The purpose of the Iowa Corn Yield Test is to find for each district of the state those strains of corn which will produce the largest yields of sound grain. Significant differences in yield between strains grown in test fields under nearly as possible the same conditions may be attributed to differences inherent in the strain.
Robinson, Joe L. and Bryan, A. A., "Iowa Corn Yield Test, Results of 1934" (1935). Iowa Corn Yield Tests. 13.