Genótipos de arroz de terras altas em ambiente de sucessão de culturas

Abstract

Grain production systems in Brazil are predominantly based on the soybean - maize succession, a model that, although highly productive, presents limitations associated with low agroecosystem diversification and increased vulnerability to environmental conditions. In this context, upland rice has emerged as a promising alternative for diversifying agricultural production systems, particularly during the second crop season. This thesis aimed to evaluate the potential of upland rice for cultivation during the second crop season through a literature review and the phenotyping of elite breeding lines to identify productive, early-maturing, widely adapted, and stable genotypes across different sowing dates. The thesis was organized into two chapters. The first chapter consisted of a literature review addressing the integration of upland rice into production systems, highlighting its agronomic, environmental, and economic benefits. The second chapter comprised the phenotypic evaluation of elite breeding lines conducted during the 2023, 2024, and 2025 second crop seasons under different sowing dates. The AMMI, GGE Biplot, WAASB, and WAASBY methodologies were employed to assess genotype adaptability and stability. The results revealed substantial genetic variability, enabling the identification of genotypes with high grain yield potential, earliness, broad adaptability, and high stability. The integration of these methodologies improved the accuracy of genotype recommendations for different cultivation conditions. Overall, the findings demonstrate that the inclusion of upland rice in the second crop season is a promising strategy for diversifying production systems, enhancing agricultural sustainability, and supporting breeding programs as well as cultivar recommendations for different environments, particularly under second growing season conditions.