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.

The aim of the present study was to evaluate the following parameters of maize grain yield: 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, year and their interaction. As expected, hybrids had higher average grain yields than inbreds due to the depression of this trait that occurs in inbreds during inbreeding.

Historically speaking, both the introduction of double-cross hybrids and use of single crosses have caused the increase in grain yield and significantly improved agricultural practice. Nowadays, the uniformity of crops is regarded as an advantage of modern agriculture, since the uniformity of products is crucial in global market. Thus, uniformity of crop maturation provides both planning and efficient mechanized harvest. F₁ single-cross hybrids of maize, which is an allogamous species, not only exploit heterosis, but also impose homogeneity.