VARIATIONS OF THE CORN PLANT.
Whatever may have
been the origin of corn, the fact remains that in its distribution over the
United States it has undergone many and diverse modifications. Sturtevant
reports heights of stalks varying from 18 inches for Golden Thumb pop corn
to 22.25 feet for corn in Tennessee, and also reports individual ears with
rows of kernels varying from 4 to 48. Variations in color are almost
unlimited. Montgomery states that there are now probably 1,000 names
varieties of corn in the United States, three-fourths of which have been
developed since 1840. In 1898 Sturtevant listed 507 varieties.
Corn has shown especial adaptability to differences in length of
seasons, and at the present time we find varieties maturing in 80 days in
the North and other varieties requiring 150 days or more in the South. The
types, consisting of pop, flint, flour, dent, sweet, and pod corns, indicate
great changes in centuries of adaptation. In addition to their natural
variations, but few plants in America have received more attention at the
hands of the plant breeder than corn.
The plant breeder has found that plant to be very mobile,
responding readily to selection. Proof of this is shown by the fact that
selection has been found to influence the following characters: Shape of
ear, height of ear, percentage of protein, percentage of oil, type of
kernel, type of ear, width of leaves, color of kernel, size of cob, and many
other characteristics. Through hybridization, valuable characters of
different varieties have been brought together.