GRAIN-YIELD STABILITY OF IRRIGATED RICE I N ALAGOAS AND PERNAMBUCO STATES

From 1986/87 to 1990/91, the performance of eleven irrigated rice geno types were studied and evaluated in Pernambuco and Alagoas State, in B rasil. The main objective of this work was to study the genotypes envi ronment interaction and the phenotypic stability to grain yield. The e xperimental design was casualized blocks with three replications and e leven treatments. The grain production responsed to environmental vari abilities in a predominantly linear form. On this way, the genotypes E PEAL 101, EPEAL 102 and CNA-4899 showed the greater stability in relat ion to grain yield, with good conditios to response introduced changes into environment. The genotypes CNA-4893, CNA-3916 and METICA 1 showe d significative difference concerning to regression coefficient, ratif ying low stability to grain yield. The genotype EPEAL 101 became the m ost promissory one in the study of stability, even showing a low produ ction of grain. On the other hand, the genotype EPEAL 102 was the most productive in grain (8.469 kg/ha) and the CNA-3916 presented the wors t performance (7.122 kg/ha).