RECIPROCAL DIFFERENCES FOR FORAGE TRAITS IN SINGLE AND 3-WAY CROSSES OF MAIZE

Eleven flint inbreds of maize were crossed with 11 dent inbreds accord ing to a balanced incomplete factorial mating design to produce 66 sin gle crosses (2W) in both reciprocal forms. Additionally, six three-way crosses (3W) were also produced in both reciprocal forms. These hybri ds were evaluated for 11 forage yield and quality traits in 1983 and 1 984 at three sites in Germany. Highly significant reciprocal differ en ces were observed for nine traits in the 2W. The respective variance c omponent estimates amounted to 2-33% of the variance component due to crosses. On average, flint x dent 2W had lower dry-matter content (DMC ) than dent x flint 2W and a 1% greater dry-matter yield (DMY) of fora ge. Three-way crosses produced on singles exhibited greater DMC (3%) a nd DMY (5%) of the ear, metabolizable energy content (MEG) of stover ( 1%), and DMC and DMY of forage (2%) than their reciprocal forms produc ed on lines. Based on this study, because of their minor importance, r outine testing for reciprocal differences among 2W hybrids is not reco mmended.