GGE biplot and regression based multi-environment investigations for higher yield and essential oil content in German chamomile (Matricaria chamomilla L.)

German chamomile is a highly valuable medicinal and aromatic herb lacking superior and stable varieties for varied environments in the western Himalayas. The study was conducted to estimate genotypic effects and their interaction with the environment under various conditions of Himachal Pradesh to identify superior and stable genotypes. For that, nine selections were evaluated at four different locations in randomized block design with three replications during 2020 and 2021. The combined analysis of variance showed significant genotypic effects for all the traits, while environmental and Genotype ×Environment interactions were significant for plant height, capitulum diameter, capitulum disc diameter, and fresh capitulum yield. The highest mean performance for most traits revealed that environment-2 has favourable conditions for German chamomile cultivation, and MC19005 was the best performer over all the locations. The stability parameters of the Eberhart and Russell model further confirmed that MC19005 is stable and superior for both fresh capitulum yield and essential oil content, again confirmed by Genotype and genotype by environment biplot analysis. Genotype and genotype by environment biplot analysis revealed that all the tested environments were formed a single mega-environment. The capitulum yield and essential oil content have a significant positive correlation and could be improved simultaneously in a single breeding program. Further, capitulum disc diameter and capitulum diameter would be the effective component traits for capitulum yield and essential oil content. The present study's results provide a strong base for identifying superior genotypes and selection strategy for future breeding programs in German chamomile. [Display omitted] •Environment-2 has favourable conditions for German chamomile cultivation.•MC19005 was the highest and stable performer over all the locations.•All the tested environments were formed a single mega-environment.•The capitulum yield and essential oil content has significant positive correlation.•Capitulum diameter and disc diameter were the contributing component traits.