The morphological, productive, and phytochemical characteristics of three arnica wild populations (‘Giardino Botanico Paradisia’, Aosta; ‘Monte Bondone’ and ‘Malga Juribello’, Trento) were compared with cv. ‘Arbo’ carried out for four years in an experimental field situated at 990 m a.s.l. in the province of Trento, Italy. The morphological parameters were recorded from the 2nd to 3rd year of growing, while flower heads were harvested from the 2nd to 4th year. As regards the morphological parameters, the best results were obtained in the ‘Arbo’ variety (15.9 stems and 56.9 flower heads per plant), while the worst were in the ‘Giardino Botanico Paradisia’ population, which was not found to be suitable to the environmental conditions of the trial site. The dried flower head yield ranged from 15.9 (‘Giardino Botanico Paradisia’) to 53.2 (cv. ‘Arbo’) g m-2, with 47.5 and 9.8% of missing plants, respectively. As regards the years of growing, the highest yield was reached in the 3rd year, while the lowest in the 4th year. The sesquiterpene lactone, phenolic acid, and flavonoid content of the flower heads (2nd year of harvest) varied from 0.54 to 1.49%, 1.25 to 1.68% and 1.34 to 1.93%, respectively.
Keywords: flavonoids, flower yield, morphological characteristics, phenolic acids, sesquiterpene lactones