STUDIES WITH POPCORN


VARIETIES IN THE EVERGLADES AREA
1952-1956


Victor E. Green, Jr. and Emmett D. Harris, Jr.


This report contains results of research with popcorn
grown on organic soils in South Florida. The work was
conducted in cooperation with the Central Popcorn Com-
pany of Schaller, Iowa, who furnished seed and deter-
mined expansion ratios. This paper was read before the
Crops Division of the Association of Southern Agricul-
tural Workers. on February 7, 1956 at Atlanta, Georgia.
The 1956 data were added subsequently,





EVERGLADES STATION MIMEO REPORT 57-4

Belle Glade, Florida


September 17, 1956


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STUDIES WITH POPCORN VARIETIES IN THE EVERGLADES AREA
1952-1956

by

Victor E. Green, Jr. and Emmett D. Harris, Jrd/f


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

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


1952


1953


195


19S5 1956


Number of Varieties
Date of Planting
Dates of Harvest


Width between rows, feet
Drill Spacing-Plants/Hill
Population, Plants/Acre
Row Length, Feet
Rows per Plot
Harvested Area, Rows
Replications, Number
Design, Randomized Complete Block

Insect Control
Leaf Blight Control


6
3-6-52
6-16-52


4
1-28-53
5-28-53


to
7-3-52
3 3
2-15" 1-12"
19,333 14,520
50 $o0
3 6
1 6
4 14
R.C.B. Latin
Square
3 sprayings/crop
None in any year


12
2-l-14
5-21-~1
to
6-9-54
3
1-12"
14,520
50
3
3
3
R.C.B.


15
1.28-55
6-6-55
to
6-20-55
3
1-12"
14 520
to0
3
1
4
R.C.B.


19
1-30-56
6-7-56

3
1-12"
ls,$20
89
1
1

R.C.B.


of 1 quart 25% DDT emulsion


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 1952. In 1953t they
were made by W. N. Stoner, then Assistant Plant Pathologist, Everglades Stations
in 1954 by the Senior Author, and in 1955 and 1956 by Miss Alice Robert of the Field
Crop Research Branch, 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 percept moisture on an acre basis. Shelling percentages were
calculated in 1955 and. 956.


9 Victor E.
tomologist,


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








-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 enviroh-
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, lbs./A
at l5.5% Moisture


Date of Harvest V


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
I/ 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,
Volumes


Moisture
at Harvest,&
g


C-105 1985 0.5 6 27 32 21,97
C-n0 2600 2.0 8 29 33 18.82
C-112 2780 4.0 8 33 35 24.U6
C-125 3330 3.0 8 35 35 26.06


L.,SD. for yields .05 a 506 lbs.; .01 766 Ibse
Readings on April 23. Higher numbers indicate more injury.
Planted January 28, 1953. Harvested May 28, 1953.


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 combing
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 1954, 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 4 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 100 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 5.4 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 leaf 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 compared with the other varieties. The data collected in 1955 are shown
in Table 64

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 is 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.

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
sea (Boddie) and also for weevil injury. Injury to the side of the ears by 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
replicates of each variety is reported along with the percentage of worm-free ears
(Table 6). The method of scoring was as follows:

Score Amount of Injury
0 None
1 Up to 1/8 the length of the ear
2 Up to 3/4 the length of the ear
3 Up to 1/3 the length of the ear
4 Up to 1/2 the length of the ear
5 More than 3/2 the length of the ear.







-4-


Of the 25 ears in the sample, five ears of representative size were meas-
ured to obtain an average length 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
lengthnumber 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 earwormtscore
(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 varie-
ties except P-32, C-1-4Y, C-6-312, C-55, and C-6-417.





SUMMARY AND CONCLUSIONS

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 five-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.

Late maturing varieties (requiring in excess of 115 days) gave higher
yields of popcorn with greater expansion ratios. Premature drying caused by north-
ern leaf 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
produced on Everglades peaty muck soil.

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 40:1. Normal expansion figures vary from 34:1 to 39:1.

Shelling percentages of the varieties varied from 76 to 84 percent grain,
which is quite satisfactory.


* Significant
** Highly Significant










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


Variety /


C-i
C-4
P-32
0-2
0-3
0-115
0-105
P-31
C-5
0-110
Jap. H.
C-112


Yields, lbs./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
5-25-5
5-21-54
6- 2-54


Disease
Index /


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


Weight/
bushel,
Ibs.


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
26.0
29.0
26,0
30.0
30.0
30.0
21,5
30.5


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

SC Central Popcorn Hybrid; P = Purdue Hybrid
2/ Readings on April 26. Higher numbers indicate more injury










Table 4. The Characteristics and Performance of 15 Popcorn Varieties at Belle Glade, Florida. 1955.


Variety 2/


Yields, Ibs./A.
at 15.5% Moisture


Disease
Index 2/


Height, Ft.
Stalk Ear


Weight/
Bushel
Ibs.


Popping
Expansion,
Volumes


Normal
Expansion,
Volumes


Moisture
at
Harvest, %


Shelling
Percentage


C-1 Iy.
0-5-319
-51423
!S(RS) F1i
c-5-428
C-5-343
C-.4 y.
c-5-404
C-5-409
C-2-Hr
c-5-436\
C-5-331
C-5-330 \
0-5-332
South American


L.S.D. for; Yields: 0.5 =

C = Central Popcorn Coqr
Readings on May 16. Hi


1280 lbs.;


.01 1710 Ibs.


pany; IS(RS) MI is an open-pollinated
gher numbers indicate more injury.


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


variety from the Cuba Agri. Expt. Station.


indicates lateness. YS(RS) Fll harvested


4610
4260
3670
3670
3430
3110
2990
2990
2920
2750
2650
2640
2370
2330
1060


3.4
14.o
4.0
4.0
3.0
3.6
L.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
5.1
6.0
6.0
7.0
5.9
5.9
6.0
5.0
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
64.0
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
40.0
39.0
36.0
37.5
40.0
37.5
o40.
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
789.6
1.3
78.7


__ __


__







Table 5. The Characteristics and Performance of 19 Popcorn Varieties at Belle Glade, Florida. 1956
Yields Disease Height, Ft. Wt/Bu. Popping Normal Shelling Years Yield, Av.
Variety / Ibs./A @ Index Stalk Ear Lbs. Expansion, Expansion, Percent Grown lbs./A @
15.5 %/ Volumes Volumes Age Yrs. 15.5 %
3 C-l-HY 3085 1.9 6.0 3.3 65.7 36.0 36 84.1 4 3155
7 C-6-329 2750 2.1 6.3 3.1 67.0 35.0 36 81.8
2] P-31 2560 2.1 6.5 3.0 66.0 34.0 34 82.4 2 2080
12 C-5-401 2550 2.6 5.9 2.9 67.0 37.0 38 80.6
1 P-32 2515 2.3 6.5 2.6 66.0 34.0 35 82.8 2 2360
18 C-2-HY 2500 2.5 6.5 3.3 66.7 32.0 34 80.3 4 2270
4 C-55 2l35 2.3 5.6 2.8 65.0 34.0 35 81.5
9 C-6-343 2370 2.7 6.8 3.6 66.0 36.5 37 82.3
16 C-115 2370 2.1 6.5 3.5 66.3 33.0 35 83.3 3 2560
20 C-5-HY 2345 3.1 6.0 2.4 65.3 4O.0 39 82.3 3 1470
2 P-202 2335 1.4 5.1 2.9 66.0 38.0 38 78.5
11 C-6-117 2325 2.5 5.9 3.1 66.0 38.0 38 80.9
19 C-4-HY 2255 3.0 5.3 2.8 65.3 38.0 39 79.2 4 2345
5 C-6-303C 2140 2.1 6.0 2.8 66.0 35.0 36 82.1
13 S(BS)F11 2125 1.9 6.4 3.5 64.5 33.0 76.7 2 2900
10 C-6-l2 2065 2.8 5.6 2.6 65.0 37.5 38 85.1
8 C-6-337 1720 2.3 6.1 3.0 66.3 37.5 38 83.6
6 C-6-312 1450 1.6 6.1 2.9 65.6 33.0 37 77.9
15 0-105 1365 3.3 5.5 2.4 62.7 34.5 34 76.8 3 1675

No Significant Difference between Yields
2/ C Central Popcorn Company. YS(RS)F11 is an open-pollinated variety from the Cuba Agr. Exp. Sta. P = Purdue Hybrid
2/ Readings by Miss Alice L. Robert, FCRB, ARS, USDA on May 15, 1956. Scale 0-5. 0 = No injury.
Planted January 30, 1956 Harvested June 7, 1956









Table 6, Earworm Damage, Number, and Length
Belle Glade, Florida. 1956


of Popcorn Ears


Variety


Length of
Ear, nmn


c-6-329
P-32
C-l-HY
C-6-312
C-55
0-6417
P-31
C-2-HY
C-5-401
IS(RS)F11
C-6-1~12
P-202
C-6-337
C-4-H!
c-6-303c
0-115
c-6-343
c-5$-H
c-10$


18.4
16.1
14.7
16.2
17.3
16.0
17.1
16.6
16.5
18.0
16.4
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

85
1214
109
lo
104
125
125
102


a Scores joined by the same line are
Scores not joined by the same line


not significantly different from
are significantly different from


each other.
each other.


225 copies


% Worm-
Free Ears


Earworm
Score a


110
119
126
128
130
134
113
143
145

147
147
148
150
157
161
178
282