The Iowa corn yield test is conducted by the Iowa Corn and Small Grain Growers’ Association in cooperation with the Iowa Agricultural Experiment Station. The purpose is to compare the performance of hybrids that are offered for sale to farmers. We hope the information in this bulletin will help you to choose the best hybrids available for planting in 1950.

The state was divided into 12 districts, and a test field was planted in each district. The counties included in each district and the location of each test field are shown in fig. 1.

Each entry was planted in all three districts of a section. Eighty-one entries were planted in the northern section, 100 in the north central section, 81 in the south central section and 64 in the southern section. As shown in fig. 1, districts 1, 2 and 3 make up the northern section; districts 4, 5 and 6 make up the north central section, etc.