2018 ASHS Annual Conference

Sean Markovic, Graduate Student and Dr. Jim Klett, Colorado State University, Department of Horticulture and Landscape Architecture

Abstract

Commercial growers throughout the Rocky Mountain Region have an increased demand for sustainable herbaceous perennial plants. Production of these adaptable perennials has resulted in problems in stock plant management and propagation. The objective of this study was to determine the efficacy of plant growth regulators applied as foliar sprays on the vegetative growth of Heuchera sanguinea ‘Snow Angel’ and Zauschneria garrettii ‘Orange Carpet’ propagation stock plants in number one containers. Three chemical plant growth regulators were applied at two different rates: 1) Ethephon [250 and 500 mg·L–1 (ppm)] (Verve, Nufarm Americas, Inc., Alsip, IL), 2) 6-benzylaminopurine (200 and 400 mg·L –1) (Configure; Fine Agrochemicals Limited, Worcester, U.K.), and 3) Gibberellins A4A7 (GA) & N-(phenylmethyl)-1H-purine 6-amine (50 and 100 mg·L–1) (Fascination; Valent USA Corp., Fresno, CS). Twelve replications of the two taxa were evaluated once for four months for plant height, width, number of branches, number of cuttings, and fresh & dry weight of the cuttings. This study was replicated twice, the first experiment was performed from November 2016 to March 2017, and the second experiment was performed from August 2017 to December 2017. The two different seasons aided in indicating a better time of year for stock production of these two herbaceous perennials. Heuchera plants that received GA treatments at 50 and 100 mg·L–1 and 6-benzylaminopurine at 400 mg·L–1 concentrations resulted in 17%, 22%, and 20% more cuttings taken than control plants. All concentrations of Ethephon treated Heuchera plants were similar to the control plants, respectively. Zauschneria plants that received GA treatments at 50 and 100 mg·L–1and 6-benzylaminopurine at 200 mg·L–1 concentrations had 14%, 16%, and 10%, respectively. Zauschneria plants that received GA treatments at 50 and 100 mg·L–1had a decrease of 13% and 14% for the fresh weight of cuttings taken when compared to the control.