Ethephon and Trinexapac-ethyl Influence Creeping Bentgrass Growth, Quality, and Putting Green Performance

Abstract

Combining ethephon with trinexapac‐ethyl effectively inhibits Poa annua L. seedheads and applying this combination during summer months may enhance growth regulation of creeping bentgrass (Agrostis palustris Huds.) relative to exclusive trinexapac‐ethyl use. To test this hypothesis, a two‐year field experiment investigated growth, quality, and ball‐roll distances of an ‘L‐93’ creeping bentgrass golf green treated with ethephon at 0, 3.8, or 7.6 kg a.i./ha with trinexapac‐ethyl at 0 or 0.04 kg a.i./ha every 4 weeks over 12 weeks. Ethephon provided substantial clipping yield reductions but did not enhance ball‐roll distances alone or improve trinexapac‐ethyl efficacy. Trinexapac‐ethyl most effectively suppressed creeping bentgrass shoot growth one to two weeks after treatments but post‐inhibition shoot growth enhancement occurred which exacerbated summer root decline. Overall, clipping reductions from ethephon do not enhance ball‐roll distances and ethephon does not appear to enhance growth regulation effects of trinexapac‐ethyl on creeping bentgrass golf greens.

A Growing Degree Day Model to Schedule Trinexapac‐ethyl Applications on Agrostis stolonifera Golf Putting Greens

“…Visual quality of the TE treatments was not statistically different from the control until 6 to 7 wk after the initial TE applications. Delayed visual quality enhancement results are consistent with findings reported by McCullough et al (2006a). Table 2.…”

“…Influence of trinexapac-ethyl application rate and reapplication frequency on magnitude and duration of growth suppression in various turfgrass species. Reference McCullough et al, 2006aMcCullough et al, 2007Stier and Rogers, 2001Tan and Qian, 2003Beasley and Branham, 2007Gardner and Wherley, 2005Gardner and Wherley, 2005McCarty et al, 2004Stier and Rogers, 2001Richie et al, 2001Gardner and Wherley, 2005McCullough et al, 2007Fagerness and Yelverton, 2000Fagerness et al, 2004Qian and Engelke, 1999 ' Duration dependent on summer or fall season.…”

Effects of Sequential Trinexapac-Ethyl Applications and Traffic on Growth of Perennial Ryegrass (Lolium perenne L.)

“…2). Inhibition of leaf expansion has been shown to increase mesophyll cell density and chlorophyll concentration, resulting in dwarfed shoots that enhanced turfgrass color and quality (Ervin and Koski, 2001;Heckman et al, 2005;McCullough et al, 2006a). …”

“…Enhanced turf quality following TE applications is most likely a function of enhanced color and tiller density. McCullough et al (2006a) reported that repeated TE applications typically enhanced turf color, quality, and tiller density four to eight weeks after initial TE application.…”

“…A number of researchers have reported that TE reduced turfgrasses shoot growth, mowing requirement, and enhanced turf quality (Burpee et al, 1996;Daniels and Sugden, 1996;Ervin and Koski, 1998;McCullough et al, 2006a;McCullough, 2004). McCullough et al (2006b) reported that applications of TE decreased clipping yield of 'TifEagle' bermudagrass (Cynodon dactylon L.).…”