APOPKA ARC Research Report RH-1973-5
APOPKA FOLIAGE FIELD DAY
AGRICULTURAL RESEARCH CENTER APOF
Institute of Food and Agricultural Sci
Friday, June 1, 1973
11 :, a.m.
- Welcome and Introductions
Henry F. Swanson, County Extension Director, Orange County
Review John W. Sites, Dean for Research, IFAS, University
Address Kenneth R. Tefertiller, Vice President Agricultural
Affairs, IFAS, University of Florida
- Research Highlights
Charles A. Conover, Assoc. Horticulturist and Center Director,
Nutrition and Culture
Richard T. Poole, Assoc. Plant Physiologist, Soil Media and
James F. Knauss, Asst. Plant Pathologist, Disease Control
Ronald A. Hamlen, Asst. Entomologist, Insect and Nematode Control
Larry N. Shaw, Asst. Agricultural Engineer, Equipment Design
- FNGA Sponsored Barbecue $3.00/person
- Dedication of FNGA Sponsored Indexing Greenhouse James F.
Griffin, Jr., Executive Vice President FNGA
- Tours of Agricultural Research Center and Experimental Plots
TABLE OF CONTENTS
Research Project RH-01615
Properties of natural and synthetic media and resulting
effects on production of ornamental plants 4
Research Project RH-01107
Macro-element nutrition of certain floricultural crops 6
Research Project RH-01069
The effects of photoperiod and temperature on growth and
flowering of certain floricultural crops 8
Research Project RH-01189
Morphological and biochemical effects of growth regulators
on flowering plants 10
Research Project RH-01555
Weed control for ornamental plants 11
Research Project RH-01021
Nature, cause and control of diseases of tropical foliage
Research Project RH-01518
Diseases of ornamental plants caused by soil-borne pathogens 15
Research Project RH-01353
Biology and control of insects and related pests on
ornamental plants 18
Research Project (New Project)
Biology and control of nematodes affecting ornamental crops 18
Research Center Tour Guide
The Agricultural Research Center at Apopka came into existence
primarily through the efforts of local nurserymen and agricultural
leaders who recognized the need for research on problems associated
with commercial foliage plant production.
Orange County purchased 18 acres of land and donated it to the
University of Florida for the site. Building funds for the office
building, greenhouse, and storage building were appropriated by the
1965 State Legislature. 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
Research facilities at this center have been designed to closely
duplicate grower conditions with plants grown under shade cloth, slat,
fiberglass and glass.
The primary objective of this ARC is to conduct research and
assist in State Extension Activities on commercial ornamental
horticultural crops of Florida. The major industries involved are
foliage, cut-ferns, caladiums and certain woody ornamentals such as
azaleas and gardenias.
Five faculty positions and areas of specialization are presently
located at the Agricultural Research Center Apopka, these are:
1. Dr. Charles A. Conover Assoc. Ornamental Horticulturist and
Center Director Administration, Soils & Nutrition.
2. Dr. R. A. Hamlen Asst. Entomologist Insect and Nematode
Pests of Ornamentals.
3. Dr. J. F. Knauss Asst. Plant Pathologist Ornamental Plant
4. Dr. R. T. Poole Assoc. Plant Physiologist Horticulture and
Physiology of Ornamentals.
5. Open Position Asst. Ornamentals Extension Specialist, Ornamental
Horticulture Extension Foliage.
Information provided in this report summarizes active research
projects, research underway and research published since establishment of
ARC-A. For information about specific research reports, please contact
the research investigators listed for the project. Copies of many research
reports are available through your county agents office, or the extension
secretary at this Research Center. In the listings of published information,
those numbers proceeded by a (*) are out of print and not available at this
HORTICULTURAL RESEARCH PROGRAMS
C. A. Conover and R. T. Poole
Research in this area has as its objective the development of new
or improved methods of increasing yield and quality of foliage, fern and
caladiums. Major research areas include nutrition, media, photoperiod,
light intensity, temperature, growth regulators, herbicides and certain
cultural changes such as irrigation methods and frequency.
Immediate plans are to develop optimum cultural recommendations for
the major foliage crops, fern and caladiums. Future plans will include
development of new crops and methods of changing the appearance of crops
Research Project RH-01615
Title: Properties of natural and synthetic media and resulting effects on
production of ornamental plants.
1. Influence of soil media and irrigation frequency on growth of Aechmea
fasciata. Eight media are being compared at two irrigation frequencies.
Media components include combinations of imported peat, native peat,
cypress shavings, sand, pine bark, fir bark and water hyacinths.
2. Influence of soil media and ammonium nitrate level on Philodendron
selloum grown with 18-6-12 Osmocote. Ten soil media were treated with
3 levels of ammonium nitrate to provide initial nitrogen in mixes con-
taining wide carbon:nitrogen ratios. Soil mixtures contain combinations
of water hyacinths, pine shavings, cypress shavings, pine bark and
3. Effect of soil media and mist on chlorosis and necrosis of Dracaena
'Warneckii'. A continuation of research on influence of media on
uptake of fluoride. Soil mixtures consist of German peat, Fibrex bark,
Turface, Terragreen and pine bark with cuttings either misted 15 sec/
30 min or not misted.
4. Influence of soil media and calcium supplement on chlorosis and necrosis
of Dracaena 'Warneckii'. Treatments include 2 soil media and 2 levels
each of dolomite and calcium hydroxide in factorial combination.
1. Poole, R. T. 1969. Rooting response of four ornamental species propagated
in various media. Proc. Fla. State Hort. Soc. 82:393-397. Also Florida
Foliage Grower 7(2):1-5.
2. Conover, C. A. and R. T. Poole.
Foliage Grower 7(4):1-8.
1970. Foliage plant propagation.
3. Conover, C. A. and R. T. Poole. 1970. Methods
plants. Florida Foliage Grower 7(5):1-4.
*4. Conover, C. A. and R. T. Poole. 1970. Foliage
Maintenance, October, 1970. pg. 27-29.
5. Poole, R. T., D. B. McConnell and J. F. Knauss.
Dracaena 'Baby Doll'. Florida Foliage Grower
of propagating foliage
plant propagation. Gr<
1971. Leaf necrosis of
6. Conover, C. A. and R. T. Poole. 1971. Influence of fluoride on foliar
necrosis of Cordyline terminalis 'Baby Doll' during propagation. Proc.
Fla. State Hort. Soc. 84:380-383. Also Proc. SNA Research Conf. 17:24.
*7. Poole, R. T., D. B. McConnell an
propagation media for foliage
8. Poole, R. T. and W. E. Waters.
for growth of foliage plants.
9. Conover, C. A. and R. T. Poole.
of Cordyline terminalis 'Baby
Also Mimeo Report ARC-Apopka 1
Waters. 1971. Evaluation of
Proc. Assoc. Sou. Agri. Workers
1972. Evaluation of various potting media
Proc. Fla. State Hort. Soc. 85:395-398.
1972. Production of high quality plants
Doll'. Florida Foliage Grower 9(8):1-2.
972-5, 3 pp.
10. McConnell, D. B., W. E. Waters and R. T. Poole. 1972.
properties of several peat sources. Florida Foliage
Also The Florida Nurseryman 17(11):9.
11. Poole, R. T. and W. E. Waters. 1972. Media for potted foliage plants.
Florida Foliage Grower 9(7):5-7. Also The Florida Nurseryman 17(3):12-13.
12. Poole, R. T. and W. E. Waters. 1972.
Flower Grower 9(6):6-7.
Media for potted plants.
*13. Conover, C. A. and R. T. Poole. 1972. Factors
necrosis of Cordyline terminalis 'Baby Doll'.
Workers 69:156 (Abstr.).
*14. Poole, R. T. and C. A. Conover. 1972. Necrosi
'Baby Doll' as influenced by soluble fluoride
influencing fluoride induced
Proc. Assoc. Sou. Agri.
s of Cordyline terminalis
HortScience 7:320 (Abstr.).
Research Project RH-01107
Title: Macro-element nutrition of certain floricultural crops.
1. Influence of three levels each of nitrogen, phosphorus and potassium
in factorial combination on growth and flowering of Aechmea fasciata.
Plants will be graded for size, number leaves, foliage color and
2. Effects of dolomite, sulphur, manganese and iron on red edge of
leatherleaf fern. Indications from numerous tissue analyses of
leatherleaf indicate a micronutrient toxicity may be responsible for
this physiological disorder. The experiment includes variable pH with
sulphur or dolomite, 3 shade levels and 2 levels each of manganese
3. Influence of nutritional level on chilling injury of Sansevieria
zeylanica. Five levels of nitrogen-phosphorus-potassium are being
checked against chilling injury at 350F.
4. Influence of nitrogen and potassium on propagation of Sansevieria
zeylanica. Three levels of nitrogen and two of potassium are being
compared with yield or marketable rhizomes produced from leaf sections.
5. Influence of nutritional level on yield and keeping quality of leather-
leaf fern. Treatments consist of 4 nitrogen and 2 potassium levels in
factorial combination. Keeping quality is being determined periodically
throughout the year.
6. Influence of nutrition and watering frequency on acclimization of
foliage to interior conditions. Dieffenbachia picta and Aphelandra
squarrosa were grown under 3 nutritional and 4 irrigation regimes
prior to transfer to 75 fc and 2 watering levels.
7. The relationship of nutrition to growth and shedding of Asparagus
plumosa. Treatments consist of peat amended and non-amended soil and
2 levels each of nitrogen and potassium. Data will be collected
periodically during the year.
8. Influence of nutrition and tuber treatment on growth and color of
Caladium 'Candidum' and C. 'Attala'. Treatments include 3 nutritional
levels, tuber central eye removed or not and tuber planted inverted
9. Influence of shade level and nutrition in production areas and
subsequent watering frequency under interior conditions on acclimization
of Dieffenbachia amoena. Treatments include 3 shade and 3 nutritional
levels and 2 watering frequencies.
10. Influence of dolomite and boron on
'Warneckii'. Treatments include 3
factorial combination to determine
toxicity which causes chlorosis and
deficiency which may be responsible
necrosis and cracking of Dracaena
boron and 3 dolomite levels in
influence on apparent fluoride
Inecrosis and possible boron
11. Influence of liming materials on necrosis of Cordyline 'Baby Doll'
cuttings. Peat is amended with various levels of Ca(OH)2 and dolomite
in an attempt to reduce necrosis of 'Baby Doll' during propagation.
Both materials reduce chlorosis caused by fluoride in irrigation water.
12. Influence of dolomite and Perk on propagation of Aphelandra squarrosa
and Aglaonema 'Fransher'. Perk 0, 10 and 20 lbs/400 sq ft and dolomite
0, 40 and 80 lbs/400 sq ft were incorporated in peat to determine the
influence of these materials on rooting and growth. Dolomite appears
to aid root development.
1. Conover, C. A. 1969.
Foliage stock plant production.
2. Conover, C. A. 1969. Foliage stock plant production weed, disease and
insect control. Florida Foliage Grower 6(6):1-7.
3. Conover, C. A. 1972. Influence of nutrition on foliage quality and
longevity. ARC-A Mimeo 72-3, 5 p. Also Florida Foliage Grower 9(3):1-4.
4. Conover, C. A.
1972. Fertilization practices for foliage plant stock
Florida Foliage Grower 9(3):6-8.
5. Conover, C. A. and R. T. Poole. 1972. Influence of
nutritional amendments on selected foliage plants.
Proc. Fla. State Hort.
*6. Conover, C. A. and R. T. Poole. 1972. Influence of light and nutritional
level on growth and yield of Scindapsus aureus, Cordyline terminalis
'Baby Doll' and Dieffenbachia exotica. Proc. Am. Soc. Hort. Sci.,
Tropical Region 16:(In Press).
7. Poole, R. T. and W. E. Waters. 1972. Production of container grown azaleas
under slat shade using Osmocote slow release fertilizer. Florida Foliage
8. Conover, C. A. and R. T. Poole. 1972. Fertilization practices for
foliage plant propagation. Florida Foliage Grower 9(3):4-5.
9. Poole, R. T., D. B. McConnell and W. E. Waters. 1972. Evaluation of
four cultural practices on leatherleaf fern production. Florida Foliage
*10. Conover, C. A. and R. T. Poole. 1972. Influence of light intensity and
fertilizer source and level on growth, quality and tissue content of
Philodendron oxycardium. HortScience 7:348 (Abstr.).
*11. Conover, C. A. and R. T. Poole. 1972. Influence of nutrition, scooping
and planting position on growth of potted caladiums. Proc. SNA
Research Conf. 17:24-25 (Abstr.).
12. Conover, C. A. and R. T. Poole. 1973. Factors influencing micronutrient
use in tropical foliage production. Apopka ARC Research Report RH73-
1. 5 p.
13. Poole, R. T. and C. A. Conover. 1973. Factors influencing forcing of
caladiums. Apopka ARC Research Report RH73-3. 6 p.
Research Project RH-01069
Title: The effects of photoperiod and temperature on growth and flowering
of certain floricultural crops.
1. Influence of photoperiod and shade level on flowering and leaf
characteristics of Aphelandra. These plants do not appear to be
photoperiodic but flowering and leaf characteristics are determined
by light intensity.
2. Growth of plants under natural daylight plus supplemental light during
the night. Response of various plants to night time lighting is being
3. Time in storage, temperature during storage and propagation and their
influence on germination of 'Neanthe Bella' seed. Increased propagation
temperature reduces germination time and storage past 4 weeks reduces
4. Influence of shade level and rhizome type at planting on yield of
leatherleaf fern. Different size rhizomes with or without fronds
were planted under various shade levels to determine time of coverage
and influence on subsequent yield.
5. Influence of light and nutrition on color intensity of foliage of
Caladium bicolor 'Candidum' and 'Attala'. Treatments include 40, 60
and 80 percent shade and 3 nutritional levels.
6. Influence of shade level, nutrition and soil media on growth and color
of Chrsalidocarpus lutescens. Treatments include 3 shade and 5
nutritional levels on 2 soil media.
7. Growth and propagation of Aglaonema, Peperomia and Maranta as
influenced by nutrition and shade levels. The plants are grown under
60 or 80 percent shade and fertilized with Osmocote 14-14-14 at
annual rates of 250, 1250 or 2250 pounds per acre of actual nitrogen.
Best growth of Peperomia and Maranta was under 60 percent, Aglaonema
8. Preconditioning of Schefflera and Ficus. Plants grown under full sun
were placed under either 40 or 80 percent shade and kept under this
condition for 1, 2 or 3 months, then moved to 25, 75 or 125 foot
candles. Schefflera appears to be a better plant under low light
conditions than Ficus. Both plants did poorly under 25 foot candles.
Several Ficus died at this low light intensity. However, some growth
occurred on- pants under 125 foot candles. Ficus can become acclimated
in approximately 4 weeks under 80 percent sha-e.
*1. Poole, R. T. 1970. Temperature and plant production. Florida Foliage
Flash. Vol. IX No. 9.
2. Poole, R. T. and W. E. Waters. 1971. The influence of elevated medium
temperatures upon development of cuttings and seeds of tropical indoor
foliage plants. HortScience 6:463-464.
3. Poole, R. T. 1971. Flowering of Christmas cactus as influenced by
nyctoperiod regimes. Proc. Fla. State Hort. Soc. 84:410-413.
4. Poole, R. T., D. B. McConnell and W. E. Waters. 1971. Production of
leatherleaf fern as influenced by several cultural factors. Proc. Amer.
Soc. Hort. Sci., Tropical Region 15:223-228.
*5. Poole, R. T. and C. A. Conover. 1972. Influence of soil temperature,
tuber treatment and shade level on growth of potted caladiums. Proc.
Assoc. Sou. Agri. Workers 69:156 (Abstr.).
*6. Conover, C. A. and R. T. Poole. 1973. Ficus benjamin leaf drop.
Florists Review 151(3925):29,67,68.
Research Project RH-01189
Title: Morphological and biochemical effects of growth regulators on
1. 'Neanthe Bella' germination as influenced by growth regulators. PBA,
ethephon, Maintain and ancymidol were used as a soak prior to planting
in an effort to hasten seed germination. PBA appears to reduce
germination time slightly.
2. Influence of leaf variegation on variegation of adjacent axial bud
breaks. Leaves were selected for degree of variegation and the
shoot was pruned immediately above the leaf. Subsequent shoot growth
will be evaluated.
3. Leaf drop of leatherleaf fern. Quercitin, cinnamic acid, ethephon and
abscissic acid were applied to fern to determine the causal agent of
4. Growth regulators and caladium tuber production. B-9, chlormequat and
ethephon will be applied to caladiums to study the effect of these
growth regulators on tuber size. Two previous experiments show all
these materials increase tuber size of red varieties, but not 'Candidum'.
1. Poole, R. T. 1970. Growth retardants and tropical ornamentals. Proc.
Amer. Soc. Hort. Sci., Tropical Region 14:268-271.
*2. Poole, R. T. 1970. The influence of growth regulators on plant
elongation and rooting response of foliage plants. Proc. Assoc. Sou.
Agric. Workers 67:164 (Abstr.).
3. Conover, C. A. and J. N. Joiner. 1971. Effects of manual and chemical
pruning methods on growth of forcing azaleas. Proc. Fla. State Hort.
4. McConnell, D. B. and R. T. Poole. 1972. Vegetative growth modification
of Scindapsus aureus by ancymidol and PBA. Proc. Fla. State Hort. Soc.
*5. McConnell, D. B. and R. T. Poole. 1972. Effect of Sandoz 6706 on
various foliage plants. Proc. Assoc. Sou. Agri. Workers 69:157 (Abstr.).
Research Project RH-01555
Title: Weed control for ornamental plants.
1. Influence of weed competition on yield of Philodendron oxycardium.
Plots will be hand weeded at various intervals, some every 2 months,
others every 3 months, 6 months or annually. Yield will be compared
to plots treated with chemical herbicides.
2. Weed control of various herbicides and their effects on production
of leatherleaf fern. Simazine, GS-13638, Dacthal, bark-Dacthal and
MC-4379 have been applied to test their effectiveness and the tolerance
of fern to these herbicides.
*1. Poole, R. T. and W. E. Waters. 1972. The influence
stock plant production of several foliage species.
Hort. Sci., Tropical Region 16: (In Press).
of herbicides on
Proc. Am. Soc.
2. Poole, R. T., W. E. Waters and A. J. Pate. 1972. Herbicides and the
foliage industry. I. Stock beds. Florida Foliage Grower 9(2):1-6.
Also Mimeo Report ARC-Apopka 1972-1. 7 p.
3. Poole, R. T.,
C. A. Conover and W. E. Waters. 1972. Herbicides and
industry. II. Non Crop Areas. Florida Foliage Grower
Also Mimeo Report ARC-Apopka 1972-2. 5 p.
1. Harrison, D. S., and C. A. Conover.
leatherleaf and plumosus ferns.
S1970. Irrigation designs for
Agric. Eng. Mimeo Report 70-7.
*2. Conover, C. A. and L. L. Loadholtz. 1970. Leatherleaf fern production
in Florida. Orn. Hort. Report 70-1., Univ. of Fla.
*3. Conover, C. A., T. J. Sheehan and D. B. McConnell.
Grown Foliage Plants. Fla. Exp. Sta. Bull. 746.
4. Conover, C. A. and R. T. Poole.
Rico. Florida Foliage Grower
1971. The foliage industry of Puerto
5. Conover, C. A. 1972. Getting the most from foliage plants in the
retail shop. Florists Review 150 (3891):16,17,35,36. Also ARC-A
Mimeo No. 72-6. 5 p. Also Florida Foliage Grower 9(8):3-T.
*6. Conover, C. A. 1972. The ornamental horticulture industries, research
and teaching programs of the United States Gulf Coast Region. Proc.
of the Conf. on Horticultural Development in the Caribbean, Maturin,
Venezuela, March 12-15, 1972. pp 95-109.
7. Conover, C. A. 1972. Greenhouse production
Southern United States. ARC-A Mimeo 72-7,
Foliage Grower 9(11):1-7.
*8. McConnell, D. B., C. A. Conover and
plants, selection, care and use.
Ext. Serv. May, pp. 3-9.
of potted foliage in the
10 p. Also Florida
T. J. Sheehan. 1973.
Landscape Notes, Texas
PLANT PATHOLOGY RESEARCH PROGRAMS
J. F. Knauss
Research programs have in the past and will continue to have as
their objective the identification, description and solution of disease
problems faced by the Florida foliage, fern and caladium growers. Major
emphasis in the past has been placed on safe and effective methods of
chemical control. Present and future plans call for further chemical
evaluations for disease control along with new programs designed to
develop and evaluate cultural and biological methods of disease control.
It is the desire of the pathology section to eventually develop
programmed systems for disease control which will integrate the best
chemical and non-chemical methods of disease control.
Research Project RH-01021
Title: Nature, cause and control of diseases of tropical foliage plants.
1. Bactericide Evaluation Plots. Prospective bactericides alone and
in combination evaluated as protective sprays for the control of
Erwinia chrysanthemi on Philodendron selloum and control of
Xanthomonas vitians on Syngonium podophyllum 'Green Gold'. Sprays
are applied prior to inoculation with the pathogen.
2. Cultural and Chemical Control of Foliar Plant Pathogens. Two types
of irrigation, overhead and surface watering, evaluated in the presence
and absence of protective bactericidal sprays for their effect upon
the diseases of Philodendron oxycardium and Syngonium podophyllum
caused by Xanthomonas dieffenbachiae and Xanthomonas vitians respectively.
3. New Disease, Bromeliad Leaf Spot. Studies on the identification and
control of the cause of this previously-undescribed disease of
4. Bacterial Blight of Syngonium. These studies are long term to
determine whether previously non-infected Syngonium podophyllum will
become systemically infected when foliar-inoculated with Xanthomonas
vitians. Previous tests indicate this pathogen will cause cutting
decay but whether it is systemic (persists within) the plant is unknown.
5. Leatherleaf Evaluation Plots. These plots will be employed to
determine the efficacy and phytotoxicity of candidate foliar fungicides
when employed for the control of foliar pathogens of leatherleaf fern.
6. Production of "Disease-Free" Stocks of Foliage Plants. In the new
indexing greenhouse methods proven effective to eliminate plant
pathogens from foliage plants will be employed to develop "disease-
free" stocks of foliage plants. These stocks will be eventually
released through appropriate means to foliage plant growers to
replenish presently diseased stock sources. The plant varieties to
be indexed first are Syngonium spp. and Dieffenbachia spp.
1. Knauss, J. F. and C. Wehlburg. 1969. The distribution and pathogenicity
of Erwinia chrysanthemi Burkholder et al. to Syngonium podophyllum
Schott. Proc. Fa. State Hort. Soc. 82:370-373.
2. Knauss, J. F. 1970. Ascochyta leaf spot, a new disease of leatherleaf
fern, Polystichum adiantiforme. Proc. Trop. Reg. Amer. Soc. Hort. Sci.
3. Knauss, J. F. and S. A. Alfieri, Jr. 1970. Dactylaria leaf spot, a
new disease of Philodendron oxycardium Schott. Proc. Fla. State
Hort. Soc. 83:441-444. Also: Florida Foliage Grower 8(4):1-2.
*4. Knauss, J. F., W. E. Waters and R. T. Poole. 1970. Bacterial leaf
spot and tipburn of Philodendron oxycardium (cordatum) caused by
Xanthomonas dieffenbachiae. The Florida Nurseryman 15(12):5. Also:
Florida Foliage Grower 8(1):11.
5. Knauss, J. F. 1971. Fusarium stem rot, a previously unreported
disease of unrooted cuttings of Dracaena. Proc. Trop. Region Amer.
Soc. Hort. Sci. 15:208-215.
6. Knauss, J. F., W. E. Waters and R. T. Poole. 1971. The evaluation
of bactericide and bactericide combinations for the control of
bacterial leaf spot and tipburn of Philodendron oxycardium incited
by Xanthomonas dieffenbachiae. Proc. Fla. State Hort. Soc. 84:423-428.
7. Knauss, J. F. 1971. The phytotoxicity of seventeen miticides applied
as repeated weekly sprays under slat shed conditions to five foliage
plant species. Proc. Fla. State Hort. Soc. 84:428-432.
8. Knauss, J. F. 1971. Plant Disease Series. I. Introduction. Florida
Foliage Grower 8(3):1,2. Also: Florist and Nursery Exchange 155(25):3
And The Florida Nurseryman 16T6):12.
9. Knauss, J. F. 1971. Plant Disease Series. II. Plant Pathogens.
What they are, where they come from and how they spread. Florida
Foliage Grower 8(5):1-3. Also: The Florida Nurseryman 16(11):12,13.
10. Knauss, J. F. 1971. Plant Disease Series. III. Foliage plant diseases.
How they develop, methods for their control. Florida Foliage Grower
8(6):1-3. Also: The Florida Nurseryman 16(12):12,13,25.
11. Knauss, J. F. 1971. Suggestions for the control of some common
diseases of foliage plants. Agr. Res. Center Apopka, Mimeo 71-2:20 p.
12. Poole, R. T.,
D. B. McConnell and J. F. Knauss. 1971. Leaf necrosis
'Baby Doll'. Florida Foliage Grower 8(1):13.
13. Knauss, J. F. 1972. Foliar blight of
Colletotrichum gloeosporioides. Pl.
Dionaea muscipula incited by
Dis. Reptr. 56:391-393.
14. Knauss, J. F. 1972. Resistance of Xanthomonas dieffenbachiae isolates
to streptomycin. Pl. Dis. Reptr. 56:394-397
*15. Hartman, R. D., F. W. Zettler, J. F. Knauss and Eleanor Hawkins. 1972.
Seed propagation of caladium and dieffenbachia. Proc. Fla. State
Hort. Soc. 85:(In Press).
*16. Knauss, J. F. 1973.
Review: (In Press).
Common diseases of foliage plants. Florists
17. Knauss, J. F., C. A. Conover and R. A. Hamlen. 1973.
application rates of fungicides and insecticides for
pesticide applications on foliage plants. Agr. Res.
Research Report RH-1973-4:6 p.
Research Project RH-01518
Title: Diseases of ornamental plants caused by soil-borne pathogens.
1. Control of Pythium Blight of Caladium. Experiment conducted under
field-simulated conditions to determine the efficacy and potential
phytotoxicity of candidate soil fungicides for the control of
Pythium myriotylum. Fungicides applied in-row at time of planting
and after 2 months growth as a 2 inch band treatment. Caladium
variety employed was 'Freida Hemple'.
2. Soil Fungicide Phytotoxicity Evaluation. Applications by soil
incorporation, drenches and sprays. To be usable, soil fungicides
must be both effective in control of the pathogen and not
phytotoxic to the plant. The major emphasis in this experiment is
to determine the limits of phytotoxicity when the fungicides are
incorporated alone or in combination into the planting media prior
to planting. Effective and safe soil incorporation of fungicides
will aid a great deal in controlling soil-borne pathogens where
drench treatments are not possible.
3. Control of Phytophthora Blight. Members of the fungal genus
Phytophthora are among the most destructive soil-boren pathogens of
many of the ornamental crops grown in Florida. Although this group
is closely related to the genus Pythium, it is generally not as
easily controlled by fungicide application. These experiments have
been designed to coordinate with #2 above and determine the efficacy
of the fungicides applied by soil incorporation, drench or spray
for the control of this pathogen group.
4. Control of Caladium Tuber Decay. Tuber or tuber piece decay may
effect field production of this crop. Several genera of fungi and
one bacterial genus have been implicated in both field and storage
decay of this crop. This experiment employs fungicide, bactericide
and heat treatment alone and in combination for the control of a
Fusarium sp. which causes one of the tuber decays. Caladium variety
5. New Disease, Root Rot of Myriocladus. Studies into the identification
and control of the cause of this previously-undescribed disease of
Asparagus retrofraxus (myriocladus).
1. Alfieri, S. A. and J. F. Knauss. 1970. Southern blight of Schefflera.
Proc. Fla. State Hort. Soc. 83:432-435. Also: Florida Foliage
2. Knauss, J. F. 1971. Rhizoctonia blight of 'Florida Ruffle' fern and
its control. Pl. Dis. Reptr. 55(7):614-616.
3. Knauss, J. F. 1972. Description and control of Pythium root rot on
two foliage plant species. Pl. Dis. Reptr. 56:211-215.
4. Knauss, J. F. 1972. Field evaluation of several soil fungicides for
control of Scindapsus aureus cutting decay incited by Pythium splendens
Braun. P1. Dis. Reptr. 56:1074-1077.
5. Knauss, J. F. 1972.
fungal pathogens of
Mimeo 72-4:15 p.
the control of soil-borne
Agr. Res. Center Apopka
*6. Knauss, J. F. 1972. Description and control of the rapid cutting
decay of Scindapsus aureus incited by Erwinia carotovora. Proc.
Fla. State Hort Soc. 85:(In Press).
*7. Alfieri, S. A., Jr.
85: (In Press).
and J. F. Knauss. 1972.
by Sclerotium rolfsii.
;, J. F. 1973. Description and control
foliage plant species incited by Rhizo
Dis. Reptr. 57:222-225.
Stem and leaf rot of
Proc. Fla. State Hort. Soc.
1 of a cutting decay of
ctonia solani Kuehn.
9. Knauss, J. F. 1973. Suggestions for caladium disease control.
ARC Research Report RH73-2:5 p.
ENTOMOLOGY AND NEMATOLOGY RESEARCH PROGRAMS
R. A. Hamlen
The newly established Entomology and Nematology research program
is now getting underway with the addition of a new Entomologist-
Nematologist on May 1, 1973. The objectives of this program will be to
identify, describe and solve the insect and nematode problems encountered
by the Florida foliage, fern and caladium growers. Presently, major
emphasis is being placed on the selection and development of safe and
effective means of chemical control.
Future objectives will include the continued identification of insect
and nematode problems and eventually the evaluation of integrated programs
of chemical and non-chemical means of pest control.
Research Project RH-01353
Title: Biology and control of insects and related pests on ornamental plants.
Specific Research Areas:
1. Determine the important pestsand their prevalence on foliage, cut
fern and caladiums.
2. Study the seasonal history, biology and ecology of the pests.
3. Develop efficient and effective programs for their control. This phase
will initially focus on the evaluation of insecticides and miticides
for effectiveness and phytotoxicity on foliage, cut fern and caladiums.
Research Project (New Project)
Title: Biology and control of nematodes affecting ornamental crops.
Specific Research Areas:
1. Determination of the pathogenicity of specific nematodes against
selected foliage, cut fern and caladium species.
2. Evaluation of newly developed nematicides for effectiveness and
phytotoxicity on foliage, cut fern and caladiums.
3. Monitoring of nematode populations existing with selected foliage,
cut fern and caladium species through regularly sampling of infested
AGRICULTURAL RESEARCH CENTER APOPKA
1 = Office Building
2 = Pathology Greenhouse
3 = CO2 Greenhouse
4 = Slat Shed
5 = Plant Conditioning Laboratory