FIELD CORN PRODUCTION
Corn is the most important field crop grown in
Florida. Approximately 500,000 acres are planted
each year. Most of the crop is grown in the area
north and west of Ocala, but some field corn is*
grown in almost every county. About 58 percent
of the crop is harvested for grain and about 40
percent is hogged-off. A small acreage is cut for
Most of the field corn acreage is planted on
mineral soils, but a fairly large acreage is grown
on organic soils, mainly in Marion and Palm Beach
counties. The mineral soils used for production
of corn vary considerably in texture, organic mat-
ter content and drainage and, consequently, in
their abilities to retain and supply soil moisture
to the growing crop. In many cases, low fertility
is a limiting factor in corn production.
Results of research show that corn yields in
Florida can be improved economically by planting
good seed of adapted hybrids, application of ade-
quate quantities of needed plant nutrients, and
spacing plants in accordance with the fertility of
the soil and its ability to supply moisture during
the growing season.
Wider use of improved corn production prac-
tices by Florida farmers during recent years has
resulted in substantial increases in average yield
per acre. For instance, the average yield for the
8-year period 1956-1963 was almost twice that
for the preceding 8-year period 1948-1955, and
the average yield in 1963 was almost 4 times
that for 1948.
Much of the gain resulting from the use of im-
proved production practices is nullified by failure
to control rats and weevils, which every year de-
stroy a high percentage of the grain stored on
Florida farms. Rat-proof storage facilities and
proper use of fumigants for the control of weevils
will protect the money and labor invested in the
crop and permit marketing to better advantage.
LIMING AND SEEDBED PREPARATION
In early fall if a winter cover crop is to be ,.
planted, or during winter if the soil is to be left
bare until corn planting time, have soil tested,
shred crop residues, broadcast the recommended
kind and amount of limestone, and disk land to
incorporate lime and crop residues.
Three to 4 weeks before corn planting time turn
land so that all plant material is covered and
largely will have decomposed before the corn crop
If need for control of white-fringed beetle, wire-
worms or other soil-borne insect pests is indicated,
just before planting time broadcast aldrin or
dieldrin, at appropriate rate, and immediately disk
it into the upper 3 or 4 inches of soil. Recom-
mended rates of application, in pounds of the ac-
tive ingredient per acre on different kinds of soil,
Mineral soils .................. 2 1%
Organic soils .................. 4 3
A. Central, northeastern and northwestern Florida:*
1. Long-season hybrids for cribbing, making silage or
a. Yellow: Coker 67; Coker 71; Dixie 18; Florida
200; Greenwood 471.
b. White: Coker 811A; Coker 811.
2. Medium-season hybrids for combining early, making
silage or hogging-off early:
a. Yellow: McNair 444; Pioneer 309B; Funk G-707.
b. White: Funk G-795-W.
3. Short-season hybrids for combining early, making
silage or hogging-off early:
a. Yellow: DeKalb 805; Pioneer 310; Coker 15; Funk
G-144; US 13.
b. White: None.
B. Southern Florida:
1. Long-season hybrids for cribbing, making silage or
a. Yellow: Poey T-62; Poey T-66; Corneli 54; Funk
b. White: Poey T-23; Rocamex H-507; Rocamex
Since its release in 1948, Dixie 18 has been the
standard long-season hybrid for central, north-
eastern and northwestern Florida. It produces
high yields, stands up well, and has good weevil
resistance. Each of the other long-season hybrids
recommended is as good or nearly as good as Dixie
18 in 1 or more of these characteristics, as may
For the purpose of these recommendations, the boundary between
central and southern Florida is a line extending eastward from the
southwest corner of Hillsborough County to Vero Beach.
be seen from the following summary of field corn
variety tests for the 2-year period, 1962-1963.
% % Ear
Yield Erect Weevily Height
Hybrid Bu./A. Plants Ears (feet)
Florida 200 82.0 69 43 4.2
Coker 67 81.8 84 39 8.4
Greenwood 471 80.8 75 42 8.7
Coker 811 80.8 84 31 3.4
Dixie 18 80.4 69 38 4.8
Coker 811A 79.8 83 32 8.1
Coker 71 78.2 81 41 3.8
The medium-season and short-season hybrids
recommended for combining early, making silage
or hogging-off early are listed in order of rank
in limited variety tests. Under most conditions
only a few of these hybrids yield as well as the
recommended long-season hybrids. Because of
lower yields and higher susceptibility to damage
by insects and ear-rot organisms, the acreage
planted to medium-season or short-season hybrids
for hogging-off should not be larger than that
required to supply feed until the long-season
hybrids are ready for use.
The hybrids recommended for southern Flor-
ida are those that have performed best in variety
tests at the Everglades Experiment Station.
Plant during the planting season recommended
for the area, at times when temperature and soil
moisture conditions are favorable for germination
and growth. Recommended planting dates, by
Southern Florida ............... Feb. 1 to Mar. 20
Central Florida ................ Feb. 10 to April 1
Northeastern Florida ........ Feb. 20 to April 10
Northwestern Florida ........ Mar. 1 to April 20
To reduce the hazards of unfavorable weather,
make plantings on different dates within the plant-
ing season recommended for the area.
SPACING AND FERTILIZATION
Base spacing of plants on the inherent ability
of the soil to retain and supply moisture during
the growing season and base fertilization practices
on the spacing of plants and the nutrient levels
in the soil. Spacing and fertilization recommenda-
tions for different kinds of soil and under various
related conditions are presented in tables 1, 2
Additional information, for use in interpreting
and applying the recommendations, follows.
Soils.-The mineral soils used for corn produc-
tion in Florida are grouped, on the basis of mois-
ture capacity, as follows:
1. Soils with low moisture capacity:
a. Well-drained sands.
b. Well-drained loamy sands with sandy clay or clay
subsoils at depths more than 30 inches.
2. Soils with medium moisture capacity:
a. Well-drained loamy sands with sandy clay or clay
subsoils within 30 inches of the surface.
b. Well-drained sandy loams on sloping relief with
sandy clay or clay subsoils within 30 inches of
c. Light gray to gray imperfectly- to poorly-drained
sands, with water control where needed.
3. Soils with high moisture capacity:
a. Well-drained sandy loams on flat relief with clay
subsoils within 12 inches of the surface.
b. Light to gray imperfectly- to poorly-drained loamy
sands and sandy loams and dark gray to black
imperfectly- to poorly-drained soils, with water
control where needed.
Fertilization at Planting Time.-The fertilizer
applied at planting time on mineral soils should
be placed in continuous bands 2 to 3 inches to
either or both sides of the seed row and 1 to 2
inches below the level of the seed. If side-band-
ing equipment is not available, the fertilizer should
be mixed with the soil below the level of the seed.
The mixed fertilizer for organic soils should be
broadcast just before planting time and disked
into the soil.
Fertilization at planting time may not be neces-
sary if the immediately preceding crop was a
heavily fertilized vegetable.
TABLE 3.-RECOMMENDATIONS FOR FERTILIZA-
TION OF FIELD CORN ON ORGANIC SOILS.*
Rates of Application,
Grades of Lbs./A.
Fertilizer** Mixed Fert. as Side-
z at Planting dressing
A. ON BASIS OF SOIL-TEST RESULTS
Low 0-12-12 600-750 ............
High 0-15-10 480-600 ...........
Low 0-12-18 400-500 ............
High 0-12-12 400-500 ............
B. WITHOUT BENEFIT OF SOIL-TEST RESULTS
Years in Cult.
0 0- 8-24 400-500 ............
1 to 3 0-10-20 360-450
4 or more 0-12-12 400-500 ............
Fertilizer should contain sufficient quantities of the appropriate
carriers to supply minor elements at the following rates, in pounds
On land that has not been cropped previously: Copper
oxide (CuO), 15; manganese oxide (MnO), 10; zinc oxide
(ZnO), 5; and boric oxide (BiOs), 3.
On land that has been cropped one or more years:
Copper oxide (CuO), 5.
** Other grades of mixed fertilizer of the same ratios may be sub-
stituted on the basis of equivalent quantities of nutrients.
Side-dressing.-The side-dressing material, ex-
cept in the case of anhydrous ammonia, should
be applied 5 to 7 weeks after planting, just prior
to or at the last cultivation. Anhydrous ammonia
should be applied just after planting or at the
The nitrogen side-dressing may be reduced to
half the recommended amount where corn follows
a good growth of a winter legume.
Where corn on mineral soils follows a heavily
fertilized vegetable crop and no fertilizer is applied
at planting time, 15-0-15, 20-0-10 or similar fertil-
izer should be used as the source of the nitrogen
applied as a side-dressing.
The approximate amounts of various nitrogen
materials required to supply 20 pounds of nitro-
gen are: anhydrous ammonia, 25; ammonium ni-
trate, 60; ammonium nitrate-limestone, 98; am-
monium nitrate solution, 96; ammonium nitrate-
urea solution, 63; nitrate of soda, 125; sulfate of
ammonia, 98; and urea, 45.
To reduce or eliminate need for early cultivation
for control of weeds in the row, apply at planting
time 5/6 pound of atrazine 80w per acre, in 7 to
14 gallons of water, to a 12 or 14-inch band cen-
tered over the seed row.
For application of the atrazine, mount the
sprayer on the tractor used for planting, attach
a fan-type nozzle just behind the press-wheel of
the planter, and adjust the height of the nozzle so
that the width of the band sprayed is 12 or 14
Practice shallow cultivation, as necessary, to
control weeds until corn plants are 21/2 feet high.
Then stop cultivation. Late deep cultivation se-
verely prunes the root system and causes a re-
duction in yield.
If volunteer stands of poisonous species of crota-
laria appear after the last cultivation, apply, with
high-clearance equipment, 1/ pound of the amine
salt of 2,4-D per acre, in 10 or more gallons of
water. Use drop nozzles, putting spray on weeds
but insofar as possible keeping it off corn plants.
When using 2,4-D, read label carefully, follow
instructions and observe precautions. Do not
spray 2,4-D near sensitive crops-cotton, tobacco,
tomatoes, most garden vegetables, flowers and
ornamentals-unless air is calm or wind is blow-
ing away from the sensitive crops. Do not apply
insecticides or fungicides with sprayers used for
application of 2,4-D.
If corn is to be harvested mechanically, espe-
cially if it is to be combined, rogue fields before
harvesting is begun and remove, by hand or other-
wise, all remaining crotalaria plants. If this is
not practical, equip combine with scour-clean at-
tachment to reduce contamination of the har-
Do not harvest grain for storage until after it
has dried thoroughly in the field, unless drying
equipment is available. For safe storage, the
moisture content of the grain should not be in
excess of 15 percent for ear corn or 12 percent
for shelled corn. Metal bins used for storage of
shelled corn should be equipped with a ventilation
If crop is to be hogged-off, be sure grain has
reached the late dough stage before turning hogs
into the field. To reduce wastage, use easily mov-
able electric fences to confine herd, in succession,
to small areas, each of which will be hogged-off
completely in not more than 3 weeks.
If the crop is to be harvested for silage, cut
while grain is in the late dough or early dent stage.
CONTROL OF STORED GRAIN PESTS
Store properly dried grain in clean, rat-proof
bins that easily can be made air-tight to permit
fumigation for control of insect pests.
To reduce insect population before storing grain,
clean bins thoroughly and spray walls and floors
with 22 percent DDT, methoxychlor, or TDE
(DDD), at rate of 2 gallons per 1,000 square feet
of surface. Prepare spray by mixing 2 pounds of
50 percent wettable powder or 2 quarts of 25
percent emulsifiable concentrate into 4 gallons of
If grain is not to be fumigated apply a protect-
ant and thoroughly mix it with the grain as it is
placed in the storage bin. Use one of the follow-
ing treatments: synergized pyrethrum (0.05 per-
cent pyrethrins, 0.8 percent piperonyl butoxide,
99.15 percent talc), at rate of 10 pounds per 100
bushels; malathion dust (1 percent "premium
grade" malathion in special wheat flour diluent),
at rate of 6 pounds per 100 bushels; or malathion
spray (1 pint of 57 percent "premium grade" mala-
thion liquid concentrate in 5 gallons of water), at
rate of 1/2 gallon per 100 bushels.
Protective sprays and dusts applied to un-
shucked corn will suppress spread of weevils from
ear to ear, but will not control weevils within the
Fumigation kills the insects present at time of
treatment, but does not provide protection against
reinfestation. For proper fumigation, bins must
be air-tight, and the temperature should be above
700 F. Openly constructed storage structures
should be lined with builders' paper before grain
Immediately after filling of the storage facility
has been completed, level the surface of the grain,
close tightly all floor and wall vents, apply, with
a sprinkler can or sprayer, 1 of the mixtures
listed below, spread a tarpaulin or plastic cover
over the surface after fumigant is applied, seal
the door and attach "DANGER" sign. After 72
hours, open the door and vents and air the grain
Gals./1000 Cu. Ft.
Fumigant of Grain
1 part carbon tetrachloride plus 5 4
3 parts ethylene dichloride
4 parts carbon tetrachloride plus 5 4
1 part carbon disulfide
These and similar mixtures (1 of which is a
60-35-5 mixture of carbon tetrachloride, ethylene
dichloride and ethylene dibromide) are available
under various trade names.
Another recommended fumigant is methyl bro-
mide, at the rate of 2 pounds per 1,000 cubic feet
of grain. To apply methyl bromide, place a pan
or other receptacle on the surface of the grain
at the center of bin, put the outer end of the
tubing of the applicator in the receptacle and ex-
tend the tubing to the outside of the bin, place
an open crate or other frame over the receptacle,
spread a plastic cover over the frame and grain
surface, seal door, release gas by use of the special
applicator, and attach "DANGER" sign. After
72 hours, open the door and vents and air the
These fumigants are poisonous to man and
other warm-blooded animals. Read the label care-
fully, follow instructions and observe precautions.
FIELD CORN ACREAGES IN FLORIDA, 1959.*
County Total** Harvested Hogged-off Cut for
for Grain Silage
Alachua 31,673 16,131 15,009 533
Baker 1,593 217 1,372 4
Bradford 1,851 360 1,491
Calhoun 8,437 4,989 3,019 429
Columbia 23,796 10,257 13,369 170
Dixie 2.211 412 1,768 81
Escambia 5,923 4,229 1,573 121
Gadsden 26,120 24,279 1,741 100
Gilchrist 17,235 4,615 12,425 195
Hamilton 22,611 13,809 8,660 142
Holmes 29,255 14,437 14,700 118
Jackson 68,182 46.985 20,341 856
Jefferson 22,894 16,990 5,535 369
Lafayette 10,357 3,332 7,025 ......
Leon 12,054 10,630 954 470
Levy 15,981 7,097 8,863 21
Liberty 1,045 371 674 ......
Madison 33,709 21,439 11,616 654
Marion 18,505 6,182 8,249 4,074
Okaloosa 10,412 5,714 4,698 ......
Palm Beach 1,517 1,155 22 340
Putnam 1,253 720 256 277
Santa Rosa 19,521 13,350 5,972 199
St. Johns 1,142 965 34 143
Sumter 1,616 898 643 75
Suwannee 60,604 34,938 25,631 35
Taylor 2,585 1,073 1,512
Union 5,441 1,781 3,320 340
Wakulla 1,882 525 1,357
Walton 15,468 8,525 6,928 15
Washington 10,617 6,077 4,258 282
Others 7,628(29) 3,745(28) 2,511(19) 1,372(15)
TOTALS 493,118 286,227 195,526 11,365
From 1959 Census of Agriculture.
** Counties with fewer than 1,000 acres omitted.
t Figures in parentheses indicate number of counties.
This guide was prepared by J. R. Henderson, Agrono-
mist, and D. W. Jones, Associate Agronomist, in coopera-
tion with J. E. Brogdon, Entomologist.
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
M. O. Watkins, Director