Growth of bracken in Denmark and the content of ptaquiloside in fronds, rhizomes and roots.

Abstract

The growth and ptaquiloside content of the fronds, rhizomes and roots of bracken (Pteridium aquilinum) in Denmark were studied. The fronds reached maturity 97-134 days after emergence from the ground. The longest fronds measured 166-212 cm and the highest density was 9-14 frond/m². A total aboveground biomass production between 163 and 496 g/dry matter/m² was estimated at the end of the growth season. Ptaquiloside was detected in all plant part tested. The fronds recorded 360-3612 µg/g, whereas the rhizomes recorded 2-7046 µg ptaquiloside/g. The storage rhizomes had higher ptaquiloside content than the frond-bearing rhizomes, particularly in autumn. The ptaquiloside content in the roots was generally lower compared to the other plant part tested.