Germination studies on seeds of Burkea africana and Erythrophleum africanum from Kazuma Forest Reserve, Northern Botswana

Abstract

Burkea africana and Erythrophleum africanum are characterized by seed coat-imposed dormancy that prevents water entry and gaseous exchange, which are essential for the germination process. The objective of this study was to determine the best possible pre-sowing treatment method that maximizes seed germination of the two species. Seeds of both species were subjected to four experiments, containing 10 levels of presowing treatments: The control, mechanical scarification, soaking in concentrated sulphuric acid (for 15, 30, 45 and 60 min), immersion in boiling water (for 1, 3 and 5 min), and soaking in boiling water (and cooling down for 24 h). The germination data were subjected to ANOVA followed by Tukey’s HSD Test to separate significantly different treatment means. The most promising results showed that seeds treated with mechanical, sulphuric acid and boiling water scarification had significantly higher mean percent germination than the controls for B. africana; whereas for E. africanum, mechanical scarification, exposure to sulphuric acid, boiling water (1 min) and immersion in boiling water (and cooling down for 24 h) had higher percent germination than the controls.   Key words: Burkea africana, Erythrophleum africanum, germination percentage, pre-sowing treatment, seed dormancy.