Effects of pre-treatments methods on the germination of pod mahogany (afzelia quanzensis)and mukusi(baikiaea plurijuga)seeds

Abstract

Seed pre-treatments (mechanical, concentrated sulphuric acid for 3, 6, 9 and 12 minutes, hot water treatments for 3, 6, 9 and 12 minutes) were carried out to overcome seed dormancy of Afzelia quanzensis and Baikiaea plurijuga seeds between January and March 2013. Completely randomized designs (CRD) with 4 main treatments (including the control) each replicated 4 times were used. Percentage germination, germination mean time (GMT) and germination index (GRI) were calculated and the data was subjected to analysis of variance (ANOVA). Mechanical scarification significantly (p<0.01) increased the germination of A. quanzensis seeds. Maximum germination percentage (100%) was observed within the shortest GMT of 2.5 days. Also, seed germination was significantly (p<0.01) increased by treating with sulphuric acid for 6 min however, more time was needed to germinate the seeds. All seed pre-treatments except for seeds soaked in sulphuric acid for 6, 9 and 12 min significantly (p<0.01) increased B. plurijuga seeds germination. Maximum germination percentage (100%) was attained with seed soaked in hot water for 9 min. However, hot water treatment revealed superior absolute numbers compared to the rest. Generally, mechanical scarification is the methodthat suits the two tree species.