Everglades Station Mimeo Report 63-7
POSSIBILITIES OF UTILIZING VARIETIES OF
FIELD CORN WITH SWEET STALKS
Victor E. Green, Jr. 1/
At the mention of sweet stalks, most readers will immediately think of
sugarcane or sweet sorghum. However certain varieties of field and sweet corn
have sweet, juicy stalks. John J. Finan, in his Maize in the Great Herbals,
Chronica Botanica Co., Waltham, Mass., 1950, makes available a facsimile from
the herbal of Hieronymus Bock, Neu Kreuterbuch Von Underscheid, Strassburg, 1539,
wherein is stated that the large round stalks of maize, when they are still
green, are juicy and sweeter than any sugar.
Paul Weatherwax, in his Indian Corn in Old America, Macmillan Co., N.Y.,
1954, has a section on maize as a source of sugar. He stated that the pith of
corn stems contains considerable sugar, and remains juicy and sweet until the
ear draws on this supply of food for grain development. He remarked that even
today in Indian Villages children may be seen chewing and sucking the juice from
cornstalks just as they do from sugarcane. He quoted from Pinkerton's Voyages
and Travels 13: 1-205, wherein Captain John Smith wrote in 1624, in his history
of Virginia, "The stalk, being green, hath a sweet juice in it, somewhat like the
sugar cane, which is the cause that, when they gather their corn green, they suck
the stalks......". He also quoted from Garcilaso de la Vega's El Inca, 1869-1871,
Royal Commentaries of the Incas, London, who wrote, "From the stalks, before the
grain matures, is made a very fine syrup; for the stalks are sweet".
Willaman, Burr and Davison (3) studied the possibilities of making syrup
from sweet corn stalks as a by-product of the canning industry in Minnesota in
the mid-1920s. At the canning stage of maturity, the sweet corn stalks had a
Brix reading of 9 to 110. Ten to 20 days after ear removal, sweetness of the
stalks had increased to 13-170 Brix. The juice of stalks where ears were not
removed did not increase in density.
In 1930, Welton, Morris, and Hartzler (2) fo t hat dry m r and sucrose
were larger in the upper part of the corn stem th n jfAhe lower\ t and that
percentage reducing sugars decreased from tassel lng Wma4 rity.
In 1931, Sayre, Morris and Richey (1) report on the efft of preventing
fruiting and reducing the leaf area on the accumul tin of sugar i; the corn stems.
The Burr-Leaming Variety, where pollination was preeOt on S "ember 23
_/ Associate Agronomist. The author acknowledges the assistance of Mr. Norris
McKinney and Mr. Robert M. Fliehs, Field Assistants, Experiment Station, who
made the weekly hand refractometer -readings, and Mr. P.S. Francis, Chemist
and Dr. B. A. Bourne, Vice President, Research, United States Sugar Corpo-
ration, Clewiston, for analysis of the juice of the sweet stalk corn. The
seed of varieties of sweet-stalked corn were furnished by Mr. Leon Steele,
Director of Research, Funk Bros. Seed Co., Bloomington, Illinois through Mr.
Foy Campbell, Asst. Sales Mgr., La. Seed Co. of Miss., Inc., Montgomery, Ala.
reached a total sugar content of 10.5%. Normal plants had 9.0% on September 11,
decreased to 7.9% by September 23. Reducing the leaf area lowered the total
sugar content of the stems. Sucrose content of normal stalks was 6.54%; of
barren stalks 9.87%.
The sweet stalk characteristic of certain varieties of corn immediately
suggests possibilities of utilization in the area.
FOR SUGAR In south Florida, sugarcane is unexcelled as a crop for sugar pro-
duction. Its perennial habit and relative resistance to insects and diseases
almost certainly preclude the use of sweet stalk corn as a source of sugar dur-
ing the normal grinding season. It might, after much further research, be used
to extend the grinding season on each end, viz. before late October and after
mid-April. Both these times are during the normal wet season when corn might be
better than sugarbeet which makes its sugar underground. The same governmental
controls would probably apply to corn as apply to cane for sugar production.
Sweet stalk corn can be harvested mechanically.
FOR SYRUP It is doubtful whether the market for syrup would justify the use of
sweet stalk corn for that purpose. This area already has the capacity of pro-
ducing more sugarcane syrup then it can sell.
FOR SILAGE AND FRESH CHOPPED FORAGE J. C. Anderson 2/ stated that in N.J. bird
damage in some areas amounts to 60% of the potential grain yield. A 1961 ex-
periment was conducted to determine the loss of total dry matter in barren and
normal corn. Barrenness resulted in a loss of about 25% dry matter. He found
that dry matter increases relatively little after 42 days from mid-silk for
either barren or normal plants. Sucrose equivalent reached a maximum at 56 days
past mid-silk for barren plants and 14 to 28 days for normal. He stated further
that corn plants with grain will, on the average, produce more total dry matter,
total N, and total estimated energy in therms per plant then will barren plants.
However, barren plants will, on the average have higher dry matter digestibility
by the artificial rumen method and higher percent protein in the stover.
David L. Matthews 3, stated "No research has yet demonstrated conclusively
that other crops, or different corn management practices, will consistently pro-
duce more digestible nutrients then ensilage from conventionally grown corn."
Corn breeding programs in the past few decades have emphasized the formation
of hybrid varieties, having but one ear, on short, disease-free stalks. Recently,
studies have been made on corn with high amylose and/or high protein in the grain,
but little or no thought has been given to increasing the sugar content of the
stalk. However, the Funk Bros. Seed Co. have made up a number of test crosses
that are cytoplasmically male sterile. If these are planted with the necessary
isolation, the plants will be automatically barren of seed. The tassels and ear
shoots form, but no grain is produced. These lines were used in the summer 1962
2/ Anderson, J.C. Barren vs. Normal Corn for Silage. Report of the 17th NE
Corn Improvement Conference. N.Y. Feb. 23-24, 1962. CRD-ARS-USDA CR-25-62.
March 1962. pp. 2-5.
_/ Matthews, David L. Drilled Corn for Silage. Ibid. pp 6-8.
The north side of Field 5NW, which had been in sugarcane for about 10 years
and field corn for 2 years, was used for the test. The soil was plowed, disked
and fertilized with 400 Ibs./A. of a 4-12-16 containing 1% each CuO, MnO, B203,
and ZnO with 100 Ibs. per ton of 25% Aldrin, applied broadcast and immediately
disked in on February 4, 1962. Each of 5 Varieties was planted on February 23
in 2 adjacent rows, running the length of the field east and west, with a corn
planter set to drop seed every 9 inches. Cutworms and budworms were controlled
by two sprayings of 2 Ibs. of actual toxophene and 1/4 lb. of actual endrin in
100 gallons of water per acre, and one spraying of 12- quarts of 25% DDT in 100
gallons of water per acre. Three cultivations controlled the grassy and broad-
leaf weeds. Four varieties had a tasselling mid-point on May 2, or 68 days after
planting; one variety on May 10, or 76 days after planting. Stalk heights of the
plants of the various varieties and their attendent "ear" heights in inches were
1) 94/62 for the late variety, 2) 84/42, 3) 85/51, 4) 86/43, and 5) 80/40. The
control variety, Funk G-745, tasselled 86 days after planting, or on May 20. The
ears were 49 inches off the ground on stalks 90 inches tall.
To determine "apparent sucrose", a TOKO Model 1, 0-32% hand refractometer /
was used. Every Monday morning between 9 AM and 10 AM for 5 weeks (on May 28,
June 4, 11, 18 and 25), 5 stalks were tested in each variety by crushing a few
drops of juice from the internode directly below the ear-bearing node with a pair
of pliers. The juice was squeezed out directly onto the refractometer. The
control variety, Funk G-745 was similarity treated, the first reading occurring
only one week after tasselling. Readings did not proceed beyond May 25 because
the stalks were too dry, and no juice could be extracted by this method.
Figure 1 shows the degrees Brix of the juice of the varieties plotted
against the date. The 4 cms varieties that tasselled early reacted fairly
regular to accumulations of sugar in the stems. The varieties in Rows 3-4 and
9-10 had sucrose contents that rose and fell together during the season, with
3-4 in the 13 to 140 range and 9-10 in the 14 to 160 range. Neither variety
reached a peak before drying took place in the stalk. The highest average read-
ing obtained was in Rows 9-10, amounting to 16.3 Brix on June 25. Individual
readings were 15.0, 16.0, 16.2, 17.0 and 17.4.
The variety that tasselled late, in Rows 1-2, was very erratic in sucrose
accumulation. Starting at only 9.60 about 18 days after the mid-point of
tasselling, it increased for 2 weeks to peak at 13.40, dropped during the next
week to 8.8, then rose to 11.3 during the next week.
The double-c6oss hybrid, Funk G-745, allowed to field pollinate itself,
never reached 9.0 Brix. For 3 out of the 5 weeks, it was below 8.0 .
On June 27, 1962 a 25-stalk sample of the variety in Rows 9-10 was stripped
of its leaves, the tassels removed, and was sent t9 the United States Sugar Corp-
oration at Clewiston for analysis. Their report showed that the weights of
4/ Available from Florida Import and Distributing Co., Box 851, Maitland, Fla.,
@ $40 in April 1962. An almost indistinguishable instrument, the Lafayette,
is available from Sugarland Chemicals, Inc., Belle Glade, Fla. @ $43 in
5/, Private Communication from B. A. Bourne, Vice-President, U.S. Sugar Corp.,
Clewiston, Fla., dated July 5, 1962.
....- ._ ..5-6
The apparent sucrose content of stalk juice of 6 field corn varieties planted
February 23, 1962, Belle Glade, Florida and sampled on the dates indicated.
the milled sample was 18.4 Ibs. The stalks were doubled over and passed through
the small mill again after the first milling. The yield of juice was 9.0 lbs.
and of moist bagasse 9.4 Ibs, giving a juice extraction of 48.9%, a figure,
according to Dr. Bourne, comparable with some of the small-barreled, high-fiber
sugarcanes. Analytical data made by Mr. P. S. Francig, their chemist, on the
composite juice sample showed a pH value of 5.3, 17.0 Brix, 12.19% sucrose
(polarization), 71.71% purity and 2.35% invert sugar.
Yields of millable stalks were not calculated in this preliminary test.
Future plantings will be made on rows 3-feet apart with plants every 4 inches in
the drill, or 43,560 plants per acre. The varieties used in the 1962 test were
too early, that is, they tasselled too early, restricting the size of the stalks.
In addition, varieties for use in the Everglades must possess a high degree of
resistance to northern leaf blight, that often occurs here as an epiphytotic.
1. Sayre, J. D., V. H. Morris, and F. D. Richey. The effect of preventing
fruiting and of reducing the leaf area on the accumulation of sugars in
the corn stem. Jour. Amer. Soc. Agron. 23: 751-753. 1931.
2. Welton, F. A., V. H. Morris, and A. J. Hartzler.
dry matter, and sugars in the maturing corn stem.
Distribution of moisture,
Plant Physiol. 5: 555-
3. Willaman, J. J., G. O. Burr, and F. R. Davison. Cornstalk syrup investi-
gations. Minn. Agr. Exp. Sta. Bul. 207. 1924.