2001-2002 Report ofTomato Research

Supported by theFlorida Tomato Committee

1022 McCarty Hall / PO Box 110200Gainesville, FL 32611-0200

Phone: (352) 392-1784 / Fax: (352) 392-4965E-mail: research@gnv.ifas.ufl.edu

WWW: http://research.ifas.ufl.edu

Equal Opportunity/Affirmative Action Institution

Office of the Dean for ResearchFlorida Agricultural Experiment Station

MEMORANDUM

TO: The Florida Tomato Committee

FROM: Mary L. Duryea, Assistant Dean for Research

SUBJECT: 2001-2002 Research Report

DATE: September 5, 2002

This report describes research in UF/IFAS/FAES that received support from the Florida Tomato Commit-

tee during the past year. The Florida Tomato Committee support combines with State and Federal re-

sources providing critical operating support that allows IFAS tomato scientists to have a strong research

program focused on the tomato industry of Florida.

This is an extremely important partnership between the Tomato Industry and IFAS scientists. We have

worked together to identify the questions and needs for the industry. Then, again together we have priori-

tized the research to be accomplished. This year’s work ranged from methyl bromide alternatives to

tomato breeding to post-harvest handling, lycopene recovery and finally, marketing issues. Many of the

results are immediately applicable by the industry.

We hope to continue in our quest for improving production methods and product quality. We are pleased

to have the Florida Tomato Committee as a partner in programmatic support for tomato research. On

behalf of the scientists involved in tomato research, we thank you and appreciate your support.

This report of research results is presented in electronic format. We hope you find the information in the

report useful to all facets of tomato production.

MLD:las

Page Title Investigators

Control of Fusarium Crown Rot, Rootknot Nematodes andNutsedge with Soil Fumigants and Herbicides in SouthwestFlorida

James P. GilreathJoseph W. NolingErin N. Rosskopf

1

Residual Effects of Fumigant Alternatives on Nutsedge,Rootknot Nematode, and Fusarium Wilt of Fall Tomato andDouble Crop Cucumber/Cover Crop Production

James P. GilreathJoseph W. NolingJohn P. JonesPhyllis R. Gilreath

48

Development and Evaluation of a Biologically-Based Systemand a Chemically-Based Alternative System to Methyl Bromidefor Tomato Production in Miami-Dade County

64Waldemar KlassenHerbert H. BryanRobert T. McMillanYuncong LiQ. R. WangA. Abdul-BakiM. CadalloZ. A. HandooD. Chitwood

Breeding Tomatoes for Florida69 John W. Scott

Breeding Tomatoes for Resistance to all Three Races of theBacterial Spot Pathogen

John W. ScottJeffrey B. Jones74

Selection of Tomato Lines for Commercial Markets that Exhibita Fruit/Floral Character within a Balanced Sugar, Acid andVolatile Profile

77 Elizabeth A. BaldwinJohn W. Scott

Mining Gold in Florida: Feasibility of Lycopene and Novel By-Products Recoveries from Cull Tomatoes via Post-HarvestManipulations, Dehydration and CO2 Super Critical Extraction

83Amy SimmoneBala RathinasabapathiStephen T. TalcottSteven A. SargentJeffrey K. BrechtMurat O. BalabanMaurice R. Marshall

Sanitation to Eliminate Hazardous Microorganisms fromTomato Fruit

Jerry A. BartzKeith R. SchneiderKelly FelkySteven A. Sargent

Competition in the Winter Fresh Tomato Market John J. VanSickle

INDEX

FLORIDA TOMATO COMMITTEE2001-2002 IFAS Research Reports

96

101

1

Control of Fusarium Crown Rot,Rootknot Nematodes and Nutsedgewith Soil Fumigants and Herbicides inSouthwest Florida

James P. Gilreath, Joseph W. Noling and Erin N.

Rosskopf

AbstractFunding from the Florida Tomato Commit-

tee was leveraged with funding from the USDA /

IR-4 methyl bromide alternatives program to

support two large field experiments with as many

as 24 different fumigant treatments in Immokalee

in the spring of 2002 and in Bradenton during the

fall of 2001. The Bradenton experiment targeted

nutsedge, nematodes and Fusarium wilt, race 3;

whereas, the Immokalee trial focused on Fusarium

crown rot on a commercial farm. Labeled fumi-

gants, as well as experimental ones, were evaluated

in these experiments. Telone C-35 applied broad-

cast with a herbicide followed by additional chlo-

ropicrin in the bed provided good control of most

pests as did Inline applied via drip irrigation tubing

with herbicide broadcast. Combining Basamid

with Telone C-35 was effective for some pests but

yields appeared to suffer somewhat. Application

of metam sodium (Vapam) or metam potassium

(K-Pam) to the bed top through 3 drip irrigation

lines provided good pest control and yield compa-

rable to or better than methyl bromide in both

studies. Fosthiazate was effective when combined

with chloropicrin and Tillam, but some questions

remain about proper application procedures with

fosthiazate as well as Plant Pro and AU 110, both

of which did not provide good pest control in this

study. Results with Multiguard suggest we need to

do conduct additional research on application

technique to improve efficacy. Iodomethane

requires the addition of chloropicrin to enhance

soilborne pest control. While good data were

obtained on Fusarium wilt control, data for

Fusarium crown rot were less definitive as the pest

pressure was not high enough due to the unseason-

able weather during the spring of 2002. Methyl

bromide provided no control of crown rot in the

Immokalee trial. Some treatments which ap-

peared favorable for at least partial control of

crown rot included Plant Pro 20EC, Fosthiazate

applied via drip irrigation with 200 lb/acre of

chloropicrin in the bed, 100 lb/acre of AU 110 and

600 lb/acre of Multiguard. While no solid solu-

tions for Fusarium crown rot have been derived

from this work, a foundation has been laid for

future work, provided funding continues and we

are able to leverage the support of the Florida

Tomato Committee with that of other organizations

or agencies, like the USDA / IR-4 program.

Soil fumigant research has been conducted

at the Gulf Coast Research and Education Center

for over 30 years under the leadership of several

different scientists. In 1991, prior to the an-

nounced phase out of methyl bromide, this re-

search was accelerated and the program began a

slow, but steady increase in size and scope to

encompass the major soilborne pests in one orga-

nized research program. Although many different

methyl bromide alternatives have been evaluated

by this research group as part of the program,

much of the more recent work has focused on the

most likely alternatives for the immediate future,

rather than diluting resources by continuing screen-

ing efforts for new compounds. In 2001, we were

asked to take over operation of the USDA / IR-4

Methyl Bromide Alternatives Program. This

provided us with funding opportunities which ,

when combined with funding from the Florida

Tomato Committee, allowed us to develop a more

aggressive research program in the area of poten-

tial new alternatives for the Florida tomato grower.

Initially, we were committed to conduct a fumigant

study in southwest Florida focusing on Fusarium

crown rot; however, the additional funding pro-

vided by the IR-4 program allowed us to look at

more alternatives than originally planned and to

expand the work to include a second study, thereby

“hedging our bets”.

Fusarium crown rot has become a major

soilborne pest in southwest Florida tomato fields,

whereas Fusarium wilt is more prevalent in the

west central production area. Fusarium crown rot

and Fusarium wilt are caused by different subspe-

cies of the same fungal pathogen Fusarium

oxysporum. Fusarium crown rot is favored by

cooler soil temperatures than Fusarium wilt and

2

symptoms of the two are quite different. The most

notable physical difference is the absence of the

brilliant yellowing associated with Fusarium wilt

on plants infested with Fusarium crown rot. In

spite of their differences in appearance and envi-

ronmental conditions necessary for disease devel-

opment, control of Fusarium crown rot and wilt is

reported to be similar. For example, increasing soil

pH above 6.5 and reduction in usage of ammonium

containing fertilizer can aid in management of both

diseases. Soil fumigation with methyl bromide /

chloropicrin mixtures can be effective against

Fusarium wilt, but some question its effectiveness

against Fusarium crown rot because crown rot

incidence has increased in spite of universal use of

methyl bromide. Fusarium oxysporum produces

chlamydospores which are thick-walled spores

capable of surviving in soil and plant debris for

many years. The thickness of the spore walls also

may provide some protection from soil fumigants,

especially if the fumigant rate is low or the product

dissipates too quickly after application.

Rootknot nematodes and nutsedge (both

yellow and purple) also are serious soilborne pests

in tomato production. While methyl bromide /

chloropicrin mixtures generally provide good

control of these pests, many alternatives do not.

The single greatest challenge for growers in gen-

eral is nutsedge control; however, the greatest crop

reduction comes from a combination of all three

pest groups (nutsedge, nematodes, and soilborne

disease). Research conducted during 2001 - 2002

attempted to focus on all three pests, but greater

emphasis was placed on Fusarium crown rot than

other pests. Since crown rot and Fusarium wilt are

closely related and are said to respond similarly to

many control measures, two trials were conducted.

One trial was conducted in the Immokalee area on

a commercial tomato farm where Fusarium crown

rot was reported to be a major problem. A similar

experiment was conducted at the Gulf Coast

Research and Education Center in Bradenton in an

area with an established population of nutsedge,

rootknot nematode and Fusarium wilt. Treatments

in each experiment were replicated 4 to 5 times

and plot size ranged from 50 to 100 ft. There were

16 treatments at Bradenton and 24 at Immokalee.

All fumigants and herbicides were applied with

commercial equipment. Alternatives evaluated

consisted of methyl bromide, methyl iodide,

Telone C-35, Telone II, metam sodium (Vapam),

metam potassium (K-Pam), chloropicrin, Plant Pro,

fosthiazate, Basamid, Enzone, AU 110, Inline, and

Multiguard. Many of these products were used in

combination to enhance performance or cover

weak areas in their efficacy spectrum. The experi-

ment at Bradenton was initiated in mid August of

2001 with planting in late September for a fall crop

while fumigants in the Immokalee trial were

applied the week before Christmas for a spring

crop which was planted in late January. Planting

was delayed in Bradenton due to excessive soil

moisture and the complexity of some of the treat-

ments. Many of the alternative treatments con-

sisted of three or more pesticides and each had

specific application procedures and waiting periods

to be accommodated which increased the time

required to complete treatment applicaiton.

Data were collected for control of nutsedge,

nematodes, Fusarium wilt and crown rot, and crop

response, including fruit production by size grade

at each trial location. Because of the large number

of treatments and the quantity of data collected,

results only will be discussed in general terms.

Bradenton experiment:The first experiment was conducted in the

fall of 2001 at the GCREC in Bradenton to get the

bugs out of conducting such large tests before

initiating a study in a commercial field in

Immokalee. At Bradenton, tomato plant vigor was

reduced by Plant Pro and Enzone (Table 1). Nut-

sedge control was best with methyl bromide,

iodomethane (methyl iodide, trade name Midas),

broadcast Telone C-35 with Treflan + Devrinol

followed by additional chloropicrin in the bed, 75

gallons of metam sodium per acre applied through

3 drip tubes on top of the 28 inch-wide bed top,

Tillam broadcast with fosthiazate (rototilled in the

bed or drip applied) and chloropicrin in the bed,

Basamid with Telone C-35, and Treflan followed

by Telone C-35 with biweekly applications of

Messenger (Table 3). Good Fusarium wilt control

was provided by all treatments, except

Iodomethane without chloropicrin, Plant Pro, and

Enzone (Table 4). Although rootknot nematodes

3

were present in the test area prior to initiation,

excessive water at the beginning of the season

reduced the population and it never recovered

enough to distinguish differences among treat-

ments for rootknot control (Tables 5 and 6). Con-

trol of stunt nematodes was good with methyl

bromide, Telone C-35, 75 gallons per acre of

metam sodium with or without chloropicrin,

fosthiazate with chloropicrin, and Basamid with

Telone C-35. Sting nematodes were present but

not in sufficient numbers to cause economic

damange. Interestingly, cyst nematodes generally

are not thought of as being present in tomato fields,

but they were detected in a number of plots in this

study. Documentation of their presence in tomato

in west central - southwest Florida is important

because it provides justification for higher rates of

Telone C-35 per label instructions for those grow-

ers who may wish to use it. Enzone was the only

product to have more root galling than methyl

bromide as a result of rootknot nematodes (Table

7).

Tomato fruit yields were obtained from two

harvests at Bradenton (Tables 8 and 9) and data

were combined to provide season total yield in

each size grade. Metam sodium (e.g. Vapam) at 75

gal/acre applied through 3 drip tubes was the only

alternative to produce more extra large (5 x 6) size

fruit in the first harvest than methyl bromide and

yield was greater than that obtained with

iodomethane alone, metam + Telone II, metam +

Plant Pro, fosthiazate incorporated into the bed

with a rototiller, Basamid + Telone C-35, Enzone,

or Telone C-35 + Messenger (Table 8). There

were no differences in production of extra large

fruit in the second harvest (Table 9). Differences

among treatments in season total production were

similar to those observed in each of the two har-

vests (Table 10). Total extra large (5 x 6) fruit

production was similar to methyl bromide with

many of the treatments; however, metam produced

more than iodomethane, broadcast Telone C-35

with chloropicrin in bed, Plant Pro, in bed

fosthiazate, Basamid + Telone C-35, Enzone or

Telone C-35 with Messenger. Minor differences

existed in production of large (6 x 6) and medium

(6 x 7) size fruit in each harvest and season total,

but most of the production and differences were in

the extra large category. There were few differ-

ences in total marketable yield at Bradenton and

those which produced fewer extra large fruit in the

individual harvests produced fewer when yields

were totaled. Overall, the most promising treat-

ments in the fall at Bradenton, based on all pests

and yield, were Telone C-35 broadcast with herbi-

cide and additional chloropicrin applied to the bed,

iodomethane (Midas) with chloropicrin, metam

sodium (e.g. Vapam) applied through 3 drip tubes

per bed, and Fosthiazate drip applied with chlo-

ropicrin in bed and Tillam herbicide.

Immokalee experiment:The spring trial in Immokalee contained

more experimental compounds than the fall experi-

ment in Bradenton. Vigor of tomato plants (visual

estimate of plant health and growth) was estimated

about 3 weeks after planting and again near first

harvest. Early vigor estimates indicated little

difference in tomato plant vigor with most treat-

ments when compared to methyl bromide; how-

ever, the highest two rates of AU 110 reduced plant

vigor, but only the highest rate was significantly

less vigorous than methyl bromide (Table 11). A

clear dose response relationship was observed with

this product - as the rate increased, plant vigor

declined. Since this was the first time we had

worked with this product, we were learning how to

apply it and have made some changes since then

which will be reflected in future work. Thus,

although we observed phytotoxicity with this

product, it may have been the result of application

procedure or insufficient waiting period after

application. There were no differences in plant

vigor among treatments later in the season.

As previously indicated, the test site in

Immokalee was selected for its historical problem

with Fusarium crown rot. Methyl bromide had no

effect on crown rot in this experiment (Table 12).

Fifteen percent of the tomato plants in the methyl

bromide plots were infested with crown rot; the

same incidence level as the nontreated control.

Few differences were observed among fumigants

in this study, partially because the infection level

was so low. Early in the season Fusarium crown

rot was observed on a few young plants, but the air

and soil temperatures rose quickly in the spring as

4

unseasonably warm weather occurred early and

persisted for much of the spring. Once the opti-

mum soil temperature for crown rot (70 degrees

Fahrenheit) was exceeded, pathogen growth

slowed and disease incidence ceased to increase.

Some treatments which appeared favorable for at

least partial control of crown rot included Plant Pro

20EC, Fosthiazate applied via drip irrigation with

200 lb/acre of chloropicrin in the bed, 100 lb/acre

of AU 110 and 600 lb/acre of Multiguard. While

the incidence of crown rot with AU 110 appeared

to increase with higher rates, part of that increase

may have been due to early season phytotoxicity as

the incidence of crown rot was determined by

counting the number of dead plants as well as

those with actual symptoms of crown rot, since

most plant mortality appeared to be associated with

crown rot.

The experimental site near Immokalee also

was purported to have a considerable population of

nutsedge, but it did not as a result of the grower’s

persistence with a program of fallow applications

of Roundup and/or Touchdown followed by

disking. There were very few weeds present in the

beds at this site. Row middles were heavily in-

fested with nightshade, but none were observed in

the beds. The only weed affected by methyl

bromide alternatives was goosegrass (Table 13).

The number of goosegrass plants per 100 ft of row

was the least in the nontreated control plot. Sig-

nificantly more goosegrass was present in beds

treated with iodomethane and the 150 lb rate of AU

110. This site had very few nematodes in the soil.

As a result, there were no significant differences

among treatments (Table 14). Tomato plant roots

were examined at the end of the season and no

rootknot nematode gall production was observed

with any treatment.

Tomatoes were harvested three times,

sorted into marketable and cull based on external

appearance factors as instructed by the grower and

the farm owner, then the marketable fruit were

separated into size grades using a portable grader

with size standards conforming to those established

by the industry. Production of extra large (5 x 6)

fruit was affected in the first harvest only (Table

15), while medium size fruit (6 x 7) were the only

size affected by treatment in the second and third

harvests (Tables 16 and 17). Season total produc-

tion of extra large fruit was reduced (compared to

methyl bromide) where soil was treated with

metam sodium + Telone II and the two highest

rates of AU 110; again, most likely as a result of

early phytotoxicity with AU 110 (Table 18). Pro-

duction of medium size fruit relative to methyl

bromide was higher with metam sodium + Plant

Pro 20EC, but none of the treatments affected total

marketable fruit production in this study.

Overall, several alternatives appear promis-

ing. Broadcast application of Telone C-35 contin-

ues to show good efficacy when combined with a

herbicide and followed by additional chloropicrin

in the bed. The performance of iodomethane was

not as good as expected, but results of this study

point out the importance of combining this fumi-

gant with chloropicrin to achieve disease control.

Metam (Vapam and K-Pam) demonstrated good

efficacy in these two experiments when applied at

the full label rate to the bed top through 2 or more

drip irrigation lines. The number of lines depends

upon the bed width. Beds wider than 24 inches

appear to require 3 lines on the bed top. In some

cases, the addition of chloropicrin to the bed seems

to improve metam performance. While metam

performance has been erratic in the past, the

percentage of success has increased in the past year

as results of our related studies on water and dye

movement in the soil have been integrated into our

research. Fosthiazate combined with chloropicrin

and a herbicide appeared to have some promise,

but more work is needed on the proper application

procedure for fosthiazate. Inline performed well

in combination with Treflan and Devrinol and

more research is planned with it. Plant Pro prod-

ucts did not perform that well in these experiments,

but there is a question as to what is the proper

application procedure for these materials. That

question will be researched further in a separate

study. AU 110 was shown to be very effective in

previous research by the senior author of this

report; however, the formulation has changed and

we are still working on the proper formulation as

well as the most effective delivery method for it.

By leveraging the funding from the Florida

Tomato Committee with that from the USDA / IR-

4 methyl bromide alternatives program we have

5

been able to expand our research program, both in

terms of production regions and pests, and we hope

to continue this work in the coming years so that

we can deliver to the tomato industry practical

options for soil fumigation and better control

measures for Fusarium wilt and Fusarium crown

rot in addition to nutsedge and nematodes.

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Residual Effects of Fumigant Alterna-tives on Nutsedge, Rootknot Nematode,and Fusarium Wilt of Fall Tomato andDouble Cropped Cucumber / CoverCrop Production Fall 2001 - Spring 2002

James P. Gilreath, Joseph W. Noling, John P.

Jones and Phyllis R. Gilreath

Abstract. Results of the first four years of a five year study

indicate that mixtures of Telone and chloropicrin

(Telone C-17 or C-35), combined with Tillam

herbicide, are as effective as mixtures of methyl

bromide with chloropicrin (67/33 formulation) for

control of nutsedge, rootknot and other nematodes,

and fusarium wilt (race 3) in tomato and double

cropped cucumber. Tomato and cucumber produc-

tion was similar with Telone C-17 and methyl

bromide. Soil solarization using clear plastic

mulch to heat the soil for 8 weeks was intermediate

in its efficacy; that is, it generally was better than

applying no fumigant but was not as effective as

methyl bromide or Telone C-17 plus Tillam.

Solarization appeared to favor rootknot nematode

development, but the increased incidence com-

pared to the nontreated control was due to a lack of

root system for the control plants due to crop loss

as a result of fusarium wilt. Resurgence of nema-

todes was a problem with all treatments, including

methyl bromide, and rootknot nematodes were

quite plentiful on double cropped cucumber as a

result. Thus far, the spring cropping systems have

not had that much of an effect on the fall tomato

crop with the exception that stubby root nematode

was reduced following millet as a spring cover

crop and there appeared to be a trend for double

cropped cucumbers to increase the rootknot nema-

tode population in fall tomato. Completion of the

next two years of this study should determine

whether or not there is any truth to the theory that

alternative fumigant efficacy will decline with time

as residual effects of previous methyl bromide use

diminish.

Since 1993 research has been conducted at

the Gulf Coast Research and Education Center to

identify alternatives to methyl bromide and their

strengths and weaknesses. Additionally, we have

strived to find ways to improve efficacy with

various alternatives, whether it be through im-

provements in application technology or selection

of combinations of materials to overcome inherent

weaknesses in one product. Recognizing the

potential impact of the impending loss of methyl

bromide as a soil fumigant and the concern that

growers have about the long term effects of adopt-

ing alternative practices, a multi-year study was

initiated in the fall of 1998 to determine the effi-

cacy of a chemical and a nonchemical alternative

for soilborne pest control in fall tomato and spring

cropping systems. This study has been funded by

the Florida Tomato Committee, the USDA - ARS,

FFVA and Dow AgroSciences and is the only study

of its kind in the world.

This long term study compares the current

chemical replacement for methyl bromide, Telone

C-17 (contains 17% chloropicrin as compared to

35% in Telone C-35, at the beginning of this study

in 1998 only C-17 was available), and the best

nonchemical alternative, soil solarization, to

methyl bromide for broadspectrum soilborne pest

control in fall tomato. It also examines the effects

of these fall-applied alternatives on spring double-

cropped cucumber and millet grown as a cover

crop. In addition to the effects of the alternatives

on spring cropping practices, the study also investi-

gates the residual effects of the spring cropping

practices (double cropped cucumber, millet and

weed fallow) on the soilborne pests and crop for

tomato the following fall. Telone C-17 (35 gal/

acre) in the bed has been combined with Tillam

herbicide (4 lb.a.i./acre) applied broadcast prior to

bed formation for the first two years. Beginning in

the third year (fall 2000), Devrinol (2 lb.a.i./acre)

was tank mixed with Tillam to improve pigweed

and crabgrass control. Soil solarization was

conducted by covering beds with clear plastic

mulch for 8 weeks then painting the mulch film

white prior to planting tomato. In the summer of

2000, the solarization treatment was modified by

broadcast incorporating Devrinol herbicide (2

lb.a.i./acre) prior to bed formation in an attempt to

improve overall weed control. Methyl bromide /

chloropicrin mixture (67/33 @ 350 lb/acre) was

applied to the bed in the same fashion as Telone C-

49

17 using 3 chisels per bed. A nontreated control

was included to allow monitoring of pest popula-

tions and determination of actual control of indi-

vidual soilborne pests. This study is now begin-

ning its fifth year.

The study was designed to answer many

questions but the most important probably was

what happens over time when we continually use

these alternatives and the effect of previous methyl

bromide use is diminished. Over the first four

years of fumigation for fall tomato followed by

spring double cropping, millet cover crop or fallow

practices we have seen large fluctuations in nut-

sedge and nematode populations but a more stable

incidence level of Fusarium wilt, race 3, which has

averaged about 95% in the nontreated controls

since the second year of this study. This past year

(fall 2001) we observed resurgence of rootknot

nematodes near the end of the fall tomatoes with

all treatments.

Tomato plant vigor early in the season

during the fourth fall crop season was not affected

that much by treatment, other than the reduction in

vigor where no fumigant or alternative is used

(Table 1). By midseason plant vigor was reduced

some by soil solarization, but not to the extent as

observed in past years. Spring cropping practice

had no effect on fall tomato plant vigor during

2001.

Weed control was interesting this year

(Table 2). Both alternative treatments controlled

nutsedge as well as methyl bromide. Soil solariza-

tion had an advantage in that the nutsedge was

allowed to emerge through the mulch then was

burned off with Gramoxone Extra prior to trans-

planting tomatoes. The soil heating promoted

more of the tubers to germinate early so that the

Gramoxone weakened them and few

nongerminated tubers remained to replace them.

Also, it is believed that Devrinol aided nutsedge

control, even though it is not normally considered

particularly effective against nutsedge. Pigweed

has been observed to be a weed problem with

Tillam on some farms, but it was not in this study.

Control of pigweed was good with both alterna-

tives, although solarization was not quite as good

as the fumigants. Crabgrass continued to be a

problem with solarization, even after including

Devrinol this past fall in order to give solarization

some help with weed control. One explanation for

this may be the degradation of Devrinol over time

and the heating of the soil due to the opacity of the

clear mulch after painting prior to transplanting

tomatoes. Remember that Devrinol was already in

the soil for more than 2 months prior to planting,

thus we were nearing the end of its effective life in

the soil before we even began the crop. Last year

crabgrass did not appear until about midseason,

after what would normally be considered the life

expectancy of residual activity from Devrinol;

however, in 2001 crabgrass was present early and

there was an interaction between fall alternative

treatment and spring cropping practice for the

number of crabgrass plants present in October

(Table 3). As a result, the number of crabgrass

plants in each fall fumigant plot varied as to what

the spring crop had been. Solarization plots con-

tained more crabgrass than the fumigants or the

nonfumigated plots when used following spring

cucumbers, but following either millet or fallow

there was no difference in the number of crabgrass

plants between the nonfumigated and solarization.

Crabgrass numbers were comparable between

methyl bromide and Telone C-17 + Tillam +

Devrinol..

Fusarium wilt, race 3, infected 93% of the

nontreated control plants during the fall of 2001

(Tables 4). The incidence of fusarium wilt was

very low with methyl bromide and Telone C-17

(10 and 13%, respectively), whereas 53% of the

plants growing in solarized soil were infected.

These levels were very similar to what we saw last

year, suggesting that the relationship has matured

and numbers will remain fairly stable over the

coming year. Bacterial wilt and southern blight

were minor pests in this study and there was no

difference in their incidences. There was no effect

of spring cropping practice on fusarium wilt of

tomato in the following fall. This demonstrates

that the spring “crops” do not serve as hosts for

this pest.

Rootknot nematode population levels were

higher in plots treated with fumigants and no

fumigant than they had been during the fall of

2000, but the levels were lower than what was

observed in 2000 with solarization (Tables 5 and

50

6). (What may appear to be errors in these tables

are the result of transformation of data for analysis

but reporting nontransformed data. The letters

indicating the relationship among treatments are

correct.) Rootknot nematode populations did not

increase over time in the soil around the tomato

roots where no fumigant was used because there

were few live roots to support them as most of the

plants had been killed by Fusarium wilt. The most

rootknot nematodes were found associated with

roots grown in soil solarization plots. By the end

of the season, there were no differences among

treatments for the number of rootknot nematodes.

Both fumigants reduced the populations of stunt

and sting nematodes. Stubby root nematodes were

impacted by treatment just prior to first harvest,

but by the end of the season, there were no differ-

ences among treatments. Cyst nematodes have

been observed since early in the life of this study

and the numbers are slowly increasing. Cyst is an

important species and its presence allows the use

of higher than normal rates of Telone products. We

saw little effect of the spring cropping practice on

the pest levels or crop response in fall tomatoes,

with the exception of populations of ring nema-

todes where the least number were observed in

plots planted to millet in the spring and the most

were in those plots where double cropped cucum-

bers were grown. The production on galls on the

roots of tomatoes was greatest with no soil treat-

ment, intermediate with soil solarization and the

lowest with methyl bromide and Telone C-17

(Table 7).

The most important thing in tomato produc-

tion is what you put in the bucket and how it

grades out. Fruit were harvested twice during the

season and were sorted into cull and marketable

categories by hand, then were size graded using a

portable mechanical grader. The sorting criteria

were based on what two growers indicated would

be allowed during fall 2001 so as to assure our

criteria reflected not only the USDA grade stan-

dards, but also the local interpretation of those

standards. Telone C-17 + Tillam + Devrinol

produced as many tomatoes as methyl bromide in

each of the three size categories and total market-

able (Table 8). Production was reduced with soil

solarization + Devrinol compared to methyl bro-

mide or Telone C-17 with solarization falling

between no fumigation and methyl bromide.

Marketable fruit production with solarization was

about one-half of what it was with methyl bromide.

Double cropping is an important part of

tomato production for many growers as it provides

certain economies to the farming operation. Grow-

ers have questioned the future of double cropping

in the absence of methyl bromide. This long term

study also addresses that issue.

Cucumber was grown as a double crop the

following spring for each of the 4 years of this

study. Nutsedge control with Telone C-17 + Tillam

+ Devrinol was not different from that obtained

with methyl bromide, but solarization plots had

fewer nutsedge plants than methyl bromide (Table

9). This most likely was the result of reductions in

the overall tuber supply in the soil by heating the

soil to stimulate tuber sprouting, followed by

repeat applications of Gramoxone Extra to weaken

the plants or kill them. Interestingly the number of

nutsedge plants with methyl bromide were not

different from the nontreated control plot. The

population of crabgrass in cucumber plots was not

affected by fall fumigant practice. Pigweed was

reduced equally well by the two fumigants and

solarization.

Yield of double cropped cucumbers was the

greatest in solarized plots (Table 10). Unlike

previous years, there was no difference in cucum-

ber production between either fumigant and the

nontreated control treatment, while solarization

had significantly higher yields than the nontreated

control. Fall fumigation treatment did not affect

nematode populations with the exception of ring

nematodes which were more abundant where no

fumigant or solarization was used (Table 11).

Spring cropping practice impacted the populations

of several nematode species. Significantly more

rootknot, stubby root and ring nematodes were

present in areas where cucumbers were grown than

with millet or fallow. Stunt nematodes were

favored by fallowing the land.

Because differences in millet growth were

observed, millet tissue samples were collected and

analyzed for macro nutrient content. There were

no differences with the exception of Mg which was

the lowest in plants grown where no fumigant or

51

solarization had been applied over the past 4 years

(Table 12).

The implications of the results of this

project are that Telone C-17 (or Telone C-35)

combined with the appropriate herbicide can be as

effective as methyl bromide against soilborne pests

of tomato and can maintain that level of control in

the absence of methyl bromide. However, the

application of herbicide partners will require

greater attention to detail and selection of proper

application procedures and equipment. Nematode

control with Telone products can be as good as

with methyl bromide. Telone C-17 can control

Fusarium wilt as well as methyl bromide / chlo-

ropicrin mixtures when it is applied in the bed

using the same equipment as methyl bromide.

52

53

54

55

56

57

58

59

60

61

62

63

64

Development and Evaluation of aBiologically-Based System and aChemically-Based Alternative Systemto Methyl Bromide for TomatoProduction in Miami-Dade County.

Waldemar Klassen, Herbert H. Bryan, Robert T.

McMillan, Yuncong, Li, Q. R.Wang, A. Abdul-Baki,

M. Cadallo, Z. A. Handoo, D. Chitwood,

AbstractIn experiments at Homestead, FL tomato

yields in plots on which nematode-resistant cover

crops had been grown were comparable to those

grown on plots fumigated with methyl bromide-

chloropicrin. The cover crops were found to

strongly suppress various taxa of plant parasitic

nematodes and to spare non-parasitic and benefi-

cial taxa of nematodes. When irrigation was regu-

lated to maintain soil moisture tension near 30

cbars, tomato yields were significantly greater than

at 5 cbars. In addition at 30 cbars 70% less water

was consumed than at 5 cbars. KPAM when

injected into raised beds with injection shanks

spaced 8 inches apart suppressed nutsedge, root rot

pathogens and root knot nematodes as well or

better than methyl bromide-chloropicrin. Depend-

ing on KPAM dose, tomato yields in KPAM treated

beds were as great or greater than in MC-33 treated

beds. Automation of irrigation was not performed

because funds came too late, however this will be

done in the 2002-2003 season.

ObjectivesDuring the 2001-2002 winter production season,

conduct two randomized complete block experi-

ments each with four replicates at the Tropical

Research and Education Center:

A. Biologically-based system: identify the

most effective cover crop to be used in the crop/

optimized irrigation/plastic mulch system. Thus

tomato yields with sunn hemp, velvet bean, cow-

pea, sorghum Sudan and bare fallow will be deter-

mined.

B. KPAM system. Demonstrate the proper

use of KPAM, and compare its effectiveness to that

of methyl bromide plus chloropicrin.

C. In both systems, introduce the use of

automatic or switching tensiometers to precisely

control irrigation.

Experiment #1: Cover Crops as Alterna-tives to Methyl Bromide in Fresh MarketTomato Production in South Florida.

Investigators: Bryan, H. H., W. Klassen 5 Q.R.

Wang, A. Abdul-Baki, Y. Li and M. Codallo.

An experiment was conducted at the Tropical

Research and Education Center, University of

Florida, Homestead, to evaluate use of biological

alternatives to methyl bromide (MeBr) in growing

fresh-market tomatoes (Lycopersicon esculentum,

Mill). The biological alternative system consisted

of using ‘Sanibel’, a nematode resistant tomato

cultivar in 2000-2001 and ‘Leila’ a nematode

susceptible cultivar for 2001-2002; the nematode

resistant cover crops [cowpea (Vigna unguiculata

cv. Iron Clay), velvetbean (Mucuna deeringiana)

and sunn hemp (Crotalaria juncea cv. Tropic Sun)

in a cropping rotation. The experimental design

was planned to serve also as a demonstration, and

it employed 230-ft long treatment strips each

containing three raised beds. Samples of ten plants

were randomly selected per rep for yield determi-

nations. There were two cover crop treatments

(cowpea and velvetbean) and a methyl bromide

control treatment in 2000-2001. A third cover crop

treatment using sunn hemp was added in 2001-

2002. Two harvests were made in 2001 and three

in 2001-2002. Harvested fruits were graded fol-

lowing Florida Tomato Committee Standards, and

separated into extra large and total marketable.

The yields (tons/hectare) were as follows:

65

There were no significant differences in extra

large fruits among the MeBr and the cover crop

treatments in 2000-2001. Yields of extra large

fruits were higher in the cowpea and sunn hemp

treatments than in MeBr treatment in 2001-2002.

Total marketable yield in 2000-2001 was highest in

MeBr and lowest in cowpea. Total marketable

yield in 2001-2002 was significantly highest in

cowpea whereas, yields were similar in MeBr,

sunn hemp and velvetbean. In both years, the

percentage of extra-large fruits was very high and

total marketable yields of all treatments were

higher than average yields for South Florida. The

yields in 2001-2002 were affected by substantial

infections of Alternaria and target spot. The cover

crop treatments appear to offer a viable alternative

to MeBr and result in comparable yields at a lower

cost and less environmental hazard than MeBr.

Experiment #2. Influence of cover crops onsoil nematodes in a south Floridatomato field.

Investigators: Q. R. Wang, W. Klassen, Z. A.

Handoo, D. Chitwood, A. Abdul-Baki, H. H. Bryan

and Y. C. Li.

A field experiment was conducted to

evaluate the effects on populations of nematodes in

tomato plots on which three legume cover crops

(sunn hemp, Crotalaria juncea, velvetbean, Mu-

cuna deeringiana, and cowpea, Vigna unguiculata)

had been grown, and some kept as a weed-free

fallow and treated with methyl bromide-chloropi-

crin (MC-33). Sampling during tomato flowering

revealed that weed-free fallow followed by MC-33

strongly suppressed populations of plant-parasitic

nematodes (Helicotylenchus spp., Pratylenchus

spp., Rotylenchulus reniformis, and Quinisulcius

spp.), but some non-plant parasitic nematodes

(dorylaimids and rhabditids) survived. Sunn hemp

strongly suppressed the above-mentioned popula-

tions of the plant-parasitic nematodes, except,

Helicotylenchus spp., and also spared Tylenchus,

dorylaimids, Mononchus, and rhabditids.

Velvetbean strongly suppressed Aphelenchus,

Pratylenchus and Mononchus, but spared

Helicotylenchus spp., and small or moderate

populations of R. reniformis, Quinisulcius,

Tylenchus dorylaimids, and rhabditids. Cowpea

strongly suppressed all nematode taxa except the

rhabditids. By the time that the tomato fruit had

been harvested, the total numbers of nematodes

had increased in all of the treatments, so that the

increase was 852% in the cowpea treatment, 237%

in the weed-free fallow plus MC-33 treatment,

60% in the sunn hemp treatment and 10% in the

velvetbean treatment. In the cowpea treatment

most of the increase occurred in the non-plant

parasitic taxa. In the weed-free fallow plus MC-33

treatment, Aphelenchus and the dorylaimids has

increased the most followed by Helicotylenchus

and Pratylenchus. In the sunn hemp treatment, the

Helicotylenchus density and that of other taxa had

changed little. In the velvetbean treatment the

modest build up of Aphelenchus was the most

notable change. Unfortunately the plots were not

infested with any of the nematodes known to

severely reduce tomato yields in Florida, i.e., root

66

knot (Meloidogyne spp.), sting (Belonolaimus spp.)

and stubby root (Trichodorus spp.) nematodes.

Nevertheless these nematode-resistant cover crops

appear to be promising candidates as replacements

for methyl bromide in tomato production systems.

Experiment #3. Improved Tomato Produc-tion with Summer Cover Crops and Re-duced Irrigation Rates.

Investigators: Wang, Q. R., H. Bryan, A. Abdul-

Baki, W. Klassen, Y. C. Li, and M. Codallo.

To evaluate the effects of various cover

crops and irrigation rates on tomato production in

south Florida, a field experiment was conducted in

2001-2002 with 3 legume cover crops [sunn hemp

(Crotalaria juncea), cowpea (Vigna unguiculata)

and velvet bean (Mucuna deeringiana)], 1 non-

legume cover crop [sorghum Sudangrass (Sorghum

bicolor x S. bicolor)], clean fallow, and 4 irrigation

rates: 5, 10, 20 and 30 cbars. The cover crops were

planted on May 9, 2001. Two months later the sunn

hemp was flail-mowed at 30-cm above the ground

to promote branching, and the cowpea was flail-

mowed at ground level and reseeded. During the

first week of October, 2001 all of the cover crops

were flail-mowed and incorporated into the soil.

Each bed was provided with two drip lines and

covered with W/B plastic mulch. Tomato seedlings

were planted during the 3rd week of October. The

dry weights (Mt/ha) of biomass returned to the soil

were as follows: sunn hemp, 13.7; velvet bean,

11.0; cowpea, 12.0, and sorghum Sudan grass, 5.3.

The corresponding tomato total fruit yields (Mt/ha)

were: 61.3, 59.7, 51.0, 58.9, respectively, and 54.8

from the fallow treatment. The tomato fruit yields

were significantly greater with soil water tension

maintained near 30 than near 5 cbars. Water use

near 30 cbars, was 70% less than near 5 cbars.

Thus the use of sunn hemp and velvet bean and

reduced levels of irrigation can significantly

increase tomato yields and reduce water require-

ments.

Experiment #4. Evaluation of KPAM as anAlternative to methyl bromide inTomato production.

Investigators: R. T. McMillan, Jr., H. H. Bryan, W.

Klassen and M. Codallo.

The experiment was conducted on a tomato

grower’s field just east of Tamiami Airport in Mi-

ami-Dade County. The soil is much sandier than the

Krome gravely loam on which most tomatoes are

produced in Miami-Dade County. The experiment

was laid out as a randomized block replicated four

times. Each treatment consisted of a standard raised

bed 100 feet long and 6-feet wide (center-to-center).

The treatments consisted of an untreated control,

Methyl bromide-chloropicrin (MC-33) at 450 lb./

acre, KPAM at 50 gal/acre, and KPAM at 75 gal/

acre. On February 27 and 28, 2002 the MC-33 was

injected through four shanks 8-inches apart and 6-

inches deep; and the KPAM was injected 4 inches

deep through 6 shanks/bed. Florida 47 tomato seed-

lings were transplanted into the beds on March 16,

2002. The density of nutsedge in the untreated con-

trol was 2.5 plants per foot along the bed and about

40 percent of this density in beds treated with MC-

33 and with the lower rate of KPAM. Most of the

nutsedge plants in KPAM treated beds occurred on

the shoulders of the beds and distant from the pas-

sage of the most lateral injection shank. The yields

were as follows:

67

Immediately following the last harvest, the roots of ten plants in each bed were scored for root rot and root

knot nematode infections. The average scores were as follows:

xscoring was 0 to 5 with 0 was the best control and 5 was the worst.yColumn numbers with the same letter are not significantly different at P=0.05.

68

Manuscripts Prepared:

Bryan, H. H., W. Klassen 5 Q.R. Wang, A. Abdul-

Baki, Y. C. Li and M. Codallo. Cover.

Crops as Alternatives to Methyl Bromide in

Fresh-Market Tomato Production in South

Florida.

5 Wang* , Q. R., W. Klassen, Z. A. Handoo, D.

Chitwood, A. Abdul-Baki, H. H. Bryan and

Y. C. Li. Influence of cover crops on soil

nematodes in a south Florida tomato field.

(Presented at meeting of Soil and Crop

Science Society of Florida).

Wang, Q. R., H. Bryan, A. Abdul-Baki, W.

Klassen, Y. C. Li, and M. Codallo. Im-

proved Tomato Production with Summer

Cover Crops and Reduced Irrigation Rates

(Presented at meeting of Florida State

Horticultural Society).

Wang, Q. R., Y. C. Li* , and W. Klassen. Changes

of soil microbial biomass carbon and

nitrogen with cover crops and irrigation in

a vegetable field. Plant and Soil (submit-

ted).

69

Breeding Tomatoes for Florida

J. W. Scott

Gulf Coast Research & Education Center

University of Florida

5007 60th Street East

Bradenton, Fl 34203

AbstractSeveral hybrids are being considered for

release and are available for grower testing. These

include; Fla. 7973-fusarium race 3 resistant but

also for general use, Fla. 7964-spotted wilt resis-

tant, NC 99405 (HMX 1803)- heat tolerant,

jointless, fusarium wilt race 3 resistant, Fla. 7810

fusarium crown rot resistant, Fla. 7885B strong

heat-tolerance, Fla. 7943-fusarium wilt race 3

resistant and heat-tolerant, Fla. 7816-heat-tolerant,

and Fla. 7926-heat-tolerant. Outstanding inbreds

presently being used as parents include Fla. 8044-a

high lycopene line with superior heat-tolerance,

new fusarium crown rot resistant inbreds with high

lycopene (used in F1’s 8084 and 8085 now in

limited grower trials), and a new spotted wilt

resistant inbred. Fla. 8109 is a bacterial wilt resis-

tant line with large fruit and could represent a

break in a linkage of resistance to smaller fruit

size. Geminivirus resistance breeding is progress-

ing well, but it will be a few years before hybrids

are ready for advanced and grower testing. Fla.

8059 is an inbred that has a high level of firmness

and other good characteristics including high

lycopene and flavor. It may have some commercial

applications in the near future in competing with

cluster tomatoes in the market. Compact growth

habit hybrid Fla. 8107 performed well at GCREC

and TREC and will be tested on grower farms as a

prototype for stake-less production.

IntroductionImproved varieties are needed to keep the

Florida tomato industry competitive in a changing

world. Improvements include the areas of yield,

pest resistance, and fruit quality. Florida’s geogra-

phy offers many challenges for tomato improve-

ment, since high temperatures limit fruit set and

are conducive to disease and insect problems.

There are no neighboring states with similar

latitudes to most of Florida, so there is less help in

solving agricultural problems than is the case in

many states. Although private companies have

tomato breeding programs that develop varieties

for Florida, these companies are not set up to

handle many of the long term, high risk projects

that could prove valuable in the future. The Uni-

versity of Florida tomato breeding program aims at

such projects and works in partnership with the

private companies to deliver improved varieties of

benefit to the Florida tomato industry. Much of

the groundwork for the development of heat-

tolerant varieties was done at the University of

Florida (Scott et al., 1986). ‘Solar Set’ has been an

important commercial, heat-tolerant variety for 11

years after it’s release (Scott et al., 1989). We now

have Fusarium wilt race 3 resistant varieties using

a resistance gene discovered in a wild species by

this program in the 1980’s (Scott and Jones, 1989).

Breeding lines with Fusarium crown and root rot

resistance have recently been released (Scott and

Jones, 2000) and varieties ought to be available in

a few years. With the impending loss of methyl

bromide, these pathogens could become more

widespread. Other diseases such as bacterial wilt

and spotted wilt occur in Florida, but cause far

more damage in other regions of the world. If

something changes and these diseases become

more prevalent, Florida would benefit from resis-

tant varieties. Geminiviruses like tomato mottle

(ToMoV) and tomato yellow leaf curl virus

(TYLCV) pose a threat to Florida tomato produc-

tion. Other regions have these or other

geminivruses (Polston and Anderson,1997). A

project has been ongoing since 1990 utilizing

resistance genes from a wild species. It appears

that four genes have been introgressed, and these

genes may well be useful in solving the long term

geminivirus problems that Florida will likely face.

Tomatoes have met with considerable dissatisfac-

tion in the marketplace. Essentially, this relates to

compromises that are made in providing fruit that

will ship well. Solutions to this problem are not

simple. Research is needed to provide tomatoes

that will be more acceptable to consumers. On the

bright side, recent medical literature has shown

70

that lycopene, the red pigment in tomato, has

strong antioxidant properties that reduce several

cancers. Work in the breeding program has been

ongoing for 18 years with a crimson gene (ogc) that

improves internal tomato color and increases

lycopene by 50%. Crimson varieties could be a

boon to the Florida industry in the not too distant

future. Genetic alteration of plant architecture

might provide varieties for mechanical harvest or

reduced costs in manual labor and equipment. This

could be critical for future production in Florida.

This is another long-term, high risk project that is

being pursued in my program that is not likely to

be attempted by the private sector. Funding of the

Florida Tomato Committee has been imperative to

the operation of this breeding program, an invest-

ment that has and will continue to pay dividends.

Objectives of this project were:

1) To develop varieties or breeding

lines resistant to soil borne

pathogens.

2) To develop improved heat-tolerant

inbreds and hybrids.

3) To develop commercially accept-

able breeding lines and hybrids

resistant to geminiviruses or spotted

wilt virus.

4) To improve fruit quality and

postharvest characteristics.

5) To develop commercial hybrids for

the Florida tomato industry.

Objective 1

MethodsThere were 74, 65, and 11 lines screened

for Fusarium wilt race 3 in fall 2001, spring 2002,

and summer 2002, respectively. Twenty-two F1’s

were evaluated for the first time. There were 44,

61, and 7 lines screened for Fusarium crown rot in

fall 2001, spring 2002, and summer 2002, respec-

tively. There were 16 and 71 lines inoculated with

the bacterial wilt pathogen and evaluated in spring

and summer 2002, respectively. In spring 2002, a

yield trial comparing advanced inbreds was con-

ducted that included 5 lines resistant to race 3 and

1 line resistant to fusarium crown rot. Several

hybrids with resistance to race 3 or crown rot were

evaluated in state -wide and observation trials in

fall 2001 and spring 2002. Seven bacterial wilt

resistant inbreds are being tested for resistance and

fruit size in a replicated trial where they are being

compared to control lines. All were inoculated with

the bacterial wilt pathogen.

ResultsFla. 7946, a Fusarium wilt race 3 resistant

inbred, has continued to perform well as it did the

previous year. It was crossed with NC 84173 to

make hybrid Fla. 7973. This hybrid has performed

well consistently in 2001 and 2002. It does not

have heat-tolerance so is not recommended in early

fall crops but should be considered in all other

growing seasons even if race 3 is not a problem. It

will likely be released in fall 2002. Fla. 7810 is

heat-tolerant and resistant to fusarium crown and

root rot. It has done consistently well in observa-

tion trials over several years and is now being

tested in replicated and grower trials. Two inbreds

with race 3 resistance are in Syngenta hybrids that

are soon to be released. These hybrids have resis-

tance to fusarium crown rot as well which comes

from the Syngenta side of the cross. Hybrids with

crown rot resistance are also being made using

some outstanding inbreds that have been developed

using Fla. 7781, a breeding line release from 1999

and a line from North Carolina. Fla. 8109 is a

bacterial wilt line that has large fruit with resis-

tance similar to Hawaii 7997, the small fruited

source of resistance. Apparently a linkage between

resistance and small fruit size has been broken.

This could bring on a new era in developing

bacterial wilt resistant varieties because up to now

it has not been possible to develop large fruited

varieties with a high level of resistance.

Objective 2

MethodsHeat-tolerant (HT) fruit setting ability is

being incorporated into all phases of the breeding

program. In spring 2002, 25 HT inbreds were

evaluated for their performance under non-heat

stress conditions. In summer 2002, 94 HT lines are

71

being evaluated under high temperature conditions.

There were 47 crosses with HT recurrent parents

made in fall 2001 and spring 2002. In the spring

2002 yield trial mentioned under Objective 1, 7 of

the lines tested were experimental HT lines. In

summer 2001, a yield trial was conducted to

evaluate HT inbreds and hybrids. Numerous HT

hybrids were tested in fall and spring replicated or

observation trials. Seven HT lines are being tested

in the same replicated trial mentioned under the

bacterial spot project for summer 2002.

ResultsFla. 7885B has two heat-tolerant parents

and is a week earlier than other heat-tolerant

hybrids under high temperature growing condi-

tions. It has smooth fruit and performs well during

all growing seasons in Florida. It also has excep-

tional vine cover. It is being considered for release

by testing in state-wide and grower trials.

NC99405, a jointless ,heat-tolerant, fusarium wilt

race 3 resistant hybrid has tested well in replicated

and grower trials, but the fruit may not hold firm-

ness after table ripe as much as desired and this

could preclude release. Growers should test this

experimental hybrid under their conditions. In

general, fruit set was not good in summer 2001 in

that lines that generally set well did not. However,

a new line Fla. 8044 had exceptional fruit set. Fruit

had good size, firmness, smoothness, and internal

color due to the crimson gene. In spring 2002, Fla.

8044 was a week earlier that all other large fruited

lines or hybrids. It had significantly greater yield

than all other genotypes tested and fruit size was

comparable to ‘Florida 47’. Hybrids were made

with 8044 and it is anticipated that one or more

will be released rather soon. Such a hybrid should

provide growers with a more reliable yielding

variety that those presently available and thus

should have a major impact on the Florida variety

picture.

Objective 3

MethodsThere were 331 and 309 lines inoculated

separately with ToMoV and TYLCV, rated for

disease severity, and evaluated for horticultural

type in fall 2001 and spring 2002, respectively.

There were 50 and 115 hybrids with a ToMoV

resistant parent that were evaluated in fall 2001

and spring 2002, respectively. Some of the most

resistant lines with better horticultural characteris-

tics were tested in replicated trials that were inocu-

lated separately with ToMoV and TYLCV in

spring 2002. These trials allow for statistical

comparisons of the lines which helps to determine

the best resistance sources.

There were 44 and 50 inbreds with spotted

wilt resistance evaluated in fall 2001 and spring

2002, respectively. There were 38 and 18 hybrids

made in fall 2001 and spring 2002, respectively.

There were 6 spotted wilt resistant hybrids evalu-

ated in the spring at GCREC. Fifteen hybrids and

9 inbreds (using a different resistance source) were

evaluated in an experiment at NFREC. Selection

for resistance is done with sequence characterized

amplified region (SCAR) molecular markers that

eliminate the need to screen with thrips and poten-

tially spread the virus in the west coast growing

region.

ResultsThere were 255 geminivirus resistant

selections made in the fall and 50 F1’s were ad-

vanced. In spring 2002, 230 selections were made

and 47 F1’s were advanced. Most lines now have

determinate plant habits and good fruit set. A few

inbreds appear to be near the horticultural at-

tributes needed to make commercial hybrids.

Resistance will have to be bred into both parents of

a hybrid variety to insure the best resistance level,

since inheritance is primarily additive. The ToMoV

and TYLCV replicated trials and breeding plots

indicated that almost all of the lines resistant to

ToMoV were also resistant to TYLCV. Several

lines had greater TYLCV and ToMoV resistance

than PX 150535. Progress was made in locating

molecular markers closely linked to the resistance

genes but this work is not complete yet. Good

molecular markers would speed up the breeding

process. With or without the markers, it is antici-

pated that experimental hybrids will be available

for grower testing within the next 2 years.

Fla. 7964 has performed the best of the

72

spotted wilt resistant hybrids being trialed. It

looked good in North Carolina in summer 2001

and has been comparable to other spotted wilt

resistant hybrids in replicated trials at GCREC and

NFREC in fall 2001 and spring 2002. Some

spotted wilt resistant inbreds have shown improve-

ment over existing lines as hybrid parents. These

hybrids are ready for more advanced testing.

Spotted wilt resistance is important to Tomato

Committee members who grow in North Florida or

elsewhere in the southeastern US at present. It will

also be important if this disease becomes more

serious in the peninsula of Florida.

Objective 4

MethodsFruit quality and shelf-life are emphasized

in all breeding projects. One method to improve

shelf-life is to develop varieties with a high level

of firmness that we call ultrafirmness. Another

method is to incorporate the ripening inhibitor (rin)

gene in firm genetic backgrounds and make

heterozygous rin hybrids. In fall 2001, 28 ultrafirm

(UF) inbreds were evaluated. In spring 2002, 18

UF lines, 21 UF F1’s, and 22 rin hybrids were

evaluated.

Another aspect of fruit quality is the devel-

opment of high lycopene varieties by using the

crimson (ogc) gene. This gene is widely distributed

in the various breeding projects. New hybrids are

continually being made and evaluated.

There were 64 and 62 lines evaluated

primarily for improved flavor in fall 2001 and

spring 2002, respectively. High sugars are also

being incorporated from cherry sized lines to large

fruited lines for flavor improvement. In fall 2001,

56 high sugar hybrids were made and 29 lines were

evaluated for sugars in fall 2001 and spring 2002.

The most interesting lines from all flavor work are

put in flavor trials described in the grant report

with Dr. Elizabeth Baldwin.

Another project is to develop tomatoes that

do not require staking by use of the brachytic (br)

gene that reduces plant height and increases side

shoots. These tomatoes are called compact growth

habit (CGH) tomatoes. Many are very firm. In fall

2001, 38 CGH lines were evaluated, 21 F1’s were

advanced, and 19 hybrids were made. There were

28 CGH lines evaluated in spring 2002 and 59 F1’s

were evaluated and advanced to F2. In winter 2002,

40 CGH lines were evaluated in at TREC.

ResultsIt has been difficult to obtain UF lines with

good flavor characteristics, but there do seem to be

a few lines with good flavor based on data over

two years. Fla. 8059 is such a line and it is pres-

ently being tested in a replicated trial to verify it’s

firmness and flavor. Flavor is also emphasized in

the rin project since rin/+ hybrids often have poor

taste. For this reason there was less work done with

rin this year. After considerable trials over many

seasons, it appears that crimson lines often have

good flavor, but are not high in acidity. This can

result in a somewhat bland flavor under some

conditions. Recent work has emphasized crimson

lines with greater acidity to overcome this prob-

lem. Twenty-one F2’s and 14 F

3’s were evaluated in

fall 2001 and spring 2002, respectively to improve

ogc acidity. New crimson hybrids are evaluated

each season and compared to existing ones that

have done well in the past such as Fla. 7862 and

Fla. 7945.

Fla. 8107 is a CGH hybrid that performed

well at TREC and GCREC in 2002. This hybrid

will be used as a prototype for stake-less tomato

production in Homestead in sequential plantings

during the 2002-2003 season. Emphasis is being

placed on jointless lines that could result in ma-

chine harvest varieties, but these are not as ad-

vanced horticulturally.

Objective 5

MethodsHybrids are evaluated for horticultural type

in breeding plots each season with two replicates

for those that are expected to have commercial

potential. After the initial evaluation, those selected

for further testing are put in observation trials at

GCREC and NFREC, with some also being tested

at TREC. Those that perform well in the observa-

tion trials are tested in state replicated trials (at the

73

3 above centers and IRREC) and in trials on

growers farms. For seed production, it is hoped

that the initial crossing produces enough seed for

the first two evaluations. When a hybrid moves

onto the advanced trial phase more seed is pro-

duced.

ResultsExperimental hybrids being seriously

considered for release include Fla. 7973, Fla. 7810,

Fla 7885B, NC 99405, and Fla. 7964, mentioned

previously. Others include Fla. 7943 a heat-tolerant

fusarium wilt race 3 hybrid, heat-tolerant hybrids

Fla. 7926 Fla. 7816, and Fla.7978, and compact

growth habit hybrid Fla. 8107. Many others are in

the second phase of testing and some of these will

be available for grower tests in 2003.

Literature Cited

Polston, J. E. and P. K. Anderson. 1997. The emer-

gence of whitefly-transmitted geminiviruses

in tomato in the Western Hemisphere. Plant

Dis. 81: 1358-1369.

Scott, J. W., and J. P. Jones. 1989. Monogenic resis-

tance in tomato to Fusarium oxysporum f. sp.

lycopersici race 3. Euphytica 40:49-53.

Scott, J. W., and John Paul Jones. 1995. Fla. 7547

and Fla. 7481 tomato breeding lines resistant

to Fusarium oxysporum f. sp. lycopersici

races 1,2, and 3. HortScience 30(3):645-646.

Scott, J. W., and John Paul Jones. 2000. Fla. 7775

and Fla. 7781: Tomato breeding lines resis-

tant to Fusarium crown and root rot.

HortScience 35(6):1183-1184.

Scott, J. W., S. M. Olson, J. J. Bryan, T. K. Howe, P.

J. Stoffella, and J. A. Bartz. 1989. Solar Set:

A heat tolerant, fresh market tomato hybrid.

Fla. Agric. Expt. Sta. Circ. S-359 10p.

Scott, J. W., R. B. Volin, H. H. Bryan, and S. M.

Olson. 1986. Use of hybrids to develop heat

tolerant tomato cultivars. Proc. Fla. State

Hort. Soc. 99:311-314.

74

Breeding Tomatoes for Resistance toall Three Races of the BacterialSpot Pathogen

J. W. Scott

Gulf Coast Research & Education Center

University of Florida

5007 60th Street East

Bradenton, FL 34203

J. B. Jones

Plant Pathology Department

University of Florida

Gainesville, FL 23611

AbstractThree of four races of the bacterial spot

pathogen that infect tomato are in Florida with race

T3 being the most important. Resistance to race T3

has been incorporated into improved heat-tolerant

breeding lines and some of these should be accept-

able as parents to make commercial hybrids.

Testing of hybrids in summer 2001 was not opti-

mal because plants did not grow well due to fertil-

izer leaching. Most hybrids tested in spring 2002

were not up to commercial standards, but a few

were better and are presently being retested along

with about 62 new hybrids. Inbreds with T3 or T3

plus T1 resistance are being evaluated for resis-

tance and horticultural type this summer. Lines

with broad spectrum resistance derived from PI

114490 are also being developed with a small

number having potential as parent lines. Separate

genes were found to control T2 and T3 resistance

from PI 114490.

IntroductionBacterial spot is still the most ubiquitous

disease problem of tomatoes in Florida. Four

tomato races of Xanthomonas campestris pv.

vesicatoria (Xcv), causal agent of bacterial spot,

have been discovered to date (Astua-Monge et al.,

2000; Jones et al., 1995). In Florida, there are

three races, the original race (T1), the race discov-

ered in 1991 (T3) (Jones et al., 1995), and a new

race (T4)(Astua-Monge et al., 2000). Race T3 has

largely replaced race T1 in Florida (Jones et al.,

1998). Race T4 has mutated from T3 and has been

found in Dade and Manatee counties. It is not

known how important this race is now or might

become should race T3 tolerant varieties be com-

mercially grown. Race T2 was originally reported

from Brazil, but has now been isolated in some

states in the USA including Ohio.

Our breeding project began in 1983 when

we found Hawaii 7998 was resistant to race T1

(Jones and Scott, 1986). More recently resistance

to race T3 was discovered in several accessions

including Hawaii 7981 (Scott et al., 1995), and this

resistance has been incorporated into advanced T1

resistant breeding lines. Lines with resistance to

T1 and T3 also had tolerance to race T2, whereas

lines with resistance to either race alone were

susceptible to T2. This suggests combining bacte-

rial resistance genes in a line may have unexpected

beneficial effects against other bacterial races. We

found PI 114490 was resistant to race T2 in the

summers of 1995 and 1996 (Scott et al., 1997) and

this was further verified from 1997 through 2001 at

Wooster, Ohio. PI 114490 also was resistant to

race T1 and tolerant to race T3. It is not known if

PI 114490 has resistance to race T4. The general

T2 resistance from PI 114490 needs to be incorpo-

rated into advanced breeding lines. This general

resistance could be important should race T2

migrate into Florida. The use of varieties with

such resistance might also protect against any new

race which might emerge in the future. The objec-

tives of this research were:

1) To develop commercial hybrids with

tolerance to bacterial spot races T3 and

T1.

2) To incorporate general Xcv resistance

from PI 114490 into advanced breed-

ing lines.

3) To combine new T2 resistance genes

with known resistance genes.

Objective 1

MethodsIn summer 2001, 154 breeding lines (F

2 and

more inbred) and 67 hybrids with resistance were

inoculated with race T3 and evaluated in the field.

Nine hybrids were evaluated in the fall. Also in the

75

fall, 2 hybrids heterozygous for bacterial spot

resistance were evaluated in advanced observa-

tional trials at NFREC. Some of the hybrids were

evaluated for commercial potential and some were

made to recombine traits from two resistant par-

ents. In spring 2002, 43 F1’s with some resistance

to races T1 and T3 were evaluated in breeding

plots and 21 of these were also evaluated in a yield

trial. Additionally, 11 inbreds were evaluated in

breeding plots and 5 inbreds were evaluated in a

yield trial for horticultural type in the spring. At

Homestead (TREC), 30 lines with bacterial spot

resistance were evaluated in winter 2002. In

summer 2002, 130 breeding lines (F2 and beyond)

are being evaluated that have T3, or T3 and T1

resistance. Also this summer, 68 F1’s are being

evaluated. Two inbreds and 1 hybrid are being

evaluated in replicated trials this summer.

ResultsIn summer 2001, 43 selections were made

for lines with race T1 and T3 resistance and 30

lines were selected with only T3 resistance. There

were 27 selections with T1 and T3 resistance

combined with resistance from PI 114490. In

spring 2002, 22 selections were made and 11 F1’s

were advanced to the F2 generation. At Home-

stead, 17 selections were made with T1 and T3

resistance. Many resistant inbreds are too small

fruited to be used as parents in commercial hy-

brids. However, some inbreds appear to have

potential as parents and these are in hybrids being

tested at present. It was difficult to evaluate the

hybrids tested in summer 2001 because fertilizer

had leached out of the beds and the plant growth

was not good. To further complicate matters, notes

taken on a field computer were lost in a computer

mishap. Overall, the hybrids tested in spring 2002

were disappointing, although some were consid-

ered worthy of continued trialing including the 1 in

the yield trial. Critical testing of hybrids is pres-

ently taking place and hopefully accurate assess-

ments will be made. Any hybrids showing potential

will be widely tested in 2003 in University and

grower trials with a release made as soon as fea-

sible if results are good.

Objective 2

MethodsIn summer 2001, 157 breeding lines with

resistance from PI 114490 were evaluated in

Bradenton. Also, an experiment was conducted

testing 85 linbred backcross lines for resistance to

races T2 in Ohio and T3 in Bradenton. In Winter

2002 1 of the bacterial spot resistant lines men-

tioned in objective 1 had resistance from Hawaiian

sources combined with PI 114490. In summer

2002, 104 inbreds with PI 114490 resistance are

being evaluated for T3 resistance. Two inbreds

with combined Hawaiian and PI 114490 resistance,

and 1 inbred with only PI 114490 resistance are

being tested in a yield trial.

ResultsThere were 72 selections made in summer

2001. In general, we have found that resistance

from PI 114490 is very effective for races T1 and

T2 and less effective for T3. The segregation of

inbreds from the inbred backcross populations

indicated that different genes confer resistance to

race T2 and T3 (Scott et al., in press). A few

inbreds are looking good horticulturally and these

are being tested in the yield trial. The best lines of

those being tested this summer will be tested for

T1 and T2 resistance in Ohio next year. They will

also be tested for T4 in Gainesville greenhouse

tests. Emphasis will be placed on lines with broad

based bacterial resistance.

Objective 3

MethodsPreviously, resistance was found in LA

1682 and LA 1684. Crosses were made between

these two accessions and LA 442 and PI 114490,

respectively. The leaf dip test was used on F2’s

from these crosses and selections were made for

improved resistance. Seed from these selections

have been planted in Summer 2002 and they will

be tested for resistance to T3 in the field.

ResultsThe lines are presently being tested and

results are not available at this time.

76

Literature Cited

Astua-Monge, G., G.V. Minsavage, R.E. Stall,

Eduardo C. Vallejos, M.J. Davis, and J. B.

Jones. 2000. Xv4-avrxv4: A new gene -for-

gene interaction identified between

Xanthomonas campestris pv. vesicatoria race

T3 and the wild tomato relative Lycopersicon

pennellii. Molecular Plant-Microbe Interac-

tions 13(12):1346-1355.

Jones, J.B., H. Bouzar, G. C. Somodi, R.E. Stall, K.

Pernezny, G. El-Morsy, and J.W. Scott. 1998.

Evidence for the preemptive nature of tomato

race 3 of Xanthomonas campestris pv.

vesicatoria. In Florida. Phytopathology.

88:33-38.

Jones, J.B. and J.W. Scott. 1986. Hypersensitive re-

sponse in tomato to Xanthomonas campestris

pv. vesicatoria. Plant Dis. 70:337-339.

Jones, J.B., R.E. Stall, J.W. Scott, G.C. Somodi, H.

Bouzar, and N.C. Hodge. 1995. A third to-

mato race of Xanthomonas campestris pv.

vesicatoria. Plant Dis. 79:395-398.

Scott, J.W., J.B. Jones, G.C. Somodi, and R.E. Stall.

1995. Screening tomato accessions for resis-

tance to Xanthomonas campestris pv.

vesicatoria, race T3. HortScience 30:579-

581.

Scott, J. W., S. A. Miller, R. E. Stall, J. B. Jones, G.

C. Somodi, V. Barbosa, D. L . Francis, and

F. Sahin. 1997. Resistance to Race T2 of

the bacterial spot pathogen in tomato.

HortScience 32(4):724-727.

77

Selection of Tomato Lines forCommercial Markets That Exhibit aFruity/Floral Flavor Character Within aBalance Sugar, Acid and Volatile Profile

Elizabeth A. Baldwin

USDA/ARS Citrus & Subtropical

Products Laboratory

Winter Haven, FL

J.W. Scott

University of Florida Gulf Coast

Research & Education Center

Bradenton, FL

AbstractTomato fruit were grown in statistical plots

and the University of Florida Gulf Coast Research

and Education Center. Fruit were analyzed by

sensory panels for flavor rating (consumer panel),

flavor descriptors (trained panel) and chemical

components including color, lycopene, sugars,

acids, and aroma volatiles. Cultivars that had been

fixed over several seasons for an optimum sugar/

acid balance and a fruity/floral character were rated

high by a consumer panel and were found to be

high in sugars, acids and aroma compounds. The

spiking study showed certain volatiles were associ-

ated with specific flavor descriptors.

IntroductionThe tomato industry is facing serious

economic pressures from “vine-ripe” imports from

Mexico and greenhouse-grown fruit from Canada

and Europe. Consumers are obviously willing to

pay a high price for a quality product as evidenced

by the cost of specialty tomatoes (cluster tomatoes,

hydroponically-grown fruit, etc.) displayed in the

supermarket. The industry would gain market

share if a premium tomato product, that combined

the health benefits of high lycopene and improved

flavor quality, were developed.

In this study, We continued to look at

cultivars developed from high lycopene back-

grounds with good horticultural characteristics and

a fruity/floral flavor note that would differentiate a

potential release from the rest of the fresh tomato

market. High lycopene tomatoes may garner

health benefits due to the anti-oxidant, anti-cancer

activity of lycopene (Nguyen and Schwartz, 1999).

Furthermore, the lycopene pigment is responsible

for the red color of tomatoes, and serves as a

precursor for important flavor compounds (Buttery

and Ling, 1993; Buttery et al., 1999). This means

that high lycopene cultivars may result in healthier,

better flavored, and more attractive tomatoes.

MethodsTomato (Lycopersicon esculentum Mill.)

cultivars were grown in a completely randomized

block design with three blocks and ten plants per

plot at the University of Florida Gulf Coast Re-

search and Education Center in Bradenton in fall

and spring of 2001 and 2002, respectively. Culti-

vars, were sampled in the field from three blocks,

and informally evaluated for flavor by the breeder

and one technician. From this screening, cultivars

were selected for sensory and instrumental/chemi-

cal analysis to represent a range in flavor for

comparison to lines that have been fixed over

several seasons for specific fruity/floral flavor

notes with a high lycopene background.

Tomatoes were analyzed by an experienced

panel of 30+ panelists who sampled tomato

wedges representing at least 5 fruit per cultivar.

Sub samples were taken 3 times during the panel

session and analyzed for color and flavor compo-

nents by measurement of solids, sugars, acids and

aroma compounds by refractometer, HPLC, titra-

tion, and gas chromatography (GC) (Baldwin et al.,

1998). Color and pigment analyses were done on

tomato homogenate using a Minolta chromameter

and a scanning spectrophotometer at 450-650 nm

which is the range of absorption spectra for lyco-

pene. For the trained panel, 6-8 members sampled

bland tomato homogenate from the fall season

spiked with food grade aroma compounds.

ResultsConsumer panel data confirmed the assess-

ment of the cultivars by the breeder (Table 1).

Three lines were rated high for overall flavor

including 404, 418, and 420. Cultivars 404, 418

and 420 also were rated high in sweetness along

with 406; and 404 and 418 were rated high in

78

acidity along with ‘Solar Set’. For chemical analy-

sis, 404 and 418 were highest in soluble solids

(SS); 404 and 418 were highest also in total sugars

along with 423; and 404 and 418 were highest in

sucrose equivalents (SE, a measure of sweetness

based on actual sugar levels) and 420 was highest

in SS/TA. Cultivars 404 and 418 were highest in

titratable acidity (TA); (Fig. 1). Cultivars 404,

418, and to a lesser extend 420 were high in alde-

hydes, many ketones, alcohols, isobuthylthiazole

and 2-nitro-phenylethane (particularly cultivar 418

that was selected for the fruity/floral note) (Fig. 2).

Cultivar 406 was also high in many volatiles and in

lycopene (Fig.1), as it has the crimson (ogc) gene.

Conversely, cultivar 424 (bland according to

breeder) was rated low in sweetness, acidity, and

flavor; and was low in SS, sugars, TA and all

volatiles.

Trained panel was used to determine the flavorimpact of individual food grade aroma volatilesthat were spiked into bland tomato homogenate.The main aromas were grouped into “green/grassy”, “fruit”, “floral”, “earthy” and “musty”;

which related to certain groups of aroma com-pounds (Table 2). It was found that spiking blandtomato homogenate with certain aroma compoundsaffected panelist perception of sweetness andsourness, even though sugar and acid levels werenot changed.

79

In conclusion, selection of high flavoredlines, and especially those with a fruity floral notein a balanced sugar/acid background continued.The goal is to obtain a variety stable for this flavorprofile in order to develop a consistent premiumtomato for release to Florida growers.

Literature Cited

Baldwin, E. A., J.W. Scott, M.A. Einstein, T.M.M.

Malundo, B.T. Carr, and R.L. Shewfelt, and

K.S. Tandon. 1998. Relationship between sensory

and instrumental analysis for tomato flavor.

J. Amer. Soc. Hort. Sci. 123: 906-915.

Buttery, R.G. and L. Ling. 1993b. Volatile com-

ponents of tomato fruit and plant parts:

Relationship and biogenesis, p. 22-34. In:

R. Teranishi, R.G. Buttery, and H.

Sugisawa (eds.). Bioactive

Volatile Compounds from Plants. Amer.

Chem. Soc., Washington, DC.

Buttery , R.G., R. Teranishi, R.A. Flath, and L.C.

Ling. 1989. Fresh tomato volatiles:

Composition and Sensory Studies, p. 213-

222. In: R. Teranishi, R.G. Buttery, and F.

Shahidi, (eds.). Flavor Chemistry, Trends

and Developments. American Chemical

Society, Washington, DC.

Nguyen, M.L. and S.J. Schwartz. 1999. Lyco-

pene: Chemical and biological properties,

Food Technol. 53(2): 38-45.

Figure Legends

Fig. 1 Color (hue [H] angle), lycopene, titratable

acidity (TA), percentage soluble solids (%SS), SS/

TA ratio, total sugars, and sucrose equivalents (SE)

for tomato lines grown at Bradenton, Florida in

spring, 2002. For line descriptors see Table 1.

Fig. 2 Volatile aldehydes (A), ketones (B), alcohols

(C), and miscellaneous (D) for spring 2002 tomato

lines, see Table 1 for line descriptors.

80

81

82

83

Mining gold in Florida: Feasibility oflycopene and novel by-productsrecoveries from cull tomatoes via post-harvest manipulations, dehydration andCO2 super critical extraction

Amy Simonne1, Bala Rathinasabapathi2,

Stephen T. Talcott3, Steven A. Sargent4, Jeff

Brecht4, Murat Balaban5, and Maurice R.

Marshall5. 1Assistant Professor, Department of

Family, Youth and Community Science, Institute of

Food and Agricultural Sciences, University of

Florida, P.O. Box 110310, Tel: 352-392-1895, Fax:

352-392-8196, email: asimonne@mail.ifas.ufl.edu

(Main contact), 2Assistant Professor, Department

of Horticultural Sciences, 3Assistant Professor,

Department of Food Science and Human Nutrition,4 Professor, Department of Horticultural Sciences,5 Professors, Department of Food Science and

Human Nutrition

Collaborators:Teresa Olczyk, M.S., Extension Agent II. Dade

County (District V)

Eugene (Gene) McAvoy, M.S., Extension Agent II.

Hendry County (District V)

Phyllis R. Gilreath, Ph.D., Extension Agent IV.

Manatee County (District IV)

Joshua Mayfield, M.S. Extension Agent I. Gadsden

County (District I)

AbstractCull tomatoes, from green through pink

stages, can be successfully ripened over a 10-day

period. Green tomatoes ripened to red-ripe stage

during 10 days of gassing, and tomatoes that were

initially pink did not become excessively over-ripe

during this period of time. For ripening of cull

tomatoes to be feasible under packinghouse condi-

tions, there must be little additional labor required

to prepare the tomatoes for ripening and subse-

quent operations. For this reason the cull tomatoes

were carefully sorted by the defect categories.

The results show that the culls must be

sorted (prior to gassing for green fruit). In fact,

only tomatoes that were free of minor defects (i.e.,

“sound” category) ripened without decay (see

Table 4). Green tomatoes with catface had only

6.3% decay and possibly could be included. How-

ever, green and pink tomatoes with cuts and

growth cracks had from 17.0% to 39.6% decay by

Day 10.

The number of culls that were considered

sound was about 20% of the total, based on 33%

sound green and pink tomatoes out of 62.9%

usable tomatoes (see Table 2). An additional 6% of

cull green tomatoes had minor catface (10% of

62.9%) and could also be included. Thus, for a

typical random sample of cull tomatoes, about 39%

of them would be suitable for lycopene extraction.

We have investigated whether culled toma-

toes of the popular cultivar FL-47 can be used as a

source of the red pigment lycopene. We found that

stage 4 “sound fruits” and “culled fruits with cracks”

developed significantly more lycopene in their fruit

walls than fruits with other defects such as cuts and

catface (200 to 300 mg per g versus 100 to 140 mg

per g). A standard ethylene treatment (100 ppm, at

20 EC for 10 days) significantly elevated the lyco-

pene levels in some categories of fruit and not in oth-

ers. Outer tissues, which contributed 10 to 15% of

the total fruit weight, had about three-fold more ly-

copene than the rest of the fruit tissue on a fresh

weight basis (100 to 300 mg per g versus 30 to 80

mg per g).

Our results suggest that (1) culled tomatoes

with various defects can be pooled together and ex-

posed to ethylene for lycopene accumulation. And

(2) there is potential to extract about 200 mg lyco-

pene from every kilogram of outer tissue and about

50 mg lycopene from every kilogram of other fruit

tissue. Based on our preliminary run, it is possible to

extract lycopene from cull tomato tissues by CO2

supercritical fluid extraction. However, additional

studies are needed to manipulate samples and ex-

traction parameters, to obtain the best recovery of

lycopene.

No difference in phytochemical concentra-

tions or antioxidant capacity was found due to ethyl-

ene exposure, and no appreciable difference was

found due to preharvest selection of fruit (see Table

6.). However, outer tissue layers generally had higher

levels of total soluble phenolics (Folins) and fla-

vonoid glycosides that related to higher ORAC val-

84

ues. Levels of hydroxybenzoic and hydroxycinnamic

acids were not different between tissues.

Objective 1To explore the feasibility and possibility of

recovering lycopene and phenolic compounds from

cull or non- marketable tomatoes grown in Florida

using CO2 supercritical extraction (Amy Simonne,

Murat Balaban, Maurice R. Marshall, Stephen T.

Talcott and Mathew Lecky).

Materials & Methods

Supercritical CO2 Extraction of Tomato:An initial run of the supercritical CO

2 extrac-

tion unit (Picture Plate I- 1) was completed in mid

July 2002 after a pump (see Picture Plate I-2) was

purchased and installed. For each run, two kilograms

(5 pounds) of tomato were sliced into pieces (Pic-

ture Plate I-4,5) and were dried to about 50% of the

original moisture in a vacuum oven. The semi-dried

samples (Picture Plate I-6) were then placed in a

thimble (Picture Plate I-8) and placed in the sample

chamber (Picture Plate I-3). Typical extraction time

range from 4-6 hours. Because tomato is high in

moisture (>90%), one of the most critical steps in

the extraction process is the moisture reduction step

or drying. We examined the distribution of tissues

in marketable tomatoes obtained from the market for

the initial run and found that the outer, inner tissues

and tissues in the fruit cavities to be 57.7%. 19.12%

and 23.2% of the total fruit weight, respectively (Pic-

ture Plate I-10). This preliminary data suggested that

one of the major steps to eliminate moisture is to

eliminate liquid in the fruit cavity. Other factors af-

fecting extraction efficiency and recovery of lyco-

pene from tomato include temperature, CO2 flow rate,

pressures, and presence of other co-solvents. Ma-

nipulation of tomato such as drying (with or without

CO2) or freeze-drying to improve extraction effi-

ciency will be evaluated as it is known that some

drying will help in the handling and extraction. How-

ever, it must be assured that drying does not oxidize

the lycopene. We will continue to explore quality of

dried tomato products before CO2 critical fluid ex-

traction to see their potentials as novel functional food

ingredients. Because of a delay in funding, we will

evaluate the vine ripe cull tomatoes (from pin-hooker)

later this Fall.

Lycopene Determination in Tomato by HPLC:Because lycopene and other carotenoids in

tomato are unstable due to heat, light, air, and acid-

ity, these factors will be additionally evaluated. Ly-

copene stability and efficiency of the extraction pro-

cess will be monitored by HPLC methods described

by Simonne et al. (2001; 2002). Figures 1 and 2 show

some sample chromatograms of lycopene and other

carotenoids in tomato tissues (outer and inner tissues

and whole tomato). Carotenoid profiles for outer and

inner tissues as well as the whole tomato tissue are

similar, despite the difference in quantity. It appeared

that outer tissues contained higher lycopene than in-

ner tissues. Although lycopene is a major carotenoid

in tomato, lutein and beta-carotene are also present

in significant amounts in this tomato variety. This

finding will facilitate us in selecting tissues for the

CO2 extraction.

Objective 2To identify post-harvest handling procedures

which promote rapid carotenoid (primarily lycopene)

biosynthesis and other phenolic phytochemicals in

fresh-market cull tomatoes (Bala Rathinasabapathi,

Stephen T. Talcott, Steven A. Sargent, Jeff Brecht,

Abbie J. Fox, and Celia Sigua).

Materials & Methods

Post Harvest treatment of Cull Tomatoes:Tomatoes (‘FL 47’) were harvested on May

8, 2002, from a packinghouse in Palmetto. They were

run through the grading line and culled tomatoes were

collected directly from the cull conveyor. Three

samples were collected over a 30-minute period, with

two standard cartons representing one sample, and

these were brought to the Postharvest Horticulture

Laboratory in Gainesville.

The same day, the tomatoes were first classi-

fied into two groups, usable and unusable. Each group

was then classified by defect classification and color

stage. Subjective ratings were employed to rate to-

mato ripeness at harvest and during the storage pe-

riod according to U.S.D.A. grade standards for fresh

tomatoes. (See Tables 1, 2, 3).

Defect classifications were defined as follows (See

Picture Plate 2):

85

Usable: - slight cat-face and/or zipper, misshapen,

minor cuts, minor growth cracks and sound

(no defects).

Unusable - decay, severe cut (exposed internal tis-

sue), over-ripe (soft), undersize (immature),

insect damage and severe cat-face.

After sorting the greens from the ripenened

fruit, they were then sorted by defect category (cut,

growth crack, catface, and sound) and placed into

foam-cell trays. The green tomatoes were placed in

a flow-through chamber and exposed to 100 ppm hu-

midified ethylene; pink tomatoes were also placed

in a flow-through chamber but only exposed to hu-

midified air. The tomatoes were observed after 5 and

10 days storage at 68 EF for incidence of decay and

ripening rate (see Picture Plate 2).

Screening of lycopene levels bySpectrophotometry:

Culled tomatoes of cultivar FL-47 were

manually sorted into diseased, cut, catface, and

cracked, based on the defects found on the fruit. The

defects are illustrated in Picture Plate 2. Diseased

fruit were discarded. Some of the fruit that did not

have any of these defects were categorized as sound.

Stage 4 fruit, identified by the development of some

red color, in each defect category were incubated for

10 days at 20oC and stage 1 green fruits were treated

with 100 ppm ethylene at 20 EC for 10 days. At the

end of these treatments, color development was as-

sessed using a Minolta colorimeter.

Fruit in each category were sliced and separated into

“outer tissue” and “all other tissue” (all the interior

tissue), and pureed in a blender. A known volume of

water was added to puree the outer pericarp tissue.

Lycopene was extracted in a mixture of solvents (0.1

g puree, 2.5 mL acetone, 2.5 mL ethanol, and 5 mL

hexane) containing 0.05% (w/v) BHT (Perkins-

Veazie et al., 2001). Water (1.5 mL) was added to

separate the hexane fraction. Lycopene in hexane

was quantified using an UV-Visible spectrophotom-

eter (DU520, Beckman Instruments) at 444 nm, and

comparing to a standard curve made with pure lyco-

pene (Sigma Chemical Company, L9879). A scan of

the hexane fraction of the extracts closely resembled

that of the standard lycopene (Figure 3).

Each treatment (category of fruit, air or eth-

ylene) contained more than 10 fruit. Six fruit were

randomly chosen for lycopene extractions. For mea-

surements of weight, volume, and lycopene content,

two fruit were pooled together and triplicate values

were obtained. The data were analyzed using Analy-

sis of Variance (SAS statistical package). Duncan’s

multiple range test was applied for mean separation

at P=0.05.

Results and DiscussionResults of our study are presented in Table 5.

Our data indicate:

1. abThe fruit wall (pericarp), which contrib-

uted to 10 to 15% of the total fruit fresh

weight had significantly more lycopene per

g fresh weight than the rest of fruit tissue

(locular tissue).

2. abThe pericarp tissue of cracked tomatoes

receiving no ethylene treatment and sound

tomatoes receiving ethylene treatment had

the highest levels of lycopene (306 mg and

216 mg per g tissue). The locular tissue of

these fruit had about 1/3 less lycopene (89

and 86 mg per g tissue).

3. abSound fruit responded to ethylene treat-

ment by producing about 2-fold more

lycopene both in the pericarp and the

locular tissue (216 mg per g vs 105 mg per

g in the pericarp and 89 vs. 38 mg per g in

the locular tissue).

4. abMean lycopene levels in the pericarp of

fruit with cuts, catface, and cracks, and the

interior tissues of those with cuts, catface,

and cracks did not increase significantly or

increased only marginally in response to

ethylene treatment.

The conclusion was thatd many defects iden-

tified in culled tomatoes of cultivar FL-47 caused no

problems for lycopene development and extraction.

A standard ethylene treatment could improve color

development in certain categories of fruit but not oth-

ers. The results observed here will be verified using

culled fruit of the same variety harvested in a differ-

ent season.

Lycopene level per unit tissue weight is higher

in the outer pericarp compared to the interior tissues.

86

Hence, it will be useful to test whether separation of

the pericarp tissue from the rest of the tissues is of

any advantage for large scale isolation of lycopene

by supercritical CO2 extraction.

Non-Carotenoid PhytonutrientsTissue was blended in a Brinkman homog-

enizer to the smallest attainable particle size prior to

analysis. Polyphenolic analyses were conducted on

an aqueous extract following centrifugation using the

Folin-Ciocalteu for total gallic acid reducing equiva-

lents (Swain and Hillis, 1959) and also separated by

HPLC using the method of Talcott and Howard

(2000) against standards of p-hydroxybenzoic acid,

caffeic acid, and quercetin. Antioxidant capacity was

conducted using the ORAC assay of Ou (2002)

against a standard of Trolox, a synthetic, water-

soluble analog of vitamin E. Carotenoids were ex-

tracted from the original homogenate using hexane

containing 0.2% BHT as a preservative. Organic ex-

tracts were quantified by HPLC according to Howard

et al.(2000) and confirmed via spectrophotometric

readings at 444, 470, and 502 nm.

ResultsTreatments affecting biosynthetic rates of

phytochemicals are often quantified via non-

carotenoid phytochemicals, since these compounds

generally respond quickly to changing environ-

mental conditions. By measuring total reducing

compounds (total soluble phenolics) and those

compounds that are able to inhibit a specific

radical (peroxyl), an overall assessment of treat-

ment efficacy was obtained. No difference in

phytochemical concentrations or antioxidant

capacity was found due to ethylene exposure, and

no appreciable difference was found due to

preharvest selection of fruit (Table 6.). However,

outer tissue layers generally had higher levels of

total soluble phenolics (Folins) and flavonoid

glycosides that related to higher ORAC values.

Levels of hydroxybenzoic and hydroxycinnamic

acids were not different between tissues (Table 6.).

Antioxidant activity measured by the ORAC assay

factors on primarily polar antioxidants; therefore

contributions from lycopene were not correlated to

antioxidant capacity. However, more lycopene was

present in outer skin layers as opposed to inner

layers, which is apparent from visual observations.

Total phenolics and total flavonoid concentrations

were significantly correlated to ORAC values

(r=0.94 and 0.67, respectively) indicating their role

in antioxidant protection for the fruit, localized

where lycopene was most prevalent (outer tissue

layers). Lycopene concentrations were also corre-

lated to spectrophotometric readings at three

wavelengths (r>0.94) and along with good correla-

tions to antioxidant capacity these rapid assays

proved to be sufficient for phytochemical assess-

ment of tomatoes.

87

References

Howard, L R, Talcott, S T, Brenes, C H and

Villalon, B 2000. Changes in phytochemi-

cal and antioxidant activity of selected

pepper cultivars (Capsicum Species) as

influenced by maturity. J. Agric. Food

Chem. (48):1713-1720.

Ou, B, Hampsch-Woodill, M, Prior, RL 2001.

Development and validation of an im-

proved oxygen radical absorbance capacity

assay using fluorescein as the fluorescent

probe. J. Agric. Food Chem. (49):4619-

4626.

Perkin-Veazie, P, Collins JK, Pair SD, Roberts, W.

2001 Lycopene content differs among red-

fleshed watermelon cultivars. J Sci Food

Agric. (81):983-987.

Simonne, A, Simonne, E, and Eitenmiller, R. 2002.

Bitterness and chemical composition in

lettuce grown in the Southeast United

States. HortTechnol. (In press).

Simonne, A, Huang, T and Wei, CI. 2001. Cooking

time unequally affects carotenoids in

different vegetables. Paper presented at the

national IFT meeting in NewOrlean, June

23-27, 2001.

Swain, T, Hillis, WE 1959. The phenolic constitu-

ents of Prunus domestica. I. The quantita-

tive analysis of phenolic constituents. J.

Sci. Food Agric. (10): 63-68.

Talcott, S T, Howard, LR, Brenes, CH 2000.

Antioxidant changes and sensory properties

of carrot puree processed with and without

periderm tissue. J. Agric. Food Chem.

(48):1315-1321.

88

89

90

91

92

93

94

95

Figure 3. A Scan of tomato outer tissue extract (A) compared to lycopene standard (B).

96

Sanitation to eliminate hazardousmicroorganisms from tomato fruit

Jerry Bartz1, Keith Schneider2, Kelly Felky2,

and Steve Sargent3. 1Plant Pathology,2Food

Science and Human Nutrition, and 3Horticultural

Sciences Department, University of Florida, IFAS,

Gainesville.

AbstractWater sanitation procedures were examined

to determine how to kill Salmonella spp. that might

be deposited on tomatoes by field crews, various

wild or domestic animals or through wind-blown

rainfall. Dried deposits were successfully inacti-

vated by a 2 min treatment with 150 ppm free

chlorine at pH 6.5 and 35 or 45oC. A portion of the

deposits were washed from the fruit by the action

of the scale model flume and were found to con-

taminate nearby clean fruit. The presence of the

chlorine in the water prevented this dispersal.

However, bacteria deposited in shaved wounds, the

stem scar or surface punctures were not inactivated

by the chlorine. Chlorine alternatives were tested

for cleaning fruit. Acidified sodium chlorite,

hydrogen peroxide, chlorine dioxide and peroxy-

acetic acid equaled or exceeded chlorine in effi-

cacy. However, price, odor control, efficacy

against decay pathogens, and worker safety issues

have not been fully explored.

Proposal and objectivesTwo potential microbial hazards have been

associated with fresh market tomatoes sold in the

U.S.A. Direct losses due to postharvest decays

have been associated with the inoculation of

tomatoes by plant pathogens during postharvest

handling (Bartz, 1980, Ceponis et al., 1986),

whereas indirect losses have been associated with

the contamination of tomatoes by certain human

pathogens. Primarily due to weather conditions,

occasional outbreaks of postharvest decays accom-

pany field production of tomatoes. While

postharvest decay losses are uncommon, they are

not unusual, particularly during rainy periods. A

theoretical, but greater risk involves the contami-

nation of fruit by enteric pathogens of humans.

Although bacteria responsible for food-borne

illnesses have never been directly isolated from

Florida-grown tomatoes, a trace back analysis in

2000 implicated Florida tomatoes in a outbreak of

salmonellosis associated with a fast-food chain.

Given the number of boxes of tomatoes

shipped out of Florida over the years and the

absence food-borne illness outbreaks actually

traced to those tomatoes, one could conclude the

risk of contamination is non-existent. However, as

noted above, Florida tomatoes were suspected of

being involved in one outbreak. Effective hazard

control dictates that food industries do everything

possible to produce a wholesome product and this

fact must be communicated to consumers (Powell,

2001).

Our objectives in this proposal were to

determine the chlorine concentration, solution pH

and water temperature needed to:

(i) disinfect organic deposits as they

are washed from fruit surfaces;

(ii) prevent the accumulation of human

pathogens in dump tanks and

flumes;

(iii) prevent dispersal of human patho-

gens among tomatoes in a flume;

(iv) disinfect areas on fruit that were in

contact with contaminants;

(v) control microorganisms on surfaces

that contact fruit during harvest and

handling such as picking containers,

field bins, and packing lines.

The soft rot bacterium, Erwinia carotovora,

will be used as a surrogate for human pathogens to

determine effective chlorine treatments for pre-

venting contamination and eliminating contami-

nants. The effectiveness of the final treatments

will be validated in tests with a five-strain cocktail

of Salmonella spp.

AchievementsA graduate student whose assistantship was

covered through a tri-state food safety grant en-

abled us to immediately conduct experiments with

the five-strain cocktail of Salmonella spp

Five serovars of Salmonella, S. agona, S.

gaminara, S. michigan, S. montevideo, and S.

Poona, were kindly provided by Dr. Linda J.

Harris, U. Ca., Davis. Rifampicin resistance was

97

induced in the strains to allow easier recovery of

Salmonella from treated fruit. Maintenance of the

cultures and production of inoculum followed

standard microbiological procedures. For produc-

tion of inocula, cultures were grown in liquid

culture, removed by centrifugation and washed

twice with phosphate buffer saline (PBS) (Sigma-

Aldrich, St. Louis, MO) to eliminate substances

that would react with the test sanitizers. All five

strains were combined as a cocktail and diluted in

phosphate buffered saline (PBS).

Ten 10 _L- samples of the bacterial suspen-

sion were spotted at separate locations on blemish

free portions of the fruit surface for a total of 1.0 x

108 CFU/tomato. The spots were allowed to dry

for 1 h before treatment. In subsequent tests,

various types of wounds and the stem scar were

inoculated with the Salmonella cocktail. The dried

bacterial deposits simulated organic debris in

objective no. 1.

Chlorine stock solutions were prepared

from a sodium hypochlorite concentrate, diluted to

50, 100, or 150 ppm with phosphate buffer and

adjusted to pH 6.5, 7.5, and 8.5. The free chlorine

concentration was verified using methods ap-

proved by the U.S. Environmental Protection

Agency.

Whole pink or green tomatoes inoculated

and dried as above were placed in a circulating

water bath. Water temperatures were adjusted to

25, 35, or 45°C depending on the test. The circu-

lating water bath simulated a flume as found in

tomato packinghouses. Tomatoes were removed at

15, 30, 60 or 120 seconds after being placed in the

bath. The bacteria on the tomatoes were recovered

by standard methods. The water in the bath was

tested for viable bacteria as well.

After determining the most effective pH

with 50 ppm free chlorine, we examined the

efficacy of 100 and 150-ppm chlorine at solution

temperatures of 25, 35, or 45oC (77, 95 or 113oF,

respectively). Tomatoes with various wounds

(puncture, shaved area or stem scar) were inocu-

lated as above and treated with 150-ppm chlorine

at pH 6.5 and 45oC as described in tests on surface

populations.

Aqueous solutions of alternative sanitizers

were prepared at maximum allowable concentra-

tions and used to treat inoculated tomatoes for up

to 2 min. Surviving populations of Salmonella

were then recovered from the treated tomatoes as

described for tests with chlorinated water.

Based on the literature and popular recom-

mendations, 50 ppm free chlorine is more than 50

times more concentrated than the amount required

to kill suspended cells of Salmonella within 2 min.

However, when cells are allowed to dry on depos-

its on tomato fruit, they are clearly more difficult

to kill. A few bacteria on the fruit survived expo-

sure to 50 ppm free chlorine for 2 min (Fig. 1)

98

Salmonella were not detected in the flume water,

evidence that bacteria washed from the fruit were

killed immediately. This precluded an accumula-

tion in the water. The 50-ppm solution was

slightly more effective at pH 6.5 than at 7.5 or 8.5.

This is consistent with the literature on the species

of chlorine in solution and the solution pH (White,

1999). Hypochlorous acid predominates over

hypochlorite ion at pH levels less than 7.5. Hy-

pochlorous acid is between 20 and 300 times more

effective in killing various bacteria than is hy-

pochlorite ion.

When fruit are dumped into a simulated

water flume containing plain water, populations of

Salmonella on the fruit decrease by 1 to 2 logs

within 2 min (Water Rinse line, Fig. 2.)

This represents suspension in the water of about 9

X 105 cfu per fruit. Although 90 to 99 % of the

bacteria were removed from the fruit surface just

by action of the moving water, a substantial num-

ber remained. When clean fruit were placed

together with the contaminated fruit, the clean fruit

picked up nearly 103 Salmonella per fruit, evidence

that cross contamination will occur if the flume

does not contain an effective sanitizer such as

chlorine. The bacteria suspended in the water also

will likely contaminate equipment down stream

from the flume and ultimately, the entire

packingline will be a source for contamination of

the tomatoes that are being packed. The Salmo-

nella cocktail was killed more rapidly at 150 as

compared with 100 or 50 ppm, particularly with

shorter exposure intervals. Complete elimination

of Salmonella from the fruit surface occurred only

with the 150-ppm concentration, but required the

full 2-min exposure.

The chlorine solutions warmed to 35 or 45 C were

more effective than the 25-C solution although

there was no statistical difference in efficacy

between the 35 or 45 C solutions.

99

When wounds (punctured, shaved or stem

scar) were inoculated with the Salmonella cocktail,

treatment with 150 ppm chlorine at pH 6.5 and

45oC had little effect on populations in the wound.

This is consistent with the literature. Wei et al.

(1995) and Zhuang et al. (1995) both reported that

Salmonella suspensions placed on the stem scar

region of tomatoes were not inactivated (decreased

by up to 99 but not 100%) by subsequent exposure

to 100 or up to 320 ppm chlorine, respectively for

2 min.

Although chlorinated water does not disin-

fect various wounds on tomatoes that have been

contaminated with Salmonella or other hazardous

microorganisms, which includes decay pathogens,

it can inactivate deposits on the skin and prevent

accumulations in the water of dump tanks, flumes

or washers. By inactivating skin deposits and

preventing water accumulations, proper water

chlorination minimizes microbial hazards in fresh

market tomatoes. Proper water chlorination is

defined as maintaining at least 150 to 200 ppm free

chlorine in water at a pH of 6.0 to 7.5 and a tem-

perature of 35 to 45oC. The tomatoes should have

a residence time of at least 1 min. The free chlo-

rine concentration should be measured frequently

since the chemical reacts rapidly with tomato

surfaces as well as various materials accompanying

the fruits when they are dumped into the packing-

house water system. Alternatively, an oxidation-

reduction potential (ORP) system can be installed,

which automatically maintains a set ORP. The set

ORP should be determined prior to the addition of

tomatoes when the system has been filled, warmed

and chlorinated to the desired range.

Discussions were made with several manu-

facturers of instruments to measure water sanita-

tion. The sensors employed are designed for use in

clean water systems or systems with suspended

particulate matter, such as swimming pools, sew-

age treatment plants, etc. They become quickly

fouled out when used in water containing irregular

suspended solids, such as dump tank water. The

response time of these sensors is somewhat slow,

more than 1 minute. In-line colorimetric analyzers

are also designed for clean water systems and these

are limited to measuring free chlorine below 5

ppm. Therefore, for now, the best option appears to

be correlating ORP with free chlorine.

There are currently no calibration systems

available for pH/ORP control systems. There is

potential to develop a stand-alone, automated

calibration system that could be added to an exist-

ing pH/ORP system. The key to a reliable calibra-

tion system would be to have a standard solution

that would remain stable over time for periodic use

during calibration. To find if dilute chlorine

solutions were stable, we prepared a standard

solution in the laboratory according to UF/IFAS

recommendations. About 100 ppm free chlorine

was added to 1 liter of deionized water and then

adjusted to pH 7.0. This solution was held at about

74 oF, shielded from light and sealed with a stop-

100

per. Over a period of 14 days the solution pH

and concentration of free chlorine remained

stable as measured by a digital pH meter, digital

ORP meter and Hach colorimetric free-chlorine

test. One company, Analytical Technologies,

Inc., a manufacturer of sensors, has indicated

interest in working with Florida packer/shippers

in designing a prototype automated calibration

unit. This will be explored in the upcoming year.

The “proper water chlorination” de-

scribed above will also prevent the accumulation

of bacterial and fungal decay pathogens and will

prevent fruit from becoming inoculated in the

flume (Bartz et al., 2001). Both the pH range

and the solution temperature are critical compo-

nents of proper water chlorination. Higher pH

solutions do not have more stability in the tank

than to those in the 6.0 to 7.5 range, but are

slower acting (Bartz, unpublished).

Acidified sodium chlorite (1200 ppm),

hydrogen peroxide (5%), and peroxyacetic acid

(80 ppm) were more effective in removing

Salmonella from fruit surfaces than was 150

ppm chlorine at pH 6.5. These chemicals will

next be tested for efficacy against fungal decay

pathogens. Also, relative price and odor issues

will be explored. Chlorine dioxide (5 ppm) was

about equal to chlorine in efficacy. However,

use of this chemical at 5 ppm in an open dump

tank, flume, and then washer water system is

known to have odor and safety issues. Ozone at

1.3 ppm was not as effective as chlorine, was

difficult to create due to instability and like

chlorine dioxide would have odor and safety

issues. Two other alternatives for water sanita-

tion, UV light and copper ion, were not tested.

UV light would not produce a germicidal at the

initial fruit contact with water. Copper ion,

while effective in clean swimming pools, would

not kill bacteria within seconds of contact.

Bartz, et al. (2001) and Johnson (1945) noted

that bacteria and water soluble dyes moved into

wounds and water congested natural openings in

plant tissues instantaneously apparently through

capillary forces. These observations explain

why 150 ppm chlorine does not disinfect con-

taminated wounds (the bacteria become deeply

embedded in the wound) and also why Salmo-

nella on tomatoes have to be killed within seconds

of contact with the water.

Literature Cited

Bartz, J. A. 1980. Causes of postharvest losses in

Florida tomato shipments. Plant Dis. 64:934-

937.

Bartz, J. A., Eayre, C. G., Mahovic, M. J.,

Concelmo, D. E., Brecht, J. K., and Sargent,

S. A. 2001. Chlorine concentration and the

inoculation of tomato fruit in packinghouse

dump tanks. Plant Dis. 85:885-889.

Bartz, J. A., Mahovic, M, and Concelmo, D. 2001.

Rapid movement of inoculum into wounds

on tomato fruit. (abstr). Phytopathology

91:S6.

Ceponis, M. J., Cappellini, R. A., and Lightner, G.

W. 1986. Disorders in tomato shipments to

the New York market, 1972-1984. Plant Dis.

70:261-265.

Dychdala, G. R. 1991. Chlorine and chlorine

compounds. p. 131-150. In: S. S. Block

(ed.). Disinfection, sterilization, and preser-

vation. Lea & Febriger, Philadelphia.

Johnson, J. Infection experiments with detached

water-congested leaves. Phytopathology

35:1017-1028.

Powell, D. A., 2001. Food safety and the consumer

– Perils of poor risk communication. Can. J.

An. Sci. 80(3 ): 393-404.

Sherman, M., Showalter, R. K., Bartz, J. A., and

Simone, G. W. 1981. Tomato packinghouse

dump tank sanitation. Veg. Crops Fact Sheet

VC-31, Fla. Coop. Ext. Serv. Univ. Fla. Inst.

Food Agric. Sci. Gainesville, 4 p.

Wei, C. I., Huang, T. S., Kim, J. M., Lin, W. F.,

Tamplin, M. L., and Bartz, J. A. 1995.

Growth and survival of Salmonella

montevideo on tomatoes and disinfection

with chlorinated water. J. Food Prot.

58:829-836.

White, G. C. 1999. Handbook of Chlorination and

Alternative Disinfectants. 4th. ed. Van

Nostrand Reinhold, New York.

Zhuang, R.-Y., Beuchat, L. R., and Angulo, F. J.

1995. Fate of Salmonella montevideo on

and in raw tomatoes as affected by tempera-

ture and treatment with chlorine. Appl.

Environ. Micro. 61:2127-2131

101

Competition in the Winter FreshTomato Market

John J. VanSickle, Director

International Agricultural Trade and Policy Center

Food & Resource Economics Department, IFAS

University of Florida

Gainesville, FL 32611-0240

AbstractCompetition in the U.S. winter fresh tomato

industry continues to be intense and it is critical for

Florida growers to monitor the situation within this

market. Analyses of costs of producing fresh

tomatoes in Mexico indicates that costs have

increased significantly over the last 7 years and

that the advantage once derived from the devalua-

tion of the peso has disappeared. While costs of

producing and exporting tomatoes to the U.S.

market fell from $7.52 per 25 pound carton equiva-

lent in the 1990/91 season to $5.31 per carton in

the 1994/95 season, inflation has since caused

those costs to increase to $7.35 per carton in the

2000/01 season. The Florida industry also has been

aggressive in their education and promotion pro-

grams to increase the demand for Florida fresh

tomatoes. An evaluation of those expenditures

indicates that growers have realized a return of

6.25 percent on that investment, with added profits

of $20.67 million in their operations.

IntroductionThe winter fresh tomato industry has

witnessed several changes over the last several

years, beginning with increased competition from

Mexico, the entrance of greenhouse grown toma-

toes and the resulting trade disputes that followed

this increase in competition. Competition must be

monitored and the Florida industry must manage

their resources to give them the best opportunity to

compete in this marketplace.

As part of this project several products

have been developed to help the Florida tomato

industry. An evaluation of the education and

promotion program was completed in December,

2001, as part of the requirement to conduct these

activities as part of the Federal Marketing Order

(VanSickle and Evans, 2001). The results of that

analysis indicated that growers were benefiting

from the education and promotion programs being

funded by the marketing order. The average return

to investment in education and promotion activities

was estimated to be 6.25% with Florida growers

adding $20.67 million in profits to their operations

from these activities.

This project also contributed to the infor-

mation that was required for the trade dispute filed

against Canadian greenhouse tomato growers. One

of the key issues in that case involved determining

the ‘like product’ for calculating injury. A test was

proposed for this issue that was not accepted by the

International Trade Commission, but a publication

is being prepared for review within the scientific

community that may help in defining the means for

testing for ‘like product’ (Evans et al., 2002).

This project also contributes to the knowl-

edge necessary for assessing competition with

Mexico by providing updates on the costs of

producing tomatoes in Sinaloa, Mexico, and

exporting those tomatoes to the U.S. market. The

results of that analysis indicates that costs in

Mexico have increased relative to Florida as

inflation has increased more than in the U.S. since

1994/95. Costs in Mexico were lowest in the 1994/

95 season with a delivered in cost of $5.31 per

carton. Costs have increased since then to $7.35

per carton in the 2000/01 season. A discussion on

this analysis follows.

Methodology used to estimate costsin Mexico

The budgets developed for Mexican grown

tomatoes are based off of estimations by VanSickle

et al. (1994) made for the 1990/91 crop year and

on budgets published by the Confederacion de

Asociaciones Agricolas Del Estado de Sinaloa

(CAADES). CAADES is the umbrella organization

for grower organizations organized in the state of

Sinaloa, Mexico. The VanSickle et el.report was

completed as an assessment of competition in the

U.S. market for fresh winter vegetables. The

CAADES reports are published annually from

information supplied by growers to CAADES.

The baseline numbers for 1990/91 are taken

directly from VanSickle et al. and converted into

total costs in pesos per hectare of production. The

102

preharvest costs reported by VanSickle et al. were

reported in dollars per acre. Those numbers were

converted to pesos per hectare by multiplying the

numbers by 2.471 to get the hectare equivalent and

then multiplying by 2950 to get the peso equivalent

cost. The harvest and post harvest expenses re-

ported by VanSickle et al were on a per unit cost

basis. Those costs were converted to a per acre

equivalent by first multiplying the per unit cost by

the exchange rate of 2.95 to get the peso equivalent

cost. The harvest and haul and packing costs were

then multiplied by the total per hectare yield of

2,718 cartons to get the total cost in pesos for

harvest and haul and packing charges on a per

hectare basis for 1990/91. The per unit marketing

charges for transport to the border, tariff, other

crossing fees and selling cost were multiplied by

the exchange rate in 1990-91 of 2.95 and then by

the export market yield of 2174 to get the per

hectare peso cost of these items.

1994/95:The 1990/91 preharvest cost items of land

rent, labor, machinery and misc/overhead were

adjusted by the change in the producer price index

of intermediate materials for preparation of fruits

and legumes (Banco de Mexico, 2002) from

September, 1990, to September, 1994, (1.42) for

the 1994-95 season. The 1990/91 preharvest cost

items of transplants, fertilizers and pesticides were

adjusted according to the changes recorded in the

CAADES budgets from 1990/91 to 1994/95.

Changes in these costs capture much of the tech-

nological change in tomato production relative to

other items.

The interest rate expense was calculated by

summing all other preharvest costs and then apply-

ing the interest rate reported as the money market

representative interest rate (Banco de Mexico,

2002) of 24.73% for 55 days, the same method as

applied by VanSickle et al..

The 1990/91 harvest and post harvest

expenses of harvest and haul and packing were

adjusted by multiplying the 1990/91 per unit costs

reported in dollars/carton by the January 1991

exchange rate of 2.95 and then by the change in the

producer price index of intermediate materials for

preparation of fruits and legumes from January,

1991 to January, 1995(1.50) to account for infla-

tion. That product was then multiplied by the total

yield for 1994/95 of 3843 to get the cost in pesos

per hectare. The total yield was derived from the

CAADES reported export yield of 3074 which was

divided by .8 to get the total yield.

The 1990/91 marketing expenses for

transport to the border and other crossing fees were

adjusted by multiplying the total cost calculated for

1990/91 by the change in the producer price index

of intermediate materials for preparation of fruits

and legumes for Mexico from January, 1991, to

January, 1995 (1.50).

The tariff cost was calculated by using the

per unit weighted average tariff rate reported by

VanSickle et al. (0.46) discounted 20% to account

for lower tariffs resulting from NAFTA and multi-

plying it by the January, 1995 exchange rate of

5.6405. That product was then multiplied by the

export yield of 3074 to derive the per hectare cost

of the tariff.

Selling costs for 1994/95 were calculated

by using the baseline total costs calculated for

1990/91 and adjusting those for the increase in

export yield (3074 reported in 1994/95 compared

to 2174 reported in 1990/91) and for the change in

unit value as reported by the U.S. Department of

Commerce (DOC) import statistics ($706.73 per

metric ton in 1990-91 compared to $684.72 in

1994/95). The average unit values were calculated

using monthly imports and average values for the

January to May periods in 1991 and 1995 as

reported by DOC.

1995/96 and following seasons:Adjustments for 1995/96 and following

seasons were made following the same procedures

as used for 1994/95. The inflation factor was

highest in the 1995/96 season following the large

devaluation in the peso from 1994 through 1996.

The pre-harvest costs inflation factor was 1.49 in

the 1995/96 season and the post-harvest costs

inflation factor was 1.52. The last reported yield

increase occurred in the 1995/96 season with a

reported export yield was 4500 and the total yield

was 5625. The interest rate used in interest cost

calculations peaked in 1995/96 at 42.35%, but

declined to 16.5% in the 2000/01 season. The tariff

103

rate was discounted an additional 10% for each

season to account for NAFTA reductions with the

tariff scheduled for elimination in January 2003.

ResultsThe results of these analyses indicate that

total costs for exporting tomatoes to the U.S. from

Mexico reached their lowest level in 1994/95

following the large devaluation in the peso that

occurred over that period. Since then inflation has

occurred to offset that cost reduction and per unit

costs are only slightly lower than the cost reported

in 1990/91. Clearly the advantage that was af-

forded Mexico from the devaluation of the peso

has been offset by inflation and technology devel-

opment relative to technology in Florida will be the

deciding factor on competitiveness between these

two areas.

References

Banco de Mexico. 2002. www.banxico.org.mx

Evans, Edward, Jione Jung, John J.VanSickle, and

Robert Emerson. 2002. “A Test to Deter-

mine Like Products: The Case of Green-

house Tomatoes.” Working paper.

VanSickle, John J., Emil Belibasis, Dan Cantliffe,

Gary Thompson and Norm Oebker. 1994.

“Competition in the U.S. Winter Fresh

Vegetable Industry.” USDA ERS AER 691.

VanSickle, John J. and Edward Evans. 2001. “The

Florida Tomato Committee’s Education and

Promotion Program: An Evaluation.” Paper

submitted to USDA AMS by the Florida

Tomato Committee.

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