A Vegetable Crops Extension Publication
University of Florida
Institute of Food and Agricultural Sciences
Cooperative Extension Service
(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 product.)
* On-Farm Demonstration of a Controlled Release Fertilizer Program for Potato Production
* GCREC Winter 2001-2002 Cabbage Variety Evaluation
* GCREC Fall 2001 Tomato Variety Evaluation
* Sweet Onion Variety Trial, Spring 2002
* Section 18 for AIM for Tomato, Pepper and Eggplant Row Middles
* Section 18 for Sandea on Tomatoes
(no article this month)
List of Extension Veaetable Crops Specialists
American Society for Horticultural Sciences (in conjunction with XXVI International Horticultural Congress). Toronto, Ont.,
Canada. August 11-17, 2002.
Florida Tomato Institute. Ritz Carlton Hotel, Naples, Fla. Begins September 4, 2002. Contact Charles Vavrina for information.
I C V geb Pr u ction
On-Farm Demonstration of a Controlled Release
Fertilizer Program for Potato Production
A Cost Share Program to encourage Best Management Practices (BMP) has been implemented for growers in the Tri-County
Agricultural Area (TCAA, St. Johns, Putnam, and Flagler counties) in Northeast Florida. The program is managed by the St. Johns
River Water Management District (SJRWMD). The goal of the BMP program is to reduce non-point source nitrate pollution from the
38,000 acres in agricultural production in the lower St. Johns River watershed.
The BMP nitrogen rate for potato production in the TCAA is 200 Ib N/acre. Growers are concerned, however, that this nitrogen rate
may not be sufficient to produce historical yields in all years. In years with heavy rainfall, nitrogen can be leached from the beds making
it both unavailable to the potato plant and a potential pollutant. Provisions to allow growers to apply more nitrogen have been made in
the BMP program for such occurrences. However, depending on when rainfall events occur, growers may not be able to side-dress the
crop before the critical tuber bulking stage.
Controlled release fertilizers (CRF) could overcome the concerns of growers and regulatory agency personnel by supplying nutrients to
the crop over the entire season while reducing the chance of off-site movement of nitrogen. This is possible because CRFs meter out
nitrogen to the plant gradually. The timing of nutrient release from the CRF prill is dependent on soil temperature and polymer coating
thickness on the prill and not soil moisture. CRFs blends can be developed that release nutrients based on the timing of crop demand.
Therefore, CRFs can be a more efficient method of fertilizing a crop i.e. more fertilizer ends up in the crop and less is available to move
A CRF program was developed for an on-farm trial in spring 2002 based on two years of results from small plot trials at the University of
Florida's Yelvington Farm. The goal of the demonstration was to compare potato production after application of a grower applied BMP
fertilizer program (200 Ib N/acre) to a CRF program (150 Ib N/acre).
The experiment was conducted on a 235 acre chip potato farm in the Hastings area. The soil type was Ellzey fine sand and the crop was
irrigated with sub-surface (seepage) irrigation. The experiment was arranged in a randomized complete block design with three blocks.
Blocks were spaced at three varied locations on the farm. The two treatments were CRF and grower applied BMP fertilizer program.
CRF plot sizes in each block were 0.87, 0.70, and 0.97 acres. Grower plots were adjacent to each CRF plot and were of similar size.
Potatoes (var. 'Atlantic') were planted on February 6 and 11, 2002. All production practices in both plots were the grower standard
practices except for the application of CRF.
The grower applied 225 Ib P/A and 330 Ib K/A in both the CRF and grower BMP beds prior to planting. The nitrogen program for the
grower BMP beds was 124 and 81 Ib N/acre applied on February 26, 2002 and March 22, 2002, respectively. The nitrogen source was
The CRF nitrogen program was a 50:50 (N rate) mix of 37-0-0 and 43-0-0 products (The Scotts Company, Marysville, OH) broadcasted
and incorporated at layby, 21 days after planting. A total of 150 Ib N/acre was applied.
Eight sub-plots, each 20 feet long, were harvested from each plot on May 22, 2002. Potatoes were transported to the University of
Florida's Yelvington Farm where they were washed and graded with commercial equipment into five standard size classes. Specific
gravity was measured by the weight-in-air/weight-in-water method.
This on-farm trial demonstrated the potential of a CRF program in potato production in the TCAA. Potato plants fertilized with the CRF
program (150 Ib N/acre) produced 21 cwt/acre more tubers in total yield than plants fertilized with the grower BMP nitrogen program
(200 Ib N/acre) without negatively impacting quality or grade Table 1).
Additional trials are planned for next season with "second-generation" CRFs. These materials will be blended to more closely match the
uptake requirement of the potato plant. If production results remain constant after future testing, a savings of 50 Ib N/acre without a
yield loss would be a positive step forward for growers and regulating agencies in the TCAA. This would result in one million pounds
less nitrogen applied in the lower St. Johns River basin annually.
Material cost is the last challenge to be overcome before wide-scale CRF use becomes a reality in row crop production. Cost of CRFs to
the growers in the TCAA will ultimately be determined by the rate of material used, pricing by the manufacturer based on large scale
production (economies of scale), and whether CRFs are adopted as a reimbursable BMP in the SJRVMD Cost Share Program.
Table 1. Yield of 'Atlantic' potatoes grown with a controlled release fertilizer program (150 Ib N/A) and a grower applied BMP
fertilizer program (200 Ib N/A) on a commercial farm in Hastings, FL..
Fertilizer Program (cwt/A)
Grower Practice 343
200 Ib N/acre
150 Ib N/acre
Marketable Yield '
Distribution by Class (':.:.) -
(':' .:. )
1 2 3 4 5 2 to 4 3 to 4
4 47 45 4
108 3 42 50 5
.: Speci ic
0 96 49 1 1.080
0 97 55 1 1.078
0.8 ns 4.5 ns
0.04 0.09 0.04 0.63
0.9 5.3 ns ns
1Marketable Yield: size classes 2 to 4.
2Size classes: 1 = <1 7/8", 2 = 1 7/8 to 2.5", 3 = 2.5 to 3.25", 4 = 3.25 to 4", 5 = >4"; Size Distribution by Class was
calculated with the following formula: Class (wt)/Total Yield (wt) culls (wt).
3Culls: growth cracks, sun-burn, miss-shapes, and/or rots.
4Means separated within columns with LSD mean separation test.
(Hutchinson, Austin Tilton, extension agent, Putnam County, and Simonne, Vegetarian 02-06)
GCREC Winter 2001-2002 Cabbage Variety Evaluation
Cabbage was harvested from 7900 acres in Florida in the 1999-2000 season. The average yield was 507 50-lb crates per acre and the
total production was over 4 million crates. With an average price/crate of $5.04 the crop was worth over 20 million dollars. Florida
ranked fourth among the states in value of fresh market cabbage, exceeded only by California, New York, and Texas.
The EauGallie fine sand soil was prepared in mid-November 2001. Beds were formed and fumigated with methyl bromide:chloropicrin,
67:33 at 350 Ib/treated acre. Banded fertilizer was applied in shallow grooves on the bed center after the beds were pressed and before
the black polyethylene mulch was applied. The total fertilizer applied was equivalent to 220-0-304 Ib N-P205-K20/acre. The final beds
were 32-in. wide and 8-in. high, and were spaced on 5-ft centers with six beds between seepage irrigation/drainage ditches which were
on 41-ft centers.
Seeds were sown on 17 October into 1.5 x 1.5 x 2.5 inch containerized cells of Styrofoam transplant flats filled with a commercial mix.
Supplemental nutrients were supplied periodically as liquid 20-20-20 (N-P205-K20). The seedlings were hardened by withholding water
and nutrients during the final phase of production.
Transplants were set in the field on 27 November in two rows per bed with plants spaced 12 inches within rows and each row was 8
inches to each side of the bed center. Twenty-four plant plots per entry were arranged in a randomized complete block design with four
replications. Data was collected from the center 20 plants in each plot.
Cabbage was harvested with three to four wrapper leaves, graded for marketability, measured and weighed. Six heads per plot were
sampled and cut longitudinally through the core and inspected for density.
Cabbage yields ranged from 740 50-lb crates for 'Red Dynasty' to 1361 50-lb crates/acre for 'Atlantis' (able 1). Yields of nine other
entries were not different from those of 'Atlantis'. The proportion of heads harvested varied from 79% for 'Red Dynasty' to 99% for
'Atlantis', 'Pruktor' and 'Green Cup'. Yields in this trial were similar to those obtained in 2000-2001 at this location and 1.2 to 2.2 times
greater than the state average yield of 620 cwt/acre in 2001. Average head weight ranged from 2.7 pounds for 'Red Dynasty' to 4.0
pounds for 'Atlantis'. Accordingly, all entries produced heads that would make 18 or less per 50-lb crate.
Equatorial dimensions were 5.0 inches for 'Red Dynasty' to 6.9 inches for 'Atlantis' Table 2). Polar dimensions varied from 5.8 inches
for 'Ducati' to 7.5 inches for 'Gideon'. 'Blue Dynasty', 'Cardinal', 'Emblem', 'Gideon', 'Gloria', 'Izalco', 'Pruktor', 'Ramada', 'Red
Dynasty', 'Rio Verde', 'Solid Blue 780' and 'Solid Blue 790' had oval heads; 'Ducati' and 'Matsumi' were flat and the other entries were
nearly round. Core length was greatest in 'Emblem' and shortest in 'Matsuma'. Core diameter was greatest in 'Red Dynasty' and least
in 'Atlantis', 'Izalco', 'Cardinal' and 'Red Success'. 'Atlantis', 'Bravo', 'Cheers', 'Ducati', 'Emblem', 'Gideon', 'Gloria', 'Green Cup',
'Izalco', 'Matsuma', 'Pruktor', 'Ramada', 'Rio Verde', and 'Solid Blue 790' are currently recommended for production in Florida.
Table 1. Cabbage seed source, yield, average weight, and days to first harvest. Winter, 2001-2002.
Marketable Yield1,2 Avg Wt r
Entry Source (crates/A) (%) (b)
Solid Blue 790 Abbott & Cobb
Bravo Harris Moran
Blue Dynasty Seminis
Green Cup American Takii
Solid Blue 780
Abbott & Cobb
S 3.4 c-g
S 3.0 gh
)ays to First
1Crate = 50 lb. A = 8712 linear bed feet. Double rows, staggered with 12 in. between plants and 16 in. between
rows. Beds on 5 ft centers.
2As a percentage of plants set.
3From transplant date 27 November 2001.
4Mean separation in columns by Duncan's multiple range test, 5% level.
Table 2. Cabbage head and core dimensions. Winter 2001-2002.
6.9 a3 6.9 c-e
Solid Blue 790
I 6.5 e-g
S 7.0 b-d
S 6.9 c-e
S 7.0 bc
3.1 e-h 1.0 e-g
2.9 f-i 1.3 ab
Blue Dynasty 5.9 g-k 6.6 d-g 0.90 de
Ducati 6.6 a-d 5.8 i 1.14 a
Ramada 5.9 h-k 6.5 e-g 0.91 de
Green Cup 6.3 c-h 6.3 f-h 1.00 bc
Gideon 5.6 jk 7.5 a 0.74 g
Cardinal 6.1 e-i 6.8 c-e 0.89
Red Success 6.0 f-j 6.0 hi 0.99
Solid Blue 780 5.5 k 6.3 f-h 0.87
Red Dynasty 5.0 I 6.3 gh 0.8(
1 From a sample of 6 heads per plot.
2Values <1 = oval shape, 1 = round, >1 = flattened.
3Mean separation in columns by Duncan's multiple range test, 5% level.
GCREC Fall 2001 Tomato Variety Evaluation
In 1999-2000, 43,200 acres of tomatoes were harvested in Florida, yielding 62.2 million 25-pound cartons worth over $418 million.
Tomatoes accounted for almost 30% of the total value for all vegetables grown in Florida during 1999-2000, making it the most
important vegetable produced in the state. The Palmetto-Ruskin area (west-central Florida) accounted for over 36% of the state's total
fresh market tomato production in 1999-2000.
A tomato variety trial was conducted in fall 2001 at the Gulf Coast Research and Education Center-Bradenton located in west-central
Florida to evaluate 31 fresh market tomato varieties and breeding lines in a replicated yield trial.
Seeds were sown on 13 July into planter flats (1.5 x 1.5 x 2.5-inch cells) containing a commercial mix. Transplants were fertilized
periodically with a liquid 20-20-20 (N-P205K20) to sustain growth during production. Plants were conditioned before transplanting by
limiting water and nutrients in the final phase of production.
The land was prepared in early February. Beds were formed and fumigated with methyl bromide:chloropicrin, 67:33 at 350 Ib/treated
acre. Banded fertilizer was applied in shallow grooves on the bed shoulders after the beds were pressed and before the white
polyethylene mulch was applied. The total fertilizer applied was equivalent to 282-0-392 Ib N-P205-K20/A. The final beds were 32-in.
wide and 8-in. high, and were spaced on 5-ft centers with six beds between seepage irrigation/drainage ditches, which were on 41-ft
centers. Transplants were set in the field on 21 August and spaced 24 in. apart in single rows down the center of each bed.
Fruit were harvested at or beyond the mature-green stage on 7-8 and 19-20 November and 3-4 and 14-15 December. Tomatoes were
graded as cull or marketable by U.S. standards for grades and marketable fruit were sized by machine (see table footnotes for
specifications). Marketable fruits of each size were counted and weighed, cull fruits were weighed.
Seasonal yields from four harvests ranged from 1658 cartons/acre for HA 3061 to 3268 cartons/acre for NC 99405. Ten other entries
had yields similar to those of NC 99405. All entries produced yields greater than the state average yield for fall 1999 of 1053
Yields of extra-large fruit varied from 960 cartons/acre for HT-250 to 2516 cartons/acre for 'Sanibel'. Yields of 'Sanibel' extra large fruit
were not different from those of 18 other entries. Large fruit yields ranged from 254 cartons/acre for HT-320 to 847 cartons/acre for NC
99405. Cull fruit for the entire season varied from 11% by weight for EX 1405037 to 33% for HA 3061. Prominent blossom-end nipples,
rough shoulders, and small fruit were the principal defects during the latter part of the season. Average fruit weight was from 5.3 oz for
HT-310 to 6.9 oz for Fla. 7943.
Yields in the fall 2001 season surpassed those in recent fall seasons at this location. This was due in part to four harvests instead of the
usual three harvests. On the other hand, marketable fruit yields were high despite a high proportion of cull fruit. Exceptional
experimental hybrid performers in fall 2001 were NC 99405, HA 3057, Fla. 7943, XTM 0227, TX 99963, PX 150535, and Fla. 7973.
Table 1. Seed source, total marketable yields, average marketable fruit weight, and cull percentages for fresh market
tomato entries in fall 2001. (Harvest Dates: 7-8, 19-20 November and 3-4, 14-15 December 2001).
3268 a3 2158 a-c 847 a
3092 ab 2516 a
505 c-g 71 c-g
2973 a-c 1912 a-e 810 ab 251 ab
2787 a-d 2255 ab 440 d-j 93 e-g
2731 a-e 1940 a-e 649 a-d 142 c-f
16f-k 5.8 i-m
16 g-k 6.5 a-g
20d-j 6.1 c-j
14 i-k 6.9 a
22 c-g 5.9 g-k
1A i L
07na a 1 0074n Ik Ir7 f i
Abbott & Cobb
Abbott & Cobb
Abbott & Cobb
Abbott & Cobb
159 b-e 33 a
1Carton = 25 Ibs. Acre = 8712 Ibf. Grading belt hole sizes: X-Large=no belt, greater than 2.75", Large=2.75"-2.51";
Medium=2.5"- 2.26"; and Cull <2.25".
3Mean separation in columns by Duncan's multiple range test, 5% level.
(Maynard, Vegetarian 02-06)
Sweet Onion Variety Trial, Spring 2002
Sweet (short-day) onions are a relatively minor crop in Florida. Production exists as both dry bulbs (mature) and green tops (immature).
Limited production has existed throughout the state. The biggest deterrent for increased production is from competition from established
markets in south Texas and middle Georgia areas. However, the potential exists for expanding production, especially in the areas of
local sales and direct marketing.
The objective of this trial was to evaluate the performance of sweet onion varieties under northwest Florida conditions.
The transplants for this trial were produced from field beds at the NFREC, Quincy. Fifteen entries were seeded on 1 Oct 2001. Seed
were planted at rate of about 30 seed per ft into rows spaced 12 inches apart. Preplant fertilization of seedbeds was 30-40-401bs/a of N-
P205-K20. Goal 2XL was applied was applied over the top at 1 pt/a after seedlings reached the 2 true leaf stage. Seedbeds were top
dressed once with 34 Ibs N/a. Entries were transplanted into the production field on 10 Jan 2001. Soil type was an Orangeburg loamy
fine sand. Preplant fertilization was 60-80-80 Ibs/a of N-P205-K20. Production scheme was 3 rows spaced 15 inches apart under a 6 ft
tractor and in-row spacing was 4 inches (65,340 plants/a). Goal 2XL at 2 pts/a was applied on soil surface before transplanting and
Dacthal 75 W at 9 Ibs ai/a was applied over the top after transplanting. Nitrogen was applied twice during the season at 50 Ibs N/a each
time. One top dressing of K20 as KCI at 60 Ibs/a was made during the season. Registered pesticides were applied as needed to control
Entries were harvested as they matured, where mature is defined as when about 25% of the tops of an entry had fallen down naturally.
Bulbs were lifted, allowed to dry for a few hours and tops and roots removed. Bulbs were then placed in bushel baskets and dried for 72
hours at 1000 F in large drying rooms. After drying time was complete, onions were removed, allowed to cool down and graded. Grading
consisted of discarding culls (small onions, splits, off color and decayed) and sizing into medium (1.5-2 inches), large (2-3 inches) and
jumbo (>3 inches) categories. Bulbs were then weighed and counted.
Harvest occurred from the period of 24 April to 7 May. Total yields ranged from 738 50 Ib bags/a for 'Sugar Belle' to 118 50 Ib bags/a
for 'PS 7292' (Table 1). Four other entries produced yields as high as 'Sugar Belle'. Yields were good to very poor in 2002. A late freeze
in February did not kill plants but caused a lot of leaf damage which translated to high incidence of bulb rotting at harvest time. The
spring 2002 crop was one of the worst crops of onions produced at NFREC over the past 15 years due to bulb rot. The Vidalia area this
spring had a very high incidence of bulb rot and estimates of crop loss is about 60 %. 'Linda Vista' produced the largest bulb at 11.5 oz
and 'PS 7292' produced the smallest at 8.0 oz. Percent marketable bulbs ranged from a low of 18.3 % for 'PS 7292' to a high of 83.2
% for 'SSC 6436'. Percent bolting level was very low (<1%) on all entries. Days to harvest from transplanting ranged 134 days for 'Sugar
Belle', SSC 6436' and 'Georgia' to 147 days for 'Linda Vista'.
Table 1. Sweet onion variety trial results spring 2002, NFREC-Quincy.
(50 Ib sacks/A)
ouce Marketable Bulb wt. Days to
Entry uLarge Jumbo Total (%) (oz) harvest z
Sugar Belle Shamrock 29.6 by 705 a 738 a 81.5 a 11.1 ab 134 e
RRr .43 Sqhamrnmk 7R 7 a SRS ah R71 ah 8R:1 a 9 9 h-rl 134
Nirvana Sunseeds 39.2 b 602 ab 647 ab 77.6 a 10.2 a-c 140 d
*Granex33 Seminis 38.0 b 585 ab 626 ab 70.6 ab 11.1 ab 145 b
SSC 6372 Shamrock 39.8 b 576 ab 620 ab 79.0 a 10.3 a-c 140 d
Georgia Shamrock 42.4 b 494 bc 544 bc 69.2 ab 9.7 b-d 134 e
Sweet Melissa Sunseeds 48.4 b 373 cd 428 cd 50.1 c 9.6 b-d 142 c
Linda Vista Seminis 30.6 b 380 cd 417 cd 46.2 cd 11.5 a 147 a
Granex7092 Seminis 51.8 b 340 de 396 cd 53.5 bc 9.8 b-d 143 c
Rio Bravo Sunseeds 27.4 b 343 de 375 d 47.1 cd 9.5 b-d 142 c
Savannah Sweet Seminis 33.6 b 331 de 367 dc 46.2 cd 9.9 b-d 143 c
Yellow Granex Imp. Sunseeds 30.1 b 250 d-f 286 de 38.2 cd 9.1 c-e 143 c
Chula Vista Seminis 41.5 b 221 e-g 268 d-f 37.2 c-e 9.9 b-d 143 c
Sweet Melody Sunseeds 34.9 b 177 fg 213 ef 29.2 de 8.6 de 143 c
PS 7292 Seminis 27.9 b 88 g 118f 18.3 e 8.0 e 143 c
z From transplanting.
y Mean separation by Duncan's Multiple Range Test, 5 % level.
(Olson Vegetarian 02-06)
Section 18 for AIM for Tomato, Pepper and Eggplant Row Middles
The Environmental Protection Agency (EPA) has granted a specific exemption under Section 18 of FIFRA for the use of carfentrazone-
ethyl (Aim 2EC) on fruiting vegetables (except cucurbits) to control paraquat resistant nightshade, common ground sel and morning
glory. A total of 20,000 acres of tomatoes,10,000 acres of peppers and 1,000 acres of eggplants may be treated in Florida.
Applications may only be made to row middles of fruiting vegetables by ground application with spray hoods. One to 2 fluid ounces of
Aim 2EC (0.016 to 0.031 Ibs ai/A) per application may be made. Three to 6 applications per season up to 0.076 Ib ai (6 fl. oz. product)
may be made. Allow 14 days between applications. A 1 day preharvest interval (PHI) will be observed. The Section 18 will expire on
May 30, 2003. The exemption was applied and granted through FFVA and the FDACS.
Section 18 for Sandea on Tomatoes
The Environmental Protection Agency (EPA) has granted a specific exemption under Section 18 of FIFRA for the use of halosulfuron-
methyl (Sandea) for the control of purple and yellow nutsedge in tomato. A total of 43,200 acres of tomatoes may be treated in Florida.
A maximum of 0.094 Ibs of active ingredient (ai) or 2 ounces of Sandea 75DF may be applied per acre per year. A total of 2 applications
may be made per acre per year. Applications are to be made using ground equipment. Aerial applications are prohibited. Two
applications of Sandea 75DF may be applied as either:
one pretransplant soil surface treatment of 0.5 to 0.75 ounces Sandea 75DF (0.024 to 0.036 Ibs ai);
one "over-the-top" application 14 days after transplanting of 0.5-0.75 oz. product; and /or
postemergence applications) of up to 1 ounce product (0.047 Ib ai) to the row middles between planted rows of tomatoes may be
A 30-day PHI will be observed. The Section 18 will expire on June 4, 2003.
The Section 18 was applied for and granted through efforts of the Florida Fruit and Vegetable Association (FFVA) and the Florid
Department of Agriculture and Consumer Services (FDACS).
(Stall Vegetarian 02-06)
Extension Veaetable Croos Soecialists
Daniel J. Cantliffe
Professor and Chairman
Assistant Professor, strawberry
Assistant Professor, vegetable production
Elizabeth M. Lamb
Assistant Professor, production
Assistant Professor, soils
Donald N. Maynard
Stephen M. Olson
Professor, small farms
Ronald W. Rice
Assistant Professor, nutrition
Steven A. Sargent
Assistant Professor, vegetable nutrition
William M. Stall
Professor and editor, weed control
James M. Stephens (retired)
Professor, vegetable gardening
Charles S. Vavrina
James M. White
Associate Professor, organic farming
Mark A. Ritenour
Assistant Professor, postharvest
University of Florida
Institute of Food and Agricultural Sciences
Horticultural Sciences Department
Florida Cooperative Extension Service
North Florida Research and Education Center Suwannee Valley
Gulf Coast Research and Education Center Dover
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