Effect of geographical origin and dimension of corms on saffron production in Basilicata Region (southern Italy)

Saffron, the dried stigmas of the Crocus sativus L. flowers, is the most expensive spice in the world. It is mainly used as herbal medicine, flavoring agent and food coloring, due to the content of 3 main secondary metabolites: crocin, picrocrocin and safranal. The influence on saffron yield of 3 classes of corm horizontal diameter, 2.0-2.5 cm (D1), 2.6-3.5 cm (D2) and 3.6-4.5 cm (D3), and 3 geographical corm origins, 'Sardinia' (Italy), 'Abruzzo' (Italy) and 'Kozani' (Greece), was evaluated in this study. For this aim, an experimental field, based on a split-plot design with 3 reps, was conducted in 'Genzano di Lucania' (40°50'N, 16°08'E; 344 m a.s.l., Basilicata Region, southern Italy) during 2015-2016. At harvest time, yield, flower number m-2, stigma length and stigma fresh and dry weight, were detected. Besides, at the end of crop cycle number and dimension of daughter corms were determined. Results indicated that both yield, and stigma length were affected by geographical origin and dimension of corms. In particular, the highest stigma yield (6.0 kg ha-1) was obtained by D3 'Sardinia' corms, followed by 'Abruzzo' and 'Kozani' (5.7 and 3.3 kg ha-1, respectively). The highest stigma length, 30.2 mm, was obtained by planting D3 'Sardinia' corms, followed by 'Abruzzo' and 'Kozani'. Moreover, D3 corms, at the end of crop cycle, generated more daughter corms able to flower (diameter >=2.5 cm) than D1 ones. According to this study, there is a positive correlation between corm dimension and yield, stigma length and daughter corms production. In order to achieve higher productivity of saffron, the use of 'Sardinia×D3' is considered the best option in Basilicata Region environment.