Biomass Production of Gigantic Grasses Arundo donax and Miscanthus × Giganteus in the Dependence on Plant Multiplication Method

The effect of plant propagation method on growth parameters and the yield of above-ground biomass in two species of gigantic grasses were measured during three growing seasons. Plants were multiplied in explant culture and through traditional methods – by rhizome segments (Miscanthus × giganteus) or by stem cuttings (Arundo donax). In the case of M. × giganteus, in vitro-multiplied plants produced more shoots with significantly lower diameter, but the differences in the number of shoots, plant height and the yield of dry biomass were not statistically significant. Different results were observed for A. donax, where in vitro-multiplied plants showed significantly weaker results in all parameters, with the exception of the number of shoots in the first measured season. In both the species, there was observed the strong effect of the year. While in M. × giganteus the yield of dry biomass gradually decreased during the measured years, it increased in the case of giant reed.