UNIVERSITY OF Cooperative Extension Service
FLORIDA Institute of Food and Agricultural Sciences
A Vegetable Crops Extension Publication
viJ a Horticultural ciWncc Department P.O. 110690 Gainesville, FL 52611 Telephone 904/392-2134
January 17, 1995
I. NOTES OF INTEREST
A. Vegetable Crops Calendar.
II. COMMERCIAL VEGETABLES
A. Calibrated Soil Testing.
B. Seedless Watermelon Cultigen Evaluation Spring 1994.
III. VEGETABLE GARDENING
A. FL27 State Major Program for Homeowner Fruits and
IV. UPCOMING EVENTS
A. 1995 Seedsman Seminar.
B. 1995 Florida Postharvest Horticulture Institute &
Note: Anyone is free to use the information in this newsletter.
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Information and does not necessarily constitute a recommendation of
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information and other services only to individuals and institutions that function without regard to race, color, sex, age, handicap or national origin.
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I. NOTES OF INTEREST
A. Vegetable Crops Calendar.
February 2, 1995. Strawberry Field
Day at the Dover Center. (Contact Will E.
March 2, 3, 1995. 1995 Florida
Postharvest Horticulture Institute. Holiday
Inn West, Gainesville. (Contact S.A. Sargent,
904-392-2134 ext. 215).
March 6-9, 1995. Harvest and
Postharvest Handling of Horticultural Crops.
Industry Tour. (contact S.A. Sargent, 904-
392-2134 ext. 215).
March 9, 10, 1995 Florida
Science Society Annual Meeting.
Augustine. (Contact W. M. Stall)
II. COMMERCIAL VEGETABLES
A. Calibrated Soil Testing.
Calibration. Soil tests are calibrated if
they can accurately predict crop response to
fertilization based on the concentration of a
nutrient found in the unfertilized soil. Some
extractants are insensitive to the concentration
of an element in a soil and therefore can not be
calibrated for those growing areas. You want
to select labs that employ extractants that have
been calibrated for your growing area. During
the calibration research phase, certain soil
nutrient concentrations (let's use potassium as
an example) might be determined to be "low"
and other concentrations determined to be
"high". Crop growth on "low" soils is poor
and growth on "high" soils is usually normal
with maximum yields. Using the "low",
"medium", and "high" testing soils,
fertilization research is conducted to determine
the amount of fertilizer (KO2) needed to
supplement the native soil K and achieve
maximum yield and quality.
Soil test reports. Growers are often
perplexed by various soil test report formats
and conventions. Extractable nutrients are
often reported in parts per million (ppm) or
pounds per acre (lb/A). It is important for the
report user to realize that the ppm value was
the number determined in the lab from the soil
sample while lb/A was calculated by
multiplying ppm by 2. This math is based on
the idea that there are 2 million lbs of soil in an
acre furrow slice which is, in itself, a gross
estimation. Therefore the math is not strictly
accurate for all soils tested by a lab.
Furthermore, the "lb/A" designation leads to
confusion because soil test users assume that
"lb/A" means "available lb/A". The
uninformed user might subtract the Ib/A on the
soil report from a crop nutrient requirement
from a book and derive a fertilizer
recommendation. For example, a sweet corn
K requirement might be 150 lb K per acre and
the soil test report said 70 lb/A of K in this
soil. It would not be proper to subtract 70
from 150 and recommend that 80 lb of K be
applied. The value "70 lb/A" might have been
correctly interpreted as "high", meaning no
fertilizer was required. Remember that the soil
test numbers on the report are extracted
nutrients and are called soil test index values.
They are an index to the soil fertility and need
to be interpreted as "low", "medium", "high",
etc. to be of use in determining a fertilizer
(Hochmuth, Vegetarian 95-01)
B. Seedless Watermelon Cultigen
Evaluation Spring 1994.
The concept of seedless watermelons
was described first in the U.S. literature by
Kihara based on experimentation that began in
Japan in 1939. Seed for planting seedless
watermelons results from a cross between a
selected tetraploid female parent, developed by
treating diploid lines with colchicine, and a
selected diploid (normal) male parent. The
resulting triploid is sterile and does not
produce viable seed. However, small, white
rudimentary seeds develop which are eaten
along with the flesh just as immature seeds are
eaten in cucumber.
Fruit enlargement in normal fruit,
including watermelon, is enhanced by growth-
promoting hormones produced by the
developing seed. Growth hormones are
lacking in seedless watermelons so those
agents must be provided by pollen. Since
flowers on triploid plants lack sufficient viable
pollen to induce normal fruit set, normal
watermelons are interplanted with triploids to
serve as pollenizers. An adequate bee
population is necessary to insure that sufficient
transfer of pollen occurs. Seedless fruit (from
triploid plants) tend to be triangular shaped
without sufficient pollination.
Although the procedure for production
of seedless watermelons has been known for
almost 50 years and commercial varieties have
been available for nearly 20 years, the interest
in and acreage of seedless watermelons has
remained small. Erratic performance, poor
seed germination, high seed costs, and
inadequate varieties resulted in the lack of
interest in seedless watermelon production.
Specialty vegetables are in high
demand and seedless watermelons offer an
attractive alternative for discriminating
consumers and the food service industry.
Seedless watermelons are being actively
promoted by marketing organizations and
seed companies to stimulate demand. At the
same time, new varieties are being developed
that are superior to those previously available.
The objective of this trial was to
evaluate the performance of seedless
watermelon cultigens under west-central
Seeds of 25 seedless watermelon
varieties or experimental lines for replicated
trials and 25 entries for observational trials
were planted in a peat-lite growing mix in No.
150 Todd planter flats on 28 January. The
watermelon transplants were grown by a
commercial plant grower.
The EauGallie fine sand was prepared
in early February by incorporation of 0-1.2-0
lb. N-P205-K20 per 100 linear bed feet (lbf).
Beds were formed and fumigated with
methylbromide:chloropicrin, 67:33 at 2.3
lb/100 lbf. Banded fertilizer was applied in
shallow grooves on the bed shoulders at 2.7-0-
3.8 lb. N-P20s-K,0/100 lbf after the beds were
pressed and before the black polyethylene
mulch was applied. The total fertilizer applied
was equivalent to 130-60-182 lb N-P20,-
K20/A. The final beds were 32 in. wide and 8
in. high, and were spaced on 9 ft centers with
four beds between seepage irrigation/ drainage
ditches which were on 41 ft centers.
Standard watermelons that were being
evaluated were direct seeded in beds on each
side of two seedless watermelon beds on 15
February to serve as diploid pollenizers. Weed
control in row middles was by cultivation and
applications of paraquat. Pesticides were
applied as needed for control of silverleaf
whitefly endosulfann and esfenvalerate), aphids
endosulfann), and gummy stem blight
(chlorothalonil and metalaxyl-chlorothalonil).
Watermelons were harvested on 25
May, 2 June, and 9 June. Marketable (U.S.
No. 1 or better) according to U.S. Standards
for Grades were separated from culls and
counted and weighed individually.
Early yields, represented by the first of
three harvests, ranged from 42 cwt/acre for
'Sunrise' to 290 cwt/acre for 'Genesis'. Early
yields of 18 other entries were statistically
similar to those of'Sunrise' whereas 20 other
entries had yields similar to those of'Genesis'.
Average fruit weight ranged from 6.4 lb for
'Sunrise' to 16.7 lb for RXW 701. Average
weight of fruit at first harvest of 22 other
entries was similar to that of'Sunrise', whereas
23 other entries had average fruit weight
similar to that of RXW 701. Soluble solids of
fruit from the first harvest varied from 11.9%
for 'Ssupersweet 4073' to 13.6% for 'Tiffany'.
There were few differences in yield, average
fruit weight, or soluble solids at the first
Total yields ranged from 461 cwt/acre
for 'Flordalee In' to 842 cwt/acre for 'Crimson
Trio', but were statistically similar. Average
fruit weight for the entire season varied from
8.3 lb for 'Chiffon' to 16.9 lb for 'Millionaire'.
Total yields far exceeded the state average
yield of about 198 cwt/acre for the 1988-89 to
1992-93 seasons. Soluble solids over the
entire season ranged from 11.5% for
'Ssupersweet 4073' to 12.9% for W0010, but
these differences were not significant.
Accordingly, soluble solids in all entries far
exceeded the 10% specified for optional use in
the U.S. watermelon grade standards for very
good internal quality.
Seedless watermelon variety trials have
been conducted at this location each spring
season since 1988. The highest yields have
ranged from 546 cwt/acre in 1991 to 1161
cwt/acre in 1993. In spring 1994, the highest
yield in the replicated trial was 842 cwt/acre
which was somewhat more than the 795
cwt/acre average yield of the previous six
years. 'Millionaire' was included in five of the
six replicated trials (observational trial in 1993
because of the 'Storm of the Century') and
was the highest yielding variety in three of the
trials and in the statistically highest yielding
group in two other trials.
Based on results of this and previous
trials, varieties, in alphabetical order, that
appear to have considerable potential for
commercial production in Florida include
'Crimson Trio', 'King of Hearts', 'Millionaire',
'Ssupersweet 2532', 'Ssupersweet 5032',
'Ssupersweet 5244', 'Tiffany', and 'Tri-X-313'.
'Merrilee In' should be considered for trial
(Maynard, Vegetarian 95-01)
III. VEGETABLE GARDENING
A. FL27 State Major Program
for Homeowner Fruits and Vegetables.
The purpose of this program is to
promote the growing of fresh vegetables and
fruits for home consumption and to improve
the skills and knowledge necessary for
successful gardening endeavors in all 67
Florida Counties, including the federally
targeted city of Jacksonville.
This is to remind county agents who
are working with home fruit and vegetable
gardeners (10 days or more within the fiscal
year), that work should be planned and
reported under State Major Program FL27. It
seems to me that a lot more work is going on
in this program than is being reported by
There is still some confusion about
where to report Master Gardener program
work. Keep in mind that projects, activities
and educational outreach performed by Master
Gardeners should be reported (in most
instances) under one or two SMPS: a) FL14,
Environmental Landscape Management in
Florida, if work is on lawns, ornamentals,
landscape trees and shrubs, and b) FL27,
Florida Urban Gardening Program, if work is
on home fruits and vegetables.
Programs designed for Master
Gardeners, such as recruiting, organizing,
training, and deploying, should be reported
Accomplishments/Impacts In 1994,
nine counties reported under FL27 Baker,
Duval, Jefferson, Lafayette, Liberty, Manatee,
Orange, Polk, and Washington (total clientele
of 17,000). The following are some of the
UF (Gainesville As a result of
demonstrations held at the Organic Gardening
Research and Education Park, gardeners can
help prevent organic waste from entering
landfills, while reducing water and chemical
fertilizer needs in their gardens. A slide video
tape and accompanying fact sheet were
prepared on the benefits of using various soil
organic amendments. These may be obtained
by contacting the IFAS film library and asking
for V.T. 1107, Producing Garden Vegetables
with Organic Soil Amendments, and IFAS
Center for Biomass Programs to get the fact
sheet EES-327 (same title).
Duval The Jacksonville Urban
Gardening staff was greatly reduced due to
budget cuts in 1994. However, with the help
of Duval Master Gardeners, extension worked
with 20 community gardens (containing 123
plots), and 263 home gardens, for a total of
1524 adult gardeners. The total value of all
gardens in the Urban Gardening project was
One of the more successful
Jacksonville UG community gardens continues
at the Fort Caroline site. Started 10 years ago
by the "Gardening Lots" staff, this one-acre
site on church property contains 18 garden
plots and 20 gardeners. What makes this
particular garden unique is the degree to which
the gardening participants have organized
themselves. There is a president who oversees
rules and regulations and major aspects of the
garden project. The secretary edits and mails
to all participants a monthly newsletter. The
treasurer collects a $2.00 weekly fee per
garden plot, and makes disbursements to pay
The group has developed an irrigation
control system for solving one of the most
severe problems: how to water plants in a
state with government imposed water
restrictions. Each garden plot has drip lines
connected to an individual water-metering
device. Thus gardeners are charged only for
the amount of the water used on their plot.
Watering schedule (strictly followed), allows
everyone to get water and prevents over
loading the system during any one hour. Rules
prohibit watering outside the allotted times,
except by hand held hoses. Equipment has
been purchased to help till all plots, with labor
provided by volunteers. This garden at Fort
Caroline (Jacksonville) expresses a degree of
togetherness and community pride that all
other community gardens might be wise to
Orange a survey showed 54% of
respondents said their garden was more
successful due to Extension help; 28%
switched to safer pesticides; 21% were now
conserving water; and 35% were now using
more efficient ways to fertilize and 100% of
those surveyed had a better understanding of
biological pest controls as a result of Orange
Co. Extension efforts.
Manatee about 55 gardeners learned
how to solarize gardens for soil pest control.
They also learned how to "scout" more
diligently to reduce chemical treatments.
Liberty and St. Johns a county wide
vegetable gardening contest was held by
extension in each county. In these contests,
participating gardens (30 in St. Johns, and 12
in Liberty) were visited by extension workers,
providing an opportunity to educate gardeners
of better ways of growing vegetables.
Elsewhere from a statewide
perspective, the Florida Master Gardener
program, with all of its projects and activities,
continues to be of paramount importance to
this FL27 state major program called Urban
Gardening. Within this program, such re-
active efforts as telephone contacts, office
visits and clinic consultations remain foremost
among several methods of reaching home fruit
and vegetable gardeners. Gardening meetings
of all types are conducted regularly by county
extension staffs statewide.
Several counties utilized mass media
approaches to reaching urban gardeners.
Orange County is a good example, where
outstanding work is conducted with radio,
television, and the newspaper.
Demonstration gardens were also of
key educational importance in other counties,
some of which were Baker (30X30 foot
garden behind the extension office); St. Lucie
(similar); Putnam (similar); Osceola (similar);
Manatee (2 gardens); Nassau (included a grant
study); and Orange County (a water-wise
garden). Master Gardeners were usually
actively involved with these demonstration
Finally, annual fairs and exhibition
events held around the state provided ample
opportunity for extension workers to reach
gardeners, gardening related enterprises, the
general public, and public officials.
(Stephens, Vegetarian 95-01)
IV. UPCOMING EVENTS
A. 1995 Seedsman Seminar.
1995 Seedsman Seminar
Holiday Inn West, Gainesville
Wednesday, February 8, 1995
Moderator Richard Wojciak (Sunseeds)
1:00 Presidents Address Allen Stevens (Florida Seed Co.)
1:15 John Cross (Seed Specialists, Inc.) Seed health
Watermelon Fruit Blotch
1:45 Tom Kucharek (UF) Growers perspective
2:05 Dick Barrett (Plants of Ruskin) Transplant producers perspective
2:25 Wayne Weibe (Peto) Seed industry perspective
2:45 Don Hopkins (UF) Public research perspective
3:05 Darrell Maddox (STA Labs) ASTA position on watermelon fruit blotch & techniques
for WFB identification
Revamping the FL Seed Laws
3:45 Don Maynard (UF) Arbitration past history, recent cases
4:05 Rick Anderson (Peto) Problems with the existing seed law
4:25 Dale Dubberly (FDACS) FL seed law
4:45 Discussion & Adjournment
6:00 FSGS Social Hour & Banguet
Thursday, February 9 1995
Moderator Paul Sawyer (Abbott & Cobb)
08:30 Paul Kummiskey (Earl J. Smalls Growers) Experiences with seed quality as a producer/user
08:50 Roger Styer (Pan American) Matching seed quality to plug producers needs
09:10 Bob Croft (Sakata Seed) Flower seed quality: Exploiting the potential
09:30 Bruce Christensen (Pan American) Troubleshooting in the flower seed industry
10:10 Brett Callaway (Pioneer Seed) Corn germplasm preservation
10:30 Ken Owens (Peto) Hot peppers
10:50 John Reynolds (Asgrow) Virus resistance in cucubits by virus coat proteins mediated
11:10 Rob Ferl (UF) Lettuce engineered for Glyphosate tolerance
11:30 Harry Klee (UF) Engineering tomatoes & strawberries for better quality
(Vavrina, Vegetarian 95-01)
B. 1995 Florida Postharvest Horticulture Institute & Industry Tour.
1995 FLORIDA POSTHARVEST HORTICULTURE INSTITUTE & INDUSTRY TOUR
Holiday Inn West, Gainesville
Seminar: March 2,3; Industry Tour: March 6-9
At the Postharvest Insititute the latest practical information is presented by University of Florida faculty and other experts
for maintaining postharvest quality of fruit (tropical and sub-tropical), vegetables and ornamental crops for domestic and
export markets. The Institute is designed for industry professionals involved in postharvest handling of horticultural crops
in such diverse areas as field and packinghouse management, sales, import/export, wholesaling, retailing, extension
education and students.
The Friday afternoon session will include hands-on demonstrations on temperature and relative humidity measurement and
cooling principles and methods. A display area will be available for industry exhibits on both days.
The Postharvest Industry Tour will provide an opportunity to experience first hand the latest technologies for
handling and shipping a variety of horticultural crops. Participants will visit harvest, packing and shipping operations
throughout Florida, as well as a port facility and warehouse operations. The tour will depart from Gainesville on Monday
moving, March 6, and return to Gainesville on Thursday evening, March 9. Tour enrollment will be limited to 35 persons.
THE DEADLINE FOR EARLY REGISTRATION IS FEBRUARY 10, 1995.
Institute:575.00 by Feb. 10; $95.00 after. Fee includes the reference notebook, luncheons on both days and
the evening banquet on Thursday.
Tour: $150.00 by Feb. 10; $170.00 after. Includes transportation only; meals and motel are extra (4 days/3
Optional reference material: $10.00 (USDA Handbook 66. "The Commercial Storage of Fruits,
Vegetables, and Florist and Nursery Stocks" (130 pages).
Hotel reservations in Gainesville may be made by calling the Holiday Inn West. Request group rates for the Postharvest
Horticulture Institute ($49.00 per night, single, or $59.00, double). Make reservations at 800-551-8206 or 904-332-7500.
The special rate includes a coupon to purchase the hot breakfast buffet for $2.99.
REGISTRATION FORM RETURN BY FEBRUARY 10, 1994
Day Phone: FAX:
Before Feb. 10 After Feb. 10 Amount
Institute $75 $95
Tour $150 $170
USDA Handbook 66 ($10)
I am also interested in: Registering for one graduate credit Exhibit space for my company
MAKE CHECKS PAYABLE TO: Florida Fruit and Vegetable Association Research Foundation.
MAIL REGISTRATION FORM AND PAYMENT TO:
Holiday Inn West, c/o Ann Fowler, Catering. 7417 NW 8th Ave., Gainesville FL 32605
(Tel. 904-332-7500; Fax: 904-332-0487)
Institute Coordinator: Dr. Steven A. Sargent. (Tel. 904-392-1928, ext. 215; Fax: 904-392-5653).
Prepared by Extension Vegetable Crops Specialists
Dr. D. J. Cantliffe
Dr. S. M. Olson
Mr. J. M. Stephens
Dr. G. J. Hochmuth
Dr. S. A. Sargent
Dr. C. S. Vavrina
S i/ Dr. D. N. Maynard
L r Vr-- Professor
Dr. W. M. Stall
Dr. J. M. White