St. Lucie County Extension 8400 Picos Road, Suite 101, Ft. Pierce, FL 34945-3045
772 462-1660 http://stlucie.ifas.ufl.edu
Treasure Coast Citrus Notes
Inside this Edition
2009 Citrus Expo PowerPoint Presentations
2010 Florida Citrus Show
Citrus Mechanical Harvesting Workshop
Food Safety Training for Citrus Growers/Harvesters/Packers
Low Volume Application Technology for Citrus Pests Workshop
Brown Rot Management
CHRP Shipping Fruit to Europe
Soil and Tissue Sampling
What's the Farmer's Share?
Pesticide Applicator Training
2009 Citrus Expo PowerPoint Presentations
Most of the PowerPoint presentations from the recent 2009 Citrus Expo in Ft. Myers are now
posted on the Extension Citrus Website. If you didn't make the show, you can still get an idea
about what sort of information the presenters were focused on. To get to the website, click on
the following hyperlink:
2010 Florida Citrus Show
While we're on the subject of presentations, the former Indian River Citrus Seminar is going to
be called the Florida Citrus Show in 2010. The venue for 2010 will again be the Havert Fenn
Center in Ft. Pierce and the 2-day show will be held on January 27- 28, 2010. Much more
information will be forthcoming in the next several months.
Citrus Mechanical Harvesting Workshop
Harvesting activities for the 2009-2010 season are just around the corner. We have scheduled
a Citrus Mechanical Harvesting Workshop to be held on Thursday, September 24 at the Indian
River Research and Education Center, 2009 S. Rock Road in Ft. Pierce.
About 8% of the citrus crop is currently mechanically harvested in Florida. This volume is likely
to increase as the technology and economics improve. Please let your harvesting contractors
know about this meeting in the event that I don't have them on my mailing list.
Citrus Mechanical Harvesting Workshop
Thursday, September 24
Indian River Research and Education Center
9:30 AM Registration and Welcome
9:45 -Concerns on Tree Health,
Dr. Juan Carlos Melgar, CREC
10:15 Abscission Chemical Update,
Dr. Bob Ebel, SWFREC
10:45 Current Machinery and Machine Enhancements,
Dr. Reza Ehsani, CREC
11:15 Mechanical Harvesting Economics,
Dr. Fritz Roka, SWFREC
Training for Citrus Growers/Harvesters/Packers
Those entities that are shipping fruit to international markets may find that they are must
ensure that their employees receive additional training related to food safety and Good
Agricultural Practices (GAP's). This training will include Personal Hygiene, WPS/PPE and
Canker/Greening Identification & Decontamination topics to satisfy portions of GlobalGap or
EurepGap audit requirements.
Check with the individual in your organization responsible for these audits to find out if your
production and harvesting personnel require this training. Now is the time to get this issue
taken care of before you get busy harvesting and packing. Individual certificates will be
awarded upon completion of the training to provide documentation for audits.
Training sessions (English & Spanish) are scheduled for September 25 and October 2, 2009 at
the Indian River Research and Education Center, 2199 Rock Road, Ft. Pierce, FL. We're
expecting large crowds for both sessions, so please Pre-Register by calling Dr. Mark Ritenour
at (772) 468-3922, ext. 167 or email: ritenour(@ufl.edu.
A copy of the program announcement and agenda is available by clicking on the following:
httD://Dostharvest.ifas.ufl.edu/Events/Hvaiene WPS Canker Greenina Trainina Fall09.odf
f^ / UNIVERSITY of
Presented by the Florida Cooperative Extension Service
Muti-County Citrus Extension Agents
RorW Citu EntMult n Aemtb
Ni mid srm
Low Volume Applicaton Technology
for Citrus Pests
Low Volume Labeled Materials
Low Volume Application
Attendees wi receive :35 C ntining Education Units (CEUs) fwr the Restricted Pestidfe and Certified Crp Advisor Licenses.
Meeting Dates and Locations
Lake County Extension Service Office
Southwest Forida Research & Education Center
Polk County Stuart Conference Center
Indian River Research & Education Center
Turner Agri-Civic Center Exhibion HIll
BertJ. Harris AgricutLral Center
1911 Woodlea Road
2685 SR 29 North
1702 Hwy 17-98 South
2199 S. Rock Road
2250 NE Roan Street
4509 George Boulevard
For more inflation, pease conct the local muti-ounty citrus extension gents
(Florida multi-county crtru or horticultra agents)
Steve Futch (Lake Alfred) 863-956-1151 Mongi Zekri (La Belle) 863-674-4092
ChaisOswalt (Barto 863-519-8677 Ryan Atwood (Tavares) 352-343-4101
Gary England (Bushnell) 352-793-2728 Tim Hurner (Sebnng) 863-402-6540
Tim Gaver (Ft Pierce) 772-462-1660
To register for a specific location. please contact:
Lake County Extension Service
Hendry County Extension Service
Polk County Extension Service
St Lucie County Extension Service
DeSoat County Extension Service
Highlands County Extension Service
Registration is required to plan for the lunch!
Register for the workshop in your area today and visit the Low Volume Application Webpage:
Brown Rot of Fruit1
Management of brown rot, caused by Phytophthora nicotianae or P. palmivora, is needed on
both processing and fresh market fruit. While the disease can affect all citrus types, it is usually
most severe on Hamlin and other early maturing sweet orange cultivars. See also PP-156
Phvtophthora Foot Rot and Root Rot.
Phytophthora brown rot is a localized problem usually associated with restricted air and/or
water drainage. It commonly appears from mid-August through October following periods of
extended high rainfall. It can be confused with fruit drop due to other causes at that time of the
year. If caused by P. nicotianae, brown rot is limited to the lower third of the canopy because
the fungus is splashed onto fruit from the soil. P. palmivora produces airborne sporangia and
can affect fruit throughout the canopy.
Early season inoculum production and spread of Phytophthora spp. are minimized with key
modifications in cultural practices. Skirting of the trees reduces the opportunity for soil-borne
inoculum to contact fruit in the canopy. The edge of the herbicide strip should be maintained
just inside of the dripline of the tree to minimize the exposure of bare soil to direct impact by
rain. This will limit rain splash of soil onto the lower canopy. Blocks with overhead irrigation
should be converted to undertree microsprinklers to avoid the promotion and spread of
inoculum in the canopy. Boom application of herbicides and other operations dislodge low-
hanging fruit. Fruit on the ground becomes infected and produces inoculum of P. palmivora
that can result in brown rot infection in the canopy as early as July while fruit are still green.
The beginning stages of the epidemic are very difficult to detect before the fruit are colored and
showing typical symptoms. Application of residual herbicides earlier in the summer may reduce
the need for post-emergence materials later and minimize fruit drop throughout this early stage
of inoculum production from fallen fruit.
Usually a single application of Aliette, Phostrol or ProPhyt before the first signs of brown rot
appear in late July is sufficient to protect fruit through most of the normal infection period. No
more than 20 Ib/acre/year of Aliette should be applied for the control of all Phytophthora
diseases. Aliette, Phostrol and ProPhyt are systemic fungicides that protect against
postharvest infection and provide 60-90 days control. Copper fungicides are primarily
protective but are capable of killing sporangia on the fruit surface and thus reducing inoculum.
They may be applied in August before or after brown rot appearance and provide protection for
45-60 days. If the rainy season is prolonged into the fall, a follow-up application of either
systemic fungicides at one-half of the label rate, or copper in October may be warranted. With
average quality copper products, usually 2-4 Ib of metallic copper per acre are needed for
Precautions should be taken during harvesting not to include brown rot-affected fruit in the field
containers as this could result in rejection at the processing or packing facility.
Recommended Chemical Controls for Brown Rot of Fruit
Pesticide MOA2 Rate/Acre1
Aliette WDG 13 5 Ib
Phostrol 13 4.5 pints
ProPhyt 13 4 pints
copper fungicide M9 Use label rate.
1Lower rates may be used on smaller trees. Do not use less than minimum label rate.
2Mode of action class for citrus pesticides from the Fungicide Resistance Action Committee
(FRAC) 2003. Refer to ENY624, Pesticide Resistance and Resistance Management, in the
2009 Florida Citrus Pest Management Guide for more details.
12009 Citrus Pest Management Guide: Brown Rot of Fruit, J.H. Graham and L.W. Timmer,
Shipping to Europe for the 09/10 seasonP
SIf you plan to ship fresh citrus to the European Union, you will need to have
your grove blocks) inspected prior to harvest.
SCall a few weeks ahead of your estimated harvest date to request a
pre-harvest survey and harvesting permit.
SPermits (to begin harvest) will be good for 120 days if the surveyed grove
block with 50-foot buffer is found free of citrus canker.
SPlease contact your local CHRP office when you are ready to schedule a
Harvesting Permits are only required for EU shipments.
Avon Park, FL Tavares, FL
863-314-5900 352-253-4547 Winter Haven, FL
Immokalee, FL Vero Beach/Ft Pierce 863-298-7777
_ DiywiVn of
0 PLANT INDUSRY 1-800-282-5153 www.fl-dDi.com/chir
Charm H BoBnlo n, Cot mms ior 1
Citrus Grove Leaf Tissue and Soil Testing: Sampling,
Analysis and Interpretation1
Fertilizer use efficiency in Florida citrus groves can be enhanced by "program fertilization,"
where annual fertilizer applications are scheduled after considering a number of grove
characteristics. The information necessary to formulate an efficient fertilization program for a
particular grove includes tree age, past production, fertilization history, and diagnostic
information. This fact sheet details the value of grove nutritional diagnostic information in
determining fertilizer programs that increase fertilizer efficiency while maintaining maximum
yield and desirable fruit quality.
Usefulness of Leaf-tissue and Soil Testing
Leaf tissue testing is useful to evaluate tree nutritional status with respect to most nutrients, but
is particularly effective for 1) macronutrients, primarily nitrogen (N) and potassium (K), that
readily move with soil water, and 2) the micronutrients copper (Cu), manganese (Mn), zinc
(Zn), and iron (Fe). Leaf tissue analysis is a much better indicator of the effectiveness of soil-
applied fertilizer for these elements than soil analysis. In addition, if particular elements have
not been applied as fertilizer, leaf tissue analysis indicates the availability of those nutrients in
the soil. An annual leaf tissue sampling program can establish trends in tree nutrition resulting
from fertilizer practices carried for several years. Both leaf tissue and soil testing can be
valuable, but leaf analysis provides more useful information about citrus nutrition than soil
analysis. With the results of a soil test, one tries to predict how much of a particular nutrient will
be available to plants in the future. Predictive soil testing works best with 1) short term crops,
and 2) nutrients which are not very mobile in the soil. Thus, for long-term crops such as citrus,
predictive sampling should be used for only those nutrients which have slight mobility in most
soils, including phosphorus (P), calcium (Ca), and magnesium (Mg).
Leaf-tissue Sampling Programs
The benefits of leaf tissue sampling are fully realized by establishing an annual sampling
program. In this way, trends in tree nutrition over several years may be noted. The grove
should be sampled to minimize soil and tree type variability. The sampling scheme is the one
area of the nutritional testing process controlled by the individual taking the sample. Thus, the
manager needs to ensure that the leaf sample is representative of a particular area. For
sampling purposes, the grove should be partitioned into management units of not more than
20 acres. Each unit should contain similar soil series and scion/rootstock types. For small
groves, the entire grove may be partitioned into these units, and a sample taken from each.
For large groves, where sampling the entire grove is unfeasible, indicator blocks may be used.
The standard leaf sample consists of at least 100 four- to six-month-old spring flush leaves
taken from non- fruiting twigs. If the majority of the spring flush occurs in March, the best time
to sample leaves would be July through September. About 15 to 20 trees should be
sampled within each management unit. The time of year for leaf and soil sampling coincides
and can be accomplished during the same trip through the grove. It is convenient to remove
leaves from the same trees under which soil samples are taken.
Analytical Procedures for Leaf Samples
If samples require hand-washing (necessary for accurate Fe determination), it is best done
when the leaves are still in a fresh condition. Laboratories do not normally hand-wash leaves,
so washing should be done by the person taking the sample at the time he/she takes the
sample. When the sample arrives at the laboratory, the following steps are typically taken: 1)
the leaves are dried and finely-ground; 2) a known weight of tissue is either digested in acid
(for N analysis) or ashed in a furnace (for all other elements); 3) the concentration of elements
in the digest or ash are measured; 4) nutrient concentrations are expressed as either
percentage or parts per million (ppm) in the tissue. Procedures for plant tissue analysis usually
do not vary among laboratories because the entire amount of each nutrient in the leaves is
measured. Thus, results from different laboratories can be directly compared.
Well-defined categories of classification for citrus leaf tissue analysis values from mature,
bearing trees exist from years of experimentation in Florida and California. The categories are
"deficient," "low," "optimum," "high," and "excess." Remember that this classification applies
only to the standard age leaf sample taken from mature trees as described above.
The categories are not valid for young, nonbearing trees. Maintenance of leaf sample
elemental concentrations in the "optimum" range is desirable. Those consistently above this
range indicate possible over-fertilization. Analysis values can be interpreted by the grower and
fertilization rates adjusted in the appropriate direction, such that future leaf values reach the
As with leaf sampling, the benefits of soil sampling are fully realized if samples are taken
annually from the same production units (or indicator blocks), because trends in soil pH or
extractable nutrients can be established. The traditional soil sampling technique is as
follows: One 6-inch deep soil core is removed from the dripline (within the herbicide band) of
15 to 20 average" trees scattered throughout the block. The cores should be composite into
the same bag and air-dried before being sent for analysis. Samples should be taken in the
latter part of the summer rainy season (July-September), before fall fertilization.
A soil test interpretation verbally explains the relative meaning of soil test values. Interpretation
uses the categories "very low," "low," "medium," "high," and "very high" to relate to various
levels of an extracted nutrient. However, soil test results have no meaning unless they are
calibrated with crop response. The category "very low" indicates that the
soil can supply little of the Crop Nutrient Requirement (CNR), thus most of the nutrient must
come from applied fertilizer. The categories "low" and "medium" mean that proportionally more
of the CNR can be supplied from the soil, resulting in reduced need for fertilization. When a
soil tests "high" or "very high," all of the CNR can be satisfied from the soil alone and no
fertilization with that nutrient is required.
Soil and Leaf-tissue Sampling Checklist
1. Sampling programs are most effective if done annually.
2. Use leaf tissue testing for all nutrients, especially the mobile soil nutrients (N and K) and
micronutrients (Cu, Fe, Mn, and Zn).
3. Use soil testing for pH and immobile soil nutrients (P, Ca, and Mg).
4. Use the standard sampling procedures for soil and leaves described in this fact sheet.
5. Be aware that spray residues or dust on leaf surfaces affect sample results; wash leaves for
accurate Fe analysis, and avoid leaves with spray residues.
6. Be aware that a number of soil extracting solutions exist, and they can differ in their ability to
extract plant nutrients, especially P.
7. Test interpretations should be used to make fertilization or liming decisions. Wise use of the
analytical information allows optimal citrus production and minimizes the fertilizer pollution of
The above is a summary of "Citrus Grove Leaf Tissue and Soil Testing: Sampling,
Analysis and Interpretation", http://edis.ifas.ufl.edu/CH046, T.A. Obreza, A.K. Alva,
E.A. Hanlon, and R.E. Rouse, UF/IFAS
What's the Farmer's Share?
A new webpage on The Hand that Feeds Us website shows that U.S. farmers on average
only receive about 20% of the retail price of food products in the supermarket. For some
items, it is way less than that figure. Packaging and transportation are two significant factors in
the ultimate cost of a grocery item.
New Pesticide Training Webpage
We added a new page to the St. Lucie Extension Website last month with lots of good
information relative to Pesticide Application Safety and Certified Pesticide Applicator training
and licensing. The St. Lucie County Extension agents are committed to providing timely and
comprehensive training for our Certified Pesticide Applicator clients. Take a minute to click on
the following hyperlink and see all the sites we've gathered under one handy page:
General Standards (Core) Pesticide Applicator Training
Preparation for the General Standards Exam required for all of the Certified Pesticide
Applicator Categories. 2 General Standard CEU's will be offered for individuals who are
current license holders (This includes Private Applicator and Ag Tree Crop). Ken Gioeli,
Natural Resources Agent will be offering this course on Wednesday, October 7, 2009. Pre-
registration is required to help Ken prepare his handout materials and the cost is $20. Call
(772) 462-1660 for details and to pre-register.
Dates to Remember
Citrus Mechanical Harvesting Workshop, IRREC, September 24
Food Safety Training for Citrus Growers/Harvester/Packers, IRREC, September 25 &
Certified Pesticide Applicator General Standards Training, October 7
Low Volume Application Technology for Citrus Pests, IRREC, October 13
I'm not too proud to ask for a good representation of growers and managers for the Mechanical
Harvesting and Low Volume Application Technology Workshops (CEU's, CCA credits and
lunch offered for the LV workshop). Call (772) 462-1660 to pre-register! You will learn
something that you can use in your operation.
Just for Fun
Nugene was out duck hunting on the west side of Lake Okeechobee when he was approached
by the game warden, who asked to see his hunting license and federal duck stamp.
The warden looked at the license and handed it back. "This license is no good, it's for last
year", he said.
"That's okay," Nugene replied. "I'm only shooting at ducks I missed last year."
Billy Bob and Clyde were out on the lake fishing on beautiful Sunday morning when the church
bells started ringing out in the distance. Clyde looked over his shoulder at Billy Bob and said,
"Don't you feel kind of guilty being out here fishing when church is about to start?"
"Not really," said Billy Bob. "I couldn't have gone to church today, anyway."
"Why not?' asked Clyde.
"The wife is awful sick."
Take care, for OUr LIFE
Tim Gaver, Extension Agent II Citrus
UF/IFAS St. Lucie Cooperative Extension
(Click on the CITRUS tab at the upper left for my citrus section)
Ai Eq Oporlti / Af tive !Ation k ionstuion