Propagation of Sweetgale, Rhodora, and Catberry by Stem Cuttings

Abstract

<jats:p>Sweetgale (<jats:italic>Myrica gale</jats:italic>), rhodora (<jats:italic>Rhododendron canadense</jats:italic>), and catberry (<jats:italic>Ilex mucronata</jats:italic>) are shrubs of eastern North America that may have potential for broader use in horticultural landscapes. Because information on their vegetative propagation is scarce, we conducted experiments over 2 years to evaluate the effects of cutting collection date, wounding, substrate composition, and the concentration of applied potassium salt of indole-3-butyric acid (K-IBA) on rooting of each species. In 2015, we collected cuttings of each species on three dates to obtain both softwood and semihardwood cuttings. Cuttings were unwounded or wounded with a razor blade, and treated by dipping into water containing K-IBA at concentrations ranging from 0 to 15,000 mg·L<jats:sup>−1</jats:sup>, after which they were inserted into a substrate of 3:1 perlite:peat (by volume) and placed under intermittent mist. In 2016, semihardwood cuttings of each species were all wounded, treated with K-IBA from 0 to 15,000 mg·L<jats:sup>−1</jats:sup>, and inserted into substrates of 100%, 75%, or 50% perlite, with the remaining volume occupied by peat. In both years, the greatest percentage of sweetgale cuttings rooted when no K-IBA was applied. K-IBA application also reduced root ratings, root dry weights, and root lengths of sweetgale. For rhodora and catberry, maximal responses for all measures of rooting occurred when 5000 to 15,000 mg·L<jats:sup>−1</jats:sup> K-IBA was applied. We recommend that growers use no exogenous auxin to propagate sweetgale, and 5000 to 10,000 mg·L<jats:sup>−1</jats:sup> K-IBA to propagate rhodora and catberry. Cuttings of all three species can be collected from softwood or semihardwood shoots. Finally, sweetgale can be rooted in perlite alone, whereas rhodora and catberry required the addition of peatmoss for satisfactory root development.</jats:p>

Evaluación del efecto rizogénico de productos orgánicos en dos tipos de sustrato en esquejes de hortensias (Hydrangea macrophylla)

“…Esta investigación muestra que la mezcla de sustrato peat-moss y agrolita puede ser usado exitosamente para enraizar esquejes de H. macrophylla, lo cual también ha sido reportado para otras especies. Peterson et al (2019) concluyeron que el uso de peat-moss en la producción de esquejes de plantas semileñosas, después de 120 días de establecidas, produjeron plantas completas, con buenas raíces y entre tres y seis brotes basales. Por otra parte Moreno et al ( 2009) evaluaron la propagación asexual de Uchuva (Physalis peruviana L.) en diferentes sustratos y encontraron que peat-moss, permitió mayor porcentaje de enraizamiento y producción de hojas, como consecuencia de una buena formación de raíces.…”

Effects of seasons and indole-3-buteric acid doses on the propagation of some native rhododendron species by air layering technique in their natural habitats

“…Ferus et al (2017) reported that the rooting efficiencies of cuttings ranged between 0% and 100% in their study with eight Rhododendron species. Peterson et al (2020) conducted a study on the propagation of sweetgale, rhodora, and catberry species by cuttings. They found that the K-IBA concentration and wounding treatments in Rhodora (Rhododendron canadense (L.) Torr.)…”