The Iowa Corn Yield Test attempts to make available an impartial evaluation of various hybrid combinations in respect to yielding ability, lodging resistance, maturity and other agronomic characteristics. It is believed that the information presented in this bulletin may be of value to both the purchaser and the producer of hybrid corn seed, showing as it does the relative performance of various hybrids in different parts of the state. Data are presented on each entry for yield, stand, moisture, root and stalk lodging, dropped ears, ear height and damaged corn. A performance score has been used as a means of evaluating relative agronomic value of the different hybrids.