(81) Effect of Ethephon on Establishment of Herbaceous Ornamentals in a Landscape—Response of Plants During Production Phase

Abstract

Use of growth regulators in ornamental plant production is a common nursery practice. Research conducted in determining landscape establishment of herbaceous plants treated with various concentrations of growth regulators is limited. The first phase of this study was conducted to evaluate response of three herbaceous ornamental species to application of ethephon. Containerized plants of irish moss, scotch moss, and salvia were treated once with FLOREL® (ethephon) at 0, 250, 500, or 750 ppm 2 weeks after transplanting into #1 size containers. During the course of the 6-week production period, standard nursery practices of fertigation, pest control, and weed management were followed. Data were collected on growth indices and marketable quality ratings (scale of 1–5) every 2 weeks. Mean initial and final shoot and root dry weights were calculated at the start and end of this phase of the experiment. The experimental design was completely randomized and data analyses were made using the analysis of variance with SAS general linear model procedure. Growth indices (cm) were significantly affected by increasing concentrations of FLOREL®. At 750 ppm concentration the mean growth indices were low (2516 cm) whereas, control (0 ppm) produced the highest mean growth indices (4317 cm). Significant differences in marketable quality ratings were also observed among the treatments where control (0 ppm) plants had the best mean rating (4.3) as compared with 500 ppm (3.6) or 750 ppm (3.5) concentrations. Salvia produced mean growth indices and mean width of 9106 and 513 cm, respectively. However, irish moss had asignificantly higher mean quality rating (4.4) when compared with either salvia (3.7) or scotch moss (3.3).