| Scope and method of study. The purpose of this study was to address the hypothesis that Caddo sugar maples can be successfully propagated by cuttings. I developed two research questions to help address the hypothesis. First, can the accumulation of heat degree-day units and the characterization of morphological markers be used to predict the ideal timing to take softwood stem cuttings from adult Caddo sugar maple trees? Second, would mound layering hasten rooting of softwood cuttings? I also wished to identify superior sugar maples that respond well to cutting propagation so clones can be developed. I also desired to increase the scientific body of knowledge about sugar maple adventitious root formation by characterizing the anatomy of root formation in stem cuttings.; Findings and conclusions. Caddo sugar maples can be successfully propagated by stem cuttings when cuttings are taken upon the accumulation of around 1600 to 2200 degree days, which coincides with the early shoot expansion or green softwood stages, and treated with at least 5 g · L−1 indolebutyric acid. Tree source for cuttings did affect rooting and we recommend four specific trees on the campus of Oklahoma, State University, Stillwater, Okla. as potential parents to a cultivar because of their desirable ornamental characteristics, stress resistance and rootability. Mound layering of seedlings did not prove a successful method for propagation in our study. We found that root initiation in Caddo sugar maple stem cuttings occurred in two areas: in new cell growth in the cortex near a leaf trace and near the original cambium. |
