Yield and Stability for a 10‐Line Diallel of Single‐Cross and Double‐Cross Maize Hybrids¹

Abstract

A diallel of 45 single‐cross hybrids from 10 inbred lines of maize ( Zea mays L.), and a balanced set of 45 doublecross hybrids from the same inbred lines plus 10 commercial hybrids, were grown at 21 locations throughout the U.S. Corn Belt in 1965 and 1966. The purpose was to compare the stability of single‐cross and double‐cross hybrids. Two single crosses, as stable as any of the double crosses, were identified. These two single crosses outyielded the four commercial single crosses by 11%, and the three commercial double crosses by 13%. Although single crosses differed in their ability to respond to more favorable environments, the most important stability parameter appeared to be the deviation mean square. Since all types of gene action appeared to be involved in this stability, potentially useful single crosses must be evaluated over a wide range of environmental conditions to identify stable, high‐yielding single crosses for commercial release