S05 - Session P2 - The influence of plant hormones on flowering and chlorophyll content of Leucadendron elimense E.Phillips subsp. Elimense

Authors: Carolyn Wilmot *, Charles Laubscher, Jenny Liedtke

Overharvesting of cut flowers and the destruction of natural habitats have forced Leucadendron elimense subsp . Elimense, an endemic, fynbos shrub from the Agulhas Plain of South Africa, to become an endangered species. Both male and female plants of this species are valued as floricultural products. Improvement of production methods could advance the sustainable and economic cultivation practices for a suitable and marketable product and further aid in the conservation of the species. The aim of the study was to determine the use of plant hormones on the flowering percentage, chlorophyll content and fresh weight of the species. Plant material was sustainably harvested from randomly selected male and female plants growing in their natural habit. Experimental treatments consisted of a once-off application of Indole-3-acetic acid (IAA), 1-Naphthaleneacetic acid (NAA) and Indole-3-butyric acid (IBA) at selected concentrations of 2000 ppm, 4000 ppm and 6000 ppm on male and female plants, respectively. Treated, terminal cuttings were planted into perforated, transparent, bags in a mix of two parts coarse river sand, one-part coco peat and one-part perlite (2:1:1). Aeration of the rooting medium was essential and irrigation misting was regulated at 500 ml per interval under semi-controlled greenhouse conditions. Results of fresh weight and chlorophyll content showed significant increases in flowering percentage of female plants using IAA at 4000 ppm, whilst NAA treatments were more successful on the male plants. The study presented that an application of plant hormones enhanced the final product quality with evidence of improving the flowering for both cut flower and potted plant production of male and female plants. New scientific advances can successfully support restoration ecology of red listed species in a declining habitat .