The small centaury (Centaurium erythraea Raf.), like many members of the Gentianaceae family, are used both in preparing liqueurs and aperitifs and in phytotherapy, to stimulate appetite and to treat chronic dyspepsia. The dried herb yield of four accessions of small centaury, two collected from the wild (Valda and Grumes), the third bred locally (Gachof), the fourth of commercial origin (Jelitto), were assessed in two experimental trials, each lasted for two years (2005/06; 2007/08). The seedlings were transplanted (13.3 plant/m(2)) to a field 1009 m a.s.l. in the Province of Trento. At flowering phase, in both trials (2006 - 2008), the height (43-52 cm), the number of stalks per plant (6.3-5.7) and the number of divisions of the main stalk per plant (11.4-13.3) were recorded before harvest. in both years the dried herb yield of the local accession Valda was greater (19-20 kg/100 m(2)) than that of the other accessions that ranged about 10.5 kg in 2006 and 13.7 kg/100 m(2) in 2008 respectively. In 2006 the content (mg/g) of secoiridoid glycosides (gentiopicroside, swerziamarin and sweroside) and xantones both in the dried herb and roots was also measured. The dried herbs of Valda and Jelitto were the richest both in the single (swerziamarin) and in total content of active principles that approached 100 mg/g on average, followed by Gachof and Grumes (54 mg/g). In the roots a significant level of gentiopicroside was detected (average content 7.8 mg/g), and also small quantity of swertiamarin, sweroside and metossilate xantones (eustomin and desmetileustomin), substances typically found in the Gentianaceae family. The local accession Valda suits best both from the agronomical and from the pharmaceutical point of view.
