A half diallel cross between eight inbred lines of maize (Zea mays L.) was evaluated under two environments (artificial infestation and normal conditions.) in RCBD with three replications. Highly significant genotypes, parents and crosses were detected for the borer traits. General and specific combining (GCA and SCA) were found to be significant for all studied traits. Non- additive gene effects seem to play an important role in the expression of dead hearts %, intensity of damage, yield losses and grain yield/ plant at infestation and non infestation, where the ratio of GCA/SCA found to be less than unity for all traits. Regarding to grain yield/ plant the crosses P3xP5, P3xP6 and P3xP8 had significant superiority over the check hybrid SC pioneer 30k8 under both environments. Parent No 5 gave significant negative effects for percent of dead heart and percentage of resistance to susceptible plants and resistance to damage caused by S. cretica. P3 ranked the first best inbred line in grain yield/ plant in both environments. The best combinations were P3xP5, P3xP6, and P3xP8 for grain yield/plant at both environments |
