Front Cover
 Impact of energy issues on the...
 Potential impact of increased efficiency...
 Research update on grape tomatoes:...
 Nitrogen BMP efforts with tomato...
 Whitefly resistance update and...
 TYLCV-resistant cultivar trial...
 Tomato varieties for Florida
 Water management for tomato
 Fertilizer and nutrient management...
 Tomato fungicides and other disease...
 Selected insecticides approved...
 Weed control in tomato
 Nematicides registered for use...

Title: Florida Tomato Institute proceedings
Full Citation
Permanent Link: http://ufdc.ufl.edu/UF00089451/00004
 Material Information
Title: Florida Tomato Institute proceedings 2006
Series Title: Florida Tomato Institute proceedings
Physical Description: Serial
Language: English
Creator: Cushman, Kent ( Compiler )
Gilreath, Phyllis ( Compiler )
Affiliation: University of Florida -- Immokalee -- Southwest Florida Research and Education Center
Publisher: Gulf Coast Research and Education Center. Institute of Food and Agricultural Sciences, University of Florida
Place of Publication: Wimauma, Fla.
Publication Date: 2006
 Record Information
Bibliographic ID: UF00089451
Volume ID: VID00004
Source Institution: University of Florida
Rights Management: All rights reserved by the source institution and holding location.


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Table of Contents
    Front Cover
        Front Cover
        Page 1
    Impact of energy issues on the Florida tomato industry
        Page 2
        Page 3
        Page 4
        Page 5
        Page 6
        Page 7
    Potential impact of increased efficiency in harvesting and packing of fresh tomatoes
        Page 8
        Page 9
        Page 10
        Page 11
    Research update on grape tomatoes: varieties, taste tests and response to N rates
        Page 12
        Page 13
        Page 14
        Page 15
    Nitrogen BMP efforts with tomato production in Florida in the 2005-2006 season
        Page 16
        Page 17
        Page 18
        Page 19
        Page 20
        Page 21
        Page 22
        Page 23
    Whitefly resistance update and proposed mandated burn down rule
        Page 24
        Page 25
        Page 26
        Page 27
        Page 28
    TYLCV-resistant cultivar trial and whitefly control
        Page 29
        Page 30
        Page 31
        Page 32
        Page 33
        Page 34
    Tomato varieties for Florida
        Page 35
        Page 36
        Page 37
        Page 38
        Page 39
    Water management for tomato
        Page 40
        Page 41
        Page 42
        Page 43
        Page 44
    Fertilizer and nutrient management for tomato
        Page 45
        Page 46
        Page 47
        Page 48
        Page 49
        Page 50
    Tomato fungicides and other disease management products
        Page 51
        Page 52
        Page 53
        Page 54
    Selected insecticides approved for use on insects attacking tomatoes
        Page 55
        Page 56
        Page 57
        Page 58
        Page 59
        Page 60
        Page 61
        Page 62
        Page 63
        Page 64
        Page 65
    Weed control in tomato
        Page 66
        Page 67
        Page 68
    Nematicides registered for use on Florida tomato
        Page 69
Full Text



: I

Ritz Carlton Naples, Florida September 6, 2006 PRO 523

Moderator: Gene McAvoy, Hendry County Extension Service
9:00 Welcome and Opening Remarks
George Hochmuth, Associate Dean for Research, Gainesville
9:10 "State of the Florida Tomato" Address
Reggie Brown, Florida Tomato Committee, Orlando
9:20 Methyl Bromide CUE Status for 2007 and Beyond
Mike Aerts FFVA, Orlando
9:40 Food Safety and the Florida Tomato Industry
Martha Roberts, UF/IFAS, Gainesville
10:00 Impact of Energy Issues on the Florida Tomato Industry
John VanSickle, UF/IFAS, Gainesville ............... ..................... pg. 2
10:20 Labor Challenges for the Florida Tomato Industry
Walter Kates, FFVA, Orlando
10:40 Potential Impact of Increased Efficiency in Harvesting and Packing of Fresh Tomatoes
Steve Sargent, UF/IFAS, Gainesville ................ ...................... pg. 8
11:00 Research Update on Grape Tomatoes: Varieties, Taste Tests and Response to N Rates
Eric Simonne, UF/IFAS, Gainesville .................................... pg. 12

11:20 Lunch and Visit Sponsor Information Tables

Moderator: Alicia Whidden, Hillsborough County Extension Service, Seffner
1:00 Nitrogen BMP Efforts with Tomato Production in Florida in the 2005-2006 Season
Monica Ozores-Hampton, UF/IFAS, SWFREC, Immokalee ...................... pg. 16
1:20 Whitefly Resistance Update and Proposed Mandated Burn Down Rule
Dave Schuster, UF/IFAS, GCREC Wimauma .............................. pg. 24
1:40 TYLCV-Resistant Cultivar Trial and Whitefly Control
Kent Cushman, UF/IFAS, SWFREC, Immokalee ........................... pg 29
2:00 New Product Updates
Industry Representatives
3:00 Adjourn and Visit Information Cafe

Tomato Varieties for Florida Selected Insecticides Approved for Use on Insects
Stephen M. Olson, NFREC, Quincy, and Eugene Attacking Tomatoes
McAvoy, Hendry County Extension, LaBelle.. pg. 35 Susan E. Webb, Entomology and Nematology Dept.,
UF, Gainesville ............................. pg. 55
Water Management for Tomato
Eric. H. Simonne, Horticultural Sciences Dept., Weed Control in Tomato
UF, Gainesville .... ...................... pg. 40 William H. Stall, Horticultural Sciences Dept.,
UF, Gainesville; James P. Gilreath, UF, GCREC,
Fertilizer and Nutrient Management for Tomato Wimauma ............................ pg. 66
Eric H. Simonne, Horticultural Sciences Dept.,
UF, Gainesville ............................ pg. 45 Nematicides Registered for Use on Florida Tomato
Joseph Noling, UF, CREC, Lake Alfred ......... pg. 69
Tomato Fungicides and Other Disease
Management Products
Tim Momol and Laura Ritchie,
NFREC, Quincy .......... ............... pg. 51

Impact of Energy Issues on the Florida
Tomato Industry

John J. VanSickle and Santiago Bucaram1

Food & Resource Economics, IFAS, University of Florida
and Executive Director of the International Agricultural
Trade and Policy Center \i,, i,,. Bucaram is a graduate
student in the Food & Resource Economics Department.

sickle @ufl.edu

The rise in energy prices over the last 4 years has had
significant impacts on horticultural growers. Inputs ranging
from fertilizer to fuel increased in price and increased the cost
to provide product to consumers. Rising input costs generally
increase the cost of production for all growers because no grower
is generally large enough to influence the price of an input or able
to alter their production practice enough to offset the rising cost
of the input. One would expect rising input costs to impact all
growers the same if they employ similar production technologies.
Economic theory would suggest that increasing costs will force
some growers out of business and result in higher prices for those
growers remaining in business. Consumers will be forced to pay
more for less product supplied to the market.
Since the end of 2002, U.S. retail diesel prices have been
generally increasing, with a maximum of $3.15 per gallon in
October, 2005 as a result of Hurricane Katrina further tightening
supplies (figure 1). But the hurricane is only one factor, albeit a
dramatic one, which has caused diesel prices to rise in 2005.
A major factor influencing diesel prices in 2005 was the
increase in crude oil prices. The price of West Texas Intermediate
(WTI) crude oil, which started the year at about $42 per barrel,
reached $70 per barrel in early September. Crude oil prices
rose throughout 2004 and 2005 as global oil demand increased
dramatically, stretching capacity along the entire oil market
system. With minimal spare capacity in the face of the potential
for significant supply disruptions from numerous sources, oil
prices were high throughout 2005.
In addition, Hurricane Katrina had a devastating impact
on U.S. diesel markets, initially taking out more than 25 percent
of U.S. crude oil production and 10-15 percent of U.S. refinery
capacity. On top of that, major oil pipelines that feed the Midwest
and the East Coast from the Gulf of Mexico area were shut down
or forced to operate at reduced rates for a significant period. The
result was a 94 percent increase in diesel prices over the 2002 to
2005 period.
Increased input costs influence competitiveness if one
producing area employs more of the input in the process of
producing and marketing the product. Rising energy prices are
likely to result in only slight changes in comparative advantage for
production costs on the farm, but should have significant impacts
on the cost of getting a product to market. It is expected that those
producers closer to the market will gain comparative advantage as
the cost of delivering the product to consumer markets increases
more for those producers at greater distance from the market. If
diesel price increases are sustained, it would be expected that the

comparative advantage of some producing areas will change.
Some producing areas should increase market share as others lose
market share to more efficient suppliers. The objective of this
research is to estimate the impact a sustained increase in fuel cost
is expected to have on the U.S. vegetable market, with particular
attention paid to Florida tomato growers.

A model of the North American vegetable market was
developed by VanSickle et al. (2000) to estimate the impacts of
a ban of methyl bromide on producers and consumers of fresh
vegetables in North America. The North American vegetable
model can be characterized as a spatial equilibrium problem.
The model is limited to those crops that used methyl bromide as
a pre-plant fumigant and those crops that are competitive with
crops that used methyl bromide. Crops included in the model were
tomatoes, peppers, eggplant, cucumbers, squash, watermelons,
and strawberries. Producing areas included were Florida, Mexico,
California, Texas, South Carolina, Virginia, and Maryland
combined, and Alabama and Tennessee combined. Florida was
separated into four producing areas: Dade County, Palm Beach
County, Southwest Florida, and West Central Florida (Palmetto-
Ruskin area). Mexico was included with two producing areas: the
Mexican states of Sinaloa and Baja California. California was
separated into two producing areas for strawberries: Southern
California (including Orange, Ventura, San Diego, and Los
Angeles Counties) and Northern California (the remaining
California production). California fresh tomatoes were modeled
as a single producing area.
The U.S. vegetable model allocates production of these
crops across regions based on their monthly cost delivered to
regional markets; productivity and the regional demand structure
for fresh vegetables in the U.S. market. Inverse demand equations
were employed inthe model based on work by NaLampang (2004).
Preharvest and postharvest production costs were estimated
for each production system and area included in the model.
Transportation costs were included for delivering these products
to each of the regional markets based on mileages determined by
the Automap software and an estimate of $1.3072 per mile as the
transportation cost of a fully loaded refrigerated truck carrying
40,000 pounds of product (VanSickle et al., 2002).
The model was solved using GAMS programming
software. The analysis of impacts from increases in energy prices
was conducted in two parts. First, the model was solved with
parameters that assumed energy prices remained constant at the
2002 level. This solution provided the baseline for comparison to
other solutions where the parameters for energy prices in the model
were adjusted to reflect increased fuel costs 94 percent higher than
those of 2002. Two scenarios beyond the baseline were solved
with the model. The first scenario assumed that production shifts
would be unconstrained and that production would move to those
areas that held a seasonal comparative advantage in producing
and marketing these crops. The second scenario assumed that acres
devoted to production of fresh vegetables in Dade County would be
constrained to acres produced in 2002. Discussions with growers
suggested that urbanization in Dade County, water restrictions and
labor availability constrains acreage available to vegetable crops.

The solution to the quadratic programming model included
equilibrium prices and quantity consumed by month and crop in
each of the four market areas, shipments by month and crop from
each producing area to each market, and the acres planted to each
cropping system in each producing area. The baseline solution
performed reasonably well in replicating the observed pattern of
shipments and acres planted for the 2001/02 production season.
The acres planted by cropping system in each of the
producing areas for the baseline model are shown in table 1.
Total acreage that is planted to tomatoes in Florida in the baseline
model is 42,240 acres, which is slightly less than the 45,000 acres
reported by the FloridaAgricultural Statistics Service for the 2002
season. The total baseline acreage of U.S. tomatoes is 89,351,
which is within eight percent of the total acreage actually planted
in all of the domestic producing areas included in the model for
2002. The baseline acreage of each of the other crops was also
estimated within five percent of the actual acreage reported for
the 2002 season.

The model was adjusted to reflect the increased cost of
delivering products from each of the growing areas into each of
the consuming markets. The model was adjusted to reflect the
higher cost of transporting product to market from each of the
producing areas by inflating the delivery cost by 94 percent. The
first scenario in tables 1 3 assumes that acreage would adjust
based on the changing competitiveness of the producing areas
with no constraints placed on any one producing area. The second
scenario in tables 1 3 assumes that total Dade County acreage
in tomatoes and squash is constrained to the total acreage in
production in 2002, but that adjustments were allowed between
tomatoes and squash.
The results of the first scenario suggest that higher fuel
prices have made Florida more competitive in the NorthAmerican
vegetable market. The results suggest that tomato acreage inFlorida
will expand from 42,240 acres to 59,383 acres, an increase of 40
percent (table 1). This total acreage approaches the high of 62,500
acres planted in 1989. The structure of the Florida tomato business
would be expected to change significantly under this scenario
with Dade County expanding tomato production to 35,189 acres.
The Palmetto Ruskin producing area also expands from 13,233
acres to 15,660 acres. Palm Beach County and southwest Florida
decline with southwest Florida declining from 19,915 acres to
5,949 acres. The results suggest that if higher energy prices are
sustained and no adjustments in delivery practices offset those
increased costs, then Florida's tomato industry will increase as
they gain competitive advantage over other U.S. and Mexican
producing areas. Concurrent with this increase in acreage is an
increase in market share for Florida and other east coast suppliers
(table 2). Total shipping point revenues for these crops increase in
Florida with the exception of southwest Florida where production
and production value fall (table 3). California and Mexico are the
largest losers of production, market share and value.
The results suggest that Florida will gain market share at
the expense of Mexico and California. Higher energy prices that
result in higher delivery costs of 94 percent for Mexico will cause

Mexico to lose with tomato acreage falling from 38,812 acres in
Sinaloa to 11,331 acres. However, acreage in Baja California will
increase from 3,526 acres to 8,044 acres. Increased acreage in
Baja California is drawn in as California loses the eastern U.S.
summer market to east coast suppliers (Alabama and Tennessee).
Pressure from the east coast will put pressure on California
and allow Baja California to become more competitive over the
course of the season. The results suggest that California will
struggle to maintain competitiveness, with the model suggesting
no commercial fresh tomato acreage planted if higher energy
prices are sustained without any offsetting technology adoption.
The results suggest that California and Sinaloa Mexico will be
the largest losers with south Florida, Alabama and Tennessee
suppliers gaining market share.
The second scenario assumed that Dade County would be
unable to expand beyond the total acreage devoted to these crops
in 2002. If that constraint holds then Dade County is expected
to increase tomato acreage at the expense of squash production
in Dade County. In the scenario, Dade County expands tomato
production to 7,910 acres, a 111 percent increase in acreage. That
increase comes at the expense of squash production. Constraining
expansion in Dade County also spares the other producing areas
as the Palmetto Ruskin producing area becomes the dominant
supplier with 30,715 acres.

The results of the analysis suggest that increases in fuel
costs have helped the competitive position of Florida and other
east coast suppliers at the expense of Mexico and California
producers. These results are not all that surprising. An increase
in fuel costs of 94 percent should make it more expensive for
California and Mexico to get product into the large northeast
markets. Because the harvest of fresh market tomatoes can take
place over several harvests (weeks), increases in one production
area will impact other producing areas even if the bulk of their
harvest would occur in other market windows. Florida should be
expected to gain ground against Mexico and higher energy prices
will impact Mexican producers more as they battle for the winter
fresh tomato market. As Florida production increases, it will also
impact supply in the fall, winter and spring market windows. The
fall and spring periods have historically been good markets for
California. It is the dynamic nature of the fresh vegetable market,
harvesting product over several weeks of the season, that causes
the competitiveness of the market to change so drastically. The
loss of profitable markets in the fall and spring market windows
will make it more difficult for California to maintain market share
in the summer market window. Unless technologies change or
energy prices decline relative to other costs, it would be expected
that Florida would regain some of its prominence in the market
that it had in 1989 when it produced 62,500 acres of tomatoes.
The reader is cautioned about the results of this model.
The results assume that growers are able to make adjustments
in planting decisions as changes in competitiveness occur.
Some resources are fixed however and it may be difficult to
adjust acreage in response to these changing market conditions.
Packinghouses require a certain volume of product to remain
efficient and packinghouse owners may encourage production to

keep facilities open over short durations to see if adjustments occur
in the market. Also, some areas will be constrained in expansion
because certain resources may not be able to be added. The results
can be used however, to gain insight on where expansion may
occur. If current energy prices are sustained, east coast producing
areas are expected to increase there presence in the market at the
expense of foreign suppliers and California. Florida would also
benefit from this situation.

Sikavis NaLampang. 2004. "Impact of Selected Regulatory
Policies on the U.S. Fruit and Vegetable Industry." Unpublished
Ph.D. Dissertation. Food & Resource Economics Department.
University of Florida.

John J. VanSickle, Charlene Brewster, Thomas H. Spreen. 2002.
"Impact of a Methyl Bromide Ban on the U.S. Vegetable Industry."
EDIS 333. Florida Cooperative Extension Service, Institute of
Food and Agricultural Sciences, University of Florida.

Table 1. Planted acres by crop and producing area in the baseline model and with a 94% increase in delivery costs under
alternative assumptions for Dade County, Florida.

PPPRS 8,3562 10,6861 5 127.6 142331 190423 14233.1
UASH 8,0761 7783 0 80761 7,783 0
EGGPLANT 3,9229 9 2,6783 3,9229 2,6783
STRAWBERRIES 36237 11,8970 8,6369 3,6237 20534 0
CUCCUMBERS 8,8694 8-8694

TOIMATOES 35.18908 2,58358 15,66072 5,94962 4234484 3,36130 1133148 804424 59,383 0 1937572
PEPPERS 8,9354 98746 14614 9,6521 188100 9,6521
SQUASH 53507 9939 5,3507 6,9939
EGGPLANT 2,8114 19900 2,8114 1,9900
STRAWERRIES 52872 7,7139 3,0570 5,2872 107709
CUCCUMBE RS 4,030 3 -4,030 3

iATE 7,910 66 2,625 66 30715 80 10,29080 42,380 14 3,34417 14,232.24 7633.88 51,54292 21 866 12
EPPERS 89483 9,8440 14625 9651 9 18,7923 9651 9
SU 38973 7,1632 3,8973 71632
EGGPLANT 2 8114 19900 28114 1,990 0
TRAWERIS 52872 7,7139 3,0570 5,2872 107709
CUCCUMBERS 4,030 3 4,030 3

1. Florida: Dade County (DADE), Palm Beach County(PB), Southwest Florida (SW), and West Central Florida (Palmetto-Ruskin P-R),
Texas (TXS), South California (SCA), North California (NCA), Alabama Tennessee (ALTN), South Carolina(SOCA) Virginia Maryland
(VAMD) Sinaloa (MEX1), Baja California, (MEX 2).

2. Scenario 1: Dade County is not constrained in total acreage. Scenario 2: Dade County is constrained its total acreage to that show in
the baseline.

Table 2. Average percent market share by crop and producing area in the baseline model and with a 94% increase in delivery
costs under alternative assumptions for Dade County Florida.

Tomatoes 2.90% 4.10% 9.90% 15.40% 0.00% 18.30% 0.00% 0.70% 4.30% 2.10% 39.00% 3.40
Peppers 0.00% 27.30% 31.70% 0.00% 9.10% 0.00% 0.00% 0.00% 0.00% 0.00% 31.90% 0.00%
Cukes 0.00% 49.40% 0.00% 0.00% 0.00% 0.00% 0.00% 0.00% 0.00% 0.00% 50.60% 0.00%
Squash 51.90% 0.00% 0.00% 20.20% 0.00% 0.00% 0.00% 0.00% 0.00% 0.00% 27.90% 0.00%
Eggplant 0.00% 62.60% 0.00% 0.00% 0.00% 0.00% 0.00% 0.00% 0.00% 0.00% 37.40% 0.00%
Melon 0.00% 0.00% 32.20% 67.80% 0.00% 0.00% 0.00% 0.00% 0.0000% 00% 0.00% 0.00%
Straw 0.00% 0.00% 15.10% 0.00%00% 0% 59.80% 25.00% 0.00% 0.00% 0.00% 0.00% 0.00%

Tomatoes 33 80, 2 50". 14 50- 5 70'. 000''.. 000". 0 no0,. 1. :0' .. 00 ". 1 60-.. 14 20. 9 50,
Peppers 00-.; 35 0' : 35 401' 00'.: 3 10. 000... 00". 000 00 0".. 0000 2 20;-. 000-
Cukes 0 00 59 30": 000: 0 O0 0 00.. 0000".. 000 .. 000' 0 0"., 0 ".'. 40 70 0 00..
Squash 45 50 0 00" 000 21 40' 000 .. O 00".. 00 Jo,. 000'. 100". 0 00 .. 3 10: 0 00'.,
Eggplant 0 00.1 1 70 0 00. 00a .:. 0 00". 0 00".. 0 00". 0 00': 000".. 000'. :33 30".. 000'
Melon 0 00. 0 00' 79 10':. 2090'. 000".. 000".. 00 .. 0 000 0 '.. 000... 000 '..
Straw 0 00', 000- 31 -0':'. 00': 000'.. 55 60.. 12 70,. 000' 000.. 000O 0 00. 000',

Tomatoes 8.00% 2.60% 29.90% 10.40% 0.00% 0.00% 0.00% 19.20% 0.00% 1.70% 18.70% 9.50%
Peppers 0.00% 35.30% 35.30% 0.00% 3.10% 0.00% 0.00% 0.00% 0.00% 0.00% 26.20% 0.00%
Cukes 0.00% 59.40% 0.00% 0.00% 0.00% 0.00% 0.00% 0.00% 0.00% 0.00% 40.60% 0.00%
Squash 36.00% 0.00% 0.00% 27.20% 0.00% 0.00% 0.00% 0.00% 0.00% 0.00% 36.80% 0.00%
Eggplant 0.00% 61.70% 0.00% 0.00% 0.00% 0.00% 0.00% 0.00% 0.00% 0.00% 38.30% 0.00%
Melon 0.00% 0.00% 48.60% 51.40% 0.00% 0.00% 0.00% 0.00% 0.00% 0.00% 0.00% 0.00%
Straw 0.00% 0.00% 31.70% 0.00% 0.00% 55.60% 12.70% 0.00% 0.00% 0.00% 0.00% 0.00%

1. Florida: Dade County (DADE), Palm Beach County(PB), Southwest Florida (SW), and West Central Florida (Palmetto-Ruskin P-R),
Texas (TXS), South California (SCA), North California (NCA), Alabama Tennessee (ALTN), South Carolina(SOCA) Virginia Maryland
(VAMD) Sinaloa (MEX1), Baja California, (MEX 2).
2. Scenario 1: Dade County is not constrained in total acreage. Scenario 2: Dade County is constrained its total acreage to that show in
the baseline.

Table 3. Total Revenue for each state for the baseline model and with a 94% increase in delivery costs under alternative
assumptions for Dade County Florida.

















(change in revenues $1,000)








$ 74,720.86
$ 32,222.66
$ (47,064.80)
$ 225,378.90
$ (135,815.90)

$ (17,141.28)

$ (480,119.53)

$ 239,262.03

$ (75,880.67)

$ (15,143.80)

$ (310,630.65)

Parentheses contain negative numbers.
1. Scenario 1: Dade County is not constrained in total acreage. Scenario 2: Dade County is constrained its total acreage to that show in
the baseline.

Figure 1. Weekly U.S. retail diesel prices, August 12, 2002 to February 12, 2006



3 1.5




o o 0 0 0 0 0 0 0 0 0 0 0 0 0 0 0 0
Sa 4 a S6i a a ei 8

Source: Energy Infomation Administration


Potential Impact of Increased
Efficiency in Harvesting and Packing
of Fresh Tomatoes

Steven A. Sargent', John J. VanSickle2 and
Santiago Bucaram2

'Horticultural Sciences Department, P.O. Box 110690
2Food & Resource Economics Department, P.O. Box
110240 University ofFlorida, Gainesville FL 32611


Tomatoes are the largest vegetable crop grown in Florida,
accounting for almost 1/3 of the total value sold. In the 2004 and
2005 seasons, tomatoes were harvested from 42,000 acres and
were worth $500 million and $805 million, respectively USDA
NASS, 2006.). However, tomato production costs continue to
increase, averaging $11,600/acre, up by almost 40% from 2001
(FTC, 2006; Maynard and Olson, 2001). Therefore, our growers
are continually seeking ways to reduce those costs. The harvest
operation accounts for about 30% of total production costs and
therefore amounts to about $167 million for Florida growers.
Reducing net harvest costs by only 10% would translate to about
$17 million annual savings for the industry.
In a 2003 study funded by the Florida Tomato Committee,
Sargent identified several commercially available continuous,
harvest-aid systems that utilize one or two conveyors; the harvest
crew walks behind the unit. There are three general types of
systems, a tractor-mounted system, a welf-pitplelled conveyor
belt system and a mobile field-packing unit. With each of these
systems the crop is harvested into field buckets and carried to the
The tractor-mounted system is designed for smaller
operations. The single conveyor swings out from the side of the
tractor, and the crop is conveyed over the tractor and loaded into
bins or a gondola. The welfpitplelled conveyor belt system is
powered by an on-board diesel engine and moves ahead of the
picking crew and may cover 18 rows. Tomatoes are moved to the
side, pass over undersize eliminator belts, are sorted and elevated
into bins or a gondola. The mobile field-packing unit is also self-
propelled and has two, swing-out conveyors that bring the product
to the central unit, where it is graded, packed and palletized. It is
intermediate in size.
We conducted timing studies and found that harvest was
more efficient with the conveyor systems than with the current
harvest system because the crews required less time to dump the
buckets and return to the place where they were picking. We timed
individual pickers with the self-propelled conveyor belt system
and found that it required from 100 to 120 seconds to harvest a
bucket, walk to the conveyor, and return to the picking location.
With a conventional operation, pickers required from 147 to 181
seconds for these operations. Comparing these values, harvest time
potentially could be shortened up to 50% using the continuous
harvest system, significantly reducing costs for three postharvest
operations: harvest labor, transportation to the packinghouse and

packing operations. Transportation to the packinghouse would
become more efficient due to the capability for presorting in
the field, thereby reducing the amount of out-of-grade tomatoes
shipped to the packinghouse. With fewer out-of-grade tomatoes
hauled to the packinghouse, less labor would be required for
sorting and grading, and fewer culls would require disposal.
The first step in analyzing this system was to perform a
sensitivity analysis to determine how reduction in harvest costs
would impact market share, production, acreage and revenues for
major tomato growing areas shipping to east coast markets. These
results are presented in this paper.

Although 30% to 40% reductions in harvest labor have been
reported by companies using harvest aids, we selected reductions
of 10% and 20% for this analysis to account for added capital and
operating costs of the new harvest aid.
For this analysis the model of "North American Vegetable
Market" was used in order to estimate the impacts of increments
on efficiency in the harvesting and packing of fresh tomatoes.

This model, developed by VanSickle (2000), was built in order
to calculate the impacts of a ban of methyl bromide on producers
and consumers of fresh vegetables in North America. At the same
time, this model was based on the inverse demand system for
the fresh vegetable market developed by Scott (1991). Later on,
Nalampang (2004) expanded these models and refined the process
which was utilized in this current study.
This model can be defined as a spatial equilibrium model
and is limited to a group of crops: tomatoes, peppers, eggplant,
cucumbers, squash, watermelons and strawberries. In this report
only data for tomatoes are reported. The following producing areas
were chosen for the model: Florida, Mexico, California, South
Carolina, Virginia and Maryland combined, and Alabama and
Tennessee combined. Florida was separated into four producing
areas: Dade County, Palm Beach County, Southwest Florida, and
the Palmetto/Ruskin area (West Central Florida). California was
divided in Southern California (Orange, Ventura, San Diego and
Los Angeles counties) and Northern California. Two Mexican
production areas were also included, Sinaloa and Baja California.
Growing seasons were analyzed based on one crop for Dade and
Mexico (late fall to early spring) and California (summer). Spring
and fall crops were analyzed for the other three Florida production
The US vegetable model allocates production of these crops
across regions based on their delivery costs to regional markets,
productivity and the regional demand structure. As previously
stated for this work, a system of inverse demand equations was
used, based upon work by Scott (1991). A Rotterdam model was
also implemented. This model is derived from the problem of a
consumer that is maximizing a utility function u(q) subject to
a budget constraint p' q = m, where m is total expenditure (or
full income), p is a price vector and q a vector of goods. In this
specific case the model is composed of five equations of fresh
vegetable demand in the US, estimated for four selected markets:
Los Angeles, Chicago, Atlanta and New York City.
In order to analyze the impact of increased efficiency in
harvesting of fresh tomatoes and the associated costs, the year 2002

was used as a baseline. Proportional changes in the harvest costs
were applied at a level of -10% and -20% because of increments
in the harvest efficiency. For this analysis other variables were
maintained constant so as to isolate the system from other
phenomena, such as natural disasters, sharply increased energy
prices and demand reallocation.
We optimized this equation system by a process through
which the optimal reallocation of production was provided. This
was executed using GAMS program software so as to determine
the impact of this technology and its consequent contraction
on the harvest costs for the production system. Also, acres
devoted to production of fresh tomatoes in the Dade area were
upper-constrained to acres shown in the baseline, following the
suggestion by growers that acreage available to tomato production
in that county is constrained by urbanization, water restrictions
and labor availability.

Overall, the analyses showed that decreasing harvest
costs by 10% or 20% would give Florida growers a competitive
advantage over other major growing areas. Growers in Mexico
would have substantial losses in market share, production, acreage
and revenues, while California growers would benefit slightly.

Average Market Share. Results showed that for a 10%
decrease in costs, average market share (MS) would increase for
growers in Dade, Palmetto/Ruskin, Southwest and Palm Beach
districts by 1.6%, 3.6%, 0.4% and 0.2%, respectively (Table 1).
A 20% decrease in costs would roughly double the increase in MS
for growers in these districts, with the exception for Palm Beach
district which would decrease by 0.2%. Growers in southern and
northern California and in Baja California, Mexico, would maintain
current MS, while growers in Sonora, Mexico, would lose 5.4%
and 11.4% MS for 10% and 20% lower costs, respectively.

Total Production. Florida production was analyzed by
growing season (single crop, fall, spring) and by production district.
Growers in Palmetto/Ruskin (fall, spring crops) would benefit
most from lower harvest costs, with the spring crop increasing
about two times that of the fall crop for each reduction in harvest
costs (Table 2A). Production for the single crop in Dade would
increase by 60.5% and 121.8% for 10% and 20% reductions in
harvest costs, respectively. Southwest growers would lose 32.8%
production for the spring crop with a 10% decrease in costs, and
8.3% with a 20% decrease, but no effect on the fall crop. There
were no changes for Palm Beach area growers.

Interestingly, while production in the Sinaloa area would
decrease significantly (64.1% and 26.0%), production in the
smaller Baja California area would increase by 116.7% for 10%
but decrease by 38.5% for 20% lower harvest costs in Florida
(Table 2B). Although a small production area, Alabama-Tennessee
growers could lose about 40% production and acreage with a 10%
decrease in Florida production costs, but could realize a 244.5%
increase with a 20% decrease. Production in South Carolina and
Virginia-Maryland would decrease. Production in both California
areas would increase 6.8% with a 20% reduction in costs, whereas

total Mexican production would decrease by 49.1% and 27.0%,
for respective reduced costs of 10% and 20% (Table 2C).

Acreage. Changes in acreage are projected to be virtually
identical with those for total production.

Revenues. Florida has the largest share of revenue ($925
million) of all of the areas in this study, followed by California
($246 million) and Mexico ($712 million) (Table 3). With a 10%
or 20% decrease in harvest costs, statewide revenues could be
expected to increase by 7.6% and 14.8%, respectively; the Dade
and Palmetto-Ruskin areas would benefit most, with increases
ranging from 13.0% to 38.2%.

For the other production areas, there would be minimal
impacts on revenues for California, while a 20% decrease in
costs would have a slightly negative impact for South Carolina
(4.3%), and moderately negative impacts for Mexico (18.7%) and
Virginia-Maryland (25.4%). Again, Alabama-Tennessee would
see an increase in revenues of 244.5%.

This preliminary sensitivity analysis projected that
Florida tomato growers would be much more competitive than
other growing regions if harvest costs were lowered by 10% or
20% due to the implementation of a conveyor harvest system.
Growers in the Palmetto-Ruskin district would benefit most
through increased market share, following by growers in Dade
district. There would be minimal impact on growers in California,
while Mexican growers in Sinaloa state would be most negatively
affected. Further studies will focus on analyzing the cost structure
for implementing these three conveyor systems.

Florida Tomato Committee. Orlando, Florida. hiii
floridatomatoes.org/ (accessed July 2006)

N.Ji .im.. S. 2s 1"14. Impact of selected regulatory policies on the
U.S. fruit and vegetable industry. Unpublished Ph.D. dissertation.
Food & Resource Economics Department, University of Florida,

Olson, S.M., D.N. Maynard, G.J. Hochmuth, C.S. Vavrina,
W.M. Stall, T.A. Kucharek, S.EE. Webb, T.G. Taylor, S.A. Smith
and E.H. Simonne. Ch.41. In, Olson, S.M. and E.H. Simonne
(eds.), Vegetable Production Handbook for Florida 2004-
2005.University of Florida Extension, Gainesville and Citrus &
Vegetable Magazine, Tampa.

Scott, S. W. 1991. International Competition and Demand in the
United States Fresh Winter Vegetable Industry. Unpublished M.S.
Thesis, University of Florida, Gainesville.

VanSickle, J.J., C. Brewster, T.H. Spreen. 2000. Impact of a
methyl bromide ban on the U.S. vegetable industry. Bulletin
333. February. Food and Resource Economics Department.

StevenA. Sargent -Email: sasa@ufl.edu
Horticultural Sciences Department, P.O. Box 110690
University ofFlorida, Gainesville FL 32611

John J. VanSickle Email: jjvansickle@ifas.ufl.edu
Food & Resource Economics Department, P.O. Box 110240
University ofFlorida, Gainesville FL 32611

Santiago Bucaram Email: santibu@ufl.edu
Food & Resource Economics Department, P.O. Box 110240
University ofFlorida, Gainesville FL 32611

Table 1. Average market share for selected tomato growing areas as affected by a 10% or 20% reduction in Florida harvest



Florida Districts
Palm Palmetto/
Beach Ruskin





10% 1.6% 0.2% 3.6% 0.4% -0.4% 0.0%
20% 3.2% -0.2% 7.7% 1.2% 0.3% 0.0%

Reduced Mexico
Harvest Alab- South Virg-
Cost Tenn Carolina Maryl.aloa aja







Table 3. Projected changes in revenues for selected tomato growing areas as affected by a 10% or 20% reduction in Florida
harvest costs.

Baseline Revenue

10% Reduction in Costs
($1,000) (%)
995,393 7.6
90,866 20.1
221,178 1.7
389,850 13.0
293,499 2.2
747,944 0.1
6,926 -40.4
77,540 2.2
37,261 -1.9
663,737 -6.8

20% Reduction in Costs




Palm Beach
South Carolina

Table 2. Projected changes in production and acreage for selected tomato growing areas and seasons as affected by a 10%
or 20% reduction in Florida harvest costs.

Florida Production Districts


Palm Palmetto/ South-
Total Production Dade Beach Ruskin west South North
One Crop 60.5% 0.0% 0.0% 0.0% 0.4% 0.0%
10% Fall 0.0% 0.0% 39.7% 0.0% 0.0% 0.0%
Spring 0.0% 0.0% 68.5% -32.8% 0.0% 0.0%
One Crop 121.8% 0.0% 0.0% 0.0% 6.8% 0.0%
20% Fall 0.0% 0.0% 81.2% 0.0% 0.0% 0.0%
Spring 0.0% 0.0% 129.0% -8.3% 0.0% 0.0%
Total Acreage
One Crop 60.5% 0.0% 0.0% 0.0% 0.4% 0.0%
10% Fall 0.0% 0.0% 39.7% 0.0% 0.0% 0.0%
Spring 0.0% 0.0% 68.5% -32.8% 0.0% 0.0%
One Crop 121.8% 0.0% 0.0% 0.0% 6.8% 0.0%
20% Fall 0.0% 0.0% 81.2% 0.0% 0.0% 0.0%
Spring 0.0% 0.0% 129.0% -8.3% 0.0% 0.0%

Alab- South Virg-
Total Production Tenn Carolina Maryl. Sinaloa Baja Calif.
One Crop -40.4% 2.2% -1.9% -64.1% 116.7%
10% Fall 0.0% 0.0% 0.0% 0.0% 0.0%
Spring 0.0% 0.0% 0.0% 0.0% 0.0%
One Crop 244.5% -4.3% -25.4% -26.0% -38.5%
20% Fall 0.0% 0.0% 0.0% 0.0% 0.0%
Spring 0.0% 0.0% 0.0% 0.0% 0.0%
Total Acreage

One Crop
One Crop






Total Change
Total Production Florida California Mexico
One Crop 60.5% 0.4% -49.1%
10% Fall 39.7% 0.0% 0.0%
Spring 39.8% 0.0% 0.0%
One Crop 121.8% 6.8% -27.0%
20% Fall 81.2% 0.0% 0.0%
Spring 90.1% 0.0% 0.0%
Total Acreage %

One Crop
One Crop




- 11 -

Research Update on Grape Tomatoes:
Varieties, Taste Test and Response to
N Rates

Eric Simonne, Steve Sargent, Amy Simonne,
David Studstill, and Robert Hochmuth

University ofFlorida, IFAS, Horticultural Sciences
Department Gainesville, FL 32611-0690

esimonne@ufl.edu; asim@ufl.edu; bobhoch@ufl.edu

Approximately 2,000 acres of grape tomato are grown in
Florida. Current research efforts aim at identifying best varieties
and developing crop-specific N fertilizer recommendations.

Varieties and taste test. Grape tomatoes have recently
gained in popularity among consumers because they can be eaten
without being cut, they are deep red in color, and their flavor is
intense and pleasant. Most grape tomatoes are of the 'Santa'variety
and are marketed under the "Santa" trade name (Boe et al., 1980).
Because seed availability of 'Santa' is limited, many growers
are looking for a Santa-like variety (Lister, 2000; Sugarman,
2001). The growth, sensory characteristics, and selected chemical
composition of eight red and three yellow commercial varieties
were evaluated in 2004 on tomatoes grown with plasticulture.
Six-week-old transplants of 11 grape tomato varieties
were planted on March 23, 2004 at the North Florida Research
and Education Center Suwannee Valley near Live Oak, FL
on a Lakeland fine sand (Table 1). Tomatoes were grown using
plasticulture on beds spaced 5 ft apart and plants spaced 1.5 ft
apart within the row, which created a stand of 5,810 plants per
acre. Each variety was planted onto three, 23-ft long plots.
Based on soil test results, the field was fertilized with a preplant
application of 13-4-13 (N-P2,O-KO) that supplied 56 kg/ha N (50
lb/acre N) and weekly injections of liquid 7-0-7 according to IFAS
recommendations (Olson et al., 2005). Tomatoes were staked to a
height of 8 ft and strung five times. Fruits began ripening during
early June, but yields were not determined. On June 18, earliness,
the presence of green shoulder on tomato fruits, plant growth
habit, and the occurrence of disease symptoms were recorded by
consensus of two observers.
Chemical analyses were performed by grinding,
centrifuging, and filtering to obtain a clean supernatant of 1.1 lb
samples collected on June 21 from one replication. The supernatant
was then frozen at -22 oF for later analysis. On July 1, supernatant
samples were thawed and total titratable acidity (TTA), soluble
solids content (SSC), and pH were measured according to Roberts
et al. (2002). TTA was determined on a 6-g (0.21 oz) aliquot
by titrating with 0.1 N NaOH to an endpoint pH=8.2 with an
automatic titrimeter. The volume of NaOH used was converted to
milliequivallents (mEq) citric acid/1 OOg fresh juice (%). pH was
measured on the undiluted juice. Soluble solid concentration was
determined with a refractometer.
For the sensory analysis, approximately 2.2 lb of grape
tomato was harvested from each plot from one replication on June

21, washed, dried, and stored overnight at room temperature. The
taste test was conducted the next day between 10:00 and 11:00 am
in a quiet room following the recommendations from theAmerican
Society of Testing Materials (1981). Each volunteer panelist was
seated and received a plate that was divided into five sections
marked with random three-digit numbers. Approval was obtained
from the University of Florida Institutional Review Board for
research involving human subjects under UFIRB-2001-U-770.
Single-fruit samples representing five varieties were placed on
each plate section using tooth picks. Panelists were provided with
a pen, a data collection form, and a glass of water to cleanse their
palate between each sample. On the form, panelists were asked to
provide age group and gender, and were instructed to not report
their names. Panelists were asked to taste each of the five red-
tomato samples and score sweetness, acidity, flavor, and overall
preference. The number of red varieties used in the taste test
was reduced to 5 based on field observations to prevent panelist
fatigue. For each attribute, panelists recorded their scores by
making a mark on a 90-mm (3.0 inch) long, unstructured line with
anchors (Fig.1). Anchors at the left ends of the lines represented
poor scores (such as "not sweet" or "dislike") whereas those on
the right end of the line represented satisfactory scores (such as
"sweet" or "like"). After a short break, new plates and new data
collection forms were provided for the evaluation of three yellow
varieties. The distances from the left sides of the lines to the
panelist's marks were measured to the nearest millimeter to score
each sensory attribute.
'Sweet Olive' was the earliest, 'Chiquita' was pink when
ripe instead of red, and 'Red Grape', 'Sweet Olive', and 'Tami
G' showed no green shoulder (Tables 1 and 2). Ranges for flesh
pH (4.21 to 4.48), titratable acidity (0.31 to 0.50 % citric acid
equivalent), and soluble solids (3.75 to 7.40 oBrix) were narrow,
and similar for all varieties (Table 3). In the taste test, 'Santa' was
consistently rated equivalent to 'Red Grape' and 'St. Nick' while
'Sweet Olive' and 'Tami G' received lower preference scores
(Table 4). Few differences were found among the three yellow
varieties. 'Agriset 8282' and 'Honey Bunch' were preferred over
'Morning Light'.

Grape tomato response to N rates. Current N fertilization
recommendations have been developed for determinate tomato
varieties that have a 3-month long growing season, whereas that
of the indeterminate grape cultivars may be up to six months
Six-week-old transplants were established on Mar. 23, 2005
(0 week after transplanting, WAT) at the North Florida Research
and Education Center Suwannee Valley near Live Oak, FL on
a Lakeland fine sand. Tomatoes were grown on plasticulture as
described above. Fertilization treatments consisted of 0%, 33%,
66%, 100%, 133%, and 166% of the current recommended rate
for round tomato. Treatments were created by applying 25% of N
and KO broadcast preplant in the bed and eight identical weekly
injections of the remaining N from 4 to 11 WAT. This corresponded
to daily injection rates of 3 kg/ha N (2.7 lb/acre N) for the 100%
N rate. Phosphorus and K rates were based on soil test results
and were constant for all treatments. Modifications of the drip
irrigation system allowed for independent fertilizer injections to
plots receiving the different N rates. Each plot was 23 ft long and


was planted in yellow 'Honey Bunch' plants that were not used for
data collection. Marketable yield, culls and soluble solid content
were collected on two red 'Tami G' plants planted in the middle
of each plot. Interplanting a yellow and a red variety allowed for
large plots while minimizing labor needed for harvest. Tomatoes
were staked to a height of 8 ft and strung five times. Irrigation
was applied daily based on plant stage of growth (irrigation length
ranging from 2 x 30 min each day for small plants to 3 x 1.5 hrs
for large plants) in order to maintain soil water tension at the 12
inch depth between 8 (field capacity) and 15 kPa (Simonne et al.,
2005). Other cultural practices followed current recommendations
(Olson et al., 2005).
Plants were harvested weekly five times at the red stage
on June 10, 17, 24 and July 7 and 15 (11 tol6 WAT). The last
harvest also included partially ripe fruits. At each harvest, three
representative tomatoes from each plot were cut in halves and
crushed with a garlic press. The juice was placed on the prism of a
handheld refractometer for the determination of SSC. Petiole sap
NO3-N and K concentrations were determined following current
recommendations (Olson et al., 2005) at first fruit set and first and
third harvests (5, 11, and 13 WAT, respectively).
The experimental design was a randomized complete block
design with four replications. Marketable yield, SSC, and petiole
NO3-N and K concentration responses to N rates were determine
using regression analysis (SAS, 2001).
Season marketable (SMY, kg/ha) and total yield (TY, kg/
ha) response to N rates were quadratic (SMY = -0.16 Nrate + 140
Nrate + 11,821 R2=0.56; CV=32%; TY = -0.18 Nrate2 + 153 Nrate
+ 13949; R2=0.54, CV=32%; both p<0.01; Fig.2). Highest SMY
and TY occurred between 314 and 392 kg/ha N rates (280 and 350
lb/acre N). N rate effect on SMY and TY was significant only for
harvests 4 and 5. SSC ranged from 6.25 to 7.5 oBrix for harvests
1 to 4 and was not significantly affected by N rate. On harvest 5,
SSC tended to be greater with higher N rates. These preliminary
results suggest that N fertilization for grape tomato could be done
by incorporating 56 to 78 kg/ha N in the bed (50 to 70 lb/acre
N), followed by weekly injections of 0, 1.7, 2.3, 2.8, 2.3, 3.0, 3.5
kg/ha/day for 1, 2, 3-4, 5-10, 11-14, and 15-16 WAT, respectively
(0, 1.5, 2.0, 2.5, 2.0, 2.7, 3.1 lb/acre/day). This proposed schedule
needs to be validated under commercial conditions that use
optimal irrigation practices. Because the length of the growing
season for grape tomato may vary, emphasis should be placed on
daily N rates and irrigation management, rather than on seasonal
N rate.

ASTM. 1981. Guidelines for the selection and training of sensory
panel members. ASTM Special Technique Publication 758.
American Society for Testing and Materials, Philadelphia, Pg, 2-

Boe, A.A., PJ. Pelofske, and T.J.Bakken. 1980. 'Santa', 'Gem
State', and 'Benewah' tomatoes. HortScience 15:536-537.

Lister, T. 2000. Shippers relieved by resolution of grape tomato
debate. The Packer Business Newspaper of the Produce Industry.
September 18, p. 4.

Olson, S.M., D.N. Maynard, G.J. Hochmuth, C.S. Vavrina, W.M.
Stall, T.A. Kucharek, S.E. Webb, T.G. Taylor, S.A. Smith, and
E.H. Simonne. 2005. Tomato production in Florida, pp. 357-
375 In: S.M. Olson and E. Simonne (Eds.) 2005-2006 Vegetable
Production Handbook for Florida, Vance Pub., Lenexa, KS.

Roberts, K.P, S.A. Sargent, and A.J. Foxx. 2002. Effects of
storage temperature on ripening and postharvest quality of grape
and mini-pear tomatoes. Proc. Fla. State Hort. Soc. 115:80-84.

SAS Institute. 2000. SAS/STAT Guide for personal computer.
Cary, NC.

Simonne, E.H., M.D. Dukes, and D.Z. Haman. 2005. Principles
and practices for irrigation management, pp. 33-40. In: S.M.
Olson and E. Simonne (Eds.) 2005-2006 Vegetable Production
Guide for Florida, Vance Pub., Lenexa, KS.

Sugarman, C. 2001. Attack of the grape tomatoes. The Washington
Post. hill. .'..I _l.. lp.. I ..in .C./wp-dyn/A12414-2001
SeplI (Accessed April 2005).

- 13-

Table 1. Reported growth habit, and seed source, and observed fruit color, growth habit, green shoulder occurrence, and
comments for selected red grape tomato varieties (all hybrids) grown in 2004 on a Lakeland fine sand near Live Oak,

Variety information

Observations (18 June)

Fruit Growth Fruit Green Disease
Variety color habit' Seed Source color shoulder Comments symptoms
Chiquita Red Det. Johnny's Seeds Pink Yes Unusual color; large fruits None
Jolly Elf Red Det. Siegers Red Yes Poor taste, fair color None
Navidad Red Indet. Rogers Red Some Late maturity; compact growth habit None
Red Grape Red Indet. Johnny's Seeds Red No Good taste; not vigorous None
St. Nick Red Indet. Siegers Red Yes Large fruit, good taste; vigorous None
Santa Red Indet. n/a Red Yes Good taste; vigorous None
Sweet Olive Red Det. Johnny's Seeds Red No Earliest; almost round None
Tami G Red Det. Harris Seeds Red No Nice shape, small fruit None

z Det. = determinate; Indet. = indeterminate; n/a = not commercially available.

Table 2. Reported growth habit, and seed source, and observed fruit color, growth habit, green shoulder occurrence, and
comments for selected yellow grape tomato varieties (all hybrids) grown in 2004 on a Lakeland fine sand near Live
Oak, Fla.

Variety information

Observations (18 June)

Fruit Growth Fruit Green Disease
Variety color habit' Seed Source color shoulder Comments symptoms
Agriset 8282 Yellow Indet. Agrisales Yellow No Late maturity; large fruit, some None
pointed fruits
Honey Bunch Yellow Indet. Stokes Yellow No Small fruit; not vigorous Bacterial spot
Morning Light Yellow Indet. Siegers Yellow Little Uniform cluster, no fruit cracking Bacterial spot
SIndet. = indeterminate

Table 3. Chemical analyses of grape tomato varieties grown on a Lakeland fine sand in 2004.

Soluble solids Total titratable acidity
Variety Color content (Brix) (TTA) (%) Brix:TTA ratio pH
Chiquita Red 5.15 d, 0.50 a 10 4.26 d
Jolly Elf Red 7.40 a 0.49 ab 15 4.41 b
Navidad Red 3.75 e 0.31 f 12 4.27 d
Red Grape Red 5.43 cd 0.40 de 14 4.48 a
St. Nick Red 6.30 bc 0.40 de 16 4.41 b
Santa Red 5.58 bcd 0.46 bc 12 4.35 c
Sweet Olive Red 4.65 de 0.43 cd 11 4.21 e
Tami G Red 6.48 ab 0.41 cde 16 4.48 a
Agriset 8282 Yellow 5.23 d 0.39 de 13 4.24 de
Honey Bunch Yellow 5.33 cd 0.35 ef 15 4.33 c
Morning Light Yellow 4.78 d 0.42 cd 11 4.23 de

'Within columns, mean followed by different letters are significantly different according to Duncan's Multiple Range test at P<0.05.


Table 4. Sensory evaluation of selected grape tomato varieties (Spring 2004).



Overall preference

Red varieties
28 b
32 b
25 b
52 a
47 a
Yellow varieties
33 a
42 a
31 a

Within columns, mean followed by different letters are significantly different according to Duncan's Multiple Range test at P<0.05;
highest and lowest possible scores were 90 and 0 mm, respectively.

Fig.1. Data collection form used for the grape tomato taste test (only 2 samples shown).

2005 NFREC-SV Grape Tomato Variety Taste Test

Gender (Circle one) M F

Circle your age

10-19 20-29 30-39 40-49 50-59 60-69 70-79

Instructions: For each of the red grape tomato samples, rate sweetness, acidity, flavor, and overall preference by making a mark on each
corresponding line. The qualifiers provide the orientation of the lines.

Sample 141 Sample 826
Sweetness: not sweet sweet Sweetness: not sweet sweet
Acidity: dislike like Acidity: dislike like
Flavor: bland flavorful Flavor: bland flavorful
Overall Overall
preference: dislike like preference: dislike like

Fig.2. Marketable yield (kg/ha, 5 harvests cumulated) response of 'Tami G' grape tomato grown with plasticulture in
the Spring of 2005 at the North Florida Research and Education Center- Suwannee Valley, near Live Oak, FL, to
nitrogen rates (yl to y5 represent cumulative yields from up to harvest 1, to up to harvest 5, respectively)



0 78 157 235
Nitrogen Rate (kglha)

314 392

Kg/ha = 0.893 Ib/acre.



41 ab
55 a
29 b
35 b


Red Grape
St. Nick
Sweet Olive
Tami G

Agriset 8282
Honey Bunch
Morning Light

Sars yl = 378 34x + 1206 5
Has 2 3 R =072
o Hares 123 5 y2 =-329 66x2 + 3239 9x + 779 63
- Poly (Harest 234 & 5) R2=089
- -Poly (Harvest 12&3)
- -Line ar(Hes t1)
y5=-1121 2x2 +14514x 1573 . -
R2=086 ,
y4 = -1334 5x2 +14406x 367

SA y3 -1165x2 +10324x- 23818
S-R2 =087
*' ----m

7 5

Nitrogen BMP Efforts with Tomato
Production in Florida in the
2005-2006 Season

Monica Ozores-Hampton', Eric Simonne2, Eugene
McAvoy3, Fritz Roka', Pam Roberts', Phil Stansly',
Sanjay Shukla1, Kent Cushman' Morgan Kelly' Tom
Obreza4, Phyllis Gilreath', Darrin Parmenter6.

'University ofFlorida/IFAS, SWFREC, Immokalee,
FL. 2University ofFlorida, Horticultural Sciences
Department, Gainesville, FL. 3Hendry County Extension
Service. 'University ofFlorida, Soil and Water Science
Department, Gainesville, FL. iManatee County Extension
Service, 6Palm Beach County Extension Service.

Abstract. With the developmentofnutrient bestmanagement
practices (BMPs) for vegetable crops N fertilizer recommendations
must be high enough to ensure maximum economic tomato
yield without detrimentally affecting water quality. The current
statewide UF-IFAS N rate recommended rate of 200 lbs/acre (with
supplemental fertilizer applications under specified conditions)
may need adjustment based on growing season, soil type, and
irrigation system type. The objectives of this project were to
establish partnerships with Florida tomato growers to evaluate N
fertilizer rate effects on yield, plant growth, petiole N sap, water
table depth, and disease incidence. In 2005-2006, we conducted
eight on-farm trials with N rates ranging from 200 to 330 lb/acre.
Each trial included the UF-IFAS and at least one grower-defined
rate. The tomato production was divided in fall, winter and spring
growing seasons based on rainfall and temperature differences,
therefore trials were conducted during those seasons. Nitrogen
rates had no effect on tomato plant biomass except in one drip-
irrigated trial where the IFAS rate produced smaller mature plants
compared with the grower rate. Changes in petiole sap NO,-N and
K concentrations differed between seepage and drip irrigation, but
were above sufficiency thresholds except in one seepage-irrigated
trial. Total tomato yields did not significantly differ between N
treatments except in one seepage/winter trial. After excessive
rain from Hurricane Wilma, additional N application did not
affect yield. Applying more than 200 lb/acre N produced higher
yields of large and medium fruits at third harvest during winter
and spring. However, in some situations lower N rates increased
extra-large fruit yield. A high level of grower engagement created
a popular BMP testing program. Cooperating growers indicated
willingness to continue testing N rates lower than their standard
next year. Tomato yield can fluctuate widely by season and year
due to changing weather conditions. Prices are also volatile,
which creates an unpredictable economic situation. Nitrogen
fertilizer is a minimal production system cost, so growers treat it
as inexpensive insurance. In order to change the grower paradigm,
BMP N rate research must be conducted during all seasons, at
as many locations, and for as many years as possible in order to
identify response trends.

With more than 20,000 acres planted each year in Collier
and Hendry counties, Southwest Florida is an important production
area in the USA for winter fresh-market tomato. Depending on
market conditions, production value ranges between about $150
and $300 million annually. Growing seasons are defined as fall
with planting dates from August to 15 Oct., winter from 15 Oct.
to 15 Dec. and spring from 15 Dec. to 1 Feb. These seasons differ
in rainfall patterns, temperatures and day length. For example,
fall may bring hurricanes, leaching rains, and wide-ranging
temperatures; winter brings cool temperatures and unpredictable
freezes accompanying cold fronts; spring is typically dry with
temperatures cool at the start and warm or hot at the end. Typical
growing season lengths are 18,20, and 16 weeks for fall winter and
spring, respectively. These seasons also differ from a marketing
standpoint. Prices are highest in November-December when fall
plantings are harvested and tend to decrease thereafter.
South Florida tomato cultural practices attempt to maximize
economic return by maximizing productivity. The current UF-
IFAS state-wide N fertilizer rate recommendation for tomato is
based on a 6-ft bed spacing, and consists of base (200 lbs/acre)
and supplemental rates (Olson et al., 2005). For drip-irrigated
crops, 40% of the N and K should be applied preplant and the
remaining injected through the drip system (Dangler and Locascio,
1990; Locascio et al., 1989; Locascio et al., 1997). For seepage
irrigation, 40% ofN and K should be broadcast incorporated in the
bed ("cold mix"), with the rest banded into one or two grooves cut
into the bed surface ("hot mix"). For both systems, supplemental
fertilizer applications are recommended in addition to the base rate
1) after a leaching rain (3 inches in 3 days or 4 inches in 7 days);
2) when the harvest season is extended (crop in the field for more
than 13 weeks); or 3) when leaf or petiole nutrients fall below the
sufficiency range under sound irrigation management (Olson et
al., 2005). Current UF-IFAS drip irrigation scheduling methods
are based on Class A Pan evaporation (Locasio and Smajstrla,
1989) or reference evapotransporation (ETo) (Simonne et al.,
2005). Both methods aim to maintain soil water tension below
10 kPa (Locascio and Smajstrala, 1996). For seepage irrigation,
the water table should be maintained 12 to 16 inches deep during
plant establishment, and 24 to 30 inches deep thereafter (Stanley
and Clark, 2003). Although drip irrigation produced tomato yields
comparable with seep-irrigated production while substantially
improving water-use efficiency (Pitts et al., 1988), seepage
irrigation is still widely used in southwest Florida for economic
reasons (Prevatt et al., 1981).
The "Water Quality/Quantity Best Management Practices
for Florida Vegetables and Agronomic Crop" manual was
jointly developed in 2001-2004 by the Florida Department
of Agriculture and Consumer Services and UF-IFAS (www.
floridaagwaterpolicy.com). BMPs are cultural practices that
maintain productivity while reducing environmental impact. The
BMP manual for vegetables was adopted by rule (5M-6) and by
reference in February, 2006. While the BMP manual recognizes
several nutrient management strategies (including fertilizer rates
that exceed current recommendations), the long-term success of
this voluntary program is based on water quality improvement.
Although N runoff has not been identified as a widespread


problem in south Florida, a concern remains that the combination
of excessive fertilization and irrigation may contribute to elevated
nutrient concentrations in ground and/or surface waters.
Although it has been documented that UF-IFAS tomato
fertilization recommendations are sufficient for maximum yield
(Stanley and Clark, 2003), fertilizerratesusedto produce southwest
Florida tomatoes are typically higher than recommended because
growers believe that UF-IFAS rates are too low and do not provide
enough flexibility to reflect the different growing conditions found
throughout Florida. Because education, demonstration, and direct
grower involvement have been keys to increasing BMP adoption
in north Florida vegetable fields (Hochmuth et al., 2003; Simonne
and Hochmuth, 2003), a 3-year project was initiated in southwest
Florida to 1) establish partnerships with selected tomato growers
to evaluate the effects of N fertilization in commercial fields; 2)
evaluate the effect of N fertilizer rate on plant growth, nutritional
status, yield, disease and pest incidences, and crop market value;
3) determine the optimum N rate for tomato production; and 4)
evaluate the cost effectiveness of selected N application rates.
This paper reports the results of the 2nd year of this project and
focuses on objectives (1) and (2).

We conducted eight trials at five commercial farms to
evaluated tomato response to N fertilizer rates during the 2005-
2006 seasons. Together the cooperating farms represented 16,000
acres (80%) of staked tomato production in southern and eastern
Florida. Soils in the area have a sandy surface layer that is prone
to leaching (Muchovej et al., 2005). Treatments consisted of N
fertilizerratesranging from200 to 330 lb/acreN appliedto seepage-
irrigated tomatoes in a completely randomized experimental
design with three replications (Table 1). In drip-irrigated fields,
there were two individual zones with 12 sub-plots per treatment.
An additional 36 kg ha-' N (32 lb/acre) for trial 1, 125 kg ha-' N
(112 lb/acre) for trial 2 and 67 kg ha-' N (60 lb/acre) for trial 3
were applied after the hurricane Wilma passed through the area
to compensate the loss of N by leaching. At the seepage-irrigated
fields, the UF-IFAS rates were achieved by changing the rate or
composition of the hot mix and by applying custom-made blends
to keep P, K micronutrients rates constant. The trials represented
diverse growing conditions found in Southwest and East Florida,
and also included different varieties (mostly 'Florida 47' and
'Sebring'), plant densities (in-row spacing of 18 to 26 inches
between plants; 5 or 6 ft bed centers), soil types (described above),
and farm sizes (700 to 5,000 acres). Cooperators prepared beds,
fumigated the soil, applied bottom and hot mixes and installed
polyethylene mulch, transplanted, pruned, staked, irrigated and
provided pest and disease control.
Data collection: At 30 days after transplanting (DAT) and
mature plants in two drip-irrigated trial, the shoots of three tomato
plants (fruits removed) selected randomly in each treatment were
collected and oven dried at 65 C until constant weight to determine
dry matter accumulation (Mills and Jones, 1996). The water table
depth was recorded bi-weekly throughout the growing season.
Beginning at first flower buds and continuing until third harvest,
fresh petiole sap NO,-N and K concentrations were measured bi-
weekly using ion-specific meters (Cardi, Spectrum Technologies,

Inc., Plainfield, IL) (Olson et al., 2005). In trial 1, the Fusarium
crown rot caused by the fungus, Fusarium oxysporum f.sp. radicis-
lycopersici first apparent on 12 Jan 05. The number of affected
plants per plot increased through 2 Feb 05, the final reading date
during season 2004-05 season. At the same location in the 2005-
06 season, crown rot symptoms appeared on 10 Jan 06. and the
disease progressed until the final reading date of 2 Feb 06. Plants
in trial 3 were rated for disease severity of bacterial spot caused
by species of the bacteria Xanthomonas, on 2 Jan 06. Six sub-
samples were randomly selected within the treatment plots and
plants were rated visually by estimating the area of symptomatic
leaf tissue.
Harvested plots were 15 to 22 22-ft long row segments of 10
plants. They were clearly marked to prevent unscheduled harvest
by commercial crews. Marketable green and color tomatoes were
graded in the field according to USDA specifications of number
and weight of extra-large (5x6), large (6x6), and medium (6x7)
fruit (USDA, 1997) of green and color. Yield data were subjected
to analysis of variance (ANOVA) mean separation using Duncan's
Multiple Range Test at the 5% level of significance. Disease
severity ratings were examined with ANOVA and treatment
means differences were tested for significance by Tukey's multiple
comparison procedure.
Southwestern Florida tomato growers harvest mature-green
tomatoes in the fall/winter and early spring market windows.
Grower prices for fresh tomatoes are set daily and are sensitive
to market supplies. Imported tomatoes from Mexico, Europe and
Canada compete during the same market windows. In addition,
during many seasons, production from other areas in Florida
overlaps with the southern Florida tomato harvest.
UF-IFAS research has indicated that Florida tomato
growers should be able to achieve maximum economic yield with
200 lb/acre N, but many southwest Florida tomato growers are
extremely reluctant to apply this rate. They believe that a 50 %
increase to 300 lb/acre N is necessary to support higher yield, thus
increasing the likelihood of a favorable economic outcome.
Two economic considerations support grower preference
for higher N fertilization rates. First, N fertilizer represents a
minimal portion of total tomato production cost. Second, it is in
the grower's economic interest to strive for maximum production.
Fresh tomato production is a financially intensive enterprise.
More than $13,000 is required to plant, grow, harvest, pack, and
market one acre of tomatoes. Total fertilization costs (N, P, K,
and micronutrients) are estimated to be less than 3% of total costs
(Smith and Taylor, 2004). In contrast, fertilizer applied by corn
grain farmers in Mississippi represents close to 30% of their total
costs production (Mississippi State University, 2005). Given the
greater relative importance of fertilizer costs, a Mississippi corn
farmer will be much more likely to adjust fertilization rates in
the production budget, a Mississippi corn farmer is more likely to
adjust fertilizer rates than a Florida tomato grower in response to
changes in either commodity or fertilizer prices.
The fresh tomato market is highly volatile. Prices can
change on a weekly or even daily basis. The break-even price for
a southwest Florida tomato grower is estimated to be more than $9
per 25-lb carton (Smith and Taylor, 2004). Clearly, if market prices
are above the break-even point, overall net returns is enhanced

- 17-

with every additional carton that can be harvested and packed.
More interestingly, a grower's goal for maximum production is
just as strong when prices are below break-even but above the unit
cost to harvest, pack, and sell a carton of tomatoes. Within this
range of market prices, each additional box of tomatoes lessens
the total financial loss for that particular field or block. Hence,
under most market conditions, a grower's objective to maximize
production corresponds with his or her economic interests. If
production with 200 lb/acre N is less than with 300 lb/acre N, a
grower is being financially compromised.
The only situations that a lower fertilization rate can be
economically justified are when either the market price is below
the unit cost to harvest, pack, and sell, or when the value of
additional production from an increased N rate does not cover
the added fertilization costs. Given fertilizer costs, market prices,
harvest, and post-harvest costs, one can compute the threshold
production required to economically justify additional N fertilizer.
A graph of yield thresholds is generated from the following
generic equation:

FERT ($/ac) + [HARV ($/ctn) YIELD (ctn/acre)] =
PRICE ($/ctn) YIELD (ctn/acre)

FERT: added cost of additional fertilizer (i.e. nitrogen);
HARV: unit cost to harvest, pack, and market one carton
of tomato;
YIELD: additional yield gained from the additional
application of fertilizer;
PRICE: market price of a sold carton of tomatoes.

Weather conditions and supplemental fertilizer
applications. Hurricane Wilma crossed over south Florida on
October 24, 2005 with 100 miles/h winds and heavy rain. Tomato
stems, branches, leaves, flowers, and fruits were blown from plants
and entire fields were flooded for more than 8 h. Rainfall recorded
by growers during the 2005-2006 season showed accumulations
of 18, 6 and 5 inches for fall, winter and spring, respectively
(Table 2). Local weather variability within a geographical area
can extremely high during the fall particularly as related to the
number of leaching rains. Therefore, is important that growers
have a working gauge installed to record daily rainfall at each
farm location. The IFAS tomato fertilizer recommendation allows
supplemental N and K fertilizer applications in specific situations
(Maynard et al., 2003), as does the BMP manual (Simonne and
Hochmuth, 2003). Under this recommendation, 30 lb/acre of N
can be added for each leaching rain event. Therefore, using fall
2005 as an example, a supplemental application of 90 lbs/acre of
N fertilizer was permissible due to three leaching rains. However,
N fertilizer application rates were 32, 112, and 60 lbs/acre in trials
1,2 and 3, respectively. No fertilizer addition due to leaching rain
was justified during the winter and spring seasons, so N fertilizer
application consisted of the base 200 lbs/acre rate only (Olson et
al., 2005). These results suggest that analysis and prediction of
leaching rain frequency and timing would be valuable for Florida's
vegetable growing areas. Overall, Southwest Florida was hot and

wet throughout the fall, and cool and dry during the winter and
spring of 2005-2006.

Irrigation management The BMP trial acreage was
irrigated 80% by seepage and 20% by drip systems. Seepage
irrigation supplies water to the root zone through upward capillary
movement (upflux) from an artificially-regulated shallow water
table. Since drip irrigation systems supply water to the plant
through plastic tubing installed under the plastic mulch, it is
possible to more precisely control water and fertilizer applications.
The water table in the seepage-irrigated trials fluctuated between
about 16 to 20 inches deep and tensiometer readings were between
4 and 8 kPa. Higher soil moisture and water tables were observed
during the fall season due to hurricane Wilma. In the drip-irrigated
fields, water was applied daily at a volume estimated from the
Weather Service Class A Pan evaporation combined with a crop
coefficient. The water table depth in drip irrigated trials was lower
than in seepage trials, ranging from about 20 to 30 inches. Previous
research with seepage irrigation showed that tomato yield was not
reduced when water table depth was maintained near 20 inches
(Stanley and Clark, 2003). While maintaining a lower water table
resulted in reduced water use in that experiment, water table depth
fluctuations are likely to occur in large fields because the depth of
the restrictive layer supporting the water table may fluctuate in
large fields.

Biomass accumulation. Treatment differences in plant
dry weight 30 DAT for all trials and seasons and final dry weight
biomass in one trial were not significant different. Only in trial 5,
which was drip-irrigated, did the higherN rate produce significantly
greater final tomato plant dry weight than the lower rate. Overall,
N rates had little effect on tomato biomass regardless of sampling
date. This observation contradicts the common concept of judging
crop yield potential by the size and color of the plants.

Plant nutritional status. Petiole sap NO3-N and K
concentrations tended to be above the UF-IFAS sufficiency
threshold throughout the season at all eight locations and under
all N treatments, except for trial 7 where the K was lower than the
sufficiency range. Although the higher N rates produced tomato
sap NO3-N concentrations that were greater compared with
the lower rates, the N nutrition of plants that received either N
rate was "sufficient". Sap data suggest that tomato plants were
sufficient in N and K regardless of N rate despite experiencing a
hurricane, hot and wet weather conditions in the fall, and a cool
and dry condition during winter and spring. Hence, monitoring
NO3-N sap content as a routine monitoring tool does not seem to
be a practical technique and BMP. For drip, irrigation, it may have
a value since fertilizer is injected daily, weekly or bi-weekly, but
it is not practical for a large farm. Both irrigation methods, petiole
sap testing or whole leaf analysis should be used when problems
are suspected.

Disease incidence The plots with the lowest N rate in trial
1 (200 lb/acre) expressed the highest disease incidence with an
average of 53% symptomatic plants in the 2004-2005 season. The
other three treatments (236, 260 or 260 lb/acre N plus biosolids)

- 18-

had 10%, 27%, and 20% average disease incidence, respectively.
In contrast to the 2004-2005, the plots with the highest rate of N
contained the greatest number of affected plants in 2005-2006.
The rate that previously had the most incidences, 200 lb/acre N,
had the lowest incidence of Fusarium crown rot in the 2005-06
season. On 17 Jan 06, significant differences were detected among
treatments for the low rate of N plus compost compared with
the high N rate. However, comparison of treatments by the area
under the disease progress (AUDPC) did not detect significant
differences between treatments. In trial 3, no significant differences
were detected between treatments for the severity of bacterial
spot, which were 19% and 13% disease severity for the grower
and IFAS treatments, respectively. The nutritional status of the
plant can have an impact on susceptibility to certain diseases. In
general, plants containing higher N concentration are associated
with increased susceptibility to diseases caused by Fusarium spp.
That association was not observed in the current study.

Yield response to N rates. There were no significant yield
differences in the first, second, third and total harvests for all size
categories during the fall (P<0.05) (Fig 1). Lack of N response was
probably due to the extra fertilizer applied after hurricane Wilma,
and to the three leaching rains that occurred (Table 2). Higher N
fertilizer rates produced higher yields for large and medium fruits
at third harvest during the winter. Only one trial produced greater
extra-large yield with a lower N rate during the winter. In the
spring, higher N fertilizer rates increased large fruit yield at first
and second harvest, but most of the yield differences were found
in the third and total harvests for all size categories. Only one trial
produced greater total extra-large fruit yields at the lower N rate
during spring. These results illustrate that the 200 lb/acre N rate
produced lower large and medium yield at third harvest compared
with higher rates during a cool and dry growing season. These
results show that it may be possible to reduce N rates especially
when the risk of rainfall is low (winter and spring), or when only
two harvests are expected (late spring). The actual rate needs to be
adjusted based on planting date.

Economical analysis. Figure 2 shows yields that would be
required to pay for an additional 100 lb/acre of N fertilizer across
a range of market prices from $4.50 to $18.50/box of tomatoes.
The additional N is valued at $40/acre to reflect fertilizer costs
during the 2005-06 seasons. Figure 2 further assumes that $3.50
is required to harvest, pack, and market each carton of fruit. As
market prices increase, the yield threshold decreases dramatically.
When market prices are at $4.50/box, an additional 40 cartons of
tomatoes/acre would be needed to cover a $40/acre increase in N
fertilization cost. When the market price increases to $10.50/box,
less than six additional cartons per acre have to be sold before
the added fertilizer cost is covered. Figure 2 demonstrates that
at current costs for fertilizer, harvesting, packing, and marketing,
the yield threshold for an additional 100 lb/acre N fertilizer is
low. Given field variability, it is unlikely that differences in yields
will be able to detect these small amounts. All points above the
yield threshold curve in Figure 2 represent a positive return to
the grower from using 100 additional lb/acre N. However, since
N fertilizer efficiency decreases as rate increases, the unused N

will be left in the field and could potentially cause a water quality
problem if it moves off site.
Data from the second year of the southwest Florida
Nitrogen BMP study have yet to produce conclusive results as
to a presence and/or magnitude of yield differences between
N fertilizer rates. In six trials conducted during the fall, winter
and spring, only one produced statistically significant yield
differences between the 200 lb/acre N recommended rate and a
higher grower-standard rate. In fact, in three of the six trials, total
yields were numerically greater when using the recommended
rate. Of the two trials conducted during spring 2006, one produced
significant yield increases at N rates of 300 lbs /acre. The other
showed that higher N rates produced significantly higher yields
during the second harvest. For total harvest, however, the lower
N rate produced numerically higher yields, but differences were
not statistically significant. Conclusive results describing the yield
effects of various N fertilization rates should not be expected
until several years of data can be pooled together. As the data
accumulate, statistical differences may become more apparent
or a trend may develop. It is important to recognize that yield
variability across seasons will be another economic factor to
consider. In any given year, climate and other growing conditions
may not combine to produce significant yield differences between
lower and higher N fertilization rates. Consequently, the added
fertilizer may in fact depress grower returns. But in another
year, when more favorable growing conditions exist, the added
fertilizer may support significantly higher production. Growers
make fertilization decisions in a state of uncertainty with regard
to seasonal growing and market conditions. The added economic
return during a favorable year may more than offset the costs
incurred during the previous years.
What cannot be incorporated into this analysis is the
environmental risk of excess N leaving the field. Whether N is
an environmental hazard in southwest Florida remains an open
question. However, whether it is a problem or not, environmental
costs are not part of a grower's current decision-making process.
If N proves to be a real environmental threat, then public policy
either through regulation or incentive payments will be needed to
force changes in N fertilization rates beyond the direct impact on
production. Direct monitoring of nutrient movement in and out
of the field may be needed to determine if commercial use of N
rates higher than the BMP standard detrimentally affects off-site
water quality.

Grower participation in the project Growers were highly
engaged in the project and we developed strong successful
partnerships during the 2005-2006 growing season. Growers
provided input in determining fertilizer rates before the season
and helped apply the treatments. We noticed that similar rates
may be achieved by different combinations of cold and hot mix,
and/or different numbers (1 or 2) of hot bands. While for research
purposes it was preferable to refer to each situation as a rate, each
situation represented a different fertilization program. Project
leaders made bi-weekly visits to six trials and weekly visits to two
trials throughout the growing season to discuss progress toward
the goals and to review in-season bi-weekly and weekly progress
reports. These progress reports were farm-by-farm records of sap

- 19-

petiole analyses, water table depth, dry matter accumulation, and
yield. Additionally, growers received a final report at the end of the
season. Although not a direct part of this project, the connection
between irrigation and fertilizer management was discussed.
It became clear that limited irrigation scheduling may be done
when using a seepage system. The constraint of applying all the
fertilizer at the beginning of the season when seepage irrigation
is used increases the potential risk of nutrient leaching. However,
the risk may be reduced if drip irrigation or mixed systems are
Educating farm employees about plant nutrient management
was also an important part of the project. For example, employees
of several farms were trained in the use of ion-specific electrodes
(Cardy meter, Spectrum Technol., Plainfield, Ill.) to monitor sap
NO,-N and K concentrations, and to interpret the results.
In conclusion, results from these second-year trials are
encouraging and indicate that this project is on track to achieve
its objectives.

1. There were no treatment differences in plant dry weight 30
DAP and final dry biomass in all trials, except in trial 5 where
final biomass was higher with higher N rates.
2. Petiole sap NO,-N and K concentrations throughout the season
tended to be above the UF-IFAS sufficiency threshold for all
N treatments in all trials, but differed depending on irrigation
system type.
3. The rate that in previous year had the most incidences, 200
lb/acre N, had the lowest incidence of Fusarium crown rot in
the 2005-06 season.
4. During the fall there were no differences in yield due to extra
addition of fertilizer application to compensate for the loss of
N due to hurricane Wilma. Fertilizer N application greater than
200 lbs/acre produced higher yields of large and medium fruits
at third harvest during the winter and spring season. However,
in some situations lower N fertilizer rates increased extra-large
fruit yield.
5. The optimum N fertilizer rate for tomato is not a simple "one
size fits all". Recommendations should consider irrigation
method (seepage or drip irrigation), growing season (fall,
winter and spring) requiring from 15 to 20 weeks from planting
to harvest.
6. Tomato yield can fluctuate widely by season and year due to
changing weather conditions. Prices are also volatile, which
creates an unpredictable economic situation. Nitrogen fertilizer
is a minimal production system cost, so growers treat it as
inexpensive insurance.
7. A high level of grower engagement created a popular BMP
testing program. Cooperating growers indicated willingness to
continue testing N rates lower than their standard next year.
8. Fertilizerappliedathigherthanrecommendedratestheoretically
increased the risk of negative environmental impact. This
risk needs to be quantitatively assessed, compared with the
economical risk of profit, and possibly reduced through the use
of targeted cost-share programs.

Dangler, J.M. and S.J. Locascio. 1990. Yield of trickle-irrigated
tomatoes as affected by time ofN and K application. J. Amer. Soc.
Hort. Sci. 115(4):585-589.

Hochmuth, R., D. Dinkins, M. Sweat, and E. Simonne. 2003.
Extension programs in Northeastern Florida help growers produce
quality strawberries by improving water and nutrient management,
EDIS HS-956, http://edis.ifas.ufl.edu/HS190.

Locascio, S.J. andA.G. Smajstrla. 1989. Drip irrigated tomato as
affect by water quantity and N and K application timing. Proc.
Fla. State Hort. Soc. 102:307-309.
Locascio, S.J., S.M. Olson, and F.M. Roads. 1989. Water quantity
and time of N and K application for trickle-irrigated tomatoes. J.
Amer. Soc. Hort. Sci 114(2):265-268.

Locascio, S.J. and A.G. Smajstrla. 1996. Water application
scheduling by pan evaporation for drip-irrigated tomato. J. Amer.
Soc. Hort. Sci. 121(1):63-68.

Locascio, S.J., G.J. Hochmuth, F.M. Roads, S.M. Olson, A.G.
Smajstrla, and E.A. Hanlon. 1997. Nitrogen and potassium
application scheduling effects on drip-irrigated tomato yield and
leaf tissue analysis. HortScience 32(2):230-235.

Mississippi State University. 2005. Corn conventional tillage,
non-irrigated 8-row 38" 135 yield goal, Delta Region. Mississippi
State University, Dept. of Agricultural Economics Budget Report
2005-03, December 2005, 81 pages. hliir .. -'...I/

Muchovej.,M, E.A. Hanlon, E. McAvoy, M. Ozores-Hampton,
F.M. Roka, S. Shukla, H. Yamataki, and K. Cushman. 2005.
Vegetable Production on the Sandy Soils of Southwest Florida.
EDIS (In Press).

Olson, S.M., Maynard, D.N., G.J. Hochmuth, C.S. Vavrina, W.M.
Stall, T.A. Kucharek, S.E. Webb, T.G. Taylor, S.A. Smith, and
E.H. Simonne. 2005. Tomato production in Florida, EDIS, HS-
739, http://edis.ifas.ufl.edu/CV137.

Pitts, D.J., G.A. Clark, J. Alvarez, PH. Everett, and J.M. Grimm.
1988. A comparison of micro to subsurface irrigation of tomatoes.
Proc. Fla. State Hort. Soc. 101:393-397.

Prevatt, J.W., C.D. Stanley, andA.A. Csizinski. 1981. An economic
evaluation of three irrigation systems for tomato production. Proc.
Fla. State Hort. Soc. 94:166-169.

Simonne, E.H. and G.J. Hochmuth. 2003. Supplemental fertilizer
application for vegetable crops grown in Florida in the BMP era,
EDIS HS-906, http://edis.ifas.ufl.edu/HS 163


Simonne, E.H., D.W. Studstill, R.C. Hochmuth, J.T. Jones
and C.W. Starling. 2005. On-farm demonstration of soil water
movement in vegetables grown with plasticulture, EDIS, HS
1008, http://edis.ifas.ufl.edu/HS251.

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costs in the Southwest Florida area 2004-2005. University
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Agribusiness, Gainesville, FL. hlip '-" ..I.'li C'.!c.I! !!I .i!!

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Agr. Markt. Serv. liip i' .m 11 ..I.., .>,v/standards/tomatfrh.

Table 1. Experiment number, irrigation type, N rates evaluated, plot size, planting date, and number of harvests in the 2005-
2006 N management trials in southwestern and eastern Florida.

Trial Location/ Irrigation Replication, Planting Number of
number Farm County Season type N rate (Ib/acre)' size (acres) date harvest
1 1 Collier Fall 2005 Seepage 232 to 305, 232+C y 3 (0.17) 19 Sept. 3
2 2 Collier Fall 2005 Seepage 308 and 368 3 (5) 15 Sept. 4
3 5 Collier Fall 2005 Drip 260 and 345 1 (17) 5 Oct. 3
4 2 Collier Winter 2006 Seepage 200 and 260 3 (3) 17 Nov. 3
5 5 Collier Winter 2006 Drip 200 and 300 1 (25) 14 Nov. 3
6 5 Palm Beach Winter 2006 Seepage 200 and 330 3 (1.5) 18 Nov. 3
7 3 Hendry Spring 2006 Seepage 200 and 320 3 (0.83) 4 Jan. 3
8 2 Collier Spring 2006 Seepage 200 and 260 3 (3) 14 Feb. 3

Based on 6-ft spacing
Y C = Yard Waste compost 12 tons/acre

Table 2. Summary of rainfall, number of leaching rain events and possible and applied supplemental N during season 2005-
06 tomato season.

Number of days from Total rainfall Number of Possiblez and applied
Trial Season planting to last harvest (inches) leaching rainfalls supplemental N (Ib/acre)
1 Fall 2005 140 18.2 3 90/32
2 Fall 2005 130 18.2 3 90/112
3 Fall 2005 133 11.3 1 30/60
4 Winter 2006 126 6.2 0 0/0
5 Winter 2006 133 6.1 0 0/0
6 Winter 2006 133 5.0 1 30/0
7 Spring 2006 133 4.5 0 0/0
8 Spring 2006 105 4.4 0 0/0
z UF-IFAS supplemental fertilizer application is allowed after a leaching rain defined as 3 inches in 3 days or 4 inches in 7 days for tomatoes
(Olson et al., 2005)


Fig 1. Effect of N rates on tomato yield during season 2005-06.

Tomato Yields First Harvest
Season 2005-06

First (boxes/acre)
Harvest Trial XL L M Total


150 200 250 300 350
N Rate (Iblacre)

1 230 to 305 ns ns
2 305 vs. 370 ns ns
3 260 vs. 345 (drip) ns ns
4 200 vs. 260 ns ns
5 200 vs. 300 (drip) IFAS ns
6 200 vs. 330 ns ns

7 200 vs. 320
8 200 vs. 260

Tomato Yields Second Harvest
Season 2005-06


* U

A *Fall
A Winter
V ASpring

150 200 250 300 350
N Rate (Ib/acre)

ns ns
ns ns
ns ns

ns ns
ns ns

ns ns ns ns

Trial XL L M Total

1 230 to 305 ns ns
2 305 vs. 370 IFAS ns
3 260 vs. 345 (drip) ns ns
4 200 vs. 260 ns ns
5 200 vs. 300 (drip) ns ns
6 200 vs. 330 ns ns

7 200 vs. 320
8 200 vs. 260

Tomato Yields Third Harvest
Season 2005-06

ns GROWER ns ns

Third (boxes/acre)
Harvest Trial XL L

M Total

1 230 to 305 ns
2 305 vs. 370 IFAS
260 vs. 345

ns ns ns

4 200 vs. 260 ns GROWER GROWER GROWER
200 vs. 300
5 200 vs. 300 ns ns GROWER GROWER
6 200 vs. 330 ns ns ns ns
8 200 vs.260 ns ns ns ns



0 1,000
" 600
>- 400

* U

- 800
. 600
S 400

s 6oo

8 600
2 200

A *
----- A ---

* Fall

150 200 250 300 350
N Rate (Iblacre)


Tomato Yields Total Harvest
Season 2005-06



200 250
N Rate (Iblacre)

Harvest Trial

* Fall
A Spring

300 350

XL L M Total

1 230 to 305 ns ns ns ns
2 305 vs. 370 ns ns ns ns
260 vs. 345
3 ns ns ns ns
4 200 vs. 260 ns ns ns ns

5 200 vs.300 GROWER ns GROWER ns
6 200 vs. 330 ns ns ns ns
7 200 vs. 320 ns GROWER GROWER GROWER
8 200 vs. 260 IFAS ns ns ns

z 25-lb tomatoes/box
Y XL = Extra-large (5x6 industry grade); L = Large (6x6); M = Medium (6x7)
x C = Yard waste compost 12 tons/acre
"growers, Ifas Significant and ns non-significant at P <0.01.

Fig. 2. Yield threshold curve for prices ranging from $4.50 to $18.50 per carton and for increasing N fertilizer from 200
to 300 Ib/acre N, assuming nitrogen costs of $.40 per Ib and harvesting/packing/selling costs of $3.50 per carton.


40 4 40.0


4.4 3.6
3.1 2.7

14.50 16.50 18.50
Price ($/ctn)


2 3,000
x 2,500
S 2,000





>- 15



4.50 6.50 8.50 10.50 12.50

Whitefly Resistance Update and
Proposed Mandated Burn Down Rule

David J. Schuster1, Raj Mann', and Phyllis R. Gilreath2
SUF/IFAS, Gulf Coast Research & Education Center,
Wimauma, ,I, 1,,, 1, i ,7,. 1, a
2 UF/IFAS, Manatee County Extension Service, Palmetto

A severe outbreak of Tomatoyellow leafcurlvirus (TYLCV)
in west-central Florida in the spring of 2006 emphasizes that
the vector of the virus, the silverleaf whitefly (SLWF), Bemisia
aigeiInitilii Bellows & Perring [also known as biotype B of the
sweetpotato whitefly, B. tabaci (Gennadius)], remains the key pest
oftomatoes in southernFlorida. The virus outbreak occurred despite
applications of the neonicotinoid Admire Pro (imidacloprid;
Bayer CropScience, Research Triangle Park, NC) to seedlings in
plant production houses and additional soil applications of either
Admire or Platinum (thiamethoxam; Syngenta Crop Protection,
Inc., Greensboro, NC), another neonicotinoid, and despite weekly
or more frequent foliar applications of additional insecticides
targeting whitefly adults. Other foliar applications of insecticides
targeted nymphs as the controlling effects of Admire or Platinum
Foliarly applied insecticides included Fulfill
(pymetrozene; Syngenta Crop Protection, Inc., Greensboro,
NC), Monitor (methamidophos; Valent U.S.A. Corporation,
Walnut Creek, CA), malathion (numerous suppliers), pyrethroids
(numerous products and suppliers), endosulfan (several suppliers),
Knack (pyriproxyfen; Valent U.S.A. Corporation, Walnut
Creek, CA), Courier (buprofezin; Nichino American, Inc.,
Wilmington, DE) soap and oil. Results were mixed and residual
control was short. Most growers refrained from making foliar
applications ofneonicotinoids including Provado (imidacloprid;
Bayer CropScience, Kansas City, MO) and Assail (acetamiprid;
Cerexagri, Inc., King of Prussia, PA) after nymphal control
with Admire or Platinum declined, because this practice could
encourage the development of resistance to the neonicotinoid
insecticides (Elbert and Nauen 2000).
There are several possible causes of the TYLCV outbreak
this past spring. The most important cause was the occurrence of
hurricane Wilma which destroyed or severely damaged tomato
plantings in southwestern and southeastern Florida. As a result,
fall production fields in west central Florida were held longer
than usual, with harvesting continuing into February and even
March. These fields overlapped with spring plantings and served
as reservoirs of migrating, viruliferous whitefly adults. Net house
studies have suggested that Admire is less effective in managing
whitefly adults, and the resulting transmission of TYLCV, than
in managing whitefly nymphs (Rubenstein et al. 1999). Efficient
and intensive whitefly adult management is, therefore, required
to reduce TYLCV incidence (Holt et al. 1999). Unfortunately,
growers and scouts have reported difficulty in controlling adults
with pyrethroids, pyrethroid/organophosphate combinations and
endosulfan. Declining susceptibility of whitefly adults to the
neonicotinoids, as was shown for Admire from 2001 to 2003

(Schuster et al. 2003), could also contribute to an increase in
TYLCV incidence; however, susceptibility of whitefly adults to
Admire had actually increased in 2004 (Schuster and Thompson
2004) and 2005 (Fig. 1). Thus, monitoring for potential
insecticide resistance and strict adherence to whitefly and resistant
management recommendations are needed to help reduce or
eliminate outbreaks.

A program to monitor the susceptibility of field populations
of the SLWF to Admire and Platinum using a cut leaf petiole
method was initiated in 2000 and continued in 2006 (Schuster
and Thompson 2001,2004; Schuster et al. 2002, 2003). Bioassays
were conducted using adults reared from foliage infested with
nymphs that had been collected from each tomato field. Standard
probit analyses (SAS Institute 1989) were used to estimate the
LCs0 values (the concentration estimated to kill 50% of the
population) for a laboratory colony and for each field population.
The laboratory colony used as a susceptible standard in this study
has been in continuous culture since the late 1980's without the
introduction of whiteflies collected from the field and, therefore,
would be expected to be particularly susceptible to insecticides.
The relative susceptibility (RS s) of each field population compared
to the laboratory colony was calculated by dividing the LCs0
values of the field populations by the LCs0 value of the laboratory
colony. Increasing values greater than one suggest decreasing
susceptibility in the field population. While values approaching
8 could indicate decreasing susceptibility of the whiteflies, such
variability is not unexpected when comparing field-collected
insects with susceptible, laboratory-reared insects. Values of 10
or greater, especially those of 20 or higher, are sufficiently high
to draw attention.
Average RSs0 values for Admire increased from 2000 to
2003, but decreased in both 2004 and 2005, although only two
populations were bioassayed in 2005 (Fig. 1). Average RSs0 values
for Platinum increased from 2003 to 2005. In 2006 average RSs0
values jumped tremendously for both Admire and Platinum. The
maximum RSs0 values observed were about 60 and 53 for Admire
and Platinum, respectively. These values are much higher than any
observed in previous years, especially for Platinum. The results
indicate a sudden reduction in susceptibility of whitefly adults
to both products; however, different persons have conducted the
bioassays over each of the last three years, which could contribute
to annual differences. New baseline RSs0 values for the lab colony
were obtained for each of the persons for each of the years, which
would help ameliorate any bias among the three persons. The
largest potential for bias among persons is involved in deciding
whether a whitefly adult is alive, dead, or moribund (dying);
however, the senior author reviewed the criteria with each person.
Therefore, susceptibility to Admire and Platinum appears to have
decreased in 2006, which should prompt growers to stringently
adhere to resistance management recommendations.
Biotype Q of the sweetpotato whitefly is the most prevalent
biotype in the Mediterranean region and has plagued greenhouse-
grown crops in southern Spain for years. This biotype is resistant
to many of the commonly used insecticides for managing


whiteflies, including the pyrethroids, neonicotinoids, pymetrozine
and insect growth regulators (Courier and Knack). Furthermore,
resistance in biotype Q is more stable than that in biotype B,
i.e. resistance does not diminish over time. Biotype Q has now
been found in greenhouses and nurseries in 22 states including
Florida. Although the biotype has not been detected in the field, it
represents a new threat to vegetables and other crops in Florida.
Strict adherence to management guidelines, especially those
dealing with crop hygiene and cultural controls, is important in
inhibiting or delaying the establishment of biotype Q in the field.
A Resistance Management Working Group was formed in
2003 to promote resistance management on a regional basis. The
group modified previous resistance management recommendations
(Schuster and Thompson 2001, 2004; Schuster et al. 2002, 2003)
and met with growers to encourage their adoption. The Working
Group consisted of University of Florida research and extension
personnel, representatives of the chemical companies marketing
neonicotinoid insecticides, representatives of commodity
organizations, and commercial scouts. Because of the threat of
biotype Q and decreased insecticide susceptibility, the group was
expanded and met in May, 2006 to once again to discuss and
revise the whitefly and resistance management recommendations.
The recommendations include field hygiene and cultural practices
which should be considered a high priority and should be included
as an integral part of the overall strategy for managing whitefly
populations, TYLCV incidence, and insecticide resistance. These
practices will help reduce the onset of the initial infestation of
whitefly and lower the initial infestation level during the cropping
period, thus reducing insecticide use and selection pressure for
insecticide resistance development. The recommendations also
include insecticide use recommendations which help improve
whitefly and resistance management.

Mandatory Burndown Rule
One outcome of whitefly, virus and resistance management
discussions has been the proposal of a mandatory "Tomato Plant
Destruction" rule by the Florida Department of Agriculture and
Consumer Services. The proposed wording of the rule at the time
of this publication states:

"Within five days following the final harvest of a
tomato crop, commercial tomato producers shall
destroy remaining tomato plants on the production
site using a chemical bum-down with a contact
desiccant type herbicide that is EPA labeled and
approved for this use such as paraquat that also
contains a minimum three percent oil and a non-
ionic adjuvant to destroy crop vegetation. This must
be followed by immediate complete destruction by
crop removal unless double cropping is planned."

Furthermore, the rule provides for enforcement:

"The commercial tomato producer failing to destroy
tomato plants within five days following final
harvest as described shall be issued an immediate
final order. An immediate final order issued by the
department pursuant to this section shall notify the
property owner that the tomato plants that are the
subject of the immediate final order must be removed
and destroyed unless the commercial tomato
producer, no later than 10 days after delivery of the
immediate final order requests and obtains a stay of
the immediate final order from the district court of
appeal with jurisdiction to review such requests. The
commercial tomato producer shall not be required
to seek a stay of the immediate final order by the
department prior to seeking the stay from the district
court of appeal. If the commercial tomato producer
refuses or neglects to comply with the terms of the
notice within 10 days after receiving it, the director
or her or his authorized representative may, under
authority of the department, proceed to destroy the
tomato plants. The expense of the destruction shall
be assessed, collected, and enforced against the
commercial tomato producer by the department."

This proposed rule is agreeable to most growers and is the
first attempt to manage the whitefly/virus situation in tomatoes
by regulatory enforcement. Some growers support defined,
mandatory crop free periods in the summer while others do not.
If progress is not made in the management the silverleaf whitefly
and associated TYLCV, pressure may build for a regulatory rule
stipulating crop destruct and crop planting dates.



A. Crop Hygiene.
Field hygiene should be a high priority and should be included
as an integral part of the overall strategy for managing whitefly
populations, TYLCV incidence, and insecticide resistance. These
practices will help reduce the onset of the initial infestation of
whiteflies, both biotype B and biotype Q (if present), and lower
the initial infestation level during the cropping period.

1. Establish a minimum two-month crop free period during the
summer, preferably from at least mid-June to mid-August.

2 Use a correct crop destruction technique, which includes
destruction of existing whitefly populations in addition to the
physical destruction of the crop.
a. Promptly and efficiently destroy all vegetable crops
within 5 days of final harvest to maximally decrease
whitefly numbers and sources of plant begomoviruses like
b. Use a contact desiccant ("bur down") herbicide in
conjunction with a heavy application of oil (not less than
3 % emulsion) and a non-ionic adjuvant to destroy crop
plants and to quickly kill whiteflies.
c. Time bur down sprays to avoid crop destruction during
windy periods, especially when prevailing winds are
blowing whiteflies toward adjacent plantings.
d. Destroy crops block by block as harvest is completed
rather than waiting and destroying the entire field at one

B. Other Cultural Control Practices.Reduce overall whitefly
populations, both biotvpe B and biotvpe 0 (if present), by
strictly adhering to cultural practices.

1. Use proper pre-planting practices.
a. Plant whitefly- and virus-free transplants.
1) Do not grow vegetable transplants and vegetatively
propagated ornamental plants (i.e. hibiscus, poinsettia,
etc.) at the same location, especially if bringing in
plant materials from other areas of the US or outside
the US.
2) Isolate vegetable transplants and ornamental plants if
both are produced at the same location.
3) Do not work with or manipulate vegetable transplants
and ornamental plants at the same time.
4) Practice worker isolationbetween vegetable transplants
and ornamental crops.
5) Avoid yellow clothing or utensils as these attract
whitefly adults.
6) Cover all vents and other openings with whitefly
resistant screening. Use double doors with positive
pressure. Cover roofs with UV absorbing films.

b. Delay planting new fall crops as long as possible.
c. Do not plant new crops near or adjacent to old, infested
d. Use determinant varieties of grape tomatoes to avoid
extended crop seasons.
e. Use TYLCV resistant tomato cultivars (see additional
information below for list) where possible and appropriate,
especially during historically critical periods of virus
pressure. Whitefly control must continue even with use
of TYLCV resistant cultivars because these cultivars can
carry the virus.
f Use TYLCV resistant pepper cultivars (see additional
information below for list) when growing pepper and
tomato in close proximity.
g. Use ultraviolet light reflective (aluminum) mulch on
plantings that are historically most susceptible to whitefly
infestation and TYLCV infection.

2. Use proper post-planting practices.
a. Apply an effective insecticide to kill whitefly adults prior
to cultural manipulations such as pruning, tying, etc.
b. Rogue tomato plants with symptoms of TYLCV at least
until second tie. Plants should be treated for whitefly
adults prior to roguing and, if nymphs are present, should
be removed from the field, preferably in plastic bags, and
disposed of as far from production fields as possible.
c. Manage weeds within crops to minimize interference with
spraying and to eliminate alternative whitefly and virus
host plants.
d. Dispose of cull tomatoes as far from production fields
as possible. If dumped in pastures for cattle feeding, the
fruit should be spread instead of dumped in a large pile to
encourage consumption by cattle. The fields should then
be monitored for germination of tomato seedlings and,
if present, they should be controlled by mowing or with
e. Avoid u-pick or pin-hooking operations unless effective
whitefly control measures are continued.
f. Destroy old crops within 5 days after harvest, destroy
whitefly infested abandoned crops, and control volunteer
plants with a desiccant herbicide and oil.

C. Insecticidal Control Practices.

1. Use a proper whitefly insecticide program. Follow the
a. On transplants in the production facility, do not use a
neonicotinoid insecticide ifbiotype Q is present. Ifbiotype
B is present, apply a neonicotinoid one time 7-10 days
before shipping. Use products in other chemical classes,
including Fulfill, soap, etc. before this time.
b. Use neonicotinoids in the field only during the first six
weeks of the crop, thus leaving a neonicotinoid-free
period at the end of the crop.
c. As control of whitefly nymphs diminishes following soil
drenches of the neonicotinoid insecticide or after more


than six weeks following transplanting, use rotations of
insecticides of other chemical classes including insecticides
effective against biotype Q. Consult the Cooperative
Extension Service for the latest recommendations.
d. Use selective rather than broad-spectrum control products
where possible to conserve natural enemies and enhance
biological control.
e. Do not apply insecticides on weeds on field perimeters
because this can kill natural enemies, thus interfering with
biological control, and because this can select for biotype
Q, if present, which is more resistant than biotype B to
many insecticides.

2. Soil applications of neonicotinoid insecticides for whitefly
a. For best control, use a neonicotinoid as a soil drench at
transplanting, preferably in the transplant water.
b. Soil applications of neonicotinoids through the drip
irrigation system are not recommended.
c. Do not use split applications of soil drenches of
neonicotinoid insecticides (i.e. do notapply at transplanting
and then again later).

3. Foliar applications of neonicotinoid insecticides for
whitefly control.
a. If foliar applications of a neonicotinoid insecticide are used
instead of or in addition to soil drenches at transplanting,
foliar applications should be restricted to the first six
weeks after transplanting. Do not exceed the maximum
active ingredient per season according to the label.
b. Follow scouting recommendations when using a foliar
neonicotinoid insecticide program. Rotate to non-
neonicotinoid insecticide classes after the first six weeks
and do not use any neonicotinoid class insecticides for the
remaining cropping period.

D. Do unto your neighbor as you would have him do unto

1. Look out for your neighbor's welfare.
This may be a strange or unwelcome concept in the highly
competitive vegetable industry but it is in your best interest
to do just that. Growers need to remember that should the
whiteflies develop full-blown resistance to insecticides,
especially the neonicotinoids, it's not just the other guy that
will be hurt-everybody will feel the pain! This is why the
Resistance Management Working Group has focused on
encouraging region-wide cooperation in this effort.

2. Know what is going on in the neighbor's fields.
Growers should try to keep abreast of operations in upwind
fields, especially harvesting and crop destruction, which both
disturb the foliage and cause whitefly adults to fly. Now that
peppers have been added to the list of TYLCV hosts, tomato
growers will need to keep in touch with events in that crop as

IRAC (Insecticide Resistance Action Committee) Website -
11ip m -online.org.

More suggestions for breaking the whitefly/TYLCV cycle
and a list of TYLCV resistant pepper cultivars can be found in
articles by Dr. Jane Polston in the 2002 and 2003 Proceedings
of the Florida Tomato Institute: http://swfrec.ifas.ufl.edu/veghort/
docs/tom inst 2002_091202.pdf and http://gcrec.ifas.ufl.edu/
TOMATO%202003.pdf, respectively. TYLCV resistant tomato
cultivars can be found in an article by Dr. Jay Scott in the 2004
Florida Tomato Institute Proceedings: http://gcrec.ifas.ufl.edu/

The authors wish to express their appreciation to Mary
Lamberts, Henry Yonce and Leon Lucas for identifying and/or
collecting whitefly samples for the 2006 monitoring, and to Bayer
CropScience for providing partial funding for the neonicotinoid
resistance monitoring. Appreciation also is expressed to
representatives of the Florida Tomato Committee, Florida Fruit
and Vegetable Association, Bayer CropScience, Syngenta Crop
Protection, Cerexagri Inc., Glades Crop Care, Agricultural Crop
Consulting,Agri-Tech Services, and Integrated Crop Management,
and to UF/IFAS personnel Alicia Whidden, Gene McAvoy, Jim
Price and Phil Stansly for their participation in the Resistance
Management Working Group and for their many contributions to
the whitefly and resistance management recommendations.

Elbert, A. and R. Nauen. 2000. Resistance in Bemisia tabaci
(Homoptera: Aleyrodidae) to insecticides in southern Spain with
special reference to neonicotinoids. Pest Management Sci. 56:60-

Holt, J., J. Colvin and V Muniyappa. 1999. Identifying
control strategies for tomato leaf curl virus disease using and
epidemiological model. J. Appl. Ecol. 36:625-633.

Rubenstein, G., S. Morin and H. Czosnek. 1999. Transmission of
tomato yellow leaf curl geminivirus to imidacloprid treated tomato
plants by the whitefly Bemisia tabaci (Homoptera: Aleyrodidae).
J. Econ. Entomol. 92:658-662.

SAS Instititute Inc. 1989. SAS/STAT User's Guide, Version 6,
Fourth Edition, Bol. E, SAS Institute Inc., Cary, NC.

Schuster, D. J. And S. Thompson. 2001. Monitoring susceptibility
of the silverleaf whitefly to imidacloprid, pp. 16-18. In P Gilreath
and C. S. Vavrina [eds.], 2001 Fla. Tomato Institute Proc., Univ.
Fla., Gainesville, PRO 518.


Schuster, D. J. And S. Thompson. 2004. Silverleaf whitefly
resistance management update, pp. 19-25. In P Gilreath and W.
H. Stall [eds.], Fla. Tomato Institute Proc., Univ. Fla., Gainesville,
PRO 521.

Schuster, D. J., S. Thompson, P A. Stansly and J. Conner. 2002.
Update on insecticides for whitefly and leafminer control, pp.
51-60. In P Gilreath and C. S. Vavrina [eds.], 2002 Fla. Tomato
Institute Proc., Univ. Fla., PRO 519.

Schuster, D. J., S. Thompson and P R. Gilreath. 2003. What's up
with all these whiteflies?, pp. 12-19. In P Gilreath and W H. Stall
[eds.], Fla. Tomato Institute Proc., Univ. Fla., PRO 520.

10 0


2000 2001 2002 2003 2004 2005 2006

0 -







Fig. 1. Monitoring relative susceptibility (RSo,) of whitefly adults from
nicotinoid-treated tomato fields to Admire (A) or Platinum (B) using a
laboratory bioassay. Numbers at the top of the bars are the average
RS,, values and the numbers inside the bar are the number of
populations bioassayed and the number with RS,, values >10 (in







TYLCV-resistant Tomato Cultivar
Trial and Whitefly Control

Kent Cushman and Phil Stansly
UF/IFAS, Southwest Florida Research & Education
Center, Immokalee

kcushman@ufl.edu; pstansly@ulf edu

Commercial tomato growers in much of the rest of the
country try to limit losses due to a disease vectored by thrips called
Tomato Spotted Wilt Virus. Not so in south and central Florida.
Here growers strive to limit losses due to Tomato Yellow Leaf Curl
Virus (TYLCV), a disease vectored by whitefly and a problem we
share in common with other tropical and semi-tropical regions of
the world. This report presents results of two trials conducted in
southwest Florida during Spring 2006 to evaluate management of
TYLCV in commercial tomato plantings using resistant cultivars
and whitefly control strategies.

Variety Trial. One way to control losses due to TYLCV is
for the plant to do most of the work. Tomato cultivars resistant to
TYLCV have been available for many years, but for one reason
or another they have not been well received by Florida growers.
Cultivars used on commercial farms must produce plants that
are strong, disease resistant, and highly productive and that yield
large, round fruit with good holding and shipping ability. Excellent
choices are available, but often these cultivars were developed for
other markets, such as markets that prefer smaller-sized fruit or a
more flattened shape, or were developed in less humid areas.
Twelve entries of TYLCV-resistant cultivars and numbered
breeders' selections and one entry of a standard TYLCV-
susceptible cultivar (Table 1) were evaluated in a replicated
trial at the Southwest Florida Research and Education Center
(SWFREC). Seed were planted in flats and grown on site. Plants
were transplanted to the field on Feb. 20. Seed of Zeraim Gedera
arrived late and were planted in flats and then transplanted to
the field on Feb. 24. The crop was grown on raised beds with
black plastic mulch and was irrigated and fertilized with drip
tubing. A standard insect and disease control program was used
throughout the duration of the crop, including an imidacloprid
drench at transplant and whitefly control thereafter. The goal of
the trial was to evaluate horticultural characteristics of each entry
and not the level of virus resistance. Tomatoes were harvested
three times, May 10, 24, and June 6. At each harvest, marketable
fruit were separated by mature green and later maturities and then
graded by size, counted, and weighed. Unmarketable fruit were
separated by cull categories and also counted and weighed. The
experimental design was a randomized complete block and data
were statistically analyzed to determine significant differences.
Growing conditions were excellent with little rainfall and
relatively warm, sunny days. Whitefly populations were low
until the second harvest at which time populations became well
established in the planting. At the time of final harvest, TYLVC-
resistant cultivars had no virus-affected plants and susceptible
cultivars had a low level of incidence (Table 1). The two entries

from Abbott & Cobb had higher levels of TYLVC disease than
the standard cultivar Florida 47. A previous trial at this location
experienced a high level of disease in susceptible cultivars
(Gilreath et al. 2000).
HA 3075 (Hazera) produced the highest total yield, though
its total yield was similar to that ofACR-2012 (Abbott and Cobb),
S-50257, VT-60774, and VT-60780 (Zeraim Gedera). HA 3075
was the only entry to produce significantly greater total yield than
'Florida 47' (Table 2). HA 3075 also produced the highest yield
of 5x6s, though yield of this size category was similar to that of
Florida 47 (Table 3). Despite having the highest yield, HA 3075
did not produce the largest fruit in this size category. BHN 745
(BHN Seed) averaged 5x6 fruit of 9.4 ounces and this was similar
to that of 'Florida 47' and 'Tygress' at 9.1 ounces each. HA 3075
averaged 8.3 ounces per fruit in the 5x6 size category. S-50260
produced the highest percentage of cull fruit, though its percentage
of cull fruit was similar to that of HA 3074, Fla 8477, and BHN
745. Defects of fruit of S-50260 and Fla 8477 were mostly due
to zipper scarring and catfacing. Fruit of S-50252 also exhibited
a high percentage of zipper scarring and catfacing compared to
most other entries.
In conclusion, several entries produced total yields equal
to or better than the standard cultivar. Based on marketable yield,
cull categories, and size and shape of marketable fruit, TYLCV-
resistant entries from this trial that could be grown for observation
in small blocks on commercial farms are HA 3075, S-50257, VT-
60774, and VT-60780, and BHN 745.

Cultivars in Combination with Control Strategies. A
trial was conducted at SWFREC to evaluate the interaction of
cultivar and control strategies. One TYLCV-resistant cultivar,
Tygress, and one TYLCV-susceptible cultivar, Florida 47, were
planted 22 Feb. 2006 in raised beds with black plastic mulch and
drip irritation. Whitefly control strategies were applied to cultivars
in an unbalanced experimental design, with more treatments
applied to 'Florida 47' than 'Tygress'. All treatments (Table 4)
were replicated four times.
Average numbers of whitefly adults during the first six
weeks of the trial were low, but numbers increased dramatically
during the later five weeks. Most adult whiteflies were observed
on untreated 'Tygress' plants, although not significantly more
than on the untreated 'Florida 47'. Numbers of adults seen on
plants treated with the low (8 oz) rate of Platinum followed by
the standard spray combination were not different from either
untreated check (Fig. 1). Fewest whiteflies were observed on
plants treated with Admire at planting, then the low rate of NNI
0101, though not less than plants treated the same except with
the higher rate of NNI 0101, in turn not significantly different
from plants sprayed with the standard or with oil following
the Admire drench. Fewest whitefly eggs were seen on plants
sprayed following the Admire drench with the high rate of NNI
0101 twice and Courier once or weekly with JMS Stylet oil, with
no differences compared to the untreated controls exhibited by
the other treatments (Fig. 2). The checks were not significantly
different in regard to small nymphs than the remaining treatments
with significantly fewer of these seen in all remaining treatments.
Fewest small nymphs were seen on plants treated with the high rate


ofNNI 0101, though not significantly so compared to treatments
with either rate of Platinum instead of Admire, or by substituting
these sprays with the standard spray schedule or JMS Oil. More
large nymphs were seen on unsprayed 'Florida 47' than unsprayed
'Tygress', with no differences between this latter control and all
remaining treatments except the high (11 oz) rate of Platinum.
Few plants were observed with symptoms of TYLCV throughout
the course of the trial, and they aggregated in unusual ways with
most seen on plants treated with 11 oz of Platinum followed by
the standard spray schedule. However, no virus symptoms were
seen on the 'Tygress' plants except for one possible case in an
unsprayed plot, although this was not significantly different than
the other treatments except for 'Florida 47' treated according to the
standard schedule or the aforementioned Platinum and standard
sprays. All treated plants yielded more marketable fruit than
untreated plants, with most harvested from 'Tygress' receiving the
standard treatment, though not significantly different from all but
oil, Platinum and check plants. Similarly, fewest culls were taken
from plants receiving the standard treatment regardless of variety,
though not significantly less than plants receiving either rate of
Platinum, NNI 0101 or oil.
In conclusion, resistant varieties showed little or no virus
symptoms, resulting in a trend toward better yield although the
difference was not significant, probably because of low virus
incidence. However, unsprayed resistant or susceptible plants
yielded the same. Nichino 0101, a growth inhibitor, provided
control of whiteflies comparable to the standard treatment of
adults. Weekly oil treatment after theAdmire drench also provided
good whitefly control although the yield suffered somewhat,
comparable to plants treated with Platinum at the low rate followed
by the standard sprays. Although this trial did not demonstrate a
clear advantage to using the resistant variety under conditions of
low virus pressure, neither was there any disadvantage. Thus, use
of 'Tygress' in the spring growing season could provide an extra
measure of security to the grower, over and above the standard
insecticidal regime.

Table 1. Cultivars and advanced breeder'svarieties evaluated
in this study along with seed source, fruit shape,
and percentage of diseased plants observed in the
variety trial.

Variety Source Diseased plants
Variety Source

Florida 47 Seminis 5
Tygress Seminis 0
Fla 8477 UF/IFAS 0
BHN 745 BHN 0
HA 3074 Hazera 0
HA 3075 Hazera 0
ACR-242 Abbott & Cobb 8
ACR-2012 Abbott & Cobb 7
S-50252 Zeraim Gedera 0
S-50257 Zeraim Gedera 0
S-50260 Zeraim Gedera 0
VT-60774 Zeraim Gedera 0
VT-60780 Zeraim Gedera 0
SPercentage of TYLVC-affected plants at end of trial, after third
harvest. Values are means of four replications of 10-12 plants.

Gilreath, P., P Stansly, K. Shuler, J. Polston, T. Sherwood, G.
McAvoy, and E. Waldo. 2000. Tomato yellow leaf curl virus
resistant tomato variety trials. Proc. Fla. State Hort. Soc. 113:190-


Table 2. Marketable yield by size category, percent of total yield at breaker stage or beyond, and average weight of 5x6 (extra-
large), 6x6 (large), and 6x7 (medium) sized fruit.

Marketable yield (boxes/acre)' % Avg fruit wt (oz)

Treatments 5x6 6x6 6x7 Total Color 5x6 6x6 6x7

Florida 47
Fla 8477
BHN 745
HA 3074
HA 3075

2,380 ab
2,310 b
1,760 de
2,240 bc
2,120 b-d
2,780 a
2,040 b-d
2,200 bc
1,880 cd
1,420 ef
2,360 b
1,880 cd

158 h-j
369 d-f
133 ij
265 f-h
238 g-i
396 de
396 de
519 bc
757 a
465 cd
332 e-g
585 b

226 e-g
131 g
379 cd
267 d-g
248 d-g
331 de
368 cd
489 bc
761 a
481 bc
317 d-f
591 b

2,760 b-e
2,550 d-f
2,500 ef
2,560 d-f
2,650 c-e
3,270 a
2,760 b-e
2,960 a-c
2,880 b-d
2,940 a-c
2,240 f
3,010 a-c
3,050 ab

30 ef
29 ef
37 de
53 bc
37 de
54 a-c
44 cd
63 a
64 a
61 ab
39 de
61 ab

9.1 a
9.1 a
7.6 de
9.4 a
8.2 bc
8.3 b
7.5 de
7.9 cd
7.4 ef
6.9 g
7.1 fg
7.9 cd
7.6 de

5.6 a-c
5.5 a-d
5.6 ab
5.5 b-d
5.6 a-c
5.7 a
5.5 a-d
5.7 a
5.6 a-d
5.5 dc
5.4 d
5.5 b-d
5.5 a-d

4.7 ab
4.6 a-d
4.7 a
4.4 d
4.8 a
4.6 a-c
4.5 b-d
4.8 a
4.7 ab
4.4 cd
4.6 a-d
4.6 a-d
4.6 a-d

zMarketable yield is mature green fruit plus later maturities but minus unmarketable (cull) fruit. Values are means of four replications of
10 or 12 plants. Means followed by the same letter are not statistically different at P:0.05.

Table 3. Unmarketable (cull) categories and total unmarketable weight. Blossom end scar (BES), zipper and catface, sunscald
and yellow shoulder (SS, YS), radial and concentric cracking (Crk), misshapen (Mspn), and other cull categories.

Unmarketable fruit by cull category (%)z

Zip +Catface
4.5 f-h
7.1 de
10.4 b
7.9 cd
6.4 d-f
1.4 i
2.7 hi
5.3 e-g
9.9 bc
5.1 e-g
13.7 a
3.2 g-i
1.5 i


1.2 c-e
1.1 c-e
0.4 e
2.1 bc
4.7 a
2.2 bc
0.7 de
1.8 b-d
0.6 de
0.5 e
0.4 e
2.9 b
0.4 e

0.8 cd
1.2 bc
1.0 b-d
0.8 cd
1.4 bc
1.3 bc
2.3 a
0.3 d
1.2 bc
0.7 cd
0.7 cd
0.9 b-d

1.3 de
2.5 bc
3.8 a
2.6 a-c
3.0 ab
1.9 b-e
2.1 b-d
2.0 b-e
1.7 c-e
0.9 e
2.5 bc
2.4 b-d
1.7 c-e


Florida 47
Fla 8477
BHN 745
HA 3074
HA 3075

0.3 de
0.3 de
1.3 c
2.8 b
2.5 b
1.1 cd
0.6 c-e
3.7 a
0.7 c-e
0.1 e
0.3 de
0.4 de
0.7 c-e

9.6 e-g
12.2 de
17.8 ab
16.9 a-c
18.2 ab
9.0 f-h
7.7 gh
15.6 bc
14.6 cd
8.9 f-h
19.3 a
11.0 ef
6.5 h

Total Cull wt

326 bc
372 bc
726 a
362 bc
241 c
711 a
592 a
322 bc
419 b
229 c

SUnmarketable (cull) categories reported as percentage of total number of marketable plus unmarketable fruit. Values are means of four
replications of 10 or 12 plants. Means followed by the same letter are not statistically different at P:0.05.

Table 4.


Treatment Cultivar Product Rate 1 2 3 4 5 6 7 8 9 10 11 12 13 14

S Chk
R Stdrd

Florida 47

Admire Pro 4.6L
Oberon 2SC
Admire Pro 4.6L
Oberon 2SC
Platinum 2SC
Oberon 2SC
Platinum 2SC
Oberon 2SC
Admire Pro 4.6L
JMS Stylet Oil
Admire Pro 4.6L
Courier 40SC
Admire Pro 4.6L
Courier 40SC






Nich H

7 fl oz per acre
8 fl oz per acre
9 fl oz per acre
7 fl oz per acre
8 fl oz per acre
9 fl oz per acre
8 fl oz per acre
8 fl oz per acre
9 fl oz per acre
11 fl oz per acre
8 fl oz per acre
9 fl oz per acre
7 fl oz per acre
1 % v/v
7 fl oz per acre
12 fl oz per acre
0.2 Ib per acre a.i.
7 fl oz per acre
12 fl oz per acre
0.3 Ib per acre a.i.

Florida 47

Florida 47

Florida 47

Florida 47

Florida 47

Florida 47

x x x

Figure 1. Average number adult whiteflies collected in 4 beats over 11 sample weekly dates.



15 -




Co 9~~4



Figure 2. Average number of eggs, small nymphs and large nymphs over 10 weekly sample dates.

m Eggs
_6 0 Small Nymphs
5 -- La4rgeNymphs

4T I-T

T 1


hIlL Ihik lii



. I L 1; ik

Figure 3. Mean incidence of plants with TYLCV symptoms in tomato plots.





20 -

15 -



0 I

Columns designated by the same letter represent means that are not significantly different (LSD, P < 0.05)

Figure 4. Mean weight from 8 plants of marketable and unmarketable fruit yield from 6 harvests.

Columns designated by the same letter represent means that are not significantly different (LSD, P < 0.05).
Columns representing marketable yield were analyzed separate from columns representing unmarketable yield.


Tomato Varieties for Florida

Stephen M. Olson' and Eugene McAvoy2
SNorth Florida Research & Education Center University
of Florida, Quincy; gmcavoy@ufl.edu
2 Hendry County Extension, University of Florida,
Labelle; smolson @ufl.edu

Variety selections, often made several months before
planting, are one of the most important management decisions
made by the grower. Failure to select the most suitable variety
or varieties may lead to loss of yield or market acceptability. The
following characteristics should be considered in selection of
tomato varieties for use in Florida.

Yield The variety selected should have the potential to
produce crops at least equivalent to varieties already grown. The
average yield in Florida is currently about 1400 25-pound cartons
per acre. The potential yield of varieties in use should be much
higher than average.

Disease Resistance Varieties selected for use in Florida
must have resistance to Fusarium wilt, races 1 and 2 and in
some areas race 3; Verticillium wilt (race 1); Gray leaf spot; and
some tolerance to Bacterial soft rot. Available resistance to other
diseases may be important in certain situations, such as Tomato
spotted wilt and Bacterial wilt resistance in northwest Florida.

Horticultural Quality Plant habit, stem type and fruit size,
shape, color, smoothness and resistance to defects should all be
considered in variety selection.

Adaptability Successful tomato varieties must perform well
under the range of environmental conditions usually encountered
in the district or on the individual farm.

Market Acceptability The tomato produced must have
characteristics acceptable to the packer, shipper, wholesaler,
retailer and consumer. Included among these qualities are pack
out, fruit shape, ripening ability, firmness, and flavor.

Many tomato varieties are grown commercially in Florida,
but only a few represent most of the acreage. In years past we have
been able to give a breakdown of which varieties are used and
predominantly where they were being used but this information is
no longer available through the USDA Crop Reporting Service.

Table 1 shows results of spring trials for 2005 and Table 2
shows results of fall trial of 2005 conducted at the North Florida
Research and Education Center, Quincy.

The following varieties are currently popular with Florida
growers or have done well in university trials. It is by no means a
comprehensive list of all varieties that may be adapted to Florida
conditions. Growers should try new varieties on a limited basis to
see how they perform for them.

Amelia. Vigorous determinate, main season,jointed hybrid.
Fruit are firm and aromatic suitable for green or vine ripe. Good
crack resistance. Resistant: Verticillium wilt (race 1), Fusarium
wilt (race 1,2,3), root-knot nematode Gray leaf spot and Tomato
spotted wilt. (Harris Moran).

BHN 586. Midseason maturity. Fruit are large to extra-large,
deep globed shaped with firm, uniform green fruits well suited for
mature green or vine-ripe production. Determinate, medium to tall
vine. Resistant: Verticillium wilt (race 1), Fusarium wilt (race 1,2)
Fusarium crown rot and root-knot nematode. (BHN)

BHN 640. Early-midseason maturity. Fruit are globe shape
but tend to slightly elongate, and green shouldered. Not for fall
planting. Resistant: Verticillium wilt (race 1), Fusarium wilt (race
1,2,3), Gray leaf spot, and Tomato spotted wilt. (BHN).

Crista. Midseason maturity. Large, deep globe fruit with
tall robust plants. Does best with moderate pruning and high
fertility. Good flavor, color and shelf-life. Resistant: Verticillium
wilt (race 1), Fusarium wilt (race 1,2,3), Tomato spotted wilt and
root-knot nematode. (Harris Moran)

Crown Jewel. Uniform fruit have a deep oblate shape
with good firmness, quality and uniformly-colored shoulders.
Determinate with medium-tall bush. Resistant: Verticillium wilt
(race 1), Fusarium wilt (race 1,2) Fusarium crown rot, Altemaria
stem canker and Gray leaf spot. (Seminis)

Florida 47. A late midseason, determinate, jointed hybrid.
Uniform green, globe-shaped fruit. Resistant: Fusarium wilt (race
1,2), Verticillium wilt (race 1), Alternaria stem canker, and Gray
leaf spot. (Seminis).

Florida 91. Uniform green fruit borne on jointed
pedicels. Determinate plant. Good fruit setting ability under high
temperatures. Resistant: Verticillium wilt (race 1), Fusarium wilt
(race 1,2), Alternaria stem canker, and Gray leaf spot. (Seminis).

HA 3073. A midseason, determinate, jointed hybrid. Fruit
are large, firm, slightly oblate and are uniformly green. Resistant:
Verticillium wilt (race 1), Fusarium wilt (race 1,2), Gray leaf spot,
Tomato yellow leaf Curl and Tomato mosaic. (Hazera)

Linda. Main season. Large round, smooth, uniform
shouldered fruit with excellent firmness and a small blossom
end scar. Strong determinate bush with good cover. Resistant:


Verticillium wilt (race 1), Fusarium wilt (race 1,2), Alternaria
stem canker and Gray leaf spot. (Sakata)

Phoenix. Early mid-season. Fruit are large to extra-large,
high quality, firm, globe-shaped and are uniformly-colored. "Hot-
set" variety. Determinate, vigorous vine with good leaf cover for
fruit protection. Resistant: Verticillium wilt (race 1), Fusarium wilt
(race 1,2), Altemaria stem canker and Gray leaf spot. (Seminis)

Quincy. Full season. Fruit are large to extra-large, excellent
quality, firm, deep oblate shape and uniformly colored. Very strong
determinate plant. Resistant: Verticillium wilt (race 1), Fusarium
wilt (race 1,2), Alternaria stem canker, Tomato spotted wilt and
Gray leaf spot. (Seminis)

RPT 6153. Main season. Fruit have good eating quality
and fancy appearance in a large sturdy shipping tomato and are
firm enough for vine-ripe. Large determinate plants. Resistant:
Verticillium wilt (race 1), Fusarium wilt (race 1,2) and Gray leaf
spot. (Seedway)

Sanibel. Main season. Large, firm, smooth fruit with light
green shoulder and a tight blossom end. Large determinate bush.
Resistant: Verticillium wilt (race 1), Fusarium wilt (race 1,2),
root-knot nematodes, Alternaria stem canker and Gray leaf spot.

Sebring. A late midseason determinate, jointed hybrid
with a smooth, deep oblate, firm, thick walled fruit. Resistant:
Verticillium wilt (race 1), Fusarium wilt (race 1,2,3), Fusarium
crown rot and Gray leaf spot. (Syngenta)

Solar Fire. An early, determinate, jointed hybrid. Has good
fruit setting ability under high temperatures. Fruit are large, flat-
round, smooth, firm, light green shoulder and blossom scars are
smooth. Resistant: Verticillium wilt (race 1), Fusarium wilt (race
1,2,3) and Gray leaf spot. (Harris Moran)

Solar Set. An early, green-shouldered, jointed hybrid.
Determinate. Fruit set under high temperatures (92oF day/72o
night) is superior to most other commercial varieties. Resistant:
Fusarium wilt (race 1,2), Verticillium wilt (race 1), Alternaria
stem canker, and Gray leaf spot. (Seminis).

Solimar. A midseason hybrid producing globe-shaped,
green shouldered fruit. Resistant: Verticillium wilt (race 1),
Fusarium wilt (race 1,2), Alternaria stem canker, Gray leaf spot.

Soraya. Full season. Fruit are high quality, smooth and tend
toward large to extra-large. Continuous set. Strong, large bush.
Resistant: Verticillium wilt (race 1), Fusarium wilt (race 1,2,3),
Fusarium crown rot and Gray leaf spot. (Syngenta Rogers Seed)

Talledega. Midseason. Fruit are large to extra-large,
globe to deep globe shape. Determinate bush. Has some hot-set
ability. Performs well with light to moderate pruning. Resistant:

Verticillium wilt (race 1), Fusarium wilt (race 1,2), Tomato spotted
wilt and Gray leaf spot. (Syngenta Rogers Seed)

Tygress. A midseason, jointed hybrid producing large,
smooth firm fruit with good packouts. Resistant: Verticillium wilt
(race 1), Fusarium wilt (race 1,2), Gray leaf spot, Tomato mosaic
and Tomato yellow leaf curl. (Seminis).

Bella Rosa. Heat tolerant determinate type. Produces firm,
uniformly shaped fruit. Resistant: Tomato spotted wilt. (Sakata)

BHN 410. Midseason. Large, smooth, blocky, jointless
fruit tolerant to weather cracking. Compact to small bush with
concentrated high yield. Resistant: Verticillium wilt (race 1),
Fusarium wilt (race 1, 2), Bacterial speck (race 0) and Gray leaf
spot. (BHN Seed)

BHN 411. Midseason. Large, smooth, jointless fruit is
tolerant to weather cracks and has reduced tendency for graywall.
Compact plant with concentrated fruit set. Resistant: Verticillium
wilt (race 1), Fusarium wilt (race 1,2), Bacterial speck (race 0) and
Gray leaf spot. (BHN Seed)

BHN 485. Midseason. Large to extra-large, deep blocky,
globe shaped fruit. Determinate, vigorous bush with no pruning
recommended. Resistant: Verticillium wilt (race 1), Fusarium wilt
(race 1,2,3) and Tomato spotted wilt. (BHN Seed)

Marianna. Midseason. Fruit are predominately extra-large
and extremely uniform in shape. Fruit wall is thick and external
and internal color is very good with excellent firmness and shelf
life. Determinate, small to medium sized plant with good fruit
set. Resistant: Verticillium wilt (race 1), Fusarium wilt (race 1,2),
root-knot nematode, Alternaria stem canker and tolerant to Gray
leaf spot. (Sakata)

Monica. Midseason. Fruit are elongated, firm, extra-
large and uniform green color. Vigorous bush with good cover.
Resistant: Verticillium wilt (race 1), Fusarium wilt (race 1,2),
Bacterial speck (race 0) and Gray leaf spot. (Sakata)

Plum Dandy. Medium to large determinate plants.
Rectangular, blocky, defect-free fruit for fresh-market production.
When grown in hot, wet conditions, it does not set fruit well and is
susceptible to bacterial spot. For winter and spring production in
Florida. Resistant: Verticillium wilt, Fusarium wilt (race 1), Early
blight, and rain checking. (Harris Moran).

Sunoma. Main season. Fruit are medium-large, elongated
and cylindrical. Plant maintains fruit size through multiple
harvests. Determinate plant with good fruit cover. Resistant:
Verticillium wilt (race 1), Fusarium wilt (race 1,2), Bacterial
speck (race 0), root-knot nematodes, Tomato mosaic and Gray
leaf spot. (Seminis)


BHN 268. Early. An extra firm cherry tomato that holds,
packs and ships well. Determinate, small to medium bush with
high yields. Resistant: Verticillium wilt (race 1), Fusarium wilt
(race 1). (BHN Seed)

Camelia. Midseason. Deep globe, cocktail-cherry size
with excellent firmness and long shelf life. Indeterminate bush.
Outdoor or greenhouse production. Verticillium wilt (race 1),
Fusarium wilt (race 1) and Tobacco mosaic. (Siegers Seed)

Cherry Blossom. 70 days. Large cherry, holds and yields
well. Determinate bush. Resistant: Verticillium wilt (race 1),
Fusarium wilt (race 1,2), Bacterial speck (race 0), root-knot
nematodes, Alternaria stem canker and Gray leaf spot. (Seedway)

Mountain Belle. Vigorous, determinate type plants. Fruit
are round to slightly ovate with uniform green shoulders borne on
jointless pedicels. Resistant: Fusarium wilt (race 2), Verticillium
wilt (race 1). (Syngenta Rogers Seed).

Super Sweet 100 VE Produces large clusters of round
uniform fruit with high sugar levels. Fruit somewhat small and
may crack during rainy weather. Indeterminate vine with high
yield potential. Resistant: Verticillium wilt (race 1) and Fusarium
wilt (race 1). (Siegers Seed, Seedway)

Shiren. Compact plant with high yield potential and nice
cluster. Resistant: Fusarium wilt (race 1,2), root-knot nematodes
and Tomato mosaic. (Hazera)

Brixmore. Very early. Indeterminate. Very uniform in
shape and size, deep glossy red color with very high early and total
yield. High brix and excellent firm flavor. Resistant: Verticillium
wilt (race 1), root-knot nematodes and Tomato mosaic. (Harris

Cupid. Early. Vigorous, indeterminate bush. Oval-shaped
fruit have an excellent red color and a sweet flavor. Resistant:
Fusarium wilt (race 1,2), Bacterial speck (intermediate resistance
race 0) and Gray leaf spot. (Seminis)

Jolly Elf. Early season. Determinate plant. Extended
market life with firm, flavorful grape-shaped fruits. Average 10%
brix. Resistant: Verticillium wilt (race 1), Fusarium wilt (race 2)
and cracking. (Siegers Seed, Seedway)

Santa. 75 days. Vigorous indeterminate bush. Firm
elongated grape-shaped fruit with outstanding flavor and up to 50
fruits per truss. Resistant: Verticillium wilt (race 1), Fusarium wilt
(race 1), root-knot nematodes and Tobacco mosaic. (Thompson
and Morgan)

St Nick. Mid-early season. Indeterminate bush. Oblong,
grape-shaped fruit with brilliant red color and good flavor. Up to
10% brix. (Siegers Seed)

Smarty. 69 days. Vigorous, indeterminate bush with short
internodes. Plants are 25% shorter than Santa. Good flavor, sweet
and excellent flavor. (Seedway)


Table 1. Tomato variety trial results spring 2005. NFREC-Quincy, FL.

Marketable Yield (25 Ib cartons/A Fruit wt. Marketable TSW










Quincy (8383) Seminis 200 e-iz 359 b-g 1858 a 2416 a 7.3 ab 85.9 a-e 0
NC 0227 NCS 354 b-d 536 a 1493 a-d 2384 a 6.5 b-g 86.0 a-e 0
SXT 6741 Nunhems 286 b-h 455 a-d 1596 ab 2337 ab 6.6 b-g 88.9 a 0
NC 0236 NCS 335 b-e 450 a-d 1528 a-c 2314 ab 6.7 b-g 86.8 a-d 8.3
Crista (NC 0256) Harris Moran 260 c-h 390 a-g 1611 ab 2260 a-c 6.7 b-g 86.6 a-d 0
NC 0377 NCS 405 b 516 ab 1338 a-e 2259 a-c 6.3 c-g 84.0 a-f 0
NC 0392 NCS 302 b-h 467 a-d 1462 a-d 2231 a-c 6.8 b-f 88.4 ab 0
BHN 444 BHN 356 b-d 524 ab 1314 a-e 2194 a-d 6.4 c-g 81.4 a-f 2.1
Talladega Syngenta 171 g-i 346 c-g 1608 ab 2125 a-e 7.0 b-d 81.9 a-f 2.1
SXT 6758 Nunhems 255 c-h 428 a-f 1314 a-e 1996 a-e 6.2 d-g 87.4 a-c 0
BHN 640 BHN 356 b-d 500 a-c 1106 b-f 1962 a-e 6.1 e-g 80.4 a-f 0
BHN 601 BHN 392 bc 481 a-d 1039 b-f 1913 a-e 6.0 fg 83.6 a-f 0
Amelia Harris Moran 186 f-i 329 d-g 1396 a-e 1911 a-e 7.0 b-d 84.6 a-e 2.1
Phoenix (8233) Seminis 194 e-i 340 c-g 1372 a-e 1906 a-e 7.1 a-c 77.7 d-g 2.1
*FL 47 Seminis 180 g-i 363 b-g 1324 a-e 1868 a-e 6.9 b-e 82.1 a-f 20.8
Top Gun (503) Seminis 217 d-i 383 a-g 1251 a-e 1851 a-e 6.6 b-g 82.7 a-f 0
Fla. 7964 GCREC 312 b-g 445 a-e 1020 b-f 1778 a-e 6.2 d-g 77.3 e-g 0
Solar Fire Harris Moran 273 b-h 406 a-g 1091 b-f 1771 a-e 6.3 c-g 83.1 a-f 27.1
Fla. 8314 GCREC 292 b-h 403 a-g 1051 b-f 1746 a-e 6.2 d-g 78.3 c-f 14.6
Soraya Syngenta 166 hi 276 fg 1276 a-e 1719 a-f 7.1 a-c 81.0 a-f 16.7
Fla. 8224 GCREC 326 b-f 394 a-g 933 c-f 1653 b-f 6.0 g 80.3 a-f 27.1
Mountain Spring Syngenta 240 d-h 280 e-g 1124 b-f 1644 b-f 6.7 b-g 79.9 a-f 22.9
Fla. 8153 GCREC 592 a 496 a-d 492 f 1579 c-f 5.2 h 79.9 b-f 22.9
FL 91 Seminis 175 g-i 274 fg 1056 b-f 1504 d-f 6.7 b-g 83.0 a-f 16.7
Sebring Syngenta 169 g-i 251 gh 1068 b-f 1487 ef 6.8 b-e 84.2 a-e 16.7
Fla. 8135 GCREC 275 b-h 365 b-g 787 ef 1428 ef 6.1 e-g 75.0 fg 22.9
Biltmore Seminis 81 i 125 h 851 d-f 1056 f 7.8 a 69.9 g 37.5

z Mean separation by Duncan's multiple range test, 5 % level.
Comments: In-row spacing 20 in., between row spacing 6 ft., trickle irrigation under black polyethylene mulch, fertilizer applied 195-60-
195 Ibs/A N-P205-K20. Seeded: 14 February 2005. Transplanted 29 March 2005. Harvested 23 June 7 July, 3 harvests; Soil: Orangeburg
loamy fine sand


Table 2. Tomato variety trial results fall 2005. NFREC-Quincy, FL.

Marketable Yield (25 Ib cartons/A Fruit wt. Marketable

Entry Source Medium Large Extra-large Total (oz) (%)



238 a-cz


1072 ab

1729 a

5.7 c-e

86.4 ab

Phoenix (8233) Seminis 96 e-g 232 c-f 1201 a 1528 ab 6.6 a 87.6 ab
Solar Fire; Harris Moran 250 ab 414 ab 828 a-e 1492 a-c 5.5 c-g 83.9 a-c
Quincy (8383) Seminis 84 fg 172 d-f 1142 a 1398 a-d 6.7 a 88.9 a
Talladega Syngenta 163 b-f 281 b-e 937 a-c 1380 a-e 5.9 b-d 84.7 a-c
FL 91 Seminis 102 d-g 198 c-f 924 a-d 1224 a-f 6.1 bc 86.6 ab
BHN 602 BHN 84 fg 214 c-f 922 a-d 1220 a-f 6.4 ab 81.4 a-c
BHN 640 BHN 178 b-f 288 a-e 674 c-g 1139 b-f 5.6 c-e 76.7 bc
Sebring Syngenta 137 c-g 298 a-d 695 b-g 1130 b-f 5.7 c-e 88.8 a
NBT 10827 Nunhems 196 b-e 341 a-c 566 c-h 1103 b-f 5.3 d-g 78.0 a-c
FL 47 Seminis 129 d-g 258 c-f 566 c-h 1103 b-f 5.9 b-d 82.3 a-c
Indy Syngenta 189 b-e 247 c-f 644 c-g 1080 b-f 5.3 d-g 77.6 a-c
NBT 10828 Nunhems 202 b-d 309 a-d 511 d-h 1023 b-f 5.3 d-g 84.8 a-c
NBT 10836 Nunhems 154 b-g 248 c-f 603 c-g 1004 b-f 5.5 c-f 83.3 a-c
8153 GCREC 250 ab 325 a-c 392 f-h 967 c-f 5.0 f-h 80.5 a-c
7964 GCREC 159 b-f 256 c-f 548 c-h 962 c-f 5.4 d-g 76.7 bc
BHN 601 BHN 117 d-g 226 c-f 572 c-g 915 d-f 5.6 c-e 79.0 a-c
NRT 6741 Nunhems 152 b-g 226 c-f 516 d-h 894 d-f 5.4 d-g 73.8 c
Crista Harris Moran 104 d-g 203 c-f 524 d-h 830 ef 5.9 b-d 81.0 a-c
NRT 6758 Nunhems 147 b-g 260 c-f 400 f-h 806 f 5.2 e-g 79.8 a-c
Amelia Harris Moran 51 g 134 f 591 c-g 777 f 5.9 b-d 73.7 c
BHN 669 BHN 201 b-e 284 b-e 290 gh 775 f 4.9 gh 80.4 a-c
NBT 10826 Nunhems 315 a 270 c-f 164 h 749 f 4.5 h 87.5 ab
BHN 444 BHN 112 d-g 155 ef 423 e-h 690 f 5.5 c-f 74.0 c

z Mean separation by Duncan's multiple range test, 5 % level.
Comments: In-row spacing 20 in., between row spacing 6 ft., trickle irrigation under black polyethylene mulch, fertilizer applied 195-60-
195 Ibs/A N-P205-K20. Seeded: 29 June 2005. Transplanted 29 July 2005. Harvested: 18 Oct 2 Nov 2005, 3 harvests; Soil: Orangeburg
loamy fine sand


Water Management for Tomato

E.H. Simonne
UF/IFAS Horticultural Sciences Department, Gainesville

esimonne@ufl. edu

Water and nutrient management are important aspects of
tomato production. Water is used for wetting fields before land
preparation, transplant establishment, and irrigation. The objective
of this article is to provide an overview of recommendations for
tomato irrigation in Florida. Recommendations in this article
should be considered together with those presented in the
"Fertilizer and nutrient management for tomato", also included
in this publication.
Irrigation is used to replace the amount of water lost by
transpiration and evaporation. This amount is also called crop
evapotranspiration (ETc). Irrigation scheduling is used to apply
the proper amount of water to a tomato crop at the proper time.
The characteristics of the irrigation system, tomato crop needs,
soil properties, and atmospheric conditions must all be considered
to properly schedule irrigations. Poor timing or insufficient
water application can result in crop stress and reduced yields
from inappropriate amounts of available water and/or nutrients.
Excessive water applications may reduce yield and quality, are a
waste of water, and increase the risk of nutrient leaching
A wide range of irrigation scheduling methods is used in
Florida, with corresponding levels of water managements (Table
1). The recommend method to schedule irrigation for tomato is
to use together an estimate of the tomato crop water requirement
that is based on plant growth, a measurement of soil water status
and a guideline for splitting irrigation (water management level
5 in Table 1; Table 2). The estimated water use is a guideline
for irrigating tomatoes. The measurement of soil water tension
is useful for fine tuning irrigation. Splitting irrigation events is
necessary when the amount of water to be applied is larger than
the water holding capacity of the root zone.

Tomato Water Requirement. Tomato water requirement
(ETc) depends on stage of growth, and evaporative demand. ETc
can be estimated by adjusting reference evapotranspiration (ETo)
with a correction factor call crop factor (Kc; equation [1]). Because
different methods exist for estimating ETo, it is very important
to use Kc coefficients which were derived using the same ETo
estimation method as will be used to determine ETc. Also, Kc
values for the appropriate stage of growth and production system
(Table 3) must be used.
By definition, ETo represents the water use from a uniform
green cover surface, actively growing, and well watered (such as
a turf or grass covered area). ETo can be measured on-farm using
a small weather station. When daily ETo data are not available,
historical daily averages of Penman-method ETo can be used
(Table 4). However, these long-term averages are provided as
guidelines since actual values may fluctuate by as much as 25%,
either above the average on hotter and drier than normal days, or
below the average on cooler or more overcast days than normal. As
a result, SWT or soil moisture should be monitored in the field.

Eq. [1] Crop water requirement =
Crop coefficient x Reference evapotranspiration
ETc = Kc x ETo

Tomato crop water requirement may also be estimated from
Class A pan evaporation using:

Eq. [2] Crop water requirement =
Crop factor x Class A pan evaporation
ETc = CF x Ep

Typical CF values for fully-grown tomato should not
exceed 0.75 (Locascio and Smajstrla, 1996).

A third method for estimated tomato crop water requirement
is to use modified Bellani plates also known as atmometers. A
common model of atmometer used in Florida is the ET This
device consists of a canvas-covered ceramic evaporation plate
mounted on a water reservoir. The green fabric creates a diffusion
barrier that controls evaporation at a rate similar to that of well
water plants. Water loss through evaporation can be read on a
clear sight tube mounted on the side of the device. Evaporation
from the ETgag (ETg) was well correlated to ETo except on rainy
days, but overall, the ETgage tended to underestimate ETo (Irmak et
al., 2005). On days with rainfall less than 0.2 inch/day, ETo can be
estimated from ETg as: ETo = 1.19 ETg. When rainfall exceeded
0.2inch/day, rain water wets the canvas which interferes with the
flow of water out of the atmometers, and decreases the reliability
of the measurement.

Tomato Irrigation Requirement. Irrigation systems are
generally rated with respect to application efficiency (Ea), which
is the fraction of the water that has been applied by the irrigation
system and that is available to the plant for use. In general, Ea
is 20% to 70% for seepage irrigation and 90% to 95% for drip
irrigation. Applied water that is not available to the plant may have
been lost from the crop root zone through evaporation, leaks in the
pipe system, surface runoff, subsurface runoff, or deep percolation
within the irrigated area. When dual drip/seepage irrigation
systems are used, the contribution of the seepage system needs to
be subtracted from the tomato irrigation requirement to calculate
the drip irrigation need. Otherwise, excessive water volume will
be systematically applied. Tomato irrigation requirement are
determined by dividing the desired amount of water to provide to
the plant (ETc), by Ea as a decimal fraction (Eq. [3]).

Eq. [3] Irrigation requirement =
Crop water requirement /Application efficiency
IR = ETc/Ea

Irrigation scheduling for tomato. For seepage irrigated
crops, irrigation scheduling recommendations consist of
maintaining the water table near the 18-inch depth shortly after
transplanting and near the 24- inch depth thereafter (Stanley and


Clark, 2003). The actual depth of the water table may be monitored
with shallow observation wells (Smaj strla, 1997).
Irrigation scheduling for drip irrigated tomato typically
consists in daily applications of ETc, estimated from Eq. [1] or
[2] above. In areas where real-time weather information is not
available, growers use the "1,000 gal/acre/day/string" rule for
drip-irrigated tomato production. As the tomato plants grow from
1 to 4 strings, the daily irrigation volumes increase from 1,000 gal/
acre/day to 4,000 gal/acre/day. On 6-ft centers, this corresponds
to 15 gal/1001bf/day and 60 gal/1001bf/day for 1 and 4 strings,

Soil Moisture Measurement. Soil water tension (SWT)
represents the magnitude of the suction (negative pressure) the
plant roots have to create to free soil water from the attraction of
the soil particles, and move it into its root cells. The dryer the soil,
the higher the suction needed, hence, the higher SWT. SWT is
commonly expressed in centibars (cb) or kiloPascals (kPa; Icb =
IkPa). For tomatoes grown on the sandy soils of Florida, SWT in
the rooting zone should be maintained between 6 (field capacity)
and 15 cb.
The two most common tools available to measure SWT in
the field are tensiometers and time domain reflectometry (TDR)
probes, although other types of probes are now available (Mufioz-
Carpena, 2004). Tensiometers have been used for several years
in tomato production. A porous cup is saturated with water, and
placed under vacuum. As the soil water content changes, water
comes in or out of the porous cup, and affects the amount of
vacuum inside the tensiometer. Tensiometer readings have been
successfully used to monitor SWT and schedule irrigation for
tomatoes. However, because they are fragile and easily broken
by field equipment, many growers are reluctant to use them. In
addition, readings are not reliable when the tensiometer dries, or
when the contact between the cup and the soil is lost. Depending
on the length of the access tube, tensiometers cost between $40
and $80 each. Tensiometers can be reused as long as they are
maintained properly and remain undamaged.
It is necessary to monitor SWT at two soil depths when
tensiometers are used. A shallow 6-in depth is useful at the
beginning of the season when tomato roots are near that depth.
A deeper 12-in depth is used to monitor SWT during the rest of
the season. Comparing SWT at both depth is useful to understand
the dynamics of soil moisture. When both SWT are within the
4-8 cb range (close to field capacity), this means that moisture is
plentiful in the rooting zone. This may happen after a large rain,
or when tomato water use is less than irrigation applied. When the
6-in SWT increases (from 4-8 cb to 10-15cb) while SWT at 12-in
remains within 4-8 cb, the upper part of the soil is drying, and it
is time to irrigate. If the 6-in SWT continues to rise above 25cb, a
water stress will result; plants will wilt, and yields will be reduced.
This should not happen under adequate water management.
A SWT at the 6-in depth remaining with the 4-8 cb range,
but the 12-in reading showing a SWT of 20-25 cb suggest that
deficit irrigation has been made: irrigation has been applied to re-
wet the upper part of the profile only. The amount of water applied
was not enough to wet the entire profile. If SWT at the 12-in depth
continues to increase, then water stress will become more severe

and it will become increasingly difficult to re-wet the soil profile.
The sandy soils of Florida have a low water holding capacity.
Therefore, SWT should be monitored daily and irrigation applied
at least once daily. Scheduling irrigation with SWT only can be
difficult at times. Therefore, SWT data should be used together
with an estimate of tomato water requirement
Times domain reflectometry (TDR) is not a new method
for measuring soil moisture but its use in vegetable production
has been limited in the past. The recent availability of inexpensive
equipment ($400 to $550/unit) has increased the potential of this
method to become practical for tomato growers. A TDR unit is
comprised of three parts: a display unit, a sensor, and two rods.
Rods may be 4 inches or 8 inches in length based on the depth of
the soil. Long rods may be used in all the sandy soils of Florida,
while the short rods may be used with the shallow soils of Miami-
Dade county.
The advantage of TDR is that probes need not being buried
permanently, and readings are available instantaneously. This
means that, unlike the tensiometer, TDR can be used as a hand-
held, portable tool.
TDR actually determines percent soil moisture (volume of
water per volume of soil). In theory, a soil water release curve
has to be used to convert soil moisture in to SWT. However,
because TDR provides an average soil moisture reading over the
entire length of the rod (as opposed to the specific depth used for
tensiometers), it is not practical to simply convert SWT into soil
moisture to compare readings from both methods. Preliminary
tests with TDR probes have shown that best soil monitoring may
be achieved by placing the probe vertically, approximately 6
inches away from the drip tape on the opposite side of the tomato
plants. For fine sandy soils, 9% to 15% appears to be the adequate
moisture range. Tomato plants are exposed to water stress when
soil moisture is below 8%. Excessive irrigation may result in soil
moisture above 16%.

Guidelines for Splitting Irrigation. For sandy soils, a
one square foot vertical section of a 100-ft long raised bed can
hold approximately 24 to 30 gallons of water (Table 5). When
drip irrigation is used, lateral water movement seldom exceeds 6
to 8 inches on each side of the drip tape (12 to 16 inches wetted
width). When the irrigation volume exceeds the values in table 5,
irrigation should be split into 2 or 3 applications. Splitting will
not only reduce nutrient leaching, but it will also increase tomato
quality by ensuring a more continuous water supply. Uneven
water supply may result in fruit cracking.

Units for Measuring Irrigation Water. When overhead
and seepage irrigation were the dominant methods of irrigation,
acre-inches or vertical amounts of water were used as units for
irrigations recommendations. There are 27,150 gallons in one
acre-inch; thus, total volume was calculated by multiplying the
recommendation expressed in acre-inch by 27,150. This unit
reflected quite well the fact that the entire field was wetted.
Acre-inches are still used for drip irrigation, although the
entire field is not wetted. This section is intended to clarify the
conventions used in measuring water amounts for drip irrigation.
In short, water amounts are handled similarly to fertilizer amounts,

-41 -

i.e., on an acre basis. When an irrigation amount expressed in
acre-inch is recommended for plasticulture, it means that the
recommended volume of water needs to be delivered to the row
length present in a one-acre field planted at the standard bed
spacing. So in this case, it is necessary to know the bed spacing
to determine the exact amount of water to apply. In addition, drip
tape flow rates are reported in gallons/hour/emitter or in gallons/
hour/i 00 ft of row. Consequently, tomato growers tend to think in
terms of multiples of 100 linear feet of bed, and ultimately convert
irrigation amounts into duration of irrigation. It is important to
correctly understand the units of the irrigation recommendation in
order to implement it correctly.

Example. How long does an irrigation event need to last if
a tomato grower needs to apply 0.20 acre-inch to a 2-acre tomato
field. Rows are on 6-ft centers and a 12-ft spray alley is left
unplanted every six rows? The drip tape flow rate is 0.30 gallons/
hour/emitter and emitters are spaced 1 foot apart.

1. In the 2-acre field, there are 14,520 feet of bed (2 x
43,560/6). Because of the alleys, only 6/8 of the field is
actually planted. So, the field actually contains 10,890
feet of bed (14,520x 6/8).

2. A 0.20 acre-inch irrigation corresponds to 5,430 gallons
applied to 7,260 feet of row, which is equivalent to
75gallons/100feet (5,430/72.6).

3. The drip tape flow rate is 0.30 gallons/hr/emitter which is
equivalent to 30 gallons/hr/100feet. It will take 1 hour to
apply 30 gallons/100ft, 2 hours to apply 60 gallons/100ft,
and 2.5 hours to apply 75 gallons. The total volume
applied will be 8,168 gallons/2-acre (75 x 108.9).

Irrigation and Best Management Practices. As an effort
to clean impaired water bodies, federal legislation in the 70's,
followed by state legislation in the 90's and state rules since 2000
have progressively shaped the Best Management Practices (BMP)
program for vegetable production in Florida. Section 303(d) of
the Federal Clean Water Act of 1972 required states to identify
impaired water bodies and establish Total Maximum Daily Loads
(TMDL) for pollutants entering these water bodies. In 1987, the
Florida legislature passed the Surface Water Improvement and
Management Act requiring the five Florida water management
districts to develop plans to clean up and preserve Florida lakes,
bays, estuaries, and rivers. In 1999, the Florida Watershed
Restoration Act defined a process for the development of TMDLs.
More recently, the "Florida vegetable and agronomic crop water
quality/quantityBestManagementPractices" manual was adopted
by reference and by rule 5M-8 in the Florida Administrative Code
on Feb.9, 2006 (FDACS, 2005). The manual which is available
at www.floridaagwaterpolicy.com, provides background on the
state-wide BMP program for vegetables, lists all the possible
BMPs, provides a selection mechanism for building a customized
BMP plan, outlines record-keeping requirements, and explains
how to participate in the BMP program. By definition, BMPs are
specific cultural practices that aim at reducing nutrient load while

maintaining or increasing productivity. Hence, BMPs are tools to
achieve the TMDL. Vegetable growers who elect to participate in
the BMP program receive three statutory benefits: (1) a waiver
of liability from reimbursement of cost and damages associated
with the evaluation, assessment, or remediation of contamination
of ground water (Florida Statutes 376.307); (2) a presumption of
compliance with water quality standards (F.S. 403.067 (7)(d)),
and (3); an eligibility for cost-share programs (F.S. 570.085 (1)).

BMPs cover all aspects of tomato production: pesticide
management, conservation practices and buffers, erosion control
and sediment management, nutrient and irrigation management,
water resources management, and seasonal or temporary farming
operations. The main water quality parameters of importance
to tomato and pepper production and targeted by the BMPs are
nitrate, phosphate and total dissolved solids concentration in
surface or ground water. All BMPs have some effect on water
quality, but nutrient and irrigation management BMPs have a
direct effect on it.

FDACS. 2005. Florida Vegetable and Agronomic Crop Water
Quality and Quantity BMP Manual. Florida Department of
Agriculture and Consumer Services.
http ://www. floridaagwaterpolicy. com/PDFs/BMPs/

Irmak, S., M. Asce, M.D. Dukes, and J.M. Jacobs. 2005. Using
modified Bellani plate evapotranspiration gauges to estimate short
canopy reference evapotranspiration.J. Irr. Drainage Eng. (2):164-

Locascio, S.J. and A.G. Smajstrla. 1996. Water application
scheduling by pan evaporation for drip-irrigated tomato. J. Amer.
Soc. Hort. Sci. 121(1):63-68

Mufioz-Carpena, R. 2004. Field devices for monitoring soil water
content. EDIS Bul. 343. http://edis.ifas.ufl.edu/AE266.

Simonne, E.H., D.W. Studstill, R.C. Hochmuth, G. McAvoy, M.D.
Dukes and S.M. Olson. 2003. Visualization of water movement in
mulched beds with injections of dye with drip irrigation. Proc.
Fla. State Hort. Soc. 116:88-91.

Simonne, E.H., D.W. Studstill, T.W. Olczyk, and R. Munoz-
Carpena. 2004. Water movement in mulched beds in a rocky soil
of Miami-Dade county. Proc. Fla. State Hort. Soc 117:68-70.

Simonne, E. and B. Morgan. 2005. Denitrification in seepage
irrigated vegetable fields in South Florida, EDIS, HS 1004, http://

Simonne, E.H., D.W. Studstill, R.C. Hochmuth, J.T. Jones
and C.W. Starling. 2005. On-farm demonstration of soil water
movement in vegetables grown with plasticulture, EDIS, HS
1008, http://edis.ifas.ufl.edu/HS251.


Smajstrla, A.G. 1997. Simple water level indicator for seepage Stanley, C.D. and G.A. Clark. 2003. Effect of reduced water table
irrigation. EDIS Circ. 1188, http://edis.ifas.ufl.edu/AE085. and fertility levels on subirrigated tomato production in Southwest
Florida. EDIS SL-210, http://edis.ifas.ufl.edu/SS429.

Table 1. Levels of water management and corresponding irrigation scheduling method for tomato.

Water Management
Level Rating

Irrigation scheduling method

Guessing (irrigate whenever)
Using the "feel and see" method
Using systematic irrigation (example: 2 hrs every day)

Intermediate Using a soil moisture measuring tool to start irrigation

4 Advanced

5 Recommended

Using a soil moisture measuring tool to schedule irrigation and apply amounts based on a budgeting
Using together a water use estimate based on tomato plant stage of growth, a measurement of soil
water moisture, determining rainfall contribution to soil moisture, and having a guideline for splitting
irrigation. In addition, BMPs have some record keeping requirements

Table 2. Summary of irrigation management guidelines for tomato.

1- Target water
application rate

2- Fine tune application
with soil moisture

Irrigation system7



Keep water table between 18 and 24 inch depth Historical weather data or crop evapotranspiration (ETc)
calculated from reference ET or Class A pan evaporation
Monitor water table depth with observation wells Maintain soil water tension in the root zone between 8
and 15 cbar

3- Determine the Typically, 1 inch rainfall raises the water table by
contribution of rainfall 1 foot

4- Rule for splitting

5-Record keeping

Not applicable

Irrigation amount applied and total rainfall
Days of system operation

Poor lateral water movement on sandy and rocky soils
limits the contribution of rainfall to crop water needs to
(1) foliar absorption and cooling of foliage and (2) water
funneled by the canopy through the plan hole.
Irrigations greater than 12 and 50 gal/100ft (or 30 min
and 2 hrs for medium flow rate) when plants are small
and fully grown, respectively are likely to push the water
front being below the root zone
Irrigation amount applied and total rainfall received"
Daily irrigation schedule

z Efficient irrigation scheduling also requires a properly designed and maintained irrigation systems
Y Practical only when a spodic layer is present in the field
x On deep sandy soils
w Required by the BMPs


Very low

Table 3. Crop coefficient estimates (Kc) for tomatoz.

Tomato Growth Stage Plasticulture
1 0.30
2 0.40
3 0.90
4 0.90
5 0.75

z Actual values will vary with time of planting, length of growing season and other site-specific factors. Kc values should be used with
ETo values in Table 2 to estimated crop evapotranspiration (ETc)

Table 4. Historical Penman-method reference ET (ETo) for four Florida locations (in gallons per acre per day)

Month Tallahassee Tampa West Palm Beach Miami
January 1,630 2,440 2,720 2,720
February 2,440 3,260 3,530 3,530
March 3,260 3,800 4,340 4,340
April 4,340 5,160 5,160 5,160
May 4,890 5,430 5,160 5,160
June 4,890 5,430 4,890 4,890
July 4,620 4,890 4,890 4,890
August 4,340 4,620 4,890 4,620
September 3,800 4,340 4,340 4,070
October 2,990 3,800 3,800 3,800
November 2,170 2,990 3,260 2,990
December 1,630 2,170 2,720 2,720
assuming water application over the entire area with 100% efficiency

Table 5. Estimated maximum water application (in gallons per acre and in gallons/ 0fb) in one irrigation event for tomato
grown on 6-ft centers (7,260 linear bed feet per acre) on sandy soil (available water holding capacity 0.75 in/ ft and
50% soil water depletion). Split irrigations may be required during peak water requirement.

Wetting width Gal/100ft to wet Gal/10Oft to wet Gal/10Oft to wet Gal/acre to wet Gal/acre to wet Gal/acre to wet
(ft) depth of 1 ft depth of 1.5 ft depth of 2 ft depth of 1 ft depth of 1.5ft depth of 2 ft
1.0 24 36 48 1,700 2,600 3,500
1.5 36 54 72 2,600 3,900 5,200


Fertilizer and Nutrient Management
for Tomato

E.H. Simonne
UF/IFAS Horticultural Sciences Department, Gainesville

esimonne@ufl. edu

Fertilizer andnutrient management are essential components
of successful commercial tomato production. This article presents
the basics of nutrient management for the different production
systems used for tomato in Florida.

Calibrated Soil Test: Taking the Guesswork Out of
Fertilization. Prior to each cropping season, soil tests should
be conducted to determine fertilizer needs and eventual pH
adjustments. Obtain a UF/IFAS soil sample kit from the local
agricultural Extension agent or from a reputable commercial
laboratory for this purpose. If a commercial soil testing laboratory
is used, be sure the lab uses methodologies calibrated and
extractants suitable for Florida soils. When used with the percent
sufficiency philosophy, routine soil testing helps adjust fertilizer
applications to plant needs and target yields. In addition, the use of
routine calibrated soil tests reduces the risk of over-fertilization.
Over fertilization reduces fertilizer efficiency and increases the
risk of groundwater pollution. Systematic use of fertilizer without
a soil test may also result in crop damage from salt injury.
The crop nutrient requirements of nitrogen, phosphorus,
and potassium (designated in fertilizers as N-P20 -K20) represent
the optimum amounts of these nutrients needed for maximum
tomato production (Table 1). Fertilizer rates are provided on
a per-acre basis for tomato grown on 6-ft centers. Under these
conditions, there are 7,260 linear feet of tomato row in an acre.
When different row spacings are used, it is necessary to adjust
fertilizer application accordingly. For example, a 200 lb/A N rate
on 6-ft centers is the same as 240 lb/A N rate on 5-ft centers and
a 170 lb/A N rate on 7-ft centers. This example is for illustration
purposes, and only 5 and 6 ft centers are commonly used for
tomato production in Florida.
Fertilizer rates can be simply and accurately adjusted
to row spacings other than the standard spacing (6-ft centers)
by expressing the recommended rates on a 100 linear bed feet
(Ibf) basis, rather than on a real-estate acre basis. For example,
in a tomato field planted on 7-ft centers with one drive row
every six rows, there are only 5,333 lbf/A (6/7 x 43,560 / 7). If
the recommendation is to inject 10 lb of N per acre (standard
spacing), this becomes 10 lb N/7,260 lbf or 0.14 lb N/100 lbf
Since there are 5,333 lbf/acre in this example, then the adjusted
rate for this situation is 7.46 lb/acre N (0.14 x 53.33). In other
words, an injection of 10 lb N to 7,260 lbf is accomplished by
injecting 7.46 lb N to 5,333 lbf.

Liming. The optimum pH range for tomatoes is 6.0 and
6.5. This is the range for which the availability of all the essential
nutrients is highest. Fusarium wilt problems are reduced by liming
within this range, but it is not advisable to raise the pH above 6.5
because of reduced micronutrient availability. In areas where soil

pH is basic (>7.0), micronutrient deficiencies may be corrected
by foliar sprays.
Calcium and magnesium levels should be corrected
according to the soil test. If both elements are "low",, and lime
is needed, then broadcast and incorporate dolomitic limestone
(CaCO3, MgCO3). Where calcium alone is deficient, "hi-cal"
(CaCO3) limestone should be used. Adequate calcium is important
for reducing the severity of blossom-end rot. Research shows that
a Mehlich-I (double-acid) index of 300 to 350 ppm Ca would be
indicative of adequate soil-Ca. On limestone soils, add 30-40 lb/
acre of magnesium in the basic fertilizer mix. It is best to apply
lime several months prior to planting. However, if time is short, it
is better to apply lime any time before planting than not to apply
it at all. Where the pH does not need modification, but magnesium
is low, apply magnesium sulfate or potassium-magnesium sulfate
with the fertilizer.
Changes in soil pH may take several weeks to occur when
carbonate-based liming materials are used (calcitic or dolomitic
limestone). Oxide-based liming materials (quick lime -CaO- or
dolomitic quick lime -CaO, MgO-) are fast reacting and rapidly
increase soil pH. Yet, despite these advantages, oxide-based
liming materials are more expensive than the traditional liming
materials, and therefore are not routinely used.
The increase in pH induced by liming materials is NOT
due to the presence of calcium or magnesium. Instead, it is the
carbonate ("CO3") and oxide ("O") part of CaCO3 and CaO,
respectively, that raises the pH. Through several chemical
reactions that occur in the soil, carbonates and oxides release OH-
ions that combine with HI to produce water. As large amounts of
HI react, the pH rises. A large fraction of the Ca and/or Mg in the
liming materials gets into solution and binds to the sites that are
freed by HI that have reacted with OH-.

Blossom-End Rot. Growers may have problems with
blossom-end-rot, especially on the first or second fruit clusters.
Blossom-end rot (BER) is a Ca deficiency in the fruit, but is often
more related to plant water stress than to Ca concentrations in the
soil. This is because Ca movement in the plant occurs with the
water (transpiration) stream. Thus, Ca moves preferentially to the
leaves. As a maturing fruit is not a transpiring organ, most of the
Ca is deposited during early fruit growth.
Once BER symptoms develop on a tomato fruit, they
cannot be alleviated on this fruit. Because of the physiological
role of Ca in the middle lamella of cell walls, BER is a structural
and irreversible disorder. Yet, the Ca nutrition of the plant can
be altered so that the new fruits are not affected. BER is most
effectively controlled by attention to irrigation and fertilization,
or by using a calcium source such as calcium nitrate when soil Ca
is low. Maintaining adequate and uniform amounts of moisture in
the soil are also keys to reducing BER potential.
Factors that impair the ability of tomato plants to obtain
water will increase the risk of BER. These factors include
damaged roots from flooding, mechanical damage or nematodes,
clogged drip emitters, inadequate water applications, alternating


dry-wet periods, and even prolonged overcast periods. Other
causes for BER include high fertilizer rates, especially potassium
and nitrogen.
Calcium levels in the soil should be adequate when the
Mehlich-1 index is 300 to 350 ppm, or above. In these cases,
added gypsum (calcium sulfate) is unlikely to reduce BER. Foliar
sprays of Ca are unlikely to reduce BER because Ca does not
move out of the leaves to the fruit.

Gray Wall. Blotchy ripening (also called gray wall) of
tomatoes is characterized by white or yellow blotches that appear
on the surface of ripening tomato fruits, while the tissue inside
remains hard. The affected area is usually on the upper portion
of the fruit. The etiology of this disorder has not been formally
established, but it is often associated with high N and/or low K,
and aggravated by excessive amount of N. This disorder may be
at times confused with symptoms produced by the tobacco mosaic
virus. Gray wall is cultivar specific and appears more frequently
on older cultivars. The incidence of gray wall is less with drip
irrigation where small amounts of nutrients are injected frequently,
than with systems where all the fertilizer is applied pre-plant.

Micronutrients. For virgin, acidic sandy soils, or sandy
soils where a proven need exists, a general guide for fertilization
is the addition of micronutrients (in elemental lb/A) manganese
-3, copper -2, iron -5, zinc -2, boron -2, and molybdenum -0.02.
Micronutrients may be supplied from oxides or sulfates. Growers
using micronutrient-containing fungicides need to consider these
sources when calculating fertilizer micronutrient needs.
Properly diagnosed micronutrient deficiencies can often be
corrected by foliar applications of the specific micronutrient. For
most micronutrients, a very fine line exists between sufficiency
and toxicity. Foliar application of major nutrients (nitrogen,
phosphorus, or potassium) has not been shown to be beneficial
where proper soil fertility is present.

Mulch Production with Seepage Irrigation. Under this
system, the crop may be supplied with all of its soil requirements
before the mulch is applied (Table 1). It is difficult to correct a
deficiency after mulch application, although a liquid fertilizer
injection wheel can facilitate sidedressing through the mulch. The
injection wheel will also be useful for replacing fertilizer under
the used plastic mulch for double-cropping systems. A general
sequence of operations for the full-bed plastic mulch system is:

1. Land preparation, including development of irrigation
and drainage systems, and liming of the soil, if needed.

2. Application of "cold" mix comprised of 10% to 20% of
the total nitrogen and potassium seasonal requirements
and all of the needed phosphorus and micronutrients.
The cold mix can be broadcast over the entire area prior
to bedding and then incorporated. During bedding, the
fertilizerwill be gathered into the bed area.An alternative
is to use a "modified broadcast" technique for systems
with wide bed spacings. Use of modified broadcast

or banding techniques can increase phosphorus and
micronutrient efficiencies, especially on alkaline (basic)

3. Formation of beds, incorporation of herbicide, and
application of mole cricket bait.

4. The remaining 80% to 90% of the nitrogen and
potassium is placed in narrow bands 9 to 10 inches to
each side of the plant row in furrows. This "hot mix"
fertilizer should be placed deep enough in the grooves
for it to be in contact with moist bed soil. Bed presses
are modified to provide the groove. Only water-soluble
nutrient sources should be used for the banded fertilizer.
A mixture of potassium nitrate (or potassium sulfate or
potassium chloride), calcium nitrate, and ammonium
nitrate has proven successful.

5. Fumigation, pressing of beds, and mulching. This
should be done in one operation, if possible. Be sure
that the mulching machine seals the edges of the mulch
adequately with soil to prevent fumigant escape.

Water management with the seep irrigation system is
critical to successful crops. Use water-table monitoring devices
and/or tensiometers in the root zone to help provide an adequate
water table but no higher than required for optimum moisture. It
is recommended to limit fluctuations in water table depth since
this can lead to increased leaching losses of plant nutrients.

Mulched Production with Drip Irrigation. Where drip
irrigation is used, drip tape or tubes should be laid 1 to 2 inches
below the bed soil surface prior to mulching. This placement helps
protect tubes from mice and cricket damage. The drip system is an
excellent tool with which to fertilize tomato. Where drip irrigation
is used, apply all phosphorus and micronutrients, and 20 percent
to 40 percent of total nitrogen and potassium preplant in the bed.
Apply the remaining nitrogen and potassium through the drip
system in increments as the crop develops.
Successful crops have resulted where the total amounts ofN
and K20 were applied through the drip system. Some growers find
this method helpful where they have had problems with soluble-
salt bur. This approach would be most likely to work on soils
with relatively high organic matter and some residual potassium.
However, it is important to begin with rather high rates of N and
K20 to ensure young transplants are established quickly. In most
situations, some preplant N and K fertilizers are needed.
Suggested schedules for nutrient injections have been
successful in both research and commercial situations, but might
need slight modifications based on potassium soil-test indices and
grower experience (Table 1).

Sources of N-P20,-K2O. About 30% to 50% of the total
applied nitrogen should be in the nitrate form for soil treated with
multi-purpose fumigants and for plantings in cool soil. Controlled-
release nitrogen sources may be used to supply a portion of the
nitrogen requirement. One-third of the total required nitrogen can


be supplied from sulfur-coated urea (SCU), isobutylidene diurea
(IBDU), or polymer-coated urea (PCU) fertilizers incorporated
in the bed. Nitrogen from natural organic and most controlled-
release materials is initially in the ammoniacal form, but is rapidly
converted into nitrate by soil microorganisms.
Normal superphosphate and triple superphosphate are
recommended for phosphorus needs. Both contribute calcium and
normal superphosphate contributes sulfur.
All sources of potassium can be used for tomatoes.
Potassium sulfate, sodium-potassium nitrate, potassium nitrate,
potassium chloride, monopotassium phosphate, and potassium-
magnesium sulfate are all good K sources. If the soil test predicted
amounts of K20 are applied, then there should be no concern for
the K source or its associated salt index.

Sap Testing and Tissue Analysis. While routine soil
testing is essential in designing a fertilizer program, sap tests and/
or tissue analyses reveal the actual nutritional status of the plant.
Therefore these tools complement each other, rather than replace
one another.
When drip irrigation is used, analysis of tomato leaves for
mineral nutrient content (Table 2) or quick sap test (Table 3) can
help guide a fertilizer management program during the growing
season or assist in diagnosis of a suspected nutrient deficiency.
Experience has shown that these tools are of limited use for
routine analysis with seepage irrigated crops. However, they still
may be used when deficiencies/toxicities are suspected.
For both nutrient monitoring tools, the quality and reliability
of the measurements are directly related with the quality of the
sample. A leaf sample should contain at least 20 most recently,
fully developed, healthy leaves. Select representative plants, from
representative areas in the field.

Supplemental Fertilizer Applications. In practice,
supplemental fertilizer applications allow vegetable growers to
numerically apply fertilizer rates higher than the standard UF/
IFAS recommended rates when growing conditions require doing
so. Applying additional fertilizer under the three circumstances
described in Table 1 (leaching rain, 'low' foliar content, and
extended harvest season) is part of the current UF/IFAS fertilizer
recommendations and nutrient BMPs.

Levels of Nutrient Management for Tomato Production.
Based on the growing situation and the level of adoption of the
tools and techniques described above, different levels of nutrient
management exist for tomato production in Florida. Successful
production and nutrient BMPs requires management levels of 3
or above (Table 4).

Florida Department of Agriculture and Consumer Services.
2005. Florida Vegetable and Agronomic Crop Water Quality and
Quantity BMP Manual.

Gilbert, C.A and E.H. Simonne. 2005. Update and outlook
for 2005 of Florida's BMP program for vegetable crops, EDIS
HS1013, http://edis.ifas.ufl.edu/HS256.

Hochmuth, G. 1994. Plant petiole sap-testing for vegetable crops.
Univ. Fla. Coop. Ext. Circ. 1144, http://edis.ifas.ufl.edu/cv004

Hochmuth, G., D. Maynard, C. Vavrina, E. Hanlon, and E.
Simonne. 2004. Plant tissue analysis and interpretation for
vegetable crops in Florida. EDIS http://edis.ifas.ufl.edu/EP081.

Maynard, D.N., and G.J. Hochmuth. 1997. Knott's Handbook for
vegetable growers. 4h ed. Wiley Interscience, New York.

Olson, S.M., D.N. Maynard, G.J. Hochmuth, C.S. Vavrina, W.M.
Stall, T.A. Kucharek, S.E. Webb, T.G. Taylor, S.A. Smith, and
E.H. Simonne. 2004. Tomato production in Florida, pp. 301-
316 In: S.M. Olson and E. Simonne (Eds.) 2004-2005 Vegetable
Production Handbook for Florida, Vance Pub., Lenexa, KS.

Simonne, E.H. and G.J. Hochmuth. 2004. Soil and fertilizer
management for vegetable production in Florida, pp. 3-16 In: S.M.
Olson and E. Simonne (Eds.) 2004-2005 Vegetable Production
Handbook for Florida, Vance Pub., Lenexa, KS.

Simonne, E., D. Studstill, B. Hochmuth, T. Olczyk, M. Dukes, R.
Munoz-Carpena, and Y. Li. 2002. Drip irrigation: The BMP era
- An integrated approach to water and fertilizer management in
Florida, EDIS HS917, http://edis.ifas.ufl.edu/HS172.

Simonne, E.H. and G.J. Hochmuth. 2003. Principles of irrigation
and fertilization management for vegetable crops grown in Florida
in the BMP era: Introduction. EDIS HS897, http://edis.ifas.ufl.
edu/HS 154.


Table 1. Fertilization recommendations for tomato grown in Florida on sandy soils testing very low in Mehlich-1 potassium


system Nutrient

Recommended base fertilizationz

Recommended supplemental fertilizationz

(Ib/A/day) Measured "low" Extended
Total Preplantv Weeks after transplanting" Leaching plant nutrient harvest
(Ib/A) (Ib/A) 1-2 3-4 5-11 12 13 rains content"- seasons

N 200 0-50 1.5 2.0 2.5 2.0

1.5 to 2 Ib/A/day
n/a for days
for 7dayst

1.5-2 Ib/A/day for
220 0-50 2.5 2.0 3.0 2.0 1.5 n/a

N 200 200" 0 0 0 0 0 30 Ib/A'

K,0 220 220v 0 0 0 0 0 20 Ib/A

30 Ib/A'

20 Ib/A'

1.5-2 Ib/A/

1.5-2 Ib/A/

30 Ib/Ap

20 Ib/Ap

z 1 A = 7,260 linear bed feet per acre (6-ft bed spacing); for soils testing "very low" in Mehlich 1 potassium (K20).
Y applied using the modified broadcast method (fertilizer is broadcast where the beds will be formed only, and not over the entire field).
Preplant fertilizer cannot be applied to double/triple crops because of the plastic mulch; hence, in these cases, all the fertilizer has to be
x This fertigation schedule is applicable when no N and K20 are applied preplant. Reduce schedule proportionally to the amount of N and
K20 applied preplant. Fertilizer injections may be done daily or weekly. Inject fertilizer at the end of the irrigation event and allow enough
time for proper flushing afterwards.
w For a standard 13 week-long, transplanted tomato crop grown in the Spring.
" Some of the fertilizer may be applied with a fertilizer wheel though the plastic mulch during the tomato crop when only part of the
recommended base rate is applied preplant. Rate may be reduced when a controlled-release fertilizer source is used.
"Plant nutritional status may be determined with tissue analysis or fresh petiole-sap testing, or any other calibrated method. The "low"
diagnosis needs to be based on UF/IFAS interpretative thresholds.
SPlant nutritional status must be diagnosed every week to repeat supplemental application.
s Supplemental fertilizer applications are allowed when irrigation is scheduled following a recommended method. Supplemental fertilization
is to be applied in addition to base fertilization when appropriate. Supplemental fertilization is not to be "applied "in advance" with the
preplant fertilizer.
rA leaching rain is defined as a rainfall amount of 3 inches in 3 days or 4 inches in 7 days.
4 Supplemental amount for each leaching rain
P Plant nutritional status must be diagnosed after each harvest before repeating supplemental fertilizer application.


beds, and

beds, and

Table 2. Deficient, adequate, and excessive nutrient concentrations for tomato [most-recently-matured (MRM) leaf (blade plus petiole)].

N P K Ca Mg S
--------------------------- % ----------------------------

Fe Mn Zn B Cu Mo
----------------------------- ppm ----------------

Tomato MRMzleaf 5-leafstage Deficient <3.0 0.3 3.0 1.0 0.3 0.3 40 30 25 20
Adequate range 3.05.0 0.30.6 3.05.0 1.02.0 0.30.5 0.30.8 40100 30100 2540 2040
High >5.0 0.6 5.0 2.0 0.5 0.8 100 100 40 40
MRMleaf Firstflower Deficient <2.8 0.2 2.5 1.0 0.3 0.3 40 30 25 20

Adequate Range 2.84.0 0.20.4 2.54.0 1.02.0 0.30.5 0.30.8 40100 30100 2540 2040
High >4.0 0.4 4.0 2.0 0.5 0.8 100 100 40 40
Toxic (>) 1500 300 250

MRMleaf set

First ripe
Tomato MRMleaf fruit

MRMleaf period

zMRM=Most recently matured leaf.

Deficient <2.5 0.2 2.5 1.0 0.25 0.3 40 30 20 20
Adequate Range 2.54.0 0.20.4 2.54.0 1.02.0 0.250.5 0.30.6 40100 30100 2040 2040
High >4.0 0.4 4.0 2.0 0.5 0.6 100 100 40 40
Toxic (>) 250

Deficient <2.0 0.2 2.0 1.0 0.25 0.3 40 30 20 20
Adequate Range 2.0 3.5 0.20.4 2.04.0 1.02.0 0.250.5 0.30.6 40100 30100 2040 2040
High >3.5 0.4 4.0 2.0 0.5 0.6 100 100 40 40

Deficient <2.0 0.2 1.5 1.0 0.25 0.3 40 30 20 20
Adequate Range 2.0 3.0 0.20.4 1.52.5 1.02.0 0.250.5 0.30.6 40100 30100 2040 2040
Hiah >3.0 0.4 2.5 2.0 0.5 0.6 100 100 40 40

5 0.2
515 0.20.6
15 0.6
5 0.2

515 0.20.6
15 0.6

5 0.2
510 0.20.6
10 0.6

5 0.2
510 0.20.6
10 0.6

5 0.2
510 0.20.6
10 0.6

Table 3. Recommended nitrate-N and K concentrations in fresh petiole sap for tomato.

Stage of growth
First buds
First open flowers
Fruits one-inch diameter
Fruits two-inch diameter
First harvest
Second harvest

Sap concentration (ppm)
1000-1200 3500-4000
600-800 3500-4000
400-600 3000-3500
400-600 3000-3500
300-400 2500-3000
200-400 2000-2500

Table 4. Progressive levels of nutrient management for tomato production.

Nutrient Management
Level Rating Description
0 None Guessing
1 Very low Soil testing and still guessing
2 Low Soil testing and implementing "a" recommendation
3 Intermediate Soil testing, understanding IFAS recommendations, and correctly implementing them
4 Advanced Soil testing, understanding IFAS recommendations, correctly implementing them, and monitoring
crop nutritional status
5 Recommended Soil testing, understanding IFAS recommendations, correctly implementing them, monitoring crop
nutritional status, and practice year-round nutrient management and/or following BMPs (including
one of the recommended irrigation scheduling methods).

SThese levels should be used together with the highest possible level of irrigation management


Tomato Fungicides and Other Disease
Management Products
(Updated June 2006)

Tim Momol and Laura Ritchie


Be sure to read a current product label before
applying any chemical.

Maximum Rate
Acre /

Manex4 F (maneb)

Dithane, Manzate or
Penncozeb 75 DFs
Maneb 80 WP
Dithane F 45 or
Manex II 4 FLs
Dithane M-45,
Penncozeb 80, or
Manzate 80 WPs
Maneb 75 DF
Equus 7204, Echo
720, Chloro Gold 720
6 FIs (chlorothalonil)

Echo 90 DF or
Equus 82.5DF
Ridomil Gold
Bravo 76.4 W
Amistar 80 DF

Cabrio 2.09 F


2.4 qts.

M3 3 Ibs.

16.8 qts.

22.4 Ibs.

Days to


Pertinent Diseases
or Pathogens
Early blight
Late blight
Gray leaf spot
Bacterial spot3

M3 3 Ibs 21 Ibs.

M3 2.4 pts. 16.8 qts.

M3 3 Ibs. 21 Ibs.

M3 3 Ibs. 22.4 Ibs.

M5 3 pts. or
2.88 pts.

M5 2.3 Ibs.

20.1 pts.

4/M5 3 Ibs. 121bs

2 ozs 12 ozs


See label

See label for details

2 Early blight
Late blight
Gray leaf spot
Target spot

14 Early blight
Late blight
Gray leaf spot
Target Spot
0 Early blight
Late blight
Powdery mildew

Use higher rates at fruit set and
lower rates before fruit set, see

Limit is 4 appl./crop, see label

Limit is 2 sequential appl. or 6
application total. Alternate or
tank mix with a multi-site effective
fungicide (FRAC code M), see label

6.2 fl.ozs. 37.2 fl.ozs. 0 Target spot
Buckeye rot
16 fl oz 96 fl oz 0


Maximum Rate
Fungicide Acre /
Chemical Group1 Applic. Season

Flint (trifloxystro-bin)

Ridomil Gold EC
Ridomil MZ 68
WP (mefenoxam +
Ridomil Gold Copper
64.8 W (mefenoxam
+ copper hydroxide)
JMS Stylet-Oil
(paraffinic oil)

Aliette 80 WDG

Bravo Ultrex

Bravo Weather Stik
Botran 75 W

Nova 40 W

11 16 oz

4 2 pts./
trtd. acre
4/M3 2.5 Ibs.


3 pts/trtd.
7.5 Ibs.

2 Ibs.

3 qts.

5 Ibs. 20 Ibs.

M5 2.6 Ibs. 18.3 Ibs

M5 2 34 pts. 20 pts

1 lb. 4 Ibs.

4 ozs. 1.25 Ibs.

Sulfur (many brands) M2


ManKocide 61.1 DF
(mancozeb + copper

Gavel 75DF
(mancozeb +

Previcur Flex

Curzate 60DF

1/3-3/4 oz 4 ozs.


5 Ibs.

112 Ibs.

M3/22 2.0 Ibs 16 Ibs

0.7-1.5 7.5 pints
( see
5 oz 30 oz per
12 month

Days to

Pertinent Diseases
or Pathogens
Early blight
Late blight
Gray leaf spot

28 Pythium diseases

5 Late blight

14 Late blight

Potato Virus Y
Tobacco Etch Virus
14 Phytophthora root rot

2 Early blight
Late blight
Gray leaf spot Target
spot Botrytis
Rhizoctonia fruit rot

10 Botrytis

0 Powdery mildew

1 Powdery mildew

14 Bacterial spot Bacterial
speck Tomato spotted
wilt a viral disease
(use in combination
of UV-reflective mulch
and vector thrips
specific insecticides).

See label for details

See label for details

Limit is 3 appl./crop, see label

Limit is 3 appl. /crop. Tank mix with
maneb or mancozeb fungicide, see
See label for restrictions and use
(e.g. use of 400 psi spray pressure)

Using potassium carbonate or
Diammonium phosphate, the spray
of Aliette should be raised to a pH
of 6.0 or above when applied prior
to or after copper fungicides, see
Use higher rates at fruit set, see

Greenhouse use only. Limit is 4
applications. Seedlings or newly
set transplants may be injured, see
Note that a 30 day plant back
restriction exists, see label
Follow label closely, it may cause
Do not use highest labeled rate
in early sprays to avoid a delayed
onset of harvest. See label for

5 Bacterial spot See label
Bacterial speck
Late blight
Early blight
Gray leaf spot
5 Buckeye rot Early blight See label
Gray leaf spot Late
Leaf mold

5 Late blight

3 Late Blight

Only in a tank mixture with
chlorothalonil, maneb or mancozeb,
see label

Do not use alone, see label for


Tanos (famoxadone +

Acrobat 50 WP
(Phosphorous acid)

Scala SC

Endura (boscalid)

Terraclor 75 WP

Fix Copper
+mancozeb or maneb

Kocide 101 or
Champion 77 WPs

(copper hydroxide)
Kocide 4.5 LF (copper M1
Kocide 2000 53.8 DF M1

(copper hydroxide)
Champ 57.6 DP
(copper hydroxide)
Basicop 53 WP
(copper sulfate)
Kocide 61.4
DF(copper hydroxide)
Cuprofix Disperss
36.9 DF(copper
Allpro Exotherm
(20 % chlorothalonil)

Reason 500SC

Ranman 400SC

Maximum Rate Min.
Fungicide Acre / Days to
Group1 Applic. Season Harvest


72 oz

6.4 oz 32 oz

2 qts. in a
of 100 gal.

7 fl oz 35 fl oz
0.27 Ibs 1.4 Ibs

3.5 oz 21


M1 /M3

See Label See Label

Pertinent Diseases
or Pathogens

3 Early blight
Late blight Target spot
Bacterial spot
4 Late blight

0 Phytophthora sp. (root
Pythium sp. (Damping-
1 Early blight

0 Target spot
Early Blight
(Alternaria solani)
Soil Southern blight
t. at (Sclerotium rolfsii)
5 Bacterial spot
Bacterial speck

See label for details

See label for details

Dosage given is for drip application.
See label for restrictions and details

Use only in a tank mix with another
effective fungicide
(non FRAC code 9), see label
Alternate with non-FRAC code 7
fungicides, see label

See label for application type and

Mancozeb or maneb enhances
bactericidal effect of Fix copper
compounds, see label

4 Ibs.

2 2/3 pts

1 1/3 Ibs

4 Ibs.

M5 1 can/
1000 sq.

5.5-8.2 oz 24.6 Ib


16 oz

7 Botrytis
Leaf mold
Late blight
Early blight Gray leaf
Target spot
14 Early blight
Late blight
Septoria leaf spot
0 Late Blight

Greenhouse use only. Allow can to
remain overnight and then ventilate.
Do not use when greenhouse
temperature is above 75 F, see label

See label for details

Limit is 6 appl./crop, see label


Maximum Rate Min.
Fungicide Acre / Days to

Pertinent Diseases

Chemical Group1 Applic. Season Harvest or Pathogens Remarks2
Serenade Biological See label See label 0 Bacterial spot mix with copper compounds, see
Serenade ASO material label
Serenade Max
(Bacillus subtilis)

(B. pumilis)

SFungicide group (FRAC code): Numbers (1-37) and letters (M, U, P) are used to distinguish the fungicide mode of action groups.
All fungicides within the same group (with same number or letter) indicate same active ingredient or similar mode of action. This
information must be considered for the fungicide resistance management decisions. M = Multi site inhibitors, fungicide resistance risk
is low; U = Recent molecules with unknown mode of action; P = host plant defense inducers. Source: http://www.frac.info/ (FRAC =
Fungicide Resistance Action Committee).
2 Information provided in this table applies only to Florida. Be sure to read a current product label before applying any chemical. The use
of brand names and any mention or listing of commercial products or services in the publication does not imply endorsement by the
University of Florida Cooperative Extension Service nor discrimination against similar products or services not mentioned.
3Tank mix of mancozeb or maneb enhances bactericidal effect of copper compounds.


Selected Insecticides Approved for Use on
Insects Attacking Tomatoes

Susan Webb
UF/IFAS Entomology and Nematology
Dept., Gainesville


Trade Name
(Common Name)
Admire 2F

Admire Pro
Admire 2F

Admire Pro

Admire 2F
Admire Pro

Agree WG
(Bacillus thuringiensis
subspecies aizawai)

*Agri-Mek 0.15EC

*Ambush 25W

0.75-1.0 Ib

16-24 fl oz

7-10.5 fl oz
1.4 fl oz/1000

0.6 fl oz/1000
0.1 fl oz/1000
0.44 fl
0.5-2.0 Ib

8-16 fl oz

3.2-12.8 oz




Days to

Insects C
twospotted spider

21 aphids, Colorado
potato beetle,
flea beetles,
thrips (foliar
feeding thrips
only), whiteflies

0 (soil) aphids, whiteflies

21 aphids, whiteflies

0 lepidopteran
larvae (caterpillar

12 7 Colorado potato
beetle, Liriomyza
leafminers, spider
mite, tomato
tomato russet
12 up to day of beet armyworm,
harvest cabbage looper,
Colorado potato
beetle, granulate
tomato pinworm,



2 One application per
4A Most effective if
applied to soil at
transplanting. Limited
to 24 oz/acre. Admire
Pro limited to 10.5 fl

4A Greenhouse Use: 1
application to mature
plants, see label for

4A Planthouse: 1
application. See label.

11B1 Apply when larvae
are small for best
control. Can be used
in greenhouse. OMRI-
6 Do not make more
than 2 sequential
applications. Do not
apply more than 48 fl
oz per acre per season.

3 Do not use on cherry
tomatoes. Do not
apply more than
1.2 Ib ai/acre per
season (76.8 oz). Not
recommended for
control of vegetable
leafminer in Florida.


Trade Name
(Common Name)
*Asana XL (0.66EC)

Assail 70WP

Assail 30 SG


Azatin XL

2.9-9.6 fl oz


0.6-1.7 oz

1.5-4.0 oz
2.5-3.5 oz

1-2 pts, up
to 3.5 pts, if

5-21 fl oz

Days to

beet armyworm
(aids in control),
cabbage looper,
Colorado potato
beetle, cutworms,
flea beetles,
potato aphid,
tomato pinworm,

7 aphids, Colorado
potato beetle,
thrips, whiteflies

3 beet armyworm,
loopers, southern
tomato pinworm,
suppression of
0 aphids, beetles,
mites, stink bugs,
thrips, weevils,
0 aphids, beetles,
thrips, weevils,


Not recommended for
control of vegetable
leafminer in Florida.
Do not apply more
than 0.5 Ib ai per acre
per season, or 10
applications at highest

4A Do not apply to
crop that has been
already treated
with imidacloprid
or thiamethoxam
at planting. Begin
applications for
whiteflies when first
adults are noticed. Do
not apply more than
4 times per season or
apply more often than
every 7 days.

22 Do not apply more
than 14 ounces of
product per acre per
crop. Minimum spray
interval is 5 days.

26 Antifeedant, repellant,
insect growth
regulator. OMRI-

26 Antifeedant, repellant,
insect growth


Trade Name
(Common Name)
*Baythroid 2

Biobit HP
(Bacillus thuringiensis
subspecies kurstaki)

BotaniGard 22 WP, ES
(Beauveria bassiana)

*Capture 2EC

CheckMate TPW,

Confirm 2F

1.6-2.8 fl oz

0.5-2.0 Ib

0.5-2 lb/100 gal
0.5-2 qts 100/

2.1-5.2 fl oz





200 dispenser
1.2-6.0 fl oz
6-16 fl oz

Days to

beet armyworm('),
cabbage looper,
Colorado potato
beetle, dipterous
corn borer,
flea beetles,
potato aphid,
stink bugs,
tomato pinworm,

cutworm ,
western flower
thrips, whitefly(2)
0 caterpillars (will
not control large

0 aphids, thrips,

1 aphids,
corn earworm,
flea beetles,
mites, stink bug
spp., tarnished
plant bug, thrips,
0 tomato pinworm

7 armyworms,
black cutworm,


(1) Ist and 2nd instars

(2) suppression
Do not apply more
than 0.26 Ib ai per acre
per season.

Maximum number of
applications: 6.

11B2 Treat when larvae
are young. Good
coverage is essential.
Can be used in the
May be used in
Contact dealer for
recommendations if an
adjuvant must be used.
Not compatible in tank
mix with fungicides.
3 Make no more than
4 applications per
season. Do not make
applications less than
10 days apart.

For mating disruption -
See label. TPW
formulation. OMRI-
18 Product is a slow-
acting IGR that will not
kill larvae immediately.
Do not apply more
than 1.0 Ib ai per acre
per season.


Trade Name
(Common Name)
Courier 70WP, 40SC

Crymax WDG
(Bacillus thuringiensis
subspecies kurstaki)
*Danitol 2.4 EC

(Bacillus thuringiensis
subspecies kurstaki)
*Diazinon AG500; 4E;
*50 W

Dimethoate 4 EC, 2.67 EC

DiPel DF
(Bacillus thuringiensis
supspecies kurstakl)

6-9 oz
9-13.6 fl oz

0.5-2.0 Ib

10.67 fl oz



Days to

whitefly nymphs

0 caterpillars

24 3 days, or 7
if mixed with
Monitor 4

0.25-1.5 Ib

AG500, 4E:
0.5-1.5 pts
0.5-1.5 Ib

beet armyworm,
cabbage looper,
potato aphid,
silverleaf whitefly,
stink bugs, thrips,
tomato pinworm,
spider mites,

0 caterpillars

1 aphids, beet
cucumber beetle,
Drosophila, fall
preplant cutworms,
mole crickets,
7 aphids,

0 caterpillars

AG500, 4E:
1-4 qts
50W: 2-8 Ib
0.5-1.0 pt
0.75-1.5 pt
0.5-2.0 Ib


See label for plantback
restrictions. Apply
when a threshold is
reached of 5 nymphs
per 10 leaflets from
the middle of the
plant. Product is a
slow-acting IGR that
will not kill nymphs
immediately. No more
than 2 applications
per season. Allow at
least 28 days between

11B2 Use high rate for
armyworms. Treat
when larvae are young.
3 Use alone for control
of fruitworms, stink
bugs, twospotted
spider mites, and
armyworms. Tank-mix
with Monitor 4 for
all others, especially
whitefly. Do not apply
more than 0.8 Ib ai
per acre per season.
Do not tank mix with
11B2 Use higher rates for
armyworms. OMRI-
1B Will not control
resistant leafminers.
Do not apply more
than five times per

1B Will not control
resistant leafminers.

11 B2 Treat when larvae are
young. Good coverage
is essential. OMRI-


Trade Name
(Common Name)
Endosulfan 3EC


Esteem Ant Bait


Intrepid 2F

Javelin WG
(Bacillus thuringiensis
subspecies kurstaki)

0.66-1.33 qt

0.5-2.5 oz

1.5-2.0 Ib

1.0-1.5 Ib

2.75 oz






4-16 fl oz

Days to

Insects C
aphids, blister
beetle, cabbage
looper, Colorado
potato beetle,
flea beetles,
hornworms, stink
bugs, tomato

tomato russet
mite, whiteflies,
1 armyworms,
potato beetle,
flower thrips,
loopers, other
tomato pinworm
1 red imported fire
0 fire ants

0 if 2
14 if 3 or 4

green peach
aphid, potato
suppression of

1 beet armyworm,
cabbage looper,
fall armyworm,
fruitworm, true
0 most caterpillars,
but not

0.12-1.5 Ib



2 Do not exceed a
maximum of 3.0 Ib
active ingredient per
acre per year or apply
more than 6 times. Can
be used in greenhouse.

5 Do not apply more
than 9 oz per acre per

7D Apply when ants are
actively foraging.
7A Slow-acting IGR
(insect growth
regulator). Best applied
early spring and fall
where crop will be
grown. Colonies will
be reduced after three
weeks and eliminated
after 8 to 10 weeks.
May be applied by
ground equipment or
9B Do not make more
than four applications.
24(c) label for growing
transplants also.

18 Do not apply more
than 64 fl oz acre per
Product is a slow-
acting IGR that will not
kill larvae immediately.

11B2 Treat when larvae
are young. Thorough
coverage is essential.


Trade Name
(Common Name)
Kelthane MF 4

Knack IGR


*Lannate LV, *SP

Lepinox WDG
(Bacillus thuringiensis
subspecies kurstaki)

Malathion 8 F
*Monitor 4EC

0.75-1.5 pt

8-10 fl oz

8-16 Ib

0.75-3.0 pt
0.25-1.0 Ib





1.0-2.0 Ib

1.5-2 pt

1.5-2 pts

[24(c) labels]

M-Pede 49% EC
(Soap, insecticidal)

1-2% V/V

Days to

tomato russet
mites, twospotted
and other
spider mites

14 immature

14 blister beetle,
cabbage looper,
Colorado potato
beetle larvae,
flea beetles,
tomato pinworm
1 aphids,
beet armyworm,
fall armyworm,
loopers, southern
tomato pinworm,
0 for most
including beet
armyworm (see
1 aphids,
Drosophila, mites
7 aphids,
pinworm '(),

0 aphids,
mites, plant bugs,
thrips, whiteflies


Do not apply more
than twice a season or
more than 1.6 pts per

7D Apply when a threshold
is reached of 5 nymphs
per 10 leaflets from
the middle of the
plant. Product is a
slow-acting IGR that
will not kill nymphs
immediately. Make
no more than two
applications per
9A Minimum of 7 days
between applications.
Do not apply more
than 64 Ibs per acre
per season. Not for
cherry tomatoes.

1A Do not apply more
than 6.3 Ib ai/acre per

11B2 Treat when larvae
are small. Thorough
coverage is essential.

1B Can be used in
1B (1) Suppression only
(2) Use as tank mix
with a pyrethroid for
whitefly control.
Do not apply more
than 8 pts per acre
per crop season,
nor within 7 days of


Trade Name
(Common Name)
*Mustang Max

Neemix 4.5

Oberon 2SC


2.24-4.0 oz


4-16 fl oz

7.0-8.5 fl oz

5-8 fl oz

Days to

Insects Code1
beet armyworm, 3
cabbage looper,
Colorado potato
beetle, cutworms,
fall armyworm,
flea beetles,
green and brown
stink bugs,
Lygus bugs, plant
bugs, southern
budworm, tomato
tomato pinworm,
true armyworm,
armyworm. Aides
in control of
aphids, thrips and

0 aphids,
psyllids, Colorado
potato beetle,
loopers, tomato
fruitworm (corn
tomato pinworm,
0 tomato pinworm

7 broad mite,
twospotted spider
mite, whiteflies
(eggs and
30 aphids, Colorado
potato beetles,
flea beetles,

Not recommended for
vegetable leafminer in
Florida. Do not make
applications less than
7 days apart. Do not
apply more than 0.3 Ib
ai per acre per season.

18A IGR, feeding repellant.

For mating disruption -
See label.
23 Maximum amount
per crop: 25.5 fl oz/
acre. No more than 3

4A Soil application. See
label for rotational


Trade Name
(Common Name)
*Pounce 3.2 EC

*Proaxis Insecticide

(emamectin benzoate)

Prokil Cryolite 96

2-8 oz

1.92-3.84 fl oz

2.4-4.8 oz

10-16 Ib





Days to

beet armyworm,
cabbage looper,
Colorado potato
beetle, dipterous

tomato pinworm
5 aphids(1), beet
blister beetles,
cabbage looper,
Colorado potato
beetle, cucumber
beetles (adults),
hornworms, fall
flea beetles,
leafhoppers, plant
bugs, southern
spider mites('),
stink bugs,
thrips0l), tobacco
budworm, tomato
tomato pinworm,
weevil (adult),
7 beet armyworm,
cabbage looper,
fall armyworm,
budworm, tomato
tomato pinworm,
14 blister beetle,
cabbage looper,
Colorado potato
beetle larvae,
flea beetles,


Do not apply to cherry
or grape tomatoes
(fruit less than 1 inch
in diameter). Do not
apply more than 1.2 Ib
ai per acre per season.

3 (1) Suppression only.
(2) First and second
instars only.

Do not apply more
than 2.88 pints per
acre per season.

6 No more than 28.8
oz/acre per season.

9A Minimum of 7 days
between applications.
Do not apply more
than 64 Ibs per acre
per season. Not for
cherry tomatoes.


Trade Name
(Common Name)
Provado 1.6F (imidacloprid)

Pyrellin EC
(pyrethrin + rotenone)

Sevin 80S; XLR; 4F

SpinTor 2SC (spinosad)

Sulfur (many brands)

*Telone C-35
(dichloropropene +

*Telone II


3.8 oz

1-2 pt

80S: 0.63-2.5
XLR; 4F: 0.5-
2.0 A

1.5-8.0 fl oz

See label

See label 5 days (See

Days to

Insects Code1
aphids, Colorado 4A
potato beetle,

12 12 hours aphids, Colorado
potato beetle,
beetles, flea
beetles, flea
loopers, mites,
plant bugs, stink
bugs, thrips,
vegetable weevil,
12 3 Colorado potato
beetle, cutworms,
fall armyworm,
flea beetles,
lace bugs,
plant bugs,
stink bugs(),
thrips(), tomato
tomato pinworm,
4 1 armyworms,
potato beetle,
flower thrips,
loopers, Thrips
palmi, tomato
tomato pinworm

24 see label tomato russet

preplant garden

Do not apply to
crop that has been
already treated with
imidacloprid or
thiamethoxam at
planting. Do not apply
more than 18.75 oz per
acre as foliar spray.

3, 21

1A (1) suppression

Do not apply more
than seven times. Do
not apply a total of
more than 10 Ib or 8 qt
per acre per crop.

5 Do not apply to
seedlings grown for
transplant within
a greenhouse or
shadehouse. Leafminer
and thrips control may
be improved by adding
an adjuvant. Do not
apply more than three
times in any 21 day
period. Do not apply
more than 29 ozs per
acre per crop.

See supplemental
label for restrictions
in certain Florida


Trade Name
(Common Name)

(extract of neem oil)

Ultra Fine Oil,
JMS Stylet-Oil, and others
(oil, insecticidal)


*Vydate L 2EC


26.6 oz

0.5-2.0% VN

3-6 qts/100 gal

foliar: 1-4 oz

soil: 5-6 oz

foliar: 2-4 pt

1.92-3.84 fl oz


Days to

potato beetle
(suppression of),

0 aphids, mites,
of thrips and

0 aphids,
beetle larvae,
leafminers, mites,
thrips, whiteflies,
viruses (JMS)
foliar: 1 Colorado potato
soil: 21 beetle, green
peach aphid,
flea beetles,
potato aphid
thrips, whiteflies
3 aphids, Colorado
potato beetle,
(except Liriomyza
trifolii), whiteflies
5 aphids(), beet
cabbage looper,
Colorado potato
beetle, cutworms,
fall armyworm(2),
flea beetles,
plant bugs,
stink bugs,
thrips(3), tomato
tomato pinworm,


No more than 6
applications per crop.

26 Apply morning or
evening to reduce
potential for leaf burn.
Toxic to bees exposed
to direct treatment.
Do not exceed four
applications per
season. Organic Stylet-
Oil is

4A Use only one
application method
(soil or foliar). Limited
to three applications
per season. Do not use
on grape or cherry

1A Do not apply more
than 32 pts per acre
per season.

3 (1) suppression only
(2) for control of 1st
and 2nd instars only.
Do not apply more
than 0.36 Ib ai per acre
per season.
(3)Does not control
western flower thrips.


Trade Name Rate REI Days to MOA
(Common Name) (product/acre) (hours) Harvest Insects Code1 Notes
Xentari DF 0.5-2 Ib 4 0 caterpillars 11B1 Treat when larvae
(Bacillus thuringiensis are young. Thorough
subspecies aizawai) coverage is essential.
May be used in the
greenhouse. Can
be used in organic
production. OMRI-
The pesticide information presented in this table was current with federal and state regulations at the time of revision. The user
is responsible for determining the intended use is consistent with the label of the product being used. Use pesticides safely. Read
and follow label instructions.

SMode of Action codes for vegetable pest insecticides from the Insecticide Resistance Action Committee (IRAC) Mode of Action
Classification v.3.3 October 2003. 1A. Acetylcholine esterase inhibitors, Carbamates 1B. Acetylcholine esterase
inhibitors, Organophosphates
2A. GABA-gated chloride channel antagonists
3. Sodium channel modulators
4A. Nicotinic Acetylcholine receptor agonists/antagonists, Neonicotinoids
5. Nicotinic Acetylcholine receptor agonists (not group 4)
6. Chloride channel activators
7A. Juvenile hormone mimics, Juvenile hormone analogues
7D. Juvenile hormone mimics, Pyriproxifen
9A. Compounds of unknown or non-specific mode of action (selective feeding blockers), Cryolite
9B. Compounds of unknown or non-specific mode of action (selective feeding blockers), Pymetrozine
11B1. Microbial disruptors of insect midgut membranes, B.t. var aizawai
11B2. Microbial disruptors of insect midgut membranes, B.t. var kurstaki
12B. Inhibitors of oxidative phosphorylation, disruptors of ATP formation, Organotin miticide
15. Inhibitors of chitin biosynthesis, type 0, Lepidopteran
16. Inhibitors of chitin biosynthesis, type 1, Homopteran
17. Inhibitors of chitin biosynthesis, type 2, Dipteran
18. Ecdysone agonist/disruptor
20. Site II electron transport inhibitors
21. Site I electron transport inhibitors
22. Voltage-dependent sodium channel blocker
23. Inhibitors of lipid biosynthesis
25. Neuroactive (unknown mode of action)
26. Unknown mode of action, Azadirachtin
2 OMRI listed: Listed by the Organic Materials Review Institute for use in organic production.
* Restricted Use Only


Weed Control in Tomato

William M. Stall and James P. Gilreath
UF/IFAS Horticultural Sciences Department, Gainesville


Although weed control has always been an important
component of tomato production, its importance has increased
with the introduction of the sweet potato whitefly and development
of the associated irregular ripening problem. Increased incidence
of several viral disorders of tomatoes also reinforces the need
for good weed control. Common weeds, such as the difficult to
control nightshade, and volunteer tomatoes (considered a weed
in this context) are hosts to many tomato pests, including sweet
potato whitefly, bacterial spot, and viruses. Control of these pests
is often tied, at least in part, to control of weed hosts. Most growers
concentrate on weed control in row middles; however, peripheral
areas of the farm may be neglected. Weed hosts and pests may
flourish in these areas and serve as reservoirs for re-infestation
of tomatoes by various pests. Thus, it is important for growers to
think in terms of weed management on all of the farm, not just the
actual crop area.
Total farm weed management is more complex than row
middle weed control because several different sites, and possible
herbicide label restrictions are involved. Often weed species in
row middles differ from those on the rest of the farm, and this
might dictate different approaches. Sites other than row middles
include roadways, fallow fields, equipment parking areas, well
and pump areas, fence rows and associated perimeter areas, and
Disking is probably the least expensive weed control
procedure for fallow fields. Where weed growth is mostly grasses,
clean cultivation is not as important as in fields infested with
nightshade and other disease and insect hosts. In the latter situation,
weed growth should be kept to a minimum throughout the year. If
cover crops are planted, they should be plants which do not serve
as hosts for tomato diseases and insects. Some perimeter areas are
easily disked, but berms and field ditches are not and some form
of chemical weed control may have to be used on these areas.
We are not advocating bare ground on the farm as this can lead
to other serious problems, such as soil erosion and sand blasting
of plants; however, where undesirable plants exist, some control
should be practiced, if practical, and replacement of undesirable
species with less troublesome ones, such as bahiagrass, might be
Certainly fence rows and areas around buildings and pumps
should be kept weed-free, if for no other reason than safety.
Herbicides can be applied in these situations, provided care is
exercised to keep it from drifting onto the tomato crop.
Field ditches as well as canals are a special consideration
because many herbicides are not labeled for use on aquatic
sites. Where herbicidal spray may contact water and be in close
proximity to tomato plants, for all practical purposes, growers
probably would be wise to use Diquat only. On canals where drift
onto the crop is not a problem and weeds are more woody, Rodeo,
a systemic herbicide, could be used. Other herbicide possibilities

exist, as listed in Table 1. Growers are cautioned against using
Arsenal on tomato farms as tomatoes are very sensitive to this
herbicide. Particular caution should be exercised ifArsenal is used
on seepage irrigated farms as it has been observed to move in
some situations.
Use of rye as a windbreak has become a common practice in
the spring; however, in some cases, adverse effects have resulted.
If undesirable insects such as thrips buildup on the rye, contact
herbicide can be applied to kill it and eliminate it as a host, yet the
remaining stubble could continue serving as a windbreak.
The greatest row middle weed control problem confronting
the tomato industry today is control of nightshade. Nightshade
has developed varying levels of resistance to some post-emergent
herbicides in different areas of the state. Best control with
post-emergence (directed) contact herbicides are obtained when
the nightshade is 4 to 6 inches tall, rapidly growing and not
stressed. Two applications in about 50 gallons per acre using a
good surfactant are usually necessary.
With post-directed contact herbicides, several studies have
shown that gallonage above 60 gallons per acre will actually dilute
the herbicides and therefore reduce efficacy. Good leaf coverage
can be obtained with volumes of 50 gallons or less per acre. A
good surfactant can do more to improve the wetting capability
of a spray than can increasing the water volume. Many adjuvants
are available commercially. Some adjuvants contain more active
ingredient then others and herbicide labels may specify a minimum
active ingredient rate for the adjuvant in the spray mix. Before
selecting an adjuvant, refer to the herbicide label to determine the
adjuvant specifications.

Postharvest Vine Desiccation. Additionally important
is good field sanitation with regard to crop residue. Rapid and
thorough destruction of tomato vines at the end of the season
always has been promoted; however, this practice takes on
new importance with the sweet potato whitefly. Good canopy
penetration of pesticidal sprays is difficult with conventional
hydraulic sprayers once the tomato plant develops a vigorous
bush due to foliar interception of spray droplets. The sweet potato
whitefly population on commercial farms was observed to begin
a dramatic, rapid increase about the time of first harvest in the
spring of 1989. This increase appears to continue until tomato
vines are killed. It is believed this increase is due, in part, to
coverage and penetration. Thus, it would be wise for growers to
continue spraying for whiteflies until the crop is destroyed and
to destroy the crop as soon as possible with the fastest means
available. Gramoxone Inteon is now labeled for postharvest
dessication of tomato vines. The label differs slightly from the
previous Gramoxone labels, so it's important to read and follow
the label directions.
The importance of rapid vine destruction can not be
overstressed. Merely turning off the irrigation and allowing the
crop to die is not sufficient; application ofa desiccant followed by
burning is the prudent course.


Table 1. Chemical weed controls: tomatoes.
Rate (Ibs. AI./Acre)
Herbicide Labeled Crops Time of Application to Crop Mineral Muck
Carfentrazone Tomato Preplant 0.031 0.031
(Aim) Directed-Hooded row-middles
Remarks: Aim may be applied as a preplant burndown treatment and /or as a post-directed hooded application to row middles for the
burndown of emerged broadleaf weeds. May be tank mixed with other registered herbicides. May be applied up to 2 oz (0.031 Ib ai).
Use a quality spray adjuvant such as crop oil concentrate (coc) or non-ionic surfactant at recommended rates.
Clethodim Tomatoes Postemergence 0.9-.125 ---
(Select 2 EC)
Remarks: Postemergence control of actively growing annual grasses. Apply at 6-8 fl oz/acre. Use high rate under heavy grass
pressure and/or when grasses are at maximum height. Always use a crop oil concentrate at 1% v/v in the finished spray volume. Do
not apply within 20 days of tomato harvest.
DCPA Established Tomatoes Posttransplanting after crop 6.0-8.0 ---
(Dacthal W-75) establishment (non-mulched)
Remarks: Controls germinating annuals. Apply to weed-free soil 6 to 8 weeks after crop is established and growing rapidly or to
moist soil in row middles after crop establishment. Note label precautions of replanting non-registered crops within 8 months.
Glyphosate Tomato Chemical fallow Preplant, pre- 0.3-1.0 ---
(Roundup, Durango Touchdown, emergence, Pre transplant

Remarks: Roundup, Glyphomax and touchdown have several formulations. Check the label of each for specific labeling directions.
Halosulfuron Tomatoes Pre-transplant 0.024- 0.036 ---
(Sandea) Postemergtence
Row middles
Remarks: A total of 2 applications of Sandea may be applied as either one pre-transplant soil surface treatment at 0.5-0.75 oz.
product; one over-the-top application 14 days after transplanting at 0.5-0.75 oz. product; and/or postemergence applications(s) of
up to 1 oz. product (0.047 Ib ai) to row middles. A 30-day PHI will be observed. For postemergence and row middle applications, a
surfactant should be added to the spray mix.
S-Metolachlor Tomatoes Pretransplant 1.0-1.3 ---
(Dual Magnum) Row middles
Remarks: Apply Dual Magnum preplant non-incorporated to the top of a pressed bed as the last step prior to laying plastic. May also
be used to treat row-middles. Label rates are 1.0-1.33 pts/A if organic matter is less than 3%. Research has shown that the 1.33 pt
may be too high in some Florida soils except in row middles. Good results have been seen at 0.6 pts to 1.0 pints especially in tank
mix situations under mulch. Use on a trial basis.
Metribuzin Tomatoes Postemergence 0.25 0.5 ---
(Sencor DF) (Sencor 4) Posttransplanting after
Remarks: Controls small emerged weeds after transplants are established direct-seeded plants reach 5 to 6 true leaf stage. Apply in
single or multiple applications with a minimum of 14 days between treatments and a maximum of 1.0 Ib ai/acre within a crop season.
Avoid applications for 3 days following cool, wet or cloudy weather to reduce possible crop injury.
Metribuzin Tomatoes Directed spray in row middles 0.25 1.0 ---
(Sencor DF) (Sencor 4)
Remarks: Apply in single or multiple applications with a minimum of 14 days between treatments and maximum of 1.0 Ib ai/acre
within crop season. Avoid applications for 3 days following cool, wet or cloudy weather to reduce possible crop injury. Label states
control of many annual grasses and broadleaf weeds including, lambsquarter, fall panicum, amaranthus sp., Florida pusley, common
ragweed, sicklepod, and spotted spurge.
Napropamid Tomatoes Preplant incorporated 1.0 2.0 ---
(Devrinol 50DF)
Remarks: Apply to well worked soil that is dry enough to permit thorough incorporation to a depth of 1 to 2 inches. Incorporate same
day as applied. For direct-seeded or transplanted tomatoes.
Napropamid Tomatoes Surface treatment 2.0 ---
(Devrinol 50DF)
Remarks: Controls germinating annuals. Apply to bed tops after bedding but before plastic application. Rainfall or overhead-irrigate
sufficient to wet soil 1 inch in depth should follow treatment within 24 hours. May be applied to row middles between mulched beds.
A special Local Needs 24(c) Label for Florida. Label states control of weeds including Texas panicum, pigweed, purslane, Florida
pusley, and signalgrass.


Table 1. Chemical weed controls: tomatoes.
Rate (Ibs. AI./Acre)
Herbicide Labeled Crops Time of Application to Crop Mineral Muck
Oxyfluorfen Tomatoes Fallow bed 0.25 0.5
(Goal 2XL) (Goaltender)
Remarks: Must have a 30 day treatment-planting interval for transplanted tomatoes. Apply as a preemergence broadcast or banded
treatment at 1-2 pt/A or 2 to 1 pt/A for Goaltender to preformed beds. Mulch may be applied any time during the 30-day interval.
Paraquat Tomatoes Premergence; Pretransplant 0.62 0.94 ---
(Gramoxone Inteon)
Remarks: Controls emerged weeds. Use a non-ionic spreader and thoroughly wet weed foliage.
Paraquat Tomatoes Post directed spray in row middle 0.47 ---
(Gramoxone Inteon)
Remarks: Controls emerged weeds. Direct spray over emerged weeds 1 to 6 inches tall in row middles between mulched beds. Use a
non-ionic spreader. Use low pressure and shields to control drift. Do not apply more than 3 times per season.
Paraquat Tomato Postharvest 0.62-0.93 0.46-0.62
(Gramoxone Inteon) dessication
Remarks: Broadcast spry over the top of plants after last harvest. Label for Boa states use of 1.5-2.0 pts while Gramoxone label is
from 2-3 pts. Use a nonionic surfactant at 1 pt/100 gals to 1 qt/100 gals spray solution. Thorough coverage is required to ensure
maximum herbicide burndown. Do not use treated crop for human or animal consumption.
Pelargonic Acid (Scythe) Fruiting Vegetable (tomato) PreplantPreemergence 3-10% v/v
Remarks: Product is a contact, nonselective, foliar applied herbicide. There is no residual control. May be tank mixed with several soil
residual compounds. Consult the label for rates. Has a greenhouse and growth structure label.
Rimsulfuron Tomato Posttransplant and directed-row middles 0.25 0.5 oz.
Remarks: Matrix may be applied preemergence (seeded), postemergence, posttransplant and applied directed to row middles. May
be applied at 1-2 oz. product (0.25-0.5 oz ai) in single or sequential applications. A maximum of 4 oz. product per acre per year may
be applied. For post (weed) applications, use a non-ionic surfactant at a rate of 0.25% v/v. for preemergence (weed) control, Matrix
must be activated in the soil with sprinkler irrigation or rainfall. Check crop rotational guidelines on label.
Sethoxydim (Poast) Tomatoes Postemergence 0.188 0.28
Remarks: Controls actively growing grass weeds. A total of 42 pts. product per acre may be applied in one season. Do not apply
within 20 days of harvest. Apply in 5 to 20 gallons of water adding 2 pts. of oil concentrate per acre. Unsatisfactory results may
occur if applied to grasses under stress. Use 0.188 Ib ai (1 pt.) to seedling grasses and up to 0.28 Ib ai (12 pts.) to perennial grasses
emerging from rhizomes etc. Consult label for grass species and growth stage for best control.
Trifloxysulfuron Tomatoes Post directed 0.007-0.014
(Envoke) (transplanted)
Remarks: Envoke can be applied at 0.1 to 0.2 oz product/A post-directed to transplanted tomatoes for control of nutsedge,
morningglory, pigweeds and other weeds listed on the label. Applications should be made prior to fruit set and at least45 days prior
to harvest. A non-ionic surfactant should be added to the spray mix.
Trifluralin Tomatoes Pretransplant incorporated 0.5
(Treflan HFP) (except Dade County)
(Treflan TR-10)
(Trifluralin 4EC)
Remarks: Controls germinating annuals. Incorporate 4 inches or less within 8 hours of application. Results in Florida are erratic on
soils with low organic matter and clay contents. Note label precautions of planting non-registered crops within 5 months. Do not
apply after transplanting.


Nematicides Registered for Use on
Florida Tomato

Joseph W. Noling
Extension Nematology, UF/IFAS,
Citrus Research & Education Center. Lake Alfred

jnolingufl. edu

Row Application (6' row spacing 36" bed)4
Broadcast Recommended Chisels Rate/1000
Product (Rate) Chisel Spacing (per Row) Rate/Acre Ft/Chisel
Methyl Bromide3 67-33 225-375 Ib 12" 3 112-187 Ib 5.1-8.6 Ib
Chloropicrin1 300-500 Ib 12" 3 150-250 Ib 6.9-11.5 Ib
Telone 112 9-12 gal 12" 3 4.5-9.0 gal 26-53 fl oz
Telone C-17 10.8-17.1 gal 12" 3 5.4-8.5 gal 31.8-50.2 fl oz
Telone C-35 13-20.5 gal 12" 3 6.5-13 gal 22-45.4 fl oz
Metham Sodium 50-75 gal 5" 6 25-37.5 gal 56-111 fl oz
Vydate L treat soil before or at planting with any other appropriate nematicide or a Vydate transplant water drench followed by Vydate
foliar sprays at 7-14 day intervals through the season; do not apply within 7 days of harvest; refer to directions in appropriate "state
labels", which must be in the hand of the user when applying pesticides under state registrations.

SIf treated area is tarped, dosage may be reduced by 33%.
2 The manufacturer of Telone II, Telone C-17, and Telone C-35 has restricted use only on soils that have a relatively shallow hard pan or
soil layer restrictive to downward water movement (such as a spodic horizon) within six feet of the ground surface and are capable of
supporting seepage irrigation regardless of irrigation method employed. Crop use of Telone products do not apply to the Homestead,
Dade county production regions of south Florida. Higher label application rates are possible for fields with cyst-forming nematodes.
Consult manufacturers label for personal protective equipment and other use restrictions which might apply.
3 As a grandfather clause, it is still possible to continue to use methyl bromide on any previous labeled crop as long as the methyl
bromide used comes from existing supplies produced prior to January 1, 2005. A critical use exemption (CUE) for continuing use of
methyl bromide for tomato, pepper, eggplant and strawberry has been awarded for calendar years 2005, 2006, 2007. Specific, certified
uses and labeling requirements for CUE acquired methyl bromide must be satisfied prior to grower purchase and use in these crops.
4Rate/acre estimated for row treatments to help determine the approximate amounts of chemical needed per acre of field. If rows are
closer, more chemical will be needed per acre; if wider, less.
Rates are believed to be correct for products listed when applied to mineral soils. Higher rates may be required for muck (organic) soils.
Growers have the final responsibility to guarantee that each product is used in a manner consistent with the label. The information was
compiled by the author as of June 21, 2006 as a reference for the commercial Florida tomato grower. The mentioning of a chemical or
proprietary product in this publication does not constitute a written recommendation or an endorsement for its use by the University
of Florida, Institute of Food and Agricultural Sciences, and does not imply its approval to the exclusion of other products that may be
suitable. Products mentioned in this publication are subject to changing Environmental Protection Agency (EPA) rules, regulations,
and restrictions. Additional products may become available or approved for use.


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