Genetic parameters estimates for ear weight in "Flint Composto Nordeste" maize population

Abstract

In the years of 1974/75, 1975/76, 1976/77, 1977/78, three cycles of selection among and within half-sib families were realized with Flint Composto Nordeste maize population, in order to obtain genetic parameters estimates for ear weight and to verify its genetic variability. Five trials, 10 x 10 duplicated simple lattices, with one replication per location, were performed. Genetic variability, expressed as the magnitude of the additive genetic variance decreased from cycle O to cycle I, standing almost constant for the following cycles selection. Similar trend was observed for the magnitudes of the genetic coefficient of variation. Mean expected genetic gain per cycle was 6.16% and the mean observed gain was 5.09%. The favorable yield performance shown by the population was an indicative of enough genetic variability. It is advisable, however, to use higher selection intensities for selection among families in the next cycles.