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.
Summer 2008 UF
July, August, &
Lake County Extension
I want to thank all of you for your support of our extension programs and IFAS. I am particularly grateful that
you voiced your opinion on the budget situation. IFAS received it's share of the budget cuts, but it was ex-
actly that...fair! I truly believe that if it were not for those of you who called and wrote letters to Dr. Machen
and your local politicians IFAS' budget would have been cut in disproportion to the rest of the University. I
am grateful to work with such dedicated people. I promise that I am equally as committed, working hard for
you growers, striving to be the best extension agent that I possibly can. Thanks for your support!
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 continue to monitor understory citrus trees in Central Florida that were abandoned many years ago and now
reside under pine stands. From the sticky traps and observations I have made, it is my conclusion that a small
population of psyllids do live in these trees during times of flush. Psyllid counts made from the sticky traps
have been relatively small considering no type of psyllid control measures. Also sticky traps that were hung
and counted later in the Spring (May-June) had no psyllids, during this time period we had relative little to no
rainfall in these areas. I had some question on these locations and I thought I would elaborate in more detail.
My two primary sites are located in Orange and Lake counties. One location is under pine and the other is a
block of abandoned grapefruit. The under pine trees are located approximately 0.25 miles from an actively
managed citrus grove. It also has an approximate density of 25 trees to the acre under the pine canopy. There
is around 100 acres of this type of arrangement (pine with citrus understory) within a (1) one mile radius. So
this location is not isolated. The abandoned grapefruit block is located in an area with multiple actively man-
aged groves located within a (1) one mile radius. Both sites in my opinion would be typical of other aban-
doned or understory trees that would be found in different part of Central Florida. The abandoned grapefruit
grove also had no flush during the dry spring for psyllids to reproduce on and I could not find any psyllids dur-
ing my scouting efforts. I will continue to monitor psyllid population levels throughout the summer and fall
months to report the annual cycle in these areas.
SA 4 Pherocon AM No-Bait Traps are
I used to monitor psyllid population
--- *- *- levels. They can be a tool to help
Syou make decisions concerning
your psyllid control spray pro-
gram. Make sure to purchase the
It No-Bait traps as the baited traps
S with be full of flies after a 24 hour
h J t period. The traps cost around a
dollar and can be purchased from
r Trece Inc. Phone: (866) 785-1313
Great Lakes IPM: (800) 235-0285
SObserved psyllids on traps during
the early spring. A magnifying
lens is required for id.
2007 FSHS Citrus Sections Best Paper: Georeferenced Ground Pho-
tography of Citrus Orchards to Estimate Yield and Plant Stress
for Variable Rate Technology. Proc. Fla. State Iort. Soc. 120:56-63.
2007 ARNOLD W. SCHUMANN*, KEVIN HOSTLER, JUAN CARLOS MELGAR AND JAMES SYVERTSEN
This past June I attended the Florida State Horticulture Society (FSHS) meeting. As usual I found
it to be full of good research information. Some citrus growers attended but overall it was a
small number. I think that the information presented is of value to growers and the opportunity
to interact with researchers one on one is good as well. In the spirit of promoting the FSHS meet-
ing, below is the abstract written by the authors (above) of the 2007 Best Paper from the citrus
section FSHS annual meeting.
Citrus canopy measurements with ultrasonic and optical sensors are being used in Florida
to control the placement and rate of fertilizers and pesticides with variable rate applica-
tion (VRA) spreaders. A significant reduction of fertilizer or pesticide consumption is pos-
sible simply by applying agrochemicals only to orchard space occupied by trees with
dense canopies. Additional refinement of agrochemical VRA may also be possible if fruit
load (especially on alternate bearing trees), flowering intensity, and leaf nutrient stress
could be measured on the tree canopies. Detection of early (mild) water stress before leaf
wilting becomes visible and reduces yield, could be used to schedule irrigation, manipu-
late flower and leaf flushes, or improve fruit quality. In this study we developed ground-
based digital photography systems to study the characteristics of citrus tree canopies over
large areas. A color digital camera mounted on a moving vehicle was used to capture geo-
referenced overlapping images of tree canopies in entire orchards. Images were stored on
a laptop computer and were processed using red-green-blue (RGB) pixel ratios and
thresholds to identify and quantify numbers of mature fruit. A monochrome digital camera
with visible and near-infrared bandpass filters was used to develop a multispectral imag-
ing system capable of rapidly detecting early water stress in tree canopies. Significant
correlations were achieved between the water stress index developed with the camera sys-
tem and stem water potential measurements used for quantifying water stress in citrus
trees. The water stress index could also detect, quantify, and map the severity of blight
disease in orchard trees for an entire block.
The use of new technology for increasing efficiency in agricultural production in Florida and the
rest of the country is important and will become more important to compete with the rest of the
world. In the U.S. we do not have the cheap labor that is available in other parts of the world.
However, we do have technological ingenuity which can help reduce our agricultural inputs and
increase our outputs, giving greater returns in agricultural operations. The use of technology for
agriculture processes will play an increasing important role in the future.
J0 Meeting- July 15th 5-7PM
Volusia Co. Extension Office
Please plan on joining us in Deland at the Volu-
sia County Extension Center on SR 44 on July
15th from 5 PM to 7 PM. The program will fo-
cus on greening management research. A free
dinner will be provided. Please call Maggie
by July 10th to register 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
5:45-6:00 Initial results of ULV for psyllid
6:00-6:30 What we are learning about HLB
pathogen in citrus plants
-Dr. Megan Dewdney
6:30-7:00 HLB symptomatology and plant nut
rition and thoughts on the Brazil cit
rus industry -Dr. Tim Spann
Directions to the Volusia Co. Extension office:
From I-4 West, take Exit #118 to get onto State
Road 44 (E. New York Avenue) heading east.
The Extension office is about 14 of a mile down
the road, on the right.
USDA Research Grove Tour
Groveland July 17th 8-10AM
There will be a tour of the A.H. Whitmore Flor-
ida Citrus Research Foundation Farm
(Whitmore farm) on Thursday July 17th from 8-
10AM. The Whitmore farm is currently used
exclusively by scientists in the USDA, ARS Ge-
netic Improvement of Citrus CRIS project. A
collection of more than 500 important citrus
scion and rootstock varieties is maintained at
the farm. This material serves as an important
resource for the program. Several green-
houses that are compliant with DPI regulations
at the farm are used to produce seedlings and
grafted trees that are used in field trials. Field
trials are conducted with individual own-
rooted seedlings as well as replicated trials of
grafted trees. A new effort to reduce the juve-
nility period and thereby shorten the time re-
quired for initial selection has recently been
initiated. If you would like to ride in the van
from the Agricultural Center in Tavares, please
respond to Maggie at 352-343-4101 or
firstname.lastname@example.org. We will be leaving the Ag.
Center at 7:30 AM.
Have you seen any fruit with these symptoms?
I received some grapefruit and Valencia oranges that
had damage similar to the fruit on the left. I spoke to
this grower to try and get this pest identified by uni-
versity scientists. The grower sent in a box of fruit
however we were unable to isolate the pest to iden-
tify. I was speaking with a different grower who said
some of his fruit had similar damage. If you have
seen any fruit with similar symptoms please give me
a call. I would like to try and collect a sample (most
likely will not see this until next spring) for identifi-
Pesticide Applicator Review and Exam
Orlando Aug. 21st
A pesticide license is required by any per-
sons who apply or supervise the application
of restricted use pesticides for agricultural
production. This certification requires a pass-
ing grade of 70% on the General Standards
and Private exam. This certification must be
renewed ever 4 years either by testing or by
There will be a review and exam in Orlando
on August 21st. The review starts at 8:30 AM.
There is a $20 charge for the class.
It is advisable to purchase the "Applying pes-
ticides correctly" and "The private applicator
training manual" from the IFAS bookstore on-
line at www.ifasbooks.ufl.edu or by calling
The private agricultural license itself costs
$60 which does not have to be paid until after
you pass the exam. To register please call
Celeste White at 407-254-9200.
OJ Meeting- September 9th 5-7PM
Lake Co. Extension Office
Please plan on joining us in Tavares at the Ag-
ricultural Center on September 9th from 5 PM
to 7 PM. The program will focus on citrus eco-
nomics with specific emphasis on the cost of
greening management. Should you reset
your grove? What do economist feel future
fruit prices will be? A free dinner will be pro-
vided. Please call Maggie by September 5th
to register 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!
5:45-6:10 Citrus fruit price outlook
-Dr. Tom Spreen
6:10-6:35 Economic analysis of greening
management and control
6:35-7:00 Economic analysis of resetting
versus not resetting groves
Multi County Extension Agents Greening and Canker
September 30th 10AM-Noon followed by free lunch at Lake Co. Extension Office
Please plan on joining the citrus multi county extension agents in Tavares at the Agricultural
Center on September 30th from 10AM-Noon for a Statewide Citrus Greening and Canker Man-
agement Update. A free BBQ lunch will follow the program. Please call or email Maggie by Sep-
tember 26th to register. It is important to let us know that you are planning on coming so we can
order the appropriate amount of food. Make the call today! Topics include last information on
psyllid control including ULV applications, product effectiveness trials, micronutrient effects,
open hydroponic systems, leafminer pheromone update, hedging/topping effects, and more.
J nage 7
Climate information for managing risks symposium:
Partnerships and solutions for agriculture and natural resources
Earlier this month I attended the climate infor-
mation for managing risks symposium. I was
hoping to stay current with any information
that might factor into our Weather Watch pro-
gram and help with managing freeze risks in
Central Florida. I am not sure that objective
was met but I did learn some thought provok-
ing things that I thought I would share.
There was a lot of talk of climate change and
climate variability, many of the scientist pre-
sented their research results concerning
these issues. There seemed to be a theme
that severe climate may be coming more
common, many pointed to the recent flooding
in the plain states as an example. One line
that was used is that these one hundred year
events are occurring on a more frequent ba-
There were also some conflicting view points
on as to whether or not climate change meant
that warming or cooling was or would take
place. Seems that many of the researcher's
models are predicting temperatures above
the historical averages. Weather records are
a relatively recent data set in the overall his-
tory of mankind. A scientist from the Univer-
sity of South Florida presented on techniques
using core samples from Florida lakes to trace
some temperature fluctuations over thousands
of years. He even made the statement that the
subtropical line could move from the I-4 corri-
dor to south Georgia. This statement seems
wild to me, but if it did can you say south
Georgia citrus production. A wild idea.
Of more interest to me (maybe because it
was easier for me to understand) was the is-
sue of potential carbon credits. Much has
been made on carbon credits in other ven-
tures such as forestry, but lately talk has in-
cluded agricultural producers. For those that
are not current with this topic there is a car-
bon exchange in Chicago were carbon cred-
its can be bought or sold (similar to the stock
exchange). Those who produce excess CO2
emissions (such as factories) can buy CO2
credit from "green" landowners. Since agri-
culture requires fertilizer, pesticides, harvest-
ing, fuel using production equipment, and
power for wells; they have traditional not
been included in the CO2 credit debate.
At this conference there was mention of agri-
culture being exempt from carbon regulation
(not sure if this is a proper term) and also
mentioned that there may be potential for a
rebate if agricultural producers were efficient
in the use of production inputs. Who will set
these production input limits? I don't know
and I am not sure anyone does at this point in
time, as it is just an idea being thrown around.
However, it is worth paying attention to as
there is the possibility of future consequences
in agricultural production and potentially
some income generated from carbon credits.
I think the take home message is there is
much, much more research needed to under-
stand climate variability and its potential ef-
fect on agricultural production on a regional
level. This is a topic that while somewhat un-
proven, controversial, and long term in scope
is worth keeping an eye. It maybe in the fu-
ture that carbon regulations and carbon cred-
its impact the way that we produce agricul-
ture in Central Florida.
Local Harvest a internet Farmers Market- Potential tool for
I recently learned of the local harvest website http://www.localharvest.org/. It is a online
market place for agricultural producers. It could be an alternative source of direct marketing
some of your fruit. It has community cooperatives, restaurants, farms, and grocery store di-
rectories. It serves as a type of online farmers market. When searching Tavares, FL it brings
up familiar local businesses such as Long and Scott farm in Zellwood and the local farmers
market in Eustis. When searching citrus in Florida familiar names such as the Orange Shop in
Citra and unfamiliar names to me such as Kumquat Growers in Dade City. Overall there are
not many producers listed and may offer an opportunity as an avenue to sell your fruit for a
small farmer. An old wise extension agent told me the best citrus growers were the ones who
knew how to market their fruit.
Citrus Research gets funding plus top scientific advisors from
around the country are getting involved.
Show me the money! This was a famous line in the movie Jerry McGuire which was based on
a the life of a sports agent. Jerry (the agent) was talking to one of his clients. The client was
telling him to get a contract with lots of money. For most things in life money is a necessity
and the more you have the more you can accomplish. That is why the funding by the DOC of
20 million dollars dedicated to greening research is huge. The past year greening research
was funded at the tune of seven million dollars and this research has lead to a better under-
standing of greening disease and its vector the Asian citrus psyllid. With 20+ million dollars
the Florida citrus industry has caught the attention of scientists around the world. The box tax
proposal period has begun and these proposals will be evaluated with the help of the Na-
tional Academy of Science (NAS).
Since 1863, the leaders of our country have turned to the National Academy for advice on the
scientific and technological issues. Most of the institution's science policy and technical work
is conducted by its operating arm, the National Research Council, created expressly for this
purpose. These are non-profit organizations which provide a public service by working out-
side the framework of government to ensure independent advice on matters of science, tech-
nology, and medicine. They enlist committees of the nation's top scientists and other experts,
all of whom volunteer their time to study specific concerns. The results of their efforts have
inspired improvements in Americans health, education, and welfare. The Academy's service
to government has become so essential that Congress and the White House have issued leg-
islation and executive orders over the years that reaffirm its unique role. The NAS will serve
in an advisory role to the Box Tax Committee who still has the final decision on citrus green-
ing funding. Now the that there is money for research, soon it will be "show me the results"!
Lake County Agricultural Center
1951 Woodlea Rd.
Tavares, FL 32778
Y3age 9***************** **********
S mmet 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-
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 website.
Also the Central Florida citrus extension website is much
improved and will continue to be updated & improved.
This summer I have been exploring possible enhancements to the weather watch program. The
company that I bought my Nextel from has agreed to offer a discount for citrus growers who
are participating in my Weather Watch Program. They are willing to waive the $36.00 activa-
tion fees and give a discount of $25.00 off each phone purchased. The nice part of having a
Nextel with direct connect is that it allows for me to talk with a group of growers (19 growers
+ myself) during a freeze event. If you are interested in having direct connect capable phone
please contact Mary Graham 352-636-3821 or Melinda Miller at 352-636-3224 with Afford-
I often get unusual questions or interesting op-
portunities to determine unique problems. I
thought I would share as the possibility of oth-
ers having the same question may exist.
Question: What are these snails?
Answer: Bradybaena similaris, which is an
introduced Asian snail.
These snails tend to eat tender young shoots of
herbaceous plants. They also scrape yeast and
algae of leaves and hard plant surfaces. They
do NOT hurt citrus trees.