The aim of the present study was to evaluate the following parameters of silage maize ear length: variability of inbred lines and their diallel hybrids, superior-parent heterosis and general and special combining abilities. According to obtained results of the two-year study, it can be concluded that variability of this trait is significantly affected by a genotype and a genotype x year interaction. As expected, hybrids had greater average values of ear length than inbreeds due to the depression of this trait that occurs in inbreeds during inbreeding.