Experimental manipulation of patterns of resource allocation in the growth cycle and reproduction of Smyrnium olusatrum L.

Plants of the monocarpic (normally biennial) Smyrnium olusatrum (Umbel]iferae) were grown in pots in soil at a high or low nutrient regime. Some plants receiving full nutrients were grown in a heated glasshouse with 16 h days. The remainder were grown without supplementary lighting or heat and included control plants and others which received surgical treatment after ten months growth: deradication (removal of half of the root stock); defoliation; deradication and defoliation. The distribution of plant biomass and of phosphorus were analyzed at the time of seed set.
Patterns of allocation of dry matter and phosphorus were quite different and were significantly altered by treatments, which produced a range of allocation to reproductive structures ranging from 21 to 74% of total phosphorus and 12 to 35% of dry matter.
Distribution patterns of total phosphorus are discussed in terms of the potential demands being made by alternative structures and functions over the life cycle of the plants.