GENETIC-IMPROVEMENT OF THE BR-5028 - SAO- FRANCISCO CORN VARIETY AT THE BRAZILIAN NORTHEAST REGION

Four selection cycles were carried out among and within progenies of h alf-sibs on the population of BR 5028 - Sao Francisco corn variety in 1991, 1992, 1994 and 1995 at Neopolis and Lagarto, SE, Brazil. The wor k aimed at obtaining a higher productive and better adapted variety fo r the region environment. The progenies were evaluated on a 14 x 14 la tice design, with two replications. Recombination of the outstanding p rogenies was processed within the same year crop in order to get one c ycle per year. The values of the genetics parameters decreased with th e proceedings of the selection cycles; such reduction was more evident at VIII and IX cycles when progenies evaluation started to be conduct ed at two sites, having weaker influence of the progenies x environmen t interaction. The high magnitudes of the genetic parameters associate d with the high productivity means of progenies and with the expected averaged gain from the selection among and whithin progenies per selec tion cycle (29,8%) show the high potential of the variety to respond t o selection, which will permit to attain a higher production and a mat erial better adapted to the regional environment.