Gemination of seeds from two leguminous trees (Acacia karroo and Gleditsia triacanthos) following different pre-treatments

A lot of forest species are abandoned because of difficulty with seed germination and establishment. A study was carried out to investigate the effects of wet scarification on seed germination of Acacia karroo and Gleditsia triacanthos, by considering germination percentage (GP), mean germination time (MGT) and germination rate index (GRI). Pre-sowing treatments included immersion in concentrated sulphuric acid for 30, 60 and 90 minutes, and immersion in hot water (100 degrees C) for 5, 10 and 15 minutes. Soaking in distilled water (control) did not stimulate germination in either of the species. Treatments significantly (P < 0.001) affected GP, MGT and GM in both species. Increasing the duration of soaking in sulphuric acid (from 30 to 90 minutes) improved the germination for G triacanthos to 96%. High germination (99%) was attained for A. karroo seeds after soaking in sulphuric acid for 30 minutes.