Response of ‘Captiva’ St. Augustinegrass to Shade and Potassium

Abstract

<jats:p>The effects of potassium (K) on stress tolerance of turfgrass have been documented for some environmental stresses but not for shade tolerance. ‘Captiva’ st. augustinegrass [<jats:italic>Stenotaphrum secundatum</jats:italic> (Walt.) Kuntze] was evaluated in this research project to determine the effects of K and shade on turf performance. The study was conducted at the University of Florida Envirotron Turfgrass Research Laboratory in Gainesville, FL. Grasses were planted in 15.2-cm plastic pots in a climate-controlled glass house. Two consecutive studies were conducted, the first from 20 May to 24 Oct. 2009 and the second from 18 Jan. to 20 June 2010. Grasses were placed in either full sun or under shade structures covered with woven black shadecloth to provide 30%, 50%, or 70% shade. Potassium was applied as potassium chloride (KCl) (0–0–62) at four rates (0, 0.6, 1.2, or 2.4 g·m<jats:sup>−2</jats:sup>) every 30 days. In both trials, turf visual quality and color scores and dry weight (DW) of shoot and root were lowest at 70% shade and highest at 30% shade. Turf visual quality score increased as K rate increased. Leaf length increased and leaf width decreased as shade level increased. Leaf tissue total Kjedahl nitrogen (TKN) and K concentration increased as shade level increased from 0% to 70%. Thatch DW was greatest at 70% shade and lowest at 30% shade. In the first trial, turf treated with a higher K rate had longer leaf length and greater root DW. Results from this study showed that ‘Captiva’ could maintain acceptable visual quality at up to 50% shade and that K at 2.4 g·m<jats:sup>−2</jats:sup> may help turfgrass grow in a shaded environment by improving turf visual quality score, root growth, and leaf tissue K concentration. Additional field plot research should be conducted to verify these responses.</jats:p>

Performance of diploid and interploid hybrids of St. Augustinegrass under moderate shade

“…Researchers have studied St. Augustinegrass under filtered tree shade (Almodares, 1980; Barrios et al., 1986), structured shade (Cai et, al.,2011; Busey, 2010), as well as controlled environment conditions in greenhouses (Trenholm & Nagata, 2005; Wherley et al., 2013; Zhang et al., 2017). Although controlled environment experiments allow researchers to specifically and more rapidly evaluate the response of plants under shade, it does not account for plant exposure to confounding environmental conditions and management practices such as temperature extremes, disease pressure, mowing heights, and frequency encountered in the field that could influence their overall performance under shade.…”

Isolation and Characterization of Microsatellite Markers for Stenotaphrum Trin. Using 454 Sequencing Technology

“…These species grow on 0 to 1100 m altitudes and are naturally distributed in south China (Chen and Phillips, 2006;Liu, 2010). St. augustinegrass has rich genetic variation Mulkey et al, 2014); however, studies on the genetic diversity of St. Augustinegrass are limited (Busey, 1995(Busey, , 2003Cai et al, 2011;Cathey et al, 2011;Kimball et al, 2012;Milla-Lewis et al, 2013;Mulkey et al, 2014). Mulkey et al (2013Mulkey et al ( , 2014 developed simple sequence repeat markers of S. secundatum and identified 30,895 contigs containing simple sequence repeat (SSR) markers.…”