Genetic improvement of the BR 5033-Asa Branca corn cultivar in the Brazilian northeast region

Five cycles of selection were carried out among and within progenies of hal f-sibs on the BR 5033-Asa Branca corn cultivar, within the 1993 to 1997 per iod, in the Northeast Brazil, in order to obtain a germplasm more productiv e and better adapted to the ecological conditions of the region. The progen ies were evaluated in a lattice 14 x 14, with two replications, using the r ecombination in the same agricultural year, aiming to obtain a generation p er year. The genetic variability of the cultivar decreased as the cycles of selection advanced; this reduction was more pronounced in the cycles III a nd IV, when the selection was done in two and three places, respectively, a nd was less influenced by the interaction of progenies x places. The high m agnitudes of the genetic parameters have shown that the cultivar BR 5033 ha s a high genetic variability, that gives perspective of subsequent gains in the production by selection, that associated to a good yield and to its pr ecocity, makes this cultivar to be an important alternative for the agricul ture in the Northeast.