I I l Vegetarian Newsletter
A Vegetable Crops Extension Publication University of Florida
Vegetarian 02-01 Institute of Food and Agricultural Sciences
January 2002 Cooperative Extension Service
(Note: Anyone is free to use the information in this newsletter. Whenever possible, please give credit to the authors.
The purpose of trade names in this publication is solely for the purpose of providing information and does not
necessarily constitute a recommendation of the product.)
A Print Version
Reducing Mechanical Damage During Transplant Digging Increases Early
Season Fruit Yiled of Strawberry
0 Biologically-based Disease Management Products in Florida Vegetable Production
0 Vegetable Postharvest Information on The Internet
0 No article this month
List of Extension Vegetable Crops Specialists
I Evets Ca
Commercliai]I][1Wle[1 Veget[bl Prduction4 '
20-002 Posth aryvest Ho.rt-icu.ture .l.ndustry Tour March 4-7, 2002. Visit postharvest
operations from harvest through shipping in central and southwest Florida. Special rates are available
for county and statewide faculty. Contact Steve Sargent (firstname.lastname@example.org, 352-392-1928, ext.
215) or Mark Ritenour (email@example.com, 561-467-3877).
I Reducing Mechanical Damage During Transplant Digging Increases
Early Season Fruit Yiled of Strawberry
Commercial strawberries are propagated asexually by producing daughter plants on stolons originating from a
mother plant. Bare root transplants are produced in open fields, where daughter plants remain attached to the mother
plant and are allowed to root into the soil. According to Latimer (1998) the goal of transplant production is to produce
plants which: 1) withstand the stress of handling, transportation and transplanting, 2) adapt rapidly to the field
environment, 3) establish and resume active growth soon after transplanting and 4) produce acceptable yields
without reduction or delay compared to other establishment methods. Water management (Leskovar, 1998),
pre-transplant nutrition (Dufault, 1998), transplant size (NeSmith and Duval, 1998; Latimer 1998), transplant age
(Vavrina, 1998) and transplant root structure (Nicola, 1998) may all be contributing factors to a strawberry plant's
success in the fruiting field.
To supply the demand for plants in Florida, most bare-rooted green-top transplants for winter production are
mechanically harvested using modified potato digging equipment, in high latitude (> 420) or high altitude nurseries.
A typical harvest operation involves the following procedures; plants are 1) removed from the soil using digging
equipment, 2) placed in large bins using pitchforks, 3) transferred to a packing facility, 4) separated from each other
by hand, 5) counted and placed in plastic lined boxes (400 to 600 plants per box) and 6) pre cooled and shipped to
Florida in refrigerated trucks. During harvesting and packing operations, transplant petioles, leaves and crowns may
be crushed and/or broken. Damaged plants are likely to take longer to resume normal growth after establishment in
the fruiting field. High demand for fruit in late fall and early winter creates a lucrative market for Florida strawberry
producers. A plant which resumes growth quickly and produces more fruit early in the season is highly desirable for
Florida strawberry growers. Earlier plantings are not feasible due to the transplants need to be exposed to chilling
and short day lengths in the nursery to initiate flowering in the fruiting field. Therefore, it is essential to produce
transplants that will rapidly resume growth in the fruiting field. The influence of transplant digging and packing
operations on subsequent strawberry fruit yield has not been determined. The purpose of this study was to compare
the performance of hand and machine dug transplants in the fruiting field.
Material and Methods
Transplants of 'Sweet Charlie' and 'Camarosa' were randomly selected from plants that were dug and packed using
standard mechanized harvesting and packing practices in a commercial transplant producer's field in Nova Scotia,
Canada. On the same day, additional plants, from the same field, were carefully dug and packed entirely by hand,
minimizing all potential damage during transplant harvest and packing operations. Soil was removed from the roots of
all transplants. Transplants were shipped in the same container to the Gulf Coast Research and Education Center,
Dover, Fla. (GCREC-Dover). Transplants were set 2 Nov.1999 and 10 Oct. 2000 on black plastic mulch in the annual
hill cultural system. Cultivar and digging method were arranged in a 2 X 2 factorial design replicated four times with
16 plants per treatment. Overhead irrigation was used for 10 hours/day for 10 days to establish transplants. All other
irrigation was through drip tape placed underneath the polyethylene mulch. Frost protection, by overhead impact
sprinkler irrigation, was applied six times during the 2000-2001 season. Plant fertilization and pest control were
maintained in accordance with University of Florida extension service recommendations (Maynard and Olson, 2000).
Fruit were harvested twice weekly beginning on 5 Jan. 2000, and 15 Dec. 2000 for the 1999-2000 and 2000-2001
season respectively. All harvested fruit were graded for marketable weight, marketable number and cull fruit (number
of small (< 10g), misshapen and diseased fruit). Data were organized monthly and seasonally and analyzed by
analysis of variance using SAS statistical software (SAS Institute, Cary NC).
Results and Discussion
Monthly and seasonal marketable yields for strawberry production in the 1999-2000 season revealed significant
treatment differences for digging technique and cultivar, and a significant interaction of the two in January and March
of 2000 (Table 1). Marketable yield for hand dug transplants were higher than machine dug transplants for 'Camarosa'
and 'Sweet Charlie' during most harvest periods and for the whole season. The exception was for March 2000 when
'Sweet Charlie' machine dug plants had slightly higher yields. 'Camarosa' produced higher yields than 'Sweet Charlie'
over the course of the season. There was a 127% and 30% increase in marketable yield for hand dug 'Sweet Charlie'
and 'Camarosa' respectively in January 2000. During March 2000, yield differences of-2% and 42% occurred
between hand dug and machine dug transplants of'Sweet Charlie' and 'Camarosa', respectively.
Significant treatment differences were found due to digging technique and cultivar during December of the 2000-2001
season Table 1). 'Sweet Charlie' and 'Camarosa' which were hand dug performed 126% and 120% better than
machine dug plants respectively. However, for the rest of the season no differences were detected for digging
technique and no interactions between digging technique and cultivar were detected. The unusually low air
temperatures during January (.ab.e..3) may have been a major contributing factor in the lack of treatment differences.
Above ground development of all plants appeared to be minimal during this period. Cultivar had a significant effect on
marketable yield each month and for the whole season. As typically observed, 'Camarosa' produced less fruit than
'Sweet Charlie' during the month of December but significantly higher amounts every other month.
Total number of marketable fruit harvested were significantly affected by digging technique during 1999-2000, with
hand dug plants producing a greater number of fruit (Table.2). 'Camarosa' produce a greater number of fruit than
'Sweet Charlie' during the 2000-2001 season. More fruit were produced during the 1999-2000 season than the
2000-2001, probably due to the fact that there was unusually cold weather in west central Florida during January
2001 (Table 3). January is a time when flowers are initiated for the main crop harvested in February and March.
Average fruit weight was affected by cultivar both seasons with 'Camarosa' having heavier mean fruit weight (Table 2).
Number of culled fruit was significantly higher for 'Sweet Charlie' than 'Camarosa' for the 1999-2000 season.
Early production of fruit is highly desirable to Florida growers, with fruit produced in December and January
commanding 2-3 times the price of fruit produced later in the season (Florida Agricultural Statistics,
www.nass.usda.gov/fl). Currently, growers in the major production area of Florida are looking at containerized
transplants to increase their early yields. Research to date on containerized transplants has shown an increase in
early marketable yields when compared to typical bare root transplants (Hochmuth et. al, 2000 ). Their higher early
yield may be partially or wholly explained by the lack of mechanical damage containerized transplants receive during
harvesting, packing and shipping operations. Containerized transplants do not undergo mechanical harvesting
operations, which limits the amount of damage prior to planting. These transplants are left in trays and packed 50 to
200 plants to a box, whereas a similar size box can contain up to 600 bare root transplants. These less compacted
conditions may limit damage during shipping. Containerized transplants are roughly double the cost of machine dug
bare-root plants, however the increased production of high value early fruit may offset this cost.
It is likely that the mechanical damage a green-top bare rooted transplant receives during digging, packing and
transport from the nursery to the fruiting field seriously affects its performance in Florida fruiting fields. A reduction in
performance, especially early in the season, can have a dramatic effect in terms of monetary returns to growers.
Further research examining means to reduce transplant damage during harvest, packing and shipping needs to be
Dufault, R.J. Vegetable Transplant Nutrition. HortTechnology 8:515-523.
Hancock, J.F. 1990. Strawberries. CABI Publishing, New York.
Hochmuth,G., C. Chandler, C. Stanley, D. Legard, J. Duval, E. Waldo, D. Cantliffe, T. Crocker and E. Bish. 2001.
Containerized transplants for establishing strawberry crops in Florida. HortScience 36:443. (Abstr.)
Leskovar, D.I. 1998. Root and shot modification by irrigation. HortTechnology 8:510-514.
Latimer, J.G. 1998. Mechanical conditioning to control height. HortTechnology 8:529-534
Maynard, D.N. and S.M. Olson (eds.). 2001. Vegetable production guide for Florida (SP 170). University of Florida
and Citrus and Vegetable Magazine.
NeSmith, D.S. and J.R. Duval. The Effect of Container Size. HortTechnology 8:495-498
Vavrina, C.S. 1998. Transplant age in vegetable crops. HortTechnology 8:550-555.
Table.1.. Fruit yield data for mechanically dug and hand dug 'Sweet Charlie' and 'Camarosa' strawberry
transplants grown in the annual hill production system at Dover, Fla.
Marketable weight (tons/acre)z
Dec. Jan. Feb. Mar. Total
Hand Dug 1 3.10 5.21 5.40 13.71
Machine Dug 1.89 3.69 4.49 10.07
Sweet Charlie 1- 2.13 3.70 4.34 10.17
Camarosa 1- 2.85 5.20 5.55 13.60
P values (F-Test)
DT 0.0001 0.0018 0.0226 0.0001
C 0.0002 0.0019 0.0046 0.0001
DT XC 0.0050 0.6206 0.0140 0.4717
S0.70 1.98 1 3.23
Machine Dug 0.31 1.76 3.30 2.65 8.03
Sweet Charlie 0.64 1.21 3.15 1.38 6.38
Camarosa 0.37 2.53 3.38 4.30 10.58
P values (F-Test)
DT 0.0007 0.1883 0.7463 0.3393 0.0991
C 0.0089 0.0001 0.2806 0.0001 0.0001
DT X C 0.2320 0.0906 0.8547 0.2788 0.2932
z Numbers represent means of four treatment replications of 16 plants each. Multiply number by 2.24 to
convert to metric tons per hectare.
Table.2. Seasonal data for number of marketable fruit, average fruit weight and total number of cull fruit of
mechanically dug and hand dug 'Sweet Charlie' and 'Camarosa' strawberry transplants grown in the
annual hill production system at Dover, Fla.
Marketable Fruit Average Fruit Total Culls z
(1000's / Acre) Weight (g) (1000's / Acre)
Hand Dug 581 21.7 181
Machine Dug 420 21.7 153
Sweet Charlie 510 18.2 255
Camarosa 491 25.2 79
P values (F-Test)
DT 0.0001 0.9876 0.2303
C 0.4485 0.0001 0.0001
DT XC 0.5809 0.3664 0.5243
Hand Dug 414 19.3 97
Machine Dug 366 19.7 75
Sweet Charlie 327 17.7 90
Camarosa 453 21.3 82
P values (F-Test)
DT 0.0604 0.2864 0.0171
C 0.0001 0.0001 0.3129
DT XC 0.1937 0.2043 0.4700
z Numbers represent means of four treatment replications of 16 plants. Multiply number by 2.47 to
convert to number of berries per hectare.
Table 3. Monthly average high and low temperature(oF) average for Plant City, Fla for the 1999-2000 and
2000-2001 seasons, and the historical average.
Time Period 1999-2000 2000-2001 Historical Average
High Low High Low High Low
November 76.9 56.6 76.0 51.4 79.6 55.7
December 70.9 50.3 71.5 48.7 74.6 50.2
January 71.5 49.2 68.5 42.1 72.7 48.2
February 74.7 48.9 79.6 56.8 74.4 49.7
March 81.3 56.8 77.5 55.7 79.7 54.6
(John R. Duval. Craig K. Chandler, Daniel E. Legard, GCREC-Bradenton; Peter
Hicklenton, Agric. Canada, Kentville, Nova Scotia, Canada Vegetarian 02-01)
.Bi.oQgi.c.a.l.y.-based Disease Management Products in Florida
Methods of biological control of diseases are becoming more widely used in conventional production systems as well
as in organic production systems. Reported advantages of biocontrol methods include increased safety of transport,
handling and application; reduced environmental effects; reduced re-entry and harvest intervals; minimized potential
for development of resistance; and applicability to IPM programs. Biological fungicides may act to suppress the
population of the pathogenic organism through competition with pathogenic organisms, stimulate plant growth which
may allow plants to quickly outgrow any pathogen effects, or damage or destroy the pathogen by means of toxins
A number of soilborne fungi are considered to be limiting to the production of conventionally and organically grown
vegetables for the fresh market. Members of the genera Fusarium, Pythium, Phytophthora, Sclerotium, and
Rhizoctonia are of primary concern. Several biologically-based disease management products have been developed
for use against these fungi. The 8 organisms commercially available in the US as controls for soil-borne diseases in
vegetable crops are listed in Table 1. Several are found in more than one product, generally distinguished by the
formulation. The Organic Materials Review Institute has labeled 8 of these products as allowable for use in certified
A survey by Glades Crop Care of South Florida tomato, potato and pepper growers in 1996-1997 indicated that, while
the majority of growers commonly used IPM techniques of scouting, resistant varieties and cultural controls, the
additionn of) mycorrhizal organisms to transplant or field soil to mitigate soil-borne diseases" was not commonly
used. Frantz and Mellinger (1998) cite the lack of clearly demonstrated efficacy as the primary barrier to the use of
biologically-based disease management products.
A wide variety of disease-suppressing organisms, including most of those listed in Table 1, have been tested in
Florida on different crops and under different conditions. A summary of the results is listed in Table 2. Sources for
the specific tests are listed in the Literature Cited section or were provided by the companies producing the
biocontrol products. As suggested by the Glades Crop Care survey, results varied with crop, variety, cultural
conditions and method of application. However, some studies do show the potential that biofungicides have for
controlling soil-borne diseases. It is important to note that biological control organisms are not meant as stand
alone disease control strategies, in that they suppress but do not control disease. Therefore, these organisms
should be evaluated as components within an integrated system of cultural, chemical and biological controls.
Variations due to site, year, level of disease, cultivar, etc. are the norm and therefore tests must be repeated over
time and location to produce useable results. Information on yield as well as on disease response and the inclusion
of on-farm trials will be more likely to result in adoption of the technology by growers.
Datnoff, L.E. and K.L. Pernezny. 1998. Effect of bacterial and fungal microorganisms to colonize tomato roots,
improve transplant growth and control Fusarium crown and root rot. 1998 Florida Tomato Institute Proceedings PRO
Datnoff, L.E., S. Nemec, and K. Pernezny. 1995. Biological control of Fusarium crown and root rot of tomato in
Florida using Trichoderma harzianum and Glomus intraradices. Biological Control 5:427-431.
Frantz, G. and H.C. Mellinger. 1998. Measuring integrated pest management adoption in South Florida vegetable
crops. Proc. Fla. State Hort. Soc. 111:82-87
Martin, F.N. and C.R. Semer. 1991. Biological control of damping-off of tomato transplants using the non-plant
pathogen Pythium oligandrum. Phytopathology 81:1149.
McGovern, R.J., L.E. Datnoff and L. Tripp. 1992. Effect of mixed infection and irrigation method on colonization of
tomato roots by Trichoderma harzianum and Glomus intraradix. Proc. Fla. State Hort. Soc. 105:361-363.
Meneley, J.C. 2000. Challenges to the commercialization of biological control technologies for IPM. p. 289-304. In:
G.C. Kennedy and T.B. Sutton (eds.). Emerging Technologies for Integrated Pest Management: Concepts,
Research and Implementation, APS Press, St. Paul, MN.
Mitchell, D.J., F.N. Martin and R. Charudattan. 1994. Biological control of plant pathogens and weeds in Florida. p.
549-574. In: D. Rosen, F.D. Bennett and J.L. Capinera (eds.) Pest Management in the Subtropics: Biological
Control a Florida Perspective. Intercept Ltd. Andover, Hampshire, UK.
Nemec, S. L.E. Datnoff and J. Strandberg, 1996. Efficacy of biocontrol agents in planting mixes to colonize plant
roots and control root diseases of vegetables and citrus. Crop Protection 15(8): 735-742.
Organic Materials Review Institute. 2001.OMRI Brand Name Products List Crop Production Materials by Generic
Material. Biological Control; Microbial Products; Microbial Products, Allowed.
Table 1. Commercially Available Biologically-based Disease Management Products for Control of Soil-borne
Organisms in Vegetable Crops.
Active ingredient Product Disease Crop Company
cepacia -Stine Microbial
Blue Circlex Damping off diseases vegetables Produ
Denyx Rhizoctonia, vegetables CCT Corp
Bacillus subtilis Epic ia, legumes Gustafson, Inc.
Kodiak i, legumes Gustafson, Inc.
Companionz, Y Phytophthora, horticultural crops Products, Inc
Tri a Fusarium, Pythium, cabbage,
ri PlantShieldx Rhizoctonia, cucumber, BioWorks, Inc.
Sclerotinia tomato, turnip
Fusarium, Pythium, cbbe
Rhizoctonia, r, BioWorks, Inc.
(drench and Sclerotinia tomato,
T-22 Planter Fusarium, Pythium,
BoRhizoctonia, vegetables BioWorks, Inc.
harzianum, Fusari, Phium, greenhouse crops JH Biotech, Inc
Trichoderma viride Promote Plusx
Gliocladium virens oxysporum, ThermoTrilogy
GL-21 SoilGard 12GX Rhizoctonia solani, vegetables Corp
Gliocladium Ag io
catenulatum Primastop Pythium, Rhizoctonia greenhouse crops Development,
verrucaria DiTera V t
nematodes food crops Corp
(dried fermentation WPX
Table 2. Summ.ary.of results on vegetable crops in Florida.
i Product Disease Crop Type of test Results
ce ia Deny capsi Pepper Lower disease incidence
cepacia capsici (transplant
Deny Pythium Greenhouse No reduction in severity
aphanidermatum cucumber (seed of wilt
Deny Nematodes Tomato (transplant Equal control to Vydate
y P. c i P No reduction in disease
Deny P. capsici Pepper
B s Kodiak P Colonized roots
subtilis tomato (transplant
Kodiak P. capsici Pepper Redced ee
No reduction in disease
Kodiak P. capsici Pepper No redu n in
Z may not be available
Y EPA Experimental Use Permit
x Allowed for organic production by the Organic Materials Review Institute
No reduction in severity
Quantum Tomato incidence on average
rot (transplant 30%
No effect on length and
Quantum Pythium and
Quantum rt Celery
Fusarium root rots (transplant Reduced disease
treatment) incidence in combination
with Glomus intraradices
Ta Not listed Tomato Greenhouse
harzianum Increased plant height
F i Greenhouse
Not listed Tomato I Did not control disease
Field Reduced disease
strain Fusarium crown incidence
KRL-AG2 rot (transplant
drench) Did not increase yield
B Field (grower Higher yield than
trial) untreated control
T-22 Tomato, Colonized roots
Field Reduced disease
-2 Fusarium crown o severity and incidence
rot (transplant (not significantly different
treatment) from control)
No reduction in severity
-2 P. No reduction in disease
T-22 P. capsici Pepper i
Good root colonization
treatment) Higher yields in
fumigated soil (not
Gliocladium Control equal to
Gioc m not listed Pythium spp. Tomato Field equal t
Glioguard Tomato, Colonized roots
SoilGard Tomato, Transplant No plant stimulation or
pepper study yield increase
No reduction in severity
SoilGard P.aphanidermatum o io i i
cucumber (seed of wilt
No reduction in disease
SoilGard P. capsici Pepper No reduce in
No reduction in disease
Field incidence or severity. No
Fusarium crown increase in yield on
rot (transplant fumigated soil. Trend for
treatment) increased yield on
(Betsy Lamb, IRREC-Ft. Pierce and Erin Rosskopf, ARS-USDA -Fort Pierce Vegetarian
||I Vegetable Postharvest Information on The Internet |
Rapid access to timely, unbiased information is vital to maintaining competitive produce growing, packing and
shipping operations. Ten years ago, one often needed to travel a considerable distance to the nearest university or
college library to access scientific and extension publications or recommendations. In the past decade, however,
computer technology and on-line resources have become much more extensive, reducing the need to physically
travel to libraries. Even newsletters, with the most up-to-date information, are increasingly being sent out to
subscribers via the Internet and e-mail more rapidly than by regular mail. On the Internet, one can find a wide variety
of information ranging from commodity handling recommendations to market reports, and from procedures for
maintaining food safety to specifications on products and services. Other benefits of the Internet include 24-hour
access to the most current information, searchable databases of information, e-mail links to people with additional
information on a subject, and the potential to form on-line discussion groups to share ideas on a particular topic.
With the growing number of web sites containing valuable, easy-to-access postharvest information, the incentive is
greater than ever for individuals (esp. industry) to utilize these resources.
How and where does one actually find postharvest information on the Internet? One way is by using a web search
engine such as Google (ill p '. '' .k. 'k -.,m/ Alta Vista (www.altavista.com), HotBot (www.hotbot.com), or Yahoo
(www.yahoo.com). Web 'crawlers' such as "Dogpile" (hl ip '. 1 ,. .dogpile.com/) can often find more information by
pooling the resources of several different search engines. One drawback of using search engines, though, is that
they often return sites not particularly related to the topic of interest but simply have the search words) present
somewhere in the page. Once a useful web site has been found, it often includes links to similar web sites so that
further information on that topic can be found by following the links. By saving or "bookmarking" particularly useful
sites with links to other related sites, one can easily return to the source of information.
The University of Florida's main postharvest site is the UF Postharvest Programs and Information website
(http://postharvest.ifas.ufl.edu). At the site, one can search for information using key words or by using the topical
index to browse information organized into the following subject areas:
Pre- Harvest Factors Affecting Quality
Maturity Standards & Quality Attributes
Use of Ethylene
Fresh Cut Produce
Cooling. Humidity Control & Cold Storage
Diseases. Disorders & Decay Control
Sanitation & Food Safety
Quarantine & Pest Control
Marketing. Economics. Trade & Statistical Information
Modified & Controlled Atmospheres
General Postharvest Information
In each of the above sections, information from UF sources is featured, but links to other university/government
organizations and selected commercial sites are also provided. Links to sites other than UF/IFAS sites are provided
as a service and do not imply endorsement of information or products. The general postharvest information section in
particular includes links to other sites containing a broad range of additional postharvest information. The UF
Postharvest Programs and Information web site also includes contact information for UF faculty involved in
postharvest research and/or extension. A section featuring upcoming and previous events is included with materials
(handouts) from different past UF postharvest workshops such as the Postharvest Institute. This site is continuously
updated, so check back often for the latest postharvest information and programs offered by the University of Florida.
(Ritenour, Sargent, and Brecht Vegetarian 02-01)
Extension Vegetable Crops Specialists
Daniel J. Cantliffe
Professor and Chairman, Horticultural Sciences
Timothy E. Crocker
Professor, deciduous fruits and nuts, strawberry
Assistant Professor, strawberry
Assistant Professor, vegetable production
Elizabeth M. Lamb
Assistant Professor, production
Assistant Professor, soils
Donald N. Maynard
Stephen M. Olson Jam
Professor, small farms
University of Florida
Institute of Food and Agricultural Sciences
Horticultural Sciences Department
Florida Cooperative Extension Service
North Florida Research and Education Center Suwannee Valley
Mark A. Ritenour
Assistant Professor, postharvest
Ronald W. Rice
Assistant Professor, nutrition
Steven A. Sargent
Assistant Professor and editor, vegetable nutrition
William M. Stall
Professor, weed control
James M. Stephens (retired)
Professor, vegetable gardening
Charles S. Vavrina
?s M. White (retired)
ciate Professor, organic farming
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