INSTITUTE OF FOOD AND
UNIVERSITY OF FLORIDA
A Vegetable Crops Extension Publication
vegetable Crops Department 1255 HSDPP Gainesville, FL 32611 Telephone 392-2134
September 20, 1989
I. NOTES OF INTEREST
A. Purpose of the Vegetarian.
B. Vegetable Crops Calendar.
C. New Publications.
II COMMERCIAL VEGETABLES
A. Icebox Watermelon Varieties.
B. Delay in Ripening Initiation of Florida Green Tomatoes.
C. Evaluating Handling/Shipping Operations for Precooling.
III. PESTICIDE UPDATE
A. Mancozeb and Maneb Labels Have Been Dealt Lethal
Blows for Vegetables.
B. Tomato Transplants Withdrawn from B-Nine SP Label.
IV. HOME GARDENING
A. 1989 Vegetable Gardening Survey.
Note: Anyone is free to use the information in this newsletter.
Whenever possible, please give credit to the authors. The purpose of
trade names in this publication is solely for the purpose of providing
information and does not necessarily constitute a recommendation of
The Institute of Food and Agripultural Sciences is an Equal Employment Opportunity Affirmative Action Employer authorized to provide research,
educational information and other services only to individuals and institutions that function without regard to race, color, sex, or national origin.
COOPERATIVE EXTENSION WORK IN AGRICULTURE AND HOME ECONOMICS, STATE OF FLORIDA. IFAS, UNIVERSITY OF
FLORIDA. U. S. DEPARTMENT OF AGRICULTURE, AND BOARDS OF COUNTY COMMISSIONERS COOPERATING
I __ ~_
I. NOTES OF INTEREST
A. Purpose of the Vegetarian.
The Vegetarian is an excellent
newsletter. One of its primary aims is to
provide the latest, up-to-date, timely
information for county extension faculty
with responsibilities for commercial
and/or urban vegetable programs. We
would expect county faculty to serve as
the major information providers to the
clientele in the counties, of information
contained in the Vegetarian. Clientele
who want personal copies of Vegetarians
should contact their local extension office.
(App, Asst. Dean, Agricultural Programs,
October 27-30, 1989. National Junior
Horticultural Association Annual
Convention. Marriot's Hunt Valley Inn.
Hunt Valley, MD (Baltimore-Washington
October 31-November 2, 1989.
Florida State Horticulture Society Annual
Convention Hyatt Regency Tampa, FL.
November 14-15, 1989. Vegetable
Packinghouse Operations Meetings. An
evening seminar will be held in
Immokalee (Nov. 14) and Delray Beach
(Nov. 15) to discuss postharvest operations
in packinghouses, particularly reducing
mechanical injury during handling,
precooling and the potential use of
controlled atmospheres for domestic and
export shipping. (Contact Steve Dobbs,
Collier Co. or Ken Shuler, Palm Beach
November 28-29, 1989. Vegetable
Research Southern Collaborators'
Conference. Omni Hotel, Charleston, SC.
November 29-December 2, 1989.
Cucurbitaceae 89: Enhancement of
Cucurbit Germplasm. Omni Hotel,
C. New Publications (Vegetables)
Icebox Watermelon Variety Evalua-
tion, Spring 1989, by D. N. Maynard.
GCREC Res. Rept. BRA 1989-11.
Radicchio Variety Evaluations, Fall
1988 and Spring 1989 by D. N. Maynard.
GCREC Res. Rept. BRA 1989-13.
Plum Tomato Variety Evaluation,
Spring 1989 by D. N. Maynard. GCREC
Res. Rept. BRA 1989-15.
Seedless Watermelon Variety Eval-
uation, Spring 1989 by D. N. Maynard.
GCREC Res. Rept. BRA 1989-16.
II. COMMERCIAL VEGETABLES
A. Icebox Watermelon Varieties.
Icebox watermelons are small-fruited
types weighing between 6 and 12 lbs.
They have been available for some time,
but have never attained commercial
importance in the United States. 'New
Hampshire Midget' was introduced by the
New Hampshire Agricultural Experiment
Station in 1951. Although new in
concept, it failed to become commercially
acceptable because of susceptibility to
fusarium wilt, relatively weak rinds, large
and numerous seeds, and only fair quality.
'Sugar Baby', another icebox variety was
developed by M. Hardin of Geary, Okla-
homa and introduced by Woodside Seed
Co. in 1956. It has some of the same
shortcomings as 'New Hampshire Midget',
but has attained a fair degree of
popularity in various parts of the world
outside of the United States.
Although the number of icebox
watermelon varieties remain quite small
in comparison to large-fruited types, some
recently-introduced and soon-to-be re-
leased varieties offer promise for enhance-
ment of this segment of the watermelon
industry. Social and demographic changes
in the U.S. population favor production of
smaller size watermelons that are more
compatible with smaller household size.
Icebox watermelon variety trials have
been conducted over the past several
years at several locations in Florida.
Generally, 'Mickylee' and 'Minilee', deve-
loped by Dr. Crall at the Central Florida
Res. & Ed. Ctr., Leesburg, have produced
high yields and quality in these trials.
Ten icebox watermelon varieties were
evaluated in the spring of 1989 at the
Gulf Coast Research & Education Center
in Bradenton. Seeds were planted in 1.5
inch cell Todd planter flats on February 2
and the transplants were set in the field
on March 1. The watermelons were
harvested three times beginning on May
16 and ending on June 15.
Highest yields from the first harvest
were obtained from 'Southern Belle',
'Sugar Baby', 'Baby Fun', 'NVH 4319', and
'Baby Gray'. Total yields were highest
from 'Tiger Baby' (626cwt/A), 'Baby Fun',
'S86 C8-5' (CFREC-Leesburg), and 'SSDL'
(CFREC-Leesburg), but 'Baby Fun' fruit
weight was too great for it to be
considered a true icebox melon. Soluble
solids were the highest in 'S86 C8-5'
(13.1%), 'SSDL' (12.9%), and 'Baby Fun'
(12.6%). Observations on hollowheart
were made with every cell separation
noted. 'S86 C8-5', 'Minilee', 'SSDL',
'Tiger Baby', and 'Mickylee' had the
highest incidence of hollowheart. It
should be pointed out-that some of the
hollowheart was so slight that it would
not affect consumer acceptance.
Notations on internal quality
indicated that some fruit of 'NVH 4319',
'Southern Belle', and 'Sugar Baby' had
poor internal color, whereas flesh color of
'S86 C8-5' and 'SSDL' was outstanding.
One of the important characteristics
in icebox watermelons is uniform size for
convenient packing. 'Tiger Baby', 'S86
C8-5', 'Sugar Baby', 'Mickylee', 'NVH
4319', and 'Southern Belle' produced at
least 70% of fruit in the 6 to 12 pound
Based on the characteristics
measured in this trial, 'Tiger Baby', 'S86
C8-5', 'SSDL', and 'Mickylee' had the best
(Maynard, Vegetarian 89-09)
B. Delay in Ripening Initiation of
Florida Green Tomatoes.
Construction of special rooms for
ripening tomatoes with exogenous ethy-
lene began in Florida about 20 years ago.
Prior to that time some tomato ripening
initiation with exogenous ethylene had
taken place in existing rooms which had
been appropriately modified. Otherwise,
packed mature-green tomatoes were
shipped without exposure to ethylene.
Ten years ago all major packers of
Florida mature-green tomatoes had special
rooms for ripening initiation. A major
modification of these ripening rooms was
made to prevent the accumulation of
carbon dioxide which impeded the
ripening process. This new system
became known as the "flow-through"
system. Most mature-green tomatoes
packed in Florida passed through these
ripening initiation rooms.
An increasing number of packed
mature-green tomatoes are now being
shipped from Florida without exposure to
ethylene. Some of these tomatoes are
treated enroute and others are treated at
terminal market. There is concern by the
Florida tomato industry that delayed
ripening initiation may diminish the
quality of the fruit. Preliminary tests
were conducted to determine the effect
of delayed exposure to ethylene on fruit
Packed mature-green tomatoes ex-
posed to ethylene, without delay, ripened
to color 5 (light red) in 16 days while
those fruits that had a 3-day delay before
exposure to ethylene required 24 days to
ripen. Tomatoes that had a 1- and 2-day
delay before ethylene treatment took 20
and 22 days, respectively, to ripen. There
was a linear increase in fruit decay with
time in storage. In previous tests,
ascorbic acid diminishes with increasing
storage time. To optimize tomato quality,
fruit should be exposed to ethylene
without delay. Thus, ripening initiation
should be done in Florida instead of
entransit or at terminal market.
(Gull Vegetarian 89-09)
C. Evaluating Handling/Shipping
Operations for Precooling.
The key to produce quality mainte-
nance is "timeliness"; timely and careful
harvest and transport to the packing-
house, rapid packing and precooling, and
rapid transport to the market or buyer.
Temperature management is essential in
maintaining vegetable quality during
postharvest handling operations, parti-
cularly for Florida shippers selling pro-
duce in distant markets. For many crops,
precooling is the recommended procedure
to extend storage life sufficiently for
shipping and retailing. The purpose of
this article is to review the chief concerns
which must be addressed when evaluating
a particular packinghouse operation for
implementation of precooling.
Temperature Requirements. Precool-
ing is the rapid removal of 7/8 of the
field heat, to temperatures approaching
proper storage temperature and is the
first line of defense in slowing the
biological processes which reduce product
quality. Although many larger packing-
houses incorporate precooling in their
handling operations, smaller packing-
houses often rely on short-term storage in
refrigerated rooms or in some circum-
stances load directly into refrigerated
trailers for shipment.
The storage life or relative perisha-
bility of a crop is reflected in its respir-
ation rate. Once harvested, a vegetable
continues life processes independent of
the plant, and as a result, must utilize its
own reserves. Many crops, such as
greens, celery and lettuce, are cut at
harvest which causes additional stress.
Respiration is the process of life by which
oxygen is combined with stored carbohy-
drates and other components to produce
heat, chemical energy, water, carbon diox-
ide and other products. The respiration
rate varies by commodity; those commodi-
ties with a high respiration rate utilize
the reserves faster and are more perish-
able than those with a lower respiration
rate. Therefore these crops must be
rapidly precooled to slow their metabolism
in order to provide maximum storage life
for shipping and handling operations.
Also, once a product is cooled, the cold
chain must not be broken during
subsequent handling in order to avoid
development of condensation.
Horticultural crops may be grouped
into two general categories based on
sensitivity to storage temperatures.
Those crops which are chilling sensitive
should be held at temperatures generally
above 50 F; the optimal temperature
depends upon the crop. Storage below
this threshold will give rise to chilling
injury. Chilling injury is a physiological
disorder which is characterized by such
symptoms as development of sunken
lesions on the skin, increased suscepti-
bility to decay, increased shrivel, and
incomplete ripening (poor taste, texture,
aroma and color). The degree of chilling
sensitivity, and therefore the lowest safe
storage temperature, is crop dependent.
Those crops not as sensitive to chilling
injury may be stored at lower tempera-
tures to 320. The degree of chilling is
also dependent on the length of exposure
to low temperatures. Short exposure
times will result in less injury than longer
exposure to chilling temperatures.
Storage in a high relative humidity envi-
ronment (above 90%) is normally also
recommended for most fresh crops to
reduce water loss.
Optimal storage recommendations
and precooling methods for individual
vegetable commodities have been compiled
and are available upon request. A method
for determining actual precooling sche-
dules was published previously (Vegetarian
Evaluating Harvest and Handling
Operations. The entire harvest/packing-
house operation must be evaluated, since
the addition of a precooling procedure will
affect all other operations. Field handling
procedures may have to be modified, such
as the adoption of field packing, the use
of harvest aids or harvest into bulk con-
tainers. Produce harvested during early
morning hours will have a lower pulp
temperature than that harvested during
the afternoon, thereby reducing cooling
time and energy costs. Holding time in
the field should be minimized and
containers should be shielded from direct
exposure to the sun. A brief period
under adverse ambient conditions can
rapidly reduce quality and provide false
confidence in assumed storage life of the
product being shipped. Choice of
container style and construction material
may be affected by the precooling method,
such as the ability to withstand prolonged
contact with water or ice, or the necessity
of larger vent openings to permit rapid air
In addition to diligence in proper
temperature management, the use of ap-
propriate handling techniques is essential
in maintaining product quality. Mechani-
cal injury incurred during harvest, pack-
ing and handling operations also reduces
storage life. Cuts, punctures and impact
bruises are caused by excessive impacts
during handling; compression bruises and
abrasions are normally caused during
transport due to inadequate protection by
the shipping container and by overpack-
ing. These injuries reduce quality in
several ways: there are increases in water
loss, respiration rate and susceptibility to
decay, and ripening and senescence are
accelerated due to increased production of
ethylene gas by the injured product.
Palletization should also be evaluated due
to the benefits of reduced mechanical
injury by elimination of handling steps.
Packing line, cold room and loading
dock locations should be in cose proxi-
mity to each other and to the proposed
site of the precooler to minimize handling
and rewarming times. Rewarming will
increase potential for decay because of
condensation which forms on the surface
of the vegetables. These facilities may
require modification to accommodate the
new handling procedure. Additional
utilities must be available, such as water
for hydrocooling, block ice for top icing
and slushing, and increased electrical
supply for larger refrigeration capacity or
ice making equipment. Culls and waste
water must be disposed in a manner
which meets local environmental regula-
Produce which has not been ade-
quately precooled should not be loaded
into refrigerated trailers, since most trail-
ers are designed to only maintain temper-
ature and as such do not have the addi-
tional refrigeration capacity necessary to
remove field heat from an entire load of
produce. Shipping inadequately precooled
loads will result in reduced quality upon
arrival due to elevated rates of respiration
and decay, and increased water loss.
A regular sanitation program is essen-
tial to prevent build-up of pathogenic
populations. Existing field containers and
packing line components (conveyors, brush
rolls, transfer points, etc.) should be
cleaned prior to the start of the packing
season with a disinfecting solution such as
liquid sodium hypochlorite. Periodic
cleaning should be performed during the
packing season as well. Ripening rooms
and cold storage rooms should likewise be
disinfected at the start, during and at the
end of the season.
Precooling should be considered an
integral component of any packing/ship-
ping operation. Application of the above
approach for systematically evaluating
individual farm operations will provide a
basis for understanding current conditions
and the options which are available for
improving efficiency and product quality
to, hopefully, result in higher profits.
(Sargent, Vegetarian 89-09)
III. PESTICIDE UPDATE
A. Mancozeb and Maneb Labels
Have Been Dealt Lethal Blows for
Labels of mancozeb and maneb pro-
ducts (Dithanes, Manzates, Penncozeb,
Manebs, Manex) have been restricted
severely in the past two to three years.
Three weeks ago I presented information
to growers in Palm Beach County that
was based upon the accepted EPA proto-
col for reregistration of the above
products. I indicated to the growers that
the ongoing protocol would allow us the
remaining uses of mancozeb and maneb
products for about 2 years at which time
further label reductions could occur.
Unknown to most of the agricultural
industry, negotiations between manufac-
turers and the EPA have resulted in
severe label reductions for both maneb
and mancozeb effective as soon as new
labels are printed. Again, manufacturers
have been "asked" to play by NEW proto-
cols, "or else." Containers of maneb and
mancozeb that are purchased prior to the
advent of the new labels will be usable as
stated on the old label. New sticker-type
labels will be placed on those containers
that remain for sale by January 1, 1990.
Products shipped from the manufacturers
will have the new labels as soon as they
are printed and no later than January 1,
Specifically, ALL CUCURBITS,
CELERY AND CARROTS will be deleted
from mancozeb labels. BEANS, ALL
CUCURBITS, ALL CRUCIFERS, EGG-
PLANT, LETTUCE, ENDIVE, PEPPERS,
SPINACH, AND TOMATOES will be
deleted from all maneb labels.
The bottom line is that maneb will
be labeled on the following vegetables:
SWEET CORN AND POTATOES, and
mancozeb will be labeled on the following
vegetables: ASPARAGUS, SWEET CORN,
ONIONS, POTATOES, AND TOMATOES.
Also, all seed treatment uses are left in
The value of the vegetable crops in
Florida at the farm level that are im-
pacted upon is in excess of $550,000,000.
In addition, $39,600,000 worth of agro-
nomic crops are also impacted upon.
Tolerances still exist for those crops
* to be deleted from the labels which might
allow us to pursue state or emergency
labels. However, I have been told that
this approach may not be advisable
because such action might blemish the
marketability of Florida-produced vegeta-
bles. The consumer has been told (via
actions or words) by consumer advocates,
the EPA, the NRDC, some Hollywood
types, grocers and produce buyers that
mancozeb and maneb fungicides present
risk to our health. Even some Florida
growers have decided not to use these
products and run the risk of total loss of
their crops, so that they might preserve
the marketability of their crop.
Agriculture is facing serious problems
on many fronts. Growers now have
reduced land (particularly prime agricul-
tural land) on which to farm because of
urban sprawl, suburban sprawl and
government-sponsored land conservation
plans. Our ability to use crop rotation as
a pest control method is in serious
jeopardy. Agricultural chemicals are being
taken away or voluntarily withdrawn in a
wave of hysteria CAUSED BY A RELA-
TIVELY FEW PERSONS AND ORGANI-
ZATIONS. Hype and political action now
determine agricultural production
practices. American growers are being
squeezed on all fronts. The most
effective commodity for balance of trade
for the United States has been quality
agricultural products and this is severely
threatened with recent actions against
agricultural chemicals. Many of us are
concerned with increasing importation of
our food supplies. Other countries
produce food without testing for residue
and quality, so growers there use
unknown quantities of chemicals, some of
which are not available for use in the
United States. Chemicals in other coun-
tries may be applied by hand with no cali-
bration whatsoever. One fruit may have
no residue while another fruit nearby
might contain massive amounts of residue.
In the United States, except for vegetable
gardens, pesticides are usually applied
with equipment that is calibrated to deli-
ver uniform amounts that will not exceed
label restrictions. What are we gaining by
buying a product from another country
that may have excessive chemical resi-
dues, and a product that is in shipment
longer where toxin-producing microbes
have more time to multiply? It makes no
sense to go that route. If the food supply
in the United States has been so danger-
ous, why are humans in the United States
living longer today than in the past?
Three ways exist to get agriculture
out of this dilemma. The first would be
not to grow crops. Some people have
already made this frightful decision. The
second way is to use alternate technology
to control pests. I support this idea, but
what are the alternatives? The third way
is for the majority to counter the
harassing influences of those few who go
to the mass media every time they get a
revelation about how they think we ought
to produce food. It is my understanding
that the American Medical Association has
not condemned maneb or mancozeb. I
have never heard of anyone attaining a
dysfunction directly or indirectly from
these materials in my 27 years of
experience. What is the problem, the
chemical or the those who think there is
(Kucharek, IFAS Plant Pathologist
B. Tomato Transplants Withdrawn
from B-Nine SP Label.
According to Ron Ames, Technical
Manager, Herbicides & Plant Growth
Regulants for Uniroyal Chemical Co.,
tomato has been deleted from the B-Nine
SP (Alar) label as of June 20, 1989. Ames
said the present label simply omits tomato
from the list of crops registered. A
sticker indicating this label deletion will
accompany individual B-Nine SP contain-
ers and packing boxes. This action
represents a voluntary withdrawal of B-
Nine SP by Uniroyal. Growers with B-
Nine SP purchased under the old label
may continue to use it on tomatoes
providing they retain the label and
associated lot number.
A recent article in American
Vegetable Grower (May '89) indicated
paclobutrazol (Bonzai), uniconazol
(Sumagic), propiconizol (Tilt), and
flurprimidol (EL 500) all reduce rank
growth in vegetable transplants in a
manner similar to B-Nine SP. These
plant growth regulators (PGR's) were
discovered in the search for fungicide
chemistry and do have fungicidal activity.
All inhibit the production of gibberellic
acid. A positive side effect of treatment
with these PGR's may be increased field
tolerance to stress (especially temperature
and moisture stress) and air pollution.
It should be remembered however,
that none of these compounds are
registered for use in transplant
production. Valent U.S.A. is considering
registration of uniconazol on vegetable
transplants. Research at the SWFREC
(Immokalee) is presently underway to
characterize the effect of these
compounds on tomato transplants and
subsequent production in Florida.
(Vavrina Vegetarian 89-09)
IV. VEGETABLE GARDENING
1989 Vegetable Gardening
Palm Beach County horticulture
agent Gene Joyner has released the
results of his vegetable gardening survey
conducted in 1989 for the previous
gardening year (1988-1989). While this is
a small survey done in only one county in
South Florida, the results will help those
of us who work in home horticulture to
understand better what our gardening
clientele are doing, -based on their per-
ceptions. Therefore, I am summarizing
the survey results as follows:
Number participating: Male 23, Female
2, Total 46. Urban 33, Rural 13.
Size of garden (Avg): 20' long x 14' wide
(280 sq. ft.).
Soil Amendments Planned: Peat Moss
(16); Animal manure (21); Top soil (20);
Sawdust (2); Compost (5); Grass clippings
Soil fumigation planned: Yes 25; No 8.
Fertilizer planned: Liquid 19; Dry 18.
Favorite vegetables: Tomato, bean, let-
tuce, radish, carrot, pepper, broccoli,
onion, cucumber, eggplant, corn, cauli-
flower, collards, spinach, herbs.
Irrigation planned: Hand 23; Drip 5;
Cost Estimates (per garden)
Weed control $25.00
Was cost justified? Yes 21; No 10.
Preferred pest control: Chemical 15;
Mechanical _6 Combination 23.
Most used insecticides: Malathion 15;
Diazinon 13; Bt 1; Sevin 15; home-made
Preferred Sprays for Disease:
Maneb 1; Dithane 1; Copper
_2 Combination 4.
Most Aggravating Problems:
(2) Diseases; (3) Weeds.
How Vegetables Used: Fresh
1; Frozen 11; Dried 4.
Extension Information Used: Yes 28; No
(Stephens, Vegetarian 89-09)
Prepared by Extension Vegetable Crops Specialists
Dr. D. J. Cantliffe
Dr. G. J. Hochmuth
Dr. S. M. Olson
Dr. W. M. Stall
Dr. C. S. Vavrina
Dr. D. D. Gull
Dr. D. N. Maynard
Dr. S. A. Sargent
Mr. J. M. Stephens ,
Dr. J. M. White