C "1,.. K' "'."" *-- t" "
TO INCREASE EFFICIENCY IN
1. Have soil tested.
2. Apply recommended kind and amount of lime-
3. Prepare a good seedbed.
4. Use good seed of hybrids that produce high
yields and are well-suited to the area and for
the use to be made of the crop.
5. Plant during the plant season for the area, at
times when temperature and soil moisture
conditions are favorable for germination and
6. Base spacing of plants on the inherent ability
of the soil to retain and supply moisture dur-
ing the growing season.
7. Fertilize on basis of plant population and soil
8. Practice shallow cultivation and lay by when
plants are 21/2 feet high.
9. Avoid contamination of harvested grain by
seed of poisonous species of crotalaria.
10. Store harvested grain in clean, rat-proof bins
and fumigate to control weevils.
UNIVERSITY OF FLORIDA
AGRICULTURAL EXTENSION SERVICE
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
6-year period 1955-1960 was more than 11/2 times
that for the preceding 6-year period 1949-1954,
and the average yield in 1960 was almost 3 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
Choose hybrids that are well-suited to the area
and for the use to be made of the crop. Recom-
mended hybrids for the different sections of the
state and for various uses are:
A. Central, Northeastern and Northwestern Florida:*
1. Long-season hybrids for grain or silage:
a. Yellow: Coker 71; Coker 67; Dixie 18; Fla. 200;
b. White: Coker 811.
2. Short-season hybrids for silage:
a. Yellow: DeKalb 633; Pioneer 309A; McCurdy 95.
b. White: None.
3. Short-season hybrids for hogging-off early:
a. Yellow: U. S. 13; Funk G-134; Funk G-50.
b. White: None.
B. Southern Florida:*
1. Long-season hybrids for grain or silage:
a. Yellow: Poey 23; Corneli 54; Funk G-740.
b. White: Rocamex H-503.
2. Short-season hybrids for silage:
a. Yellow: None.
b. White: None.
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, 1959-60.
Name of Yield % Erect Weevily Height
Hybrid Bu./A. Plants Ears (Feet)
Fla. 200 ........ 79.7 75 38 4.5
Dixie 18 ........ 79.3 78 31 4.8
Coker 811 ...... 78.7 76 39 3.8
Coker 67 ........ 78.5 78 41 3.6
Jackson .......... 77.4 75 43 4.8
Coker 71 ....... 77.1 77 34 3.6
Lee .................. 74.4 75 36 4.3
U. S. 13, which matures about 2 weeks earlier
than Dixie 18, is the highest-yielding short-season
hybrid that has been tested in Florida. The other
short-season hybrids recommended for hogging-
off early are listed in order of rank in variety tests.
Under most conditions, none of the short-season
hybrids yield as well as the long-season hybrids.
Because of lower yields and higher susceptibility
to damage by insects and ear-rot organisms, the
acreage planted to short-season hybrids for hog-
ging-off should not be larger than that required
to supply feed until the long-season hybrids are
ready for use.
The short-season hybrids for silage are recom-
mended on the basis of experience of farmers on
organic soils in central Florida.
The hybrids recommended for southern Florida
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
TABLE 1-RECOMMENDED SPACINGS AND RATES OF NITROGEN FERTILIZATION FOR FIELD CORN
ON DIFFERENT KINDS OF SOIL.
Kind of Soil Plants Spacing in Rows Rate of Nitrogen Fertilization
and per Acre* I In Mixed Fert. As
Related Conditions 3 Feet Apart 3 V Feet Apart at Planting** Sidedressing
Low moisture capacity ............
Medium moisture capacity ......
High moisture capacity ............
Organic Soils ..................................
(Pounds per Acre)
The numbers per pound for the four commercial grades of hybrid eprn seed are approximately as follows: Large round, 1,200; medium round,
1,500; large flat, 1,500; and medium flat, 1,800.
** Specific recommendations as to grades and amounts of mixed fertlizer to apply at planting time on mineral soils and on organic soils are pre-
sented in Tables 2 and 3, respectively.
TABLE 2.-RECOMMENDATIONS FOR FERTILIZATION OF FIELD CORN ON MINERAL SOILS.*
Rates of Application, Pounds per Acre
Grades of 4,976-6,223 6,223-8,297 8,297-9,957
Mixed Plants per Acrq Plants per Acre Plants per Acre
Fertilizer** Mixed Nitr gen Mixed Nitrogen Mixed Nitrogen
Fert. at as S de- Fert. at as Side- Fert. at as Side-
Planting dres ing Planting dressing Planting dressing
A. ON BASIS OF OIL-TEST RESULTS
Phosphate Potash __ _
Low 4-12-12 300-400 36 8 400-500 48-60 500-600 60-72
Low Med. 4-12- 8 300-400 36-48 400-500 48-60 500-600 60-72
High 5-15- 5 240-320 36-48 320-400 48-60 400-480 60-72
Low 5-10-15 240-320 36-48 320-400 48-60 400-480 60-72
Med. Med. 5-10-10 240-320 36-8 320-400 48-60 400-480 60-72
High 6-12- 6 200-267 36-8 267-333 48-60 333-400 60-72
Low 6- 6-18 200-267 36-48 267-333 48-60 333-400 60-72
High Med. 6- 6-12 200-267 36-8 267-333 48-60 333-400 60-72
High 8- 8- 8 150-200 36-8 200-250 48-60 250-300 60-72
B. WITHOUT BENEFIT OF SOIL-TEST RESULTS
Surface Soil ______
Sand 5-10-15 240-320 36-48 320-400 48-60 400-480 60-72
Loamy sand and
sandy loam 4-12-12 300-400 36-48 400-500 48-60 500-600 60-72
If "whitebud" is known to occur, the fertilizer should contain sufficient zinc sulfate to supply approximately 3 pounds of zinc oxide (ZnO) per
acre. For different rates of application of the mixed fertilizer, the percentages of zinc oxide required to supply 3 pounds per acre are: 200 pounds,
1.5%; 300 pounds, 1.0%; 400 pounds, 0.75%; 500 pounds, 0.6%; and 600 pounds, 0.5%.
** Other grades of mixed fertilizer of the same ratios may be substituted on the basis of equivalent quantities of nutrients.
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
TABLE 3.-RECOMMENDATIONS FOR FERTILIZA-
TION OF FIELD CORN ON ORGANIC SOILS.*
Rates of Application,
Grades of __ Lbs./A.
Fertilizer** Mixed Fert. as Side-
at Planting dressing
A. ON BASIS OF SOIL-TEST RESULTS
Low 0-12-12 600-750 .......
Low Med. 0-15-10 480-600 ............
High 0-15- 5 480-600
Low 0-12-18 400-500
Med. Med. 0-12-12 400-500
High 0-16- 8 300-375 ............
Low 0- 8-24 300-375
High Med. 0-10-20 240-300
High 0-12-12 200-250 ...........
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 (B208), 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.
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.
Spacing of Plants.-The spacings recommended
are for long-season hybrids. If short-season hy-
brids are used, the distances between the plants
in the row should be approximately two-thirds of
those recommended for long-season hybrids.
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.
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 /2 pound of simazin per acre, in 5 to 10
gallons of water, to a 12-inch band centered over
the seed row.
For application of the simazin, 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 inches.
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, 2 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 21/2 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 an
other warm-blooded animals. Read the label
fully, follow instructions and observe precaut
FIELD CORN ACREAGES IN FLORIDA, 1959
County Total** Harvested Hogged-off
__for Grain _
TOTALS 493,118 286,227 195,526 1
From 1960 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, Agron
mist, in cooperation with J. E. Brogdon, Entomologist.
Circular 144 was originally printed in January 1 .
This printing February 1961.
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