Central Florida Research 1
And Education Center
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Seg rsoity of Florida
Research and Extension
Florida's Environmental Horticulture Industry
Florida's Environmental Horticulture Industry
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Central Florida Research and
Education Center Apopka:
Programs for the Ornamentals Industry
Ann R. Chase
Charles A. Conover
Richard W. Henley
Richard J. Henny
Lance S. Osborne
Richard T. Poole
Robert H. Stamps
University of Florida
Institute of Food and Agricultural Sciences
Central Florida Research and Education Center Apopka
CFREC Apopka Research Report, RH-91-2
We are especially grateful to the many firms and individuals for providing
support in the form of gifts, grants, equipment, plants, supplies and research sites
for the programs at the Central Florida Research and Education in Apopka.
Further input from many individuals regarding potential research projects is also
appreciated since this is one of the best ways to direct our research toward the
needs of the industry. Our programs would not be possible without this level of
support. Finally, the faculty at the CFREC-Apopka also wish to thank our staff
for their dedication and interest in their jobs.
Sr. Biological Scientist
Sr. Biological Scientist
Sr. Biological Scientist
Central Florida Research and
Education Center Apopka:
Programs for the Ornamentals
A. R. Chase, C. A. Conover, R. W. Henley, R. J. Henny,
R. T. Poole, L. S. Osborne and R. H. Stamps
TABLE OF CONTENTS
Introduction and Area Map ..................
Station Map and Key to Facilities ..............
Plant Pathology Programs
A. R. Chase ..................
Production of Foliage Plants
C. A. Conover and R. T. Poole . . .
Foliage Plant Extension and Plant Evaluation Program
R. W Henley ...................
R. J. Henny .....................
L. S. Osborne ...................
Cut Foliage Research
R. H. Stamps ....................
IFAS IS .............
. . . . . . . . . . 17
Correspondence with research or extension faculty regarding completed
projects or extension publications should be addressed to: Central Florida
Research and Education Center Apopka, 2807 Binion Rd., Apopka, FL
32703. Telephone number (407) 884-2034.
Central Florida Research and
Education Center Apopka
The Central Florida Research and Education Center Apopka was established
primarily through the efforts of local nurserymen and agricultural leaders who
recognized the need for research on problems associated with commercial foliage
Orange County purchased 18 acres of land and
donated it to the University of Florida for the site.
Building funds for an office building, greenhouse, and
storage building were appropriated by the 1965 State
SLegislature. Operating funds were appropriated by a
special session of the Legislature in 1968 as part of the
special appropriation for the Institute of Food and
Agricultural Sciences. The center officially opened
September 1, 1968 with only the office building.
Research facilities at this center have been vastly expanded since 1968 and
have been designed to closely duplicate grower conditions with plants grown
under shade cloth, fiberglass and glass. Presently, there are over 40,000 square
feet of research area for plant production. The center also has over 3,000 square
feet of controlled environment rooms to test indoor growth of foliage plants under
The primary objective of this research center is to conduct research and assist
in State Extension activities on commercial ornamental horticultural crops of
Florida. The Central Florida Research Center is the only known center of its
kind in the United States whose primary objective is to conduct research on
commercial foliage, cut foliage, and fern crops. Center personnel are responsible
for a vast majority of information pertaining to the industry. Everything from
rates and blends of fertilizer application to disease and insect control is studied
under various test conditions set up within the center's shadehouses, greenhouses,
or indoor facilities, or occasionally at a grower's range.
Major research emphasis is placed on effects of biological and physical stress
on plant growth, with programs in plant physiology, plant pathology, genetics,
entomology, nematology, and horticulture. Also, to help increase consumer
satisfaction with Florida products, studies have been initiated on factors affecting
shipping and interior utilization of foliage plant and cut foliage products.
To service this rapidly expanding industry, the Center has grown from three
faculty and four career service personnel in 1968 to its presents seven faculty and
20 career service personnel. Research faculty now includes a horticulturist, plant
physiologist, entomologist, plant pathologist, fern horticulturist, plant geneticist,
and foliage extension specialist.
Foliage plants have been commercially grown in Florida since 1928, with
production skyrocketing in the past two decades. Foliage plant producers grossed
$15 million wholesale in 1970, which grew to nearly $250 million annually in
1980 and $350 million in 1988.
More than 300 kinds of tropical foliage plants are
presently produced in Florida a tremendous increase
from the industry's early years. The first, and almost
only, plant commercially grown in Florida from 1919 to
the early 1930s was the Boston fern (Nephrolepis exaltata
'Bostoniensis'). In 1957, Philodendron scandens
oxycardium heartleaff philodendron) accounted for 33
percent and all species of Sansevieria accounted for 16 percent of the total value
of foliage plants sold.
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C. F. R. E. C. Apopka Facilities
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Reception, Faculty Offices and Library
Head House, Physiology and Extension Labs
Breeding and Tissue Culture Labs
Shipping Coolers, Cut Foliage,
Physiology and Entomology Labs
Pesticide Storage and Mixing
Maintenance and Soil Mixing
1 mii Pathology
3 i Entomology
4 : Pathology and Physiology
5 Physiology and Cut Foliage
6 J Entomology
7 iiBreeding and Physiology
o*o* 2o oooo
Fernery (Mixed Crops)
Twin Shade Houses
Potted Cut Foliage
Restrooms Located in Building 1
Plant Pathology Programs
A. R. Chase
Diseases of ornamentals seriously limit production of many ornamental crops.
Plant pathogens which are especially important include a wide variety of fungi
and several genera of bacteria. Research during the past eleven years has
included many of these organisms.
Bacterial diseases are becoming more important and
commonplace each year. Although some of the most
serious diseases, such as those caused by Erwinia spp.
have been described, many other pathogens and their
hosts have not been adequately researched. During the
past eight years, an ongoing project for description of
Snew bacterial diseases has been underway. Accurate
descriptions of diseases are one of the most important
steps in diagnosis and therefore disease control.
Recognition of many of the bacterial diseases has been
dependent upon isolation and identification since
symptomatologies were often unusual and mistakenly
identified as phytotoxicity, insect damage or fertility imbalances. In addition, the
ability to work with a variety of bacterial diseases has led to many tests
evaluating chemical and cultural control of these diseases.
Controlling bacterial diseases with bactericides has not always been
satisfactory due to low efficacy and potential for phytotoxicity. Preliminary
research has indicated that Aliette 80WP (normally used for control of
Phytophthora or Pythium root rot) has some activity in controlling diseases caused
by Xanthomonas campestris pathovars. Use of fungicides for control of certain
bacterial diseases will increase the chances of labeling a product for bacterial
disease control since marketing a product as a bactericide alone has been too
expensive for the chemical companies to pursue on ornamentals. Most recently,
Agribrom has shown excellent promise in controlling a wide variety of bacterial
diseases encountered during mist propagation. These include Erwinia blight of
Philodendron sellown, Pseudomonas leaf spots of Impatiens and Bougainvillea
and Xanthomonas leaf spots of English ivy, syngonium, geranium, and ficus. In
addition, Agribrom has provided some control of certain fungal diseases such as
Rhizoctonia aerial blight of Boston fern and pothos and Alternaria leaf spot of
Many fungal diseases have been described
during the past nine years. These diseases have
been the focus of many fungicide trials as well,
leading to many label additions for important
fungicides such as etridiazol (Truban/Terrazole),
chlorothalonil (Daconil), PCNB (Terraclor),
iprodione (Chipco 26019), triflumizole
(Terraguard), and fosetyl aluminum (Aliette). This project con
registered compounds and many new experimental compounds.
Host Nutrition and Diseases
Research concerning the role of host nutrition in
severity of ornamental foliage plant diseases has been
conducted since 1982. This information is necessary to
develop an integrated approach to management of diseases.
Research efforts have concentrated on determining what
effect fertilizer rate has on a wide variety of fungal and
bacterial diseases. The role of nitrogen source and
nitrogen-potassium-phosphorous ratio have been
investigated for some diseases. Xanthomonas leaf spot
diseases of the following plants are minimized with higher
than recommended rates of fertilizer: Brassaia
actinophylla, Ficus benjamin, Hedera helix, Hibiscus
rosa-sinensis, Schefflera arboricola, and Syngonium podophyllumwn. Recently two
Pseudomonas diseases on Impatiens and Bougainvillea were found to respond in
the opposite manner. Future research will concentrate on identifying the mode
of action of fertilizer rate, balance or source in these effects on diseases of
Temperature and Diseases
Identification of the optimal temperature for development of each ornamental
disease is needed to better target pesticide usage. Many of the most common
diseases have been evaluated but further research is being conducted to fill in the
gaps in this important data.
Dr. Ann R. Chase is Professor of Plant Pathology. She started at the research center in 1979
when she completed her doctorate in Plant Pathology at the University of California at Riverside.
itinues with both
Production of Foliage Plants
C. A. Conover and R. T. Poole
The goals of this program are to identify factors affecting production, quality
and use of ornamental plants and to initiate research designed to improve
production and other practices. A major goal is to develop new best management
practices that are compatible with the environment while maintaining profitability.
This information is used to assist extension personnel in education of producers
Historically, Florida producers have grown plants on benches where leachate
from irrigation is free to drain to the surficial aquifer. During the last several
years there have been reports from many areas of the U.S. where nitrate levels
greater than 10 ppm (the federal limit for drinking water) have been found in
surficial aquifers. Until recently we have concentrated our research on
development of "Best Management Practices" (BMP's), whereby we
recommended the minimum level of fertilizer that would produce high quality
foliage plants. However, even with BMP's there is some potential for nitrate to
reach the surficial aquifer and for this reason we are examining the potential for
ebb and flow benches, where all the water/fertilizer is contained and recirculated.
Our initial research has focused on fertilizer levels and sources as well as potting
media. We are also working on algae control, since it has proven to be a major
problem. Lastly, we are in the beginning phase of working with specific diseases
in the recirculation water to determine their potential for crop damage.
Continued questions from producers about Dracaena 'Massangeana' growth
has prompted us to examine present methods of harvest, shipping and propagation
of cane. Areas of concern include stock production, type of cane harvested, level
of hormone applied, length of cane, shipping/storage temperature and potting
media. Cane utilized in this research is produced in Costa Rico and treatments
are being applied there under our supervision. We are particularly interested in
determining whether hormone levels need to vary depending on cane size or time
Those who maintain interior plantings have need for information on nutrition
and water use under interior environments. Our research in these areas has
examined the effect of light intensity on fertilizer need as well as the
influence of plant genus. We have found
surprising differences between crotons and
dieffenbachia under moderate light indoors, with
dieffenbachia requiring much higher levels of ,(
fertilizer. We have also recently determined that
large differences exist between genera in relation
to water utilized indoors. These data will be
beneficial in formulating care programs for
interior plantings that will improve interior plant
Research has established that Osmocote and
Nutricote are both excellent quality slow release
fertilizers for foliage plant production. We
continue to test new products with slow release
characteristics that will hopefully work as well or better but with lower cost. At
present we are examining a material produced with a "Reactive Layers Coating"
that may be a lower cost alternative.
Our fertilizer research has recently shown that the primary factor causing
tipburn on Spathiphyllum 'Petite' is high fertilizer level. However, the severity
of the problem can be increased if high fertilizer levels are combined with high
temperature and/or low irrigation rate.
Dr. Charles A. Conover is Center Director and Professor of Environmental Horticulture. He
completed his doctorate at the University of Georgia in Plant Science before assuming his present
position at the research center in 1971.
Dr. Richard T. Poole is Professor of Environmental Horticulture and Plant Physiologist. Dr.
Poole completed his doctorate in Ornamental Horticulture with the University of Florida and came
to the research center in 1969.
Foliage Plant Extension and
Plant Evaluation Programs
R. W. Henley
The extension program is designed to
coordinate educational activities and to transfer
technical information useful in commercial plant
producers, interiorscape professionals and
retailers of foliage plants. Some emphasis is also
given to consumer education programs.
Plant Production Technologies
In recent years considerable
effort has been made to introduce
producers to the use of bottom
SW ) R I B U A heating technologies for use in
(_ amS SE L O propagation and production of
closely spaced plants. Many
growers have adopted warm water
or hot water heating and distribution systems which place heat in the plant root
zone, a technique which permits production of difficult-to-produce plants on
relatively short schedules during the cool season. Research during the 1990-1991
season is focused on root zone heating of large, widely-spaced containerized
plants. The results of two new heating systems are encouraging.
The Florida Poly-Pot-Pack
The weight and bulk of container-grown foliage plants are a significant factor
in the cost of shipping. A soft, light weight potting medium package has been
designed which significantly reduces the amount of water and fertilizer required
finish plants with the added advantage of increasing the efficiency of shipping and
ease of post harvest handling.
The Florida Poly-Pot-Pack is a unit of high quality
potting medium prepackaged in a shape and size that can
be accommodated in commercially available decorative
containers. Plants are started in the pot-pack after
provisions are made for irrigation, drainage and plant
insertion. Plants can be grown in the pot-pack that are
of equivalent quality to plant grown in conventional '
containers. There is approximately 30 percent less water
utilized by dieffenbachia and peperomia in the pot-pack
compared to that used by the same plants in conventional, open-top containers.
Finished poly-pot-pack-grown plants are compatible with a variety of media for
repotting and most decorative container systems.
Critical evaluation of new plants during production and
utilization is essential if successful introduction of those
plants is to follow. Plant evaluation over the past 3 years
has involved approximately 30 different species and
cultivars of Ficus, most of which were commercially
/ grown at one time or another. One commercially
discarded variety of Ficus benjamin was found to have a
unique columnar habit of growth when produced under low
light intensity (1000-2500 foot candles). The columnar
plant was named 'Florida Spire'.
Current evaluation efforts are focused on the
commercial varieties of dieffenbachia. Twenty-six
varieties are being examined and compared with regard to
their vigor, growth habit, foliage color and other characteristics.
KNOW & GROW
Dr. Richard W. Henley is Professor of Environmental Horticulture. He has been with the
research center since 1973 since he completed his doctorate at the Ohio State University.
R. J. Henny
The mission of the foliage breeding program (initiated in 1976) is twofold.
One is to develop scientific information concerning the reproductive systems of
tropical foliage plants and the other involves production, testing and release of
new cultivars to Florida growers.
Much of the breeding research has involved
members of the family Araceae, including
Aglaonema, Anthurium, Dieffenbachia and
Spathiphyllum. Initial research focused on
factors affecting flowering and seed production.
One early discovery was that aroids could be
stimulated to flower with a single foliar treatment
of gibberellic acid (GA3). Use of GA3-treatments
has proven to be an invaluable aid to interspecific
hybridization by causing different species, with
unpredictable blooming periods, to flower
Secondly, it was found that high relative
humidity (RH) was required for pollen germination
and seed set in Aglaonema and Dieffenbachia.
Wrapping freshly pollinated inflorescences with
wet paper toweling and enclosing them in plastic
bags for 24 hours is a now standard procedure.
These procedures have allowed development of
many new hybrids which were used to study the
genetics of several important ornamental traits.
For example, it has been shown that the attractive
foliar variegation patterns of Aglaonema and
Dieffenbachia are controlled by single dominant nuclear genes. Inheritance of
other traits such as leaf shape, branching tendency, disease resistance or chilling
tolerance are also being studied in selected crops. Leatherleaf fern produced
from spores also have been screened for desirable cut-foliage traits.
Hybrids selected for potential release are vegetatively increased for use in
production tests. These tests include growing hybrids through a complete crop
cycle under different nutrition and light levels. Mature plants are then subjected
to shipping and postharvest tests. Following completion of these tests hybrids are
named and released to licensed Florida tissue culture labs for propagation and
distribution to growers. Six hybrids have been released using this system and
they are listed below (Table 1).
An important step in the successful introduction of new plants is critical
evaluation. Production of new foliage plants from industry under different shade
levels and using different propagation procedures often reveals considerable
insight as to the best cultural practices to follow and frequently provides
information useful in determining the true potential of specific plants. Several
species and cultivars of Ficus have been evaluated in this program. A second
stage of the evaluation process involves testing finished plants under commercial
interiorscape conditions. Interior landscaping firms in central Florida are being
utilized as cooperators for limited evaluation of selected foliage plant cultivars.
A statewide network of extension plant display and evaluation centers was
organized in 1988. Implementation of the network will benefit industry through
identification of superior plants which can be promoted and marketed more
systematically. The display dimension of the network will be of particular value
in local consumer education programs featuring plant selection and availability of
Dr. Richard J. Henny is Professor and Plant Geneticist of Environmental Horticulture. Dr.
Henny started work at the research center in 1976 upon completion of his doctoral studies in
Horticulture at the University of Minnesota.
Cultivar Release Date
Dieffenbachia 'Triumph' February 1986
Dieffenbachia 'Victory' September 1986
Dieffenbachia 'Tropic Star' September 1987
Anthuriwn 'Southern Blush' September 1987
Aglaonema 'Stripes' December 1987
Dieffenbachia 'Starry Nights' June 1988
L. S. Osborne
The ability to grow quality ornamental foliage
plants depends on the continued availability of
safe and effective pesticides. This has become a
critical problem during the past few years with
the loss of many important compounds due to
government restrictions, voluntary removal from
the market by producers, and development of
pesticide resistant strains of the target pests. In
order to help the industry preserve these valuable
resources the Entomology program has developed
research with pesticide management as the major
Biology of New Pests
Many of the major pests have had significant amounts
of data collected on their biology. However, it seems
that each year we have new pests to contend with in
ornamental foliage plant production and very little
information is available about their biology under our
production conditions. We evaluate methods to monitor
or detect the pest which entail studies on developing
traps, guidelines for trap placement, and methods to
correlate trap catch data with actual greenhouse
populations and damage. The potential damage that can
be expected from these pests will be evaluated in order
to give the grower an idea of the significance of new
pests. For pests that pose a significant threat to the
industry we will determine their developmental rates, reproductive biology and
general life history on major crops. The sweetpotato whitefly is a current
example of a "new pest". This insect has been in Florida since 1894 but was not
considered a pest until the fall of 1986. At that time, it caused significant
economic losses for ornamental producers. Currently, the sweetpotato whitefly
can be controlled but the tools we have are limited and give erratic results. These
tools are also at risk of being lost due to development of pesticide resistant
Quality ornamental plants can not be produced
without the continued availability of pesticides. We are
evaluating many new products that the manufacturers
have shown an interest in labeling for ornamentals. The
kinds of projects that we have ongoing include studies to
determine efficacy on such pests as spidermites, broad
mites, mealybugs, thrips, aphids, and whiteflies. Once
we have products that are effective at controlling specific
e pests we determine how safe they are by conducting
phytotoxicity trials. Finally, we look at the potential for
the product to be integrated with various biological
control agents that we have in culture at any given time.
The potential for developing biological control
programs for ornamental plants is being evaluated
extensively. We feel that biological control is a viable
control tactic in certain production systems. These
systems include stock beds from which propagative
material is obtained and crops in which the marketed
product is sold without the damaged tissue. The factors
that are impeding the implementation of control 0 0
programs are also being evaluated. The primary thrust 0
of the program is utilizing pathogenic organisms that can
be used in a similar fashion as traditional pesticides.
Dr. Lance S. Osborne is Associate Professor of Entomology. He completed his doctoral
research in Entomology at the University of California at Davis and joined the research center
faculty in 1980.
Cut Foliage (Florists' Greens) Research
Robert H. Stamps
Effective weed control methods, cold protection techniques that
conserve water, production systems that reduce fertilizer leaching,
ways to reduce leatherleaf fern frond postharvest wilt, means of
controlling disease and insect pests, identification of new cut foliage
crops, determination of the optimum fertilization and shade levels
for production of various crops, and assessment of crop water
requirements are some of the needs of Florida's expanding cut
foliage industry. Center researchers are conducting experiments to
find answers to these and other questions confronting this industry.
One of the biggest and most costly problems facing producers
of cut foliage crops in Florida is that of weed control. Weeds
compete with the crops for light, nutrients and water. Weeds can
also interfere with harvesting and harbor disease, insect and other
pests. Weed competition is most detrimental and hard to control
during the establishment phase of crop production which can last
for several years. A dense crop canopy can be an excellent means
of controlling weeds, but may not be possible to achieve under conditions of heavy crop
harvesting or with crops that do not form dense canopies.
Research is centered on finding effective and nonphytotoxic herbicides that do not have
undesirable environmental effects. The generation of data will help obtain registration of
promising herbicides so that they can be legally used by the cut foliage industry.
4'. 't; Most commercial cut foliage crops produced in Florida are tropical
or subtropical plants that are severely damaged or killed at the low
Temperatures normally encountered during winters in Florida. Crop
.? damage during the winter is particularly pernicious because prices and
S._ *, v Idemand are highest during the first six months of the year. Water is
"P 1 the most commonly used means of cold protection because it is the
least expensive method available. However, water cannot be used to
cold protect all cut foliage crops.
New sprinkler and orifice designs, sprinkler management strategies (icing of shadehouses)
and crop cold protection covers are being evaluated for effectiveness. One goal of this
research is to reduce the amount of water needed to protect crops from cold temperatures.
Another goal is to find economical methods of cold protecting crops for which the use of
water is not a viable option. Research is being conducted at research shadehouses located
in Volusia and Putnam counties.
One of the most important characteristics of a cut foliage crop is the
ability for it to hold up in an arrangement as long as the flowers do. Some
cut foliage crops easily outlast the flowers without any human intercession;
however, others may require special treatment. Additionally, suppression of
disease development during shipping and storage can be a problem, especially
when the crop is not handled properly after it leaves the grower's operation.
Antitranspirant and preservative solutions are being evaluated for their
ability to prolong the vase life of cut foliage crops. Effects of production 0o .
factors such as light and fertilizer levels on vase life are also being monitored.
The influences of microclimate on crop development and subsequent
durability are another area of active research.
The introduction of new cut foliage is an essential element for
keeping the industry vital and growing. Many floral designers are
interested in obtaining new foliage that can contribute variety to their
Plants are continually being evaluated for their suitability as cut
foliage crops. Evaluation criteria include vase life, yield, susceptibility
to pests and diseases, and potential demand for the cut foliage by florists.
Once it has been ascertained that a crop has adequate Light
shipping and vase life characteristics for cut foliage use,
production techniques must be developed that will allow the Fertilizer
crop to be grown economically and with suitable quality.
Research is being conducted to determine the effects of the
production environment on yield and vase life of cut foliage.
Light and fertilizer levels are two of the production elements being studied. New
shadehouse coverings are being evaluated for their effects on cut foliage crops. Crop water
and nitrogen requirements are being determined to allow precise irrigation and fertilization
scheduling in efforts to minimize water use, production costs and potentials for ground water
contamination. Various irrigation scheduling techniques are being evaluated for use on cut
foliage crops growing in shadehouses.
Dr. Robert H. Stamps is Associate Professor of Environmental Horticulture and Cut Foliage Extension Speciahst. He has been
with the research center since 1979 and assumed his present position in 1984 when he completed his doctorate in Horticulture at
the University of Florida.
- The Institute of Food and Agricultural Sciences, University of Florida.
- A statewide organization dedicated to teaching, research and extension.
- Faculty located in Gainesville and at 23 Research and Education Centers and
67 County Extension offices throughout the state.
-A partnership in food and agriculture, and natural and renewable resource
research and education, funded by state, federal and local government, and
by gifts and grants from individuals, foundations, government and industry.
- An organization whose mission is:
Educating students in the food and agricultural industry, and related
Strengthening Florida's diverse food and agricultural industry and its
environments through research.
Enhancing, for all Floridians, the application of research and knowledge
to improve the quality of life statewide through IFAS Extension
UNIVERSITY OF FLORIDA
The Institute of Food and Agricultural Sciences is an Equal Opportunity
Employment-Affirmative Action Employer authorized to provide research,
educational information and other services only to individuals and
institutions that function without regard to race, color, sex, or national