Influence of disinfestation and osmotic conditioning on the germinating behavior of Australian royal palm (Archontophoenix alexandrae)seeds

Abstract

The technique of Osmotic Conditioning, which consists of partial and controlled hydration of the seeds, has obtained success with various species of seeds, increasing the germinating span and tolerance to the adverse conditions of the environment, and has also reduced the time elapsed between sowing and the emergence of the plants. Associated to ideal storage conditions, the treatment has increased the performance of the seeds of tropical wood species. Aiming at studying the germinating environment and the effect of osmotic conditioning on the germination of seeds of the Australian Royal Palm tree, two experiments were performed. The first one evaluated the effect of disinfestation of the seeds of the Australian Royal Palm tree with NaClO. The treatments applied were: 0.5% sodium hypochlorite, exposure periods of 5, 15, 30, 45, 60, 90, 120 and 240 minutes, and the fungicide Captan, as control. The treatments with NaClO did not differ in relation to the final percentage of germination and to the germination speed index, and did not differ from the treatment control. The second test evaluated solutions with the following osmotic potentials: 0.0MPa (pure water), -0.4MPa, -0.6MPa and -0.8MPa, exposed for the periods of 10 and 20 days. The final percentage of germination did not differ among the treatments. The seeds hydrated in pure water for a period of 20 days showed a germination speed index significantly superior to the other treatments, and they did not show significant differences among themselves.