@article{wherley_sinclair_dukes_schreffler_2011, title={Nitrogen and Cutting Height Influence Root Development during Warm-Season Turfgrass Sod Establishment}, volume={103}, ISSN={["0002-1962"]}, DOI={10.2134/agronj2011.0146}, abstractNote={Effective water conservation in the landscape requires identification of cultural management practices that maximize the genetic rooting potential of establishing turfgrass sod. Nitrogen is critical for successful turfgrass establishment; however, there has recently been debate over whether to restrict N fertilization during summer periods in parts of Florida and the United States. This study was undertaken to examine within four warm‐season turfgrass species, the relative influences of cutting height and N fertility on the (i) rate of root extension and (ii) root biomass produced over a 10‐wk period. ‘Tifway 419’ bermudagrass (Cynodon dactylon (L.) Pers. × C. transvaalensis Burtt Davy), ‘Empire’ zoysiagrass (Zoysia japonica Steud.), ‘Argentine’ bahiagrass (Paspalum notatum Flugge), and ‘Floratam’ St. Augustinegrass (Stenotaphrum secundatum Walt. Kuntze) were established from 10‐cm diam. by 5‐cm deep plugs of turfgrass sod into 90‐cm tall, clear acrylic tubes. Experimental treatments were arranged in a complete factorial that was repeated over two growing seasons. Rates of root extension were calculated from weekly measures of the deepest visible root in each column. Root extension rates ranged from ∼1.0 to 1.8 cm d−1 during the studies, with bahiagrass exhibiting the most rapid root extension of the four species. The results demonstrated that increasing N fertility during establishment increased rates of root extension into deep soil, particularly in bermudagrass. Height of cut had no effect on rate of root extension for most species, but higher cutting height did promote more rapid root extension in bermudagrass. Although not significantly accelerating vertical root extension in most species, maintaining sod at the higher cutting heights resulted in significantly greater root proliferation within both upper and lower soil depths for all species. The results emphasize the importance of proper N fertility and cutting heights for optimizing root development of different turfgrass species during sod establishment.}, number={6}, journal={AGRONOMY JOURNAL}, author={Wherley, B. G. and Sinclair, T. R. and Dukes, M. D. and Schreffler, A. K.}, year={2011}, pages={1629–1634} }
 @article{sinclair_fiscus_wherley_durham_rufty_2007, title={Atmospheric vapor pressure deficit is critical in predicting growth response of “cool-season” grass Festuca arundinacea to temperature change}, volume={227}, ISSN={0032-0935 1432-2048}, url={http://dx.doi.org/10.1007/s00425-007-0645-5}, DOI={10.1007/s00425-007-0645-5}, abstractNote={There is a lack of information on plant response to multifactor environmental variability including the interactive response to temperature and atmospheric humidity. These two factors are almost always confounded because saturated vapor pressure increases exponentially with temperature, and vapor pressure deficit (VPD) could have a large impact on plant growth. In this study using climate controlled mini-greenhouses, we examined the interacting influence of temperature and VPD on long-term growth of tall fescue (Festuca arundinacea Schreb), a cool season grass. From past studies it was expected that growth of tall fescue would decline with warmer temperatures over the range of 18.5-27 degrees C, but growth actually increased markedly with increasing temperature when VPD was held constant. In contrast, growth declined in experiments where tall fescue was exposed to increasing VPD and temperature was held constant at 21 degrees C. The inhibited growth appears to be in response to a maximum transpiration rate that can be supported by the tall fescue plants. The sensitivity to VPD indicates that if VPD remains stable in future climates as it has in the past, growth of tall fescue could well be stimulated rather than decreased by global warming in temperate climate zones.}, number={1}, journal={Planta}, publisher={Springer Science and Business Media LLC}, author={Sinclair, Thomas and Fiscus, Edwin and Wherley, Ben and Durham, Michael and Rufty, Thomas}, year={2007}, month={Oct}, pages={273–276} }
 @article{gardner_wherley_2005, title={Growth response of three turfgrass species to nitrogen and trinexapac-ethyl in shade}, volume={40}, number={6}, journal={HortScience}, author={Gardner, D. S. and Wherley, B. G.}, year={2005}, pages={1911–1915} }
 @article{wherley_gardner_metzger_2005, title={Tall fescue photomorphogenesis as influenced by changes in the spectral composition and light intensity}, volume={45}, DOI={10.2135/cropsci2005.0562}, abstractNote={The influence of deciduous foliage shade on turfgrass development has not been fully investigated. Previous research neglects changes in spectral distribution, e.g., red:far‐red light (R:FR) ratios common of foliage shade. Turfgrass plants may respond simultaneously but in different ways to changes in light intensity and spectral composition. A field study was conducted in 2001–2002 at the Ohio Turfgrass Research and Educational Facility, Columbus, OH. Two tall fescue (Festuca arundinacea Schreb.) cultivars of differing shade tolerance were established under low photosynthetic photon flux (PPF) in approximately 8% of full sunlight with high (>1) and low (<1) R:FR ratios to distinguish between developmental effects of R:FR ratio (spectral composition) and PPF (light intensity) on turfgrass photomorphogenesis. Few morphological differences in shade tolerance between the two cultivars were observed during the 2‐yr study. However, under low PPF, high R:FR ratios led to increased tillering, leaf blade width and thickness, and chlorophyll contents. Root mass declined under reduced PPF regardless of R:FR ratio. Results suggest that while turfgrass photomorphogenesis in shade is influenced by changes in PPF, many characters are further influenced by changes in the R:FR ratio.}, number={2}, journal={Crop Science}, author={Wherley, B. G. and Gardner, D. S. and Metzger, J. D.}, year={2005}, pages={562–568} }