Effect of storage conditions on viability of wind-dispersed seeds of some cabinet timber species from Australian tropical rainforests

Summary

The poor long term viability of wind dispersed seeds of valuable cabinet timber species from Australia's North Queenslands tropical rainforests limits their utilisation in normal tree nursery operations. This study was undertaken to determine if the longevity of the seeds could be improved by manipulation of storage temperature and moisture conditions. The species tested were Flindersia bourjotiana (F.Muell.), F. brayleyana (F.Muell.), F. ijflaiana (F.Muell.), F. laevicarpa (C.T.White & Francis), F. pimenteliana (F.Muell.), Toona ciliata (M. Roemer), Agathis robusta (C.Moore ex F. Muell.) Bailey and Cardwellia sublimis (F.Muell.).

Nine treatments were applied. These involved storage in moist peat, oven-dried peat and as loose seeds under three temperatures: deep freeze (-5 to -10°C), refrigerator (5 to 10°C) and in an air-conditioned room (20–25°C). C. sublimis did not germinate after six weeks storage under any of these conditions. Moist storage destroyed the seed germinability of all other species within six weeks. Storing loose was superior to oven dry peat. Seeds stored under air-conditioning lost germinability rapidly. Freezing was superior to refrigeration but both preserved >50% of the original germinability for at least a year and in some cases for four years.