Speaking for the Florida Citrus Commission and the Department
f Citrus, Scientific Research Staff I am delighted to welcome you
o our 18th Annual Packinghouse Day program. I think you will find
oday's presentations to be very pertinent to the problems of the
lorida fresh fruit industry and I hope you will join me in
extending sincere congratulations to Dr. Grierson, Dr. Wardowski
nd all the speakers for assembling such an interesting program.
Last year, the Export Committee of the Florida Citrus
ackers asked the Department of Citrus to designate one scientist
o be the industry's authority on pesticide residue restrictions
n each of the countries to which you export fresh citrus fruit.
hat man is Dr. Steven Nagy who will report to you on this assign-
ent for the first time this morning. From here on, Steve will
e the scientist to consult on residue problems overseas.
This is the one time each year when the experts from all
ur research agencies, USDA, University, and DOC are gathered
together under one roof, and I hope you will take advantage of
he opportunity to consult with our speakers during the course of
hn A. Attaway
Scientific Research Director
Florida Department of Citrus
Eighteenth Annual Citrus Packinghouse Day
University of Florida
Agricultural Research and Education Center
Lake Alfred, Florida 33850
Wednesday, September 5, 1979
9:00 A.M. Registration
9:40 A.M. WELCOME
Herman J. Reitz
Horticulturist and Director
Agricultural Research and Education Center
John A. Attaway
Director of Scientific Research
State of Florida, Department of Citrus
PRESIDING George McClure, Commissioner and Chairman,
MORNING Scientific and Harvesting Research Committee,
SESSION Florida Department of Citrus
10:00 A.M. THE 'SUNBURST' CITRUS HYBRID Jack Hearn, U.S.
Department of Agriculture, SEA, AR, Orlando.
The 'Sunburst' citrus hybrid was developed in the USDA
breeding program and released as a new cultivar in February
1979. 'Sunburst' fruit would be marketed from about mid-
November through mid-December. The fruit are larger, more
attractive, and their uniform size and maturity should result
in higher packout percentages, when compared with 'Robinson'
and 'Dancy.' The rind of 'Sunburst' fruit is usually fully
colored when the fruit is mature enough to harvest. This
would result in reduced packinghouse costs. The fruit are more
rable and should have less postharvest decay losses than that
S'Dancy' and 'Robinson.' 'Sunburst' fruit show less rind
jury from plugging if fruit is snapped rather than clipped
en compared with 'Dancy.' The trees are highly resistant
snow scale and they have field resistance to Alternaria
disease. The juice is highly colored and can be used for
lending in juice products.
0:10 A.M. FUNGICIDES FOR POSTHARVEST DECAY CONTROL Eldon
Brown, Florida Department of Citrus, Lake Alfred.
Decay is a major factor limiting the keeping quality of
lorida fresh citrus. Control can be difficult when fruit
re injured from rough handling and when prolonged transit
imes occur during export shipment. A continuing program
xists at Lake Alfred to develop improved fungicides and
methods of application. Research is progressing in the search
or new chemicals to combat decay fungi that have either
developed resistance or that never were effectively controlled
y the present fungicides. Imazalil, a new material which is
uite effective against mold, has been granted an experimental
permit for commercial application to a limited amount of
ruit this fall. Potassium sorbate, a water soluble food
reservative, is being evaluated for decay control, as are
their experimental materials. Results of some of these studies
ill be presented.
0:20 A.M. INTERNATIONAL PESTICIDE TOLERANCES Steve Nagy,
Florida Department of Citrus, Lake Alfred.
The Codex Alimentarius Commission (CAC) through the Food
and Agriculture Organization's World Health Organization (FAO/
WHO) has attempted to initiate a uniform procedure for the
establishment of pesticide tolerances on imported citrus
fruit. A lack of rule uniformity by citrus-importing countries
on the subject of surface treatment of fruit has been a major
obstacle confronting FAO/WHO Pesticide Residue Committees.
Postharvest pesticide tolerances have been established by most
countries importing Florida citrus but data from the same
importing countries on preharvest pesticide tolerances is scarce.
CAC has proposed standard tolerance limits for 43 preharvest and
3 postharvest pesticides used on citrus fruit. Although many
countries importing Florida citrus accept CAC's pesticide
tolerance recommendations, some do not.
10:30 A.M. OCCASIONAL EXCESSIVE BIPHENYL RESIDUES IN
GRAPEFRUIT John Smoot and Paul Davis, U.
S. Department of Agriculture, SEA, AR,
Orlando, and Steven Nagy, Department of
Citrus, Lake Alfred.
Biphenyl residues in excess of the Japanese and Europea
70 ppm tolerance level were reported on a number of occasion
in grapefruit exported to Japan in the early 1977-78 season,
and on one occasion this past season. Less frequently,
excessive residues have been reported in Europe. We have foi
that biphenyl absorption is related to fruit maturity. Also,
absorption increases with duration of exposure and temperature
of holding. Ventilation of the fruit or removal of the pads
did not remove biphenyl already absorbed. Restricted
ventilation after packing, during simulated shipping and
storage resulted in higher residues than fruit receiving norn
air exchange, but both USDA and IFAS/FDOC research confirm
the finding that excessive absorption of diphc~iyl by very
early season fruit is the principal factor.
10:40 A.M. HEALING OF INJURIES IN CITRUS FRUIT: THE
ROLE OF PHENOLICS IN RESISTANCE TO DECAY -
Mohamed Ismail and Eldon Brown, Florida
Department of Citrus, Lake Alfred.
Injuries to flavedo tissue of citrus fruit initiate
healing within 12 hours and are usually healed by 48 hours,
when held at 86F and 96-98% relative humidity. This
healing is manifested by increased free phenolics, enzyme
activity, formation of lignin and consequent resistance to
infection by Penicillium digitatum (green mold). Phenolic
extracts from citrus flavedo retard the growth of germinated
green mold spores. Greater inhibition was observed with
extracts of green, immature fruit, collected in September,
than with extracts of mature or ripe fruit collected in
November and January. Fungal inhibition was also obtained
by phenolic extracts from healed injuries of 'Valencia'
10:50 A.M. HOST-PATHOGEN INTERACTIONS Charles
Barmore, Agricultural Research and
Education Center and Eldon Brown,
Florida Department of Citrus, Lake Alfred.
Shallow injuries in the peel of citrus fruit occurring
after ethylene treatment are less susceptible to green mold
caused by Penicillium digitatum than are injuries occurring
before ethylene treatment. Ethylene induced resistance
appears to be related to the rate of lignin formation, and
not just the amount of lignin formed. The rate of lignin
formation in peel injured following ethylene treatment is 2
to 2.5 fold greater than in peel injured prior to ethylene
treatment. This association might also be involved in the
observed resistance of 'Robinson' tangerines to anthracnose
when treated with Ethrel prior to harvest.
11:00 A.M. RESISTANCE TO CHILLING INJURY OF GRAPEFRUIT -
Al Purvis, Kaz Kawada and Bill Grierson,
Agricultural Research and Education Center,
Resistance of grapefruit to chilling injury (CI) can
occur naturally or can be induced by various postharvest
conditioning treatments. Periods of natural resistance
usually occur during mid-season when growth processes of
the tree are minimal. Resistance is also affected by the
time of day the grapefruit is picked. Recent studies show
that grapefruit picked during mid-afternoon are about twice
as resistant to CI as grapefruit picked during early and mid-
morning. Grapefruit stored immediately is more susceptible
to CI than if it has a one-to-several days "conditioning
period" prior to storage.
The mechanisms of seasonal, diurnal, and induced
resistance to CI are not known. Over the past two seasons,
we have observed high levels of both reducing sugars and the
phytohormone, abscisic acid, in the peel of grapefruit
during the period of greatest seasonal resistance to CI.
The role that these constituents play in inducing resistance
is speculative. Perhaps more than one mechanism is involved
in the resistance of grapefruit to CI.
11:10 A,M. ANALYSIS OF CITRUS DRYER PERFORMANCE Jerry
Gaffney, U.S. Department of Agriculture,
SEA, AR, Gainesville.
The rate of moisture removal from the surface of citrus
fruits in forced air circulation, roller conveyor type
dryers is related to several factors. These include
fruit size, fruit temperature prior to drying, and temperature
humidity and flow rate of the drying air. A mathematical
analysis has been developed to study the relationships
between these variables as they affect dryer performance
and efficiency. These have yielded information useful
in the design of simple dryer control systems and
modifications to existing drying techniques which can
provide potential substantial savings in fuel costs.
11:20 A.M. DRYING FRESH CITRUS WITH DEHUMIDIFIED AIR -
Bill Miller, Agricultural Research and
Education Center, Lake Alfred.
Drying surface moisture from fruits and vegetables
is a major operation in our packinghouses. Conventional
practice now consists of heating air via steam radiators
or natural gas dryers. As an alternative, solid desiccants
can create a sufficient humidity ratio difference (HRD)
to accomplish surface drying in a comparable time with
lower maximum temperatures, an important factor for temp-
erature-sensitive commodities or varieties. Additionally,
some desiccants can be appreciably regenerated at temper-
atures of 100'C or less, achievable with flat-plate solar
A pilot plant citrus dryer was fabricated to utilize
solid desiccants for surface moisture drying. An in-line
duct blower circulated air through 5.1 cm desiccant filters
and across fruit transported on a roller conveyor.
Desiccant storage and an auger system to dispense spent
desiccant were incorporated into the system. Maximum
drying potential expressed as HRD was 0.013 kg/kg for
silica gel and 0.000 kg/kg for activated alumina.
1:30 A.M. FLORIDA CITRUS PACKERS ENERGY SURVEY -
Will Wardowski, Extension Service, Bill
Miller, Agricultural Research and Education
Center, Lake Alfred, and 44 Florida
A survey of energy consumption was undertaken in April
979 from packers responsible for over 50% of the commercial
resh citrus fruit packed in Florida during the 1977-78
eason. Energy efficiency comparisons were made on the
asis of energy used per packed 4/5 bu. carton. Energy
consumption ranged from 0.1018 to 1.2985 KW electricity,
.0155 to 0.0867 gal fuel oil, 1.5333 to 6.8573 cu ft
natural gas, 0.0032 to 0.0100 gal lift truck propane or
.0028 to 0.0123 gal lift truck gasoline. Additionally,
0.0 to 276.1 thousand cartons were handled per lift truck
n a season. Each packer who participated in this survey
ill be supplied with a summary of the survey information,
nd specific data from his own operation so that he may
ompare energy consumption in his packinghouse with others
f similar size.
11:40 A.M. THE CITRUS INDUSTRY SHARE PROGRAM AT LAKE
ALFRED Herman J. Reitz, Director,
Agricultural Research and Education Center,
The Lake Alfred Center has a serious problem with
building space. This problem developed from increases in
IFAS activity (for example, the addition of 6 professional
Extension Service Specialists), increased Department of
Citrus activity (for example, the expanded Harvesting
Research and Development program), the deterioration
of older buildings (for example, the 1927 Production
Building), and IFAS plans to increase activity here
not only in research, but also in extension and
An industry committee is attempting to solve part
of this problem through a campaign for private
subscriptions. This campaign is being run through SHARE
(Special Help for Agricultural Research and Education),
the agricultural portion of the University of Florida
Foundation. Contributions to SHARE are tax-deductible
and can be ear-marked 100% for the Lake Alfred Building
Fund. The suggested contribution is a penny a box for
each grower's production over a 3-year period. The
goal is $1,500,000. Pledge cards are available.
The 1979 Legislature has also appropriated $1,500,000
for new construction at Lake Alfred, partly in recognition
of the private subscription effort.
The private effort, plus the matching funds from the
Legislature, will solve the Center's space problem, and
will for the first time provide citrus people a research
facility they can be proud of and worthy of the industry's
11:50 A.M. EQUIPMENT DEMONSTRATIONS & ANNOUNCEMENTS -
Bill Miller, Agricultural Research and
Education Center and Will Wardowski,
Extension Service, Lake Alfred.
NOON L U N C H Equipment Demonstrations:
(1) ABS-type Rollers Fred Osborne, Gulf
Atlantic Pump & Supply Co., Lakeland, FL.
(2) Desiccant-type Dryer W. M. Miller,
Agricultural Research & Education Center,
Lake Alfred, FL.
(3) Magnetic Broom Jim Ellis, Lake Garfield
Citrus Coop., Bartow, FL.
(4) Oil Separator (Automatic Grease
Interceptor) Bob Waldeck, Baker Waldeck
Associates, Montville, NJ.
(5) Pallet Boxes Alex Jonson, Product Manager
Midland-Ross, Cincinnati, OH.
(6) Straddle-Fork Lift Bill Davis, Marketing
Manager, Ag Automation, Oxnard, CA.
Due to the early printing of this program, certain exhibitors
may not appear in the above list. Any additional displays
will be announced before the lunch break.
PRESIDING Charles M. "Bud" Shinn, Jr., Commissioner and
AFTERNOON Chairman, Export Committee, Florida Department
SESSION of Citrus
1:30 P.M. PACKERS' CORNER Jim Ellis, Lake Garfield
Citrus Co-op., Bartow.
It has been three years since I appeared before this
group to present some ideas that have resulted in labor
savings or increased productivity. The following
innovations may provoke some new thinking among this group.
1. Magnetic Broom A permanent magnet is hung on
the rear of a fork lift. It picks up nails, staples, bolts,
etc. as the operator drives the lift truck around the yard.
This item does not draw unemployment or overtime. And EPA
please note, this item is pollution free. The cost is
about the price of one 10:00 x 20 tire.
2. Photo Eye, Electric Eye in Juice Bin As a juice
bin fills up with fruit, a photoelectric beam is broken
causing a bell to ring. The bell notifies the packing-
house manager that it is time to change the fruit to
another bin. If the electrical switch is not reset after
the bell rings for ten minutes, the switch will shut down
the packinghouse. This piece of equipment saves us from
paying an extra person for going to sleep in the juice
bin area while the bins fill up and run over.
3. Trash Collection With the addition of a sloped
cross belt in line with the fruit flow from the dumper,
we are able to deposit sand, leaves and limbs on a belt
going to a pallet bin. The bin is dumped into a dump
truck for disposal. We floored the slat chute under the
dumper with a metal sheet, again directing sand and leaves
onto the belt going to the pallet bin. This system has
helped us to put almost all trash into one central point.
We still have stems attached to the fruit, but maybe some
day we can resolve that.
4. Electric Switch Rinse water is turned off when
the machinery is turned off. This saves water and the cost
of electricity to pump more water.
1:40 P.M. BAGGING CITRUS--WEIGHT VARIABILITY Earl K.
Bowman, U.S. Department of Agriculture, SEA,
Automatic machines available for practical use cannot
turn out bags filled to the same exact weight, bag after
bag. Some variation is inescapable as we know intuitively.
Calculations based on studies of bagging operations show
that the average bag weight in machine-filling 5-pound bags
by the prevailing method must be maintained at about half
a pound above a minimum acceptable shipping-point weight
per bag. Generally, this means an average weight of at
least 5.75 pounds. Even then, according to normal curve
(bell-shaped) distribution relationships, about three
bags out of 1,000 (0.30%) likely would weigh less than
the specified minimum shipping-point weight. If any
conditions should cause more than a minimal portion of
under-count bags (containing less than set count on machine)
in the flow of packed bags, an average bag weight greater
than 5.75 pounds would be indicated by normal
1:50 P.M. PACKINGLINE MACHINERY Bill Grierson, Bill
Miller and Will Wardowski, Agricultural
Research and Education Center, Lake Alfred.
All packers should by now have a copy of Bulletin 803.
Additional copies are available for those who can use them.
In designing new packinghouses and remodeling old ones*
maximum use of the information in this bulletin can be had
by noting such points as:
Effect of length vs. width of line on size of building
and on plumbing and electrical costs;
Means of getting trash out quickly before it does
further damage to fruit and equipment;
Energy costs for roller-supported vs. pan-supported
Constructing turns to minimize fruit damage;
Effect of location of grading on capacity of the
Optimum use of graders with regard to size of
fruit and degree of blemish;
Adaptability to future mechanization.
We have been pleased with the acceptance of this
lletin, but must acknowledge the criticism that
formation is not given on operation of such processes
Waxing, color-adding, etc. In particular, occasional
lor-add problems can be avoided by:
Accurate calibration of the thermostat controlling
Use of pure ("potable") water, treated for hardness
Insurance in the form of an alarm thermometer to
"police" the thermostat.
Increasing use is being made of the conferences that
e put on at this Research Center for any packer contemplating
emodeling or building anew. Just contact any of the above
authors if you are interested.
:00 P.M. UPDATE ON FARM LABOR CONTRACTOR LITIGATION -
Clark M. Ghiselin, Executive Vice President-
Secretary, Citrus Industrial Council, Lakeland.
When a registered contractor fails to comply with the
arm Labor Contractor Registration Act and the contractor
annot be located what are the liabilities of the
erson who engaged that contractor's services? Such
problems are increasingly important to any organization
involved in citrus harvesting.
:10 P.M. PREHARVEST APPLICATION OF GROWTH REGULATORS
FOR BETTER QUALITY GRAPEFRUIT Mohamed
Ismail, Florida Department of Citrus, Lake
Preharvest sprays using a combination of low levels of
gibberillic acid and 2,4-D delay fruit senescence and reduce
late season fruit drop. Gibberellic acid may also delay
fading of the internal color of 'Ruby Red' grapefruit.
Timing of application is important. The effect of too early
applications (July-Sept.) diminishes early as the season
progresses, while too late applications (Dec.-Jan.) may
reduce flowering and hence, reduce the following year's
2:20 P.M. EXPORT GRAPEFRUIT SHIPPING TESTS PHYSIOLOGICAL
CHANGES L. G. Albrigo, Agricultural Research
and Education Center, Lake Alfred and P. W.
Hale and T. T. Hatton, U.S. Department of
Agriculture, SEA, AR, Orlando.
Field sprays of growth regulators and antitranspirants,
and double waxing treatments on 'Ruby Red' grapefruit were
evaluated for shipments to Japan in December and May.
Comparable lots were held locally. Weight loss, color, gloss
physiological disorders and softness were examined.
2:30 P.M. EXPORT PACKAGING AND PALLETIZING Philip
W. Hale, U.S. Department of Agriculture,
SEA, AR, Orlando.
In three shipping tests to Japan, grapefruit in
fiberboard cartons were stacked in five different palletizing
patterns and loaded on ships to determine the effect of
the stacking patterns on product temperature. In all tests,
the differences in the cooling rate of grapefruit were
slight between the five stacking patterns, and differences
found in deformation of fruit in cartons stacked in the
five palletizing patterns were negligible. Pallet stacks
arrived in satisfactory condition with the use of plastic
stretch netting and plastic strapping and with cartons
secured by cornerboards. Grapefruit exported in 1200-1b
capacity wooden bins showed up to five times more serious
deformation than fruit of similar quality unitized in 4/5
bushel cartons. Grapefruit packaged in experimental honey-
comb cartons, in shipping containers with laminated side
and end body panels, and in experimental 11 1/2-in. wide
cartons arrived in excellent condition. One type of
internal padding material reduced serious deformation to
fruit, but may not be economic.
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