The results of the Iowa Corn Yield Test are published as an aid to Iowa farmers in selecting corn hybrids adapted to their farms. This is the forty-fourth consecutive year for the Iowa Corn Yield Test since its beginning in 1920 and the fourth consecutive year in which a picker-sheller has been used to harvest a majority of the test fields.

Additional data are presented this year for high plant populations in tables 1, 6 and 12. The maturity trials at Ankeny and Kanawha include 2-, 3- and 4- year information for the first time. Soil fertility information of test fields is included for 1963.

The presentation of data does not imply approval or endorsement of any of the hybrids tested b y the authors or by the agencies sponsoring or conducting the test.