COOPERATIVE EXTENSION WORK IN
AGRICULTURE AND HOME ECONOMICS
(Acts of May 8 and June 30, 1914)
Agricultural Extension Service, University of Florida
Florida State University and
United States Department of Agriculture, Cooperating
H. G. Clayton, Director
SWEET POTATO PRODUCTION
(Prepared in cooperation with workers of the
Florida Agricultural Experiment Stations)
AGRICULTURAL EXTENSION SERVICE
UNIVERSITY OF FLORIDA
Producion practices are subject to rapid change
by new problems and the application of research
results to meet these needs. No attempt is made
here to foresee all the complications possible, but
instead to present the current pertinent facts on
sweet potato production. Experienced growers
may have several modifications of these practices
for their specific conditions.
For further details on local application of these
facts, contact your County Agricultural Agent.
FLORIDA AND LEADING COUNTIES'
HARVESTED ACREAGE, PRELIMINARY
REPORT 1950 CENSUS:
Alachua 490 Okaloosa 197
Calhoun 221 Pasco 169
Columbia 250 Santa Rosa 188
Escambia 246 Sumter 206
Gadsden 514 Suwannee 159
Holmes 284 Walton 178
Jackson 656 Washington 178
Jefferson 814 48 + Others 1,716
Madison 163 Total 7,131
FOUR SEASONS' YIELDS, COSTS AND
RETURNS PER ACRE, LA CROSSE AREA
(Based on Representative Growers' Records and Estimates)
to t- 00 Q)%0
Bushels per acre 75 84 63 51 68
Production cost $171 $150 $126 $140 $147
Harvesting cost 72 70 34 48 56
Sales 181 335 227 144 222
Net return -62 +113 +67 -44 +19
Set Draws or
Bed Seed Vine Cuttings
North Florida Feb. 15 to Apr. 15 April 1 to June 1
Central Florida Jan. 15 to Apr. 15 March 1 to June 1
South Florida Oct. 1 to Apr. 1 Nov. 15 to May 15
40 to 45 days,
soil at 80 F.
120 to 140 days
150 days or more
Aug. 1 to Nov. 1
July 1 to Nov. 1
June 15 to Dec. 1
UNIT NO. 1 OR COPPER-SKINNED PORTO
RICO.-Standard vining type.
CLIETT'S BUNCH.-Bush type, recommended
on a trial basis only. Acceptable yields and qual-
ity, but reported difficult to secure sufficient pro-
duction of plants. Several similar selections avail-
(Electric, manure or flue-heated with soil tem-
perature at 80-850 F.)
Seed Size.-11/" or larger in diameter, No. 1
and Jumbo size from vine cuttings or cut sprouts.
Spacing, Covering.-Allow 12 square feet per
bushel. Place seed adjacent but not touching.
Seed Required.-6 to 7 bushels furnish plants
for 1 acre in 3 pulling.
SEED FIELD-BEDDED IN ROWS
3%' to 4'
Between roots: 6"
Row space per
bushel: 35 yds.
One acre produces
vine cuttings for
Plants for 1 Acre:
8 to 10 bushels in
While thus far no authentic case of boron de-
ficiency in sweet potatoes has been reported in
Florida, other states have reported response to
applications of around 5 pounds borax per acre.
With this element the margin between deficiency
and toxicity is narrow.
DISEASES AND CONTROLS
Seed Selection.-Many diseases may be reduced
by growing enough seed from vine cuttings to
produce next year's seed supply. Select hills at
digging time which are free of disease, have de-
sirable varietal characteristics and have at least
four or five No. 1 potatoes per hill. Seed stock
should be free of internal cork, a disease for which
there is no other known control. Seed stock should
be free from injury. Take special care in digging
and maintaining the seed supply, handling the
product a minimum number of times.
Plant Bed Site.-Locate the bed where sweet
potatoes and tobacco have never been grown or
have not been grown within three years. If per-
manent beds are to be used, remove soil to a depth
of 12 inches, drench the bed and frame with a
solution of 1 pint of formaldehyde per 15 gallons
of water, then refill with new soil.
Semesan Bel. 1 pound to 7/2 to 8 gallons
water for 1 minute; bed, or dry in shade.
Mercuric Chloride.-Dissolve 4 ounces in 1 gal-
lon hot water and add to 31 gallons of cold
water in a clean wooden container; dip for
8 to 10 minutes and bed. After treating
10 bushels add 1 quart of stock solution (1/2
ounce mercuric chloride per quart water)
and add water to 32-gallon mark on container.
Repeat for every additional 10 bushels and
discard for fresh solution after 50 bushels.
Spergon.-1 pound wettable in 5 gallons water;
dip (in and right out), drain and bed.
In General.-Dip to soil line (do not wet leaves)
in Semesan Bel, 1 pound per 10 gallons water.
Stem Rot or Wilt.-Dip base of stem and plant
roots or lower end of vine cutting in wettable
Spergon solution, 1 pound to 8 gallons water.
Scurf.-Dip base of stem and plant roots in fer-
bam solution, 1 pound to 5 gallons water.
INSECTS AND CONTROLS
Gold Bugs-5% DDT.
Grasshoppers-5% chlordane; 10% toxaphene.
Leaf-eating Caterpillars--5% DDT; 5% chlor-
dane; 10% toxaphene.
Sweet Potato Weevil-Sanitation; certified o:
White-fringed Beetle Adherence to quaran-
tine. It has been reported that 5 pounds technical
DDT per acre, mixed into the soil, prevents breed-
ing of this insect for 5 years.
CURING AND STORAGE
Tightly built barns can be used: A 16' x 16'
barn of average height stores 1,000 bushels. Al-
low 21/2 cubic feet per bushel basket.
Do not wash sweet potatoes before curing and
Clean and fumigate storage house and any used
containers. Rat-proofing measures are in order.
Curing takes place best at 850 F. and high hu-
midity (85%). Controlled ventilation is necessary.
Begin timing the period after the recommended
temperature and humidity has been reached with
the potatoes in place in the curing room. A curing
period of 8 to 12 days is usually sufficient. Every
effort should be made to adjust to storage condi-
tions quickly, but without causing "sweating" of
Storage temperatures should be maintained at
550 F. and never allowed below 500 F. If soft rol
becomes excessive during storage the temperature
should be maintained at 750 F. until the potatoes
are dried out.