens.
Proc. J. Amer. Peanut Res. Educ. Assoc. 11:44.
Ruppel, E.G., and Hecker, R.J. 1982. Increased severity of Rhizoctonia
root rot in sugar beet treated with systemic insecticides. Crop
Protection 1(1):75-81.
Smiley, R.W. 1981. Nontarget effects of pesticides on turfgrass. Plant
Dis. 65(1):17-23.
Sprenkel, R.J., and Hale, D.B. 1985. Lorsban insecticide for the
suppression of white mold disease in peanuts. Down to Earth 40(2):1-7.
Sumner, D.R. 1978. Interaction of herbicides and ethoprop with root
diseases of cucumber. Plant Dis. Reptr. 62:1093-1097.


Investigator: A. R. Chase
One of the most serious diseases plaguing the foliage industry has
been Cylindrocladium root and petiole rot of Spathiphyllum. Chemical
and cultural control methods have been investigated extensively during
the past six years.
Chemical Control Chemical control has been researched with the result
that the only registered fungicide which provides significant disease
control is Benlate 50WP. More recently, two fungicides, prochloraz and
triflumizole, have been shown they have greater efficacy than Benlate
and a Section 18 has been proposed to EPA for triflumizole. The rates
and intervals of use for both of these fungicides have been determined.

Cultural Control The effects of potting medium components,
temperature, and pH, as well as watering frequency have shown that lower
potting medium temperatures (below 80 F), and higher potting medium pH
(6.5) are the most important for reducing severity of Cylindrocladium
root and petiole rot.

Breeding for Resistance Preliminary testing of commercial cultivars
and species has shown that only Spathiphyllum floribundum and its
relatives are significantly resistant (not immune) to C. spathiphylli.
Hybrids of this plant and others have resulted in transfer of the
resistance although plant quality has not been sufficiently high. It is
important to note that no Spathiphyllum species or cultivars have been
found which are immune to this disease.
Significance to Industry
Each of the above investigations has led to a more complete
understanding of this severe disease. Chemical control work has
directly influenced recommendations made to growers as well as chemical
company interest in registrations for this disease. The most viable
methods for influencing severity of this disease have been assembled in
a University of Florida Research Bulletin which should be available in
the next year.
Additional Reading
Chase, A. R. 1986. Cylindrocladium root and petiole rot control -
Update 1985. Proc. Fla. State Hort. Soc. 98:115-118.

Chase, A. R. and R. T. Poole. 1986. Role of potting medium pH and
temperature in severity of Cylindrocladium root and petiole rot of
Spathiphyllum. Plant Disease (In Press).

Henny, R. J. and A. R. Chase. 1986. Relative susceptibility of
Spathiphyllum spp. and cultivars used in breeding resistance to
Cylindrocladium spathiphylii. HortScience 21(3):515-516.


Investigator: A. R. Chase

Bacterial diseases are becoming more important and commonplace each
day. Although some of the most serious diseases such as those caused by
Erwinia spp. have been described, many of the newer pathogens and their
hosts are not adequately researched. During the past three years, an
ongoing project for description of new bacterial diseases has been

The following descriptions of bacterial diseases have been
completed since 1984.
Pseudomonas cichorii on Ficus lyrata
Pseudomonas cichorii on Schefflera arboricola and its relatives
Pseudomonas gladioli on Asplenium nidus and other ferns
Pseudomonas cichorii on Hibiscus rosa-sinensis
Pseudomonas syringae on Hibiscus rosa-sinensis
Xanthomonas campestris pv. hederae on Brassaia actinophylla, Schefflera
arboricola, and their relatives
Xanthomonas campestris pv. malvacearum on Hibiscus rosa-sinensis
Xanthomonas campestris pv. poinsettiicola on Codiaeum variegatum
Xanthomonas campestris pv. on Pilea and Pellionia spp.
Xanthomonas campestris pv. on StreTitzia reginae
Xanthomonas campestris pv. on Syngonium podophyllum

Significance to Industry
Accurate descriptions of diseases are one of the most important
steps in diagnosis and therefore disease control. Recognition of many
of the listed diseases as bacterial in nature has been dependent upon
the descriptions since symptomalogies were often unusual and mistakenly
identified as phytotoxicity. In addition, the ability to work with this
variety of bacterial diseases has led to many tests evaluating chemical
control of these diseases, allowing our research to stay as current as

Additional Reading
Chase, A. R., J. W. Miller and J. B. Jones. 1984. A leaf spot and
blight of Asplenium nidus caused by Pseudomonas gladioli. Plant
Disease 68:344-347.
Chase, A. R. 1984. Xanthomonas campestris pv. hederae causes a leaf
spot of five species of Araliaceae. Plant Pathology 33:439-440.
Chase, A. R. and D. D. Brunk. 1984. Bacterial blight of Schefflera
arboricola and some related plants caused by Pseudomonas cichorii.
Plant Disease 68:73-74.
Chase, A. R. 1987. Leaf spot and blight of Ficus lyrata caused by
Pseudomonas cichorii. Plant Pathology (In Press).
Miller, J. W. and A. R. Chase. 1986. A Xanthomonas disease of
Pellionia and Pilea spp. Plant Disease 70:346-348.


Investigator: A. R. Chase
Use of certain growth regulators is a common practice for several
ornamental crops in Florida. Sometimes the products are applied to
improve plant appearance by shortening internodes, and other times
plants are stimulated to flower. Cycocel (chlormequat chloride) is
applied to many of the potted Hibiscus rosa-sinensis to improve plant
shape and initiate flowering. The effect of this treatment on three
bacterial diseases was tested.
Cycocel (1 oz/gallon) was applied three times on weekly intervals
to ten cultivars of hibiscus. One month later, the plants were
inoculated with one of the following bacterial pathogens: Pseudomonas
cichorii, Pseudomonas syringae, and Xanthomonas campestris pv.
malvacearum. Disease severity was evaluated about 2 weeks after
inoculation. Cycocel consistently reduced disease severity, on all ten
cultivars, for all three bacterial diseases. Severity was reduced from
20 to 80% depending upon the cultivar, time of year, and pathogen
involved. Similar tests with Brassaia actinophylla showed that a single
application (1/4 oz/gallon), made 2 months prior to inoculation, reduced
severity of Alternaria leaf spot as well. In this case, plant
appearance was not appreciably affected by the Cycocel treatment.
Significance to Industry
Knowledge of the effect that growth regulators may have on plant
diseases is an important consideration in designing a pest management
program for any crop. The fact that three bacterial diseases of
hibiscus can be partially controlled with a treatment designed for
another purpose, may allow reduced applications of bactericides on these
Additional Reading
Chase, A. R., L. S. Osborne, J. M. F. Yuen, and B. C. Raju. 1987.
Effects of growth regulator chlormequat chloride on severity of three
bacterial diseases on ten cultivars of Hibiscus rosa-sinensis. Plant
Disease 71:186-187.



Investigator: A. R. Chase

The role of host fertilization in susceptibility to bacterial
diseases has been investigated over the past three years. Since
chemical control of bacterial diseases is frequently unsatisfactory due
to poor efficacy or phytotoxicity, use of alternative methods to reduce
disease severity is especially important for bacterial diseases.

Erwinia blight Initial studies on the effect of fertilizer rate on
severity of Erwinia leaf spot of Syngonium has shown that this disease
is not affected by fertilizer rates between x (recommended) and 8 x.

Pseudomonas leaf spot The following plants have been included in
trials with fertilizer rate and Pseudomonas cichorii: Chrysanthemum
morifolium, Ficus lyrata, and Schefflera arboricola. Increasing
fertilizer rates increased severity of Pseudomonas leaf spot on
chrysanthemum, but decreased severity on the dwarf schefflera and fiddle
leaf fig.

Xanthomonas leaf spot Several pathovars of Xanthomonas campestris were
tested on foliage plants for effects of fertilizer on disease severity.
Xanthomonas campestris pv. hederae was less severe on Schefflera
arboricola and Brassaia actinophylla as fertilizer rate was increased.
Xanthomonas campestris pv. dieffenbachiae causing Syngonium blight was
also reduced as fertilizer level increased. The rates of nitrogen and
potassium were both found to affect disease severity alone or in
combination. Xanthomonas campestris pv. poinsettiicola on Codiaeum
variegatum and a pathovar of X. campestris from Pilea spruceana were not
affected by fertilizer level.

Significance to Industry
Use of this information will allow growers to produce foliage
plants which are more resistant to these bacterial diseases. Further
research will be conducted regarding the use of bactericides and
fertilizer rate for control of selected diseases.

Additional Reading
Chase, A. R. and J. B Jones. 1986. Effects of host nutrition, leaf
age, and preinoculation light levels on severity of Pseudomonas leaf
spot of Schefflera arboricola caused by Pseudomonas cichorii. Plant
Disease 70:561-563.

Jones, J. B., A. R. Chase, B. K. Harbaugh and B. C. Raju. 1985. The
effect of leaf moisture period, fertilizer rate, leaf age and light
intensity as preinoculation factors on susceptibility of chrysanthemum
to bacterial leaf spot. Plant Disease 69:782-784.
Chase, A. R. and R. T. Poole. 1987. Effects of fertilizer rates on
severity of Xanthomonas leaf spot of schefflera and dwarf schefflera.
Plant Disease (In Press).



Investigator: A. R. Chase

Both air and potting medium temperature can affect development of
some diseases. Rhizoctonia solani is a soil-borne plant pathogen which
causes a foliar disease of many foliage plants such as Boston fern. The
effect of temperature variation in both the leaf and root zones was
evaluated for this plant and disease.

Boston ferns were obtained from commercial producers and
established in temperature controlled growth chambers. Root
temperatures were either 80 or 90 F and maximum air temperatures were 95
or 105 F. The percentage of the plant foliage with symptoms of aerial
blight was rated about ten days after inoculation with R. solani.
Disease severity was consistently lower for plants with a potting medium
temperature of 90 and an air temperature of 105 F. The worst disease
developed on plants with an 80 F potting medium temperature and a 95 F
air temperature. This indicates that although aerial blight has always
been thought of as a hot weather disease, weather which results in
potting medium temperatures of 90 F or air temperatures of 105 F
actually reduce severity of this disease on Boston fern.

Significance to Industry
Maintaining greenhouse temperatures at the highest level which
allows good plant growth can reduce severity of Rhizoctonia aerial
blight on Boston fern during the hottest times of the summer as well as
reducing cooling costs.

Additional Reading
Chase, A. R., and C. A. Conover. 1987. Temperature and potting medium
effects on growth of Boston fern infected with Rhizoctonia solani.
HortScience 22(1):65-67.


Investigator: R. H. Henny
Several years of breeding research has led to the development of a
large number of new Aglaonema, Dieffenbachia and Anthurium hybrids.
Selected hybrids have been propagated and are now being evaluated in
production tests. These studies evaluate effects of light and nutritional
levels on hybrid performance in the greenhouse and indoors.

Significance to Industry
Results of these tests (3 tests per hybrid) are used to formulate
production guidelines for producers which are published with release of
each hybrid.
Additional Reading
Henny, R. J. 1982. Fertility, sterility, and crossability within the genus
Dieffenbachia. ARC-A Research Report RH-82-22.
Henny, R. J. and E. M. Rasmussen. 1982. Aglaonema hybridization guide.
ARC-A Research Report RH-82-16.
Henny, R. J. 1985. Foliage plant breeding profile I. Dieffenbachia
maculata 'Perfection'. AREC-A Research Report RH-85-15.
Henny, R. J. 1985. Foliage plant breeding profile II. Dieffenbachia
maculata 'Camille'. AREC-A Research Report RH-85-22.
Henny, R. J. 1985. Foliage plant breeding profile III. Aglaonema nitidum
'Curtisii'. AREC-A Research Report RH-85-23.
Henny, R. J. and W. C. Fooshee. 1985. Cleaning Aglaonema seeds promotes
germination and growth of seedlings. AREC-A Research Report RH-85-18.
Henny, R. J. and W. C. Fooshee. 1985. Inducing flowering of four
Spathiphyllum cultivars with gibberellic acid (GA3). AREC-A Research
Report, RH-85-3.
Henny, R. J. and W. C. Fooshee. 1985. Increasing basal shoot number in
Spathiphyllum 'Tasson' with BA. AREC-A Research Report, RH-85-24.
Fooshee, W. C. and R. J. Henny. 0985. Guidelines for preparing solutions
of gibberellic acid (GA3) and N -Benzyladenine (BA). AREC-A Research
Report RH-85-13.
Henny, R. J., C. A. Conover, and R. T. Poole. 1986. Triumph A hybrid
Dieffenbachia for foliage producers. Agric. Exp. Stn. Circ. S-334. 6 pp.



Investigators: R. T. Poole and C. A. Conover

For several years receivers of Dracaena fragrans Ker. 'Massangeana'
shipments have complained of severe deterioration of 'Massangeana'
quality soon after receipt of the plants. Since March of 1985, 25
experiments, most of them 2 factor factorial, have been completed at the
Central Florida Research Center Apopka.

Levels range from 1500 to 7000 pounds of nitrogen per acre per year
(PPA/yr-N). There was no difference between treatments in four of the
experiments. In a fifth experiment 2500 and 3500 PPA/yr-N produced
slightly better plants that 1500. When 5, 10 or 15 g of Peters 20-20-20
was added to an 8" pot in the morning and plants were stored in the
afternoon for 4 days, plants showed necrosis within a week after
fertilizer application.

Irrigation During Production Plants were irrigated 1, 3 or 5 times
weekly from April through October. Even though pots watered once were
dry before the next watering, and pots watered 5 times were constantly
wet, all plants were of good quality with plants in pots watered 3 times
weekly slightly better after 4 days storage.

Moisture of Pots Before Shipping Treatments varied between pots that
were completely soaked prior to placement in storage to pots that were
last watered 10 days before storage. All plants were of high quality.

Production Temperature Two experiments were conducted in the
greenhouse from May and June to October in sections where temperatures
were allowed to reach maximums of 90, 95, 100 or 105*F before fan and
pads operated. All plants were good quality after storage.

Loading and Shipping Temperature Before or after plants were placed in
storage they were subjected to temperatures of 50-110*F for 6 hours.
When plants were subjected to loading temperatures of 70, 90 or 110F
before or after storage temperatures of 55, 65 or 75F, plants were of
approximately equally good quality. But plants going from extremes,
e.g. 55"F storage temperature to 110*F loading temperature, had the
poorest plant grade. Quality of plants kept at high temperatures, e.g.
90F loading temperature and moved to 85F storage temperature was much
poorer than plants kept at 50F loading temperature and moved to 65F
storage temperature.

Storage (Shipping) Temperature Eleven experiments were conducted, 7
with temperatures of 55, 65 or 75F. Four tests were non-significant,
the others indicated 55 and 65"F were slightly better than 75"F.
Temperatures in the 4 other tests ranged from 35 85F. Temperatures

of 35 and 45"F produced cold damaged leaves, and 85F also produced some
leaf chlorosis.
Ethylene Quality of plants exposed to 100 ppm ethylene for 72 hours
were equal in quality to control plants. The resistance of
'Massangeana' to ethylene exposure is in sharp contrast to Ficus
benjamin which drops its leaves at 1 ppm.
Fluoride Fluoride has been proven harmful to 'Massangeana' but 3
tests, 2 with NaF and 1 with single superphosphate with maximums of 1000
mg of F/8" pot or 6 Ibs/yd single superphosphate did not reduce quality
when 7 Ibs/yd of dolomite was added.

Root Pruning One quarter or one half of the roots of well-rooted cane
were removed. All plants were of equal quality 2 weeks after removal
from storage.

Packaging Plants were sleeved with sleeves left open, sleeved with
tops stapled, and open sleeved and boxed at temperatures from 45 to 85F
with no advantage to any kind of packaging.
Significance to Industry
'Massangeana' can tolerate and thrive at high fertilization levels.
Irrigation during production will influence quality but is not a factor
in poor quality after storage. Moisture content of pots can vary
considerably without influencing quality. Plants can tolerate high
temperature levels during production. Temperature before or after
shipping might influence chlorosis. Extreme differences in temperature
should be avoided when moving plants from the nursery into the truck or
container, and when moving the plants from truck or container to the
nursery or retailer. High temperatures and low temperatures should be
avoided. 'Massangeana' are apparently very tolerant to high ethylene
concentrations. Ethylene should not be a problem. If dolomite is added
to the soil medium and pH above 5.5, fluoride should not be a problem.
Root damage would have to be severe to influence plant quality.
Packaging does not appear to determine leaf chlorosis.



Investigators: C. A. Conover and R. T. Poole
Extensive research (3, 4) has shown that acclimatized foliage plants
grow and survive under interior environments that are often damaging to
nonacclimatized plants. Benefits of acclimatization have resulted in
interiorscapers specifying acclimatized foliage plants for most indoor
plantings. Consumers are also aware of the benefits of purchasing and
using acclimatized foliage plants in their living spaces, although they
often do not know how to select such plants.

Transportation of foliage plants over long distances has become common
in recent years (5, 8). However, parameters for shipping foliage plants
have been vague and quality has often decreased during transport. The
primary method of shipping potted foliage plants within the U.S. and Canada
has been by truck; generally in temperature controlled reefers, but also in
trucks without temperature control. Product quality has been satisfactory
after shipping for 3 to 7 days provided temperatures were maintained
between 60 and 700F.

The research discussed in this report was initiated in 1979 when
facilities necessary for conducting simulated shipping experiments were
acquired. Initially emphasis was placed on short shipping durations (2,
7), but this was changed to longer durations in 1981. In all our shipping
research we utilized acclimatized potted foliage plants which had been
grown under specified light and nutritional levels to maximize adaptability
to interior environments.

Factors, such as light, water, fertility, etc., that occur during the
growing period can have a large effect on the ability of a plant to
maintain high quality during shipping and when placed in an interior
environment. Therefore, proper production procedures and pre-shipping
handling can have a large effect on the ability to ship potted foliage
Preparation for Shipping

Watering Research has been conducted on the influence of soil
moisture level at time of shipping (1). Excess leafdrop has occurred when
the potting medium was either too dry or too wet. Previous recommendations
concerning irrigation the day before or the day of shipping do not appear
to be valid. Thus we feel that neither wet nor dry media are desirable,
and the media should be moist (about 50% of capacity) at time of shipping.

Fertilization Although we have not observed increased loss of plant
quality during shipping from high fertilization levels, we nevertheless

suggest that plants not be fertilized during the week before shipping.
This is especially true for granulated and encapsulated fertilizers, since
they tend to slip between the potting medium and the container wall during

Packaging material The packing method utilized depends on how the
plant material will be handled and the type of shipping container. We have
observed that plants shipped without sleeping or boxing in full container
loads maintain quality and high humidity levels. The same high humidity
levels can be obtained in partial loads when plants are boxed or sleeved
with the sleeve closed at the top (9). In all long-term shipments (more
than 1 week) the reefer air controller should be placed in the closed
position so as to maintain high humidity, or plants should be boxed.

Relative humidity Short term shipments (7 days or less) rarely
induce plant desiccation even if humidity within the container is low. As
long as relative humidity is maintained between 80 and 90%, there will be
little loss in quality even during long-term shipments provided
acclimatized plants are shipped and suggested shipping durations are not

Foliage moisture Presence of free moisture on the foliage at time
of packing (dew, irrigation water, rainfall) may present problems during
shipping if disease is present. The best policy is to pack and ship plants
with dry foliage. Since this cannot always be done, one must recognize the
problem and the possible results. Most diseases affecting foliage plants
will not develop rapidly at lower shipping temperatures (55 to 60"F), but
they may be severe at 75F. Therefore, adjustment of shipping temperatures
may be beneficial in reducing disease severity if plants with wet foliage
are shipped.


Temperature The actual air temperature surrounding a plant during
shipping has a direct influence on the plants physiological processes. Low
temperatures reduce respiration and aid in conserving stored carbohydrates,
but if too low, may cause chilling injury (6). On the other hand, high
temperatures will increase respiration and possibly ethylene evolution.
Therefore, the correct shipping temperature is the one that maintains
optimum plant quality for the period of shipping and thereafter. Suggested
shipping temperatures for a wide range of foliage plants are listed in
Table 1.

Duration The actual period of time a plant is shipped has a
tremendous effect on quality. Short term shipments (1 7 days) are
possible with most foliage plants, provided the temperature is maintained
between 60-65F. Long-term shipments (8 28 days) often require more
specific temperatures, since plants will be under stress longer. We have
observed that some plants ship better at lower temperatures, but over
longer terms chilling injury may occur. Shipping of foliage plants is not
a process that increases quality, and one should remember that the shortest
time period is the best.

Humidity Replicated research has not shown the most desirable
relative humidity for shipping, but observation has shown that desiccation
can occur at low relative humidity. Based on the experiences of shippers
and our own observations, we concluded that relative humidity of 80 90%
resulted in maintenance of highest plant quality. For long-term shipments
this has required shipping in sealed containers.

Ethylene Foliage plants are generally not ethylene producers, and
ethylene is rarely found within foliage plant shipping containers.
However, ethylene has been shown to cause damage to certain foliage plants
at levels of 1 to 2 ppm. Ethylene can be produced in fairly large amounts
by fruits and vegetables during ripening therefore, these items should
never be carried as mixed loads with foliage plants. Ethylene evolution is
greater at higher air temperatures, as is its activity. Therefore,
recommended shipping temperatures should be as low as can be achieved
without causing chilling injury.

Time of year Some data indicate that plants produced during certain
seasons have greater potential for maintaining quality during shipping than
others. Ficus benjamin plants shipped in late summer incur severe
chilling damage when shipped at 50"F, but not at 550F. During winter or
spring, however, these plants do not incur chilling damage at 50"F. In
general, foliage plants shipped during spring maintain quality better than
plants shipped at other times.

Significance to Industry
Data presented will aid producers in selecting shipping temperatures
and durations that will preserve highest plant quality.

Additional Reading

1. Ben-Jaacov, J., R. T. Poole and C. A. Conover. 1982. Effect of
Nutrition, Soil Water Content and Duration of Storage on Quality of
Dieffenbachia maculata (Lodd.) G. Don 'Rudolph Roehrs'. HortScience

2. Conover, C. A. 1980. Maintaining foliage plant quality during
transit. Florists' Rev. 165(4290):31,69.

3. Conover, C. A. and R. T. Poole. 1985. Acclimatization of Foliage
Plants, a manual. Hort. Res. Inst., Washington, D. C. 8 pp.

4. Conover, C. A. and R. T. Poole. 1984. Acclimatization of indoor
foliage plants. Hort. Rev. 6:119-154.

5. Conover, C. A. and R. T. Poole. 1983. Handling and overseas
transportation of acclimatized foliage plants in reefers. Univ. of
Fla., IFAS, Agric. Res. & Ed. Ctr. Apopka Research Report RH-1983-1.

6. Poole, R. T. and C. A. Conover. 1983. Factors influencing chilling
damage of foliage plants. Interscape 5(14):12-13.

7. Poole, R. T. and C. A. Conover. 1979. Influence of shade and
nutrition during production and dark storage simulated shipment on
subsequent quality and chlorophyll content of foliage plants.
HortScience 14:617-619.

8. Poole, R. T. and C. A. Conover. 1983. Influence of simulated shipping
environments on foliage plant quality. HortScience 18(2):191-193.

9. Poole, R. T. and C. A. Conover. 1983. Packaging of Foliage Plants for
Shipment. Nurserymen's Digest 17(11):86-87.

Table-1. Suggested shipping or storage temperatures (F) for acclimatized
foliage plants.

Plant name 1-14 days 15-28 days

Acoelorrhaphe wrightii 50-55 -
Aglaonema 'Fransher' 55-60 60-65
Aglaonema 'Maria' 55-65 55-65
Aglaonema 'Silver Queen' 60-65 60-65
Aphelandra squarrosa 55-60 55-60x
Araucaria heterophylla 50-65 50-65
Ardisia crispa 50-60 50-60
Aspidistra elatior 50-55 50-55
Asplenium nidus 50-65 50-65
Beaucarnea recurvata 55-60 55-60
Brassaia actinophylla 50-55 50-55
Cereus peruvianus 55-60 55-60
Chamaedorea elegans 50-60 50-60
Chamaedorea seifrizii 55-60 55-60
Chrysalidocarpus lutescens 55-65 60-65y
Codiaeum variegatum 'Norma' 60-65 60-65
Cordyline terminalis 'Baby Doll' 55-60 50-55y
Cordyline terminalis 'Dragon Tongue' 60-65 -
Crassula argentea 50-65 50-65
Dieffenbachia 'Tropic Snow' 55-65 55-65
Dizygotheca elegantissima 55-60 55-60
Dracaena deremensis 'Janet Craig' 60-65 -
Dracaena deremensis 'Warneckii' 60-65 -
Dracaena fragrans 'Massangeana' 60-65 60-65
Dracaena godseffiana 'Florida Beauty' 55-65 55-60x
Dracaena marginata 55-65 60-65y
Dracaena reflexa 50-65 50-65
Epipremnum aureum 55-60 55-60x
Ficus benjamin 55-60 55-60
Ficus elastica 'Burgundy' 50-60 50-55

Table 1. con't.

Plant name
Ficus elastica 'Robusta'
Ficus lyrata
Ficus nitida
Hedera helix 'Eva'
Hedera helix 'Sweetheart'
Howea forsterana
Hoya carnosa 'Tricolor'
Maranta leuconeura
Nephrolepis exaltata 'Bostoniensis'
Philodendron scandens oxycardium
Philodendron selloum
Phoenix roebelenii
Pilea 'Moon Valley'
Pilea 'Silver Tree'
Pittosporum tobira
Pittosporum tobira 'Wheelerii'
Plectranthus australis
Podocarpus gracilior
Rhapis excelsa
Schefflera arboricola
Spathiphyllum 'Mauna Loa'
Syngonium 'White Butterfly'
Washingtonia robusta
Yucca elephantipes

1-14 days

15-28 days

ZPlants shipped or stored for 1 to 7 days
temperature listed for that plant.

should be held at the highest

YPlants observed to have a loss in quality of about 25% per week beyond 2
xPlants observed to have severe loss in quality beyond 2 weeks.
WData not available.



Investigators: R. T. Poole and C. A. Conover

Plants in office buildings and malls are subjected to many
environmental stresses. Sometimes the soil medium is the nearest
receptacle for cleaning fluid, the liquid or powder might be spilled on
foliage or stems and vapors enclose the plant in a poisonous cloud. Two
floor cleaners and a glass cleaner were tested for their phytotoxic
effects on seven foliage plants.

The materials were poured individually on the soil at suggested
cleaning usage rates. The material was sprayed on different plants at
the same rates and placed in beakers in rooms containing an additional
group of plants. Fumes had marginal effect. One floor cleaner reduced
quality of F. benjamin. Fumes from all materials reduced quality of
Spathiphyllim 'Tasson'. Spray applied to plants from one cleaner
reduced quality of Dieffenbachia 'Anne', Schefflera arboricola, Neathe
Bella palm, Compacta fern and Spathiphyllum 'Tasson'. Drenching the
materials into the pots had the most significant effect. All materials
harmed the dieffenbachia, fern and spathiphyllum. Ficus, arboricola and
croton 'Norma' were not affected by soil drenching. Palms were damaged
severely by one floor cleaner and moderately by the glass cleaner.
Cleaning materials can damage foliage plants.

Significance to Industry
The reaction of foliage plants to the cleaners differs greatly. No
cleaner should contact these plants neither by soil, leaf contact or
fumes. If damage by cleaners is suspected, cleaners used in the area
should be obtained and tested on the plants.

Additional Reading
Poole, R. T. and C. A. Conover. 1986. Response of foliage plants to
commercial interior paints. AREC-Apopka Research Report RH-86-15.


Investigators: R. T. Poole and C. A. Conover

Some Ficus benjamin which were apparently grown and maintained
properly, experienced severe leaf drop and even death after placement
indoors. One possible cause could be mercury placed in paint as a

A large number of plants were exposed to commercial paints
containing mercury in enclosed rooms. Only Dieffenbachia and Ficus were
affected by mercury released from the paint surface as a vapor.
Dieffenbachia reacted slower than Ficus which began to experience heavy
leafdrop about a week after placement in the rooms.

Significance to Industry
The results of these experiments may explain some of the severe
problems experienced by interiorscapers with Ficus benjamin. Mercury
is used in some paints to control mildew, although it is not the only
mildewcide used by paint formulators. We have been told by paint
manufacturers selling national brands that most do not contain mercury.
The data presented indicate that interiorscapers should specify paint
without mercury in commercial buildings. When severe leafdrop on Ficus
benjamin occurs suddenly after installation or repainting, the paint-
formulation should be obtained to determine whether mercury is present.


Investigator: L. S. Osborne

The pharaoh ant, Monomorium pharaonis is cosmopolitan in its
distribution having been carried by commerce to inhabit all regions of
the earth. This ant, which normally does not nest outdoors except
occasionally in warmer climates, is a major indoor pest in many parts of
the world, including the United States. The ant infests almost all
areas of a building where food is available and also in areas where food
is normally not found such as, intensive care units in hospitals. In
fact, this pest has become a major problem in hospitals by penetrating
i.v. solutions, feeding on dressed wounds, contaminating sterile
equipment and even carrying pathogenic bacteria. The pest control
industry in the United States is experiencing increased problems in
controlling this ant and many companies are now putting clauses in their
customer contracts which exclude coverage of pharaoh ants. The reason
for this is the difficulty in maintaining control since pharaoh ant
infestations usually require numerous return visits which may or may not
satisfy the customer. Also, if the ant colonies are not eliminated
completely, reinfestations occur rapidly. Homeowners have been known to
consider selling their homes because of severe infestations of pharaoh

This insect has been found infesting potted plant material in
hospitals, malls, and retail florist shops. These infestations have
occurred in established Ficus trees as well as plants that were just
brought into the hospitals. At the present time we don't know what
impact this will have on the interior landscape industry but it could
prove severe.

Because this insect has been found to infest a number of plants and
potted plants have been implicated as a means by which structures become
infested, the following research objectives have been identified and
research has begun.

We will evaluate the ability of this insect to establish itself in
potted plants growing in the greenhouse or holding area for plants that
are soon to be placed in interiorscapes. The effect of various cultural
practices will be determined. Pesticides will be evaluated for their
ability to prevent this ant from becoming established within the potted
plant both in the greenhouse and interior landscape. Pesticides will
also be screened for phytotoxicity. These materials will include those
compounds commonly used by pest control companies as well as those
available to the technicians maintaining the plants in the

Significance to Industry
In Europe, where this insect is also a major pest, many hospitals
do not allow people to bring plant materials inside. If this were
implemented in the United States, this could reduce a portion of the
industries potential market. Secondly, if the general public were to
receive ornamental plants as a means by which their house or business
could become infested with this ant, the results could be serious.
Finally, even if this problem does not originate in the greenhouse,
pesticides will be applied to plants in the interior landscape by pest
control operators to control pharaoh ant infestations a practice which
could cause severe phytotoxicity and substantial plant losses.

Additional Reading
Beatson, S. H. 1972. Pharaoh ants as pathogen vectors in hospitals.
Lancet 1:425-7.
Edwards, J. P. 1975. The effects of a juvenile hormone analogue on
laboratory colonies of Pharaoh's ant Monomorium pharaonis Bull. Ent.
Res. 65:75-80.
Smith, M. R. 1965. House-infesting ants of the eastern United States:
Tech. Bull. 1326. 105 p.
Wheeler, W. M. 1910. Ants: their structure, development, and behavior.
Columbia Univ. Press. N.Y.
Wilson, G. R. and M. J. Booth. 1981. Pharaoh ant control with IGR in
hospitals. Pest Control 49:14-19, 74.