Boxoffice-May.03.1952

REFRESHMENT
SERVICE
Research Program Produces Corn
With More Pop to the Pound
by JOHN C.
Theatre patrons enjoy tender, flavorsome popcorn and exhibitors earn
more concession profits because of greater popout of improved corn
ELDREDGE*
r OR HUNDREDS OF YEARS pcople have
eaten popcorn. But that was not because
it was good popcorn. It probably was used
because most any popcorn was better than
none at all. Even 20 years ago the popcorn
consumer had to put up with a distinctly
inferior product, measured by modern
standards. The popped kernel was coarse
and lacking in flavor. It had a thick, rough
hull which discouraged many people from
eating it. It was indeed a decidedly different
product from the modern tender, fluffy
flakes which the theatre patron now
munches while he enjoys a good picture.
Probably few popcorn consumers realize
how much patient, painstaking research has
gone into the development of the hybrid
popcorn of today. This program of popcorn
improvement was begun at Iowa State college
about 22 years ago.
The essential steps used in this
method
of popcorn improvement are as follows.
First, seed of the best available open-
'Dr, John C. Eldredge is associate professor of form
crops, Department of Agronomy, College of Agriculture,
Iowa State College, where a popcorn reseorch
progrom hos been in effect for the last 22 years.
pollinated varieties was planted in the
breeding nursery. At tasseling time the ear
shoots on the best plants were covered with
small transparent bags to prevent their
pollination by other plants in the field.
When the silks emerged and could be seen
under the bag, pollen was collected from the
tassel of the same plant and carefully
placed on the silks. These self-pollinated
ears then have controlled parentage, the
male and female both from the same plant.
The next year, seed from these individual
selfed ears were planted, each row from a
single ear. The process of self pollination
was repeated, always choosing the best
plants in the best rows. Controlled pollination
was continued for several years, usually
five or six, untO "pure lines" of corn were
developed. Lines become pure because by
inbreeding, the male and female parentage
of the seed always came from a single
plant.
CHARACTERS REMAIN UNCHANGED
As long as inbreeding is continued these
lines remain fixed or unchanged. Such
characters as sOk or tassel color, plant
Point of sole odrertising displays and wall signs like those shown below in the Rialto Theatre, Denver,
Colo., help increase popcorn sales. Gene Manzanares, manager (right), features buttered corn at 20 cents
a box, and at least half an ounce of melted butter is pumped into each patron's box.
height, time of maturity, popping volume,
and the hundreds of other characters reproduce
the same way from year to year.
But during the five or six years that the
pure lines were being developed by inbreeding
many undesirable as well as desirable
traits showed up. The desirable
lines, insofar as they could be recognized,
were saved and the undesirable ones were
discarded. Only a very few were good
enough in all characters to be saved during
the long period of intensive inbreeding.
This means that a large number of hand
pollinations were made every year. Many
lines were grown but discarded because
they had some fault such as low popping
volume, poor quality of popped corn, weak
stalks, or poor roots which caused the corn
to blow over easily.
A FORMIDABLE TASK
It must be obvious that large plots of
ground, much hand labor in planting,
weeding, pollinating, harvesting and shelling
was required each year. The task of
making popping tests, on the large number
of inbred lines developed, was a formidable
one.
But this was only the begiiming of hybrid
corn. After the inbreeding program had
been carried on for five or six years about
200 inbred lines had survived the rigorous
selection. But even the best inbred lines
were weak and the ears were small. They
could not be used for seed to produce a
commercial crop of corn for popping. To
restore the vigor and yield they lost during
inbreeding and to capitalize on the
good characters for which they were selected
these lines had to be crossed together
to produce hybrids.
REDUCED TO 20 LINES
However, 200 inbred lines are far too
many to cross in all possible combinations.
Nearly 20,000 could be made with 200 lines.
The number was then reduced to 20 by putting
the 200 through a special test by crossing
each one to the same parent. This test
shows which ones are likely to give the most
hybrid vigor. These 20 inbred lines were
then crossed in all possible combinations,
making about 200 single cross hybrids.
These 200 single crosses were tested in a
yield test to learn which hybrids showed
the most promise in making three-way or
double-cross commercial hybrids. This part
of the breeding work, to find inbred lines
that have the best chances of transmitting
their characters into hybrids that also
yield well, required hundreds of cross pollinations
made by hand, and thousands of
popping tests to measure volume and quality
of the popped corn. It is the intermediate
stage of cross breeding to reduce many
lines to only a few that met the exacting
demands of the producer and consumer of
commercial popcorn hybrids.
THEN CAME THE HYBRIDS
The third step in producing a good hybrid
popcorn was to make several hundred
experimental three-way and double-cross
hybrids from the most promising single
crosses. These hybrids also must be tried
Continued on page 18
The MODERN THEATRE SECTION