Preliminary studies on Tephrosia species: Effect of seed treatments on germination

Abstract

Germination tests were conducted on the seeds of three species of Tephrosia (T. bracteolata, T. candida, and T. linearis) to investigate potential seedling establishment and possible pre-treatments to improve seed germination. Pre-culture treatments were: i) No treatment (control), ii) rubbed in sand paper, iii) soaking in boiled water for 30 seconds, iv) for 3 minutes, v) for 5 minutes, vi) soaking in concentrated sulphuric acid, and vii) soaking in water for 24 hours. After treatment, a total of two hundred and fifty seeds (5 replicates each of 50 seeds) were cultured on moist filter paper for 15 days. Cumulative percentage germination, percentage dormant seeds and germination rates were calculated. Seeds of all the species of Tephrosia exhibited innate dormancy at varying levels, but most pronounced in T. linearis. Soaking seeds in boiled water for 30 seconds to 5 minutes resulted in higher seed germination (p<0.05) than other pre-culture seed treatments in all the genotypes. Percentage hard seeds were also minimal in seeds treated this way, indicating effective dormancy alleviation in Tephrasia by these treatments. From the trial, soaking seeds in boiled water for 30 seconds is recommended as treatment of Tephrosia seeds to enhance germination and optimal potential seedling establishment.