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Group Title: Commercial corn variety testing results from south-central Florida.
Title: Commercial corn variety testing results from south-central Florida.1983
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 Material Information
Title: Commercial corn variety testing results from south-central Florida.1983
Series Title: Commercial corn variety testing results from south-central Florida.
Translated Title: Research Report - University of Florida Agricultural Research Center ; 1983-8 ( English )
Physical Description: Serial
Language: English
Creator: Mislevy, P.
Kalmbacher, R. S.
Everett, P. H.
Horner, E. S.
Publisher: University of Florida Agricultural Research Center
Publication Date: 1983
 Record Information
Bibliographic ID: UF00075790
Volume ID: VID00007
Source Institution: University of Florida
Rights Management: All rights reserved by the source institution and holding location.
Resource Identifier: oclc - 143646330

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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 1983

Research Report RC-1983-8



COMMERCIAL CORN VARIETY TEST RESULTS

FROM SOUTH-CENTRAL FLORIDA, 1983

P. Mislevy, R. S. Kalmbacher, P. H. Everett and E. S. Homer



Corn can be extremely valuable in a livestock feeding program. With

its rapid growth and high yielding ability, corn harvested kA4e&reL RARY

silage can supplement perennial grasses at times when the r pro4dtijkd (65

low. Corn may follow winter vegetables or be used in a p .St .rey. tioForida

program. High quality corn silage can provide dairy and beef cattle with a

substantial carbohydrate input, possibly reducing high grain costs and

providing growing calves with quality feed.

Well managed corn harvested for silage at the proper state of maturity

can produce 7 to 12 t/acre of dry matter in a 3.5 to 4.0 months. 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, 8% crude protein and 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, and weed, insect and disease control are

necessary.



1/ Professor and Associate Professor, respectively, Agricultural Research

Center, Ona; Professor, Agricultural Research Center, Immokalee;

Professor, Agronomy Department, Gainesville, Florida.










The purpose of these studies was to evaluate commercial corn hybrids

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

a randomized complete block with 4 replications. Twenty seven commercial

corn varieties were seeded at Ona and twenty at Immokalee. The experiment

at Ona was seeded on Ona fine sand on April 4 and reseeded April 19, 1983.

The Immokalee experiment was seeded on Immokalee fine sand on February 8

and reseeded on February 25 and again on April 4.

Fertility

Fertilization practices at Ona were 980 lb/A of 0-10-20 (N-P205-K20) +

20 lb/A FTE 503 micronutrients prior to seeding. One ton/A of dolomite was

applied to maintain pH and supply Ca and Mg. Nitrogen was applied at a

rate of 130 Ib/A pre-emergence, and 80 Ib/A when corn plants were 24 inches

tall.

At Immokalee 50-50-100 lb/A of N-P205-K20 with 20 lb/A FTE 503 was

applied and disked into the seed bed prior to seeding on February 8. No

fertilizer was applied before reseeding on February 25, but 50-45-90 lb/A

of N-P205-K20 was again applied when the experiment was reseeded for the

third time on April 4. On April 29, when corn was 10 inches tall,

120-50-50 lb/A was applied, and on May 17, when corn was 22 inches tall,

100-50-50 was applied. Micronutrients were applied on May 11 as a foliar

spray to help correct yellowing.

Plant populations and pest control

Corn at Ona was seeded in 30 inch rows and adjusted to a final

population of 26,000 plants per acre. In Immokalee the corn was seeded in






3



30 inch rows and adjusted to 25,000 plants per acre. Herbicide practices

used at Ona were 2.0 lb/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 Dasanit(R) 15 G (2.0

lb active/A) was applied in a 7 inch band at seeding, to control soil

insects. The insecticide Mesurol(R) was applied on the seed at the rate of

1 lb commercial product/100 lb seed to repell birds.

At Immokalee AAtrex(R) was applied at 2.0 lb active/A in combination
(R)
with Lasso(R) at 2.0 lb active/A at the first seeding. Lasso was reapplied

at 2.0 lb/A at the April 4 reseeding. Furadan 10 G was applied at 10 lb/A

(active) in the row at each seeding. Mesurol(R) was applied at the same

rate used at Ona. Corn was sprayed with Lannate 1.8L(R) on April 15 and 21

and May 10 at 2 pints/100 gal. of water to control bud worms.
Irrigation

A total of 2.6 inches of 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.

Corn maturity at harvest

Corn was harvested when the kernels were at the hard dent stage as

recommended for silage production. This was coincidental with black layer

formation at the base of kernel in most varieties. The experiments were

also harvested for grain. All values were converted and expressed in

bushels 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 1983 growing season were very good averaging 8.0 t/A (Table 1).










These yields ranged from a high of 10.6 t/A for Northrup King 'PX 9692' to

a low of 6.3 t/A for 'Coker C 19'. The 1983 corn experiment was delayed in

seeding by about 45 to 50 days due to excessive soil moisture.

Consequently, the corn was not seeded until April 19 and harvested July 27,

1983. As a result, corn was mature (average 50.0% forage dry matter) and

ready for harvest in only 99 days due to the high temperatures of May, June

and July. Corn matured about 20 to 25 days earlier than plants seeded at

the normal February 20 to March 10. Dry matter ranged from a high of 59.3%

for Paymaster UC-7251' to a low of 43.5% for Dekalb 'XL 395 A'. The

ability of top yielding hybrids to dry rapidly is a very desirable

characteristic. Fast drying indicates that a variety would be ready for

ensiling (30 to 40% dry matter) sooner, allowing the producer to remove the

crop before the start of summer rains. Varieties like Ring Around 'RA

1604' and 'Pioneer 7360' have this characteristic.

Growers should also consider using early maturing hybrids like Asgrow

'RX 114' and 'Big D 6986', which mature 7 to 14 days earlier than full

season hybrids, allowing growers to harvest sooner. This allows the grower

additional time for seeding the second crop before summer rains. Early

maturing hybrids generally produce low dry matter yields (Table 1), but

plants dry fast, have low kernel moisture, and have good grain yields and

grain to stalk ratios.

Grain yield is another characteristic to consider when selecting

corn hybrids. Grain yields in 1982 averaged 139.3 bu/A shelled corn

adjusted to 15.5% moisture. Even though the 1983 crop was mature in 99

days, forage (-1.3 t/A) and grain yield (-47.6 bu/A) was reduced

considerably compared with the 1982 crop, which required an average of 118

days to maturity. The highest grain yielding variety in 1983 was Big D






5



'6986' producing 180.7 bu/A shelled corn. This variety dried relatively

fast averaging 29.2% kernel moisture and 50.5% plant dry matter at harvest.

When selecting corn hybrids for silage an important factor to consider

is the grain to stover ratio. The grain to stover ratio is expressed as a

percentage by weight of grain available in the silage. Corn varieties with

a relatively high forage dry matter yield and low grain yield (Dekalb 'XL

82' or Northrup King 'PX 9692') resulted in a low grain-stover ratio (35-65

or 36-64%) (Table 1). There are other varieties (Funks 'G 4733') that

produced high grain yields and low forage yields (short stalks) resulting

in a 54-46 grain-stalk ratio. When selecting a corn hybrid, choose a

variety with a high dry matter yield, high grain yield and high grain to

stover ratio. Varieties like Pioneer 7360 and Jacques JX 247 are two

varieties that fit these criteria.

Southern corn rust (Puccinia polysora) was not a serious problem

during the 1983 growing season. However, due to the late seeding (April

19) army worm (Spodoptera frugiperda Smith), commonly called bud worm,

damage was greater than normal, especially when plants were greater than 3

ft tall.

ImmokaZee ARC

Excessive rain and saturated soil resulted in a loss of the first two

seedings made on February 8 and 25. The April 4 planting was successful,

but was about 60 days later than the normal early February planting. Even

with a rim-ditch and lift pump excessive water can still be a major

limiting factor for south Florida corn production. It is unusual for

rainfall to be excessive in late winter, and this was the first time in 8

years of testing corn at Immokalee that the problem occurred.

There were no significant (P<0.05) differences in the dry matter










yields of the twenty varieties tested (Table 2). Yield ranged from 3.6 to

6.9 t/A and averaged 5.5 t/A. Inspite of a relatively large difference in

the range, variability was too great for detection of significant

differences.

Varieties producing significantly higher yields in past years were

again superior in 1983 (Ona Research Report RC-1981-10 and RC-1982-6).

Northrup King 508, Dekalb XL 395 A were better yielding full season

hybrids. Inspite of the advantages of early harvest date and high corn

grain to stover ratios, the short season hybrids have yielded well at

Immokalee. Based on test results of 3 to 5 years the full season hybrids

(NK 488, Dekalb 1295, NK 508, Dekalb XL 395 A and Coker 77) have been

better yielding hybrids, especially when compared with the short season

varieties (Table 3).

Fertilization of the trial was designed to produce high yields, but

fertility was still a limiting factor because nutrients were not getting to

the plant when needed. After March, rain ceased and during April and May

there was a protracted dry period. Top-dress applications of N, P, and K

applied to a crop with seepage irrigation do not get into the roots unless

rain or overhead irrigation occur, or unless fertilizer is cut into the

soil. Corn remained in a stunted condition until rain occurred in late May

and moved nutrients into the root zone. The growth that followed these

rains was not enough to compensate for limited earlier growth.

Plant dry matter averaged 38.6% and ranged from 31.6% to 46.7%, and

significant (P<0.05) differences in dry matter were found (Table 2).

Once plants reach physiological maturity, drying occurs very rapidly in hot

summer.










There were significant (P<0.05) differences in yield of grain which

averaged 98 bu/A (Table 2). Grain yield was considerably lower than in

other years (Ona Research Report 1981-10, RC-1982-6). Better grain

producers were Dekalb XL 395 A, McCurdy 80-72, Coker 21, Northrup King NK

508, which also yielded more total forage. McCurdy 67-14, Ring Around RA

1604, and Dekalb XL 395 A have been better yielding grain varieties in past

years (Table 3).

Kernel moisture averaged 33.8% and ranged from 28.3% (Pioneer 3165) to

38.9% (Jacques 247)(Table 2). Significant differences in kernel moisture

were found among varieties. Shelling percentage (amount of grain on the

ear) averaged 81.7%. This value ranged from 72.6% (Coker 16) to 88.0%

(Pioneer 8100).

The grain to stover ratio averaged 46-54 and ranged from 32-68 (Coker

16) to 60-40 (Golden harvest H 2680). Harvest index (grain yield total

crop yield) was 0.46 in 1983, which was lower than that observed in other

years. Average harvest index at Ona and Immokalee during the past 5 years

has been 0.51 and 0.50, respectively. The lower index is probably a

reflection of the late planting date.

Variety selection at Ona and Imnokalee

When considering commercial corn hybrids for forage and/or grain

production in the Ona area it is desirable to select varieties that have

performed consistently well over a three to five year period. Based on

these data Northrup King NK 508, Coker 77 and Ring Around RA 1604

consistently produced 10+ t/A dry matter. However, if grain production was

the objective, Ring Around RA 1604, Jacques JX 247 and McCurdy 67-14

yielded 179, 183 and 183 bu/A, respectively. In the Immokalee area






8



Northrup King NK 488, NK 508, Dekalb 1295 and XL 395 A and Coker 77 are the

recommended varieties for both forage and/or grain.

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, resulting in a high (50-50 or above)

grain to stover ratio. Varieties selected should also have a high forage

dry matter percentage and low kernel moisture. If corn hybrids are grown

for grain, then high grain yields at low kernel moisture should be

selected. Kernel moisture is extremely important since it is an indication

of how fast a hybrid dries, allowing for an earlier harvest. In 1983

Pioneer 7360 and Ring Around RA 1604 were two varieties that met these

criteria at Ona. Superior varieties at Immokalee were Northrup King NK

508, Coker 21, McCurdy 80-72 and Dekalb XL 395 A.









Tabi


Forage and


grain


yields


other


agronomic


variables


of commercial


corn


varieties


the Ona


ARC,


1983


Forage


Brand


Variety


Yield


dry matter
At harvest


Grain t


yield


Kernel


sture


Shelling


percentage


bu/A


Northrup


King


Ring Around
Pioneer


Dekalb
Dekalb


Jacques
Jacques
Golden Harvest


Ring Around


Jacques
Northrup
Pioneer


Coker


McCurdy
Paymaster
Funks
McCurdy
Paymaster


King


PX 9692
RA 1604
7360
XL 82
XL 395
JX 247


3126


10.6


32.9


a-c


a-c


52.0


115.5


c-e


33.0 b


38.3


92.9


51.3


30.8


H 2680
RA 1502
JX 8400


PX-79


3187
C 21


80-72


UC-8951
G 4522


53.4


51.2


.0 b-d
.0 b-d
.0 b-d


50.9


.0 d-i


28.8


86.3


87.8
85.2
80.5


31.4


84.9


135.8


8150


UC-7251


122.2


31.0
30.5


c-e


6986


Asgrow
Coker
Asgrow
Pioneer


Funks


Jacques
Northrup
Coker


King


180.


RX 114


53.1


RX 909


129.


29.2
25.2
27.4
30.5


3165


G 4733
JX 8100
PX 9581


.8 cd


119.3


86.1


85.0
88.3
81.2
85.8


c-e


30.2


C 19


Avg.


30.3










Table


Forage and grain


yields


other


agronomic


variables


of commercial


corn


varieties


the Ona ARC,


1983,


cont.


Means within


a column


followed


same


letters


are


significantly


different


(P<0


Duncan


Multiple


Range


Test.


Based


on 15


moisture


(shelled


corn)


Determined


at harvest.


Calculated


on oven


basi


Seeding


date


7-83,


reseeded


4-19-83


due to saturated


soil.


Plant


population


(final)


26,000 plants/A.


Insecticide


Dasanit (R)


Ib/A


commercial


product


in 7


inch


corn


row,


at seeding.


spacing


30 inches


Fertilization


0-100-20
Applied


0 Ib/A N-P 05-K20, respe
130 Ib/A N pre-emergence


actively +


corn,


20 Ib/A FTE
80 Ib/A N w


503 and


hen


corn


plants


dolomite


were


Herbicide


Pre-emergence


application


of AAtrex(R)


Lasso(R)


at 2


.0 ib/A


(active),


respect


Irrigation


Applied


inches


of water via


overhead


sprinklers.


.(


.










Table


Forage


grain


yields


other


agronomic


variables


of commercial


corn


varieti4


Immokalee


ARC,


1983


Brand


Variety


Forage
Yield


dry matter


At harvest


Grain
yield


Kernel


sture


Shelling


percentage


bu/A


Northrup
Coker
McCurdy
Dekalb
Pioneer
Asgrow
Jacques
Northrup


King


C 21


.4 a


38.9


XL 395


King


Paymaster


Ring


Around


McCurdy
Northrup
Jacques


Golden
Coker


King


Harvest


Funks
Paymaster
Coker


Pioneer
Jacques


3187
RX 9399
8400"


PV 71o


SI
UC 8951#


.8 a


RA 1#04
8150" #
PX 9581"
JX 247f
H 26O0"
C 16
G 4740
UC 7251"
C 19-
3165
JX 8100#


Avg.


125.5
130.6


a-c


a-e


36.7


83.5


a-c


.0 cd


83.3


33.5
29.6


76.1
93.8


37.8
35.7


36.7


32.5
31.6


92.4
110.5
120.3
103.4


a-e


a-e


32.8
37.7


a-e


32.4
33.4


38.9


120.


75.8


.8 a-f
.0 d-f


30.0
35.8
29.5


c-e
a-c


61.7


33.8


a-e


84.6
75.9
80.8
80.8
80.0
86.3


a-c


82.0 a-d
79.0 cd


82.8
81.7


83.2
81.8
88.0
80.2
81.7


a-c


a-c









Table


Forage


grain


yields


other


agronomic


variables


of commercial


corn


varieties


Immokalee


ARC,


1983,


cont.


* Means within


a column


followed


same


letters


are


significantly


different


(P<0.


Duncan's Multiple


Range


Test.


Based


on 15


moisture


(shelled corn)


Determined


at harvest.


Calculated


on oven


basis.


Earlier varieties


harvested


13 July


later varieties,


20 July


(100


107 day


growing


Seeding


date:


February


reseeded


on February


25 and April


because


excess


ive rain.


Plant


population


25,000


plant


s/acre


Insecticide:


Furadan


10 G


at 2


lb/A


(active)


spacing


30 inches


Fertilization


On February
Ib/A of N-P
N-P205-K 0.
N-2 5 2


50-50-100


05-K20.


Ib/A of


On April


N-P 0O-KO di
120-50-56 lb/


sked


A and


into


seed


on May


On April


100-50


-50 lb,


Herbicide:


On February
lb/A.


Lasso(R)


and AAtrex(R)


at 2


lb/A,


respectively


On April


Lasu


Irrigation


Seepage


with


lateral


on 40'


centers.


0


SE










Table 3. Average grain and forage dry matter yields of selected varieties
grown at Ona and Immokalee over the past five years, 1979-83.


Grain @ Forage
Brand Variety 15.5% moisture dry matter

bu/A t/A


Ona


Northrup King
Coker
Ring Around
Dekalb
Jacques
Funks
McCurdy
McCurdy
Asgrow
Funks
Funks
Asgrow


Northrup King
Dekalb
Northrup King
Dekalb
Coker
McCurdy
McCurdy
Asgrow
Ring Around
Funks
Asgrow
Coker
Jacques
McCurdy
Pioneer
Funks
Funks


NK 508
77
RA 1604
XL 395 A
JX 247
G 4864
67-14
8150
RX 114
G 4507
G 4740
RX 909
Average


171
154
179
152
183 t
159
183
163
156
146
164
161
164



134
139
127
144
127
150
132
129
140
140
128
140
136
131 t
115 t
108 1
118
131


NK 488
1295
NK 508
XL 395 A
77
67-14
84AA
RX 909
RA 1604
G 4864
RX 114
22
JX 247
8150
3320
G 4740
G 4507
Average


10.9
10.5
10.2
9.6
9.6
9.4
9.3
8.5
8.4
8.4
8.1
8.0
9.2


Immokalee


8.6
8.2
8.0
7.8
7.8
7.7
7.3
6.9
6.8
6.7
6.5
6.3
6.3
6.3
6.3
5.9
5.4
7.0


Based on 3 years data

+ Based on 4 years data

Based on 5 years data




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