Impact of environmental covariates on genotype-environment interactions in a semi-arid region of Rio Grande do Norte State, Brazil

Limited knowledge exists on the impact of environmental covariates on the genotype-by-environment (G × E) interaction in melon cultivated under semi-arid conditions. This study assessed the influence of environmental covariables on G × E interactions and identified melon genotypes demonstrating adaptability and stability. Thirteen yellow melon hybrids were evaluated in randomized blocks with three replications across four municipalities in Rio Grande do Norte State during two distinct seasons. Traits investigated included the number of fruits per plant and soluble solids. Factor regression and principal component analysis were employed to quantify the influence of maximum and minimum temperature, relative humidity, and radiation on the G × E interactions. The Harmonic Mean of Relative Performance of the Genotypic Values method identified adapted and stable genotypes. The covariate-biplot model established relationships between crucial environmental covariables and their impact on the number of fruits per plant and soluble solids. Minimum temperature, relative humidity, and solar radiation significantly contributed to the G × E interactions in melon. Hybrids exhibited distinct sensitivities to environmental covariates, with HA-08 emerging as the most stable and adapted hybrid for both the number of fruits per plant and soluble solids.