Breaking seed dormancy in Searsia pentaphylla (Anacardiaceae)

Seeds (true seed plus endocarp) of Searsia pentaphylla, a species with significant medicinal, ecological and horticultural importance, have an extremely hard and water impermeable endocarp. Hence, effective dormancy- breaking techniques are crucial for enhancing its cultivation and ensuring successful establishment in both natural and managed environments. This study evaluated the effects of mechanical scarification, chemical scarification (sulphuric acid soaking for 30, 60, 90 and 120 minutes, hydrogen peroxide soaking for 10 minutes), hot water soaking for 10 minutes, and heat treatment for three minutes at 200 degrees C on final germination percentage (FGP), mean germination time (MGT), time to 50% germination (T50), coefficient of velocity of germination (CVG) and mean daily germination (MDG). Compared to the control group (untreated seeds), the most effective treatment was 120 minutes of sulphuric acid soaking, achieving a FGP of 92%, a MGT of 7.28 days, a CVG of 13.7%, a T50 of 6.67 days and a MDG of 6.57%. Mechanical scarification yielded a FGP of 36.5%, with poorer MGT, CVG, T50 and MDG values. Other methods, including hydrogen peroxide and heat, were less effective. These results highlight the importance of aggressive scarification techniques to enhance germination in S. pentaphylla.