Abstract
Grassland restoration requires knowledge of seed storage to maximise or maintain seed germination power (PG) at sowing. In this work we evaluated the changes in PG and the need for post-maturation under different conditions and storage times. Germination of Bromus catharticus, Jarava plumosa, Nassella longiglumis, N. neesiana, Piptochaetium napostaense and Poa ligularis was evaluated at different times from harvest (freshly harvested, three, six or fifteen months from harvest) and different storages (three at constant temperature —freezer at-18°C [F], refrigerator at 4°C [H] and culture room at 20°C [S]— and two under variable temperature —indoor room temperature [~15-25°C] [A] and outdoor room temperature [~5-45°C] [G]). Four species increased their PG after harvest compared to freshly harvested, while the remaining species maintained a PG similar to that at harvest, and elevated (>75%). In general, storage at-18°C and 4°C reduced the PG compared to the other treatments. In some species the PG increased over time (P. napostanese and P. ligularis) and in others it decreased (B. catharticus) while in the others it remained unchanged. The low germination immediately after harvest and its subsequent increase suggests that most species require a period of post-maturation after harvest, except for J. plumosa and N. longiglumis. In addition, the method of storage will affect the subsequent PG, which is crucial to define the viability of each species in restoration projects, especially in areas such as southwestern Buenos Aires, where climatic variations are considerable and often limiting.