Abstract

During nursery production of landscape trees and shrubs it is desirable to promote the development of well-branched plants to achieve a uniform, full appearance. Branching may be promoted with multiple prunings but this is labor-intensive and expensive. In this study, spray applications of the bioregulator, cyclanilide (CYC), were evaluated for promotion of lateral branching on several container-grown landscape species. CYC spray concentrations of 0, 54, 106, and 212 ppm resulted in a linear increase in new lateral shoots for ‘Muskogee’ crape myrtle, ‘Pinkie’ and Eleanor Taber™ Indian hawthorn, and ‘Girard Rose’ azalea, and a quadratic increase in lateral shoots for ‘Compacta’ inkberry holly. Treatments to crape myrtle also caused a delay in flowering. CYC applications to Fraser photinia caused phytotoxic symptoms of leaf yellowing, blotching and curling, and increased susceptibility to entomosporium leaf spot.