Iowa farmers no longer look upon hybrid corn as a new fangled idea that may or may not prove practical. Ten years ago less than 1 acre out of every hundred grown in Iowa was hybrid; in 1941, probably at least 95 acres out of every hundred are hybrid.
Sprague, G. F.
"Building New Corn Hybrids,"
Farm Science Reporter: Vol. 2
, Article 4.
Available at: http://lib.dr.iastate.edu/farmsciencereporter/vol2/iss4/4