The publications in this collection do
not reflect current scientific knowledge
or recommendations. These texts
represent the historic publishing
record of the Institute for Food and
Agricultural Sciences and should be
used only to trace the historic work of
the Institute and its staff. Current IFAS
research may be found on the
Electronic Data Information Source
site maintained by the Florida
Cooperative Extension Service.
Copyright 2005, Board of Trustees, University
SEPTEMBER 3, 1980
AGRICULTURAL RESEARCH & EDUCATION CENTER
P. 0. Box 1088 Lake Alfred, Florida 33850
SSTArE OF FLORIDA DEPARTMENT OF CITRUS
0I Lakeland, Florida
G In Cooperation With
SFLORIDA CITRUS PACKERS
COOPERATIVE EXTENSION SERVICE
INSTITUTE OF FOOD & AGRICULTURAL SCIENCES
UNIVERSITY OF FLORIDA, GAINESVILLE
c3 S-' /. '- -600-WFW
r`- 3Ac <
It is a great pleasure to me to welcome this group once again
to the Lake Alfred Center. We appreciate your interest and con-
stantly strive to present a more interesting program.
Two separate additional buildings will be under construction
by the time you meet here in 1981. One will be a laboratory-
office addition to this building, to house our plant pathology
and horticulture work. We are indebted to Senator Curtis Peterson
and other members of the Polk County Delegation for the Legisla-
ture's appropriation of 1.5 million dollars for the'construction
of this much-needed building.
The second building is to contain a replacement for this
auditorium, a replacement for our present library, and teaching
facilities. Some of you have attended meetings in this room for
over 30 years, and we hope that more comfortable surroundings will
be available in 1982. We will have a great deal of additional
space in our library, and facilities for both regular teaching
and adult education.
The second building is being funded by the citrus industry
through contributions. We have obtained about three-fourths of
our original goal of 1.5 million dollars for this project from
numerous donors, including growers, fresh fruit packers, and pro-
cessors. We are still short of our goal, but are working with an
assigned architect because of the good reception that we have
received so far.
Contributions to the building are being handled by the
University of Florida Foundation's agricultural program, called
"SHARE." If you would like to make a contribution to this worthy
and tax-deductible cause, please make your check to the
Lake Alfred Experiment Station Euilding Fund and send it to me
at P. 0. Box 1088, Lake Alfred, Florida. 33850.
In closing, I would like to express my appreciation to all
of the citrus industry, including today's speakers. It is a
privilege to work for you.
Herman J. Reitz,
As we near the beginning of another new
shipping season and indications point to a very
light crop in those groves damaged by the March
freeze, it emphasizes the unique quality of each
of our seasons. No two of them are ever exactly
alike, and therefore, our problems vary from year
to year. The task of our research staff, whether
I.F.A.S., Department of Citrus, or U.S.D.A., is
to recognize these problems before they occur and,
hopefully, have a solution ready for you whenever
you need it.
This is the one time each year when the
scientists of all cooperating agencies are
gathered together under the same roof. We hope
you will take advantage of this opportunity to
discuss your concerns with the appropriate
specialists, both in the formal meeting and
informally in the laboratories.
Welcome to Lake Alfred from all of us!.
ohn A. Attaway
Scientific Research Director
Florida Department of Citrus
Nineteenth Annual Citrus Packinghouse Day
University of Florida
Lake Alfred, Florida
and Education Center
Wednesday, September 3, 1980
Herman J. Reitz
Horticulturist and Director
Agricultural Research and Education Center
John A. Attaway
Director of Scientific Research
State of Florida, Department of Citrus
Richard Graves, Commissioner and Chairman,
Administrative and Budget Committee
Florida Department of Citrus
IMPROVEMENT OF AREC FACILITIES -
Dr. H. J. Reitz, Director, AREC, Lake Alfred.
See comments in "Foreword" on inside front cover of
10:10 A.M. USE OF GROWTH REGULATORS TO EXTEND
THE SEASON FOR QUALITY FRESH GRAPE-
FRUIT Mohamed A. Ismail, Florida
Department of Citrus, Lake Alfred.
Low concentrations of gibberellic acid (GA) and
2,4-D, applied in the late fall-early winter to grape-
fruit trees delay rind deterioration, thus, allowing
longer fruit storage on the tree. The effectiveness
of these applications, however, may vary from season
to season. Temperature and rainfall appear to be the
most important variables that influence fruit quality.
Supplemental irrigation during prolonged droughts, along
with nutritional foliar sprays, particularly of nitrogen
and potassium, seem to augment the desirable effects of
10:20 A.M. SOOTY BLOTCH AND GREASY SPOT OF GRAPE-
FRUIT J. L. Knapp, Extension Service
and J. 0. Whiteside, Agricultural
Research and Education Center, Lake Alfred.
The use of copper for.sooty blotch and greasy
spot control on fresh market grapefruit will be
Sooty blotch is a common occurring fungus which
grows deep within the waxy platelets on fruit surfaces.
It is not grouped with the sooty mold complex, does not
require honey-dew for development, and resists washing
off in the packinghouse.
Spores of the greasy spot fungus.have shown
resistance to Benlate after repeated use. DuPont has
recommended the use of fungicide combinations. IFAS
feels that there is no advantage of a combination over
the use of copper alone.
10:30 A.M. THE FUTURE OF THE ABSCISSION HARVESTING
PROGRAM W. C. Wilson, Acting Harvesting
Coordinator and J. A. Attaway. Director
of Scientific Research, Florida Department
of Citrus, Lake Alfred.
The citrus growers of the State of Florida by
referendum voted in favor of extending the taxing
program for abscission chemical-mechanical harvesting
research and development for an additional six years.
One area of research desired by all groups was increased
emphasis on abscission chemical research. The Department
of Citrus staff, therefore, has recommended certain
changes in the present program which will lessen emphasis
on mechanical development and will increase emphasis on
solving abscission problems. An additional plant
physiologist will be added to the DOC staff at Lake
Alfred and additional needed work will be contracted
through the U.S.D.A. in Orlando and the Fruit Crops and
Agronomy Departments at the University of Florida. All
projects will be coordinated by the DOC staff and
progress reports made to the Commission's Harvesting
Research & Development Advisory Committee.
An area of increased emphasis during the next
six-year period will be in finding chemicals or methods
of application which will cause less peel injury to
fruit. Except for Ethrel (ethephon), which has found
limited use on tangerines and tangelos, research
efforts of direct benefit to fresh fruit have not
been as successful as we had hoped. Most compounds
which loosen fruit with little or no peel injury
usually have caused excessive phytotoxicity (leaf
drop). Of all the citrus fruit with which we have
worked, the Dancy tangerine has proven to be the most
difficult to loosen successfully.
10:40 A.M. PICK IT RIGHT OR WE CAN'T HELP YOU -
Bill Grierson, AREC, Lake Alfred.
Only two hands are of critical importance in the
fresh fruit industry, all the rest of us who come
between them are secondary and dependent on these two
hands---The hand that takes the fruit off the tree and
the hand that picks it up in the store and pays the
money at the cash register.
Everyone is agreed on courting, pampering,
beguiling the bearer of the hand at the cash
register. But she (it is usually a lady) will pass
our fruit by if previous purchases had fruit that
rotted before they were consumed. When this happens,
the odds are high that such fruit decayed because that
first hand had plugged it, dropped it on the ground,
tossed it into a distant pallet box, or otherwise
abused that living fruit.
More and more, our skills as research workers
are going, not to reduce costs or improve the
product reaching the consumer, but to amend the increas-
ing damage being done during picking. This problem is
not limited to Florida. We hear complaints about the
declining quality of picking from citrus areas around
the world--from everywhere except Florida where,
ostrich-like, no one wants to admit the problem exists.
We are told constantly "We can't do anything
about the pickers." If the industry cannot cope with
the problem in the grove, please don't expect us to
cope with it in the laboratory.
10:50 A.M. THE STATUS OF POSTHARVEST FUNGICIDES -
Eldon Brown, Florida Department of
Citrus, Lake Alfred.
Several items relating to fungicides and decay
control will be discussed. Topics will include some
recent concerns of European countries with benomyl,
occurrence of benomyl resistant molds in our packing-
houses, and the effectiveness of fungicides applied in
water waxes. Decay control data with new experimental
materials will be reviewed. The economic occurrence of
Brown Rot, a decay of usual minor importance, will
also be reported.
11:00 A.M. FACTORS AFFECTING THE AMOUNT OF DIPHENYL
RESIDUE ON TANGERINES AND THEIR HYBRIDS -
Steven Nagy, Florida Department of Citrus,
Will Wardowski, Extension Service, Lake
Alfred and Jack Hearn, USDA, Orlando.
Sunburst, Osceola, Page, Honey, Dancy, Clementine x
Orlando, and Temple x Orlando cultivars were studied to
determine the effects of storage temperature, length of
storage, number of diphenyl pads packed per carton, and
other variables on the absorption of diphenyl.
The rate and extent of diphenyl absorption were
different for each of the tangerine cultivars. Storage
of fruit at-700F increased diphenyl absorption about 2-
10 times when compared to fruit stored at 40F. The
length of time that fruit can be safelyheld in storage
or during transit is dependent on the type of cultivar;
some can be stored for about 4 weeks, whereas others
should be stored no longer than 2 weeks. When fruit
were packed and stored under similar conditions (tempera-
ture, time, no. of pads packed), some cultivars showed
higher rates of decay than others; Dancy was extremely
susceptible to decay under our experimental conditions.
11:10 A.M. RECYCLING DRIER AIR TO REDUCE DRYING TIME
AND FUEL COSTS Edward MacKenzie, Brooks-
ville Citrus Growers' Association, Brooks-
During the last season, at Brooksville Citrus
Growers' Association, we have revised our packing
operation into a 300 box/hour Tangerine Line using
Water Wax and a 600 box/hour Orange Line using Solvent
Driers on both lines have been equipped with hot
air recirculation fans and ductwork and temperature
and humidity controls for proper drying and better
fuel economy. After six months operation on the
Tangerine Line and three months on the Orange Line,
results have been satisfactory.
Data on fuel usage per carton packed, steam heater
capacity required and drier hold-up time will be.
11:20 A.M. TRENDS IN CITRUS PACKERS.ENERGY USAGE -
Will Wardowski, Extension Service, Bill
Miller, Agricultural Research and
Education Center, Lake Alfred.
A year ago we reported the results of an energy
consumption survey completed by 44 Florida citrus
packers for the 1977-78 season. A second survey for
the 1978-79 season included those packers with the
most complete energy records for 1977-78. Data were
compiled for the various energy sources'; electricity,
natural gas and fuel oil. 'Comparisons between seasons
are made for individual packinghouses with attention
to implementation of energy-conserving practices.
Total energy consumption per carton packed was
11:30 A.M. YOUR FRUIT IN JAPAN John J. Smoot,
U.S. Department of Agriculture, SEA,
For the most part your fruit on the Japanese
market looks very good but, unfortunately, some
does not. In the 8 to 9 years Florida has shipped
grapefruit and other citrus to Japan, considerable
improvement has been made, including: 1) less
decay through better fungicide treatments; 2)
better-appearing fruit with less deformation by
use of flat packs and stronger boxes, accompanied by
palletization, unit handling, and lower stacking; 3)
better understanding of shipping and holding temp-
eratures; and 4) some realization that the consumer
is 10,000 miles and 4 to 6 weeks or more away. The
thorns in our sides which cause big problems are the
atrocious methods of harvesting, the logistics
involved in the required fumigation, and the
accumulating shiploads of fruit at the port; and,
beyond our control of course, the demand by the
Japanese consumer in competition with other fresh
11:40 A.M. THE FUTURE FOR CITRIS PACKERS Albin P.
Crutchfield, Alexander & Baird Co.,
Deland, and Commissioner and Chairman,
Fresh Fruit Committee, Florida Department
1. Fresh fruit generally popular. Consumers need to be
educated as to best varieties and time to buy.
2. Magic in the name ORANGE.
3. Change in marketing citrus crops since advent of FCOJ.
4. The future and what it promises in light of research
and development, particularly nutrition.
5. FRESH is ultimate standard of quality and taste.
6. Decline in per capital consumption of FRESH and reduced
number of FRESH shippers.
7. Increase in shipments of zipper skin varieties.
8. Possible solution and program for increasing FRESH
citrus acceptance and development of greater volume.
Advertising and merchandising based on dollar value
rather than box volume.
11:50 A.M. POSTER, EQUIPMENT AND FRUIT DISPLAYS -
Will Wardowski, Extension Service and
Bill Miller, Agricultural Research and
Education Center, Lake Alfred.
The exhibits have been expanded to include poster
and fruit displays by various research workers. This
will allow the entire afternoon to visit the commercial
and research exhibits and to talk with individuals
about their work. Research-oriented exhibitors have
provided abstracts included in this program. All
commercial exhibitors will be announced before the
This year a revised format is in effect for
commercial exhibitors. Previously the equipment
had to be "new" to the Florida citrus packing
industry. This constraint has been removed. If you
have exhibitors in mind for next year, contact James
Emerson, Florida Citrus Packers and he will ask the
membership to consider sending an invitation to that
CELL-PACK BOXES AND GRAPEFRUIT PRINTS -
Philip W. Hale, U.S. Department of
Agriculture, SEA, AR, Orlando.
Fresh Florida grapefruit were packed in experimental
cell-pack boxes and shipped under commercial conditions
from Florida to Tokyo, Japan. The cell-pack boxes
contained 3 layers of grapefruit and each layer contained
11 fruit for a total count per box of 33 fruit, one more
than the standard 4/5-bu place-pack box. Vertical chip-
board partitions placed in the cell-pack boxes and separate
by fiberboard layer dividers formed individual cells
for each grapefruit, and reduced overhead pressure on each
fruit. In all tests, the cell-pack boxes reduced the
amount of serious deformation of the fruit by 75% as
compared to fruit of like size and quality shipped in
the standard export box. Packaging, labor, and trans-
portation costs for the cell-pack box were $0.96 more
per standard box equivalent than for the standard export
box from Florida to Tokyo, Japan.
.Using carbon paper, grapefruit prints were made
of packing patterns for a guide in the placement of
ventilation openings in shipping boxes, layer separators
and biphenyl pads.
EXAMPLES OF DECAY IN CITRUS FRUIT -
Eldon Brown, Florida Department of
Citrus, Lake Alfred.
The purpose of this display is to illustrate the
various decays which can develop on Florida citrus.
A handout describing situations where these decays
may be expected to occur most frequently and suggestions
for control will be available.
THE DEVELOPMENT AND SPREAD OF MOLD
(Penicilliur spp.) IN CITRUS FRUIT
DURING CONTACT IN PACKED CARTONS -
Charles R. Barmore, Agricultural
Research and Education Center and
G. Eldon Brown, Florida Department
of Citrus, Lake Alfred.
Blue mold caused by Peniciliumwn itaZicum
spreads more frequently from infected to healthy fruit
during contact than does green mold caused by Penicillium
digitatun. Nutrients and organic acids present in
the exudate discharged from the infection site influenced
the frequency of decay spreading. Spread was also related
to surface mycelium development and extent of tissue
maceration (softening). Anatomical and pectolytic changes
during the decay and spreading processes are presented.
"UNI-PACK" INDIVIDUALLY WRAPPED STORAGE
OF GRAPEFRUIT Kaz Kawada and Gene Albrigo
Agricultural Research and Education Center,
The keeping quality of grapefruit is improved and
storage life can be prolonged by "Uni-Pack", i.e.,
wrapping individual fruit in a thin plastic film bag
which then can be heat shrunk.
"Uni-Pack" not only keeps freshness of grape-
fruit in terms of minimizing weight loss, softening,
peel color and gloss changes, but it also reduces fruit
deformation, chilling injury, and stem-end rot.
"Uni-Pack" prevents contact infection and so
called "soilage" (blemishing of sound fruit by mold
spores) problems caused by green mold, and make it
easy to discard spoiled fruit. "Uni-Pack" can also
make a very attractive brand-named consumer packaging.
A type of "Uni-Pack" has been done mechanically
in Israel and South Australia. They hope to use the
system as an alternative for refrigerated storage.
The additional cost of "Uni-Pack" may be easily
recovered on selected high-quality fruit particularly
if a wrapping machine is employed. Choosing the right
plastic film is critical. For the present, a 15 p
irradiated low density (high pressure) polyethylene
film seems to be best.
PRACTICAL METHOD OF REDUCING ETHYLENE
DIBROMIDE RESIDUE IN FUMIGATED CITRUS
DESTINED TO JAPAN M. A. Ismail,
Florida Department of Citrus and William
M, Miller, Agricultural Research and
Education Center, Lake Alfred.
All citrus exported to Japan has to be fumigated
with ethylene dibromide (EDB) as a protective measure
against infestation by the Caribbean fruit fly
(Anastrepha suspen&a). Fumigation is conducted in
specially constructed chambers at Wahneta or Fort
In 1979-1980, approximately 6 million cartons,
mainly grapefruit, were fumigated and shipped to Japan.
Estimated value of this fruit at the port of arrival
is $60 to $66 million.
EDB is currently listed by EPA on the Rebuttable
Presumption Against Registration (RPAR) list as a
suspected carcinogen. EDB may also cause citrus fruit
peel injury, resulting in reduced marketability and
substantial financial losses.
Research efforts at the Lake Alfred Center were
recently directed toward finding practical methods
for reducing the level of EDB in fumigated citrus
loads, mainly to minimize personnel exposure and peel
injury. These methods included the following:
1. Fumigation in a cattle trailer
2. Purging fumigated loads with a trailer evacuation
Both methods reduced EDB level in fumigated
grapefruit loads, but lower levels of the fumigant
were measured in loads fumigated in the cattle
trailer than in conventional trailers purged with a
trailer evacuation system.
ENERGY RESEARCH AND TOUR OF THE ROOF
TOP SOLAR ENERGY CONTINUOUS BELT
REGENERATOR William M. Miller,
Agricultural Research and Education
Center, Lake Alfred.
To perform an energy analysis for packing
fruit, the following information is required:
current energy consumption, efficiencies of current
processes and feasibility studies of conservation
techniques and non-fossil fuel sources. In citrus
packinghouses, dryers are a principal energy
consumer and are operated at low efficiencies. With
air recycling, energy consumption can be markedly
reduced and efficiencies approaching 50 percent achieved.
With future fossil fuel price increases, solar
energy may be economically justified. The solar
concept under development at AREC, Lake Alfred consists
of a flat-plate solar belt for material drying. The
materials dried are desiccants which can dehumidify air.
Dehumidified air is then used for surface moisture
drying of fruit, "A pilot system, approx. 200 ft2
collector area, using the solar drying-desiccant
dehumidification will be available for inspection
during the equipment/poster session.
LAKE ALFRED DEGREENING ROOM DESIGNS -
Bill Grierson, Agricultural Research
and Education Center, Lake Alfred.
The evolution of our current degreening room design
has been a truly cooperative endeavor as each advance
has been made only when some packers were willing to
gamble their money that the proposed change would work
out well. No way do we have funds to build, tear down
and rebuild experimental degreening rooms!
The current horizontal airflow, wall-duct design
has proved to have the following advantages:
1. Fruit degrees faster than with any previous design
(which minimizes decay and shrinkage and increases
packinghouse output during the degreening season).
2. Maximum use is made of floor space.
3. Energy use is reduced (about half the traditional
radiator capacity per box).
4. Rooms can be run continually, receiving green fruit
and delivering degreened fruit from a single large
5. Opening the front curtain or doors does not hinder
6. Clear traffic patterns maximize the amount of fruit
that each lift-truck can handle and minimize li.ft-
A tip of the hat to Coca-Cola Foods Division
(then.Minute Maid), Chase & Co., Lake Wales CGA, Alcoma
Packing Co., Haines City CGA and Sefco.
HARVESTING & HANDLING SECTION, STAFF
AND PUBLICATIONS IN FRESH FRUIT
RESEARCH AT LAKE ALFRED.
The nine faculty members listed on this display
are on three different payrolls but they work as an
effective team at the Agricultural Research and
Education Center, Lake Alfred. A number of their
publications will be found at this display and copies
of these publications are available on request from
W. Wardowski, AREC, P. 0. Box 1088, Lake Alfred, FL
DOES THE CITRUS RUST MITE PREDISPOSE
GRAPEFRUIT TO CHILLING INJURY? A.
C. Purvis, Agricultural Research and
Education Center, Lake Alfred.
An unusual pattern of pitting was observed in
several exterior canopy fruit harvested in January 1980
which contributed to both the speed of development and
severity of CI. Instead of being randomly located and
widely scattered over the surface of the fruit, a
typical characteristic of CI in grapefruit, the pits
were restricted to and generally covered an entire
hemisphere of the fruit. CI of these fruit was more
rapid (pitting occurring in less than 2 weeks) and more
severe than other fruit in the same lot. The pattern
of CI in these fruit was remarkably similar to the
pattern of rust mite damage on citrus fruit. Although
the fruit had no visible rust mite damage at harvest,
the fruit remaining on the tree after the test fruit
were harvested developed the characteristic bronzing
associated with rust mite injury within 2 to 3 weeks.
Does incipient rust mite injury predispose grapefruit
to CI? Experiments have been designed to quantitate
the dynamics of rust mite populations with susceptibility
of grapefruit to CI during the upcoming harvest season.
HARVESTING & HI-LIFT SAFETY VIDEOTAPES -
Robert F. Lee, Safety Coordinator, Groves
Operations, The Coca-Cola Company, Foods
The Coca-Cola Company Foods Division has produced
two videotape films to use in Safety training for fruit
The first film "Safety Your Ladder to Success"
(12 minutes), follows a picker from the time he leaves
home for work, getting ready to pick, picking, and other
general safety topics as they relate to Harvesting.
The film stresses both on and off-the-job safety.
The next film is "Hi-Lift Safety & Operations"
(17-1/2 minutes). This film is a part of our driver
improvement program for Hi-Lift drivers. It covers
preventive maintenance, safe operation, and proper
fruit loading techniques.
Both films are in English and Spanish and can
be shown on any television using a 3/4" videocassette
HEAT AND MOISTURE EXCHANGE IN CITRUS
FRUITS J. J. Gaffney, U.S. Department
of Agriculture, SEA, AR, Gainesville.
There are a number of instances where knowledge
of the mechanisms of heat and moisture exchange between
citrus fruits and the surrounding environment is
important. Examples include pre-cooling or cold storage
for maintenance of quality, heating during degreening,
heating in not water for color-adding, intermittent warming
and cooling for reduction of chilling injury, surface
moisture drying, and grove heating for prevention of
freeze damage. We have developed a basic mathematical
method to analyze the rate of heat transfer to or from
citrus as it affects temperature response at different
locations in the fruit. Also, we can analyze rate of
evaporation of moisture from fruit or rate of conden-
sation of moisture on the fruit surface. The research
involves basic experimental work to measure the physical
and thermal properties of citrus which affect heat or
moisture exchange and experiments on heating, cooling,
drying, effect of wax coating on moisture loss, etc.,
to confirm the results of the mathematical analysis.
Results can be used to modify current practices or
develop new techniques for improved process efficiency,
reduced energy use, and better maintenance of product
CONTROLLING PACKED BAG WEIGHT Earl
K. Bowman, U.S. Department of Agriculture,
SEA, AR, Gainesville.
Bag weights vary when packing either by machine
or manual methods. Trimming down average bag weight
to maximize profit while guarding against shipment
of underweight bags is a continuing challenge in
citrus packing operations. Controlling bag weight
by checkweighing samples of filled bags and adjusting
the sizer to alter fruit weight was studied last
season. The effectiveness of checkweighing varied
with fruit size and attention and judgement of the
personnel involved, Data obtained were also used in
calculations to explore use of a procedure involving
"bell curve" relationships for better controlling
bag weight. An in-line scale with automatic under
and overweight reject mechanism would reject any
underweight bags and permit a high degree of control
of average bag weight,
This program is published at a cost
of $280.00 or 47 cents per copy to
inform growers, packers and others
of applied research in harvesting,
fresh fruit handling and marketing.