The 2011 ASHS Annual Conference

Perlite is a common material used for propagation of ornamental nursery crops throughout the United States. However with increasing material costs and health concerns (due to inhalation of fine dust into the lungs) many growers are looking for alternatives. Eastern redcedar (Juniperus virginiana) is a common, aggressive tree species in the Great Plains region of the United States. Previous research with the production of ornamental nursery crops in eastern redcedar substrate has shown the species to have good potential as an alternative substrate. The objective of this study was to evaluate eastern redcedar as a substrate replacement for perlite in vegetative plant propagation. Plants in this study included Chrysanthemum (Chrysanthemum x morifolium 'Abelle') and Ivy Germanium (Pelargonium peltatum 'GerIV Colorcade Cherry Red'). Chyrsanthemum cuttings were treated with 1500 ppm indole-3-butyric acid, potassium salt (IBA-K) and all cuttings were grown in a greenhouse under overhead mist, which provided water every 10 minutes for 15 seconds, and supplemental lighting, which provided 16 h day length. Five substrates consisting of perlite or redcedar that had been processed through a hammer mill to pass a 0.48 cm screen were evaluated. These materials were blended to create a substrate containing either 1 100% perlite, 2) 25% redcedar: 75% perlite, 3) 50% redcedar: 50% perlite, 4) 75% redcedar: 25% perlite or 5) 100% redcedar. No mix contained fertilizer and the experiment lasted 26 days for Chrysanthemum and 33 days for Ivy Geraniums. Results showed that root and shoot dry weight, root surface area and root volume were statistically similar for all substrates in both species. However, root length generally decreased while root diameter increased in redcedar content increased. Plants grown in redcedar had shorter, wider roots and plants grown in perlite had longer, finer roots. Despite this difference, both plants species were successfully propagated demonstrating that Eastern Redcedar can be used as a propagation substrate for both Ivy Geranium and Chrysanthemum.