Adventitious rooting of mature Cycas micronesica K.D. Hill (Cycadales: Cycadaceae) tree stems reveals moderate success for salvage of an endangered cycad

Abstract

Mature Cycas micronesica trees were among the forest trees that were destined to be removed from a 2012 construction site in northern Guam.  Forty-nine of these trees were cut at the base and transported to nursery conditions to determine if adventitious root development could be stimulated as a means of saving the trees.  Fungicide and auxin were applied to the base of each stem, and perlite was used as the container medium.  A nursery maintained by an experienced cycad horticulturist yielded 41% survival, but half of the rooted plants exhibited severe stem dieback.  A nursery maintained by general plant nursery specialists without cycad experience resulted in 100% mortality.  If numerous caveats are acknowledged, whole-tree stem cuttings may yield moderate success for saving C. micronesica trees from construction sites when adequate resources are appropriated to support the nursery phase with experienced cycad biologists.