Evaluation of corm origin and climatic conditions on saffron (Crocus sativus L.) yield and quality

BACKGROUND: Crocus sativus L. is an autumn-flowering geophyte belonging to the Iridaceae family, known for the medicinal and coloring uses of the spice from its dried stigmas. It is cultivated in countries with different pedoclimatic conditions. This paper reports on a two-year research project carried out in the Basilicata region of southern Italy on the question of how to obtain the highest performance from saffron. It considers corms from three different geographical origins – ‘Sardinia’, ‘Abruzzo’ and ‘Kozani’ at three different cultivation sites, namely Castelgrande (40° 46′ N, 15° 26′ E, 781 m a.s.l.), Genzano di Lucania (40° 50′ N, 16° 08′ E, 344 m a.s.l.), and Villa d'Agri (40° 22′ N, 15° 48′ E, 638 m a.s.l.). RESULTS: The highest yields were obtained in the second year by the combination of ‘Genzano di L. × Sardinia’ and ‘Castelgrande × Abruzzo’ with 28.1 and 23.9 kg ha−1 of dried stigma, respectively. Saffron quality was determined according to ISO 3632, which classifies the samples into three categories depending on the crocin, picrocrocin, and safranal content. Results highlighted that the highest values for coloring (242.1) and bitterness (97.7) were achieved in Genzano di L. during 2013. Moreover, the crocins were correlated positively with stigma yield and air mean temperature but negatively with safranal. CONCLUSION: This study demonstrated, through principal component analysis (PCA), that the cultivation site with higher air temperature and without excessive rain during the flowering period generated the best stigma yield with high-quality traits.