Environmental adaptability of perennial cotton in the Seridó

Abstract

The cotton economic depression, enlarged with the boll weevil appearance, decreased the cultivated area in Rio Grande do Norte, Northeastern Brazil, in 80%. Five perennial cotton genotypes (Gossypium hirsutum (L.) r. marie galante, Hutch.) have been tested as to yield stability and environmental adaptability, in five environments of the Seridó microregion in Rio Grande do Norte state from 1987 to 1990 in a completely randomized block design with ten replications. The yield data were analyzed for linear regression to estimate the genotype x environmental interaction. All genotypes showed yield stability and were arranged in three groups as to the environmental adaptability. The CNPA-4M cultivar and the CNPA 85-5-SRF₅ - C 75 mixture presented wide environmental adaptation. The CNPA-3M cultivar showed mean environmental adaptability and the CNPA-2M and EMPARN-2 cultivars did not show any environmental adaptation.