Monday, November 5, 2007
75-13

Response of Twenty-Five Warm Season Turfgrasses to Sixty-Day Drought: Turf Quality, Color and Leaf Firing.

David Chalmers1, Kurt Steinke1, Richard H. White1, James Thomas1, and Guy Fipps2. (1) Soil and Crop Sciences, Texas A&M University, 2474 TAMU, College Station, TX 77843, (2) Biological and Agricultural Engineering, Texas A&M University, College Station, TX 77843

Research evaluated 25 turfgrass cultivars grown in four replications, on restricted (10.2 cm) and unrestricted (43+ cm) soil depths, during a 60-day summer drought, in 2006 and 2007 in San Antonio, Texas. Grasses were sodded to separate experimental areas in September 2005 and September 2006 for imposed drought in 2006 and 2007, respectively. Drought was maintained by a 5,000 sq. ft. “drought simulator” (rain-out shelter) which covered plot area during rainfall to maintain a 60-day summer drought period. Grasses were evaluated for turfgrass quality, color, and leaf firing response during drought. The 2006 drought caused severe moisture stress on the 10.2 cm soil depth after 6 days and grass leaves were completely brown 20 days into drought. The period in time to leaf firing varied between grasses on the native soil depth in 2006. Differences between species were most evident beginning 33 days into drought. Buffalograss and most bermudagrass cultivars exhibited the greatest resistance to leaf firing while St Augustinegrass and zoysiagrass cultivars were most affected. Zoysigrass cultivars appeared dormant without any green color after 40 days of drought. Data will also be reported from the 2007 drought, a repeat of the 2006 drought on the same grasses established in a separate plot area from the 2006 study.