INSTITUTE OF FOOD AND FLORIDA
AGRICULTURAL SCIENCES COOPERATIVE
j IFADlS UNIVERSITY OF FLORIDA EXTENSION SERVICE
A Vegetable Crops Extension Publication
Segetable Crops Department 1255 HSDPP Gaincvillc, FL 32611 Telephone 392-2134
Vegetarian 87-10 October 12, 1987
SI. NOTES OF INTEREST
----- A. Vegetable Crops Calendar.
B. New Publications.
';' II. PESTICIDE UPDATE
) A. Specific Exemptions (Section 18) for Use of
Bolero on Celery and Lettuce.
F- ..B. Weed Identification Set From Southern Weed
.' Science Society.
." C. Section 18 for Sodium Chlorate for Preliarvest
Desiccant on Southern Peas.
SIII. COMMERCIAL VEGETABLES
IT I A. Foliar Nutrient Sprays Help Your Growers
Separate Fact From Fiction.
B. Avoid Herbicide Drift.
C. Direct Marketing to Tourists.
IV. VEGETABLE GARDENING
A. Palm Beach County Gardening Survey, 1987
Note: Anyone is free to use the information in this
i newsletter. Whenever possible, please give credit to the
L The use of trade names in this publication is solely for
h *the purpose of providing information and does not
I 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.
COOPERATIVE EXTENSION WORK IN AGRICULTURE AND HOME ECONOMICS, STATE OF FLORIDA, IFAS, UNIVERSITY OF
FLORIDA, U. S. DEPARTMENT OF AGRICULTURE, AND BOARDS OF COUNTY COMMISSIONERS COOPERATING
I. NOTES OF INTERESTS
A. Vegetable Crops Calendar
November 3-5, 1987. FSHS Convention.
Orlando Hyatt Hotel.
November 6, 1987. ASHS Tours. Or-
lando Hyatt Hotel.
November 8-12, 1987. ASHS Convention.
Orlando Hyatt Hotel.
November 19, 1987. 9:00 am 3:30 pm
Tenth Annual Conference for Vegetable
Technical and Sales Reps. Kendrick
Auditorium, Manatee Co. Ext. Office,
1303 17 Street, Palmetto. (Contact
Phyllis Gilreath (813) 722-4524.)
November 30 December 2, 1987. USDA
Vegetable Collaborators' Conference.
Omni Hotel, Charleston, SC (Contact
December 7-11, 1987. Vegetable Crops
Departmental Review. University of
B. New Publications
Leek Variety Evaluation, Fall-
Winter 1986-1987. GCREC Res. Rept.
BRA 1987-17 by D. N. Maynard.
Annual Rhubarb Production, Fall-
Spring 1986-87. GCREC Res. Rept.
BRA 1987-18 by D. N. Maynard.
Okra Variety Evaluation, Spring-
Summer 1987. GCREC Res. Rept. BRA
Knott's Handbook for Vegetable
Growers, for sale from Florida Sci.
Source, Inc., P.O. Box 927, Lake
Alfred, FL 33850. (Price $26.25,
II. PESTICIDE UPDATE
A. Specific Exemptions (Section
18) for Use of Bolero on Celery and
The Environmental Protection
Agency (EPA) has granted specific
exemptions, pursuant to Section 18 of
the Federal Insecticide, Fungicide
and Rodenticide Act, to the Florida
Department of Agriculture and
Consumer Services for the use of
Bolero (thiobencarb) to control
purslane and barnyardgrass in celery
and lettuce, endive, and escarole
grown on organic soils.
Celery. Bolero is to be applied
at a maximum rate of 8.0 lb a.i. per
acre in a single application at the
time of transplanting, prior to weed
emergence. A 70-day preharvest
interval will be observed. A maximum
of 9,100 acres of celery grown on
soils with greater than 20% organic
matter may be treated by ground
equipment using a minimum of 20 gal-
lons of water per acre.
Lettuce, Endive, Escarole. A
maximum of 14,000 acres of lettuce,
endive, and escarole grown on soils
with greater than 20% organic matter
may be treated. A single ground
application at a rate of 6.0 lbs a.i.
per acre in 60 to 80 gallons of water
per acre at the time of direct seed-
ing or transplanting and prior to
weed emergence is authorized. A
45-day p.h.i. will be observed.
Both specific exemptions expire
on August 31, 1988.
(Stall: Vegetarian, 85-10)
B. Weed Identification Set From
Southern Weed Science Society.
The Southern Weed Science
Society has published two new weed
identification guides. These are in
looseleaf form with colored pictures
of the different growth stages of
each weed. On the reverse side of
each sheet is information on biology,
ecology and geographic distributions
of the species. Two sets of 50
sheets each are presently available.
The sets are designed for use in the
southern states. A copy of the order
blank for the sets is below.
(Stall: Vegetarian, 87-10)
C. Section 18 for Sodium Chlo-
rate for Preharvest Desiccant on
A section 18 specific exemption
has been granted for the use of Defol
6 sodium chlorate on southern peas as
a preharvest desiccant. A single
aerial or ground application may be
made on 800 acres at a maximum rate
of 6 Ibs a.i. per acre.
A preharvest interval of seven
days must be observed and no foliage
or fodder from the treated fields can
be used as livestock feed as hay or
graze. The specific exemption
expires December 31, 1987. A supple-
mental label must be in the posses-
sion of the applicator before
application is made.
(Stall: Vegetarian, 87-10)
ORDER FORM SWSS Weed Identification Guide
TO: Southern Weed Science Society, 309 West Clark Street, Champaign, IL
Please forward the following (orders of 100 copies or more will receive a 20%
Sets of SWSS Weed ID Guide I @ $15.00 per set
Sets of SWSS Weed ID Guide II @ $15.00 per set
SWSS Weed ID Binders @ $7.00 each
Advance payment required. Remittance of US $
III. COMMERCIAL VEGETABLES
A. Foliar Nutrient Sprays-Help
Your Growers Separate Fact From
Recently, we have been receiving
increasing amounts of questions con-
cerning foliar fertilization. Most
questions revolve around selecting
the best foliar fertilizer material
and does not address the REAL QUES-
TION of whether or not the sprays are
needed. As extension personnel, we
must help the grower determine the
applicability of foliar nutrition and
help him separate fact from fiction.
Vegetable plant leaves, in the
first place, are not well adapted for
absorbing nutrients because of the
presence of the waxy cuticle. In
fact, it is almost impossible to find
reports in the literature that con-
clusively showed that the plants
benefitted from the sprays rather
than from the nutrients washed from
the leaves onto the ground with
subsequent root uptake.
The application of macronutri-
ents such as nitrogen, phosphorus,
and potassium to plant leaves is
extremely questionable. A glance
through the literature and even
previous Vegetarian articles dating
back through the years should help
put this idea as a general fertilizer
practice to rest. Plants cannot
absorb enough N, P, or K solely
through the leaves to supply the crop
need even under a deficiency.
Especially in Florida, the prac-
tice of N, P, and K foliar fertiliza-
tion should be questioned. Our
vegetable soils are, for the most
part, loaded with phosphorus, and the
large amounts of fertilizer added to
the soil makes one wonder how the
tiny bit of N, P, or K coming from a
foliar fertilizer can significantly
add to that which comes from the
soil-applied fertilizer. A quick
calculation will show that the amount
of foliar-derived macronutrients is
negligible compared to soil derived
fertility. So, why spray these
expensive sources of N, P, or K on
The bottom line is whether or
not foliar N, P, or K actually
increases yields. Some foliar
fertilizer is sold on the premise
that "it supplements a sound soil-
applied fertilizer program." If the
soil directed program is sound, then
it needs no "supplementing."
Foliar nutrients are seen by
some to be a miracle cure for many
plant problems, even those unrelated
to nutrition. They are promoted to
reduce blossom loss, help tuber set
on potatoes, reduce drought stress,
help frost damaged plants, increase
plant resistance to insects and
diseases, etc., etc., etc. The first
thing some desire to do after a frost
or hail is to spray foliar nutrients
on the plant. This supposedly gives
the plant a quick "pick-me-up" snack.
Like many well-fed people, these
plants don't need more fertilizer but
rather warmer temperatures. The
likelihood of getting enough benefi-
cial nutrition on plants that have
lost most of their foliage to hail or
frost is miniscule.
Micronutrient foliar fertiliza-
tion to correct a diagnosed defi-
ciency makes more sense than foliar
application of N, P, or K. However,
the problem is that most commercial
foliar sprays contain several micro-
nutrients, if not all of them.
Therefore, it is impossible to
determine to which one to ascribe the
positive response, if in fact there
was one. The tendency is to blast
away with everything.
In the area of micronutrients,
we must deal with a lot of misconcep-
tions. As with macronutrients, we
must determine that there is a REAL
NEED for micronutrients, and then we
must determine if foliar application
is the best way to apply them. In
situations of high soil pH where soil
micronutrients might be made unavail-
able, a benefit might result from
foliar-applied micronutrients. An
example is the alkaline rockland of
Dade county where micronutrients can
be tied up in the soil.
With micronutrients, such small
amounts are needed that they might be
effectively applied foliarly; IF THEY
ARE NEEDED. The problem in Florida
is that much of our vegetable land is
loaded with micronutrients from
"shot-gun" micronutrient packages
added with the dry fertilizer and
from the copper, manganese, and
zinc-containing fungicides and bac-
teriacides used for disease control.
In fact, tens of pounds of some ele-
mental micronutrients are added
annually to an acre through the
Therefore, if a pest control
program includes these micronutrient-
containing materials, and the soil is
loaded up, why spray on more to
provide a snack? In all likelihood we
are leading ourselves down a danger-
ous path of micronutrient buildup in
the soil and resulting plant toxicity
and reduced yields. If a micronutri-
ent problem has been diagnosed, treat
it with only that nutrient and not a
material with all nutrients in a
shot-gun approach. It will be
cheaper in the short-run and lead to
fewer problems in the long-run.
When applying foliar micronutri-
ents, remember that, in general, they
do not translocate easily from older
leaves to newer leaves. Therefore,
one spray will probably not do the
job. This means that multiple
sprays, directed at the young leaves
will be needed (no airplanes). Rates
in each spray must be according to
labeled recommendations for the
Because of this technical diffi-
culty in achieving good coverage, it
might be beneficial to search for
alternatives to foliar application
such as banding micronutrients in the
soil. Remember that it is very easy
to cause a micronutrient toxicity
with foliar sprays in the hopes of
clearing up a deficiency.
In summary, foliar application
of nutrients is not warranted as a
general, shot-gun approach to ferti-
lization. Many years of research and
demonstration show that it is more
effective and more economical to
follow a sound soil-applied program
based on soil testing principles. In
those few cases where micronutrient
application to foliage is warranted
to correct a diagnosed deficiency, be
1. Identify a REAL need i.e. DEFI-
2. Make sure a yield response
(increase) will result. Don't
spray to make plants greener.
This is the real "acid test" for
foliar nutrition and the one
which most programs fail to pass.
3. Use only the nutrient that is in
deficient supply. Most liquid
fertilizer formulators have these
individual ingredients. Don't
4. Apply at recommended rates and
times to get the maximum re-
5. Search for a program that deals
with the basic problem e.g. soil
pH, cold soils. Don't keep
treating the symptoms with sprays
when you can find a more practi-
cal solution to the problem.
6. Base all decisions on fact and
don't let fiction get in the way.
(Hochmuth: Vegetarian, 87-10)
B. Avoid Herbicide Drift
Reducing pesticide drift, speci-
fically herbicide drift, is a persis-
tant problem confronting applicators.
The problem is not a simple one, but
there are measures that can be used
to reduce drift. The big 3 factors
that affect drift are: wind veloci-
ty, spray droplet size and nozzle
Wind velocity: To best confine
the materials to the target area, the
wind velocity should be zero. Obvi-
ously, in most cases in Florida, this
is impossible. There have been docu-
mented cases where herbicides have
drifted more than 22 miles when
applied under high wind conditions.
The hazards associated with this kind
of drift is sobering when viewed in
the liability standpoint.
Droplet or particle droplets
averaging 400 microns (2/100 inch)
would drift off target about 8 feet
when sprayed from 10 ft in heighth as
from an aircraft. Fine droplets of
100 microns would drift 48 feet under
the same conditions. Very find drop-
lets (10-20 microns) can remain
Controlling the atomization
(fine particle size) offers the best
potential for reducing airborne
drift. Increasing the droplet size
results in sprays that readily fall
and allow application in non-ideal
weather conditions. Unfortunately,
coarse sprays may not give the best
coverage, especially in postemergent
applications. To increase coverage
with coarser sprays, an increase in
gallonage must insue. This may be
accomplished by increasing nozzle
size and/or increasing pressure. For
herbicide applications, use either
flat fan or flood-jet nozzles. Hol-
low cone-type nozzles produce fine
The pressure must be adjusted to
the nozzle size. The higher the
pressure, the greater potential for
atomization. This would result in
more drift. Conversly, if the
pressure is less than that specified
for the nozzles, uneven distribution
of the spray may result.
An obvious method for reducing
drift is by shielding the application
areas. This is done routinely in
directed applications between mulched
beds. Even with shielded applica-
tions, however, if the nozzle and
pressures are not matched, atomiza-
tion of some of the spray occurs and
damage has been done to crop plants
from the short drift of the fine
particle size or atomized spray.
Height of Nozzles: Another
important consideration in reducing
drift is the height of the nozzles.
Nozzles positioned too high will
disperse the spray over a wider area
and increase the potential for drift.
Lowering the nozzles will reduce the
width each nozzle covers. By reduc-
ing the width of coverage for each
nozzle, an increase in gallonage will
be gained by keeping the nozzle and
pressure constant. For broadcast
applications, more nozzles must be
used to obtain proper coverage. The
applicator must decide on a desired
swath width by striking a balance
between pressure, nozzle size and
Physical, chemical, and formula-
tions of herbicides should not be
ignored in drift reduction. The
obvious example here are forms of
phenoxy herbicides. The ester forms
are more prone to evaporate from the
droplets in the air or on plants and
move than the amino-salt formula-
tions. Other herbicides with low
vapor pressure potentials may have to
be specially handled or not applied
at all under certain conditions.
When labeled, the granular formula-
tions of certain herbicides may be
the choice over EC formulations to
reduce drift of spray particles.
In most cases, with planning and
calibration, drift can be avoided.
Measures to avoid this problem should
always be first in the applicators
(Stall: Vegetarian, 87-10)
C. Direct Marketing to Tourists
Tourism and agriculture are
Florida's two largest industries.
Direct marketing of farm products
directly link these two major forces
in the state's economy.
Direct marketing includes road-
side or on-farm markets, U-pick oper-
ations, and farmer's markets. There
are opportunities to increase direct
marketing in Florida. A good assort-
ment of high quality, fairly priced
vegetables is essential to the
success of any direct-marketing
A survey conducted in Michigan
indicated that there are a number of
other factors that tourists consider
to be desirable in direct-marketing
It probably is not possible for a
single operation to have all of these
attributes, but they should be
considered for planning purposes.
Vegetables, in order of impor-
tance, that were effective in drawing
Michigan tourists to direct-marketing
facilities were sweet corn, straw-
berry, lettuce, muskmelon, tomato,
potato, carrot, cucumber, broccoli,
and cauliflower. Some of these
vegetables would be important to
Florida too; others that could be
added here are watermelon, okra,
southern pea, pepper, greens, and
squash. In Manatee County, rhubarb
attracts northern visitors to some
Farm products, other than
vegetables, were also important in
attracting tourists to direct-market-
ing operations. Some that could fit
into Florida operations are eggs,
milk, jams, jellies, preserves, fruit
juice, honey, smoked fish, blueber-
ries, and peaches. Citrus would be
an obvious addition to the list for
Another important part of the
Michigan survey was to determine how
customers learned of the availability
of farm products. This is how they
Informal/word-of-mouth .. .51%
Roadside sign . . .21%
Newspaper . . .10%
Travel Information Center . 3%
Radio, Magazine, TV. .each 1%
Chamber of Commerce less than 1%
Even though word of mouth was a very
important means of communication in
this study, advertising to make
customers aware of produce availabi-
lity should not be overlooked.
For more information on roadside
marketing, see VC-33.
1. Propst, D.B., P.S. Newmyer, and
T.E. Combrink. 1986. Direct
marketing of agricultural pro-
ducts to tourists. Mich. Coop.
Ext. Bul. E-1960.
2. Sherman, M. 1985. Produce
handling for roadside markets.
Fla. Coop. Ext. Veg. Crops Fact
(Maynard, Vegetarian, 87-10)
IV. VEGETABLE GARDENING
A. Palm Beach County Survey,
Gene Joyner, Extension Horticul-
turist in Palm Beach County has
surveyed gardeners attending his veg-
etable classes in the Fall of 1987,
with some interesting results. Since
Gene doesn't mind, I'm going to
condense his survey reports and share
some of the highlights with our
There were 60 responses out of
200 attending classes.
1. Where living?
Urban 40; Rural 19
My comments: Shows that term
"Urban Horticulture" is often
too exclusive and leaves out the
rural areas of our counties.
2. First time garden?
Yes 8; No 45
My comments: This is usually
the case, but experience may
have been in another state.
3. Average size of garden:
360 sq. ft.
My comments: Right at the aver-
age size as found by Gallup
4. Pre-plant nematode control
Yes 32; No 16
My comments: Shows importance
of this pest; many plan, but
5. Favorite vegetable grown:
tomato, beans, radish, broccoli,
peppers, squash, cauliflower,
herbs, eggplant, cucumbers,
peas, sweet corn, lettuce, on-
ion, parsley, cabbage, and
collards (not quite in that
My comments: Again, the Gallup
Poll would concur.
6. Irrigation used?
Sprinkler 29; Hand 28.
My comments: The easy way is to
use the lawn sprinkler.
7. Do you use Extension's gardening
Yes 44; No 3.
My comments: Keep in mind this
meeting was one in a series.
8. How are vegetables used?
Fresh 42; Other 10
My comments: Need some work on
9. Money spent on gardening:
Lawn $245; Fruits $39; Shrubs
$93; Flowers $42; Vegetables $48
My comments: These figures for
vegetables very close to Gallup
10. What prompted you to participate
in Extension's home horticulture
a. Mass media announcements 47
b. Recommendations by friends 14
c. Garden club or other
organization announcements 5
d. Referral by garden stores,
nurserymen, etc. 6
My comments: As expected, the
newspaper, radio, and TV are
best ways to round up a crowd.
(Stephens: Vegetarian, 87-10)
Prepared by Extension Vegetable Crops
Dr. D.J. Cantliffe Dr. D.D. Gull
Chairman Assoc. Professor
Dr. G.J. Hochmuth
Dr. W.M. Stall
Dr. D.N. Maynard
Mr. J.M. Stephens