Adaptabilidade e estabilidade de cultivares de trigo nas mesorregiões do Campo das Vertentes e sul/sudoeste de Minas Gerais

Abstract

The mesoregions of Campo das Vertentes and Sul/Sudoeste de Minas have a significant participation in wheat farming in the state of Minas Gerais. Due to the large macroenvironmental diversity within them, it becomes necessary to evaluate in different growing environments in order to improve assertiveness and reduce the risk of cultivar recommendations. Thus, the objective of this study was to evaluate the adaptability and stability of wheat cultivars from different breeding programs in two mesoregions of Minas Gerais over different agricultural years. Nine experiments were conducted under rainfed conditions: six in the Campo das Vertentes mesoregion (Lavras, Itirapuã, and Itutinga) and three in the Sul/Sudoeste de Minas mesoregion (Lambari and São Gonçalo do Sapucaí). Sixteen wheat cultivars were evaluated in a 4 x 4 lattice design with three replications in the agricultural years of 2022 and 2023. Plant height (PH), thousand-seed weight (TSW), hectoliter weight (HW), grain yield adjusted to 13% moisture (GY), and grain yield index adjusted to HW (GYHWI) were evaluated. The data were analyzed using mixed models in the R environment. Several models with spatial correction were tested, and the best model was chosen based on Bayesian Information Criterion. Subsequently, Annichiarico's method GGE biplot, and multi-trait adaptability index (MTSI) were performed to evaluate cultivar adaptability and stability. Spatial correction provided improved precision, with relative efficiency between 118% and 196% in different environments. Significant differences were found among cultivars, agricultural years, and locations for all traits. The cultivar x location interaction effect was more pronounced than the cultivar x year interaction. Using Annichiarico's method, no cultivars superior to the checks (BRS 264 and TBIO Aton) were observed based on GY and GYHWI. In the GGE analysis, PH, HW, and TSW showed similar behavior in the tested environments, with no identifiable mega-environments. However, for GY and GYHWI, possible mega-environments were formed. The cultivar highlighted for PH was MGS Brilhante; for HW and TGW, it was BR 18; for GY, ORS Soberano, ORSSENNA, and TBIO Aton stood out; and for GYHWI, BR 18, ORS Soberano, TBIO Aton, and ORSSENNA stood out. Itutinga was one of the most discriminative and representative environments for GY. Cultivars selected based on the MTSI index were ORS Soberano and ORS Absoluto. The G x A interaction was mainly attributed to the interaction of cultivars with locations. Mega-environments were identified for GY and GYHWI. The simultaneously most representative and discriminative environment was Itutinga in 2023 for GY and YIHW.