Temporal Shade on Creeping Bentgrass Turf

Abstract

Creeping bentgrass (Agrostis palustris Huds.) turf exposed to shade during morning hours may decline more readily than similar turf exposed to afternoon shade. This study compared the quality and physiological responses of creeping bentgrass turf exposed to morning shade with turf exposed to afternoon shade and evaluated responses of the same species exposed to varying shade densities during the same period. Semipermanent shade structures were placed on a creeping bentgrass range maintained at a 6.4-mm height. Structures provided 6 h of morning shade or 6 h of afternoon shade during the summer solstice. Each structure was covered with either 80 or 100% shade cloth and replicated three times. Control treatments of full sun and perpetual shade were also included. Treated turf was evaluated monthly for color, density, root mass, pigment concentrations, and total nonstructurai carbohydrates (TNC). Regardless of response tested, no significant variation was found between plots receiving morning shade and afternoon shade or between plots in 80 and 100% shade. Canopy temperature, in comparison with air temperature, was 7% greater in morning shade than in afternoon shade, but the relationship between canopy temperatures in full sun and shade did not change during the day. Perpetual shade caused a 38% decrease in color and a 33% decline in density but treatments receiving 6 h of shade did not vary from the full sun treatment. Concentrations of chlorophyll a (46%) and b (50%), neoxanthin (31%), violaxanthin (44%), lutein (34%) declined in perpetual shade compared with full sun. Violaxanthin concentration was influenced by photosynthetic photon flux, suggesting its potential use as a shade stress indicator. S HADE is considered detrimental to turfgrass growth and development. Reduced levels of photosynthetic irradiance result in thinner, more delicate leaf blades (Dudeck and Peacock, 1992) prone to mechanical injury and disease infection. Under shaded conditions, carbohydrate availability is limited due to decreased photosynthetic production and results in reduced stem and root growth, reduced tillering, and poor shoot density. Trees, smaller plants, and structures providing shade also reduce air circulation and increase relative humidity, causing leaf surfaces to remain wet with dew for many hours. These wet leaf surfaces combined with reduced evapotranspiration create a microclimate conducive to disease development. Physiological turfgrass features such as pigment concentrations (Possingham, 1980; Wilkinson and Beard, 1975) and carbohydrate reserve (Voskresenskaya, 1972; Burton et al., 1959) may be affected by shade stress. A reduction in the ratio of

Impacts of Altered Light Spectral Quality on Warm Season Turfgrass Growth under Greenhouse Conditions

“…In nature, trees alter spectral quality available for turfgrass development (Bell et al, 2000); however, limited research has investigated the light specific tree species filter in highly maintained turfgrass environments. Also, most turfgrass shade research has focused on light quantity using black neutral shade material (Bell and Danneberger, 1999; Koh et al, 2003; Steinke and Stier, 2003; Bunnell et al, 2005a; Baldwin et al, 2008).…”

Nitrogen Rate and Mowing Height Effects on TifEagle Bermudagrass Establishment

“…Putting green management research has typically focused on the two major species for putting greens: (i) hybrid bermudagrass (Brown et al, 1977; Goatley et al, 1994; Snyder and Cisar, 2000; Hollingsworth et al, 2005) or, (ii) creeping bentgrass ( Agrostris palustris Huds.) (Salaiz et al, 1995; Bell and Danneberger, 1999; McCarty et al, 2005). These researchers evaluated treatment responses on established greens, and not during the establishment period, when management practices might differ from those used on an established green.…”

Comparison of Acetone and N,N-Dimethylformamide for Pigment Extraction in Turfgrass

“…After the initial 20 min of stirring, the extracts treated with DMF were noticeably darker green and had less green tissue remaining than extracts with acetone. Bell and Danneberger [12] were unable to elucidate this pigment in creeping bentgrass using simple 80% acetone extraction and the same HPLC procedure. This visual observation was supported by HPLC area unit results ( Table 2).…”

“…[16][17][18] Those studies used extinction coefficients and formulas obtained from work by Moran, [14] or more recently by Inskeep and Bloom [15] for pigment quantification. Bell and Danneberger [12] used acetone extraction and HPLC to simultaneously assess chlorophylls and carotenoids, including xanthophylls, of creeping bentgrass grown in shade and full sun. [1] In a study testing chlorophyll content of turfgrasses following application of plant growth regulators, Gaussoin et al [19] used DMF for extraction to prepare for spectrophotometric pigment analysis.…”