Growth responses of Kentucky bluegrass (Poa pratensis L.) to trinexapac-ethyl applied in spring and autumn

Abstract

The practices with low clippings production to save time, money, or landfill space, were favored by turf managers. Understanding the responses of Kentucky bluegrass (Poa pratensis L.) to Trinexapac-ethyl (TE) would facilitate recommendations regarding its safe and effective use in Northern China. The objectives of this study are (1) to investigate the effects of TE on vertical growth, clipping yield, leaf width, and chlorophyll content of Kentucky bluegrass, and (2) to compare the seasonal application impacts of TE. Both spring and autumn experiment results demonstrated that Trinexapac-ethyl applied to Kentucky bluegrass, suppressed the vertical grass growth and significantly reduced the Kentucky bluegrass clippings production within a few weeks after initial treatment. Applied trinexapac-ethyl enhanced Kentucky bluegrass leaf width in both spring and autumn experimental periods. Discoloration on leaf tips was observed and lasted for four weeks when the same TE rate of 0.191 mL$m -2 was applied in early autumn. Darker leaves with higher chlorophyll content compared with non-TE-treatments appeared after the initial four weeks of the treatment in autumn and the treatment for the entire spring.

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

“…Reductions in canopy heights as a result of TE applications were expected because these effects have been detailed in previous reports. Coolseason grass growth reduction by TE has shown by previous researchers (Ervin and Koski, 2001;Fan et al, 2009;Heckman et al, 2005), which are in agreement with the results of this study. The mode of action for TE involves accumulation at the intercalary meristems region, subsequent interference with GA biosynthesis, and reducing cell elongation in leaves (Kaufmann, 1986).…”

“…Furthermore, TE treated plants are mainly associated with shorter internode distances and lower vertical growth as compared to control plants. Fan et al (2009) reported that TE applications in spring and autumn decreased turfgrass growth and reduced mowing frequency. Results from this experiment demonstrated the benefits of sequential applications of TE for inhibition of perennial ryegrass growth.…”

“…Jeffrey and Branham (2007) reported that Kentucky bluegrass treated with TE and paclobutrazol (PAC) resulted in decreased leaf area early during inhibition followed by an increased rate of leaf area compared to controls and plant leaf area was increased by 13 or 25 percent of the control for TE-or PAC-treated plants, respectively. Fan et al (2009) reported that TE application enhanced Kentucky bluegrass (Poa pratensis L.) leaf width in both spring and autumn experimental periods. They also showed that the wider leaf turfgrass made the turf look denser and stronger than the control treatments.…”

Physiological Responses of Two Cool-season Grass Species to Trinexapac-ethyl under Traffic Stress

“…Oxidative damage has been proposed to reduce the chlorophyll content (Han et al, 2008), such that accumulation of free radicals during stress may be responsible for the loss of chlorophyll content (Inze and Montagu, 2002). Several investigators have demonstrated that TE treatment increases the chlorophyll content (Ervin and Koski, 2001;Fan et al, 2009). TE has been documented to reduce cell elongation by inhibiting gibberellin synthesis and increase the number of mesophyll cells, cytokinin content, and subsequently the chlorophyll concentration in leaves (Fan et al, 2009).…”

“…Several investigators have demonstrated that TE treatment increases the chlorophyll content (Ervin and Koski, 2001;Fan et al, 2009). TE has been documented to reduce cell elongation by inhibiting gibberellin synthesis and increase the number of mesophyll cells, cytokinin content, and subsequently the chlorophyll concentration in leaves (Fan et al, 2009).…”