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.

Seed characteristics and the influence of scarification treatments on the germination of Pterocarpus angolensis in Botswana

“…The propagation of seedlings of many indigenous leguminous woody species in tree nurseries is negatively affected by impermeable and hard seed coats, which prevent inhibition. Consequently, various authors have proposed seed dormancy-breaking techniques to improve the germination process and raise the germination rate (Rees 1996;Teketay 1996;Nadjafi et al 2006;Tiwari et al 2018;Maiguru et al 2020;Mojeremane et al 2020;Mmulotsi et al 2020). For example, Tiwari et al (2018) According to the result of the current study, the germination percentage of nicked seeds and their counterparts immersed in sulphuric acid was statistically higher than that of the control.…”

Pre-sowing treatments for enhancing germination of Guibortia coleosperma and Amblygonocarpus andongensis seeds from Kazuma Forest Reserve, Botswana

“…However, it is expensive, dangerous, and abrasive to people and materials (Doran et al, 1983) and can only be used by trained personnel. It can pollute the environment if not properly disposed of (Mojeremane et al, 2020) and seeds can be damaged by over soaking (Nasr et al, 2013). Mechanical scarification is safer and more practical when scarifying few seeds (Mojeremane et al, 2020) but it is time consuming if large quantities of seeds are scarified (Mapongmetsem et al, 1999).…”

“…It can pollute the environment if not properly disposed of (Mojeremane et al, 2020) and seeds can be damaged by over soaking (Nasr et al, 2013). Mechanical scarification is safer and more practical when scarifying few seeds (Mojeremane et al, 2020) but it is time consuming if large quantities of seeds are scarified (Mapongmetsem et al, 1999). Currently, there is little information on the germination requirement of seeds of indigenous woody plants in Botswana.…”