Thursday, November 8, 2007 - 9:30 AM

Evaluation of Competition Amongst Turf Bermudagrasses During Establishment Phase.

Holly Han, Dennis Martin, Greg Bell, Charles Taliaferro, Nathan Walker, and Yanqi Wu. 360 Agricultural Hall, Oklahoma State University, Dept. of Horticulture & Landscape Architecture, Stillwater, OK 74078-6027

Many improved turf-type bermudagrasses (Cynodon species) have become commercially available during the 1990s to present. Utilization of improved varieties is often confounded due to inability to eradicate existing bermudagrasses. Subsequently, the newly installed variety often becomes contaminated with preceding types resulting in reduced visual and functional quality of the turf. Patriot (OKC 18-4), TifSport (Tift 94) and Tifway (Tifton 419) interspecific hybrid bermudagrasses (C. dactylon X C. transvaalensis) were evaluated for their ability to compete against an aggressive locally adapted turf-type common bermudagrass (C. dactylon ‘TGS U-3') under golf course fairway conditions (1.3 cm mowing height). To assess intra-species competition, newly sprigged plots of each variety were contaminated with three sprigs per plot (4 cm in length) of the contaminant TGS U-3. Colonization (percent living cover) of the plot by the designated cultivar and the contaminant was visually assessed at 0, 2, 4, 6, and 8 weeks after sprigging and thereafter once per month through Oct 2006 using a 100 point grid. Sprigging was conducted on 9 June (time 0) at 21 m3 ha-1 with the contaminant placed on 15 June. Patriot provided significantly higher living cover (52, 95 and 99%) on 26 June, and on 14 and 31 Jul than did TifSport or Tifway. TifSport cover (9, 44 and 67%) did not differ from Tifway cover (9, 42 and 64%) on these same sampling dates. TGS U-3 cover on 14 Jul averaged 4, 0.2 and 5% (LSD = 1) in the TifSport, Patriot and Tifway plots while on 31 Jul it averaged 21, 0.5 and 23% (LSD=4), respectively. The findings of this first season's research suggest that in Oklahoma Patriot colonizes ground more rapidly than either Tifway or TifSport and more effectively competes against a localized aggressive common bermudagrass than does Tifway or TifSport.