Phytomass production from Silybum marianum for bioenergy.

Silybum marianum Gaertner is a herbaceous thorny member of the Compositae family common in the native flora of the Mediterranean basin. S. marianum seeds contain a complex substance called silymarin well appreciated for the treatment of human liver diseases and animal wellbeing. For its high aggressive vegetative growth causing depression of adjacent plants it is reputed as a dangerous weed in cropping areas. On the other hand, the rusticity and the high growth rates of S. marianum make it interesting for bioenergy purposes in rainfed Mediterranean environments. A research was started in Sardinia in order to evaluate the performances of this species in terms of biomass production under low input conditions. Data on undisturbed dry matter accumulation, yield, and phytomass partitioning into its components (leaves, stems and heads) were collected. The heating value and the energy balance of the crop were also assessed. The first year results are reported in this paper.