Forage production and essential oil content of Psoralea bituminosa and P. morisiana accessions

Fifteen accessions of Psoralea bituminosa, belonging to the botanical var. albomarginata, crassiuscula and bituminosa, and P. morisiana of Spanish and Sardinian origin were studied for their forage yield and essential oil content and composition. The accessions showed different total and seasonal forage production, reaching the maximum value of 500 g fresh weight per plant in P. bituminosa 'Calnegre'. The essential oil content ranged from 0.003% to 0.054% of leaf fresh weight. The essential oil composition of accessions varied in function of the species, the botanical variety and their origin. The number of identified oil components was 66 in P. bituminosa bituminosa, 47 in P. bituminosa albomarginata, 51 in P. bituminosa crassiuscula, and 59 in P. morisiana, representing at least 92% of total components in each oil. Caryophyllene oxide and ?-caryophyllene, Z-?-farnesene e D-germacrene and long-chain alcohols were the most abundant components. The good forage production and low essential oil content are positive factors for the use of Psoralea as forage.