Enhancing Germinatmon of four Australian Acacia Species through Seed Treatments Overcoming Coat-Imposed Dormancy

Abstract

Germination of the Acacia species A.aneura, A. farnesiana, A. saligna and A. victoriae is usually low due to impermeable seed coats causing dormancy. Propagation and distribution of the species for afforestation and reforestation projects requires higher germination and establishment rates. A number of pre-sowing seed treatments were examined with the goal of breaking seed-coat-imposed dormancy. Both concentrated sulphuric acid (H_2SO_4) and water treatments were applied to Acacia seeds in various combinations at 15,20,25 or 30°C. Results revealed that soaking seeds in concentrated H_2SO_4 or in water significantly increased germination percentage of treated seeds. Response to temperature followed a line reflecting habitat annual temperature for the four species. It is concluded that H_2SO_4, or water may be used to treat seeds of the four species to improve germination percentages.