Abstract

Single applications of 0 to 200 ppm cyclanilide (CYC), an experimental bioregulator effective in stimulating lateral branching in fruit trees, were applied to the foliage of 19 species or cultivars of woody landscape shrubs over the 2004 and 2005 seasons, 12 of which exhibited increased branching in response to treatment. New shoot increases were concentration and species dependent. Compared to untreated controls at 30 days after treatment (DAT) in 2004, new shoots increased from 14 to 317% across Florida anise, ‘Elizabeth Ann’ Japanese camellia, ‘Nigra’ inkberry holly, ‘Chinsan’ azalea, ‘Red Slippers’ azalea, ‘Watchet’ azalea, ‘Ellen Huff’ oakleaf hydrangea, ‘Brandy's Temper’ sasanqua camellia, and Eleanor Taber™ Indian hawthorn following CYC application. In 2005, shoot increases at 60 DAT ranged from 32 to 240% across ‘Ellen Huff’ oakleaf hydrangea, ‘Brandy's Temper’ sasanqua camellia, Eleanor Taber™ Indian hawthorn, Olivia™ Indian hawthorn, ‘Sky Pencil’ holly, and ‘Foster’ holly. Plant size decreased, increased, or was unaffected by increasing CYC concentration. Foliage of ‘Ellen Huff’ oakleaf hydrangea in 2004 and Eleanor Taber™ and Olivia™ Indian hawthorn in 2005 was injured by CYC application, however symptoms were no longer evident by the end of the growing season. Quality of treated responsive plants at the end of the growing season in 2004, but not in 2005, was usually higher than that of untreated plants and generally increased with increasing CYC concentration.