Wednesday, November 7, 2007
268-20
Altered Light Spectral Qualities Impacts on Warm-Season Turfgrass Growth and Development.
Christian Baldwin, Haibo Liu, Nihal Rajapakse, Lambert McCarty, Hong Luo, and Joe Toler. Horticulture, Clemson University, 143 P & A building, Clemson, SC 29634
A turfgrass stand under shade can be inhibited by reduced photosynthesis, increased disease pressure due to extended morning dew duration, reduced carbohydrate production, tree root competition and reduced lateral stem growth. Another factor affecting turfgrass growth and development under tree shade is various qualities of light filtered by trees. However, effects of various filtered wavelengths on turfgrass performance are lacking and deserve research. Therefore, a greenhouse project investigated the physiological and morphological responses of ‘Diamond’ zoysiagrass (Zoysia matrella (L.) Merr), ‘Sea Isle 2000’ (Paspalum vaginatum Sw.) seashore paspalum, ‘Tifway’ bermudagrass (Cynodon dactylon X cynodon transvaalensis), and ‘Celebration’ bermudagrass (C. dactylon X c. transvaalensis) to various light spectral qualities. Light treatments included a full-sun control and four different color shade cloths filtering wavelengths 560 - 720 nm (blue shade cloth), 360 – 520 nm (yellow shade cloth), 360 - 560 nm (red shade cloth) and 360-720nm (black shade cloth). Red to far red ratio for each cloth was ~1.171, while percent light reduction for each cloth was ~65%. All turfgrasses were placed in lysimeters 15 cm in diameter and 46 cm in height filled with 10.14 cm of gravel and 30.48 cm of 85% sand and 15% peat as growth media and allowed four weeks to establish in a greenhouse before shade treatment initiation. Data collection included visual turfgrass quality, clipping yield, total shoot chlorophyll, leaf width, total root biomass, root length density, specific root length, and root and shoot total non-structural carbohydrates. Complete results will be presented at the conference.