The Iowa corn yield test is conducted annually to provide impartial comparable performance records on a relatively large number of hybrid combinations. Each hybrid tested is ranked by a performance score based on yield, dry matter content of grain, lodging' resistance and the percentage of ears held on the stalks.

In view of the present world food need, it is important that farmers plant hybrids adapted to their particular locality. The information. presented gives a reliable estimate of the relative performance of a considerable number of hybrids when grown in different areas of Iowa.