Estimation of genetic effects on economically important traits is a common procedure in the most breeding
programmes at Agricultural Institute Osijek. This paper deals with estimation of adequacy over
additive/dominance model of inheritance as well as estimation and comparison of genetic effects on plant
height for two specific pairs of inbreds (A672×Va99; A672×Os6-2), and its six basic generations (P2, F1, F2,
BCP1 and BCP2). Two year investigation was carried out at two locations in eastern Croatia. The trails
consisted of 121 entries of different inbreeding level derived by partial diallel mating design followed by
selfing and back crossing. Simple lattice experimental design was used in both investigated years. Goodness
of fit test results indicated the additive/dominance model failed to explain all differences among generation
means. Digenic epistatic model appeared to be adequate in both investigated pairs of inbreds at least in one of
the investigated years. Estimations and comparisons of genetic effects for selected pairs of inbreds and basic
generations revealed prevailing dominance effects when compared to additive