Abstract

Softwood shoot cuttings of Acer griseum, A. rubrum ‘Bowhall’, A. rubrum ‘Franksred’ Red Sunset^™, A. saccharum ‘Legacy’, Cornus kousa, Quercus alba, Q. ellipsoidalis, and Q. palustris were subjected to hormone treatments (IBA and control) and placed in a fog-humidified polyethylene tent rooting chamber under one of three levels of shade (83% or control, 91%, and 97% of ambient sun). Percentage rooting, the number of roots per cutting, and the number of days to root were significantly influenced by shade levels and hormone treatment, but responses were dependent on species or cultivar. For most taxa, percentage rooting was greatest at 91% or 97% shade. Only for A. griseum was the control shading treatment best for rooting. Generally, under the greater shade levels, the IBA treated cuttings rooted more often, had more roots, and rooted faster than cuttings without IBA. However, in some cases, the hormone treatment did not provide a clear advantage. Results of this study demonstrate that high shade levels in the rooting environment can increase the rooting performance of cuttings of a number of woody plant taxa.