/o6

STUDIES WITH POPCORN VARIETIES IN THE EVERGLADES AREA
1952-1957
by
Victor E. Green, Jr. and Enmett D, Harris, Jr,

This report contains results of research with popcorn
grown on organic soils in South Florida and supercedee
Mimeo 57-4. The work was conducted in cooperation with
the Central Popcorn Company of Schaller, Iowa, who fur-
nished seed and determined expansion ratios.

EVERGLADES STATION MIMEO REPORT 58-4
Belle Glade, Florida

October 3, 1957

)e#3HHHt#~H(~Ht~Ht3n?~~SHe~#SHYUUUUWUD

6-11

STUDIES JITH POPCORN VARIETIES IN THE EVERGLADES AREA
1952-1957

by
Victor E. Green, Jr. and Emmett D. Harris, Jr#-

To date, the agronomic research on popcorn in the Everglades area has con-
sisted chiefly of screening released and experimental hybrids. Tests were begun in
1952 and are continuing. Poor yielding and disease susceptible varieties are dis-
carded each year and are replaced by other varieties.

The tests have had the following characteristics in the various years:

1992 19~3

Number of Varieties
Date of Planting
Dates of Harvest

6
3-6-52
6-16-52
to
7-3-52

4
1-28-53
5-28-53

19)i1

12
2-1-54
5-21-54
to
6-9-54

19~

15
1-28-55
66--55
to
6-20-55

19;6

19
1-30-56
6-7-56

19~7

21
2-7-57
6-5-57
aad
6-18-57

Width between rows, feet
Drill Spacing-Plants/Hill
Population, Plants/Acre
Row Length, Feet
Rows per Plot
Harvested Area, Rows
Replications, Number
Design, Randomized Com-
plete Block
Insect Control
Leaf Blight Control

Three-foot rows used
2-15" 1-12" 1-12"
19,333 14,520 14,520
50 50 50
3 6 3
1 6 3
4 4 3
R.C.B. Latin R.C.B.
Square
3 sprayings/crop of 1 quart
None in any year

each year
1-12" 1-12" 1-12"
11,520 14,$20 14,$520
0o 89 25
3 1 1
1 1 1
4 4 4
R.C.B. R.C.B. R.C.B.

25% DDT emulsion per acre

Each year wireworms were controlled by applying 3 to 5 pounds of technical aldrin
per acre into the soil by spraying and immediately disking. Annually, the crop was
planted and thinned by hand, and skips in the stand were replanted soon to insure
a perfect stand. Cultivations numbered three per crop at about two-week intervals
after germination. Soil was thrown to the rows to help reduce root lodging.

Stalk and ear heights were measured following anthesis. About two weeks
after anthesis, reaction to northern leaf blight caused by Helminthosporium turci-
cum Pass. was determined. No blight readings were made in 19-5. -'193, 5thy
were made by W, N. Stoner, then Assistant Plant Pathologist, Everglades Station:
in 1954 by the Senior Author, and in 1955 to 1957 by Miss Alice Robert of the Crops
Research Division, U.S.D.A.

As the varieties ripened, they were picked, husked and weighed. Samples
were taken for moisture determination, weight-per-bushel test, and for popping.
The latter two tests were performed by the Central Popcorn Company. Yields were
calculated at 15.5 percent moisture on an acre basis. Shelling percentages were
calculated in 1955 and 1956.

I/ Victor E.
Entomologist,

Green, Jr., Associate Agronomist and Emmett D. Harris, Jr., Assistant
Everglades Experiment Station, Belle Glade, Florida.

. "- -=-- "_--q "-- -- --19 7

-2-

The test in 1952 was merely observational and was carried out to check
whether any of the varieties from Iowa were adaptable to the south Florida environ-
ment, The March 6 planting yielded marketable popcorn, but the April 1 planting
was a complete failure. All corn usually fails when planted late in this area.
Table 1 shows the 1952 yields and harvest dates.

Table 1. The Characteristics and Performance of Six Popcorn
Varieties at Belle Glade, Florida, 1952.

Central Hybrid
Number

Yield, Ibs./A
at l; 1 g Moiln't~e

Date of Harvest I/

1 1930 7-2-52
2 1745 7-2-52
3 2065 7-3-52
4 1860 7-3-52
5 585 6-16-52
6 325 7-3-52

/ Planted March 6, 1952

In 1953, four improved varieties were received from the Central Popcorn
Company. They were numbered according to days required to approximate maturity
near Schaller, Iowa. The data collected during 1953 are shown in Table 2.

Table 2. The Characteristics and Performance of Four Popcorn
Varieties at Belle Glade, Florida, 1953

Variety Yields, Ibs/A
at 15.5%
Moisture

Disease
Index /

Stalk
Ht., Ft,

Popping
Expansion,
Volumes

Normal
Expansions,
VonlumAM

Moisture
at Harvest,2/
$

C-105 1985 0.5 6 27 32 21.97
C-110 2600 2.0 8 29 33 18.82
C-112 2780 4.0 8 33 35 241.46
C-115 3330 3.0 8 35 35 26.06

L.S.D. for yields: ,05 506 Ibs.) .01 = 766 Ibs.
R/ eadings on April 23. Higher numbers indicate more
/ Planted January 28, 1953. Harvested May 28, 1953.

injury. Scale 0-5

The variety C-115, the latest maturing variety, yielded better than the
earlier varieties, even though resistance to Helminthosporium leaf blight was great-
er in two of the other three. On lots of seed that were dried, shelled and equal-
ized for prime moisture content, the popping volumes of Florida grown material were
two to four volumes lower than Iowa grown corn. This was the first indication that
the later varieties might give the highest yields and the best popping quality in
south Florida. The shortness of the stalks suggested the possibility of combining
the grain,

Hybrid 110 had considerable weevil infestation, but the other hybrids
were free from insect damage. The ears of 115 were normal in size, while those
of the earlier varieties were much shorter than normal,

-3-

During the crop year 195~, the five best 1952 varieties, the 1953 varie-
ties, Purdue 31 and 32, and Japanese Hulless (Improved Baby Rice) were grown. 1954
was a bad blight year and some of the varieties had dry leaves when the grain was
in the milk stage. Stalk heights did not exceed seven feet and ears were no more
than three and one half feet from the soil surface. With such low ear formation,
weed control assumes major importance. Expansion of the kernels was reduced by 2.5
to 8 volumes by leaf blight. The variety Central Hybrid 1 was the highest yielding
variety, 2990 pounds per acre. Central h rated second. Both these varieties had
the highest popping volumes. See Table 3.

In 1955, Central Hybrids 1, 2 and 4 were planted again along with ten new
releases from Iowa, the variety South American and the inbred YS(RS)F11 from the
Cuba Agricultural Experiment Station. The year was very good from the standpoint
of corn production. Blight readings were not taken until three weeks before harvest.
Good yields were received from all varieties except South American, Stalk heights
of the corn belt popcorns varied from 54r feet to 6,8 feet and all varieties seemed
well suited to combine harvesting if care is taken not to break the hull of the
grains. The Cuban variety averaged 8.8 feet in height and possessed the most resis-
tance to 3e af blight. It yielded 3670 pounds per acre. However, it had the lowest
shelling percentage and popping volume. It required three additional weeks to ma-
turity when comparedo with the other varieties. The data collected in 1955 are shown
in Table 4U In 1955, the popping volumes of Florida grown corn were higher than the
normal expansion figures for all varieties. Shelling percentages of the Central
varieties were between 76.7 and 82.5, and the Cuban variety, due to a large cob,
yielded about 72 percent grain. Central Hybrid 4 was the earliest maturing variety
as reflected by the moisture content at harvest.

In 1956, 19 varieties of popcorn were grown. These included the best
varieties from former years along with additional crosses from the Central Popcorn
Company. Central Hybrid No. 1 gave the highest yield of grain again for the third
year. The characteristics and performance of the varieties are shown in Table 5.

In 1957, northern leaf blight assumed epiphytotic proportions. This fac-
tor along with an extremely high rainfall during the early growth of the plants
caused severe stunting and reduced yields. The three highest yielding entries were
experimental varieties 7-303, 7-336 and 7-310 from the Central Popcorn Company.
However, the varieties scoring less than 3.0 for blight were Purdue 202 and Central
Hybrid No. 1. The tallest stalks did not produce the highest yields. Nor were high
yields related to the length of the growing season. The agronomic and industrial
characteristics of the popcorns grown in 1957 are shown in Table 6.

On June 21 and 22, 1956 a 25-ear sample was taken from each replicate of
each variety and examined for tip and side injury by the corn earworm, Heliothis
zea (Boddie) and also for weevil injury. Injury to the side of the ears bF the corn
earworm and injury by weevils was too light to make comparisons and the data are not
given in this paper,

For tip injury by earworms, each ear was given a score (0 to 5) based on
the depth from the tip that feeding occurred. The number of ears of each sample
having a certain score were multiplied by that score and the resulting products were
added and the sum divided by 25 and multiplied by 100. The average score for four

Table 3.--The Characteristics and Performance of 12 Popcorn Varieties at Belle Glade, Florida, 1954

Variety 1/

0'1
C-4
c-;
P-32
C-2
C-3
C-115
0-105
P-31
C-$
C-110
Jap. H.
C-112

Yields, Ibs./A
at 15.5% Moisture

2990
2270
2200
2080
2020
1980
1670
1600
1480
1380
980
950

Date
of
Harvest

6- 8-54
5-25-54
6- 9-54
6- 8-54
6- 8-54
6- 9-54
5-21-54
6- 8-54
5-25-54
5-25-54
5-21-54
6- 2-54

Disease
Index 2/

2.0
2.5
2.0
3.0
2.5
2.5
3.0
2.0
3.0
4.0
2.5
4.0

Height, Ft.
Stalk Ear

6.0
5,5
7.0
6.5
6.5
7.0
6.0
7.0
6.0
7.0
6.0
6.5

3.0
2.5
3.5
3.5
3.5
3.5
2.5
3.0
2.5
3.0
2.5
3.0

'eight/
bushel,
lbs.

65.5
63.0
65.0
65.5
62.0
64.0
61.0
63.5
61.5
61.0
59.5
63.0

Popping
Expansion,
Volumes

Normal
Expansion,
Volumes

32.5
33.5
31.5
31,0
31.0
26.0
29.0
26.0
30.0
30.0
30.0
21.5
30.5

L.S.D.. for yields: .05 750 Ibs; .01 = 1000 Ibs.

Y C = Central Popcorn hybrid; P Purdue Hybrid

2/ Readings on April 26. Higher numbers indicate more injury

Table h. The Characteristics and Performance of 15 Popcorn Varieties at Belle G2ade, Florida. 1955,

Variety 2/

fields, Ibs./A.
at 15.5% Moisture

Disease
Indez y/

Weight/
Bushel
Ibs.

Popping
I:pansion,
Volumes

Normal
Expansion,
Volumes

Moisture
at
Harvest. f

Shelling
Percentage

C-1 By.
C-06-319
C-5423
Y S(as) F11
C--5428

C-4 By.
C-54A0!
C-5-409
C-2 Hr
0C--136
C-$5-331
C-5-330
C-5-332
South American

L.S.D. for Yields, 0.5 =

1280 Ibs.* .01 1710 Ibs.

C Central Popcorn Comparr; IS(RS) F11 is an open-pollinated variety from the Cuba Agri.
Readings on May 16. Higher numbers indicate more injury.

Expt. Station.

Planted Jan. 28, 1955. Harvested June 6, 1955.
June 20.

High moisture indicates lateness.

YS(RS) F11 harvested

4610
4260
3670
3670
3130
3110
2P90
2990
2920
2750
260
2640
2370
2330
1060

3.1
4.0
4.0
3.0
3.6
4.5
4.5
6.1
3.8
3,6
4.5
4.8
5.0
4.9
4.9

6.8
6.3
6.0
8.8
5.8
6.0
5.14
6.0
6.0
7.0
5.9
5.9
6.0
5.8
6.3

3.6
3.3
3.0
5.1
2.9
3.0
2.8
2.8
2.9
3.6
3.0
3.0
2.8
3.0
3.3

65.5
66.5
63.5
65.0
65.5
66.5
65.0
65.5
63.0
65.5
66.0
63.5
63.5
62.0

37.5
40.0
38.0
23.0
38.0
39.0
39.0
40o0
39.0
36.0
37.5
40.0
37.5
40.0
31.5

31.14
28.59
23.57
34.40
24.17
28.59
21.20
25.77
29.61
32.77
23.72
23.57
24.33
28.59
23.72

82.5
77.6
79.9
71.9
78.4
78.2
76.7
78.3
79.8
80.6
81.3
80.4
79.6
81.3
78.7

_ __

_

Oight, Ft.
Staln Ear

Table 5. The Characteristics and Performance of 19 Popcorn Varieties at Belle Glade, Florida. 1956

Height, Ft. Wt/Bu. Popping
Stalk Ear Lbs. Expansion,
Volumes

Normal
Expansion,
Volumes

Shelling
Percent-
age

Years
Grown
Yrs.

Yield, Av.
Ibs./A Q
15.5

C-I-HY
C-6-329
P-31
C-5-401
P-32
C-2-HY
c-55
C-6-343
-11n5
C-S-HY
P-202
C-6-&117
C-4-HY
C-6-303C
YS(RS)FU1
C-6-412
C-6-337
C-6-312
C-105

3085
2750
2560
2550
2515
2500
2435
2370
2370
2345
2335
2325
2255

2125
2065
1720
1450
1365

1.9
2.1
2.1
2.6
2.3
2.5
2.3
2.7
2.1
3.1
1.4
2.5
3.0
2.1
1.9
2.8
2.3
1.6
3.3

6.0
6.3
6.5
5.9
6.5
6.5
5.6
6.8
6.5
6.0
5.1
5.9
5.3
6.0
6.4
5.6
6.1
6.1
5.5

3.3
3.1
3.0
2.9
2.6
3.3
2.8
3.6
3.5
2.4
2.9
3.1
2.8
2.8
3.5
2.6
3.0
2.9
2.4

65.7
67.0
66.0
67.0
66.0
66.7
65.0
66.0
66.3
65.3
66.0
66.0
65.3
66.0
61.5
65.0
66.3
65.6
62,7

36.0
35.0
34.0
37.0
36.0
32.0

36.5
33.0
40.0
38.0
38,0
38.0
35.0
33.0
37.5
37.5
33.0
34.5

84,1
81.8
82.4
80.6
82.8
80.3
81.5
82.3
83.3
82.3
78.5
80.9
79.2
82.1
76.7
85.1
83.6
77.9
76.8

4 3155
2 2080

2360
2270

2560
1470

4 2345
2 2900

3 1675

No Significant

Difference between Yields

V C Central Popcorn Company. YS(RS)F11 is an open-pollinated variety from the Cuba Agr. Exp. Sta.
2/ Readings by Miss Alice L. Robert, FCRB, ARS, USDA on May 15, 1956. Scale 0-5. 0 No injury.

P = Purdue Hybrid

Planted January 30, 1956 Harvested June 7, 1956

Variety~/

Yields
Ibs./A 0
15.5 %

Disease
Index
2/

Table 6. The Characteristics and Performance of 21 Popcorn Varieties at Belle Glade, Florida. 1957

Height,Ft.
Stalk Ear

Wt./Bu.
Lbs.

Popping
Expansion,
Volumes

l4ormal
Expansion,
Volumes

C-7-303
C-7-336
C-7-310
C-7-389
C-1-HY
P-31
C-7-419
C-4-HY
P-32
C-7-374
0-7-369
YS(RS)F11
C-6-408
C-7-313
Gattoni
C-7-300
C-15
C-7-432
C-7-424
P-202
C-7-306

3120
2735
2555
2080
1950
1950
1730
1615
1540
01465
1405
1395
1385
1380
1280
1250
1200
1075
10O0
985
850

3.5
3.0
3.8
3.8
2.9
3.3
3.9
4.0
3.1
3.0
3.8
3.3
4.4
3.3
3.0
4.3
3.3
3.6
3.0
2.5
3.3

5.5
6.5
5.5
6.0
5.0
5.5
5.0
4.5
5.5
6.5
5.5
5.0
5.0
6.0
8.0
4.5
5.0
5.5
5.0
4.0
5.5

3.0
3.5
2.5
3.0
3.0
2.5
2.5
2.0
2.5
3.0
3.0
2.0
2.0
3.0
4.5
2.0
2.5
3.0
2.5
2.0
3.0

30.0
35.0
29.0
31.5
34.0
24.0
32.0
31.5
24.0
28.5
30.5
33.0
30.5
35.0
10.0
31.0
29.0
30.5
29.0
27.0
33.0

84.1
82.4

82.8

76.7

83.3

78.5

18,98
26.00
17.34
20.00
18.37
19.34
19.34
17.84
20.00
22.67
16.33
17.58
17.94
22.67
16.84
16.62
29.00
22.67
18.64
15.55
18.64

2915
2035
2200
2085

3 2395

4 2220

2 1660

LSD .05 -

SC = Central
Cuba,

665 Ibs;

LSD .01 885 lbs.

Popcorn Company; P = Purdue Hybrid. Gattoni is an open-pollinated variety from Panama and YS(RS)F11 is from

2/ Yields joined by the same vertical line are not significantly different from each other, whereas those not joined are.

3~ Readings by Miss Alice L. Robert, CRD-ARS-USDA. Scale 0-5. 0 No injury. May 8, 1957.
Planted February 7, 1957 Harvested June 5, 1957. Gattoni Harvested June 18, 1957.

Variety
1V

Yields,
Lbs ./A@
1S.6'W

Disease
Index
I1

Shelling
Percent-
age, %

Moisture
at
Harvest
%

Years
Grown,
Yrs.

Av.Yield,
Lbs./A 0
15.5%

___

-4-

replicates of each variety is reported along with the percentage of worm-free ears
(Table 7). The method of scoring was as follows:

Score Amount of Injury

None
Up to 1/8
Up to 1/4
Up to 1/3
Up to 1/2
More than

the
the
the
the
1/2

length of the
length of the
length of the
length of the
the length of

Of the 25 ears in the sample, five ears of representative size were mea-
sured to obtain an average for each replicate of each variety. The number of ears
per plot had been counted when the popcorn was harvested (Table 6).

The data were analyzed statistically in such a way that the effect of
ear length, number of ears per plot, and yield upon the earworm score could be
determined. The length of ear did not have a significant effect upon the earworm
score (r 0.2220). As the weight (r -0.4203**) and the number (r -0.2784 *)
of ears per plot increased the amount of injury as measured by earworm score
decreased.

Variety C-6-329 had significantly less earworm injury than all other
varieties except P-32, C-I-4Y, C-6-312, C-55, and C-6-417 in 1956.

In 1957, because of low yields, it was necessary to omit some of the
varieties from the entomological investigation and to examine only 10 ears per plot.
For damage by both corn earworm, Heliothis sea Boddie and scored-grain insects
(predominantly the rice weevil, Spitohilus orya (L.) each ear was scored from 0 to
5 to indicate the degree of injury. The scores were averaged and multiplied by 100
for each plot. These examinations were made July 31, 1957, or 56 days after harvest.
Between the time of harvest and examination the ears were stored in open bags with
no protection against stored grain insects. The method of scoring was as follows

Corn Earwonm

no damage
damage to tip of ear only
damage to kernels to one-half
inch below tip of ear
damage to kernels to one
and one-fourth inches below tip
damage to kernels to two
and one-half inches
below tip
damage to kernels to more than
two and one-half inches below
tip

Stored Grain Insects

no damage
1-10 kernels
10-20 kernels

20-30 kernels

30-40 kernels

50 plus kernels

Differences among varieties in the degree of earworm damage were non-
significant (table 8). Among the varieties examined, C-7-336 was significantly more
resistant than all varieties other than C-7-310 and C-6-408 to stored-grain insects.
In 1957, the number of ears yielded per plot did not have a significant effect on
the degree of earworm or stored-grain insect damage.

ear
ear
ear
ear
the ear.

No.
I -

Table 7. Earworm Damage, Number, and Length
Belle Glade, Florida. 1956

of Popcorn Ears

Variety

c-6-329
P-32
C-1-NH
C-6-312
c-55
c.6-117
P-31
C-2-HY
c---o01
YS (RS)FU
C-6-)l12
P-202
c-6-337
c-4-HrY
C-6-303C
C-115
0-6-313
C-s-HY
0-10$

Length of
Ear, nmm

18.:4
16.1
14.7
16.2
17.3
16.0
17.1
16.6
16.5
18.0
16.6
16.0
16.3
16.0
15.8
15,3
17.0
17.1
16.6
11.2

Av. Number of
Ears/Plot

105
121
139
83
110
111
116
115
117
102
102
97
85
12)4
109
104
125
125
102

a Scores joined by the same line are not significantly different from each other
Scores not joined by the same line are significantly different from each other.

Table 8. Earworm and'Stored Grain Insect Damage
Belle Glade, Florida. 1957.

Variety

Earworm
Damage

to Popcorn Ears.

Stored Grain
Insect Damage a

14 0-7-336 163 203o
12 C-7-310 155 2231
8 C-6-o08 190 228
10 C-7-303 193 265
2 C-4-HY 195 277
15 C-7-369 183 290
17 C-7-389 160 298
18 C-7-1l9 200 305
5 P-32 195 313

a Damage scores joined by the same line are not significantly different;
Damage scores not joined by the same line are significantly different.

% Worm-
Free Ears

Earvorm
Score a

110
119i
126
128
130
134
143
1L3
145
165
146
147
147
148
150
157
161
178
282

SUMARY AND CC(CLUSICNS

Tests were begun in 1952 to determine if popcorn could be profitably pro-
duced in the Everglades region of Florida. The area is characterized by high rain-
fall, large corn insect populations and the possibility of an epiphytotic of north-
ern leaf blight annually.

Data collected during the six-year period showed that profitable yields
of high quality grain could be produced by planting early in February, by good in-
sect and weed control measures, and by promptly harvesting the grain as soon as the
moisture therein had dropped to about 25 percent. Sprgring for leaf blight may be
necessary.

Late maturing varieties (requiring in excess of 115 days) gave higher
yields of popcorn with greater expansion ratios. Premature drying caused by north-
ern 3eaf blight was detrimental to expansion of the popped product. The tests show-
ed that in a good year as much as 4600 pounds per acre of popcorn grain could be pro-
duced on Everglades peaty muck soil. The 5 year average for this variety is 2915
pounds per acre.

Tests by the Central Popcorn Company showed that Florida grown grain when
dried properly to prime moisture content would, upon popping, give expansion ratios
up to 0:tl. Normal expansion figures vary 33:1 to 39:1.

Shelling percentages of the varieties varied from 76 to 81 percent grain,
which is quite satisfactory.

Florida-grown popcorn was shown to be excellent for taste, tenderness and
flakiness by numerous testimonials, many of which were voluntary and spontaneous.

* Significant
4. Highly Significant