Longevity of buried ragwort seed in four soils

Abstract

The viability of ragwort (Senecio jacobaea L) seed buried for several years at 0 2 4 6 and 19 21 cm depths was evaluated in four different soil types Seed samples in nylon mesh bags were removed after 1 2 3 5 11 and 16 years burial and their viability determined by germination After 16 years no viable seed was found in the clay soil In the silt loam and peat soils 1 3 viable seed remained while in the sandy soil up to 13 remained viable In the surface 0 2 cm layer of soil it took from 109 to 146 years for the percentage of viable seed to fall to 1 of the original viable seed depending on soil type At the 4 6 and 19 21 cm depths the corresponding times were 128 165 years and 130 180 years