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site maintained by the Florida
Cooperative Extension Service.
Copyright 2005, Board of Trustees, University
rowing Sweet Potatoes for Profit
>rs: R. D. William and N. J. Tielkemeier
Cooperative Extension Service/ Institute of Food and Agricultural Sciences/ University of Florida/ John T. Woeste, Dean
PLANNING AND LIMING
Sweet potatoes can be a good cash crop for large
and small farmers in Florida. Small machinery and
only a few supplies are needed to grow quality
sweet potatoes. You can harvest about 200 bushels
an acre if you plant the right way and take good
care of your crop. This guide describes how to
grow sweet potatoes for profit.
You can grow sweet potatoes for about $550 to
$600 an acre in north Florida. At $4 a bushel, you
can make about $800 for 200 bushels of potatoes.
If you subtract all your costs from the amount you
receive for the potatoes, you would make about
$200 to $450 an acre on the crop.
Keep a record of your costs during the season.
After you've sold your potatoes, you can figure
how much money you made or lost.
But before you plant, know who your buyer is
or learn where to sell your potatoes.
PLAN YOUR CALENDAR
Plan your sweet potato production early. Each
step is important and must be done at the right
time. The Sweet Potato Calendar can be used to
help plan each production step you take in grow-
ing your crop.
Check the map in this guide for the correct plant-
ing date for your county. Then decide when to do
each step during the growing season and write the
date on the calendar.
SWEET POTATO CALENDAR
Plan Each Step Carefully
CULTURAL PRACTICE DATE
1. Plan your production calendar.
2. Select the field.
3. Test the soil.
4. Lime the field.
5. Prepare the soil
6. Control nematodes.
7. Fertilize the soil.
8. Select varieties.
9. Buy certified plants.
10. Plant in field.
11. Till the soil and control weeds.
12. Side-dress fertilizer.
13. Use pesticides carefully.
14. Control insects.
15. Prevent diseases.
16. Harvest potatoes.
17. Cure potatoes.
18. Store potatoes.
19. Grade and sort potatoes.
20. Sell potatoes.
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.
Dates for Transplanting Sweet Potatoes
NORTH: March to June
CENTRAL: February to June
SOUTH: December to September
SELECT THE FIELD
Sweet potatoes will grow in most Florida soils.
Select a well drained soil that is fertile. Have water
nearby to irrigate the crop during dry weather if
you can. Try to rotate your crops to have less
trouble with disease, insects and nematodes. Sweet
potatoes grow best after a crop of corn or small
TEST THE SOIL
To grow quality sweet potatoes, you need to
plan ahead. Have your soil tested a few months
before planting. These tests will help you decide
which kind of fertilizer to buy and how much to
use. You can harvest more quality sweet potatoes
if you use the right amount of lime and fertilizer.
To test the soil, take several small samples of
soil from the top 6 inches of the field and place
them in a clean pail. Then mix these samples to-
gether. Fill a clean paper sack or plastic bag with
part of this mixed soil. Write your name clearly
on the sack. Ask your County Agent to send the
sack of soil to the Soil Testing Laboratory. After
several weeks, your County Agent will give you
a report like the one below.
SOIL TEST REPORT
COOPERATIVE EXTENSION SERVICE
Soil pH P20s K20 Ca Mg Other
5.1 320 150 150 30
Apply 25 pounds dolomite lime per 1,000 square feet 2
months before planting. Apply 25 pounds of 4-8-8 fertilizer
per 1,000 square feet at planting and mix into soil.
For more facts on soil testing, ask your County
Agent for a copy of Extension Circular 239.
LIME THE FIELD
Soils can be "sweet" or "sour". Most Florida
soils are "sour" before lime is applied. "Sour"
soils have pH numbers from 4.5 to 6.0. Check
carefully your soil test report. If your soil pH
number is below 6.0, your soil is too "sour" or
Sweet potatoes grow best in "sweet" soils with
pH numbers between 6.0 to 6.5. Lime will raise
your soil pH number and make the soil "sweet."
All crops need calcium (Ca) and magnesium
(Mg) fertilizer to grow. Lime gives both calcium
(Ca) and magnesium (Mg). The best mix is 5 parts
Ca to one part Mg. If your soil has enough magne-
sium, your county agent may recommend a lime
containing only calcium. Follow your agent's
recommendations carefully for highest yields.
When your soil test report shows low amounts
of Ca and Mg, your County Agent will tell you to
add dolomite lime to your soil. This kind of lime
will give you the right amount of Ca and Mg (5 to
1) and will raise the pH level in the soil.
Liming your soil is very important. Lime is one
of the cheapest things your soil and plants need. It
also will help your plants grow next year because
some lime stays in the soil for about 2 years. Be
sure to test your soil every year to know how
much lime must be added to keep the right pH
Lime should be spread or broadcast evenly over
the field at least 2 months before you plant. Mix
LIME T -..
the lime into the soil with a rototiller or tractor
On marl and rockland soils in south Florida,
lime is not needed. But magnesium (Mg) and may-
be iron (Fe) should be used with the basic fertilizer
at planting time.
Read: Florida Extension Circular 440, "Growving
Sweet Potatoes for Profit."
Part II Field Preparation and Planting
Part III Field Production and Pest Management
Part IV- Harvesting and Marketing
Acknowledgements: The authors thank the many
staff and faculty members of the Institute of Food
and Agricultural Sciences (IFAS) including J. M.
Nehiley, L. Carter, P. F. Korsching, W. A. Colette,
G. O. Westberry, J. A. B. Pierce and W. S. Cheshire
for helping develop and evaluate this production
guide. We also acknowledge the support from the
IFAS Center for Rural Development Programs.
The use of trade names in this publication is solely for
the purpose of providing specific information. It is not
a guarantee or warranty of the products named and
does not signify recommendation of the product
to the exclusion of others of suitable composition.
COOPERATIVE EXTENSION WORK IN AGRICULTURE AND HOME ECONOMICS
(Acts of May 8 and June 30, 1914)
Cooperative Extension Service, IFAS, University of Florida
and United States Department of Agriculture, Cooperating
K. R. Tefertiller, Director
This publication was promulgated at a cost of
$ 66.86, or 2.2cents per copy, to provide new
information on growing sweet potatoes to both
large and small producers.
Single copies are free to residents of Florida and may be obtained from the County Extension Office. Bulk rates are available upon
request. Please submit details of the request to C.M. Hinton, Publication Distribution Center, IFAS Building 664, University of Florida,
Gainesville, Florida 32611.