Productivity of willow coppice plants grown in short rotations.

In the paper yield of dry ma�er and some morphological features of four fast growing willow coppice genotypes harvested in one, two, three and four years harvesting cycles are presented. In the experiment an average yield amounted to 16.79 t/ha/year. The highest yield was recorded for Salix viminalis × S. viminalis lanceolata (22.89 t/ha/year). Genotype Salix triandra gave a yield lower by factor 3 compared to Salix viminalis × S. viminalis lanceolata. For the following genotypes: Salix viminalis × S. viminalis lanceolata, Salix viminalis var. gigantea and Salix viminalis var. regalis it was found the yield increased as harvesting cycle increased from one to four years while the opposite was found for genotype Salix triandra. It can indicate that Salix triandra is not suitable for intensive growing on arable lands, especially in two, three or four years harvest cycles. Mean plant height amounted to 4.63 m and stem diameter 20.48 mm. The tallest plants (769 cm) with the thickest stem (diameter of 37.43 mm) were found for genotype Salix viminalis × S. viminalis lanceolata harvested quadrennially. At harvest water content amounted to 49.87% and the highest value was found for the shortest harvesting annually.