Ten Cycles of Progress from Modified Ear‐to‐Row Selection in Corn1

A modified ear‐to‐row selection program in corn Zea mayaL.) was initiated in Nebraska by Dr. J. H. Lonnquist in 1961. This paper describes results through the 10th cycle. Grain yields have continued to increase through the 10th cycle, but there is some evidence of curvilinearity. Part of this might be the result of a change in the selection criterion after the seventh cycle. At that time we began using a selection index that included lodging and dropped ears in addition to yield. The authors feel that it is unlikely that the selection study is plateaulng and therefore feel that linear regression estimates of gain are still appropriate. Gains in yield reported here from such an estimate are at the rate of 5.26% per cycle. Correlated responses in lodging, moisture at harvest, ear height, and number of ears per plant are discussed. Yield gains, though not very large, are still larger than those from mass selection in the same cultivar.