2018 ASHS Annual Conference

Abelia is a woody shrub with outstanding landscape characteristics including rapid growth, adaptation to different types of soils, long flowering period, and disease, pest, and drought tolerance. Abelia has a wide variety of flower, sepal, and foliage colors. Despite the diversity of the genus, only a few species and cultivars are available commercially and these are mostly sports of Abelia xgrandiflora. Abelia has always been described as an easy to propagate plant by cuttings, but low propagation rates from cuttings has been reported from growers in A. ‘Raspberry Profusion’, a hybrid of A. ‘Edward Goucher’ x A. chinensis.

Three-node cuttings – with either two leaves per node or three leaves per nodes – were rooted in Fafard® 3B mix and dipped in 1000 or 3000 mg∙L^-1 powder Indole-3-butyric acid (IBA). Cuttings were placed under mist and evaluated after three weeks. Effect of leaf number, IBA concentration and the interaction between leaf number and IBA concentration were significant for root number and root length. The highest rooting percentage (100%), root number (37.3) and root length (8.7 mm) were obtained with 3000 mg∙L^-1 IBA on cuttings with three leaves per node.

The effect of leaf number per node was also evaluated on one-node and three-node cuttings dipped in 3000 mg∙L^-1 IBA. Leaf number per node and number of nodes per cutting significantly affected root number (p-values <0.001 and 0.020 respectively) and root length (p-values 0.013 and 0.026 respectively), but no interaction between number of leaves per node and number of nodes per cutting was observed. Root number was higher on three-nodes cuttings (28.2) and in three leaves per node cuttings (31.9). Root length was higher in one-node cuttings (10.3 mm) and in 3 leaves per node cuttings (10.5 mm), but one-node cuttings produced no shoots.