Historic note

Group Title: Commercial corn variety testing results from south-central Florida.
Title: Commercial corn variety testing results from south-central Florida. 1987
Full Citation
Permanent Link: http://ufdc.ufl.edu/UF00075790/00011
 Material Information
Title: Commercial corn variety testing results from south-central Florida. 1987
Series Title: Commercial corn variety testing results from south-central Florida.
Translated Title: Research Report - University of Florida Agricultural Research Center ; 1987-6 ( English )
Physical Description: Serial
Language: English
Creator: Mislevy, P.
Stephenson, R. J.
Horner, E. S.
Martin, F. G.
Publisher: University of Florida, Agricultural Research Center
Publication Date: 1987
 Record Information
Bibliographic ID: UF00075790
Volume ID: VID00011
Source Institution: University of Florida
Rights Management: All rights reserved by the source institution and holding location.
Resource Identifier: oclc - 143646330

Table of Contents
    Historic note
        Unnumbered ( 1 )
        Page 1
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        Page 7
Full Text


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

site maintained by the Florida
Cooperative Extension Service.

Copyright 2005, Board of Trustees, University
of Florida

, ..*7 C-

Agricultural Research and Education Center, Ona

Research Report RC-1987-6 October, 1987

P. Mislevy, R. J. Stephenson, E. S. Homer and F. G. Martin-

Corn can be extremely valuable in a livestock feeding program. With its
rapid growth and high yielding ability, corn harvested and stored as silage
can supplement perennial grasses at times when production is low. Corn may
follow winter vegetables or be used in a pasture renovation program. High
quality corn silage can provide dairy and beef cattle with a substantial
carbohydrate input, possibly reducing high grain costs and provide growing
calves with quality feed.

Corn harvested for silage at the proper stage of maturity can produce 7
to 13 t/A of dry matter in 3 to 4 months. This would allow the land to be
used for other crops during the remaining 8 to 9 months.

Corn forage harvested at the hard dent stage for silage usually contains
30 to 50% dry matter, approximately 8% crude protein, is high in energy,
carotene, vitamin D, but low in minerals. To produce high yields of quality
corn forage, adapted hybrids, proper seeding date, high fertility, water
control, correct plant populations, weed, and insect control measures are

The purpose of this study was to evaluate commercial corn hybrids for
silage and/or grain production at Ona.

Experimental Procedure

The experiment was conducted at the Agricultural Research and Education
Center (AREC) Ona. Thirty commercial corn varieties were seeded on an Ona
fine sand on March 3, 1987. The experimental design was a randomized complete
block with 4 replications.


Fertilization practices were 1020 lb/A of 0-10-20 (N-P205-K20) plus 30
lb/A F503- micronutrients prior to seeding. Nitrogen was applied at a rate
of 54 lb/A pre-emergence, and 90 lb/A when corn plants were 6 and 18 inches
and an additional 40 lb/A when corn was 2 ft tall. Soil pH was 6.0, with
adequate amounts of calcium and magnesium.

1/ Professor and Assistant Professor, Agricultural Research and Education
Center, Ona; Professor, Agronomy Department; and Professor, Statistics,
Gainesville, Florida.

SF503 contains the following elemental content: iron, 18.0%; zinc, 7.0%;
manganese, 7.5%; copper, 3.0%; boron, 3.0%; molybdenum, 0.2%.

Plant population and pest control

Corn was seeded in 30 inch rows and thinned to a final population of
27,000 plants N acre. Herbicides used were 2.3 lb/A atrazine (active) and
2.3 Ib/A Lasso (active) pre-emerge in 35 gallons of water per acre. No
cultivation practice )were employed after the corn was seeded. The
insecticide Furadan 15 G (2.7 lb active/A) was applied in 7 inch bands at
seeding to control mole crickets and bud worms on small corn. No addtional
insecticide was used for bud worm control. The insecticide Mesurol was
applied to the seed at the rate of 1 lb commercial product/100 lb seed to
repel birds.


A total of 6.7 inches of water was applied using over-head irrigation

Corn maturity at harvest

Corn plants were harvested for dry matter yield when the kernels of most
varieties were at the hard dent stage as recommended for silage production.
This was coincidental with black layer formation at the base of kernels in
most varieties. Other variables recorded for the experiment were oven dry
grain yield, forage dry matter (percent and yield), kernel moisture, shelling
percentage and grain-to-stover ratio (dry matter basis). Grain yield values
were converted and expressed in bushels of shelled corn at 15.5% moisture.

Results and Discussion

Significant (P<0.05) differences were obtained among corn varieties for
forage dry matter yield, percentage forage dry matter, grain yield, kernel
moisture, shelling percentage and grain-to-stover ratio (Table 1). Forage dry
matter yields of commercial corn hybrids grown at Ona during the 1987 season
averaged 8.3 t/A (Table 1). These yields ranged from a high of 11.8 t/A for
'Sunbelt 1876' to a low of 6.0 t/A for Conlee 202. Forage dry matter yields
for 1987 were slightly lower (0.6 t/A) than average dry matter yields obtained
in 1986. Forage yields for 1984, 1986 and 1987 were essentially the same and
average high temperatures (83 F) for March through June for these years were
also similar. However, average forage yields in 1985 were 2.5 t/A higher
along with a 3 F increase in temperature. These forage dry matter yields are
considered respectable, since commercial corn variety testing had been
conducted continuously on this same plot area for 15 consecutive years.
However, only one single corn crop is grown on this land each year. Following
the corn crop the land was allowed to grow common bermudagrass (Cynodon
dactylon L.).

Percentage forage dry matter at harvest averaged 34.4% in 1987,
indicating that plants matured slower than 1985 which averaged 42% dry matter,
both allowed to grow approximately the same number of days.

Growers should consider using some early maturing hybrids like 'McCurdy
8150', 'Asgrow RX 892' and Agratech GK 900. These entries mature relatively
early as evidenced by the higher percentage dry matter (Table 1) and have good
forage and grain yields. These varieties are generally ready for harvest by
late June, allowing crop removal prior to excessive summer rains and time for
seeding a second crop.

Grain yields in 1987 averaged 158 bu/A shelled corn adjusted to 15.5%
moisture (Table 1). The higher grain yielding varieties were 'Paymaster 8951'
and 'Sunbelt 1827' producing an average of 188 and 187 bu/A, respectively. In
1986 Sunbelt 1827 also produced significantly (P<0.05) higher grain yields
averaging 204 bu/A. This hybrid also produced high forage yields (9.0 t/A)
with a good grain to stover ratio.

When selecting corn hybrids to be harvested for silage it is important to
consider the grain-to-stover ratio. The grain-to-stover ratio is expressed
(dry wt. basis) as a percentage by weight of grain available in the silage.
Corn varieties with a relatively high forage dry matter yield and average
grain yield (Sunbelt 1876) or low forage yield and very low grain yield
(Conlee 202) result in low grain-to-stover ratios of 40-60 and 32-68%,
respectively (Table 1). Varieties that produce high grain yields, but medium
forage yields (short stalks) such as Paymaster 8951 result in a
grain-to-stover ratio of 67-33%. Therefore, it is important that commercial
growers study all agronomic variables listed in table 1 before selecting corn
varieties to be grown and consider type of animals which will be fed the
forage. One grower may prefer high grain yields, whereas another grower may
prefer maximum corn forage production per acre.

Southern corn rust (Puccinia polysora) was evident on all varieties when
plants were denting, however this late infection of rust generally has little
effect on yield. Some army worm damage (Spodoptera frugiperda Smith),
commonly called bud worm, was evident on 20% of the corn plants. Since 50% or
more of the plants need to be attacked by bud worms before it is economical to
spray, no insecticide was applied. Good bud worm control Ta obtained when
plants were 6 to 18" from the systemic insecticide Furadan applied at

Variety selection

When considering commercial corn hybrids for forage and/or grain
production in south central Florida it is desirable to select varieties that
have performed consistently well over several years. Based on these data,
'Dekalb DK 748', 'McCurdy 8172' and 'Pioneer 3192' produced a 3-yr average dry
matter yield of 10.9, 10.2 and 9.7 t/A, respectively (Table 2). If grain
production is the objective 'P-A-G SX 383', McCurdy 8172 and Dekalb DK 748
averaged 192, 191 and 189 bu/A over a 3-yr period, respectively.



When selecting a commercial corn hybrid to be grown and stored as silage
in south-central Florida, it is best to select a variety that produces high
forage and grain yields, resulting in a high (about 50-50) grain-to-stover
ratio. Varieties selected should have a high forage dry matter percentage and
low kernel moisture. If corn hybrids are grown for grain, high grain yields
at low kernel moisture are important. Varieties with low kernel moisture
indicate rapid field drying, earlier harvesting with low storage drying costs.

Some varieties that have produced high forage dry matter and grain yields
in 1987 at Ona were Sunbelt 1876, McCurdy 8150, McCurdy 8172, Dekalb DK 748,
Sunbelt 1827, Asgrow RX 892, 'Asgrow O's Gold 5509', Agratech GK 900 and
Paymaster 8951.



and grain


and other

agronomic variables

of commercial


varieties gro

Company or Forage dry matter Graint Kernel Shelling Grai
brand Variety Yield At Harvest yield moisture percentage rati

t/A % bu/A %

Sunbelt 1876 11.8 a 31.3 ed 172 a-c 44.5 a 80.0 ab 40-6
McCurdy 8150 9.8 b 36.6 a-c 177 a-c 37.0 d-i 82.4 ab 51-4
McCurdy 8172 9.4 be 33.3 b-d 179 a-c 39.2 b-f 83.7 ab 50-5
Dekalb DK 748 9.2 b-d 31.4 ed 167 a-c 40.1 b-d 82.6 ab 48-5
Northrup King PX 9646 9.1 b-d 32.1 cd 137 b-d 39.5 b-e 83.4 ab 41-5
Pioneer 3055 9.0 b-d 32.1 ed 134 b-d 40.9 be 83.1 ab 41-5
Sunbelt 1827 9.0 b-d 33.6 b-d 187 a 40.9 be 83.9 ab 54-4
Asgrow RX 892 8.8 b-e 36.5 a-c 167 a-c 35.5 g-j 85.6 ab 46-5
Funks G 4733 8.8 b-e 32.1 ed 143 a-d 36.5 d-i 83.2 ab 43-5
Asgrow O's Gold 5509 8.7 b-e 33.1 b-d 177 a-c 39.7 b-e 84.5 ab 57-4
Agratech GK 900 8.5 b-e 34.8 b-d 184 ab 37.3 c-i 81.5 ab 59-4
Seedtech H-2686 8.4 b-e 30.5 d 173 a-c 38.7 b-g 80.3 ab 59-4
Jacques JX 247 8.4 b-e 30.9 ed 162 a-d 42.2 ab 87.2 a 54-4
P-A-G SX 352 8.4 b-e 38.2 ab 154 a-d 34.2 i-k 86.8 ab 47-5
Dekalb DK 689 8.3 b-e 31.7 ed 165 a-d 38.5 b-h 87.2 a 54-4
Northrup King PX 95 8.3 b-e 31.2 ed 159 a-d 40.2 b-d 83.2 ab 55-4
Coker 8905 8.2 b-e 30.3 d 164 a-d 39.7 b-e 83.2 ab 53-4
Agratech GK 925 8.2 b-e 33.9 b-d 163 a-d 38.6 b-h 84.0 ab 52-4
Seedtech H-2775 A 8.1 b-f 34.6 b-d 159 a-d 35.4 g-j 82.5 ab 54-4
Dekalb DK 711 8.0 b-f 36.5 a-c 168 a-c 34.3 i-k 83.0 ab 51-4
P-A-G SX 383 8.0 b-f 35.3 b-d 170 a-c 36.1 e-j 85.1 ab 51-4
Agratech GK 750 7.9 b-f 36.5 a-c 135 ed 35.0 h-j 84.5 ab 45-5
Coker 21 7.7 b-f 35.3 b-d 156 a-d 40.1 b-d 84.2 ab 54-4
Northrup King PX 9581 7.5 b-f 36.5 a-c 147 a-d 35.8 f-j 84.3 ab 52-4
Conlee 113 7.5 b-f 34.4 b-d 150 a-d 37.4 c-i 82.0 ab 52-4
Paymaster 8951 7.5 b-f 32.9 b-d 188 a 34.9 h-j 83.5 ab 67-3
Asgrow RX 777 7.4 c-f 36.6 a-c 144 a-d 31.0 k 85.1 ab 55-4
Pioneer 3320 7.0 d-f 41.0 a 151 a-d 34.2 i-k 84.8 ab 60-4
Northrup King PX 9540. 6.6 ef 38.5 ab 119 d 32.8 jk 86.9 a 46-5
Conlee 202 6.0 f 41.5 a 75 e 37.4 c-i 79.3 b 32-6
AVERAGE 8.3 34.4 158 37.6 83.7 51-4



Means within a
Multiple Range

column followed


letters are not






on 15.5% moisture



tDetermined at


Expressed as a percentage

by weight

on an

oven dry



Plant D



March 3,

in (final)


27,000 plants/A



18 lb/A commercial


in 7





row at


Row spacing

30 inches






lb/A N-P 05-KO pi
d at a rate of 54

and an additional

magnesium was


us 30 lb/A F503 (R)
lb/A pre-emergence,

40 lb/A when


corn was



90 and 90 lb/

ft tall



to seeding

hen corn
pH was 6

was 6





Pre-emerge application of

Aatrex (R)

and Lasso(R)

at 2.3

lb/A active,




inches of

water via





A w

Table 2. Average forage and grain yields of selected dent corn varieties grown
at Ona for three or four years, 1984-1987.

Company or Years Forage Grain Yield
brand Variety tested dry matter 15.5% moisture

t/A bu/A

Dekalb DK 748 3 10.9 189
McCurdy 8172 3 10.2 191
Pioneer 3192 3 9.7 153
Jacques JX 247 4 9.6 168
Northrup King PX 95 4 9.5 167
Asgrow O's Gold 5509 3 9.5 168
Agratech GK 925 4 9.4 173
P-A-G SX 383 3 9.4 192
McCurdy 8150 4 9.4 177
Coker 21 4 9.3 174
Paymaster 8951 4 9.2 171
Funks G 4733 4 8.8 150

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