Groundnut rosette disease (GRD) is a major constraint to groundnut production in sub-Saharan Africa, causing severe yield losses, particularly under low-input smallholder farming systems with limited access to external inputs. Because resistance to this pathogen is strongly influenced by environmental factors, quantifying genotype-by-environment (G×E) interactions is essential for identifying GRD-resistant varieties and optimal testing locations. This study analyzed the effects of genotype (G), environment (E), and their interaction (G×E) on GRD resistance and grain yield of groundnut in northern Mozambique. Twenty advanced groundnut lines (Arachis hypogaea L. ) were assessed across 11 environments from 2014 to 2018 using an alpha-lattice design with two replications under low-input conditions. Measured traits included phenology, number of emerged plants, number of plants at harvest, yield components, grain yield, and GRD incidence. General and mixed linear models, stability analysis, AMMI and SREG models, and Pearson correlations were applied. Significant G×E interaction was observed, indicating a strong environmental influence on trait expression. GRD incidence was highest in the NPL₁5 environment, where the susceptible cultivar JL-24 reached 56% and SREG analysis identified this site as a suitable hotspot for resistance screening. Genotypes ICGV-SM 7508, ICGV-SM 7510, ICGV-SM 7518, ICGV-SM 7533, ICGV-SM 7558, ICGV-SM 7566, ICGV-SM 8530 and ICG 405 showed resistance. No consistent relationship was observed between GRD incidence and grain yield; however, yield reductions were mainly associated with plant losses during the growing season. Genotypes ICGV-SM 7518 and ICGV-SM 7510 showed broad adaptation, combining high yield and GRD resistance across environments.
Bolacha et al. (Mon,) studied this question.