Using improved crop varieties is one of the best ways of getting the most for your money. Here are the crop varieties recommended for 1957. Each is backed by long and painstaking experiments and research.
Johnson, I. J. and Bragonier, W. H.
"Recommended Crop Varieties for 1957,"
Iowa Farm Science: Vol. 11
, Article 3.
Available at: https://lib.dr.iastate.edu/farmscience/vol11/iss7/3