This bulletin reports the results of the 1956 Iowa Corn Yield Test. The purpose of the report is to provide information to help Iowa farmers select hybrids best adapted for the area in which they live.

The presentation of these results does not imply approval or endorsement of these hybrids by any of the cooperating agencies conducting the test.

The location of each test field and the division of the state into 12 districts is shown on the map (fig. 1). Each hybrid entry was accepted for testing in one or more districts and planted at two locations within each district. A total of 24 test fields were planted. Six test fields were not harvested because of severe drouth conditions. These were fields 1A, 4A, 5A, 7B, 9A and 10A. The name and address of each cooperator and the dates of planting and harvesting are listed in table A.

Plots were planted on land generally better than average for the area. However, there was no attempt to obtain the highest yield possible. Each cooperating farm operator used his customary cultural practices. We did try to locate each test on a field uniform in fertility, contour and past management to eliminate as much soil variation as possible.