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.
Copyright 2005, Board of Trustees, University
of Florida
Agricultural Research Center November 1982
Research Report RC-1982-6
COMMERCIAL CORN VARIETY TEST RESULTS
FROM SOUTH-CENTRAL FLORIDA, 1982
P. Mislevy, R. S. Kalmbacher, P. H. Everett and E. S. Horner-
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 their production is
low. This crop 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 also providing growing calves with quality feed.
Well managed corn harvested for silage at the proper stage of
maturity can produce 7 to 12 tons/acre of dry matter in a 3.5 to 4.0 month
period. This would allow the land to be free for the growth of other crops
during the remaining eight months.
Corn silage harvested at the hard dent stage usually contains 30 to 40%
dry matter and is high in energy, carotene, vitamin D, but low in minerals with
a protein content of about 8%. To produce hig orange,
adapted hybrids, proper seeding date, high fer il Vte R troIco ect
plant populations, and weed, insect and disease contrqjor gir q Osary.
The purpose of these studies was to evalua ..c:(~ eiV.dcidnl ds
for silage and/or grain production at Ona and Immokalee.
Experimental Procedure
The experiments were conducted at the Agricultural Research Centers
(ARC) at Ona and Immokalee. The experimental design at both locations was
1/ Professor and Associate Professor, respectively, Agricultural Research Center,
Ona; Professor, Agricultural Research Center, Immokalee; Professor,
Agronomy Department, Gainesville, Florida.
a randomized complete block with 4 replications. Twenty six commercial corn
varieties were seeded at Ona and twenty five at Immokalee. The experiment at
Ona was seeded on Ona fine sand on February 24, 1982. The Immokalee
experiment was seeded on February 8, 1982 on Immokalee fine sand.
Fertility
Fertilization practices at Ona were 920 Ib/A of 0-10-20(N-P205-K20)
prior to seeding. Nitrogen was applied at a rate of 50 Ib/A pre-emergence, and
95 Ib/A when corn plants were 6 and 24 inches tall, respectively.
At Immokalee 50-40-80 lb/A of N-P205-K20 were disked into the seedbed.
When corn was 12 and 24 inches tall 100-50-50 was applied.
Plant populations and pest control
Corn at Ona was seeded in 30 inch rows to a final population of 26,000
plants per acre. In Immokalee the corn was seeded in 30 inch rows to a
final population of 25,000 plants per acre. The herbicide practices used
at Ona were 2.0 Ib/A atrazine(active)and 2.0 Ib/A Lasso(R) (active)pre-emerge
in 35 gallons of water per acre. No cultivation practices were employed after
the corn was seeded. The insecticide Furadan(R) 10 G (2.0 lb active/A) was
applied at seeding, to control soil insects. The insecticide Mesurol(R) was
applied on the seed at the rate of 1 Ib commercial product/100 Ib seed to act
as bird repellent.
(R)
At Immokalee AAtrex(R) was applied at 2.0 Ib active/A in combination
with Lasso-R) at 2.0 Ib active/A. Mesurol(R) was applied at the same rate
used at Ona. Corn was sprayed with Lannate 1.8L(R) on 1 and 15 March
and 13 April at 2 pints/100 gal. of water to control bud worms.
Irrigation
A total of 8.7 inches of irrigation water was applied using over-head
sprinklers at the Ona ARC. The Immokalee experiment was irrigated by a
seepage system with laterals on 40 foot centers.
Maturity at Harvest
Corn was harvested when the kernels were at the hard dent stage as would
be recommended for silage production. This was coincidental with black
layer formation at base of kernel in most varieties. The experiments were
also harvested for grain. All values were converted and expressed in bushel
of shelled corn at 15.5% moisture.
Results and Discussion
Ona, ARC
Forage dry matter yields of commercial corn hybrids grown at Ona during
the 1982 growing season were excellent averaging 9.3 T/A (Table 1). These
yields ranged from a high of 12.0 T/A for the full season hybrid Northrup King
'508' to a low of 7.4 T/A for the mid-season variety Funks 'G 4740'. Because of
favorable growing conditions during the spring and the excessive moisture received
during late May and early June (21 inches in 35 days) of 1982, the corn varieties
matured about 10 to 14 days earlier. Therefore, by late June percentage dry matter
was higher for all varieties ranging from a low of 43.7% for Coker 77 B to a high of
67.6% for Acco 'UC 7251'. The ability of a top-yielding hybrid to dry down rapidly
is a very desirable characteristic. Fast dry-down indicated a variety would be
ready for whole plant harvesting (30 to 40% dry matter) sooner, allowing the
commercial grower to remove the crop before the start of summer rains. Varieties
like Ring Around 'RA 1604' and Acco 'UC 7251' contained this characteristic.
The use of early maturing hybrids like Asgrow 'RX 909' and Jacques '8220'
can also play an important role in a commercial corn program. These varieties
mature about 7 to 15 days earlier than full season hybrids, allowing one to
start harvesting sooner. This allows the grower additional time for seeding the
second crop before summer rains. Early maturing hybrids generally produce
lower dry matter yields than full season hybrids (Table 1), but grain yields and
grain to stalk ratios are good.
Grain yield is another characteristic to consider when selecting
commercial corn hybrids. Grain yields in 1982 averaged 186.9 bu/A shelled
corn @ 15.5% moisture (Table 1). The highest yielding varieties were Jacques
'247' and Ring Around'RA 1604', averaging 222.4 and 206.8 bu/A, respectively.
The lowest grain yielding varieties were 'Funks G 4507 A' and 'Funks
G4740' averaging 158 and 160 bu/A, respectively. The early maturing
Dekalb variety'XL 61' contained the lowest (23.1%) kernel moisture at
harvest. Since shelled corn should contain 13 to 15% moisture for safe storage,
the lower the moisture at harvest, the lower the energy required for drying,
consequently drying costs can be reduced by proper selection of varieties.
An important consideration when selecting corn hybrids for silage is the
grain-stover ratio. This is the amount of dried grain produced by the corn
plant in relation to total (corn stover plus grain) production. The grain-stover
ratio expresses the percentage by weight of grain available in the silage.
Producing a corn crop with a relatively high forage dry matter yield and low
grain yield (Northrup King'508') resulted in a low grain-stover ratio (44-56%)
(Table 1). Whereas Jacques'JX 247', Asgrow '909; and Dekalb'XL 61 all produced
a 70-30% grain-stover ratio. However when selecting a corn hybrid, select a
variety with a high dry matter yield, high grain yield and high grain to stover
ratio. Table I contains many excellent varieties that fit the above criterion.
Southern corn rust (Puccinia polysora) was not a problem during the
1982 growing season. However, lodging did occur during the 1982 growing
season (Table 2) partially because of a combination between excessive
moisture in late May and early June and a delayed harvest. Values found
in Table 2 are only an indication of stalk strength which was determined in
one replication.
ImmokaZee ARC
There were significant differences in dry matter yields of the 25 entries
tested (Table 3). Higher yielding entries were Dekalb '1295' (8.8 T/A), Dekalb
'XL 395 A' (8.7 T/A), Northrup King 'NK 488' (8.7 T/A) and Northrup King
'NK 508' (8.5 T/A). These were all full season hybrids and are generally
among the highest yielding entries at Immokalee. Shorter-season hybrids,
such as Asgrow 'RX 114', Coker '22', Jacques 'JX 247', etc. consistently produce
lower total yield, but have high grain yield and have the advantage of earlier
harvest, thus avoiding the rainy season.
Dry matter of all entries was higher (56.6% avg.) than that recommended
for silage production (35 to 40%) (Table 3). Higher dry matter was due to
a delay in harvest (126 days growing season). Relative differences among
the hybrids still point out differences in maturity. The higher yielding, full
season hybrids, contained more total plant moisture (about 50% DM) and more
kernel moisture (about 30%) than early hybrids (60% and 20%, respectively).
Grain yields averaged 146 bu/A and ranged from 197 to 92 bu/A (Table 3).
Better yielding entries were Golden Harvest 'H 2688' (196.5 bu/A), Jacques 'JX
247' (177.6 bu/A), McCurdy '8150' (165.5 bu/A) and Northrup King 'NK 508
(163.4 bu/A). The higher grain yielding entries are characterized by higher
grain-stover ratio (Table 3) which is indicative of higher feeding value.
The agronomic characteristics of the 25 hybrids tested at Immokalee are
provided in Table 4. Greater plant height was related to higher yield.
Lodging was only a severe problem on McCurdy 67-14 (46.3% average in 4
replications). It is not known why this hybrid lodged, but the higher lodging
was a very real response. In the previous 5 years that this entry has been
tested there has been no similar lodging problem. Disease (rust, southern leaf
blight, etc.) was very slight and uniform over the entries (2.9% infestation).
Yields of hybrids which have been tested for about five years are listed
in Table 5. It is important to consider entries that have more than a single
year of test data. Based on five years' data, Dekalb'1295', Dekalb 'XL 395
A' and Northrup'NK 508'appear to be consistently better yielding entries. With
early seeding, permitted by Immokalee's southern-most position, a full season
with early June harvest is permissible.
Conclusion
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, with a high forage dry matter percentage and
low kernel moisture percentage. A grain-stover ratio of about 50-50 or above
is desirable. If corn hybrids are grown for grain production, then high grain
yields at low kernel moisture should be selected. Selecting early maturing hybrids
allows early harvesting and seeding of another crop. Stalk strength is also an
important variable to consider when selecting corn varieties. In 1982 Ring
Around'RA 1604'and Pioneer'P 3160'were two entries which met all above
criteria at Ona. However, selected varieties out performed these varieties
in specific categories.
Table 1. Forage and grain yields and other agronomic variables
corn varieties grown at the ARC, Ona, 1982.
of commercial
Forage dry matter Grain t Kernel f Grain-stover
Brand Variety Yield At harvest Yield Moisture ratio
NK
NK
Ring Around
Coker
Acco
Pioneer
Big D
Jacques
Funks
Golden Harvest
Dekalb
Coker
Asgrow
NK
Asgrow
McCurdy
Dekalb
McCurdy
Pioneer
Acco
Funks
Asgrow
Jacques
P-A-G
Dekalb
Funks
Average
508
488
RA 1604
77 B
UC 7251
P 3160
6986
JX 247
G 4733
H 2680
XL 395 A
21
RX 114
PX 87
RX 112
67-14
XL 71
8150
3369 A
UC 8951
G 4507 A
RX 909
8220
GSX 373
XL 61
G 4740
* Means within
(-50.05) using
a column followed by the same letters
Duncan's Multiple Range Test.
are not significantly different
tBased on 15.5% moisture (shelled corn).
tDetermined at harvest.
ECalculated on oven dry basis.
Seeding date: 2-24-82
Plant population (final) : 26,000 plants/acre
Insecticide: Funadan 10 G @ 2.0 Ib/A (active) at seeding.
Row spacing: 30 inches
Fertilization: 0-92-184 Ib/A N-P2 5-K 0, respectively, preplant.
Applied 50 Ib/A N pre-emergence, 95 Ib/A N when corn plants were
6 and 24 inches tall, respectively .(R) (R)
Herbicide: Pre-emergence application of AAtrex' and Lasso at 2.0 lb/A (active),
respectively.
Harvest date: 6-22-82 (118 day season)
Irrigation: applied 8.7 inches via overhead sprinklers.
T/A
12.0
11.8
10.7
10.4
10.2
10.0
9.9
9.7
9.7
9.4
9.3
9.2
9.2
9.2
9.2
9.0
8.8
8.7
8.6
8.5
8.4
8.2
8.2
8.2
7.8
7.4
a*
ab
a-c
a-d
a-d
a-e
a-e
b-f
b-f
c-f
c-f
c-f
c-f
c-f
c-f
c-f
c-f
c-f
c-f
c-f
c-f
d-f
d-f
d-f
ef
f
d-h
e-h
ab
h
a
b-f
b-e
e-h
c-h
c-h
e-h
c-h
d-h
b-g
b-g
f-h
e-h
b-f
e-h
e-h
a-d
a-c
a-d
c-h
d-h
gh
51.0
49.9
62.8
43.7
67.6
54.8
56.9
49.3
52.4
52.6
47.1
52.9
51.5
54.3
54.3
44.9
48.5
54.4
48.3
48.5
60.1
61.8
60.4
52.3
50.6
44.5
52.9
Bu/A
173.6
184.9
206.8
189.9
165.4
192.1
198.8
222.4
188.7
201.8
175.1
193.2
190.7
192.3
184.0
203.7
179.2
200.0
197.9
179.0
158.2
190.2
166.5
183.7
179.7
160.3
186.9
b-d
b-d
ab
a-d
cd
a-d
a-c
a
a-d
a-c
b-d
a-d
a-d
a-d
b-d
ab
b-d
a-c
a-c
b-d
d
a-d
cd
b-d
b-d
d
36.4
31.7
27.4
35.6
24.9
27.2
26.5
29.4
30.5
28.7
35.3
31.1
29.2
26.0
25.1
32.3
27.9
26.6
24.3
25.3
26.6
23.8
23.8
28.6
23.1
31.4
28.4
a
c-e
f-k
ab
j-1
f-1
g-1
d-h
d-g
d-j
a-c
d-f
d-i
h-l
i-1
b-d
e-k
g-1
kl
h-1
g-l
kl
kl
d-j
1
de
44-56
47-53
59-41
55-45
49-51
59-41
61-39
70-30
59-41
67-33
58-42
63-37
62-38
63-37
62-38
69-31
62-38
69-31
70-30
63-37
57-43
70-30
63-37
69-31
70-30
68-32
62-38
c
be
bc
a-c
a-c
bc
a-c
ab
a
a-c
a
a-c
ab
ab
ab
ab
a
ab
a
a
ab
a-c
a
ab
a
a
a
9.3
Table 2. Relative stalk strength of commercial corn varieties
grown at the ARC, Ona, 1982.
Brand Variety Stalk strength
NK
NK
Ring Around
Coker
Acco
Pioneer
Big D
Jacques
Funks
Golden Harvest
Dekalb
Coker
Asgrow
NK
Asgrow
McCurdy
Dekalb
McCurdy
Pioneer
Acco
Funks
Asgrow
Jacques
P-A-G
Dekalb
Funks
Stalk strength
508
488
RA 1604
77 B
UC 7251
P 3160
6986
JX 247
G 4733
H 2680
XL 395 A
21
RX 114
PX 87
RX 112
67-14
XL 71
8150
3369 A
UC 8951
G 4507 A
RX 909
8220
SX 373
XL 61
G 4740
1= good, 1= fair, 3= poor.
Table 3. Forage and grain yields and other agronomic variables of commercial corn
varieties grown at the ARC, Immokalee, 1982.
Brand
Variety
Forage dry matter
Yield At harvest
T/A
Dekalb
Dekalb
Northrup King
Northrup King
Golden Harvest
McCurdy
Coker
Pioneer
Ring Around
McCurdy
McCurdy
PAG
Asgrow
Funks
Pioneer
Asgrow
Coker
Jacques
Funks
Big D
Dekalb
Pioneer
Funks
Jacques
Funks
Average
1295
XL 395 A
NK 488
NK 508
H 2688
84 AA
77 B
P 3160
RA 1604
67-14
8150
GSX 373
RX 909
G 4740
P 3369 A
RX 114
22
JX 247
G 4522
6986
XL 82
P 3320
G 4864
8220
G 4507 A
8.8 a*
8.7 a
8.7 a
8.5 ab
8.3 ab
8.1 ab
8.0 ab
8.0 ab
7.8 a-c
7.7 a-c
7.7 a-c
7.3 a-c
7.3 a-c
7.2 a-c
7.1 a-c
7.0 a-c
6.9 a-c
6.7 a-c
6.6 a-c
6.6 a-c
6.5 a-c
6.2 be
6.1 bc
6.1 bc
5.4 c
50.5
49.2
54.1
49.1
51.1
63.2
43.2
64.7
58.9
60.5
60.2
52.8
65.7
58.1
62.3
56.2
53.6
55.7
60.7
53.7
57.3
50.5
47.8
68.2
64.9
56.5
b-e
c-e
a-e
c-e
b-e
a-d
e
a-c
a-d
a-d
a-d
a-e
ab
a-e
a-d
a-e
a-e
a-e
a-d
a-e
a-e
b-e
de
a
ab
Grain
Yield +
Kernel
Moisture
Shelling Grain-Stover
Percentage ratio $
bu/A
148.1 bc
152.4 a-c
152.6 a-c
163.4 a-c
196.5 a
157.7 a-c
142.7 bc
143.6 be
157.4 a-c
153.1 a-c
165.6 a-c
126.5 c-d
151.4 a-c
144.4 bc
134.8 b-d
147.4 bc
156.1 a-c
177.6 ab
134.5 b-d
156.7 a-c
121.1 cd
120.4 cd
132.2 b-d
127.5 cd
92.3 d
146.2
30.8
30.5
25.3
27.4
23.7
21.1
28.8
23.1
22.4
25.0
21.9
23.3
19.8
22.4
18.6
20.2
21.9
21.8
19.9
22.9
22.8
20.9
22.8
19.8
18.2
a
a
b-d
a-c
c-f
d-h
ab
d-f
d-h
b-e
d- h
d-f
f-h
d-h
gh
f-h
d-h
d-h
f-h
d-g
d-g
e-h
d-g
f-h
h
23.0
84.8
85.3
83.9
84.9
86.4
86.8
83.2
84.8
87.3
85.6
84.6
87.5
86.4
86.6
86.8
84.5
86.7
87.4
86.9
87.7
83.9
88.2
85.8
87.8
87.3
86.0
e-i
d-h
hi
ei
a-g
a-e
i
f-i
a-c
c-h
g-i
a-c
a-g
a-f
a-e
hi
a-f
a-c
a-d
ab
hi
a
b-h
ab
a-c
46-54
47-53
45-55
51-49
64-36
51-49
47-53
50-50
56-44
53-47
58-42
47-53
58-42
57-43
50-50
56-44
60-40
72-28
54-46
64-36
48-52
53-47
57-43
56-44
46-54
54-46
d
cd
d
b-d
a-c
b-d
d
b-d
b-d
b-d
a-d
cd
a-d
a-d
b-d
b-d
a-d
a
b-d
ab
b-d
b-d
a-d
b-d
d
* Means within a column followed by the same
(P<0.05) using Duncan's Multiple Range Test.
tBased on 15.5% moisture (shelled corn).
tDetermined at harvest.
E Calculated on oven dry basis.
letters are not significantly different
Seeding date: 8 February 1982.
Plant population (final) 25,000.
Insecticide: Furadan 10G @ 2 lb/A active in row.
Row spacing: 30 inches.
Fertilization: 0-40-80 lb/A N-P 0 -K 0, respectively plus 50 lb/A N preplant; 100-50-50
when corn was 12 tall and 100-50-50 when corn was 24" tall.
Soil type: Immokalee fine sand.
Herbicide: AAtrex(R) + Lasso(R) each at 2.0 lb/A active.
Harvest date. 14 June 1982 (126 day season) .
Irrigation: Seepage with laterals on 40' centers.
--
f j
Table 4. Agronomic variables as affected by commercial corn
varieties grown at the ARC, Immokalee, 1982.
Brand
Dekalb
Dekalb
Northrup King
Northrup King
Golden Harvest I
McCurdy E
Coker
Pioneer I
Ring Around I
McCurdy 6
McCurdy 8
PA G (
Asgrow I
Funks (
Pioneer I
Asgrow I
Coker 2
Jacques J
Funks C
Big D 6
Dekalb
Pioneer I
Funks C
Jacques
Funks C
Average
Plant
Variety Height Lodging Disease
ft .% %
1295
XL 395 A
NK 488
NK 508
1 2688
4 AA
!7 B
S3160
IA 1604
;7-14
i150
;SX 373
IX 909.
3 4740
S3369 A
IX 114
!2
X 247
S4522
986
[L 82
S3320
3 4864
1220
; 4507 A
0.5
0.3
5.0
6.8
2.8
6.8
13.8
1.8
10.5
46.3
0.5
1.5
0.0
4.8
10.5
12.5
3.8
0.5
3.0
0.5
0.8
2.3
3.0
0.5
2.3
5.6
2.8
3.0
3.0
2.8
3.0
3.0
2.8
3.0
3.0
3.0
3.0
3.0
2.8
3.0
3.0
2.8
2.8
3.0
3.3
3.0
2.8
3.0
3.0
3.0
3.0
2.9
Table 5. Average forage dry matter yield of selected varieties grown at Ona and
Immokalee over the past five years, 1978-1982.
Brand Variety 1978 1979 1980 1981 1982 Average
-----------------------T/A--------------------------
ARC Ona
Coker 77
Dekalb XL 395
Funks G-4864
Funks G-5945
McNair 508 E
McCurdy 67-14
Asgrow RX 114
Funks G-4507
Average
8.5
At 11.7
9.6
9.5
8.0
t
9.8
8.9
9.4
12.2
13.0
10.5
10.5
11.3
11.8
9.6
8.3
10.9
7.4
8.1
8.8
9.3
6.9
7.2.
6.0
7.7
9.0
9.7
9.7
t
9.6
8.7
8.7
9.2
10.4
9.3
t
12.0
9.0
9.2
8.4#
9.7
10.0
10.2
9.4
9.6
10.1
9.3
8.7
8.0
9.3
ARC Immokalee
1295
XL 395 At
508-
77
67-14
G-5945
751
75-200
RX 114
9.1
8.9
8.7
8.9
9.0
9.1
7.3
7.8
6.1
8.2
9.0
8.3
7.6
8.7
8.4
7.9
6.5
8.3
8.0
7.7
8.7
8.3
6.8
7.3
6.2
6.5
5.3
5.9
6.9
entry not seeded.
entry was Dekalb XL 395
variety now called Northrup King NK 508
variety now called Coker 77'B
variety now called Funks G 4507 A.
Dekalb
Dekalb
McNair
Coker
McCurdy
Funks
PAG
McCurdy
Asgrow
Average
7.2
7.2
8.7
7.7
7.3
-4-
+
8.4
6.6
7.7
8.8
8.7
8.5
8.0 T
7.7
t
t
7.0
7.9
8.4
8.3
8.3
8.0
7.9
7.7
6.8
7.5
6.4
7.7
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