INSTITUTE OF FOOD AND
UNIVERSITY OF FLORIDA
A Vegetable Crops Extension Publication
Vegetable Crops Department 1255 HSPP D aiine1wilc, FL 32611 Tlcphlone 392-2134
September 14, 1990
I. NOTES OF INTEREST
B. Southwest Florida REC Vegetable Field Day
and Trade Show.
II. COMMERCIAL VEGETABLES
A Vegetable Variety Demonstrations.
B. Postharvest Short course- March 11-15, 1991.
/I C. Pesticide-Based Copper Toxicity in Tomato.
SIll. A. Enquik Label in Strawberries.
IV. VEGETABLE GARDENING
A. Educational Organic Gardens Progress Report.
Note: Anyone is free to use the information in this newsletter.
.': ,;, Whenever possible, please give credit to the authors. The purpose of
.i r trade names in this publication is solely for the purpose of providing
information and does not necessarily constitute a recommendation of
., the product.
The Institute of Food and Agricultural Sciences is an Equal Employment Opportunity Affirmative Action Employer authorized to provide research,
educational information and other services only to individuals and institutions that function without regard to race, color, sex, or national origin.
rnnPFRATIVF FXTFNSION WORK IN Ar.RirIII TIIRF ANn i4-rMF FrnNnMICr STATE OF FLORIDA IFAS UNIVERSITY OF
I. NOTES OF INTEREST
October 1, 1990. Vegetable
Packinghouse Operators and Managers
Seminar. Will meet at Tomatoes of
Ruskin packinghouse in Ruskin from 2:00
PM to 5:30 PM. Contact: Karl Butts
(813-621-5605) or Phyllis Gilreath (813-
722-4524) or Steve Sargent (904-392-7911)
for more information.
October 10, 1990. Florida Pepper
Institute. Palm Beach Extension Office,
North Military Trail.
October 26-28, 1990. National
Junior Horticultural Association
Convention. Green Bay, Wisconsin.
November 13, 1990. Southwest
Florida Research & Education Center's
Vegetable Field Day and Trade Show.
(Contact Charlie Vavrina).
March 11-15, 1991. Commercial
Harvest and Postharvest Handling of
Horticultural Crops. For Extension
faculty, packinghouse managers, graduate
students. Will consist of one day of
seminars and four days of tours.
October, 1991. National Junior
Horticultural Association Convention.
Orlando. (Contact Dick Wooton).
B. Southwest Florida Research
& Education Center's Vegetable Field Day
and Trade Show.
Please mark your calendar for
November 13, 1990 for the Southwest
Florida R.E.C. Vegetable Field Day and
Trade Show. At 9:00 am there will be a
morning educational program followed by
a sponsored luncheon. Field tour of
research plots from 2pm 4pm. The
Trade Show will be ongoing throughout
the day. Proceedings will be published
and distributed at the Field Day. Please
call Southwest Florida REC (813) 657-
5221 to preregister.
(Vavrina, Vegetarian, 90-09)
Allred, A. J. and G. Lucier. 1990.
The U.S. Watermelon Industry. USDA,
ERS Staff Report AGES 9015. Available
from ERS-NASS, P.O. Box 1608, Rockville,
MD 20849-1608. $11.00
E. E. Albregts, C. M. Howard, and
C. K. Chandler. January, 1990. 1990
Climatological Report and Historical
Information from 1929-1990. Dover AREC
Research Report DOV-1990-1.
E. E. Albregts, C. K Chandler, and
C. M. Howard. June, 1990. Strawberry
Variety Trials 1989-90. Dover AREC
Research Report DOV-1990-2.
Arthur W. Engelhard. May 1990.
Using IPM for Disease Control.
Bradenton GCREC Research Report
Will E. Waters and J. P. Jones.
1989. Highlights of Significant Research
and Development. Ornamental,
Strawberry, and Vegetable Crops. GCREC
Bradenton Research Report BRA 1990-12.
II. COMMERCIAL VEGETABLES
As a new vegetable production
season is beginning, agents may want to
consider including vegetable variety
demonstrations in their educational
programs. Over the years, extension
demonstrations have been proven to be
one of the most effective means of
communicating new ideas and
technologies and the use of improved
methods and varieties. Successful
demonstrations require careful planning
and a committed cooperator. Some of the
factors to be considered when establishing
a vegetable variety demonstration follow.
Variety trial demonstrations should
be conducted 'in season', i.e. planting
should be at the normal time in your area
for the crop being evaluated.
At the time the demonstration
variety trial is actually established in the
field, you have already made an
agreement with the cooperator, selected
the varieties to be included, and obtained
the needed seed or transplants.
There are at least two general
procedures that can be followed in trial
1. Mark out a representative plot of
the required size which the
cooperator will leave for you to
seed or transplant by hand or with
small equipment. It usually works
best for the cooperator to plant the
field, except for the plot area, and
then for the demonstration area to
be planted immediately thereafter.
2. Where seed supplies are plentiful,
the crop is mechanically
established, and the varieties to be
evaluated are acceptable on the
market, the plots can be seeded in
rows with the cooperator's
equipment. When the plants
emerge, uniform areas in the field
can be selected for observation,
yield and other appropriate
Whichever method of establish-
ment is used, mark the plot clearly with
field stakes and flags and make a field
map showing all the plots and
surrounding area. Photocopy the map
and make sure the cooperator gets a copy.
Randomized complete block or
completely randomized designs are most
frequently used for variety trials. Plot
size and number of replications are
determined by the variability of the site
and the plant material being evaluated.
Commercially available seed is ordinarily
quite uniform, so that is not usually a
source of variability. Four replicates are
generally satisfactory and acceptable. Plot
size or the number of plants per plot is
less definite and harder to establish with
certainty. For tomatoes and peppers, 8 to
12 plants might be satisfactory, whereas
60 to 100 plants might constitute a
minimum size bean plot. In any event,
guard rows and plants will help reduce
variability and thereby increase precision.
It may be useful to allot space at the
beginning of the trial plot to plant short
rows of all of the varieties included in the
trial. These rows can be left unharvested
to show to field day participants.
Observation rows are especially useful for
leaf and root crops that are destructively
Sometimes it may be unrealistic to
plan a replicated trial for certain
vegetables that require frequent and
multiple harvests like summer squash,
okra, or strawberry. In these cases, single
plots of each variety, two or three times
larger than that suggested in the
individual crop section may be used.
Every extension vegetable agent
should have a copy of Circ. 762, Vegetable
Variety Evaluation Demonstrations: A
Manual for County Extension Faculty
which provides detailed information on
the topic. If yours is missing, or you
need another copy, please let me know.
(Maynard, Vegetarian 90-09)
B. Postharvest Short course -
March 11-15, 1991.
The course Commercial Harvesting
and Postharvest Handling of Horticultural
Crops will be offered during the week of
spring break. For the first time the
course will be open to extension faculty
for graduate credit and industry personnel
for Continuing Education Units. The
course will also be expanded to include a
one-day short course on campus at
Gainesville, followed by a four-day tour of
Florida horticultural industries.
The short course will include the
latest practical information for postharvest
handling of vegetable, fruit (tropical and
subtropical) and ornamental crops, and
will present the concept of systems
analysis as a tool for evaluating and
optimizing postharvest operations. Topics
to be presented will include:
*packing line performance
*modified and controlled
The tour will consist of visits to a
wide variety of harvest, packing and
shipping operations throughout the state,
as well as stops at a port facility and a
warehouse operation. The tour will leave
Gainesville on March 12 and return to
Gainesville on March 15. Contact Steve
Sargent for further details (904-392-7911).
(Sargent, Vegetarian 90-09)
C. Pesticide-Based Copper
Toxicity in Tomato.
Many growers have questioned the
long-term effects of the copper-based
bactericides used in tomato production.
Copper in excess amounts, can cause
toxicity to plants and it accumulates in
the soil. In a typical growing season,as
much as 25 to 30 pounds of copper are
applied per acre to control bacteria
diseases such as bacterial spot on
tomatoes or pepper. Copper in addition
to this amount might be added at the
rate of 1 to 4 pounds per acre from the
fertilizer. Copper concentration builds to
high levels in soil used continuously for
vegetable production, especially in tomato
and pepper fields.
Research at the North Florida
AREC in Quincy by Drs. Fred Rhoads and
Steve Olson showed that tomatoes can be
negatively affected by high copper
concentrations in the soil. In soils with
pH 5.5 or less, there was a linear decrease
in plant growth as copper rate was
increased from zero to 1400 pounds per
acre. There was an approximate 30%
decrease in growth with the first addition
of 350 lb per acre of copper. This
roughly represents 12 years of copper
additions. Liming the soil to pH 6.5
effectively eliminated copper toxicity
except at very high copper rates. Growth
was still reduced, even at pH 6.5 when
over 700 lb per acre of copper was applied
(more than 20 years of accumulation).
In field situations, the reduction in
growth might not be so dramatic as to be
easily noticeable. However, with time
yield reductions could occur.
Tissue copper concentrations of 30
ppm and above seemed to be associated
with copper toxicity (reduced growth).
However, growth was not reduced in all
cases of tissue with 30 ppm or above
copper. This means that tissue-copper
concentration alone might not be a good
indicator of toxicity.
There are some suggestions to
avoid problems in future years from
copper toxicity. These are:
1. Follow soil-test predicted liming
programs. Lime to pH of 6.5 for
soils with large copper
concentrations (probably those with
Cu above 50 ppm Mehlich-I Cu.
2. Follow soil-test predicted copper
fertilizer programs. Do not add
copper in the fertilizer when it is
3. Where possible, grow disease
resistant or tolerant cultivars.
4. Try to use brands of copper
pesticides that can achieve control
at very low copper rates.
5. Apply copper only when needed
and at recommended rates with a
carefully calibrated sprayer.
6. Rotate when possible to crops that
do not require heavy copper
7. Avoid overhead sprinkler irrigation
which could increase disease
severity, requiring more copper.
8. Deep plow soil to dilute copper
(Hochmuth, Vegetarian 90-09)
I. PESTICIDE UPDATE
A. Enquik Label in Strawberries.
Enquik herbicide has been granted
a 24C Special Local Need registration in
Florida for the control of weeds in row
middles of strawberries. Apply 5 to 10
gallons ENQUIK as directed, shielded
spray to crop row middles for control of
escaped broadleaf weeds. ENQUIK
herbicide is strictly contact in nature, so
thorough coverage is essential. Flat fan
and hollow cone type nozzles are
recommended. They may be either 80
or 110 with not larger than 04 orifices,
or high pressure hollow cone types.
Flooding-type fans and cone types, which
produce large droplets CANNOT BE
USED. ENQUIK herbicide should be
applied using a high-quality nonionic
surfactant at a rate of 0.25-.50% (2-4 pints
per 100 gallons of total spray volume).
Apply using a minimum boom pressure of
A total spray volume of 20 to 50
gallons per acre with a dilution rate of
water: ENQUIK not to exceed 6:1 is
recommended for best results. ENQUIK
should be applied to small, actively
growing weeds. Where weed populations
are dense, a second application may be
required 3 to 7 days later. Do not apply
to weeds which are wet from rainfall or
dew, or to weeds under drought stress, as
reduced weed control may result. Avoid
spray contact with desirable foliage as
injury may result. A preharvest interval
in not restricted.
(Stall, Vegetarian 90-09)
IV. VEGETABLE GARDENING
A. Educational Organic Gardens -
Back in February the Vegetable
Crops Department kicked off the educa-
tional organic gardening project located
across Hull Road from Fifield Hall on the
University of Florida campus.
As has been stated, the purpose of
the 4-acre project is to learn and teach as
much as we can about growing vegetables
the organic way. The various activities
may be classified as teaching, research,
and/or extension. The bottom line is that
they are educational, so we are calling
Although the initial phase of the
project has involved such start-up proce-
dures as personnel hiring, plot design and
layout, irrigation installation, fence
building, and materials procurement, we
still have managed to grow a lot of
vegetables with a variety of treatments.
The following are some of the more
significant observations recorded during
this first season.
Organic "Model" garden
In this 2,500 square feet garden
we successfully grew a wide assortment
of vegetables commonly grown in Florida
home gardens. These included legumes,
cucurbits, crucifers, solanaceous crops,
salad crops, sweet corn, and okra. In each
and every case we obtained normal,
satisfactory growth and yields of good
We used trickle irrigation for water
conservation, but realized an extra bonus
when we were able to use it during
periods of water restrictions.
On one half the garden we incor-
porated a 1h inch-thick layer of aged
chicken litter. The other half received a
3-inch layer of aged sheep manure. Both
were supplemented with gypsum. No
other fertilizer was used on the plots
(which had not been fertilized in the
previous two years).
For insect control we sprayed
weekly with insecticidal soap and Bt.
Still, we had a problem with ants and
aphids. The ants actually fed on the ter-
minal portions of eggplants, and the pods
of okra, as well as crawling all over our
hands as we picked peas and okra.
Weeds were effectively suppressed
with yard waste and oakleaf mulch.
Several soil treatments of organic
fertilizer and/or soil amendments pro-
duced some interesting observations in
these 50 square feet boxes.
Fresh chicken manure only a few
days out of the cages was applied to one
gro-box at the rate of 20 T/a, which is
roughly 1 pound per square foot. We
arrived at this rate based in part on the
success we had last year with equivalent
amounts of mushroom compost in North
Florida gardens, as well as equivocal rates
Tomatoes and summer squash,
both fruiting type vegetables, grew and
produced very satisfactorily without
supplemental fertilizer and with no
readily observed effects of the fresh
nature of the manure.
Again we had difficulties with ants
feeding on the stems and terminal
portions of eggplants, finally destroying
the plants. Grits applied to the base of
the infested plants did not help.
Agraferm (composted dairy manure)
This composted material was
obtained from a northern state as a by-
product of their dairy industry. We
applied it at the rate of 20 T/a and 40
T/a (non-replicated), or roughly 1 and 2
lbs/sq. ft. Plant response was poor at
both rates, indicating an inadequate
fertility level for tomatoes and squash.
This soil amendment, composted
Appalachicola crab waste, was applied also
at 1 and 2 lbs/sq ft (20 and 40 T/a).
Late seeded black-eye peas grew very well
on both rates, but yielded better at the
higher rate. The okra grew poorly at
either rate, indicating inadequate fertility
level of this particular compost.
Obviously, the peas' ability to fix nitrogen
was a factor in their successful growth.
All okra roots were greatly swollen
by root-knot nematodes, providing some
indication that the crabwaste used did not
live up to its reputation as a nematode
We received yardwaste composted
at Tampa, and applied it to one gro-box
at the similar rate of 1 and 2 lbs/sq ft.
Southern pea growth and yields were
about the same at either rate as in the
crabwaste box. However, again the okra
grew slowly with no yields. Root-knot
nematodes were prevalent in all okra
Yard-waste compost plus Fertrell
Anticipating a fertility deficiency
in the compost, we supplemented this box
with Fertrell (3-2-3), an organic fertilizer
made from seaweed and sea products and
routinely marketed in Florida. We
banded the dry-mix fertilizer at 16 lb/100
sq ft, equivalent approximately to our
usual recommendation of 4 lbs 10-10-
10/100 sq ft. As expected, the peas were
more prolific and yielded more than those
grown without the supplement.
When used alone with 10 and 20
lbs/100 sq ft broadcast at planting time,
fair results were obtained with tomato.
Ants were fewer and less problem than
on the composts/manures. We probably
needed to sidedress later.
We tried another organic fertilizer
which is accepted by some organic
certifying agencies (if not all). Sustane
(5-2-4) is the tradename for a composted
turkey litter which is sold dehydrated and
bagged, ready for use in the garden. We
are seeing good results in its effects on
the progress of a late planting of
sweetpotatoes, when applied at 5 lbs/100
Yard-waste compost-plus poultry litter
This is a replicated trial. Results
have not been analyzed as yet.
Effectiveness of commonly used organic
This is another on-going study (by
the Entomology Department). Results
have not been tabulated.
Our organic gardening area seems
to be generally infested with root-knot
nematodes due to previous cropping prac-
tices. Our cover crop of field peas were
heavily damaged. Our okra on the
poultry manure was heavily root-knotted,
yet produced an abundance of pods. We
noted definite resistance (absence of root-
knot) in the 'Better Boy' tomatoes, while
two Florida derived varieties -
'Floramerica' and 'Homestead' growing in
the same boxes as 'Better Boy' were
heavily infested. 'Better Boy' is widely
grown in Florida gardens.
As has been stated, ants were a
serious problem, particularly to okra and
eggplants; aphids were serious on the
southern peas, and spider mites took out
some of the tomato plants late in the
season. We were unable to control any
of these three with soap plus Bt.
While the organic way involved an
extraordinary amount of labor, we were
able to achieve good to excellent results.
However, I would caution readers to
consider these observations as "leads" to a
better understanding of the treatments
and practices reported, rather than the
final word. We expect to expand on these
observations and continue to explore the
many mysteries of the renascence of the
Touring our plots
Since our ultimate goal is to
impact any knowledge gained to the
organic community, we hope to have
timely field days next spring as our plots
become more presentable. In the
meantime we would welcome visits by
appointment from other educators such
as county agents, Master Gardeners, Vo-
Ag teachers, and 4-H members. We do
not feel we can accommodate the general
public except at specified field days.
Already we have been hosts to such
groups as Master Gardeners from
Hillsborough, Marion, Osceola, Seminole,
Lake, Orange, and Volusia Counties;
Jacksonville Urban Gardeners; several
county agents; television show hosts;
Garden Club Short-Course participants; 4-
H Judging teams; University students;
and University faculty colleagues.
(Stephens, Vegetarian 90-09)
Prepared by Extension Vegetable Crops Specialists
Dr. D. J. Cantliffe
Dr. D. N. Maynard
Dr. W. M. Stall (Editor)
Dr. G. J. Hochmuth
Dr. S. M. Olson
Mr. J. M. Stephens
Dr. J. M. White
Dr. S. A. Sargent
Dr. C. S. Vavrina