Termos para indexação: interação genótipos x ambientes, variedades, híbridos. ADAPTABILITY AND BEHAVIOUR STABILITY OF CORN CULTIVARS AT THIRTEEN ENVIRONMENTS OF BRAZILIAN NORTHEAST COASTAL TABLELANDABSTRACT -The potential of the Brazilian Northeast coastal tablelands for corn production and the adaptability and stability of sixteen corn cultivars were evaluated at thirteen environments of this region in 1994/95 on a randomized block design experiment with three replications. The large potential of this coastal strip for corn production was evidenced by the obtained yield, highlighting the hybrids, on the coastal tablelands of Piauí, Sergipe and Bahia States, where corn would become a major crop option for the growers. Pooled variance analysis showed significant difference for environments and cultivars, and the interactions environment x cultivar, which were inconsistent. Hybrids had better adaptation than varieties and populations; they are recommended for higher input situations. The AG 510 hybrid showed good adaptation to low and high input conditions, and therefore is recommended for both situations. The BR 5011, BR 5028, BR 106 and BR 5033 varieties had reasonable yields and are suitable for small and medium corn growers.Index terms: interaction of genotype x environment, varieties, hybrids. INTRODUÇÃOOs tabuleiros costeiros ocupam todo o litoral do Nordeste brasileiro; tem uma área estimada de 8,420 milhões de hectares, e neles se constata grande diversidade de solo e clima (Embrapa, 1994). Nessa região, tem-se observado um incremento considerá-vel na demanda pelo milho, em razão da alta densidade demográfica e do crescente aumento da explo-1 Aceito para publicação em 13 de abril de 1999.

The aim of this study was to identify inbred progenies of S maize (Zea mays L.) plants that were efficient at a low level of technology and responsive at a high level of technology through the use of topcrosses. Two contrasting environments were created using two levels of base fertilization and topdressing, so that the levels of nitrogen, phosphorus, and potassium were applied four times higher in one environment than in the other. We used S progenies derived from commercial hybrids in topcrosses with two testers (an elite line from the flint heterotic group and an elite line from the dent heterotic group). The progenies and three controls were evaluated in an augmented block design in Nossa Senhora das Dores, SE, Brazil in the 2010 crop season. The average grain yield in the high-technological level was 21.44% greater than that in the low-technological level. There were no changes in progeny behavior in the two technological levels for grain yield. The testers did not differ in the average grain yield of the progenies at the two technological levels. Therefore, it is possible to select progenies derived from commercial hybrids that have an efficient response to fertilization.

) inferior a 80%, o que confere a todos eles uma boa estabilidade de produção.Termos para indexação: Zea mays, interação genótipo x ambiente, diferenças genéticas, híbridos, variedades. ADAPTABILITY AND YIELD STABILITY OF SOME MAIZE CULTIVARS IN THE BRAZILIAN NORTHEASTABSTRACT -Twenty five cultivars of maize (Zea mays L.) were evaluated in 1994, in twelve different environments of the Northeast Region of Brazil. The trials were arranged in randomized block designs with three replications aiming to obtain knowledge concerning to the adaptability and yield stability of the cultivars in each environment. The significant effects related to environment, cultivars and cultivars x environments interaction gave the evidence of outstanding differences among that parameters. The hybrids showed better performance than the varieties, yielding in average 22.5% higher in relation to the environmental variations. Only the Cargill 505 and AG 510 hybrids showed poor adaptability in unfavorable environments. Taking in account the means presented by the varieties, CMS 39 was the most adjusted to the optimal genotype proposed in the model. None of the materials studied gave a determination coefficient (R 2 ) lower than 80%, indicating a good production stability.