Abstract:
This study was conducted to evaluate the effect of four concentrations of potassium (K; 1.3, 3.3, 5.3 and
7.3 mmol L−1) and two potting-bag sizes (5 and 10 L) on foliar biomass and related attributes and oil composition of
rose geranium (Pelargonium graveolens). Plants were grown in a climate-controlled greenhouse at the University
of the Free State and treatments were arranged in a split plot design. Potassium concentrations were allocated to
the main plots and potting-bag size to the subplots replicated three times. Plant height, K tissue content, linalool,
geraniol, geranyl formate and citronellol:geraniol ratio were affected by the K application. Plant height, number of
branches, branch:height ratio, foliage fresh mass, K tissue content and oil yield were affected by the potting-bag
size. Foliar fresh mass was significantly increased by the interaction between K concentration and potting-bag size.
Growers may use a 5.3 mmol L−1 K concentration and a 5 L potting bag for optimum production of rose geranium
under soil-less cultivation.
