• TABLE OF CONTENTS
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 Title Page
 Table of Contents
 Preface
 Growth requirements
 Special cultural methods for peat...
 Special cultural methods for sandy...
 Fertilizer requirements
 Seed requirements
 Field insect control
 Diseases
 Bird depredations
 Insect pests of stored corn
 Points to be considered in growing...
 Acknowledgments
 Literature cited
 Historic note






Group Title: Bulletin - University of Florida. Agricultural Experiment Station ; 582
Title: Field corn production in South Florida
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Full Citation
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Permanent Link: http://ufdc.ufl.edu/UF00027429/00001
 Material Information
Title: Field corn production in South Florida
Series Title: Bulletin University of Florida. Agricultural Experiment Station
Physical Description: 44 p. : ill. ; 23 cm.
Language: English
Creator: Green, Victor E
Publisher: University of Florida Agricultural Experiment Station
Place of Publication: Gainesville Fla
Publication Date: 1957
 Subjects
Subject: Corn -- Florida   ( lcsh )
Genre: government publication (state, provincial, terriorial, dependent)   ( marcgt )
bibliography   ( marcgt )
non-fiction   ( marcgt )
 Notes
Bibliography: Bibliography: p. 44.
Statement of Responsibility: Victor Green, Jr. ... et al..
General Note: Cover title.
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Bibliographic ID: UF00027429
Volume ID: VID00001
Source Institution: University of Florida
Rights Management: All rights reserved by the source institution and holding location.
Resource Identifier: aleph - 000926790
oclc - 18282664
notis - AEN7490

Table of Contents
    Title Page
        Page 1
    Table of Contents
        Page 2
    Preface
        Page 3
        Page 4
    Growth requirements
        Page 5
    Special cultural methods for peat and muck soils
        Page 6
        Page 7
        Page 8
        Page 9
        Page 10
    Special cultural methods for sandy soils
        Page 11
    Fertilizer requirements
        Page 12
        Page 13
        Page 14
        Page 15
    Seed requirements
        Page 16
        Page 17
        Page 18
        Page 19
        Page 20
        Page 21
        Page 22
        Page 23
        Page 24
    Field insect control
        Page 25
        Page 26
        Page 27
        Page 28
        Page 29
    Diseases
        Page 30
        Page 31
    Bird depredations
        Page 32
    Insect pests of stored corn
        Page 33
        Page 34
        Page 35
        Page 36
        Page 37
        Page 38
        Page 39
        Page 40
        Page 41
    Points to be considered in growing corn in South Florida
        Page 42
    Acknowledgments
        Page 43
    Literature cited
        Page 44
    Historic note
        Page 45
Full Text


February 1957


UNIVERSITY OF FLORIDA
AGRICULTURAL EXPERIMENT STATIONS
JOSEPH R. BECKENBACH, Director
GAINESVILLE, FLORIDA





Field Corn Production in

South Florida

VICTOR E. GREEN, JR., W. T. FORSEE, JR.,
WALTER H. THAMES, JR., and F. T. BOYD


Fig. 1.-Air photo of a corn fertilizer experiment on Everglades peaty
muck soil near Belle Glade.


Bulletin 582












CONTENTS
Page
PREFACE .......................... ..................................... 3
GROWTH REQUIREMENTS ..................... ................... .. 5
Climate ......... ...... ............................. 5
Soil ................................... ......... ...................... 5
M moisture ................................................ ..... ................................. ...... 6
Seed .... ... ............-............ .......... ............ .. .................. 6
SPECIAL CULTURAL METHODS FOR PEAT AND MUCK SOILS........................... 6
Seedbed Preparation .................................. .... .......- ......- 6
W after Control .............. ........ ....... .... .......... ... ......... 6
Row and Drill Spacings ......................... ............................... 7
Time of Planting ....................................... ....... .. ...... 9
SPECIAL CULTURAL METHODS FOR SANDY SOILS ......................... ............... 11
FERTILIZER REQUIREMENTS ................-............ ....-..........-....- 12
Organic Soils ................................................................. 12
Sandy Soils ............................................................................................. 15
SEED REQUIREMENTS ........................................................... 16
Seed Treatment .......... ......... ................... ....................... 16
Seed Selection ............................................. ..................... 17
Varieties .............................. ........ ........ .......................... 17
Fall Planting ............................................................................... 21
W hite Corn ..................................... ..... .............................. 23
Hybrid Seed Corn Production for South Florida ................................. 24
FIELD INSECT CONTROL .--............... --............. .. .................. 25
Caution in Using Insecticides ......................... ................ 25
W irew orm s ....................................................... ..................................... 25
Cutworms ................................... ....... 27
Lesser Cornstalk Borer .................... ..... ..................................... 28
Fall Armyworms budwormss) ................................. .................. 29
Corn Earworms ..........- ....... ..................... ........... .......... .. 29
DISEASES .......... .................................................. ............................ 31
BIRD DEPREDATIONS ..................................................................... 32
INSECT PESTS OF STORED CORN -................ ........................ 33
Control ....................... .............. .................. 39
Part I. Recommended Procedures ................ .................. 39
Part II. Insecticides and Fumigants ........................................ 40
POINTS TO BE CONSIDERED IN GROWING CORN IN SOUTH FLORIDA................ 42
ACKNOWLEDGMENTS .............. .......................................... 43
LITERATURE CITED .................................. ............................. ........ ....... 44














PREFACE
This bulletin is a result of coordinated
research at the Everglades Experiment Sta-
tion, Plantation Field Laboratory and Indian
River Field Laboratory. The sections on
special cultural methods for peat and muck
soils, seed requirements, bird depredations,
diseases and the checklist for corn growing
were contributed by Victor E. Green, Jr.,
Associate Agronomist, Everglades Station,
Belle Glade. Sections on field insect control
and on the insect pests of stored corn were
prepared by Walter H. Thames, Jr., formerly
Assistant Entomologist at the Everglades
Station. The fertilizer requirements of field
corn on organic and sandy soils were out-
lined by W. T. Forsee, Jr., Chemist in Charge,
Everglades Station. N. C. Hayslip, Entomol-
ogist, Indian River Field Laboratory, Fort
Pierce, was active in the experiments con-
ducted at that location on the fertilizer re-
quirements of corn growing on sandy soils.
Special cultural methods for sandy soils were
contributed by F. T. Boyd, Associate Agron-
omist at the Plantation Field Laboratory,
Fort Lauderdale.








































Fig. 2.-Growth response of field corn on Everglades peaty muck to soil applications of phosphate. Left, 0-0-16 fertilizer;
right, 0-12-16 fertilizer.









Field Corn Production in South Florida

VICTOR E. GREEN, JR., W. T. FORSEE, JR.,
WALTER H. THAMES, JR., and F. T. BOYD

About 15 million dollars are spent each year on corn and
other feeds brought into Florida. More information on cultural
practices is making corn production more profitable in south
Florida. Continued progress along these lines should greatly
reduce expenditures for imported corn and feedstuffs.
This publication presents information on cultural practices,
varieties, insect control and general information on handling
the corn crop in the field and in storage. Both these aspects are
highly important for successful production of field corn.

GROWTH REQUIREMENTS
Climate.-Although corn is thought to be indigenous to the
American tropics, little has been done until recently to improve
the crop in such areas. Most of the work has been done in the
temperate zone. The problem is complex in tropical areas be-
cause of many diseases and insects that constantly attack the
crop, both in the field and in storage.
Corn yields best when grown under conditions of long days
combined with abundant sunshine. These conditions do not
usually prevail in south Florida during the summer. During
this season, skies are often overcast. June 21, the longest day
of the year, is only 13.9 hours long at Belle Glade. The high rel-
ative humidity and heavy dews occurring almost every night are
favorable to the development of leaf diseases. The summer
crop is sometimes subjected to winds of gale or hurricane force.
Tropical varieties of corn grow tall and lodge easily, unless they
are adequately bedded for protection against the wind. Tropical
varieties also require up to twice as long to mature as varieties
adapted to the Corn Belt. When planted in January or February,
they are subjected to injurious rains as they approach maturity.
This causes the grain to rot or lose its viability, or both, unless
varieties with long, tight husks are planted. .
Soil.-Corn will grow in a wide variety of soils, provided they
are properly drained and well supplied with nutrients. Optimum
pH is between 5.5 and 6.5. The fertilizer requirements of corn
are described below. Descriptions and land-use maps for soil
in the Everglades region are available in published form (6).






6 Florida Agricultural Experiment Stations

Moisture.-Abundant moisture should be present in the soil
and the ground surface should be firm when seeds are planted
to insure even germination and a rapid growth of the plants so
that the field may be weeded without delay. The water control
program on land to be planted to corn should include adequate
provision for both drainage and irrigation (1).
Seed.-The cheapest insurance for a satisfactory corn crop
is good, treated seed. It should be treated with a suitable insec-
ticide and fungicide, sacked and stored under refrigeration at
low humidity.

SPECIAL CULTURAL METHODS FOR PEAT AND
MUCK SOILS
Seedbed Preparation.-The soil should be prepared well in
advance of planting. It should be in good tilth and be free of
weeds and large amounts of raw, undecomposed organic mate-
rials. Where the surface is very rough, the soil should be gone
over with a landplane or leveler to make it smooth and firm.
Water Control.-The soil should contain operative mole drain
channels. Ditches, too, should be operating well to prevent wa-
ter from standing on the field. This will usually obviate the
necessity of planting on beds. Non-uniform soil with low, im-
pervious pockets should be bedded before planting, while level
soils are usually hilled or bedded during cultivation.
Experience at the Everglades Station has shown that yields
are inversely related to rainfall during the months of April, May
and June. That is, the lower the rainfall during these months,
the higher the yields of corn. Corn should be planted early so
that it has good growth before these rains. Between 1932 and
1940, Tuxpan corn was planted each January at the Everglades
Station. As shown in Figure 3, there was an almost perfect
negative correlation between the high yields and low rainfall
during the months of April, May and June.'
Highest yields of corn on organic soils were obtained when
the water table was kept between 24 and 30 inches below the
soil surface. When the water was within 12 to 18 inches of the
surface, the plants matured more slowly and unevenly and yields
were lower.

1 All yields of corn in this bulletin are recorded as bushels per acre of
U. S. No. 2 (15.5% moisture) shelled corn.







Field Corn Production in South Florida


In. Rainfall During Bu./A.of Tuxpan Corn
Apr, May, June

I e\r= -.916""


1936 -


'32 -

'39 -

'34 -

'37 -

'35 -

'40 -


Lull


'38 I
I I I 1 i 9 i
30 20 10 0 10 20 30 40 50
Fig. 3.-Relation between rainfall and yields of Tuxpan corn at the Ever-
glades Experiment Station, 1932-1940, inclusive.

Row and Drill Spacing.-The organic soils of the Everglades
will support more plants per acre than sandy soils. In early
experiments with open-pollinated Tuxpan, corn yielded best on
organic soils when plants were allowed two to three square feet
per plant (Figure 4).
Figure 5 shows that yields of Big Joe, a multilined synthetic
variety, are affected by the spacing of plants, much like those

1800
1600
I 1400 .
L 1200
E 1000 / .
0
S800 -
W 600
400
200
0
0 I 2 3 4 5 6 7 8 9 10 12 14 16 18
Number of Square Feet per Plant
Fig. 4.-Influence of rate of planting on yields of Tuxpan corn planted
January 19, 1939, at Belle Glade.







Florida Agricultural Experiment Stations



O


S-01



Fig. 5.-Yields of Big


90 r


80



70
.70
o
>-


2 3 4 5 9
Number of Square Feetper Plant
Joe corn at Belle Glade in 1944 as affected by plant
population and spacing.


0 3.0' Rows
S o "X D.


A *


-. ~.J I~vuw3
x 4.0' Rows


^^^ x


50 L
1.0 2.0 3,0 4.0
Number of Square Feet per Plant
Fig. 6.-Yields of Corneli 11 (Cuba M-11) corn at Belle Glade in 1953 as
affected by plant population and spacing.


100



80


60
m
to
*" 40



20







Field Corn Production in South Florida


of Tuxpan. However, yields of Big Joe were higher than those
of Tuxpan. Yields on the wide-spacing plots were affected by
a low plant population. Yields did not increase rapidly above a
population of 19,360 plants (2.25 square feet per plant). The
small yield increase obtained by using 24,200 or 29,040 plants
(1.75 and 1.50 square feet per plant, respectively) is not worth
the risk of root lodging or the extra load of stalks that must go
through the mechanical harvester. Hill dropping instead of
drilling the seed usually helps to prevent lodging.
The effect of row width and drill spacing on yields of Corneli
11 (Cuba M-11) (Fig. 6) shows there was little difference in
yields between 3-foot rows and 31/2-foot rows. Both, however,
gave higher yields than rows 4 feet apart. When using 4-foot
rows, seed placed 6 inches apart gave higher yields than where
the stand allowed either 3 or 4 square feet per plant.
Results of a more recent experiment with Corneli 54 are
shown in Table 1.

TABLE 1.-POPULATION TEST WITH CORNELI 54 FIELD CORN,
BELLE GLADE, 1955.
Row Plants I Area/Plant Plants/ Yields, Lodging
Spacing per Hill Spacing I Sq. Ft. Acre Bu/Acre* Percent
3' 1 9" 2.25 19,360 96.4 10
3' I 1 12" 3.00 14,520 76.6 9
3' 2 24" 3.00 14,520 80.8 9
6' 1 6" 3.00 14,520 65.2 13
6' 2 12" 3.00 14,520 69.6 17
6' 3 18" 3.00 14,520 69.0 8
L.S.D. 38 rows (.05) = 16.2 bu.; (.01) = 22.4 bu.
L.S.D. 6' rows (.05) = 8.5 bu.; (.01) = 11.8 bu.

From the data in these tests, it is suggested that 2 to 3
square feet should be allowed per plant. Spacing rows 42 inches
apart and plants 9 inches apart will give 2.6 square feet per
plant and 16,590 plants per acre.
Type of equipment to be used in planting, cultivating, spray-
ing and harvesting must be taken into consideration to choose
the proper width of row. Use Table 2 to check the number of
plants per acre with various row and drill spacings.
Time of Planting.-Between 1934 and 1939, 16 varieties of
open-pollinated corn were planted each month from November
through May. Satisfactory yields were obtained only from the
January and February plantings. The data are shown graphic-
ally in Figure 7. Hybrid corn is no different in this respect, as






30


25


20


m 15
a,

" 10


5


0


Mar. Apr. May


Month Planted
Fig. 7.-Influence of time of planting on average yields of 16 varieties
bf open-pollinated corn in south Florida. Six-year average (1934-39) at
Belle Glade.
120r


1951
---- 1952
------1953


20-


Jan. Feb. Mar. Apr. May
Fig. 8.-Influence of dates of planting on average yields of hybrid corn
at Belle Glade-10 varieties in 1951, 27 in 1952 and 8 in 1953.


Nov. Dec. Jan. 'Feb.


100F


401







Field Corn Production in South Florida


shown in Figure 8. January plantings gave highest yields.
Yields dropped rapidly in plots planted from February to April.
For each day's delay in planting after February 15, it is esti-
mated there is a loss in yield of about one bushel per acre.

TABLE 2.-CORN PLANTING TABLE FOR DRILL WIDTHS, SPACING,
AND SEED REQUIRED.
Plants I No. Plants Sq. Ft. Area I Seed Required/A
per Hill Spacing per Acre per Plant Approx., Lbs.
Three Feet Between Rows

1 9" 19,360 2.25 17.3
1 12" 14,520 3.00 13.0
2 18" 19,360 2.25 17.3
2 24" 14,520 3.00 13.0
Three and One Half Feet Between Rows

1 9" 16,590 2.62 14.8
1 12" 12,445 3.50 11.1
2 18" 16,590 2.62 14.8
2 24" 12,445 3.50 11.1
Four Feet Between Rows

1 6" 21,780 2.00 19.4
1 9" 14,520 3.00 13.0
1 12" 10,890 4.00 9.7
2 12" 21,780 2.00 19.4
2 18" 14,520 3.00 13.0
2 24" 10,890 4.00 9.7

SPECIAL CULTURAL METHODS FOR SANDY SOILS
The agricultural sandy soils of south Florida are suitable for
corn production provided adequate fertilization and water con-
trol measures are used. There should be optimum soil moisture
at planting time and during the growing season to produce uni-
form germination and steady growth. Preliminary information
indicates that a water table 24 inches below the soil surface is
best for such crops, once the stand has been established. The
upward movement of soil water by capillarity is not enough to
permit good seed germination when the water table is at the 24-
inch level. For this reason, preparation of seedbeds by flat culti-
vation has been found most satisfactory for sandy soils.
After the corn seedlings emerge, it is necessary to deepen
the middles to give adequate aeration and protection against
flooding. Low spots in the field should be drained with cross
ditches, or "quarter-drains". Middles or ditches between the






Florida Agricultural Experiment Stations


beds should be connected with other ditches in the field drain-
age system.
There are advantages to bedding or ridging up the corn row
after seedling emergence. First, nutrients are thrown nearer
the plant roots. Second, by improving soil drainage, conditions
are more beneficial for root growth, the threat of root rot dis-
eases is not as serious, amounts of beneficial nitrifying bacteria
and oxygen are increased, and weed competition is lessened.
The mechanics of the ridging process may vary with differ-
ent farmers. It appears easier to grow two rows of corn on each
ridge. One pair of rows 30" apart on each bed with a distance
of 72" between beds will make cultivating and spraying easier.
Fertilizers are more easily applied in soil on the top of the bed
between the 30-inch rows than to single rows.
Sandy soils with 14 to 15 thousand plants per acre of adapted
varieties give good yield performance if adequate fertilizer and
moisture are available.

FERTILIZER REQUIREMENTS
The practice of following fall and winter plantings of heavily
fertilized vegetable crops with spring plantings of field corn
fills a definite need in a general farm management and crop ro-
tation program. But a grower should not assume that this land
does not need supplemental applications of fertilizer for his corn.
Such ideas often lead to crop failures or reduced yields that could
have been prevented by using more fertilizer.
Organic Soils.-Fertilizer tests (2,3) on peat and muck soils
in the Everglades have indicated a need for potash and phos-
phate, as well as certain minor elements. Requirements for
virgin organic soils are usually higher than for soil previously
cultivated and fertilized. Virgin Everglades peat and muck soils
should receive a broadcast application of 12 pounds of copper
per acre. This may be supplied effectively as 25 pounds of 50
percent copper oxide or 50 pounds of 25 percent copper sulfate
(4). The copper may be applied separately or in the mixed fer-
tilizer if it is broadcast. Initial applications of copper to virgin
soils are most effective if applied at least two weeks before
seeding crops that are subject to copper deficiency during early
stages of growth, tests show.
The mixed fertilizer usually recommended for corn on virgin
organic soils is 500 to 600 pounds per acre of 0-8-24 containing
3.0, 2.0, 1.2 and 0.7 percentages of CuO, MnO, ZnO and B203,






Field Corn Production in South Florida


respectively. The CuO may be omitted if it has been applied
separately. Broadcast applications are recommended for virgin
soils because it is best to have the fertilizer ingredients, espe-
cially copper, distributed throughout the root zone. Also, the
heavy applications usually required are less likely to "burn" the
roots if the fertilizer is broadcast. Because of the high ex-
change capacity of these soils, there is little danger of leaching
when fertilizer is applied several weeks before planting.
Most field corn in the Everglades is planted in fields under
cultivation one or more years. Therefore, research on fertility
requirements of this crop has been directed mainly at deciding
amounts of fertilizer needed to supplement nutrients remaining
in the soils from earlier fertilizer applications. Experiments
have indicated that optimum levels of phosphate and potash
for best crop development usually may be obtained from appli-
cations on old vegetable land of 0 to 400 pounds 0-12-12 per acre.
The formula and rate per acre can be determined more accurately
from soil sample tests.
Nitrogen applications at levels up to 50 pounds N per acre
have been included in experiments with phosphate and potash.
In no cases have significant growth or yield responses been
obtained.

TABLE 3.-GROWTH AND YIELD OF FIELD CORN AS INFLUENCED BY METHOD
OF APPLICATION OF CERTAIN FERTILIZER MIXTURES.
Fertilizer Formula Fertilizer Distri- Av. Height of I Yield,** Bu.
Applied at 800 Lbs./A. bution Method Plants*, Inches per A.
No fertilizer .................. 22 72
6-6-16 .............................. Broadcast 31 87
6-6-16 ................................ Band 36 95
3-12-16 ....................... Broadcast 37 95
3-12-16 ............................. Band 38 98
6-12-8 ................................ Broadcast 36 98
6-12-8 ............................. Band 39 95
6-12-16 .... ..................... Broadcast 36 91
6-12-16 .....--............._.--. -.. Band 37 93

Height measurements made about 6 weeks after seeding.
L.S.D. (.05) = 4; (.01) = 6.
** L.S.D. (.05) = 12; (.01) = 16.

Experiments conducted on peat soils under cultivation for
approximately 10 or more years indicate that band applications
are better than broadcast. Table 3 shows the comparative effects
on growth and yield of band and broadcast applications of cer-







Florida Agricultural Experiment Stations


tain fertilizer mixtures. These data represent a part of the
previously described experiment in which marked responses to
phosphate applications were obtained. Increase in growth re-
sponse to band over broadcast methods was significant only at
the lower phosphate level, six percent P20s. In all cases, how-
ever, corn with band applications of fertilizer grew slightly bet-
ter, averaging 38 inches in height for all band treatments as
compared to 35 inches for the broadcast treatments. The effect
of applied phosphate on the height of corn is shown in Figure 2
(page 4). Where phosphate was applied, the plants were more
vigorous and healthy.
Observations with corn and other crops on the older peat
soils have indicated that the response to band over broadcast
applications may be due primarily to a more efficient use of
applied phosphate. Table 4 shows the main and interaction
effects of various levels of phosphate treatments made as band
and broadcast applications on the growth of field corn. In all
cases where phosphate was applied, band applications promoted
more growth than did broadcast, with all differences being sig-
nificant. There was a response to as little as 150 pounds per acre
of 20 percent superphosphate applied in bands, whereas 600
pounds applied broadcast were required to show response.

TABLE 4.-EFFECT OF RATE AND METHOD OF APPLICATION OF P205 DERIVED
FROM SUPERPHOSPHATE ON GROWTH OF CORN AS DETERMINED BY PLANT
HEIGHT (IN INCHES) ABOUT SIX WEEKS AFTER SEEDING.
S Application Method
Fertilizer Treatment Application Method-
Pounds 20% Bandt I Broadcastt I Average*
Superphosphate/Acre Plant Height in Inches _
0 42 42 42
150 49 42 46
300 51 41 46
450 51 42 47
600 52 46 49

Average ** 49 1 43_
L.S.D. (.05) = 3.
** L.S.D. (.01) = 2.
t L.S.D. (.05) = 4.

As a result of these and similar experiments, it is recom-
mended that, except for virgin peat soils, fertilizer applications
be made in bands at time of seeding. Corn seedlings are easily
damaged by fertilizers applied too near the seed, so care must
be taken in placing the fertilizer bands. Where soil tests show
a need for more than 300 pounds per acre of a mixture contain-







Field Corn Production in South Florida


ing more than 10 percent KO2, it is recommended that phosphate
be applied in bands. Then apply most of the potash broadcast
or as a side-dressing.
Sandy Soils.-Satisfactory yields of corn on the sandy soils
of south Florida cannot be obtained without using fertilizers.
Heavy rains during the summer months usually remove by
leaching most of the nitrogen and potash. Thus, even on areas
that previously have been heavily fertilized for vegetable crops,
comparatively heavy applications of nitrogen and potash are
required for a corn crop the following year. Approximately
120 pounds N, 100 pounds P205 and 100 pounds K20 per acre
are recommended. To insure these amounts, apply at seeding
time 800 pounds per acre of 4-12-6 and follow with two side-
dressings of 12-0-6 at 400 pounds each.
Fall plantings of tomatoes and other heavily fertilized veg-
etable crops are often harvested in ample time for the grower
to plant a late winter and spring crop of corn before heavy, leach-
ing rains come. Such a rotation program allows economical use
of large amounts of residual fertilizers. Experiments conducted
on Immokalee fine sand to determine the fertility requirements
of spring crops of field corn following fall crops of tomatoes (5)
have indicated a need for only nitrogen. No responses have
been obtained from phosphate or potash applied at seeding time
or as a side-dressing. Table 5 shows the yields of corn as in-
fluenced by nitrogen applications to crops growing on sandy soils

Fig. 9.-Growth response of field corn on Immokalee fine sand to soil
applications of nitrogen. Left 30 and right 90 pounds N. per acre.







Florida Agricultural Experiment Stations


immediately following fall crops of tomatoes. Most of the ap-
plied nitrogen was derived from soluble sources. Results re-
ported under "Experiment 2" are averages of yields from three
sources: nitrate of soda, ammonium nitrate and urea. No yield
differences were obtained where different sources of soluble
nitrogen sources were used.
Figure 9 shows the growth response to nitrogen applications
represented by the 30- and 90-pound treatments for Experiment
1A reported in Table 5. Experiments and other observations
have indicated that most of the applied nitrogen should be side-
dressed in two or more applications.

TABLE 5.-EFFECT OF NITROGEN APPLICATIONS ON CORN GROWING ON
IMMOKALEE FINE SAND.
Nitrogen
Application Yields, Bushels per Acre
Lbs. per Acre Expt. 1A* Expt. 1B* Expt. 2**
30 46 41 -
40 42
60 53 50 -
80 45
90 66 59 -
120 52
L.S.D. (.05) 7 9 3
Yields of A, Big Joe, and B, Dixie 18, planted on the same area at the same time.
** Big Joe Variety.

SEED REQUIREMENTS
Seed Treatment.The main reasons for treating corn seed in
south Florida are to control wireworms and seed rots caused by
fungi. Fungi, attacking the seed between time of planting and
germination, cause serious skips in the stand. Seed treatment
for wireworm control is covered in the Field Insect Control sec-
tion of this bulletin. Seeds sold by commercial supply houses
usually have been treated with a fungicide only. The tag on the
bag will state this and name the material used. Home-grown
seed must be treated annually by the grower himself or by a
business concern that has a dust or slurry treater. Mercurial
compounds should be applied to seed corn just before planting.
Otherwise, germination may be reduced. Fungicides recom-
mended for treating seed corn include Spergon, Dow, 9-B, Arasan,
Phygon and Delsan. All these are non-mercurials. Directions
on the manufacturer's label should be followed explicitly to in-
sure proper seed treatment and to prevent hazards to individuals
using the chemicals.






Field Corn Production in South Florida


Seed Selection.-Seed corn should be selected from mature,
healthy, ears after they are dry. Picking and shelling moist
corn results in damage to the germ. Even when kernels are
dry, the grain must be handled with care from picking to plant-
ing time. Air temperature of the dryer should not exceed 1100
F. in the pile of corn. The grain should be dried to about 15
percent moisture, then shelled, graded, and stored under refrig-
eration at low humidity to insure high germination and seedling
vigor. Insect damage is minimized in cold storage (380-420 F.).
Once seed is in cold storage it should be left there until just be-
fore planting. Refrigerated seed removed from refrigeration
loses viability more rapidly than seed not subjected to low tem-
peratures.
Seed of open-pollinated varieties can be saved for planting if
grown away from other corn. Two varieties are White Tuxpan
and Cuban Flint. Synthetic varieties, Big Joe, for example, will
lose vigor and yielding ability if just a particular type ear is
selected, such as for color, shape or ear length. Concentrate
just on choosing mature, healthy ears, regardless of other char-
acteristics. Succeeding generations of hybrid varieties yield
less, because the first crossing of inbreds to form single crosses
imparts maximum vigor. However, double-crossed seed are
cheaper to produce, and retain enough vigor to yield profitably.
Varieties.-An ideal variety of corn sprouts quickly, grows
vigorously, tassels early, makes a short stalk with low ears,
resists insects and diseases, has a long, tight husk, resists lodging
and breaking, matures relatively early and gives a high yield of
solid corn.
A variety satisfying all these requirements does not exist
for south Florida. Newer releases are coming closer to the ideal,
however. As previously stated, tropical corn varieties are by
nature tall, with ears high on the stalks. As stalks have been
shortened, yields have dropped. Inbreeding in the tropics leads
to a loss of most vigor within three generations.
To obtain a quantitative measure of the effect of stalk height
on yield of tropical lines, two experiments were conducted in
'1953, using 34 lines from the Guatemala Tropical Research Cen-
ter of Iowa State College at Antigua, Guatemala, and 43 lines
from the Rockefeller Foundation at Mexico City. Seeds were
planted on February 14 in three-foot rows. The stand was
thinned to one plant per foot, or 14,520 plants per acre. The
grain was harvested when mature. The data presented in







Florida Agricultural Experiment Stations


Figure 10 show that there is a definite correlation between tall
stalks and high yields. Note also that the two groups represent
two ranges of yields-the taller Guatemalan varieties out-yield-
ing the shorter ones from Mexico.

110
/21 Corn from Mexico r 0.506"
Corn from Guotomolo, r-0.693**
90


70
-0o


50


30


10
5 6 7 8 9 10 II 12
Stalk Ht., Ft.
Fig. 10.-Relationship between stalk heights and yields of 36 Guatemalan
and 43 Mexican corn varieties at Belle Glade in 1953.

In 1936, highest yield of corn at the Everglades Station was
23 bushels per acre. Selections were made from the open-polli-
nated lines then existing and two years later yields had risen
to 38 bushels. By 1940, hybrid corn production in the southern
United States had made progress. Some of these hybrids were
planted at Belle Glade. The best plots yielded 66 bushels per
acre. These were Louisiana hybrids containing Tuxpan lines
that originated in Mexico. Seed of the variety, Mayorbela, were
imported from the Puerto Rico Experiment Station in 1942.
This variety was produced there by crossing a local variety from
Isabela with the best S5 line, and then submitting the cross to
mass selection. It produced 73 bushels per acre, more than any
other variety then grown in south Florida. The variety is un-
excelled for resistance to the species of fungi causing Helmin-
thosporium leaf blights. It resists lodging, yields exceptionally
well, and has sound, flinty ears usually free of weevils. Ma-
turing ears do not tend to rot or germinate in the field, because






Field Corn Production in South Florida


they have good husk coverage. For the first time since the Ever-
glades was opened for agriculture, it was possible to recommend
a variety for planting that would give a satisfactory yield, even
under adverse conditions.

1201 Go


1940 1945


1950 1953


Year
Fig. 11.-Trend in maximum yields at the Everglades Experiment Sta-
tion, 1936-1953. A, Open-pollinated varieties; B, improved open-pollinated
varieties; C, introduction of hybrid varieties; D, Mayorbela from Puerto
Rico; E, Big Joe synthetic; F, better spacing and population; G, additional
tropical crosses and improved agronomic practices.

Because of its desirable characteristics, Mayorbela was used
in combinations that would give heterosis and permit the release
of seed to growers in the shortest possible time. This was ac-


20O
1935






Florida Agricultural Experiment Stations


complished by synthesizing new varieties by multiple top-cross-
ing, using Mayorbela as the-female parent. Crosses were made
in the fall of 1942 and the spring and fall of 1943, and the first
crosses incorporated into replicated tests for yielding ability.
This work was performed by Dr. Roy A. Bair, assistant agron-
omist at that time.
The synthetic chosen for increase was made by crossing the
following lines: (White Tuxpan x Cuban Yellow Flint x Yellow
Tuxpan) x Mayorbela. The resulting variety was named "Big
Joe". In 1944, growers planted 1,000 acres of this variety.
Yield tests at the Experiment Station showed that 113 bushels
per acre could be obtained if recommendations were followed
closely. An educational program was necessary to prevent the
loss of vigor of advanced generation seed by ear selection of a
particular type as already discussed.


6 Big Joe
FG-737

Yel. Tux. C-;Corneli
Mayorbelao I__,_ ______x F-Funk
4Agro.Sem.

S ITGY
0 12

FG-715
FG-721
Dixie 18
C-54
FG-740
I FG-737A
Red F.E
Cub. Flint
20 30 40 50 60 70 80 90 100
Yields, Bu./A.
Fig. 12.-Yields of yellow corn varieties at Belle Glade, 1952-54.

From 1940 until the present, workers in the Pan-American
countries have cooperated in furnishing inbred lines, single and
double crosses, and synthetic varieties for testing by the Ever-
glades Station. The Agronomy Department at Gainesville also
has cooperated in the incorporation of these lines into crosses.







Field Corn Production in South Florida


One such cross yielded at the rate of 120.6 bushels per acre
in 1953.
The history of the corn improvement program is represented
graphically in Figure 11, showing yields of corn at the Ever-
glades Station from 1936 to 1953. Figure 12 depicts the aver-
age yields of 19 varieties of yellow field corn that have been
tested six times, two varieties five times, three varieties four
times, two varieties three times, four varieties two times and
five varieties tested only once. However, Corneli 54 will prob;
ably replace C-11, C-12 and C-13 on the market because its char-
acteristics are superior.
Fall Planting.-Corn is sometimes planted in the fall as an
emergency crop. At that time of year, the days are short and
temperatures become lower as growth proceeds. Seedlings are
almost always stunted by the heavy rains in September and
October. Land planted to fall corn is not available for January
or February planting, since it takes about six months to mature
a fall crop. To make the land available earlier for the following
crop, the plants can be cut and fed while in the milk stage.

TABLE 6.-YIELDS AND SHELLING PERCENTAGE OF NINE CORN VARIETIES
PLANTED ON SEPTEMBER 10, 1951 AT BELLE GLADE, FLORIDA.

Variety Shelling Percentage Yields, Bu./Acre*

Corneli 11 (Cuba M-11)............ 84.5 41.0
Funk G-737 ................. ......... 80.1 31.0
Big Joe ........................ ... .... 83.7 30.8
Agroceres Sementes (Brazil).... 83.0 24.8
Francisco Flint ............................ 80.8 24.3
W hite Tuxpan .............................. 83.4 23.1
La. 2509 ................................. ..-: 81.9 17.4
Cuban Flint .................................. 82.4 9.4
Florida W -1 ................... ............ 81.8 8.7

*L.S.D. (.05) = 8.8 Bu.; (.01) = 11.6 Bu.

On September 10, 1951, an experiment was begun to test the
yielding ability of 10 varieties in the fall months. Yields and
shelling percentages are shown in Table 6. The highest yielding
variety was Corneli 11 (Cuba M-11), a double cross hybrid pro-
duced through the cooperative efforts of the Corneli Seed Com-
pany of Cuba and the Estacion Experimental Agronomica at
Santiago de las Vegas, Havana, Cuba. This hybrid was released
to Cuban growers in April 1951, after five years of experimenta-
tion. In Cuba, it had outyielded the older Cuban varieties by


























CORNELI II (CUBA M-ll)

Fig. 13.-Typical ears of Corneli 11 (Cuba M-11).


Fig. 14.-Typical ears of Corneli 54.







Field Corn Production in South Florida


25 percent. As shown in Figure 10, the average yield of Corneli
11 for six plantings in the spring of 1952, 1953 and 1954 was
81.3 bushels per acre. Typical ears of this variety may be seen
in Figure 13, while Figure 14 depicts ears of Corneli 54.
In 1952 another fall corn test was started. Seed were dropped
in three-foot rows. The stand was thinned to two plants every
15 inches, giving 16,336 plants per acre. The test included three
new accessions from Cuba. The corn was harvested February
8, 1953. Corneli 11 outyielded all other varieties, as shown in
data in Table 7.

TABLE 7.-YIELDS OF CORN PLANTED IN THE FALL OF 1952,
BELLE GLADE, FLORIDA.

Variety Yields* Variety Yields

Corneli 11 .............. 43.6 Tiquisate 31.5
Corneli 13 .... 36.1 Agro. Sem. 31.2
Funk G-715 ............ 35.3 Big Joe 30.6
Corneli 12 ..__.......... 34.6 Mayorbela 19.2
Cuba SC-10 ............ 33.9 Yellow Tuxpan 16.7
Francisco Flint .... 33.9 Dixie 18 16.1
Funk G-737 ............ 33.8

*L.S.D. (.05) = 2.7 Bu.; (.01) = 4.3 Bu.

From these two tests, it appears that a grower should choose
Corneli 11 as the variety best adapted for fall planting.
White Corn.-White varieties of field corn are in demand for
the manufacture of white grits and cornmeal. Although they
are lower in vitamin A content, white corn products are preferred
by many people. Most of the white varieties are dent corns.
At present there is no white flint variety adapted for south Flor-
ida. Husk coverage is generally inferior in the white varieties,
quality of the grain is poor at harvest, yields are very low and
keeping quality of the grain is usually very poor.
The present breeding program at the Everglades Station in-
cludes the quest for superior white hybrids. Figure 15 shows
the average yield of white varieties during the past several years.
Compare this with Figure 10. Notice that only two varieties
of yellow corn had an average yield below 40 bushels per acre
and only one variety of white corn averaged more than that.
The Guam variety, although grown only two times, is better
adapted to the climate of south Florida than other white vari-
eties. At Belle Glade, Guam grows about 71/2 feet tall and has
ears about 4 feet from the ground. Eight to 14 rows of very







Florida Agricultural Experiment Stations


61 White Tux \\\ \\
FG-791W
FG-785W
S.4 La. 521
0 Texas 9W
Texas IIW
o La. 468
z 3 Ga.281
SWhatleys
Fla. W-I
2lGuam \\\\\\ \\\\\\\\\\\\\\\ \
0 10 20 30 40 50 60 70
Yields, Bu./A.
Fig. 15.-Yields of white corn varieties at Belle Glade, 1951-54.
large kernels line each ear. The variety is only moderately re-
sistant to leaf blights.
Hybrid Seed Corn Production for South Florida.-In 1955 a
goal in corn production was reached for this area-for the first
time a seed company offered its services for the production of
hybrid seed. The Experiment Station is equipped only for the
production of inbred lines and testing of crosses to measure com-
bining ability, yields and resistance to diseases and lodging.
Enough seed to plant 15 acres of single crosses were supplied
by the Corneli Seed Company of Cuba. This was planted by two
local growers for the production of the double-cross hybrid, Cor-
neli 54. This variety is the newest of a number of hybrid vari-
eties (Corneli 11, 12, 13 and 31) released in Cuba that are well
adapted to south Florida conditions.
Corneli 54 is superior to the other varieties, having more
uniformity in stalk and ear height and better resistance to insect
damage in the field and in storage. The stalks average 9 feet
tall, with ears about 5 feet above the ground. The husk cover-
age is superior, preventing the entry of rain water and insects.
The ears average about 7 inches in length and are characterized
by 14 to 18 rows of straight kernels on a medium-sized cob. The
kernels are deep, flat and very flinty. They are deep orange, with
bright yellow caps. Tip fill is usually good. The plants are
straight, have a good brace root system and resist lodging and
breaking. The variety is fairly resistant to leaf blights. The
average yield for 1954 and 1955 on experimental plots planted
the first week in February on three-foot rows with stalks one
foot apart was 88.5 bushels per acre.






Field Corn Production in South Florida


FIELD INSECT CONTROL

Caution in Using Insecticides!.-Insecticides are neces-
sary for corn production-and for its protection in storage.
However, they are poisonous to humans and must be used
with care. There is no hazard if the materials are properly
used. Follow these rules carefully:
1. Read the manufacturer's label.
2. Do not breathe dust or vapor, or get insecticides or
fumigants on the skin.
3. Wear protective clothing, gloves and approved respi-
rators or gas masks if the label suggests their use.
4. Bathe and change to clean clothes daily when ap-
plying insecticides.
5. Wash hands and face before smoking or eating.
6. Bury or burn empty insecticide containers, or punc-
ture to prevent re-use.
7. Do not apply more often or at higher dosages than
recommended.
8. Familiarity through common use of insecticides will
often result in a careless attitude on the part of spray crews.
Be sure they continue to observe safety rules.


Controls outlined here are adequate under average conditions
of infestation in the area. More severe infestations, or failure
to initiate controls at the proper time, will require more applica-
tions and increase the cost.
Wireworms.-Figure 16 shows a wireworm of the species
that attacks corn in south Florida. Wireworms are the young
of click beetles. They hatch during March to July from eggs de-
posited in the soil by the female beetles. The larvae feed on
roots in the soil for about 9 to 10 months, after which they enter
the pupa stage, transform to adults and emerge to deposit more
eggs.
The principal wireworm pest of the area is the corn wire-
worm (Melanotus communis Gyll.), which attacks the seeds, roots
and shoots of corn. Larvae grow to be about 11/2 inches long be-
fore pupating. Smaller larvae are white to cream colored. Larg-
er larvae are amber to brown, very hard and round. They are
usually about 1/2 inch long when they start causing damage.






Florida Agricultural Experiment Stations


Late plantings often are not as severely damaged as earlier
plantings because the larvae have completed the feeding stage
by late March or April.
Wireworms move about freely in the soil in search of food.
Points to remember in controlling them are:
1. Prepare land three to four weeks before planting.
2. Apply insecticide
as a broadcast spray
three weeks before
planting. Disk in top
four to six inches of soil.
3. Use a spray rig
with nozzles adjusted to
approximately 12 inches
above ground level. Use
enough nozzles to give
complete coverage over
the swath with little
overlapping. A d j u s t
pressure to less than 200
pounds to avoid fogging
and drift of fine parti-
cles.
4. Determine how
many acres are to be
sprayed a n d calculate
how many gallons per
acre will be applied by
the rig, with the nozzles,
pressure and tractor
0 'speed to be used for the
Fig. 16.-Taproot of cornstalk cut to application.
show large wireworm and damage caused 5. A p p ly 3 to 4
pounds of actual aldrin
or heptachlor or 4 to 6 pounds of chlordane per acre. Use an
emulsifiable concentrate formulation. The label states the num-
ber of pounds of "actual" per gallon of concentrate.
6. If the spray rig as prepared for this job has been found
to deliver 67 gallons per acre, for example, then mix 3 pounds of
aldrin or heptachlor (11/2 gallons of a 20-25 percent emulisfiable)
in every 67 gallons of water in the tank. If the sprayer delivers
110 gallons per acre, then add 3 pounds for each 110 gallons.







Field Corn Production in South Florida


The amount of water is not important. The important thing is
to know how much water will be applied per acre in order to get
the proper amount of insecticide in the tank.
7. Do not let the sprayer get more than one "round" ahead
of the disk. Have disk working on upwind side of sprayer so
the disk operator will not be hit by spray drift.
8. Inspect nozzles often to see that all are working.
9. Apply lindane, 25 percent wettable, at 8 ounces per 100
pounds to the seed
before planting.
Cutworms.-Two
species inhabit t he
Everglades: the
black cutworm, Agro-
tis ypsilon Rott., and
the granulate cut-
worm, Feltia subter-
ranea (Fab.). Pre-
paring land at least
one month before
planting will reduce
the number of cut-
worms. These worms
can crawl across
ground to newly
planted fields. The
soil treatment given
for wireworms is not
usually effective for
cutworms. A preven-
tive treatment may
be applied just be-
fore the corn comes
Fig. 17.-Lesser cornstalk borer. The larva
up. Use 21/, pounds has been removed from its protective webbing
of 40 percent wet- which can be seen extending from the base of
the plant. Top half inch of soil removed to re-
table toxaphene or 1/4 veal webbing.
pound of actual al-
drin or heptachlor per acre in 50 to 100 gallons of water. For
dust applications, use 25 pounds of a 10 percent toxaphene dust.
Inspect young corn frequently. This helps to detect an in-
festation early. If damage is found, use one of the treatments
suggested above, or use a poison bait made of 21/ pounds of






Florida Agricultural Experiment Stations


technical toxaphene in 971/2 pounds wheat bran at the rate of
20 to 30 pounds per acre. Apply bait in the evening. Cutworms
feed chiefly at night and the dew will keep the bait moist.
Lesser Cornstalk Borer.-The larvae of this insect, Elasmo-
palpus lignosellus Zell., are small, greenish-blue worms with
bands of darker colors. They may attack the young corn stalk
just beneath the surface. Figure 17 shows a larva slightly
larger than natural size. Two silken tubes covered with par-
ticles of soil may be seen extending away from the base of the
plant. The larva is usually inside one of the tubes or else in the
stalk. The layer of soil over the tube was removed before the
picture was taken.
At times these worms occur in great abundance, causing se-
vere loss of stand. Control is difficult; once an infestation is well
established, insecticides are of little value. If damage is occur-
ring in the area, some protection may be obtained by applying
1/2 pound of actual heptachlor or aldrin as a spray to the base
of very young plants just as they push through the ground.
Repeat the application after seven to 10 days. Delay cultivation
and thinning as long as possible.


Fig. 18.-Whorl opened to show budworm and feeding damage on develop-
ing tassel.







Field Corn Production in South Florida


Fall Armyworms.-The larva of this insect, Laphygma frugi-
perda (J. E. Smith), is also called the budworm, or sometimes
the grassworm. The eggs are laid in clusters on the under sides
of the leaves. The larvae emerge and feed on the leaves for a
time, removing the green portion but leaving the clear upper sur-
face of the leaf intact. They crawl into the bud or whorl, feeding
downward toward the developing tassel. When fully grown the
larvae are about 11/ inches long. Figure 18 shows a budworm
exposed to view by opening the bud down to the newly formed
tassel.
Budworms should be controlled when young by applying 1
quart of 25 percent DDT emulsion or 21/2 pounds of toxaphene
wettable powder in 50 to 150 gallons of water per acre. The
amount of spray is increased as the corn grows. Direct the
spray into the whorls of older plants. Wet the foliage of
younger plants thoroughly. Detecting infestations early and
spraying promptly are important, for then expensive spray
schedules will not have to be maintained.
Fall armyworms also attack the ears after the tassels mature.
In cases of severe infestation, it may be economical to apply 30
to 40 pounds per acre of a 5 percent DDT dust by airplane after
the tassels emerge and before the silks appear to keep worms
from migrating to the ear.
Corn Earworms.-Maize is the preferred food of the corn
earworm (Heliothis zea Boddie). A considerable amount of
damage is caused by larvae feeding on kernels. Other damage
results from entry of other insects, such as rice weevils, into the
holes left in the husks when the earworm emerges to pupate.
Fall armyworms also cause damage of this nature.
Because of the high cost, control with insecticides is not
usually practicable. If control is deemed advisable, a mixture
of 3 quarts per acre of 25 percent DDT emulsion with 13% gallons
of a white mineral oil of 65 to 95 Saybolt viscosity may be ap-
plied in 50 gallons of water. Use about 100 pounds pressure,
directing the spray at the silks. Apply the spray three times
at three-day intervals, starting two days after the first silks
appear. Dusts are too expensive at silking time, since six or
eight applications should be made at 24-hour intervals to be
effective.
Important! Corn stalks treated with DDT should not be
used for forage because of the residue.
Some varieties of corn have more resistance to earworms







Florida Agricultural Experiment Stations


than others. Several factors contribute to this resistance, one
being the extension of the husk beyond the tip of the ear. Corn
varieties are being evaluated for earworm resistance and some
hybrids are showing much promise. Table 8 shows some vari-
eties rated according to the amount of damage done by corn
earworms in 1954.

TABLE 8.-EARWORM DAMAGE INDEX WITH RESPECT TO CORN VARIETIES.

Variety Damage Index* Variety Damage Index

Francisco Flint .. 121 Mayorbela 179
Corneli 54 ............ 123 Dixie 18 204
Corneli 12 ............ 134 Funk G-715 209
Yellow Tuxpan .. 149 Funk G-737 226
Corneli 13 ............ 162 Cuban Flint 238
Corneli 11 .......... 164 Funk G-714A 239
Big Joe ..---....... 169

L.S.D. (.05) = 30.5.
L.S.D. (.01) = 40.5.
Average of four replications of a trial planted February 1 and harvested July 7, 1954
at Belle Glade. Low index numbers indicate less damage to the ears.

DISEASES
Diseases of field corn in south Florida thus far have not been
widespread. Probably this is because only varieties of tropical
parentage are grown commercially. Through natural selection,
the lines in these tropical varieties apparently have acquired
some resistance to diseases.
Currently, profits from field corn do not justify the cost of
chemicals to control diseases. Therefore, the breeding programs
are aimed at finding disease-resistant lines of corn. Cooperative
work is being carried on with the Crops Research Division,
ARS, U. S. Department of Agriculture, and informally with the
Pennsylvania State University and the Crow Hybrid Corn Com-
pany, Milford, Illinois. In this joint work, promising lines are
selfed and crossed by all the agencies, resulting in two crops of
corn being grown each year.
South Florida's moist, warm climate, augmented by heavy
dew nearly every night and the high-nitrogen organic soil in the
Everglades, make corn more susceptible to disease. The leaf
blight diseases attack the varieties before full bloom anthesiss).
This eliminates the need for selfing susceptible lines (Figure
19). Therefore, the number of lines in a breeding program can
be held to a minimum by discarding a number of them before




































Fig. 19.-Above: corn leaves of young plants showing infection with Northern leaf blight (Helminthosporium turcicum). At
right: Northern leaf blight lesions on leaves of maturing corn plant.






Florida Agricultural Experiment Stations


full bloom. This is usually not possible in the Corn Belt, where
lines do not show susceptibility until after anthesis.
On organic soil, corn varieties most resistant to Northern
and Southern leaf blight are:

Inbreds .....................Connecticut 103 and Ohio 4-C
Single Crosses ...-.....Crow 1100 x C-103 and Crow 1200 x C-103
Three-way Crosses....Corneli 12
Double Crosses ........Corneli 11, Corneli 13, Corneli 54 and
HDEE1(3330A).

BIRD DEPREDATIONS
Damage by birds, such as pulling up sprouts and feeding on
maturing grain, has been studied at Belle Glade by Mr. Robert
T. Mitchell of the Fish and Wildlife Service, Department of the
Interior.2 The best way of protecting ripening grain from birds
is to use a .22 rifle, his investigations show. However, firearms
are too dangerous to use except in isolated places. Every pre-
caution to avoid injuring people or livestock in nearby fields
should be taken.
Next to rifles, the scare device is the rope-firecracker as-
sembly. It consists of sections of cotton plowline along which
firecrackers are arranged at various intervals. The fuses are
inserted between the rope strands, and sections are suspended
from supports throughout the field. These devices are lighted at
the free-hanging end. As the rope slowly burns, the fuse of
each successive firecracker is ignited. The firecracker drops to
the ground and explodes. Excellent results in scaring off birds
have been obtained by using this device every 360 feet.
Whichever method is used, good protection will result only
by starting early in the game. When birds begin to show inter-
est in the crop and before they become used to coming to the field
to feed is the time to start. Use the scare device early each morn-
ing as the birds fly in from their night roosts (7).
Meadow larks and grackles are notorious for sprout pulling.
Blackbirds do most damage to ripening corn. Corn maturing in
late winter from a fall crop is more likely to be eaten by redwings
than a crop maturing in summer.
Corn ears damaged by birds are shown in Figure 20. The
shredded husks leave the ear open to insects and rain.

; Mitchell, Robert T. Instructions for the Use of Firecrackers to Pro-
tect Corn from Blackbirds in the Florida Everglades Area. Everglades
Station Mimeo Report 54-2. May 1, 1954.







Field Corn Production in South Florida


Experiments at the Everglades Station include study of
varieties to determine the nature of resistance to birds. The
breeding program includes this factor in selecting adapted vari-
eties. Yet, when birds number 500 to the acre, even Francisco
Flint, which has a long, tight husk with as many as 14 layers,
may be badly damaged.


Fig. 20.-Remains of an ear of Francisco Flint corn. The husks, nor-
mally long, plentiful and tight, have been completely stripped and shredded
and every grain was eaten in the soft dough stage by redwings.

Fall-planted corn should be harvested as soon as it matures
to shorten the time it is exposed to birds.

INSECT PESTS OF STORED CORN
A number of insects attack corn in storage in the South.
Two principal ones are the rice weevil, Sitophilus oryza (L.),
and the Angoumois grain moth, Sitrotroga cerealella (Oliv.).







Florida Agricultural Experiment Stations


Fig. 21.-Emergence holes left in husks by corn earworms and f-ll army-
worms provide points of entry for other insects and for fungi.


Fig. 22.-The five ears of corn in Fig. 21 with husks removed. Note weevil
damage to three center ears.







Field Corn Production in South Florida


Both of these enter the ears in the field and have opportunity to
cause great loss unless they are controlled.
These pests often have access to the ear through holes left
in the husk by emerging corn earworms and fall armyworms.


Fig. 23.-Corn may be held in this type storage for short periods only
and should be removed to tight bins and fumigated if it is to be kept for
more than one or two months.







Florida Agriuculturat Experiment Statzons


Figures 21 and 22 show five ears selected at random from a bin
of corn. Emergence holes of corn earworms may be seen in the
husks in Figure 21. Note the damage caused by rice weevils in
the area near the holes of the husked ears in Figure 22.


R-<'_ r- "


Fig. 24.-Another method of storing corn for short periods only.

If corn is to be stored on the farm, it is necessary to have
proper facilities. Corn cannot be protected in open storage,
nor can it be fumigated to kill pests in the ear unless tarpaulins
are used. Corn to be fed to cattle soon after harvest may be
stored temporarily in structures such as those shown in Figures
23 and 24. But for storage over longer periods, tighter bins are
































Fig. 25.-Bins of this type provide better protection for corn. They are
designed to permit good air circulation from artificial dryers and may be
made tight enough for effective fumigation.






Fig. 26.-A larger storage building with blower in place. With careful
construction there should be very few openings for loss of fumigants or
entry of moisture.


Now,, --


-"BML







Florida Agricultural Experiment Stations


needed (Figures 25 and 26). These bins provide proper air cir-
culation to permit drying, and may be closed for fumigating.
Figure 27 shows the interior of the storage bin shown in Figure
26. Note the A-shaped tunnel in the foreground and the wire
mesh wall to the left.
The following U. S. Department of Agriculture Publications
which may be obtained through your County Agent should be
consulted:


Fig. 27.-Interior view of the structure shown in Fig. 26. The false
wall and floor hold corn away from the sides and off the floor. Warm dry
air blown into the A-shaped tunnel escapes through the corn to the sides
and up to the hatches on top.







Field Corn Production in South Florida


Farmers Bulletin 2009, Storage of Small Grains and Shelled
Corn on the Farm.
Farmers Bulletin 2010, The Storage of Ear Corn on the
Farm.
Leaflet 331, Drying Shelled Corn and Small Grain with
Heated Air.
Leaflet 332, Drying Shelled Corn and Small Grain with Un-
heated Air.
Leaflet 333, Drying Ear Corn with Heated Air.
Leaflet 334, Drying Ear Corn with Unheated Air.
These may be obtained from your County Agricultural Agent
or from the Office of Information, U. S. Department of Agricul-
ture, Washington 25, D. C.
Every corn grower should obtain these publications because
they give information on preserving corn.

CONTROL 3
PART I.-RECOMMENDED PROCEDURES
1. Prevent field infestation.
a. Clean premises before corn begins to silk by:
(1) Destroying trash and crop residues from bins, etc.,
where insect pests may be living.
(2) Fumigating grain to be held over (see section under
fumigation).
(3) Spraying bins (see section under bin sprays).
b. Plant adapted varieties with long, tight husks.
c. Harvest early, as soon as corn is dry enough to store, or
dry the corn if facilities are available.
2. Provide safe storage.
a. Select dry bins, protected from weather. Insects are at-
tracted to high-moisture corn, breeding in it faster than
in dry grain.
b. Clean bins. Remove all trash and crop residues, spray
bin walls to destroy insects hiding in cracks and tunnels
(see section under bin sprays).
c. Make the bins rodent- and bird-proof by means of shields
and screening.

3 Prepared and approved by a conference of State and Federal Research
and Extension Entomologists, sponsored by the Cotton States Branch,
Entomological Society of America at New Orleans, La., February 11, 1953.






Florida Agricultural Experiment Stations


3. Inspect stored corn.
a. Inspect stored corn once a month.
b. Turn heated corn or corn out of condition, and artificially
dry if possible.
4. Apply insect control measures.
a. Fumigation is a very effective method of killing insects
in stored corn, providing the corn is stored in tight bins.
Fumigate at temperatures high enough to make insects
active (see section under fumigation).
b. Protectant dusts (see section under protectant dusts).
(1) Seed corn. Seed corn can be completely protected by
DDT or methoxychlor dusts or slurries. Seed corn
so treated should not be used for feed or milling.
(2) Feed corn. Synergized pyrethrum dusts are effective
for several months in preventing insect damage in
uninfested or very lightly infested shelled or husked
ear corn. Such dusts will suppress spread of weevils
from ear to ear in unhusked corn, but will not control
weevils within the unhusked ears.
c. Treated bags. Insect-free grain may be satisfactorily
protected against stored-grain insects for several months
by storing in bags made of cloth treated with pyrethrins
alone or synergized pyrethrins. The finished cloth should
contain 10 milligrams of pyrethrins per square foot.

PART II.-INSECTICIDES AND FUMIGANTS
1. Bin sprays.
The entire inner surfaces of storage bins should be sprayed
after cleaning and before the corn is stored. Use one of the
following formulations:
a. DDT, 21/2 percent applied at the rate of 10 gallons per
1,000 square feet of surface area.
b. Methoxychlor, 21/2 percent applied at the rate of 10 gal-
lons per 1,000 square feet of surface area.
c. TDE, 21/2 percent applied at the rate of 10 gallons per
1,000 square feet of surface area.
Note: The above materials are available as wettable pow-
ders or concentrated emulsions. Add 10 pounds of
50% wettable powder to 5 gallons of water, or 1/2
gallon of 25% emulsifiable concentrate to 4 gallons
of water to make 21/2 percent dilutions.







Field Corn Production in South Florida


d. Pyrethrins or allethrin, 0.5 percent applied at the rate of
2 gallons per 1,000 square feet of surface area.
Note: Synergized pyrethrins and synergized allethrin
spray formulas are available. Evidence at hand
is insufficient to determine the rates at which these
mixtures may be substituted for the above 0.5 per-
cent emulsions. If used, follow manufacturers'
recommendations.
2. Fumigants.
a. 80-20 mixture of carbon tetrachloride and carbon disul-
fide applied at the rate of 5 gallons per 1,000 cubic feet
in steel bins or 61/4 gallons in wooden bins.
b. 75-25 mixture of ethylene dichloride and carbon tetra-
chloride, applied at the rate of 6 gallons per 1,000 cubic
feet in steel bins or 7.5 gallons in wooden bins.
c. 60-35-5 mixture of carbon tetrachloride, ethylene dichlor-
ide and ethylene dibromide applied at the rate of 5 gal-
lons per 1,000 cubic feet in steel bins or 6.5 gallons in
wooden bins.
d. Carbon disulfide applied at the rate of 3 gallons per 1,000
cubic feet.
Caution: When used in the pure form, carbon disulfide
is highly explosive. Take extreme caution to keep
the fumes away from flames, sparks or excessively
hot surfaces.
e. Methyl bromide applied at the rate of 1 pound per 1,000
cubic feet.
Caution: Methyl bromide fumes are toxic to humans and
animals. Caution should be observed to prevent
exposure to it.
3. Protectant dusts.
a. DDT or methoxychlor, applied at the rate of 1 ounce of
3 percent dust per bushel of seed. A slurry can be made
by adding 2 ounces of 50 percent wettable powder to 1
gallon of water. This will treat about 30 bushels of seed.
Caution: These mixtures should be used on seed corn only.
b. Synergized pyrethrum (0.05 percent pyrethrins, 0.8 per-
cent piperonyl butoxide, 99.15 percent talc), applied at
the rate of 100 pounds or more per 1,000 bushels, or 1
pound per 10 bushels.






42 Florida Agricultural Experiment Stations

POINTS TO BE CONSIDERED IN GROWING A CROP
OF CORN IN SOUTH FLORIDA

I. Sixty to 90 days prior to planting:
1. Establish water control-ditching and diking.
2. Initiate preliminary land preparation-uprooting of large
growth and chemical or mechanical destruction of wild growth in
the field.
3. Plow the area to initiate decomposition of plant residue.
4. Disk at intervals to reduce recurrent growth of vegetation.
5. Place orders for seed, insecticides, firecrackers and shot-
gun shells to insure local stocking of such materials.
6. Repair, adjust and maintain power equipment, planters,
cultivators and spray rigs.

II. Fifteen to 30 days prior to planting:
1. Take soil samples for chemical analysis and fertilizer
recommendations.
2. Complete the final water control plan which will involve
the construction of quarter drains on sandy soils and mole-drain-
ing peat soils.
3. Do any necessary disking to destroy plant growth and
prevent buildup of insect populations.
4. Smooth the soil surface with any of the conventional im-
plements.
5. Treat the soil for wireworms three weeks before plant-
ing.

III. Within a week of the planting date:
1. Apply fertilizer to virgin organic soils, including minor
elements at the recommended rate.
2. Insure that seed have been treated with suitable fungi-
cide and insecticide.
3. Adjust water table to proper depth to insure sufficient
moisture for germination.
4. Select row width and drill spacing. See that the proper
plates and gears.are on hand for use in the planter to give the
desired spacing.







Field Corn Production in South Florida 43

IV. During the planting operation and for the next 21 days:
1. Make sure the planter is drilling fertilizer and dropping
seed uniformly and that seeds are covered and packed. This will
insure a more rapid, even germination and will reduce damage
by birds.
2. After planting, pre-emergence insecticide treatment can
be applied.
3. Check the planted areas each day for evidence of seed or
sprout pulling by rodents and birds. If necessary, take protec-
tive measures.
4. Check the planted areas each day for evidence of cutworm
or lesser cornstalk borer damage to the sprouted corn. If nec-
essary, treat with recommended insecticides.

V. During the growth of the crop until lay-by time:
1. Inspect the crop for evidence of injury by budworms (fall
armyworms). When necessary, use the suggested insecticide
treatments.
2. Cultivate to control weeds as necessary. Just before the
corn plants are tall enough to reach the toolbar on the tractor,
move soil from the middles to the rows of plants to protect them
from root lodging. This is a necessary operation on all soils of
south Florida.
3. Maintain a suitable water table during the growth of
the crop.

VI. From lay-by time until after harvest:
1. Practice sanitation measures in the storage facilities as
outlined.
2. When grain seems nearly mature, take samples for mois-
ture determination. Harvest promptly as soon as moisture con-
tent is at or below 22 percent.
3. Dry the product to be stored to about 15 percent moisture.
Apply insect control measures as outlined.

ACKNOWLEDGMENTS
The authors wish to acknowledge the help of C. E. Seiler, E. E. Archer
and T. E. Pennington, who assisted in the collection of field data, and G. E.
Averill and H. M. Spelman, III, for the photographs. The graphs were
drawn by E. King, Jr.







Florida Agricultural Experiment Stations


LITERATURE CITED

1. CLAYTON, B. S., J. R. NELLER, and R. V. ALLISON. Water Control in the
Peat and Muck Soils of the Florida Everglades. Fla. Exp. Sta.
Bul. 378. 1942.
2. FORSEE, W. T., JR. Utilizing Soil Tests as a Basis for the Determina-
tion of Optimum Levels of Phosphate and Potash for Crops Growing
on Everglades Peat and Muck Soils. Proc. Soil Sci. Soc. Fla. 13:
124-130. 1953.
3. FORSEE, W. T., JR., V. E. GREEN, JR., and R. H. WEBSTER. Fertilizer
Experiments with Field Corn on Everglades Peaty Muck Soil. Soil
Sci. Soc. Amer. Proc. 18: 76-79. 1954.
4. FORSEE, W. T., JR., T. C. ERWIN and A. E. KRETSCHMER, JR. Copper
Oxide as a Source of Fertilizer Copper for Plants Growing on Ever-
glades Organic Soils. Fla. Expt. Sta. Bul. 552: 5-16. 1954.
5. FORSEE, W. T., JR., and N. C. HAYSLIP. Fertility Requirements of Field
Corn Grown on Sandy Soils Following a Fall Crop of Unstaked
Tomatoes. Proc. Fla. State Hort. Soc. 56: 148-153. 1954.
6. JONES, LEWIS A., et. al. Soils, Geology and Water Control in the Ever-
glades Region. Fla. Exp. Sta. Bul. 442. 1948.
7. NEFF, JOHNSON A., and ROBERT T. MITCHELL. The Rope Firecracker.
Wildlife Leaflet 365. U. S. D. I.-F. W. S. Washington, April 1955.









HISTORIC NOTE


The publications in this collection do
not reflect current scientific knowledge
or recommendations. These texts
represent the historic publishing
record of the Institute for Food and
Agricultural Sciences and should be
used only to trace the historic work of
the Institute and its staff. Current IFAS
research may be found on the
Electronic Data Information Source
(EDIS)

site maintained by the Florida
Cooperative Extension Service.






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