Axillary Shoot Growth, Rooting and Overwinter Survival in Stem Cuttings of Viburnum dentatum ‘Chicago Luster’

Abstract

Abstract The effects of stock plant and cutting manipulation on propagation success of Viburnum dentatum ‘Chicago Luster’ were studied. One-node semi-hardwood stem cuttings were harvested from greenhouse-grown stock plants. Cuttings from plants decapitated 21 days before harvest (compared to non-decapitated plants), and one-leaf (compared to two-leaf) cuttings, had relatively high rooting potential and a high initial percentage of axillary shoot flushing. However, subsequent shoot growth, and overwinter survival, were less. A second stock plant decapitation resulted in the flushing and initial growth of all axillary shoots by the time cuttings were stuck. These cuttings all survived the propagation phase and soon resumed shoot growth, even after transplanting, and the plants all survived the following winter. In cuttings with actively growing axillary shoots, shoot extension growth was greatest in cuttings reduced at sticking to one leaf and one shoot in the leafless axil, but the radial distribution of roots was not uniform, being concentrated in the same 180° sector of the stem as the shoot. Incorporating controlled-release fertilizer (CRF) in the rooting substrate during the propagation phase tended to reduce initial survival but promoted rooting and shoot growth among the survivors, even after transplanting and increased overwinter survival.