OCT 1 1371
I extend to you a cordial welcome to the Agricultural
Search and Education Center at Lake Alfred. Last year, I
icomed you to the same organization but under the name of
;itrus Experiment Station." This organization had the name
;itrus Experiment Station" for over 50 years. Under the
.w name, it has the same people and the same programs
sentially that were here last year. What, then, is the
gnificance of the new name?
In the short term, the change in name has very little
[gnificance. We continue to play the same role and assume
e same responsibilities as in the past. In the long-run,
ever, it reflects a change in organizational structure
thin the University of Florida Institute of Food and Agri-
ltural Sciences which is intended to bring stronger, more
Effective support to agriculture on a state-wide basis
rough the many roles that the Institute of Food and Agri-
itural Sciences (IFAS) plays. The name change reflects
ie existence of changes already brought about in the last
Lve years--changes that have placed the Lake Alfred faculty
i closer working relationship with others in the IFAS
-ganization, changes that have brought Extension Specialists
the Lake Alfred station, and more active participation in
ricultural teaching programs. It also lays the ground-
Drk for additional changes in the future.
The citrus industry certainly is familiar with change.
ae IFAS organization does not believe that the best inter-
sts of Florida agriculture can be served by continuing to
3 forever the same things that have been done in the past.
ir name change reflects our intention to take on new programs,
Lve up old ones, and to keep up with the realities of the
ranging status of agriculture in Florida and in the United
We hope thatyou will enjoy today's program and that
au will come back frequently throughout the year.
Herman J. Reitz, Dire r
Agricultural Research and
Both Department of Citrus and University of Florida
scientists have continued the study of TBZ, Benlate, and
other new fungicides. Our abscission research program has
operated at high speed for another year as fruit loosening
remains a top priority objective. The mechanical harvest!
team spent most of its time this season facilitating the
use of harvesters developed in past years, but plans to
study some new systems in the months ahead. The search
for new chemicals capable of regulating acidity goes on.
If there are topics of concern to you not covered on
today's program, please feel free to contact the staff.
They will be happy to help.
John A. Attaway
Scientific Research Director
State of Florida, Department
University of Florida
Agricultural Research and Education Center
Lake Alfred, Florida 33850
Wednesday, September 8, 1971
8:30 A.M. Registration
9:30 A.M. WELCOME
Herman J. Reitz,
Horticulturist and Head
Agricultural Research and Education Center
John A. Attaway,
Director of Scientific Research
State of Florida, Department of Citrus
9:50 A.M. LABOR
A) THE CITRUS BAGMAN Henry F. Swanson,
Orange County Extension Director, Orlando.
Why should a public official get involved in such a
highly emotional and controversial topic as that of picking
labor. Because, by profession, Extension Agents are
"peddlers of information." So when news media personnel,
and others outside the industry, clamor for such information,
it is incumbent for someone or some agency to try to fill
this informational void. So I volunteered and rushed in
where some feared to tread. Seriously, I hope that by
delineating the problem into a better perspective, it might
be a contribution toward solving some of the problems, even
if it is only in the public information field'
B) HARVESTING LABOR AND REALISM Roy V.
Knowles, Golden Gem Growers, Umatilla.
Since there are not enough good pickers, we use a
lot of the other kind. This other kind becomes a complex
individual when viewed through the eyes of the field
foreman, the grower, the Federal Government, and Do-Good
Groups. The packinghouse operation is also viewed in a
rather interesting way by field crews. The entire harvest'
operation is really on a tightrope between our aims and
10:10 A.M. ABSCISSION
A) THE SEARCH FOR BETTER ABSCISSION AGENTS -
Bill Wilson, Assistant Professor, Florida
Department of Citrus, Lake Alfred.
At the present time, we have a very good abscission
agent (cycloheximide or Acti-Aid) for early and midseason
processing oranges, but nothing acceptable for 'Valencia'
oranges or the various fresh fruit varieties.
An expanded program of screening chemicals for poten-
tial abscission agents has been underway for several years.
This season over 3,000 individual tests were made, and a
number of chemicals worthy of further testing were found,
including-some of fresh fruit potential. Expanded testing
will continue again next season, especially with some of
the compounds noted this season.
B) THE PHYSIOLOGY OF ABSCISSION CHEMICALS
IN RELATION TO CITRUS FRUIT HARVEST -
Bill Cooper, CRD/USDA, Orlando.
The use of abscission chemicals to loosen fruit as
an aid to mechanical or manual harvest is now on the verge
of reality for citrus fruit destined for the juice processit
industry. All satisfactory abscission agents, including
cycloheximide, cause physical injury to the rind, which is
undesirable for fresh fruit marketing, but inconsequential
for the juice processing industry. This places the fruit-
loosening process in the category of a wound reaction.
Ethylene generation due to wounding of the rind, whether
induced by chemicals such as cycloheximide or by mechanical
wounding, acts as a triggering agent of an essential enzymatic
abscission process in the abscission zone of the button.
10:30 A.M. DECAY CONTROL
A) DECAY CONTROL WITH GROVE APPLICATIONS OF
BENLATE G. Eldon Brown, Associate Professor,
Florida Department of Citrus, Lake Alfred.
Evidence was obtained during this past season that
grove applications of Benlate could be expected to exhibit
antisporulant or eradicant activity against the stem-end
rot fungi. Sporulation of Phomopsis and Diplodia from the
deadwood was reduced, especially where trees had received
annual applications of Benlate for two years. Pinolene, an
antitranspirant applied to improve peel quality, slightly
improved the activity of Benlate. Regular annual applica-
tions of Benlate, if and when cleared for citrus, could
reduce postharvest stem-end rot even though these sprays
were made to the trees for control of other fungal grove
B) STATUS OF TBZ AND BENLATE Andy McCornack,
Associate Professor, Florida Department of
Citrus, Lake Alfred.
Thiabendazole (TBZ) was used during the past season by
nearly half of the 84 packinghouses that packed 200,000
cartons (4/5 bu.) or more during the 1969-70 season. More
packinghouses are planning to use this fungicide during the
coming season. There have been no changes in the recommen-
dations for the use of TBZ (see Packinghouse Newsletter No.
A one-year temporary tolerance (March 21, 1971-72) for
a maximum TBZ residue of 6 ppm has been approved by the
Environmental Protection Agency for California and Arizona.
Experimental shipments will be made with western citrus to
test the value of this higher tolerance. This study may
result in a change in the TBZ residue tolerance in the
United States from the.presently approved 2 ppm to 6 ppm.
A maximum TBZ residue of 6 ppm is now approved by many
citrus importing countries.
Temporary residue tolerances for Benlate have been
approved for a number of fruit crops. A temporary tolerant
for the use of Benlate on citrus fruit is a possibility
after the first of the year.
C) RESIDUE ANALYSIS AND STATUS OF TBZ FOR
CITRUS Fred Hayward, Associate Professor
Agricultural Research and Education Center
Analyses have shown that residues of thiabendazole
(TBZ) in citrus fruits generally meet the minimum 0.1 ppm
required by Florida regulations and are well below the
maximum legal tolerance of 2.0 ppm permitted by the Food
and Drug Administration. Application of TBZ by non-recove
spray methods tended to give residues at the lower levels
(0.1 0.3 ppm) while dips and emulsion wax sprays usually
gave somewhat higher residues (0.3 0.6 ppm). The only
samples which exceeded the legal tolerance resulted from
heavy coatings of an emulsion wax containing a high concern
tration of TBZ. If the legal tolerance should be increase
to 6 ppm, as has been proposed, some difficulty might be
experienced with the non-recovery spray method in meeting
the minimum (5% of legal tolerance) required by the Florid
regulation as it is now written.
11:00 A.M. POLLUTION CONTROL
A) NOISE CONTROL Calvin Oliver, Professor,
University of Florida, Gainesville.
Regulations on the extent of exposure of plant person
to noise have been established by recent federal legisla-
tion. Preliminary noise level data taken in a citrus pack
house indicate that current federal standards are exceeded
in only a few localized areas of the plant. In order to
avoid the penalties associated with violation of federal
regulations, it is recommended that:
(1) Plant noise levels be monitored (measurement)
(2) Excessive noise exposure be corrected (control)
(3) Guidelines be drawn up to avert future noise
B) WHAT MUST PACKINGHOUSES DO TO COMPLY WITH
FLORIDA'S WATER QUALITY STANDARDS AND
POLLUTION REGULATIONS Gene McNeill,
Florida Department of Pollution Control,
In the past, citrus packinghouse wastes have been
considered by pollution control agencies to be clean enough
so as to not require treatment prior to discharge into state
waters. Existing water quality standards and regulations do
require treatment of waste water from packinghouses before
permit for discharge can be granted. However, several alter-
natives exist whereby installation of an expensive treatment
facility will not be required. These alternatives include
spray irrigation, evapo-seepage ponds, and discharge into a
municipal sanitary sewer.
C) ONE SYSTEM OF ACCEPTABLE WATER POLLUTION
CONTROL Will Wardowski, Assistant Professor,
Extension Service, Agricultural Research and
Education Center, Lake Alfred.
Last February, Hi-Acres Concentrate, Inc., Orlando,
were given ten days notice to stop dumping their wastes
into public water. This included wastes from a packinghouse,
shop, concentrate plant, and feed mill. The existing "waste
disposal system" had developed over the years and was simply
a maze of underground drains leading to the stream. There
were no records of the drains, and many of their paths could
not be recalled or traced. Hi-Acres is justifiably proud
of the system designed and built by Rhett Ravenel, Grovi-
gation, Inc., Orlando. This controlled the pollution to the
satisfaction of the Pollution Control Agency within the 10-
day limit and never closed down their operation--a seemingly
impossible task. Non-polluted water, such as that used for
cooling, continues to flow into a nearby stream. A series of
large pits were dug to collect the rest of the water, which
is pumped (2 pumps per pit) through trash pumps with cutter
teeth. Solid wastes, removed by a DSM screen, go to the
feed mill. Liquid wastes are diluted until they can be
pumped on citrus groves through overhead irrigation. The
job is far from complete. Refinements and improvements
were installed during the summer shutdown and additional
equipment such as 2 waste heat evaporators are being
D) IMPROVED TRASH ELIMINATION Bill Grierson,
Professor, Agricultural Research and Educa-
tion Center, Lake Alfred.
Trash elimination is becoming a major problem in fresh
fruit packinghouses because of the decline in the quality o
manual picking. Developments in mechanical picking may wel
make the situation even more acute. Moreover, dirt, dust,
scales, leaf, and twig fragments, etc. are principal offen-
ders in raising the BOD (Biological Oxygen Demand) of
packinghouse wash water, to levels unacceptable under the
Florida Air and Water Pollution Control Act.
New packinghouse designs should include far more pro-
vision for early removal of trash than has been customary
in the past; and where possible, existing packinghouses
should consider improving trash elimination arrangements.
The basic roller conveyor is no longer enough, and we
suggest two additional devices. One of these has long been
used in 2 Florida packinghouses. This is a "vacuum brusher'
in which air is drawn down through slowly revolving (not
over 100 rpm) horsehair-grade brushes to remove sand and
similar adhering particulate matter. The second device is
one with which we are experimenting in our packinghouse.
This is a sloping belt trash eliminator designed to allow
the fruit to roll over it while carrying trash sideways off
the line. All such devices should be designed to deposit
leaves and trash into containers that can be handled by
lift truck operators with a minimum of manual work required
In addition, it is suggested that shears prior to the washer
be made self-cleaning.
11:40 A.M. L U N C H Equipment Demonstrations:
(1) New Degreening Rooms, Doug Deason,
(2) Sloping Belt Trash Eliminator, Bert
Robertsbn, Lake Alfred.
(3) Pop-Out Side Pallet Boxes, John Petersen,
(4) USDA Prototype Rope Stock Bagger, Earl
(5) Ag-Pak Automatic Citrus Bagger, Ted Baum,
Gasport, New York.
(6) Burford Bagger, Pak-It Mfg. Co., Red
Campbell, Atlanta, Georgia.
---- -- -- -- --------- --------- --- -- --- -- -- --- -- --
1:00 P.M. DEGREENING
A) EFFECT OF WASHING FRUIT ON DEGREENING -
Bill Grierson, Professor, Agricultural
Research and Education Center, Lake Alfred.
There has been considerable interest in recently
published results in which it was found that washing ahead
of degreening decreased decay of certain specialty fruits,
such as 'Robinson' tangerines. This is a development which
we are following with great interest. We have no recommen-
dation ourselves on decay control aspects of washing ahead
of degreening at present. We have, however, considerable
experience in washing oranges and grapefruit prior to
degreening and know that this must be approached with cau-
tion. In unpublished experiments in 1954-55 using 'Duncan'
grapefruit and 'Hamlin' and 'Valencia' oranges, fruit
washed ahead of degreening took about 25% longer to degree.
In 1955-56, this work was continued with 'Duncan', 'Marsh',
'Ruby Red', and 'Foster Pink' grapefruit and 'Hamlin' and
'Parson Brown' oranges. In 39 out of 44 individual experi-
ments, washing slowed up degreening; in 3 experiments there
was no difference; and in 2 the effect was reversed. The
average percentage increases in degreening time were: 'Duncan'
42%; 'Marsh', 23%; 'Ruby Red', 31%; 'Foster Pink', 28%;
'Hamlin', 13%; 'Parson Brown', 17%. The average over-all
increase in degreening time was 27%. Occasional experiment
in recent years have involved control samples washed ahead
of degreening and usually, either rate of degreening or
final color, or both, are affected. Only when oranges
and grapefruit have a considerable natural color break
can they be washed ahead of degreening without affecting
degreening time, packout, or both.
B) ETHYLENE INCREASES DECAY Andy McCornack,
Associate Professor, Florida Department
of Citrus, Lake Alfred.
Ethylene diffuses so rapidly that at times the concen-
tration of this material may be as high in degreening rooms
where the ethylene has been shut off as in degreening rooms
which are in operation. Decay of citrus fruit is increased
by ethylene so it is important to know when ethylene is
present in a packinghouse. Measuring the concentration of
ethylene is usually done by counting bubbles or with a flow
meter. Neither method tells the degreening room operator t
concentration of ethylene. A comparatively inexpensive
ethylene analyzer is now available to check the ethylene
Experimental work during the past season compared deca
losses of randomized samples degreened with 2 or 3 levels o
ethylene, and nondegreened fruit. In most instances, as th
concentration of ethylene increased, so did the percentage
decay. The decay increase was due to stem-end rot, not
Recommended degreening room conditions are: 1)
Temperature at 820 to 850 F, 2) Relative humidity 88 to 96%
3) Air movement in all parts of the room, 4) Continuous
additions of fresh air up to one complete air change per ho
and 5) An ethylene concentration of not more than 5 ppm.
C) INFLUENCE OF HUMIDITY ON HEALING OF INJURIES!
TO ORANGES G. Eldon Brown Associate
Professor, Florida Department of Citrus,
Injuries to citrus fruits increase the occurrence of
postharvest decays, particularly green mold and sour rot,
both of which require such injuries to the peel for penetra-
tion. Rapid healing of injuries retards development of these
decays and thereby considerably supplementing the benefits
from postharvest fungicides. Humidity has been found to
have a significant effect on the healing process. Healing,
or suberization, of injuries to the flavedo (outer peel)
of 'Pineapple' and 'Valencia' oranges and 'Marsh' grapefruit
was noted within 36 hours when the fruit were maintained at
100% relative humidity. Even after 5 days, only slight suber-
ization occurred to injuries of fruit held at 25-50% relative
humidity. Suberized injuries were less susceptible to
infection by green mold than were unsuberized injuries.
These observations give added support to our recommendation
that fruit be held at a high humidity between picking and
waxing to reduce not only peel injuries but also postharvest
D) EQUIPMENT REQUIREMENTS FOR DEGREENING ROOMS -
Doug Deason, Assistant Professor, Agricultural
Research and Education Center, Lake Alfred.
With the move toward building larger capacity degreening
rooms, maintaining proper conditions becomes even more
critical. Present recommendations for heating capacity,
air flow rate, ventilation rate, and ethylene rate will be
reviewed. The types and proper location of sensing elements
for automatic control of temperature and humidity are to be
re-emphasized. Differences in sensor location for refriger-
ated storage will be pointed out. Alternative types of
equipment used for heating and humidifying of degreening
rooms will be discussed. We can now recommend continuous
operation of degreening rooms rather than the traditional
"batch type operation."
E) HORIZONTAL VS. VERTICAL AIR MOVEMENT -
Roy Schick, Jr., SEFCO-Blue Goose, Vero
Being one of the few packinghouses that has both hori-
zontal flow and vertical air flow degreening rooms, I would
like to stage briefly that we get tremendously more uniform
degreening with the horizontal flow system, as opposed to
the traditional system.
The problem is obviously lack of air circulation at t
corners of the "chimney type" room. What do we do about i
Many times we have reloaded the three stacks from each
corner of our "chimney type" room for additional degreenin
We have observed this difference in efficiency with
grapefruit harvested on the same say, from the same grove,
under uniform cultural.practices. We have compared these
two types of rooms for three years and feel we know.what
we are talking about.
We wish we had only horizontal air flow degreening
rooms. Bill Grierson who originated this type of room quo
Christopher Columbus who in 1491 said, "The shortest dista
is a straight line." It is still a sound principle.
F) A NEW LOOK AT ETHYLENE AND COLOR -
Ivan Stewart, Professor, Agricultural
Research and Education Center, Lake Alfred
For many years, it has generally been accepted that
carotenoids (certain color pigments) in the peel show no
significant changes as a result of ethylene treatment.
However, by the use of new techniques developed for the
purpose of studying the individual pigments in the peel we
have been able to increase substantially the color of some
cultivars by use of ethylene. All fruit studied Showed so
increase in color, but those of the reticulata (common man
darins) group gave the greatest response. Conditions
normally used for degreening are not favorable for increase
2:00 P.M. PACKAGING
A) A STEP TOWARD THE DEVELOPMENT OF A
BETTER EXPORT CITRUS CARTON Phil Hale,
TFRD, USDA, Orlando.
In an effort to improve the arrival condition of Flori
grapefruit in overseas markets, seven shipments were made
evaluating six types of experimental conventional-size car-
tons manufactured from heavier boardweights and/or moisture
resistant materials. In testing for bottom sag, side, and
end bulge, and compression strength, the two types of wax-
dipped cartons performed favorably. Differences in product
damage, however,.were too small to be attributed to the
types of cartons studied. The most significant informa-
tion was the extremely high amount of misshapened fruit
found in all cartons, regardless of type, ranging from
68.4 to 71.6%. The data indicate that to improve arrival
condition of Florida grapefruit in overseas markets, (1)
pack the cartons with minimum top-to-bottom, side-to-side,
and end-to-end bulge; and (2) use cartons with greater
compression strength and more moisture-resistant qualities.
B) PROPOSED CITRUS CONTAINER RESEARCH -
Larry Risse, TFRD, USDA, Orlando.
In an attempt to improve the arrival condition of
Florida citrus in domestic and overseas markets, a broad
research program will be initiated this year to develop an
improved citrus carton. Past data and receiver statements
indicate that stronger conventional-size cartons do not
substantially improve the arrival condition. A number of
stronger and various size cartons will be developed,
laboratory tested, and the most promising ones commercially
tested in an attempt to develop a better carton for Florida
citrus. The citrus industry is cordially invited to parti-
cipate in planning and conducting this study.
C) PERISHABLES HANDLING CONFERENCE Stan
Rosenberger, Extension Service, University
of Florida, Gainesville.
A national conference entitled, "Delivering Quality
Perishables--Streamlining Team Efforts in the '70's", will
be held on the University of Florida campus, Gainesville,
January 9-11, 1972. Perishables in this conference will be
grouped under 4 categories: Fresh Fruits and Vegetables,
Fresh Meat and Poultry, Flowers and Foliage Plants, and
Frozen Foods. Speakers will be from both industry and
government, many of them coming from out of state. Strengths
and weaknesses of handling systems from the shipper to the
housewife will be discussed. Conference participants are
expected to be heavy to buyers, merchandisers, and transporters.
We hope that shippers will be represented both to keep up-
to-date themselves and to present their opinions to the
2:30 P.M. COOLING AND STORAGE
A) STORAGE OF FLORIDA CITRUS FRUITS Tim
Hatton, Jr., MQRD, ARS, USDA, Orlando.
Successful storage of Florida citrus can be accom-
plished by proper selection, fungicidal treatment, and
storage conditions. A relative humidity of 85 to 90% is
desirable for all citrus to prevent shriveling. In grape-
fruit, rind pitting and aging become serious problems at
low temperatures, especially around 400F. Florida grapefrt
picked before January will pit when stored at 500 but will
keep well at 600; however, 500 is a better storage temperate
from January through the remainder of the season. If proper
precautions are taken, such fruit can be stored for 8 weeks
without excessive spoilage. Oranges store best at 32-340
for up to 3 months provided the proper care is taken; e.g.,
careful harvesting and optimum maturity at storage time.
'Temples', tangerines, and tangelos store best at 38 to 40
for up to 4 weeks, and handling is extremely important espe
ially for tender types such as tangerines. A temperature
low as 320 is satisfactory for up to 2 weeks, although at
this temperature 'Temples' and 'Orlando' tangelos sometimes
develop chilling injury.
Our controlled-atmosphere storage research continues
without anything specific to recommend at this time. Empha
sis is being placed on long-term storage of grapefruit, anc
we have observed that fruit is more susceptible to CO2
injury as the season progresses. Long-range effects of
ethylene are also being studied.
B) BLACK ROT OF STORED CITRUS FRUITS John
J. Smoot, MQRD, ARS, USDA, Orlando.
Black rot, caused by Alternaria citri, affects all
kinds of citrus fruits but is seldom prevalent enough to ca
significant losses of freshly harvested fruit going directly
to market. It can be a serious decay, however, of fruits,
including 'Valencia' oranges, grapefruit, lemons, etc.,
stored for long periods of time. It usually appears as a
black core rot developing from the stem button and may not
be visible without cutting the fruit. It can also develop
from side injuries or stylar-end splits. Even slightly inf
ted fruits will have a decided off-flavor. It is not ade-
quately controlled by approved fungicides, although SOPP
(Dowicide) offers somewhat better control than TBZ.
Therefore, a combination fungicide treatment may be
advisable to combat citrus storage diseases. Black rot
is retarded but is not stopped by low temperature and will
develop slowly at 320F.
C) NEW FINDS ON PEEL DISORDERS Gene
Albrigo, Assistant Professor, Agricultural
Research and Education Center, Lake Alfred.
Three physiological peel disorders of Florida
oranges--stem-end rind breakdown, 'Pineapple' pitting, and
'Valencia' aging--appear to be ultimately expressions
of the daily water stress exerted on the peel in the grove
and the continued peel moisture loss after harvest. Water
loss studies and wax and stomata distribution data are
presented relating to peel moisture stress before and after
Meeting will be turned over to Cope Newbern, President,
Florida Fresh Citrus Shippers Association.
Business Meeting: Florida Fresh Citrus Shippers
Association. (This is a private meeting not open to the
Meeting of research workers (University of Florida;
Florida Department of Citrus; Florida Department of
Agriculture; Florida Department of Air and Water Pollution
Control; and U. S. Department of Agriculture) in the
Conference Room on the second floor of the Canning Plant.