sletter No. 46
May 26, 1972
Un. Of fo0abr: W. F. Wardowski
UniV. o g and Handling Section
University of Florida
Agricultural Research and Education Center
P. O. Box 1088
Lake Alfred, Florida 33850
UNIVERSITY OF FLORIDA INSTITUTE OF FOOD AND AGRICULTURAL SCIENCES
STATE OF FLORIDA, DEPARTMENT OF CITRUS
*Anyone wishing to receive this newsletter
may send a dozen stamped, preaddressed
envelopes to the above address.
Newsletter No. 46 CS-1972-14
May 26, 1972
1000-WFW-Lake Alfred, Florida 33850
Harvesting and Handling Section
BLACK ROT IN STORAGE FRUIT
Decay of citrus fruit caused by black rot (Alternaria citri) is not fre-
quently seen in Florida. Experimentally, it has been observed after a storage
period of three weeks at 700F. 'Valencia' oranges held in cold storage for
summer sale have been observed to develop a high percentage of black rot. This
is a rather insidious type of decay that usually develops inside the fruit,
without external symptoms.
This season we have observed an unusually high amount of black rot in
mandarin-type citrus fruit. Since high temperatures favor the growth of this
fungus, we assume the warm weather during the past winter influenced the increase
of black rot. If you are storing 'Valencias' this year, we recommend that after
the fruit have been held in cold storage for 6 to 8 weeks that one carton be
taken out of storage each week for internal inspection. Each fruit should be
cut in half along the stem to blossom-end axis.
Black rot in its very early stages of development is not easily detected
as it exists as a slight grayish discoloration near or on the seeds. As the
decay develops further, it becomes black and spreads into the pulp. Sodium
o-phenylphenate (Dowicide A) when applied as recommended (see Packinghouse
Newsletter No. 15, June, 1968) gives some control of black rot. TBZ or Benlate
do not control black rot.
G. E. Brown
A. A. McCornack
Florida Department of Citrus
PACKINGHOUSE MACHINERY SEQUENCE
Several shippers commented in a recent meeting that the custom of locating
fruit stamping machines prior to grading contributed to their problems in
meeting regulations requiring labeling of 40 or 50% of the fruit shipped. This
is because eliminations going to the cannery and amounting to an average of
about 40% of the crop were also being stamped.
The same principle applies, as has been pointed out many times, to any
treatment following washing including color-add treatment, drying, fungicide
application, waxing, and stamping. Grading following washing not only reduces
total costs by not putting expensive treatments on cannery fruit, but also
makes more efficient use of equipment by reducing crowding on the line.
AREC, Lake Alfred
Newsletter No. 46
ELEVENTH ANNUAL CITRUS PACKINGHOUSE DAY, SEPTEMBER 27, 1972
Wednesday, September 27, 1972, is the date for the Eleventh Annual Citrus.
Packinghouse Day at the Agricultural Research and Education Center, Lake
Alfred. Reserve this date on your calendar and plan to share some of the greatest
.concentration of postharvest citrus knowledge under one roof this year.
Available from Dr. W. Wardowski, Harvesting & Handling Section, Agricultural
Research and Education Center, P. O. Box 1088, Lake Alfred, Florida 33850.
"Agricultural Chemicals and the Citrus Industry" by W. F. Wardowski, R. Bullock,
and W. Grierson. Citrus & Vegetable Magazine 35(8):26,27,29,31. April, 1972.
"Florida Citrus Oils" by J. W. Kesterson, R. Hendrickson, and R. J. Braddock.
IFAS Bulletin 749. December, 1971.
"Postharvest Decays of Florida Citrus Fruits and Their Control" by CG Eldon Brown.
Proc. Pest Control Conf. Vol. 6, Univ. of Fla., 1972.
"Market Diseases & Blemishes of Florida Citrus Fruits" by A. A. McCornack and
G. E. Brown. Florida Departnient of Citrus. A valuable aid for identification of
12 diseases and blemishes including colored photographs.
Available from Miss Marie J. Ferree. Area Home Economist, Consumer Marketing,
337 University Hall, 2200 University Avenue, Berkeley, California 94720.
"The Consumer Revolt" by Marie Ferree, Produce Packaging & Marketing Association
Available from Mixing Equipment Co., Inc., 170 Mt. Read Blvd., Rochester, N. Y. 14603.
A bulletin on waste and water treatment including mixing applications and
mechanical aeration. 16 pages.
Available from Produce Marketing Assoc., Inc., P. O. Box 674, Newark, Delaware 19711.
"PMA Marketing Recommendations" with examples for labeling of produce containers,
Available from Agricultural Publications, University Hall, University of California,
Berkeley, California 94720.
"Operational and Economic Comparison of Forklift and Trailer Palletbin Systems
with the Field-Box System in Lemon Harvesting. Bull. 857.
Available from USDA/TFRD, 102 Agricultural Engineering Building, University of
Florida, Gainesville, Florida 32601.
"Reflectance Properties of Citrus Fruits" by J. J. Gaffney, Paper No. 71-811.
Amer. Soc. of Agr. Eng. 1971. A technical paper giving reflectance curves for
citrus with and without grade lowering defects.
May 26, 1972 0