Effects of scarification, gibberellic acid and dry heat treatments on the germination of Balanites aegyptiaca seeds from the Sudanian savanna in Burkina Faso

To examine whether Balanites aegyptiaca (L.) Del. seeds possess physical, physiological or combined dormancy, seeds collected from Laba and Tiogo forests in Burkina Faso were subjected to different scarification and gibberellic acid treatments. The treatments applied were concentrated sulphuric acid for three or six minutes, hot water at 70, 80 and 90°C and mechanical scarification. Three concentration of gibberellic acid: 10⁻⁵, 10⁻⁴ and 10⁻³M were exogenously applied to scarified and unscarified seeds. To investigate whether the hard endocarp is an adaptation to fire, seeds were exposed to dry heat treatments at 60, 80 and 100°C for 15, 30 and 60 minutes each. Neither scarification nor gibberellic acid treatments resulted in significantly higher germination than the control. This confirms that Balanites aegyptiaca seeds exhibit no dormancy. Dry heat at 60 and 80°C for 15 minutes improved the germination of seeds collected in Laba and Tiogo respectively. It seems that low intensity heat shock elicited germination, but the result is inconclusive to show the adaptive value of the hard endocarp to fire. Further investigation is recommended to elucidate whether smoke derived from fire triggers germination of B. aegyptiaca seeds.