Agronomy and Plant Genetics 1888-2000 - Department of Agronomy ...

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the center of corn production in southern Minnesota. This expansion in
hybrid corn research made it necessary to develop later-maturing inbred
lines and to add staff at Waseca. Fortunately, the Waseca station had
enough land to support this expansion.
THE EARLY YEARS WITH EXPERIMENTAL
HYBRIDS: 1920-1925
Between 1920 and 1925 many Corn Belt states expanded programs
to capitalize on the background research by East, Shull, Hayes and Jones,
which led to conferences among staff to exchange viewpoints and update
their colleagues on progress. Not only were these early corn breeder conferences
important to those involved; they also established a new format
for exchanges of data and research concepts that ultimately became the
pattern for other crop conferences. During the 1930s the Hybrid Corn
Industry Research Conference became the first large-scale meeting for
public and private company corn breeders.
One can only speculate on how the future of corn breeding might have
developed during the 1920s without a small group of leaders – Hayes in
Minnesota, Stadler in Missouri, Lindstrom in Iowa, Kiesselbach in
Nebraska, Holbert in Illinois and Richey in the USDA. These early scientists
did not have the data from corn-breeding research available to those
who succeeded them.
During the early 1920s the expanding corn breeding program in
Minnesota, especially at Waseca, fostered the addition of Harvey
Brewbaker to the staff. He came as a graduate assistant with a B.S. degree
in 1921, completed the M.S. degree in 1923 and the Ph.D. degree with
Hayes in 1926. Hayes was becoming more deeply involved in wheat
breeding; adding Brewbaker relieved him of some responsibilities in the
corn project.
Several important facts emerged during this early period. Use of openpollinated
varieties as source material for inbreeding produced inbred lines
with many defects, such as susceptibility to lodging, generally poor vigor,
reduced pollen production and a wide array of single-gene or simply inherited
recessive abnormalities in chlorophyll production rarely observed in a
cross-pollinated variety. In the late 1920s the concept of testing inbred
lines to determine their general or specific combining ability had not yet
been used as a technique in corn inbred evaluation. Breeders observed that
some inbred lines consistently produced above-average performance in
crosses while other lines either performed poorly or were inconsistent. The
principle of difference in combining ability was recognized but unnamed. It
also was recognized that while the possibility of making diallel crosses