Historic note
 Title Page

Group Title: Homestead AREC research report - University of Florida Agricultural Research and Education Center, ;no. SB78-1
Title: A history of ornamentals research at AREC - Homestead
Full Citation
Permanent Link: http://ufdc.ufl.edu/UF00067821/00001
 Material Information
Title: A history of ornamentals research at AREC - Homestead
Series Title: Homestead AREC research report
Physical Description: 4 leaves : ; 28 cm.
Language: English
Creator: Marlatt, Robert B ( Robert Bruce ), 1920-
Agricultural Research and Education Center, Homestead
Publisher: University of Florida, Agricultural Research and Education Center
Place of Publication: Homestead Fla
Publication Date: 1978
Subject: Plants, Ornamental -- Research -- Florida   ( lcsh )
Genre: government publication (state, provincial, terriorial, dependent)   ( marcgt )
non-fiction   ( marcgt )
Statement of Responsibility: Robert B. Marlatt.
General Note: "February 1978."
General Note: Cover title.
 Record Information
Bibliographic ID: UF00067821
Volume ID: VID00001
Source Institution: University of Florida
Rights Management: All rights reserved by the source institution and holding location.
Resource Identifier: oclc - 72477195

Table of Contents
    Historic note
        Historic note
    Title Page
        Title page
        Page 1
        Page 2
        Page 3
        Page 4
Full Text


The publications in this collection do
not reflect current scientific knowledge
or recommendations. These texts
represent the historic publishing
record of the Institute for Food and
Agricultural Sciences and should be
used only to trace the historic work of
the Institute and its staff. Current IFAS
research may be found on the
Electronic Data Information Source

site maintained by the Florida
Cooperative Extension Service.

Copyright 2005, Board of Trustees, University
of Florida







Homestead AREC Research Report SB78-1 February 21, 1978

A History of Ornamentals Research at A*EC-Homestead

R. B. Marlatt1

i'rior to 1953 the only attention given to ornamental plants consisted of

collections for planting at the Center and a few diagnoses of diseased or infested

specimens. During 1953 Dr. R. A. Conover screened fungicides for control of

frangipani rust. By 1955 a suitable fungicide was selected and at the end of that

year accessions for the Center's collection exceeded 1,000. This work on plant

disease control marked the beginning of many outstanding contributions credited

to the Homestead researchers of ornamentals. Dr. Conover, in 1955, began search-

ing for poinsettias resistant to scab, another fungus disease. One hundred nine-

teen cultivars and seedlings of poinsettias did not reveal any plants capable of

resisting scab.

It was not until 1957 that a scientist was hired to work exclusively with

ornamentals. Dr. L. A. McFadden was asked to "work on production problems of

O ornamental plants". He subsequently surveyed nurseries in Dade County and found

they were principally producing tropical foliage plants. Coping with diseases in

this subtropical rainy area was their most serious problem. He found bacteria

rotting dieffenbachias, a fungus was decimating philodendrons and other fungi were

causing heavy losses in peperomias and spathiphyllums. There were also serious

losses of cattleya orchids, sansevierias, scheffleras and palms. The most serious

diseases of cut flowers included botrytis rot and ray blight of chrysanthemums

and phyllosticta blight of snapdragons. Dr. McFadden's first research showed that

root-knot nematodes in pothos ground beds could be controlled with a fumigant.

The severe freeze of February, 1958, ruined many of the Center's experiments

because ornamentals were generally grown in unheated structures commonly used in

the subtropical climate. McFadden found a funglcidal control for poinsettia scab.

professor, University of Florida Agricultural Research and Education Center,
Homestead 33031.


He also began in that year, however, a study of black splash disease of hibiscus,

* which remains a mystery even today. McFadden identified a bacterium that caused

severe stem rot of dieffenbachias, another problem that is still with us. During

the same year he began to emphasize research on bacterial diseases. This was a

natural choice, since he had been trained by one of the world's outstanding

scientists working with bacterial diseases.

In 1959 McFadden found a new bacterial disease of poinsettias. His research

with a bacterial disease of aglaonemas proved the culprit was the same bacterium

that rotted philodendrons. A fungus leaf spot of pothos was identified and

fungicide trials with chrysanthemums continued. Ultimately McFadden was coauthor

of a bulletin entitled "Chrysanthemum Diseases in Florida".

In 1960, an official project began at Homestead devoted entirely to diseases

of tropical foliage plants. this was particularly timely because the demand for

house plants was soon to rise steeply, outstripping the supply for many years.

The severe hurricane of 1951 damaged test plantings and destroyed about half

of the trees in the arboretum. McFadden's work continued with diseases of

poinsettias and chrysanthemums but more and more emphasis was being laced on

foliage plant diseases. Bacterial diseases of syngonium and aglaonema were also

being researched in 1962.

By 1963 fungous diseases of dieffenbachia, kalanchoe and philodendron were

no less a problem but fungicidal control was made possible through research

efforts. At that time Dr. D. 0. Wolfenbarger, working with effective insectides

and mi.icids, controlled scale insects on hibiscus and mites on roses.

Dr. J. E. Reynolds a plant pathologist, replaced McFadden in 1964 and

discovered a stem rot of neanthe bella palms. However, he left before the end of

the year. Dr. R. B. Marlatt was hired to fill the position in late 1964.

Without losing step, house plant disease research continued on fungous and

bacterial diseases of dieffenbachias and philodendrons. Dr. R. M. Baranowski

investigated the influence of an experimental miticide on chrysanthemums and roses.

Although mite control was accomplished, as so often happens with miticides, the

mites eventually became resistant to it, therefore further work on miticides was


By 1966 Marlatt became interested in several undescribed leaf diseases of

rubber plants. An experimental rubber plant grove was established for studies

and a leaf-infecting nematode was described as the cause of one leaf spot disease.

An extensive study of rose nutrition was also completed by Dr. C. W. Young.

Iropagation and culture of dieffenbachias were studied for optimum growth

by Marlatt in 1957. D. O. Wolfenbarger continued his efforts to control mites

on roses and also worked out the life cycle of a weevil on mahogany.

In 1953, a serious leaf spotting of commercially grown rubber plants existed

but harlatt could not attribute the problem to bacteria or fungi. He then began

a hydroponic nutritional study of the plant. He continued searching for the means

of migration of rubber plant leaf nematodes from soil to foliage. That same year

R. M. Baranowski tested 12 experimental riticides on six chrysanthemum varieties.

In 19S9 Marlatt finally found leaf nematodes reached rubber plant leaves by

getting into a premature grass seed stalk. When the stalk grew up to a rubber

plant leaf the worms crawled off the seed head and entered a leaf. That was the

first report of such a unique mode of infection. The control! mow the grass.

R. M. Baranowski continues his efforts to control mites on roses and scales on

orchids and was successful. Wolfenbarger also found a control for snails on

day-lilies. The hydroponic study by Marlatt revealed that the most serious leaf

spotting on rubber plant was due to potassium deficiency. The control was

successfully accomplished in a grove by Marlatt and Dr. G. Orth. The very

first proof that mangos become seriously infected by verticillium, a worldwide

fungus common to soils of Dade County, was offered by Marlatt. T. W. Young

* completed his extensive nutritional study of roses in this same year, 1970.

Another severe leaf spotting of rubber plant was found by Marlatt to be


S caused by a fungus. Another of his studies of rubber plant revealed the rate

of leaf production and general growth patterns of this tree. A search for

verticillium resistance in mango seedlings and cultivars was futile all through


In 1974 Marlatt showed that a white blotching of sansevieria leaves was due

to air temperatures of about 450 F. Decreasing nitrogen fertilizer application

decreased the chilling injury. He and Dr. W. H. ?:dings of Gainesville proved

that Natal plum, bottlebrush tree, oleander and Brazilian pepper can all be

infected by the same fungus, which caused destruction and death of many branches.

rhe growth of sansevieria was intensively examined by Marlatt in 1975 and

reported to the sansevieria producers.

In 1975 several leafspots of fiddle-leaf fig were observed, so a grove of

the trees was planted for Harlatt. He also began a hydroponic nutritional study

. for explaining the presence of areca palm leaf spots which had never yielded

fungi or bacteria.

Another big stride was made in 1976 toward helping the foliage industry.

Through the efforts of local growers, funds were raised for another large shade

house. The producers also convinced IFAS to create the position of Extension

Horticulturist, someone to advise foliage nurserymen. The position was filled

by Dr. R. L. Biamonte, who immediately began planning the new shadehouse and

surveying the needs of the now enormous tropical foliage industry in South Florida.

.hus, as house plant production increased vastly by numbers of nurseries

and expansion of established nurseries, AXEC-Homestead is also increasing its

capacity to serve the industry.

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