| Bermudagrass (Cynodon spp.) is the most popular warm-season turfgrass used in warm climatic regions of the world due its recuperative ability, high traffic tolerance, heat tolerance, and relative drought and salt tolerance. Primary objectives of this dissertation were to determine the genetic diversity of bermudagrasses grown in full-sunlight and shade, impacts of shade and cultural practices on bermudagrass spring transition, management recommendations to enhance bermudagrass putting greens under shade, and the impact of different types of light on warm-season turfgrasses. Secondary objectives of this dissertation determined winter shade and traffic impacts on creeping bentgrass putting greens.;Two lysimeter studies were conducted from March to July 2006 and 2007 to evaluate fairway-type bermudagrass cultivars spring green-up (SGU) when shade is a growth limiting factor and to evaluate the impacts of different cultural practices (overseed, colorant use, and dormant turfgrass) and shade on ‘TifEagle’ bermudagrass (Cynodon dactylon (L.) Pers. X C. transvaalensis Burtt-Davy) spring transition and summer performance. This study indicates colorant-use may provide an alternative to overseeding for bermudagrass by providing adequate winter color at certain sites and a stronger bermudagrass base compared to overseeding.;A two-year field study from 15 June to 15 September 2006 and 2007 at Clemson University determined the best combination of management practices for sustaining a high quality ‘Champion’ bermudagrass putting green under shade. Treatments included 55% full-day shade, trinexapac-ethyl (TE) applications (0.05 kg a.i. ha-1 2wk-1), iron (Fe) applications (2.7 kg a.i. ha-1 2wk-1), and nitrogen (N) applications as urea (46-0-0) at rates of 147, 293, and 437 kg ha-1 yr-1. Champion bermudagrass did not provide an acceptable quality putting green when grown under 55% full-day shade, however, adjusting chemical and cultural management practices improved Champion bermudagrass putting green when grown under shade.;In 2007, two repeated greenhouse research projects were initiated to investigate the physiological and morphological responses of ‘Diamond’ zoysiagrass (Zoysia matrella (L.) Merr), ‘Sea Isle 2000’ (Paspalum vaginatum Sw.) seashore paspalum, Tifway bermudagrass, and Celebration bermudagrass to various light spectral qualities. Light treatments included a full-sunlight control and four different color shade cloths. Overall, black shade most negatively inhibited parameters measured followed by blue shade, while yellow and red shade performed similarly. For turfgrasses, Diamond was the most shade-tolerant, while Tifway was the most shade-sensitive. Celebration and Sea Isle 2000 performed similarly. This study implies different types of shade significantly impact the performance of warm-season turfgrasses.;Two replicated field studies were conducted to evaluate winter shade tolerance under various reduced light environments and winter traffic tolerance of ‘L93’ creeping bentgrass (Agrostis stolonifera var. palustris (Huds.)). In the first field study, objectives were to evaluate winter shade tolerance of ‘L93’ creeping bentgrass under various reduced light environments (55% and 95%), including effects of morning vs. afternoon shade, effect of trinexapac-ethyl (TE) (4-(cyclopropyl-α-hydroxy-methylene)-3,5-dioxy-cyclohexanecarboxylic acid ethyl ester) application on shade tolerance, and summer month performance following a winter shade environment. In a separate field study, treatments consisted of no traffic (control), foot traffic, and walk behind mower traffic (rolling) at 0700 and 0900 when canopy temperatures were at or below 0°C. Under traffic stress, on all TQ rating dates, 0700 rolling traffic decreased TQ by ∼1.1 units compared to foot traffic at 0700. This study indicates bentgrass damage due to winter traffic is limited to winter and early spring months and full recovery should be expected by summer. (Abstract shortened by UMI.). |
