Selection of White Willow (Salix alba L.) and Chinese Willow (Salix matsudana Koidz.) for biomass production

Willows, compared with other species, are the most suitable for biomass production in short rotations because of their very strong growth during the first years. Nowadays, in Croatia, a large number of selected and registered willow clones are available. The main objective of the research should be to find genotypes which, with minimum nutrients, would produce the maximum quantity of biomass. In breeding the White Willow (Salix alba L.) and Chinese Willow (Salix matsudana Koidz.), methods of intraspecific and interspecific hybridization and back cross have been used and by cloning of plus variants from the hybrid families it was possible to make a selection of new genotypes that are suitable for biomass production. Clonal test of the arborescent willows include the autochthonous White Willow (Salix alba), interracial hybrids of the autochthonous White Willow and the English ‘cricket’ Willow (S. alba var. calva), interspecies hybrids (S. matsudana × S. alba), as well as multispecies hybrids of willows. The average production of dry biomass (DM ha-1 a-1) per hectare was estimated in regard to the clone, survival, spacing and the number of shoots per stump.