INSTITUTE OF FOOD AND
UNIVERSITY OF FLORIDA
A Vegetable Crops Extension Publication
Vgclt ble Crops Departmentl 1255 ISDD GainesvilIc, n 32611. Telephone 392-2134
August 15, 1988
I. NOTES OF INTEREST
A. Vegetable Crops Calendar.
(;. BB. 1988 Florida Tomato Institute.
II. OCI MERCIAL VEGETABLES
A. Crop Nutrient Requirement Concept.
B. Pumpkin Varieties for Florida.
: / C. Preprint Cartons Image Enhancers.
III. PESTICIDE UPDATE
A. Chlorothalonil Labels on Chinese Broccoli and
i Tight Headed Chinese Cabbage.
IV. VEGETABLE GARDENING
A. Horticulture Events at 1988 State 4-H Club
Note: Anyone is free to use the information in this
I.. 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 product.
The Institute of Food and Agricultural 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.
COOPERATIVF FXTFNSIqN wnRIn I IA A LIOi nil TI e llr unaAi fti CTATr re e r i er. Ir ft itrn-A, &r
I. NUOES OF INTEREST
A. Vegetable Crgcs Calendar.
September 7, 1988. Florida Tomato
Institute, Ritz Carlton Hotel,
Naples. (Contact W. M. Stall).
September 12-15, 1988. State
Extension Conference, Biltmore
September 25-29, 1988. Florida
Fruit and Vegetable 45th Annual
Convention. Ihe Ritz-Carlton Hotel,
September 27, 1988. Soils-Home
Horticulture In-Service Training,
B. 1988 Florida Tomato Institute.
The 1988 Florida Tomato
Institute will be held Wednesday,
September 7, 1988 at the Ritz-
Carlton Hotel, Naples, Florida from
8:30 am to 3:30 pm.
The Tomato Institute, which is
an IFAS sponsored educational
program immediately precedes the
joint Florida Tomato Ccmmittee/
Florida Tomato Exchange Conference
on September 8 and 9.
Hotel reservations may be made
through the Florida Tomato Commit-
tee/Exchange, P. O. Box 140635,
Orlando, Florida 32814-0635.
The program for the Tomato
Institute is as follows:
October 27, 1988. Florida Pepper
Institute: Southwest Florida
Research and Education Center,
(Contact D. N. Maynard).
1988 Florida Tomato Institute
Wednesday, September 7, 1988
W. M. Stall Moderator
8:30 AM -
Registration and Coffee
Welcome D. J. Cantliffe, Chairman, Vegetable Crops Dept.,
Tensiometers as a Management Tool for Micro Irrigated
Tomatoes in South West Florida. G. A. Clark, GCREC,
Evaluating Plant N Status with Plant Sap Quick-Test Kits.
G. J. Hochmuth, Vegetable Crops Dept., Gainesville.
Under-bed Trenching for Mulched Tomatoes on Calcareous
Soils. H. H. Bryan, TREC Homestead.
Size Distribution of Florida Tomatoes:
Report. S. A. Sargent, Vegetable Crops
Problems with Florida Produce at Terminal Markets:
Perceived or Real? P. R. Gilreath, Manatee County
Cooperative Extension Service, Palmetto.
Registration Options for Crop Protection Chemicals.
D. Botts, Florida Fruit and Vegetable Assn., Orlando.
lunch on your own.
S. M. Olson Moderator
Ripening: A New Threat to the Florida Tomato
R. L. Brown, Collier County Cooperative
Update on the Endangered Species Act. O. N. Neisheim,
Pesticide Information Coordinator, Gainesville.
Expression of Bacterial Wilt in Tomato as Influenced by
Cultivar and Lime. S. J. Locascio, Vegetable Crops Dept.,
Dispersal of the Bacterial Spot Pathogen by Hand Operations.
K. Pohronezny, TREC, Homestead.
Nightshade Control in Tomato Row Middles. J. P. Gilreath,
Management of the Sweet Potato Whitefly in the Tomato Crop
of South Florida. D. J. Schuster, GCREC, Bradenton.
II. COMMERCIAL VEGETABLES
Crop Nutrient Reuemnt
Growers spend money on
fertilizers because they have been
shown that these products enhance
crop productivity. Having decided
to fertilize, the critical decision,
then, becomes choices involving how
much of which nutrient to purchase.
A systems approach is the best
approach to solving the above
problem. By understanding the CROP
NUTRIET RETIREMENT concept,
growers will have a workable model
to help with fertilizer-management
Definition. The crop nutrient
requirement (CNR) is defined as the
total amount of a nutrient which is
needed to produce optimum plant
response. Every crop has a CNR for
each nutrient, the so-called 100%
sufficiency level. The key to
understanding the CNR concept is
that the concept considers all
nutritional sources, NOT just that
supplied from fertilizer.
Oh No. An Equation. The
dominant nutritional sources are the
soil and fertilizers. The following
equation illustrates these two
sources of nutrition and their
relationship to the CNR:
CNR = nutrition supplied from the
soil + nutrition from
The Calibrated Soil Test and
CNR. There is no direct method to
determine the amount of a nutrient
supplied from the soil for soil-
immobile nutrients such as P, and to
a lesser extent K and Mg. However,
a predictive, or preplant, soil test
does provide an INDEX of the
nutrition which may be supplied from
the soil. This index from a soil
test is of little value if the index
is not related to positive crop
response. The process of relating
soil-test values, fertilizer
additions, and positive crop
response is called calibration.
This calibration process is time-
consuming; but without calibration,
the soil test can not be interpreted
OR used as a reliable tool for
fertilizer recommendations. In
Florida, the Mehlich I or double
acid extractant is the current
solution used for calibrated soil
testing. Researchers are exploring
other soil extractants and the
Extension Soil Testing laboratory
(ESTL) will continue to use the
current extractant until a superior
extractant is found. Other
extractants, such as Bray P1 and P2,
have not been calibrated for Florida
soil conditions. Recommendations
based upon uncalibrated soil testing
must be considered to be question-
It is important to understand
that a predictive soil test can be
used to estimate the nutrition
supplied from the soil. Then the
amount of fertilizer can be adjusted
to insure that the CNR is satisfied.
If a predictive soil test is
interpreted as "VERY IW", then the
CNR must be supplied mostly from
fertilizer addition. In terms of
probability, a soil testing in the
very low range will produce less
than 50% of the crop yield
potential if no fertilizer is added.
For most crop production, less than
50% of the crop potential is
tantamount to crop failure, due to
the simultaneous loss of quality and
quantity. Conversely, if the soil
test indicates a "HIGH" soil-
nutrient" condition, the soil can
supply 100% of the CNR and
fertilizer need not be added. The
CNR will be satisfied from nutrition
already within the soil and response
to added fertilizer is not expected.
Attainable Yields MY). NOT
Maximum Yield. The Crop Nutrient
Requirement concept works. Table 1
has been prepared to show that top
yields are possible. Yields from
fertilizer research and grower
demonstrations have shown that IFAS
recommendations, based upon soil
testing, can produce competitive
results. In terms of grower
management, yields are near the
upper range using the maximum
economic yield approach to total
Table 1. Representative yields from IFAS fertilizer experiments compared to
state averages by commodity for 1986.
Coamodity State average IFAS yields Unit
Tomato 1,240 2,750 25-lb.ctn./acre
Pepper 585 1,540 25-lb.ctn./acre
Sweet corn 220 320 crates/acre
Watermelon 157 365 crates/acre
1. Vegetable Summary 1986=1987. Florida Agricultural Statistics
Service, 1222 Woodward St., Orlando, Florida.
2. Maynard, D. N. 1987. Vegetable Variety Trial Results in Florida
for 1986. University of Florida Extension Circular S-341.
(Hanlon, Hochmuth, Veg. 88-08)
Pumpkin Varieties for
Pumpkins are in great demand,
mostly for decorative purposes, from
mid-October until late November for
the Halloween and Thanksgiving
holidays. Only a few hundred acres
of pumpkins are grown in Florida so
that production is not nearly enough
to meet demand. Accordingly, most
of the pumpkins used in the state
are shipped in, primarily from the
midwest. There is opportunity,
therefore, for increased pumpkin
production in Florida.
Variety evaluations were
conducted on a commercial farm in
Manatee County and at the Central
Florida Research and Education
Center Leesburg in the 1987 season
to identify varieties suitable for
production in Florida. These are
listed under size designations so
growers can select varieties to meet
Giant 25 to 80 lbs.
Big Max open pollinated
Big Moon open pollinated (PVP)
Large 10 to 30 lbs.
Connecticut Field open
Howden open pollinated (PVP)
Medium 5 to 10 lbs
Autumn Gold hybrid
Young's Beauty open
Small 1 to 5 lbs.
Baby Pam open pollinated
Little Lantern open
Miniature < 1 lb.
Munchkin open pollinated
Sweetie Pie open pollinated
Growers are advised that
production of pumpkins in the
summer and early fall requires
stringent pest management
practices, especially for foliar
diseases. As with other vegetable
crops, a market should be
established before planting.
(Maynard, Veg. 88-08)
C. PREeRIT C T Imae
"They're bold, striking, vivid,
sophisticated, and maybe even
shocking. Despite being just
cartons, they've became a strategic
part of shippers' marketing
efforts". looking for ways to
attract attention, retailers and
wholesalers are enthusiastic about
the vivid preprinted cartons gaining
shippers' favor. They believe
bright and varied colors make more
people look at product in the
carton. Grower/shippers are vying
for enhancement of their product
with buyers but first, "you have to
get their attention"; PREPRINTS
are very effective attention
getters. Compared to direct-printed
cartons, preprinted cartons vividly
accommodate complicated graphics and
a larger number of colors,
admittedly at more expensive costs.
On a recent trip to the New
York/New Jersey receiving markets
for Florida vegetables, a number of
county extension faculty viewed
arrival condition of our products in
comparison with those produced at
other locations. Although consensus
was that Florida was competitive, it
was readily recognized that there is
substantial need for improvement of
Florida vegetables. Can we afford a
"classy carton" filled with "first
rate" produce? Or, can we afford
Preprinted cartons were
originally aimed at retailers who
liked the fancy boxes for store
display. Now, wholesalers find
preprinted cartons add class to
terminal displays. However, the
real attraction of preprints to the
shipper is a means to differentiate
their product, a way to stimulate
buyer interest, not just an "eye
Although Western and Florida
citrus industries were among the
first to utilize preprinted cartons,
during the last three years more
than 20 shippers of products such as
strawberries, apples, onions, and
yams (sweet potato) have started
using these colorful cartons.
According to Cheryl Benson, a sweet
potato grower in Benson, NC, what
they wanted to get across was "Con-
sumer, look at me. I'm just not an
ugly old potato. I'm really
something that's good for you". The
preprinted carton paid off
tremendously. It gave the sweet
potato publicity on its nutrition
and it gave the company a
substantial increase in business.
Vidalia sweet onions are a
specialty crop and some growers are
merchandising them in preprinted
cartons. Growers feel they have a
quality product and they want to
project this image to the people by
shipping in a special package.
Appearance is not the only
advantage preprint cartons have.
Because of construction differences,
these cartons are also stronger then
direct-print cartons. However, cost
is still the big differential.
Another innovative carton soon
to make its debut is the eight-sided
box designed for cabbage. Packaging
Corp. of America has just completed
testing this new carton. Claimed
advantages of this eight-sided box
are that shape is more compatible
with the shape of cabbages, it is
stronger than conventional
corrugated boxes, offers more
protection to the product, stacks
more efficiently in trucks and
coolers, allows more ventilation
holes so cooling takes half the time
of wooden crates, and boxes are
self-locking on both top and bottom
and can be packed in either field or
(Gull, Veg. 88-08)
A. Chlorothalonil labels on
Chinese Broccoli and Tight Headed
Chlorothalonil products (Bravo
500, 720, 90G) have obtained
supplemental labels for the control
of alternaria leaf spot and downy
mildew on Chinese broccoli and tight
headed Chinese cabbage. These
labels were developed in response to
IR-4 work obtained crop group
tolerances and performance data
generation by Ken Shuler.
Supplemental labels must be in
possession of the user at the time
(Stall, Veg. 88-08)
IV. VEGETABLE GARDENING
A. Horticulture Events at
1988 State 4-H Club Congress.
State 4-H Congress was held on
the UF campus July 25-28, 1988. Two
major horticulture competitive
events were part of the week's acti-
vities. These were the Plant
Science Demonstrations and the Hort-
iculture Judging and Identification
Winners of these two events,
along with the state garden record
winner, were recognized at the
awards banquet on the last night of
Here are the winners in the
various horticulture events for
Gardening Record: Joe Judge, Leon
County, wins trip to National 4-H
Congress, Chicago, Dec. 2-9, 1988.
Sponsored by: Chevron Chemical Co.,
Plant Science Demonstrations: Tycee
Betts, Manatee County, wins trip to
NJHA Convention, Chicago, Hyatt
Regency Oak Brook, Oct. 28-31, 1988.
Sponsored by Florida Fruit and
Horticultural Identification and
Judging. Marion County, members
Claudia Craven, Danny lane, Kim
Charles, and Yogi Williams. High
individual award: Kim Charles,
Marion County. Coach was Bob
Renner, Marion County 4-H Agent.
Team wins trip to compete against
other top state teams at National
Junior Horticultural Association
Convention, Chicago Hyatt Regency
(Oak Brook) Oct. 28-31, 1988.
Sponsored by Florida Fruit and
Vegetable Association, Orlando.
The following are results of the two
major competitive events in the
Plant Science Demonstrations
1 Tycee Betts
2 Leanne Barco and Edwin Rooks
3 Francine Huggins
4 Lin Sperlanes/Jenni Stephens
5 Danette Kosola
6 Amy Theus and Leslie Theus
7 Dwayne and Belinda McQuillan
8 Kevin Crowell
9 Jonathan Hill
10-T Charlotte Riley
10-T Dawn March
12 Steve Forehand
13 Michael Lucas and Susan Lucas
14 Heather Anderson
15 James Watkins
16 Dan Thomas
17 Amy Thompson
18 Mark Fooshee
Judges: Susan Carr (VC); Leah Willis
92.3 Cold Protection/Citrus
90.6 Grafting the Rose
90.3 Natural Attractions
88.6 Tissue Culture
88.0 Thorobred Trees
85.0 Hybridizing Plants
82.3 Watermelon Production
82.3 Tropical Trees Around World
81.6 Propagation of Fruit Trees
77.3 Aquatic Gardening
76.0 Summer Color for the Patio
74.3 Air Layering
73.3 Care of Our Soils
70.6 Mounding Tomatoes
(FC); Chrisi Murphy (OH)
4-H Horticulture Identification and Judging-1988
Rank County Score
1 Marion 2,561.00
2 Clay 1,990.50
3 Sarasota 1,748.75
4 Martin 1,477.75
Congratulations to all these participants and winners for a job well done.
(Stephens, Veg. 88-08)
Prepared by Extension Vegetable
Dr. D. J.
Dr. S. M. Olson
Dr. D. N. Maynard
Mr. J. M. Stephens
Dr. G. J. Hochmuth ;(
Assistant Profess '
Dr. D. D. Gull
Dr. W. M. Stall