Resurrection: new beginnings for...
 2004 faculty evaluation time
 Indoor air pollution
 Dr. Tom Kucharek receives outstanding...
 Citrus REC, Lake Alfred news
 CREC visitor
 Following one of our own: from...
 Congratulations PLP folks!
 New PLP faces
 SPDN and SRIPMC team up to prepare...

Group Title: PLP news
Title: PLP news. Volume 8, Issue 1. Spring/Summer, 2004.
Full Citation
Permanent Link: http://ufdc.ufl.edu/UF00067320/00023
 Material Information
Title: PLP news. Volume 8, Issue 1. Spring/Summer, 2004.
Series Title: PLP news
Physical Description: Serial
Creator: Plant Pathology Department, IFAS, University of Florida
Affiliation: University of Florida -- College of Agricultural and Life Sciences -- Plant Pathology Department -- Institute of Food and Agricultural Sciences
Publisher: Plant Pathology Department, Institute of Food and Agricultural Sciences, University of Florida
Publication Date: 2004
Funding: Florida Historical Agriculture and Rural Life
 Record Information
Bibliographic ID: UF00067320
Volume ID: VID00023
Source Institution: Marston Science Library, George A. Smathers Libraries, University of Florida
Holding Location: Florida Agricultural Experiment Station, Florida Cooperative Extension Service, Florida Department of Agriculture and Consumer Services, and the Engineering and Industrial Experiment Station; Institute for Food and Agricultural Services (IFAS), University of Florida
Rights Management: All rights reserved by the source institution and holding location.

Table of Contents
    Resurrection: new beginnings for PLP 6905 field plant pathology in 2004
        Page 1
    2004 faculty evaluation time
        Page 2
        Page 3
    Indoor air pollution
        Page 4
        Page 5
        Page 6
        Page 7
    Dr. Tom Kucharek receives outstanding plant pathologist award in Tulsa
        Page 8
    Citrus REC, Lake Alfred news
        Page 9
    CREC visitor
        Page 10
    Following one of our own: from the Magic Kingdom to outer space
        Page 11
    Congratulations PLP folks!
        Page 12
    New PLP faces
        Page 13
    SPDN and SRIPMC team up to prepare for soybean rust
        Page 14
        Page 15
Full Text

* A new beginning for PLP 6905: Field Plant Pathology in Retirements, promotions, new faces, and graduations
2004 Southern Plant Disease Network (SPDN) update
* News from faculty, staff, students, alumni, and col- Safety: On the road, in the lab
leagues from around the state


From the students of the Plant '
Department to our community
Volume 8 Issue 1

The Newsletter of the Plant Pathology Department at The University of Florida

Resurrection: New Beginnings for PLP 6905

Field Plant Pathology in 2004
by Dr. D.P. "Pete" Weinga rner

Even though it seems as if most retirees in
America are moving to Florida and urbanizing the state
in their wake, Florida continues to be one of the most
agriculturally diverse states in the US. Florida's climate
varies from temperate to tropical and therefore a wide
range of crops can be grown here. The diversity of
crops, teamed with mild temperatures, generally high
relative humidity, and long periods of nighttime leaf
wetness, provides extremely favorable microclimatic
conditions for the development and spread of plant dis-
Historically, each cropping system within the
state developed its unique problems which regional
farmers were quick to recognize. Early Florida farmers
pressed local and state politicians for creation of ex-
periment stations to "service" the crops grown in their
region. The result over time was establishment of a sys-
tem of specialized experiment stations spread through-
out Florida from Jay west of Pensacola to Homestead
south of Miami. When the experiment stations were at
their peak during the 1960's and 1970's there were plant
pathologists stationed at 14 different University of Flor-
ida, IFAS Research and Education Centers (REC's).
Although there has been an effort to consolidate the
experiment stations in recent years, there are still plant
pathology programs located at nine different research
and education centers throughout the state. More than

50% of University of Florida plant pathologists are cur-
rently located at off campus centers.

Students in PLP 6905 at EREC, Belle Glade with Dr. Rick Raid.

In addition, there are numerous USDA, Florida
Department of Agriculture and Consumer Services
(DACS), and chemical industry pathology programs
located in Florida. Thus, on campus plant pathology
programs constitute less than half of the programs in
the state and students who limit their educational ex-
periences to the main campus are losing out on a great
opportunity to see the rest of the state.
Historically, applied and adaptive plant pathol-
ogy research programs were designed to provide expe-
ditious disease control methods for commercial farmers
dominated programs at off campus research centers. In
contrast, modem day off campus pathology programs
range from genomic and molecular studies at the larger



units such as the Citrus Research and Education Center
at Lake Alfred to more applied programs at the smaller
stations. Field pathology programs vary from those
studying diseases in citrus groves, to full bed plastic
mulch, to field crops, to controlled climate facilities.
(Field Pathology PLP6905) provides students with
opportunities to visit University of Florida, IFAS, off
campus Research and Education Centers and to experi-
ence "real world" plant pathology dealing with com-
mercial crop loss situations.
Field Plant Pathology was offered in 2004 for
the first time in many years. The course gave students
an opportunity to experience the diversity of Florida's
crops; to observe plant diseases in multiple production
systems ranging from vegetable, fruit, and agronomic
crops to ornamentals grown in controlled environ-
ments; and to visit with plant pathologists working with
plant diseases in several different pathosystems and to
observe research programs emphasizing all aspects of
plant pathology, from molecular and genomic projects
to fungicide spray trials. The students also had oppor-
tunities to see and compare research, extension, and
regulatory plant pathology programs at university re-
search centers, USDA and chemical industry laborato-
ries; and to observe plant diseases in commercial fields,
and to observe first hand the economic importance of
several diseases. They learned that even following exten-

2004 Faculty Evaluation Time!

sive research using modern diagnostic and molecular
tools, the etiologies of some diseases such as citrus
blight remain elusive. During the course in 2004, we
visited 15 different sites, discussed programs with 37
different faculty and support staff, and observed 126
diseases affecting 40 different host genera. Also, the
multiple hour road trips (we logged over 1300 miles
within the state) and "debriefing" during meals enabled
the students (which included DPM, Plant Pathology,
and Horticul-
ture students)
to develop a
sense of cama-
raderie centered
on plant pa-
thology and
sense of the course was that the students all came away
with a unique educational experience that they would
repeat in a heart beat. Field Pathology will be offered
again during the spring 2005 Semester. The course will
have limited enrollment and will be open on a first
come basis. Register early and don't miss out on observ-
ing diseases in crops ranging from avocado to zucchini!

I., 0 .. < II- .., P 1 ). ,.,, .. .,

Traveling the state of
Florida for faculty evaluations
might seem like a drag to some,
but believe it or not, I really look
forward to the spring semester for
this purpose. It gives me a chance
to catch up on the diverse re-
search, teaching and extension
programs of our faculty at nine
unique locations around the state.
Although a couple of REC faculty
evaluations have to be done by
phone from time to time, I do get
around to most centers at least
once a year. The driving time
ranges from 12 hrs round trip (av-
eraging 75 mph!) to Homestead
and back to about a 4 hr RT (i.e.,
Quincy, Apopka). Although the
driving can seem like a waste of

time, I rarely have time to stop
and think, and catch up on phone
calls when I am in G'ville, so there
are some good things about the
lonely and sometimes long drives.
I am including below some high-
lights from this spring's travels.


I took a little extra time in
Homestead this year, and got a
Mike Davis and his transgenic papayas
good look at Mike Davis' trans-
genic papaya, resistant to Papaya
ringspot virus. Very impressive!
The non-transformed pa-
paya are hammered with the virus.
The coat protein mediated trans-
genic papayas are resistant to
PRSV as such that resistance is
only conferred to those isolates
with very similar CP sequences.
Thus, in order to grow papaya in
Florida, one must use the Florida
PRSV CP sequences. The resis-
tant lines may also help increase
the ability to have an economically
productive papaya industry in


iNUll-[1aisiuiilcu papaya V

I also got to see Randy
Ploetz (recipient of the University
Florida Research Faculty Award
for excellence in research; congrats
Randy!) and our new Extension
Assistant Faculty member Aaron
Palmateer in his "new and im-
proved" clinic. Although retired,
Bob McMillan is consulting for
Carey Orchid and Bromeliads, and
staying busy commuting by bike
these days.

Randy Ploetz, recent UFRF awardee with
his favorite palm.

Nigel Harrison, Monica Elliott and center
director, Van Waddill with G. Wisler.

In Ft Lauderdale, I got to
hear the latest news on Lethal Yel-
lowing (LY), Nigel Harrison's
primary research program. He
was recently awarded a grant to
sequence the entire LY phyto-
plasma genome. Nigel's research
takes him all over the world where
coconut palms are grown.
Monica Elliott, now serving as
the Associate Center Director,
continues to be active in turf ex-
tension and is further developing
her research program to include
numerous serious fungal diseases
of palms. Monica is also involved
in biocontrol of invasive plant

For example, the Lygodium fern,
as beautiful as it is, is a serious pest
in Florida.
It's always a pleasure to
visit Rick Raid and Ken
Pemezny at Belle Glade to dis-
cuss their oroarams.

Ken Pemezny, Chris Waddill (Center
Director) and G. Wisler.
Their compare, Law-
rence Datnoff, is now located in
Ken continues to teach Plant Pa-
thology with Chuck Powell in Ft.
Pierce and travel the east coast
vegetable growing areas solving
disease problems. Rick stays busy
with SOAR (Save Our Agricul-
tural Roots, a program that last
year reached over one million K-
12 kids!), the barn owl project for
rodent control in sugar cane and
vegetables. The vegetable produc-
tion program is always looking at
new and unique means of control-
ling plant diseases.
Lake Alfred is our largest
center with five faculty members
(Ken Derrick, Bill Dawson, Ron
Brlansky, Pete Timmer, R.
Chung) and two associate faculty
(Dennis Lewadowski and S.
Gowda). Congratulations to Den-
nis and Gowda for their recent
promotion to associate level!
Most of you know by now that
Richard Lee has left UF for the
USDA-ARS in Riverside, Califor-
nia to direct the citrus germplasm
center there. Best of luck, Rich-
ard, in sunny CA! Ken Derrick
continues to be our head sleuth
for citrus blight, a disease that still
eludes plant pathologists. Bill
Dawson forges ahead in his pro-
gram targeted at molecular ap-
proaches to controlling Citrus
tristeza virus.
Ron Brlansky focuses his program
on exotic diseases of citrus and
insect vector relationships. Ron
has a student, Amandeep Kah-
ion, who is making progress on
his coursework in Gainesville.
Chung has a progressive program
on the molecular aspects of post
bloom fruit drop and collaborates
with Jackie Bums, a Plant Physi-

ologist, on this project. Chung
also has extension responsibilities
for citrus diseases and will
help coordinate the diagnostics of
the CREC with the Southern Plant
Diagnostic Network (SPDN). He
will have a new student starting in
the fall of 2004. Pete Timmer is
actively pursuing extension and
research on a variety of citrus dis-
eases, including black spot, post
bloom fruit drop, sweet orange
scab among others. His program
takes Pete to all ends of the earth
where citrus is grown and serves
as a walking encyclopedia on citrus

Dave Norman, Don Hopkins, and Jim
Strandberg with visitors, Gail Wisler and
Phil Harmon.
At Apopka, our Pierce's
Disease specialist, Don Hopkins,
is now serving as interim Center
Director for the second time in his
career. Don continues to pursue
biocontrol of PD with mild strain
cross protection and has a student,
Robin Oliver, working on fluo-
rescent labels for the wild type and
the cross protecting strain. Dave
Norman is working on the nu-
merous bacterial diseases of or-
namentals and molecular methods
for diagnosis and differentiation.
His former student, Ryan Dona-
hoo, is leaving to pursue a PhD.
Go, Ryan!

Jim Strandberg is always
finding some new and interesting
disease, whether it is a fungal, bac-
terial or even a viral disease. He
recently studied a new anthracnose
of dogwood, Phytophthora sp. of
Liriope, and a begomovirus of
cabbage (Cabbage leaf curl virus).
Jim is also active in the plant pa-
thology teaching program at
Apopka, and mentors a steady
stream of high school and college
In Quincy, Jim Marois is
pursuing a multi-faceted approach
to systematics in crop rotation
among sod, cotton, peanuts and
cattle. Jim has a real vision for his
program and considers the impact
of his research on our water qual-
ity and impact of his research on
the local agricultural community.
In addition, he has some fascinat-
ing developments in boll-rot of
cotton. Tim Momol has recently
been promoted to associate pro-
fessor and tenured! Way to go,
His program is primarily
dedicated to research and exten-
sion on bacterial and viral (To-
mato spotted wilt virus) diseases
of tomato, and is multidisciplinary
in its approach. Tim has also
taken on numerous responsibilities
with the Southern Plant Diagnos-
tic Network (SPDN) and is co-
chair of the national (NPDN)
teaching and education subcom-
mittee. Tim has been a huge help
and provides valuable input and
leadership in this program.
Although I did not get to
Ft Pierce this year, Chuck Powell
continues to hold his own as the
sole pathologist there. The needs
for pathology are great there, from
citrus (primarily grapefruit), orna-
mentals and vegetables. Likewise,
Pam Roberts is the only Patholo-

gist at Immokalee, where her re-
sponsibilities in extension and re-
search of citrus and vegetables
keep her busy. Pam has also been
tenured and promoted to Associ-
ate Professor and we congratulate
Pam as well! Pam has been busy
this spring and summer with trav-
els to Puerto Rico, Cuba (SD-
APS) and St. Thomas for the Car-
ibbean Food Crops Society meet-
So, you see, the evalua-
tions are not all that bad! I appre-
ciate the time everyone takes out
to give me a chance to get out in
the field once in a while and see
some real diseases (in Salinas, CA
we used to call it "kicking a few
beets!"). It's really not enough,
but it will have to do. I'm con-
stantly amazed at the diversity of
our agriculture, soil types and dis-
eases in Florida and impressed
with the high quality and zeal of
our faculty and support staff. The
more I know of what you all are
doing, the better I can represent
our department.

Indoor Air Pollution
1 1, I: \ .. .. .. ..\

"Sick Building Syndrome"
is a condition we hear much about
today, applied both to our homes
and our workplaces. Environ-
mental specialists more clearly de-
fine this as not a sick building, but

conditions that cause many of its
occupants to become sick. It is
caused by indoor air pollution that
may be in the form of volatiles
which may, or may not, produce
odors but can cause allergic re-
sponsesmuch like smoking and
the accumulation of house dust
with allergens. One of the greatest
causes of indoor house pollution
has been the buildup of airborne
fungal spores. This is where the
Plant Pathology Department
comes into play, in particular the
Mycology Lab which deals with,
among other things, fungi in-
volved in indoor air pollution.
Some obvious signs of a
mold/mildew problem are the
appearance of surface molds on
walls and furniture, the staining
and puckering of wall covering,
and the grills of ductwork that
shows heavy contamination with
"house dust." Once stained or
puckered wall covering is pulled
away from the wall, a regular fun-
gal garden can often be found
with an array of different fungal
colonies. Scratchy throats, watery
eyes, rashes, bronchial wheezes,
breathing problems, and other
symptoms are common human
responses to fungal contamina-
tion. This is the problem that has
persisted in Fifield Hall for over
20 years, a problem that hopefully
is being corrected with the current
remediation work that is being
To fully understand
mold/mildew problems inside of
buildings, we must better under-
stand the fungi that cause them.
Members of the Kingdom Fungi
I\, [ .:..r i differ from other groups
of organisms in a number of ways,
of most importance they lack
chlorophyll (heterotrophic), have
walled cells without mouthparts,

and must therefore digest their
food outside the cells. Through an
elaborate enzyme system they are
able to digest nutrients and absorb
them from various substrates on
which they grow. Fungi reproduce
by spores that come in various
sizes, shapes, and colors. With
proper growth conditions, most
fungi will form millions of spores
per square centimeter of growth.
Most terrestrial fungi develop
windblown spores that can travel
considerable distances and be-
come ever-present in our atmos-
There are four basic things
that are essential for active fungal
growth: The presence of fungi,
suitable nutrients, proper tempera-
ture, and adequate moisture.
Presence ofFungi: Mycolo-
gists estimate that there are per-
haps more than 1,500,000 species
of fungi (Hawksworth 2001, Dic-
tionary of Fungi), although slightly
more than 82,000 were described
by this date and close to 1,000 new
species described annually. Over
90% of these species form wind-
borne spores. A single mushroom
or a molded orange, for example,
may release several million spores.
Spore production is seasonal and
populations of airborne spores
vary depending on the amount of
available substrate and moisture.
By pressing transparent
tape against a molded surface, it is
not unusual to find more than 3
million spores per square centime-
ter of surface. Studies on indoor
air quality in close to 180 homes
and more than 150 public build-
ings reveal that spore counts out-
side average close to 1200/ \ [' of
air, with peaks of close to 15,000
M3. Levels of spores in well-
maintained homes is close to
250/ \ [' of air, similar to that in

most public buildings. Poorly
maintained buildings may experi-
ence spore levels that more than
triple these numbers.
Nutrients: Molecular data
show that fungi have been around
for more than 460 million years;
they must have been doing some-
thing right. One of the things they
have done is to develop one of the
most elaborate enzyme systems
known. As a result, they are able
to invade all kinds of substrates,
although their preferences are
plants and plant products such as
sugars, starches, pectins, cellulose,
lignin, fats, oils, and complex hy-
drocarbons. As we look around
our homes and workplaces, we
find a great variety of substrates
on which fungi can grow. Many of
the textiles are of cotton, flax,
hemp, and many plant derived
materials. The major component
of wood is cellulose, and drywall
has a backing of cellulose with
organic adhesives. Soaps and other
household products have oils;
fungi love them. In recent years
we have learned that some of the
polyvinyls used in floor tiles are
susceptible to species ofAureo-
basidium, the fungi found years ago
to contaminate jet fuel tanks. Lent
and house dust are made up
largely of organic particles, nor-
mally including high numbers of
fungal spores. When house dust
accumulates in various cracks and
crevices, and the ductwork be-
comes heavily laden, spore loads
within the building will greatly ele-
During the 70s and 80s,
the construction industry began
using ductboard for the air condi-
tion ducts and HVAC boxes
within buildings. This material has
a fiberous inner lining, a lining
good for insulation but, unfortu-

nately, a lining that would trap
house dust that came through the
system. In a matter of 10-12 years
such duct lining becomes heavily
contaminated and during seasonal
changes especially, the material
would "flake" away and be blown
into the air we breathe. Allergy
patients will experience great dis-
comfort, may require increased
medication, and loose time from
work or school. The presence of
moldy odors is a sure sign of ac-
tive fungal growth.
Temperature: Most fungi are
mesophilic, i. e. they will grow best
at 750 to 950 F, but can grow from
500 to 1000 F. Most fungi enjoy
the temperature we enjoy and,
therefore, we can rule out the use
of extreme temperatures to con-
trol fungi. Temperature does play
a role during humid conditions
whenever it fluctuates and some-
times the dewpoint is reached, and
there is moisture condensation.
Moisture: The most vital
factor in fungal growth is mois-
ture. Why is this so? Fungi have an
adsorptive type of nutrition in
which water is largely necessary to
trigger enzyme production, trans-
port enzymes through the fungal
cell wall into the substrate, and
whenever enzymatic action basi-
cally dissolves nutrients in the sub-
strate, water is the carrier of nutri-
ents back into the fungal cells.
Most fungi grow best at a relative
humidity (RH) of 70% or above.
Most fungal growth will be elimi-
nated whenever the RH is kept
below 55%. Low RH delays spore
germination and greatly reduces
mycelial growth and sporulation.
Various substrates can adsorb sub-
stantial moisture from the air
when the RH is high. Florida
building codes require that drywall
moisture be held below 17% be-

fore it is installed. Warm air can
hold far more moisture than cool
air. Air at 800F can hold twice the
amount of moisture as air at 600F.
Thus, one of the keys to eliminat-
ing molds in the indoor environ-
ment is to maintain cool, dry con-

What Can Be Done?
There are a number of
things that can be done to control
moisture. During hot, humid sea-
sons, keep windows and doors
closed as much as possible, and
have good seals around the doors
and windows to prevent moisture
encroachment. Proper "sizing" of
air conditioners is vital. If the
HVAC unit is too small, the com-
pressor will run constantly, using a
great amount of energy, and yet
not cooling effectively. If an air
conditioner is "oversized" (too
large for the volume of air that
needs to be cooled) another prob-
lem occurs.
With a high cooling capac-
ity, the thermostat quickly tells the
unit "it's cool enough, stop."
When the compressor stops, de-
humidification stops, moisture
encroaches into the building and
condenses onto cool surfaces.
Once the thermostat calls for
more cooling, the unit does so
quickly and stops again. Research
in the Extension Engineering De-
partment of IFAS has shown that
when the air conditioner is shut
down in a building, within two
hours the conditions outside will
be the conditions inside. In poorly
insulated buildings, this could be
within an hour. Even though there
would be only a minute amount of
condensation between AC cycles,
over an 24/7 period, moisture lev-
els will reach the threshold for
fungal growth. Many public build-

ings have oversized air condition-
ers and usually results in "sweat-
ing" windows and the "clammy"
feeling of furniture and other
structures within.
Another problem in many
building is the use of vinyl wall
covering that will act as a vapor
barrier. It is almost impossible to
construct the "envelope" of a
building to withstand moisture
encroachment. Even the best of
building envelopes will soon lose
the effect as the building "settles"
and numerous cracks develop. If
moisture that penetrates into the
walls is allowed to get into the
rooms, the air will soon be dehu-
midified. If, however, there is vinyl
wall covering, the moist air will be
trapped behind the vinyl where
there is cellulose drywall backing
and adhesives that are excellent
nutrients for fungal spores trapped
there. How did the spores get
there? Did they encroach through
the wall like the moist air? Not
likely. Have you ever hung wallpa-
per? The large length of wallpaper
that you have dipped in water and
then position onto the wall...ever
so carefully to match the floral
pattern...is like a giant piece of
"fly paper." If there were 250
spores per cubic meter of air on
the day that wallpaper was hung,
several hundred of them likely ad-
hered to the sticky paper.
Mold growth on the outer
wall surface is an indication that
there is moisture condensing
within the room with ample nutri-
ents available for molds to germi-
nate and develop mycelium.

Common Fungi in the Indoor
During almost 20 years
of air sampling in homes and pub-
lic buildings, it is not unusual to

find at any one time dozens of
species representing 8 to 10 genera
of fungi. The genera below are
listed in order of their abundance.
Cladosporium: There are
a few hundred named species of
Cladosporum, many of them syno-
nyms. Today there are approxi-
mately 30 species recognized. Spe-
cies of Cladosporium make up about
60% of the airborne spore popula-
tion outside, 410"" inside, but
sometimes may represent close to
90% of indoor air. The colonies of
most species are grayish-green to
olive-brown in color. Four species
are very common in scrape sam-
ples from ductwork and house
dust. They are the most common
cause of mildew of textiles and
Penicillium: More than
300 species of Pc...:. have
been described. It is one of our
most cosmopolitan groups, grow-
ing on all sorts of substrates. They
cause decay of fruits, vegetables,
and other foodstuff, common on
various fabrics and building mate-
rials, and contaminate liquids that
have the least bit of nutrient. They
make up close to 310" ., of the spore
population within buildings. It is
important that species are identi-
fied correctly because certain spe-
cies cause mycoses in man re-
ferred to as penicilliosis. Many are
used industrially; noteworthy Peni-
.. notatum (=P. chbysogenum) that
is used in the manufacture of
Aspergillus: While spores
of Ai;-, ..' are found rather con-
sistently in air samples, they are
not as frequent as those of
Cladosporium and Pc...'. ,; Close
to 150 species have been de-
scribed, and like PR...:. '.', they
are found growing on all types of
substrates. Accurate identifications

are needed because a number of
species may cause aspergillosis in
man. A-. i a major problem
in the storage of grain because at
least three species, A.>.1 ,,, A.
parasiticus, and A. nomius have been
shown to produce "aflatoxins,"
the most carcinogenic compound
known. A number of species of
A, -c,.~. ,*, like A. niger, are used in
the commercial production of en-
zymes, organic acids, and many
other compounds.
Alternaria: Species ofAl-
temaria are found on living and
decaying plant material. Many
cause leaf spots and cankers in the
field; some get into the indoor
environment and find suitable nu-
trients on which to grow...if
moisture is adequate. More than
50 species have been described
and most represent common
cosmopolitan saprobes. They were
some of the first species to be
proven allergenic to man. They are
easily recognized by the brown,
obclavate spores with both vertical
and horizontal septa. "People traf-
fic" probably bring most of these
fungi indoors.
Curvularia: There 35
species of Curvlaria, which like
Altenaria, cause leaf spots of
plants and grow saprobically on a
wide variety of substrates. They
are able to grow and populate in
the indoor environment whenever
there is adequate nutrient and
Dreschlera, Bipolaris, and
Exerohilum, most recognized tradi-
tionally as Helminthosporum, like
Altenaria, are mostly plant para-
sitic or growing saprobically on
plant debris. Less often they are
found in the indoor environment,
probably the results of "people

Epicoccum: Only two spe-
cies of Epicoccum have been de-
scribed, the most common being
E. chartarum. They are weakly para-
sitic on plants but are found often
on decaying twigs and leaves. They
are fairly common in outdoor air
and are often picked up during
indoor air sampling. In culture,
they begin as a bronze colony that
becomes brown as the dark,
brown, globose spores appear.
Strikingly, they exude dark, purple
pigment into most media on
which they are grown.
Trichoderma: There are
close to 35 species of Trichoderma,
most of which are soil inhabiting.
They are found on all sorts of de-
caying plant debris outside and are
a widespread contaminant in-
doors. They are frequent on moist
building materials and on food-
stuff indoors. Certain species have
mycostatic properties and tend to
overrun other fungi that they grow
Others: There are several
other genera of fungi which are
isolated less often in the indoor
environment. They include: Acre-
monium, Aureobasidium, Botytis,
Fusarium, Mucor, Paecilomyces,
RhiZopus, Sporobolomyces, Scopu-
lariopsis, and Stachybotys.
Stachybot/ys is noteworthy
because if drywall, suspended ceil-
inmo tile cArrlhnArl hnvei hrrnnlk

and other cellulosic material be-
Stachybotis sp. (Courtesty of Botany De-
partment, University of Toronto)

come wet and remain moist for a
few days, species of a deep black
mold, Stachybotgys chartarum will
appear. This species causes
"stachybotryosis" in horses and
"pulmonary hemosiderosis" in

young children who breathe vola-
tiles that may be produced by ac-
tive growth of this mold in homes
with heavy contamination of cellu-
losic materials after flooding or
water leaks.

Dr. Tom Kucharek Receives Outstanding Plant Pathologist Award in Tulsa

Dr. Thomas Kucharek,
professor in the Department of
Plant Pathology at the University
of Florida since 1970, was recog-
nized by the Southern Division of
the American Phytopathological
Society with the Outstanding Plant
Pathologist Award, at the SDAPS
Meeting in Tulsa, Oklahoma. Dr.
Kucharek has been responsible for
extension and research programs
involving both agronomic and
vegetable crops in Florida.
Making valuable contribu-
tions to disease control for grow-
ers across Florida, Dr. Kucharek
has been credited with numerous
discoveries and developments
such as: the determination that
Exerohilum rostratum causes stalk
rot of corn, developing a profit-
able fungicidal spray program for
wheat using aircraft, discovering
soilbome wheat mosaic virus in
Florida and identifying resistant
cultivars, producing the first inte-
grated disease control programs,
and determining that soybean seed
treatments with chloroneb re-
duced Rhizoctonia blight increas-
ing yields.
Dr. Kucharek also associ-
ated blue mold with rain events
and overhead irrigation, and dem-
onstrated that metalaxyl sup-
presses blue mold and black shank
in tobacco. Dr. Kucharek also
researched Actigard and was the
first to determine suppression of
blue mold of tobacco and the vi-
rus causing tomato spotted wilt

with this product. Predicting
models for peanut yield based on
disease progress curves of peanut
leaf spot and demonstrating the
importance of crop rotation in
managing the disease, Dr. Ku-
charek's system was used by IPM
scouts across the southeast for
many years. Despite all of his ac-
complishments, Dr. Kucharek is
quick to include his student's con-
tributions in identifying fungal
communities in roots, pods, and
pegs of peanut and the demonstra-
tion that late leaf spot resistance is
due to reduced and delayed sporu-
lation by the causal fungus.
By reducing the spray
pressure, which reduced drift, Dr.
Kucharek suggested that more
effective peanut leaf spot control
could be obtained more economi-
cally by requiring fewer tank refills
for growers. Recently, Dr. Ku-
charek demonstrated that coat-
protein mediated transgenic resis-
tance squash cultivars and those
with Mendalian resistance to vi-
ruses are important sources for
spring plantings, however, they are

susceptible to papaya ring spot
virus type W in the fall. Dr. Ku-
charek has published his research
findings extensively throughout
refererred journals and meetings,
authoring many extension fact
sheets, plant protection pointers,
manuals and farm magazine arti-
cles since the 1970's.
Furthermore, Dr. Ku-
charek was instrumental in the
development of the University of
Florida Plant Disease Clinic,
where he incorporated new tech-
niques in disease diagnostics such
as: selective media for Pythium and
Phytophthora ssp. Isolation, exami-
nations of viral cellular inclusions,
and tobacco hypersensitivity as-
says to identify bacterial infections.
Including the SPAPS Outstanding
Plant Pathologist Award, Dr. Ku-
charek has been recognized by
numerous organizations for his
extension and research contribu-
tions. The Florida Association
County Agricultural Agent's Out-
standing Specialist Award, Ameri-
can Horticultural Society Exten-
sion Publication Award, and Uni-
versity of Florida Professional Ex-
cellence Award are just a few of
the various awards bestowed upon
Dr. Kucharek. Furthermore, Dr.
Kucharek is active in the APS,
serving as President and Secretary,
in the past, and on various com-
mittees. Congratulations Dr. Ku-


An international project
on the risks of importation of cit-
rus black spot, an exotic disease
caused by Guignarda itricarpa, is
being conducted through CREC,
Lake Alfred and is being funded
by the California Citrus Research
Board. Most of the research is
being carried out in Brazil and Ar-
gentina. The project involves de-
velopment of methods of detec-
tion of G. dtricarpa and differentia-
tion of the pathogen from the
widespread saprophyte, G. mangf-
erae. Fungicide spray programs,
postharvest treatments, and cold
storage are being evaluated to re-
duce or eliminate postharvest de-
velopment of symptoms.
Survival of the fungus in
decaying fruit and foliage is being
determined. Pete Timmer, Pro-
fessor of Plant Path at CREC, is
the project coordinator. Natalia
Peres manages the work on mo-
lecular methods of detection of
the pathogen and other aspects of
the Brazil portion of the project.
She was formerly located at the
Institute Biologico in Sao Paulo,
but has since relocated and is now
Assistant Professor of Plant Pa-
thology at GCREC in Dover.
Juan Pedro Agostini,
Research Plant Pathologist with
INTA in Montecarlo, Misiones,
Argentina, conducts most of the
work on survival and preventing
postharvest appearance of the dis-
ease. Juan Pedro received his M.S.
and Ph.D. in the department un-
der Pete's supervision (we won't
mention how many years ago).
Jim Adaskaveg, Associate Pro-
fessor of Plant Pathology at the
Univ. Calif., Riverside, conducts
some work on the molecular as-
pects and helps coordinate the



A: hard spot and B:
virulent spot, two
symptoms of black
spot (P. Timmer).

In the spring, graduate
students from the Dept. of Plant
Pathology PLP 6905 course, vis-
ited the CREC on Feb. 6, 2004.
The students visited CREC's plant
pathology faculty, toured the Cen-
ter and examined citrus diseases.

JILl O(VUs visiting group v
gartner and Timmer.

In February, Pete Timmer,
Holly Chamberlain, Natalia Peres,
Sachindra Mondal, Mukaddes
Kayim and nearly 30 University of
Florida/IFAS scientists partici-
pated in the International Society
of Citriculture (ISC) Xth Congress
(February 15-20) in Agadir, Mo-
rocco. The meeting included oral
and poster presentations, sympo-
sia and optional tours to citrus
operations, research facilities and
cultural sites in Morocco. Below
is a list of oral and poster presen-
tations from Plant Pathology per-

Regeneration of Trans-
genic Sweet Orange Plants Con-
taining a 742bp Citrus Tristeza
Virus-Derived Sequence 392
Ananthakrishnan, G., Gowda, S.,
Orbovic, V., Dawson, W.O. and
Grosser, J.W.
Ascospore Development,
Maturation, Discharge and Infec-
tion of Citrus by 3 I5~. .*. 'ti,
the Cause of Citrus Greasy Spot -
Mondal. S.N. and Timmer, L.W.
Distribution and Control
of Altemaria Brown Spot on Tan-
gerines and Their Hybrids in Bra-
zil Peres. N.A.R. and Timmer,
Screening Selected Citrus
Germplasm for Resistance to
Witch's Broom Disease of Lime
(WBDL) Khan. I.A., Lee, R.F.,
Grosser, J.W. and Hartung.
Molecular Characteriza-
tion of Disease Resistance in Cit-
rus Febres, V., Carlos, E., Der-
rick, K. and Moore. G.A.
Expression of Mutant
Green Fluorescent Protein Genes
in Transgenic Citrus Plants -
Kayim. M., Derrick, K. S., Barthe,
G.A. and Beretta, J.M.
RNA Profiling on Trees
Affected by Citrus Blight Carlos
E.F., Beretta, M.J.G., Barthe, G.,
Denslow, N., Larkin, P., Derrick,
K.S., and Moore, G.A.
University of Florida Cit-
rus Canker Extension Program -
Chamberlain. H.L., Timmer,
and Zekri, M.


A lab technician's visit to
the UF/IFAS Citrus Research and
Education Center in Lake Alfred
may help slow or prevent the de-
cline of the citrus industry on the
small Caribbean island of Domin-
Naomi Commodore, a
lab technician for the plant protec-
tion and quarantine services of the

Dominica Ministry of Agriculture,
visited CREC May 11-13, to learn

techniques to detect citrus tristeza
virus. The virus, transmitted by
the brown citrus aphid, has caused
nearly a total loss of trees from
sour orange root stock in the
southern part of Dominica, Com-
modore said.
Commodore traveled to
Florida as a follow-up to a March
14-25 trip to Dominica taken by
UF/IFAS professor Ron
Brlansky, as part of a cooperative
effort between UF/IFAS and
Dominica scientists to detect mi-
grating citrus diseases and to pre-
pare defenses against them.
While in Dominica,
Brlansky, a Plant Pathologist, ex-
amined strains of citrus tristeza
virus present in the Caribbean.
Commodore visited CREC to re-
ceive training in virus detection
techniques from Brlansky to de-
termine the spread of citrus
tristeza virus over the island.
Brlansky taught Commo-
dore the tissue blot and the en-
zyme-linked immunosorbent assay
(ELISA) techniques for detection.

"We are hoping to control
the host trees infected with the
virus," said Commodore, who has
been working on the project for
about a year. "Identifying trees
already infected will decrease the
spread of the aphid."
After identifying and
eliminating trees infected with the
citrus tristeza virus, Dominica will
begin the use of a new citrus root
stock immune to the virus. Do-
minica currently uses sour orange
root stock which is most suscepti-
ble to citrus tristeza virus.
"The virus is new to us
and no one on the island has train-
ing to combat it," Commodore
said. "Now I have learned tech-
niques to go back and do surveys,
so we can eliminate the virus."

A paper published by CREC scientists W. Li, R. Yuan, J.K. Bums, L.W. Timmer and K.R. Chung was se-
lected as the American Society for Horticultural Science Outstanding Cross Commodity Publication for 2004. The pa-
per, "Genes for hormone biosynthesis and regulation are highly expressed in cit-
rus flowers infected with the fungus Colletotrichum acutatum, causal agent of post-
bloom fruit drop," was published in the Journal of the American Society for Hor-
ticultural Science JASHS 128:578-583, 2003), and was selected from all papers
published in JASHS, HortScience and HortTechnology in 2003. The authors will
Sbe honored at an awards ceremony at the ASHS Annual Meeting on July 17 in
Austin, Texas. In addition, an enlarged version of the paper will displayed with
S other Outstanding Publications at the meeting. The research is funded in part by
a grant from the Florida Citrus Production Research Advisory Council (Florida
citrus growers).

Dr. Chung, the lead investigator on the study, joined the CREC faculty in Lake
Alfred as Assistant Professor of Plant Pathology in 2000. His current research
program focuses on fungal genes involved in the development of postbloom fruit drop in citrus. A native of Taiwan,
Dr. Chung received his B.S. and M.S. degrees in Plant Pathology from the National Chung-Hsing University in Taiwan.
He received his Ph.D. in Plant Pathology 1996 from the University of Kentucky, and also worked as a postdoctoral sci-

entist with Dr. Margaret Daub at North Carolina State University, where he studied the molecular regulation of toxin
resistance and toxin production by the fungus, Cercospora.
Kate A. Lahey and Huiqin Chen from Dr. K.R. Chung's laboratory at CREC-Lake Alfred gave an oral presen-
tation, "Molecular interactions between citrus and Colletotrichum acutatum" at CREC's weekly "Plant Path and Friends"
seminar on April 2. The fungus, Colletotrichum acutatum, is the causal agent of postbloom fruit drop. Dr. Chung is also
coordinator of the "Plant Path and Friends" seminar series

Following One of Our Own: From the Magic Kingdom to Outer Space

Dr. Andrew C. Schuer-
ger received his BS (1979) and MS
(1981) degrees from the University
of Arizona and his Ph.D. (1991)
from the University of Florida
studying microbiology and plant
pathology. His dissertation stud-
ied the effects of temperature and
pH on spore attachment of the
fungal pathogen, Fusarium solani f
sp. phaseot, to roots of mung bean
plants grown in hydroponic sys-
tems. Dr. Schuerger worked for
16 years at The Land (a hydro-
ponic research and education facil-
ity) at Epcot Center, FL develop-
ing disease management programs
for viral, bacterial, fungal, and
nematode diseases of vegetable
and agronomic crops. His re-
search interests have closely paral-
leled NASA's Advanced Life Sup-
port (ALS) and Astrobiology pro-
grams in which he has published
articles on plant-pathogen interac-
tions in semi-closed plant growing
systems, survival of terrestrial mi-
croorganisms under Martian con-
ditions, and microbial ecology of
human explorations of Mars. In
1997, Dr. Schuerger joined the

Dynamac Corporation (a NASA
contractor at the Kennedy Space
Center, FL specializing in envi-
ronmental and life sciences) to
pursue research on the remote
sensing of plant stress, Mars astro-
biology, and ALS plant pathology
issues. In 2003, Dr. Schuerger
joined the Dept. of Plant Pathol-
ogy at the University of Florida as
a Research Assistant Professor to
continue his Mars astrobiology
and ALS research activities. His
office and lab are located in the
newly constructed Space Life Sci-
ences Lab at the Kennedy Space
Center, FL.


The photo shows Dr. Schuerger setting
up experiments in a large 1.2 m3 Mars
simulation chamber at the Kennedy
Space Center, FL.

One component of his
current research program has been
funded by NASA's Office of
Planetary Protection. These ex-
periments have been designed to
study the effects of martian condi-
tions on the survival of dormant
spores of common terrestrial bac-
teria typically found as spacecraft
contaminants. Results were re-
cently published in the interna-
tional journal, Icarus (2003,
165:253-276), and indicate that
most terrestrial bacteria on sun-
exposed surfaces of spacecraft will
be rapidly inactivated on Mars.
Dr. Schuerger has more
recently been investigating the is-
sue of microbial growth and repli-
cation under martian conditions.
Preliminary results suggest that
many (and perhaps most) terres-
trial microorganisms may not be
capable of growth and replication
under martian conditions due to
the extremely harsh conditions on
Mars of low pressure, high desic-
cation, and low nutrient status of
the regolith.

Student Accomplishments: Awards and Graduations

Lisa Nodsen recently gave a presentation to PMCB faculty members at a retreat, which earned her the distinc-
tion of "Honorable Mention". Lisa was one of only three student speakers recognized from a field of sixteen, by PMCB
faculty members.
Jennifer Cook won the Outstanding Weed Science Student award from the Florida Weed Science Society and
shared the society's Scholarship award. Both carried cash prizes and in addition the "Outstanding" award carried a
plaque. Both were awarded to Jennifer at the annual meeting of the society at Ft. Pierce on February 24, 2004.

Graduate students from the Plant Pathology Department were inducted into The Honor Society of Agriculture,
Gamma Sigma Delta. Past President, Joe W. Kotrlik, once stated "Gamma Sigma Delta makes a substantial contribu-
tion to the cohesiveness of our students, faculty, and staff in all fields in the agricultural family. The recognition of
scholarly research, quality teaching, professional service, and student/faculty performance is highly valued by everyone
on campus." So, congratulations go out to Matt Brecht, Jennifer Cook, Whitney Elmore, Andy Hutchins and Fab-
ricio Rodrigues, on their invitation to join and recent induction.

Congratulations PLP Folks!!!!

Plant Pathology graduate
students obtained their respective
degrees during a ceremony cele-
brated on April 30, 2004. These
students are:

Dr. Ronald French, Dr. Jane Luzar,
IFAS Associate Dean and Professor.,
and Abby Guerra.
Abby Guerra (MS de-
gree), working on characteriza-
tion of Citrus leprosis virus with Dr.
Richard F. Lee; Ronald French
(PhD), working on ecological
and phylogenetic characterization
of Phytophthora capsic in Florida
with Pamela Roberts and Jeffrey
Jones; Fabricio Rodrigues
(PhD), working on the mecha-
nisms of silicon-mediated rice
blast resistance with Drs. Law-
rence E. Datnoff and Jeffrey B.
Jones; and Curt Colburn (PhD),
working on Phytophthora root rot
of cit-

Dr. Jim


Ren Chung.

Annual PLP Graduate
Student Association
Mushroom Sale 2004
. I ( ,, .. .

This year the PLP
Graduate Student Association
mushroom sale took place at the
end of ADril 2004. As usual.

-..** .. *

the event was a success. The
mushrooms (white and Porto-
bello) were donated by Monterey
Mushrooms Company. People
from everywhere in Gainesville
came to buy the delicious mush-
rooms. Thanks to the graduate
students, professors, and every-
body who helped to make the
activity possible.
All the profits support
the PLP Graduate Student Asso-
ciation. See you next year, so get
your order ready!

PLP graduate students can make the
grade and the sale!

PLP in Cuba!

Recently, folks from our
department attended the APS
Caribbean division Annual Meet-
ing celebrated in La Havana,
CUBA from May 24 28, 2004.
Dr. Ronald Brlansky (CREC)
and Deborah Howd (CREC)
offered a pre-meeting workshop
on identification of citrus dis-
eases by using transmission elec-
tron microscopy and Dr. Man-
junath Keremane offered a
workshop on detection of RNA
viruses by using molecular tech-
niques from April 20 23, 2004.
Dr. Ronald French (Gainesville),
Dr. Pam Roberts (Immokalee),
Dr. Mike Davis (Homestead),
Dr. Siddrame Gowda (CREC)
and Dr. Rama Urs (Immokalee),
also attended the meeting in

Drs. Manjunath Keremane and Ron
Brlansky with their group of students at
the workshops.

New PLP Faces

New to the PLP com-
munity at the University of Flor-
ida is Aaron Palmateer.

Aaron is the new Plant Patholo-
gist at the Plant Disease Clinic in
Homestead. Dr. Ken Pemezny
has two new biological scientists in
the lab, Nikol Havranek, and
Jairo Sanchez.
Nikol is from the Czech
Republic and has been in the US
for 5 years. She came to us from
the University of Maryland. Jairo
is originally from Columbia. He


received an associate degree in
agriculture from a university in
Canada, and is currently classified
as a senior laboratory technician.
Dr. Amer Fayad is a
postdoctoral scientist at the Citrus
Research and Education Center,
working with Dr. Ronald
Brlansky. Dr. Fayad, who is from
Lebanon, holds a B.S. and M.S.
degree from American University
in Beirut. He completed a Ph.D.
in Plant Pathology from Virginia
Tech University in December,
where he conducted research on
soybean mosaic virus with Dr. Sue
Tolin. His research included stud-
ies on the molecular diversity be-
tween isolates of soybean mosaic
virus, and yield effects of resis-
tance breaking strains. Dr. Fayad
came to CREC in February 2004.
Ayna Salas completed a
two-month student internship
with Dr. Ronald Brlansky at the
5 .

Citrus Research in Education Cen-
ter in May.
A native of Ecuador, Ayna
is a senior Agronomy major at
Zamarano University in Hondu-
ras, where only top students are
selected for foreign internships.
While at CREC, she learned mo-
lecular biology and electron mi-
croscopy techniques, and she en-
joyed her stay at CREC so much
she says she would like to return
to pursue graduate studies.


With a new year came new
retirements in the Plant Pathology
Department. Newly retired PLP
faculty and staff include: Dr.
James Kimbrough, Dr. Ernest
Hiebert, Dr. "Pete" Weingartner,
Dr. Dave Mitchell, and Mr. Lus-
cious Mitchell. The department is
lucky to have most of these great
folks hanging around to help out
part-time for the next few years.
Wh! Ir -..11i.1 we do without them?!

Dr. Hiebert, his wife, Luscious Mitchell,
his wife, Dr. James Kimbrough, his wife,
and Dr. Gail Wisler.

Dr. "Pete"
Gail Wisler.

Party Time!

With graduations in the
spring and birthday parties every
month, the PLP graduate students
know how to unwind. Occasion-
ally, the students et to ether for
ne, A

~I -~*c I I

~1'i OHIE

and a lot of fun. The PLP stu-
dents at The University of Florida
are diverse in nationality as well as
culture, but we all have one thing
in common, the need to have a
good time! Here are some exam-
ples. Some of the "guys" pose at
Abby's birthday party.

Above, Fabncio, Manon, and Ronald
celebrate at a graduation party.

Team Up to Prepare
for Soybean Rust

( ," I .' .1' I'"
'. .. ( ...., ,.. .. '/ ",

On May 11th, 2004, over
40 people from the southern re-
gion gathered in Raleigh, NC, to
attend a Soybean Rust Response
workshop. Eleven states in the
southern region, plus representa-
tives from the North-Central and
Northeast regions, participated in
a two-day workshop aimed at de-
veloping state-specific response
plans, should soybean rust be
found in their state. The work-
shop was jointly hosted by the
Southern Plant Diagnostic Net-
work (SPDN) and the Southern
Region IPM Center (SRIPMC).

Participants were invited
to ensure representation from
each state in the areas of exten-
sion, plant pathology departments,
IPM, agricultural regulation, and
the SPDN.
Experts elucidated the
issues involved in efforts to detect,
diagnose, and deal with soybean
rust. The participants then used
the information in discussions
concerning aspects of response in
thoir annrn Clttl-c

A round-table discussion
of Iowa's draft plan helped focus
the attendees on the issues they
may need to prepare for. This
process has been carried back to
their states and those representa-
tives will bring together the ex-
perts in their locality who will then
help them work out the details of
a state-based response plan for
soybean rust.


ror more inrormanon, please visit
http://spdn.ifas.ufl.edu/spdn me
etings.html (Photos courtesy ofj.
Hodorowitz, SRIPMC)

Safety: On the road, in
the lab

At some point, everyone
has an accident "on the job."
Whether in the lab, in the field, or
in a state vehicle, it is everyone's
responsibility to become informed

about UF policies and procedures
in the event of an accident or mis-
hap. Unfortunately, when some
of us are at work/school, we tend
to hurry about to get the job done
on time. But, don't let this impor-
tant, but often overlooked tidbit
pass you by.
Thanks to Ulla Benny,
some much needed information
concerning safety belt use has
come to light. Based on a long-
standing UF policy, all university
employees and students are re-
quired to wear seat belts while rid-
ing in or driving a state vehicle
(this is also a state law).
Apparently, disciplinary
action, ranging up to termination,

may be taken if this policy is ig-
nored. Additionally, worker's
compensation benefits will be re

duced by 25% in the event of an
injury caused by an accident, in
which the occupant was not buck-

led up. So buckle up PLP Mem-
bers! It's the law!

Contacts and Subission

If you would like to contribute an article, a short piece, or a suggestion, please send correspondence to:

PLP News
1453 Fifield Hall P.O. Box 110680, Gainesville, FL 32611

News Team and Collaborators for spring, summer, and fall 2004:

Whitney Colleen Elmore

Dr. Gail Wisler, Dr. Pete Weingartner, Dr. Pete Timmer, Dr. Fabricio Rodrigues, Dr. Ken Perezny, Dr. Andrew
Schuerger, Dr. Charudattan, Dr. Wenyuan Song, Carrie Harmon, Dr. Ron Brlansky, Dr. James Kimbrough, Ulla Benny,
Monica Lewandowski, Jean Morton, Abby Guerra, and Adriana Castafieda.

PLP News is available online at: http://plantpath.ifas.ufl.edu/

The opinions expressed in this newsletter are not necessarily those of the PLPNews Staff

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