Selection of Bermudagrass Germplasm That Exhibits Potential Shade Tolerance.

Bermudagrass is highly recommended for home lawns as well as golf courses in the southern United States.  Bermudagrass has relatively good heat and drought tolerance, and is resistant or tolerant to most diseases and insect pests.  However, bermudagrass does not tolerate shade nearly as well as most grasses.  It is difficult to maintain quality bermudagrass on shaded areas where limited sunlight is available.  The objectives of this study were to screen bermudagrass selections for their effectiveness in shaded environments and to determine turfgrass characteristics that may be useful for rapid screening future selections for potential shade tolerance.  The research site was constructed for this project at Oklahoma State University in Stillwater, OK.  Vegetative samples of forty five experimental lines along with four control varieties were planted on June 22, 2007.  Each experimental sample was replicated five times in sun and five times in shade.  The research area was mowed at 3.8cm and irrigated as needed.  Turfgrass overall visual quality and Normalized Difference Vegetative Index (NDVI) were measured nine times during the growing season in 2008.   Digital images were also taken to determine percent cover.  In 2008, the research area was shaded by evergreen trees for about twenty percent each day.  Experimental lines #4, # 13, #17, and #19 exhibited the most shade tolerance in 2008 while experimental lines #32, #83, and #84 were least shade tolerant.