Enhancing seed germination of Ceratonia siliqua L. for large scale production in southern Africa

F.J.L. Kruger, H.T. Araya, R. Kleynhans, C.P. du Plooy
The pods of Ceratonia siliqua L. (Fabaceae) have taken foot in the ever-growing diet industry as chocolate replacements. The demand for the production of pods has subsequently increased and the upscaling of production is required. The horticultural practices to achieve such results are not as easily achieved with the carob tree as is commonly known. This is because C. siliqua is a slow growing tree, with different genders. Only the female trees produce the pods of interest. Another obstacle to overcome is seed dormancy that is attributed to its seemingly impervious seed coat. In this study, there were four treatments: the first seeds were treated with boiling water (100°C) for 30 min, the second group was chemically scarified by sulphuric acid for 30 min, the third treatment mechanically scarified until the green endocarp was visible, and last was the untreated control group. All treatments were then subjected to a 24 h imbibition period in distilled water and incubated at 25°C, with three different photoperiods: 8 h light, 12 h light or complete darkness. The germination percentages achieved showed that mechanical scarification had the highest germination percentage (90%), followed by the sulphuric acid (36%) and boiled water (24%) treatments. Photoperiod did not affect germination. Thus, in order to propagate C. siliqua successfully, mechanical scarification of the seed is very important to ensure a high germination percentage of the seeds if the crop is to be commercialized at a large scale.
Kruger, F.J.L., Araya, H.T., Kleynhans, R. and du Plooy, C.P. (2018). Enhancing seed germination of Ceratonia siliqua L. for large scale production in southern Africa. Acta Hortic. 1204, 139-142
DOI: 10.17660/ActaHortic.2018.1204.18
carob, Ceratonia siliqua, seed germination, seed treatments

Acta Horticulturae