Two experiments were carried out at Antoniades Research Branch, Ornamental Plants Research and Landscape
Gardening Department Horticulture Research Institute, A.R.C. Alexandria, Egypt during the two successive seasons
2014/2015 and 2015/2016 to investigate the effect of sodium alginate (SA) and irradiated sodium alginate (ISA) on seed
germination and the growth of Acokanthera plants. The first experiment was to investigate the effects of (SA and ISA) on
seed germination; the seeds of Acokanthera were soaked in seven solution 50 ppm SA and different concentrations of ISA
[0.0 (distilled water), 50, 75, 100, 125 and 150 ppm] for 24 hours, The treatment 50 and 125 ppm ISA significantly
improved germination rate and percentage. The second experiment was to study the effect of the foliar spray of SA and
ISA on Acokanthera plants with the same concentrations used in the first experiment the results showed that all treatment
of ISA caused an increment in most studied characters and the treatment 50 ppm ISA caused the highest significant
increase in all vegetative growth parameters ( plant height, numbers of leaves, fresh weight ,dry weight, leave area and
stem diameter) , root characters (root volume and root dry weight), chlorophyll and carbohydrate content.