The Iowa Corn Yield test has been conducted annually since 1920. The main purpose of the test is to provide information that will help Iowa farmers select seed of hybrids best adapted for the area in which they live. This bulletin reports the performance of hybrids tested in 1957. Also shown are comparisons of hybrids tested for 2-year, 3-year and 4-year periods.

The presentation of this report does not imply approval or endorsement of the hybrids tested by any of the cooperating agencies conducting the test.

Forty-three individuals or concerns made 1,019 district entries in 1957. These entries represented 319 corn hybrids. Each hybrid entry was planted at two locations within each district. Most of the entries tested were double crosses. Five 3-way crosses, four single crosses and one multiple cross also were tested.

All hybrids were entered by the producer of the seed, except those entered by the Iowa Crop Improvement Association. Only one entry of each closed-pedigree hybrids was permitted in each district. Only three open-pedigree hybrids were entered twice in the same district. These were Iowa 4470 in District 3, Ohio C92 in District 11 and AES 801 in District 12.