The Mission of UF/IFAS is to develop
knowledge in agricultural, human and
natural resources and to make that
knowledge accessible to sustain and
enhance the quality of human life.
Spring 2008 UF
April, May & June
Lake County Extension
Spring is a wonderful time of year, with the smell of orange blossoms filling the air. Early and Mid harvesting
has wrapped up and Valencias are starting. Since the last newsletter citrus greening has been found in com-
mercial groves in Lake County. The growers who are finding the disease are the one's who are surveying for
greening. In addition, citrus canker has been showing up more recently around the Central Florida area. Early
detection of canker is beneficial for management decisions to help slow the spread of the disease. If you have
not started to survey your grove I encourage you to begin the planning process, so that you can start this sum-
mer. Equally important is to have a spray program to control psyllid population levels. As always if you have
any questions concerning these topics please feel free to contact me.
COOPERATIVE EXTENSION SERVICE, UNIVERSITY OF FLORIDA, INSTITUTE OF FOOD AND AGRICULTURAL SCIENCES, Larry R.
Arrington, Director, in cooperation with the United States Department of Agriculture, publishes this information to further the purpose of the May 8
and June 30, 1914 Acts of Congress; and is authorized to provide research, educational information, and other services only to individuals and insti-
tutions that function with non-discrimination with respect to race, creed, color, religion, age, disability, sex, sexual orientation, marital status, na-
tional origin, political opinions, or affiliations. Single copies of extension publications (excluding 4-H and youth publications) are available free to
Florida residents from county extension offices. Information about alternate formats is available from IFAS Communication Services, University of
Florida, PO Box 110810, Gainesville, FL 32611-0810.
Are there psyllids living in "abandon groves" and in pine forests
with understory citrus trees?
I have had few conversation with growers and research-
ers about abandoned groves and citrus trees that are
growing under planted pines. Everyone would share
their idea of what was happening in these situations.
Some would say of course they're a source of psyllids,
others would say that most of those trees do not have
flush, thus they do not have psyllids, neither were a
100% sure. I had planned to start observing these two
situations; abandoned groves and understory trees. I
picked a couple of locations that were conveniently lo-
cated on my path from home to work. I had acquired
some psyllid traps from Dr. Stelinski (Thanks Lukasz!) and set off into the "woods" to hang them. Right away
I noticed understory trees had new flush. I was somewhat surprised as it was early February and I was not ob-
serving any commercial groves flushing (ok maybe some young navel trees with flush). After scouting for
psyllids for all of two minutes I had found three adults. I then headed to an abandoned grove. There flush was
more difficult to find, although I did manage to find some and on it was an adult psyllid (presumably feed-
ing?). I had in a matter of an hour answered in my own mind with a 100% certainty that yes psyllids are pre-
sent in abandoned groves and planted pines. Do they stay there all year? What is the population level like?
Don't know the answers to these questions but I will continue to monitor to find out.
Pherocon AM No-Bait Traps are used to moni-
tor psyllid population levels. They can be a
tool to help you make decisions concerning
your psyllid control spray program. Make sure
to purchase the No-Bait traps as the baited
traps with be full of flies after a 24 hour pe-
riod. The traps cost around a dollar and can be
purchased from either:
Trece Inc. Phone: (866) 785-1313 or
Great Lakes IPM: (800) 235-0285
J age 3
A Summary of the paper: Comparison of visual assessment and
PCR assay testing to estimate the incidence of the LB5 pathogen
in commercial Florida citrus.
Michael S Irey, Tim Gast and Tim R. Gottwald Proc. Fla. State Hort. Soc. 119:89-93. 2006
Dr. Bill Castle made the recommendation that I review a paper from the FSHS meeting as an article for my
newsletter. I thought it was a good idea and it has only taken me a year to implement it! In honor of FSHS
meeting coming up in June I would like to summarize the paper that won the "best paper" award in the citrus
section from the 2006 meeting.
An experiment was conducted to compare the results between visual and real time Polymerase Chain Reaction
(PCR) confirmation of greening. PCR is a type of DNA test that is conducted to determine if the greening bac-
teria is present in plant tissue. The location of the experiment was in naturally infected blocks in S. Florida.
Five 14 row by 14 tree blocks were used in the experiment. The visual surveying was done by trained scouts
who walked the rows to visually inspect 4 year old Valencia on Swingle trees. Any samples taken by scouts
were confirmed or denied by a supervisor. Trees identified with greening were flagged. The same trees were
sampled for PCR analysis. If visual symptoms were present, one or two symptomatic leaves were collected
while the rest (up to 4 per tree) were collected arbitrarily. Trees that did not have greening symptoms had four
leaves sampled from 3 of the 4 sides of the tree.
When adding up the results from the five blocks that were sampled the mean of visual negative versus PCR
negative were the same 89.4% of the trees in the blocks. The mean of the visual positive versus PCR positive
were the same 5.5% of the trees. Over the five blocks visual assessment and PCR results agreed 94.9% of the
time. What does this mean? The visual assessment by the scouting team was very accurate in picking out
Table 2. Percentage of anlipl.-s that Ml inl,, the four possible combined test result categories. From FSHS Proc. 119: 2006 pg. 91
Possible test results C3: trees 20-33 C3: trees 71-84 C4: trees 11-24 C4: Irfes 61-74 C4: trees 81-94 Mean
Vsla I Iai ei/real-time PCR negative 74.6% 96.8% 98.0% 82. I' 95 F4" 89.4%
Visual ii /', iiki /real-time PCR positive 11.6% 1.1% 1.0% 4.6% 2 I1 4.1%
Visual posili e /real-time PCR positive 11.6% 1.6% 1.0% 11.2% 2 1. 5 i,..
Visual positive/real-time PCR negative 2.1".. 0.5% 0.0% 2.1'.".. 0.5% 1.0%
positive or negative greening trees. Another outcome of this study showed the ability of real-time PCR testing
to detect asymptomatic greening infections in grove trees, due to this fact the authors suggest that PCR might
be successful applied to the testing of budwood sources. They also conclude that improvements to PCR can be
made when more is learned about the bacteria and its relationship to time of year, location within a tree and
The investigators also looked at spatial analysis to determine what would be an ideal sized area for tree re-
moval in order to remove infected trees that were not showing visual symptoms. This is similar to what was
done to determine the 1900' rule for canker. They concluded that more detailed studies were necessary to de-
termine optimum rouging strategies.
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Fig. 2. Results of visual and real-time PCR assessments in five 14 row by 14 tree grids. Row/tree combinations highlighted in yellow were positive by real-
time PCR only, combinations highlighted in gray were positive by both real-time PCR and visual assessments, and combinations highlighted in orange were
positive only in the visual assessments (P = real-time PCR results. V = visual observations. X = missing trees).
OJ Meeting- Citrus Canker update
May 6th 6PM-8PM
Please plan on joining us for our second night
time OJ meeting on May 6th from 6 PM to 8 PM.
The program will be an overview of citrus can-
ker and management considerations. We will
again be having a free dinner which is spon-
sored by Nichino America Inc. and Sunniland
Corp. Please call Maggie by May 1st to regis-
ter at 352-343-4101. It is important that you let
us know if you are going to attend so that we
know how much food to order!
Overview of Canker/Canker control
7:20-7:40 Pheromones for Leafminer Control
-Dr. Lukasz Stelinski
7:40-8:00 Citrus Windbreaks
-Dr. Bill Castle
Avon Park 9:00-4:30
The extension service is hosting a greening
summit. The summit will be held in Avon Park
at the South Florida Community College main
campus. The topics will cover current status of
greening, research projects, control pro-
grams, survey techniques, Brazilian experi-
ences, and a grower panel. The agenda and
registration form has previously been mailed
and can be found at:
If you would like to attend please register
ASAP to Jane Wilson at 863-956-1151 or
mjw(crec.ifas.ufl.edu as space is limited.
Private Agricultural License Review &
Exam May 20th 8:30-4:00
A pesticide license is required by any persons
who apply or supervise the application of re-
stricted use pesticides for agricultural produc-
tion. This certification requires a passing
grade of 70% on the General Standards and
Private exam. This certification must be re-
newed ever 4 years either by testing or by 8
There will be a review and exam in Kissimmee
on May 20th. The review starts at 8:30 AM.
There is a $20 charge for the class.
It is advisable to purchase the "Applying pesti-
cides correctly" and "The Private Applicator
Pest Control Training Manual" from the IFAS
bookstore on-line at www.ifasbooks.ufl.edu or
by calling 800-226-1764.
The private agricultural license itself cost $60
which does not have to be paid until after you
pass the exam. To register please call Osceola
County Extension at 321-697-3000.
Florida State Horticultural Society
Meeting Ft. Lauderdale June 1-3rd
I highly recommend growers attending the
Florida State Horticultural Society annual meet-
ing. This years keynote speaker is Florida's
Agriculture Commissioner Charles Bronson.
The meeting is full of good research informa-
tion. To promote this event I have included a
review of one of the papers that was presented
at the 2006 event. It happened to win the best
paper award for the Citrus Section. Not only
do you get to learn a thing or two; there is also
great fellowship to be had! For more informa-
tion please take a look at the website.
Greening Pictures Lake Co.
This pictures came from a navel tree
located off highway 19 in Lake County.
These pictures were taken in mid-
January. The three pictures are from
the same tree that has been PCR con-
firmed infected with greemng. In the
upper right hand corner you can see
the bright yellow area that caught the
survey crew members eye. In the up-
per left hand corner is a close up of
the section. Leaves in this area were
yellow veined and were falling off, as
is apparent by the sparse foliage in
the picture. In the lower right hand
corner is an even closer view. There
you can see that there are some flow-
ers and leggy limbs which all the
leaves have fallen off of.
Greening Pictures Lake Co.
This pictures are from a Lake County Valencia grove
located near Cleimont Sii r\e\ cie\\s noticed that the
top of the tiees \\ee sparse. that is lacking lea\ es isee
the Io\\er left iNcture) Uipon further in\ estig ation
smaIll. Lopsided fruit \\ere present \\When \ouI cut the
fruit in half aborted seeds \\ ere found \\When looking
closely\ at the lea\ es the\ had some sins of blotch\
model The picture to the Ullt slo\\ s some of the
si mptoms that \\ ee present The pictLie abo\ e so\\ s
off season bloom (this \\"as taken in eaIl\ December)
N\ %, 4.&
Ve I.*'* `
SWFREC opens additional New
Greening Testing Facility
The University of Florida's Southwest Re-
search and Education facility has begun real-
time PCR testing for grower greening sam-
ples. This new facility will help with the in-
creasing number of samples that are being
submitted to the Clewiston facility. Rules for
submitting samples are similar to the Clewis-
ton facility and can be found at http://
swfrec.ifas.ufl.edu/hlb/ or contact them at
Nutrition of Florida Citrus
Trees 2nd Edition available
The Nutrition of Florida Citrus Trees 2nd edi-
tion has been released. Drs. Tom Obreza
and Kelly Morgan have edited the manual
that was originally written 13 years ago. The
new version has the latest nutritional BMP
and fertilizer recommendations for citrus.
This booklet is 96 pages and includes many
colored photos. If you would like a copy of
the nutrient publication please feel free to
contact the Lake County Extension office.
The 2008 Florida Citrus Pesticide Management Book
is available. http://www.crec.ifas.ufl.edu/extension/pest/
Table 1. List of insecticides and miticides recommended for use in the Florida Citrus Pest Management Guide and their effects on different
pests and beneficial insects (Revised January 2008).
Pesticide active Target pest Effects on
ingredient Mode of Psyllid Leafminer Rust Mites Spider Root Weevil Scale Insects Mealybugs beneficial
Action' Mites Adults insects
Abamectin +oil 6 ++ +++,R +++,R + + (oil) +(oil) + (loll medium
Acetamiprid 4 +++,R _- ? + ++ medium
Aldicarb 1A +++,R +++,R +++ __low
Carbaryl 1A +++,R -+ ? +++,R +++,R + high
Chlorpyrifos 1B +++,R + + + +++,R +++,R high
Diflubenzuron 15 ++ +++,R +++,R +++,R -low
Dimethoate 1B +++ -- ? +++,R + high
Fenbutatin oxide 12 +++,R +++,R low
Fenpropathrin 3 +++,R ? + + +++,R + high
Imidacloprid 4 +++,R +++,R + ++ + low
(soil appl., nonbearing)
Imidacloprid 4 +++,R + ++ + medium
Petroleum oil NR + ++,R ++,R ++ +(eggs) ++,R + low
Pyridaben 21 ? ++ +++,R high
Spinosad 5 +++,R -- Low
Spinetoram ? +++,R ? ? ? ? ? Low
Spirodiclofen 23 +++,R +++,R ? low
Sulfur NR +++,R +++ ? ? High
'Mode of action class for citrus pesticides from the Insecticide Resistance Action Committee; NR = no
(R) = product recommended for control of pest in Florida Citrus Pest Management Guide
(+++) = good control of pest
(++) = short-term control of pest UNIVERSITY of
(+)= low levels of pest suppression FLORIDA
(-)= no observed control of pest
(?)= insufficient data available IFAS Extension
Lake County Agricultural
1951 Woodlea Rd.
Tavares, FL 32778
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Sp ,in 2008 The Vision for the University of Florida's Institute of Food and Agricultural
Sciences (UF/IFAS) is to increase and strengthen the knowledge base and tech-
Center Expanding the profitability of global competitiveness and sustainability of
the food, fiber, and agricultural industries of Florida.
Protecting and sustaining natural resource and environmental systems.
Enhancing the development of human resources.
Improving the quality of human life.
The multi county citrus agents have a new website up!
Here you will find access to current newsletters from each of our six
county extension agents as well as archives of past issues, bulletins,
events, and updated events log that highlights activities that would
be of interest to the citrus growing community in Florida.
Two new insecticides have recently received labeling for controlling Asian Citrus Psyllid in
Citrus; FMC's Mustang Max and Cheminova's Dimethoate 4E. Both products have limited
testing in Florida for control of Asian citrus psyllid, but initial results are promising. Ento-
mologist at the University of Florida are continuing to evaluate these products under Florida
RESTRICTED USE PESTICIDE
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EPA Reg No W04-27,0-677,6
EPA ".g," 27"-1 N
June 24, 2008
for CEU and Worker Protection Standards Training needs.
At the Lake County Agricultural Center-Tavares, FL
CEU DAY REGISTRATION FORM
June 28, 2008
$20.00 a session (per person and non
COMPANY refundable) Deadline June 26, 2008
Indicated which sessions) you wish to attend:
Please detach and mail completed form
with payment to: Lake Agricultural
Lake County Extension
1951 Woodlea Road
Tavares, FL 32778
ALL Individuals needing special accommodations to
participate in program should contact Maggie Jarrell
at 352-343-4101 five (5) working days before
Amount Enclosed: $
1 CEU in Ag Row Crop, Ag Tree
8:20-9:10 a.m. "Identification and Control of Invasive Weeds" Martha Thomas, Crop, Natural Area, Forestry
UF/IFAS Lake County Livestock Agent 2 CEU's in Demo & Research,
O&T, Private Applicator, Right of
9:10- 10:00 a.m. "IPM in Ornamentals" Steven Arthurs, Ph.D, University of Way, Limited L&O, Limited
Florida/IFAS Mid-Florida Research & Education Center Landscape & Maintenance, L&O
10:00 10:20 a.m. BREAK
2 "Pesticide Mixing and Loading"
10:20-11:10 a.m. Gary England, University of Florida/IFAS Sumter County
Horticulture Agent 2 CEU's in Core
11:10-Noon "Laws and Regulations and Pesticide Labeling" Dana Venrick,
University of Florida/IFAS Volusia County Commercial
Noon- 1:00 p.m. Lunch (ON YOUR OWN)
AFTERNOON CONCURRENT SESSIONS (Choose Only One)
3 "Aquatic Weeds and Pesticides Update" Tina Bond, DPM,
University of Florida/IFAS Osceola County Extension 2 CEU's in Aquatic, Private
1:00 3:00 p.m. Applicator
4 "General Household Pest Control Update" Bob Kessler, Bullseye
Environmental 2 CEU's in GHP, Limited Structural
1:00 3:00 p.m.
5 WORKER PROTECTION STANDARDS/TRAIN THE TRAINER 2 CEU's in Aerial, Ag Row, Private
Ryan Atwood, University of Florida/IFAS Multi-County Applicator, Soil & Greenhouse,
1:00- 3:00 p.m. Extension Forestry, Ag Tree Crop, O&T
Location & Contact Information
1951 Woodlea Rd.
Tavares, FL 32778-4204
The Lake County Extension Office is located just north of the Florida Turnpike, between 1-75 and 1-4.
From the Turnpike, take Exit #289, Leesburg North (US-27) to US-441. Where US-27 and US-441 merge, take
US-441 South to Tavares. As you enter Tavares, veer off to the right on Old 441. Turn right at the first traffic
light onto SR-19, heading south. Turn right again at the third traffic light at Woodlea Road. The Extension
Office--a cream-colored one-story building--is on the left.
From 1-75, take Exit #329, SR-44 East. Where US-27 and US-441 merge, take US-441 South to Tavares. As you
enter Tavares, veer off to the right on Old 441. Turn right at the first traffic light onto SR-19, heading south.
Turn right again at the third traffic light at Woodlea Road. The Extension Office--a cream-colored one-story
building--is on the left.