A comparison of growth in two accessions of Portulacaria afra (L.) Jacq. cultured hydroponically in saline solutions

Abstract

Portulacaria afra (Spekboom) was tested for its potential as a hydroponically grown carbon-credit crop. Two accessions were grown in control and salinated (2.5 g/l) nutrient solutions. There was little statistical difference in growth parameters (number of leaves, stem height and diameter, wet and dry masses of root, stem and leaf and nett carbon assimilation) between the two accessions over the 14-week experiment, although the upright accession (KBG 408/1975) showed a root biomass higher than the prostrate accession (KBG1203/83). Its roots showed to be better suited to growth under hydroponic conditions but were more significantly impacted by the saline treatment. The number of leaves, leaf wet and dry masses, root dry mass, total wet and dry masses and therefore growth and nett carbon uptake of both acessions of P. afra were significantly reduced by the saline treatment.