Abstract
Genotype-by-environment interaction (GEI) significantly impacts the success of plant breeding strategies in various crops including the cool-season annual crops such as chickpea (Cicer arietinum L.). In this study, advanced trials of 15 spring chickpea genotypes were tested at three locations for multiple years in the Pacific Northwest region of the United States. The normalized difference vegetation index (NDVI), green NDVI (GNDVI), and soil adjusted vegetation index (SAVI) were extracted from unmanned aerial vehicle-based multispectral images at flowering and early pod development. The genotype, environment, and GEI effects on the vegetative indices were evaluated, and compared with those on yield. The G × E models evaluated were the additive main effects and multiplicative interaction (AMMI) and genotype-environment interaction (GGE) biplot. The associated metrics utilized in the study included AMMI stability value (ASV), and genotype stability index (GSI). There were significant genotype and environment effects (p < 0.001) for seed yield and vegetation indices. GEI effects were significant for seed yield, GNDVI at flowering, and SAVI at early pod development. The AMMI, GGE, ASV, and GSI analysis identified two genotypes (G10 and G12) as stable, high-performing genotypes based on seed yield, GNDVI at flowering and SAVI at early pod development data. The findings revealed that the vegetation indices can potentially be valuable, in addition to seed yield, to measure the genotypic performance and the GEI effects of chickpea cultivars. Such evaluation of the GEI effects on crop performance with additional metrics can enhance the variety selection process in the plant breeding programs.