Effect of mowing, rust infection and seed production upon C and N reserves and morphology of the perennial Veratrum album L. (Liliales, Melanthiaceae)

In this field study the effect of mowing, rust infection and seed production was determined on nonstructural carbohydrate (C) and Kjeldahl nitrogen (N) reserves in rhizomes, as well as on plant morphology of the perennial weed Veratrum album L. (Liliales, Melanthiaceae). Rust infection and seed production had only a minimal influence on the concentrations of C and of N during either the summer or the following winter. However, mowing one month after early shoot growth led to decreased C (-40%) and increased N (+100%) concentrations of rhizomes sampled during the following winter. In a long-term experiment, the decrease in C reserves was shown to coincide with dwarfism of V. album plants. Mowing for six consecutive years reduced total plant biomass by 50%. Accordingly, total N and C reserves per plant rhizome decrease substantially. However, seasonal patterns of C and N concentrations were not influenced by mowing, except for the differences in winter concentrations that were already observed in the Short-term experiment. Long-time mowing not only led to dwarfism of V. album plants, but also significantly decreased generative and vegetative proliferation.