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Selecting Cultivars Based on Specific Performance Characteristics Sustainable Turfgrass Management in Asia 2012. Doug Karcher Associate Professor Department of Horticulture University of Arkansas. karcher@uark.edu turf.uark.edu. Tifway hybrid bermudagrass. Sod or sprigs.
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Selecting Cultivars Based on Specific Performance CharacteristicsSustainable Turfgrass Management in Asia 2012 Doug KarcherAssociate ProfessorDepartment of HorticultureUniversity of Arkansas karcher@uark.edu turf.uark.edu
Tifway hybrid bermudagrass Sod or sprigs
Riviera bermudagrass Seeded
Propagation types • Seeded • Zoysia japonica • Vegetative • Zoysia japonica • Zoysia matrella var. matrella
Why zoysia seed? Summary of establishment methods and costs for zoysiagrass. 1193K baht/ha 375K baht/ha 225K baht/ha 84K Baht/ha
Zoysiagrass establishment rate LSD0.05 = 0.0047 Z. japonica Z. matrella
Trinexapac-ethyl PrimoFairway Experiment • Finer, tighter, and more upright for the treated plot
Sunsport Contessa Veracruz Sovereign Barbados Sultan From: Baldwin, C. M., H. Liu, and L. B. McCarty. 2008. Diversity of 42 bermudagrass cultivars in a reduced light environment. Acta Hort. (ISHS) 783:147-158.
Perceptions about bermuda vs. zoysia • Bermudagrass has a faster growth rate • More clippings • More scalping • Faster divot recovery • Zoysiagrass has higher density • Better ball lie
Bermuda vs. Zoysia Experiment • Plots evaluated over 2 growing seasons, once established. • Plots were mown at 1.3 cm (0.5 in). • 40 kg N ha-1 per growing month for bermudagrass and 25 kg N ha-1 for zoysiagrass.
Growth Rate (clippings) • Clippings were harvested by making two passes in the opposite direction over the same plot. • Clippings were then collected and oven dried at 80 °C for four days. • Dry weights were recorded to quantify clipping yield.
Scalping • Evaluated using digital image analysis • Digital photos taken under controlled lighting conditions and analyzed for % green
Digital image analysis used for scalping tendency • Scalping tendency (%): • [100*((percent green turf before mowing - percent green turf after mowing)/percent green turf before mowing)]. Before mowing 99.4% coverage 22.9% Scalping 76.6% coverage After mowing
Clipping Yield & Scalping Results • The cultivars with lowest clipping yields were Diamond , Meyer, and Patriot. • Palisades, Princess 77, and Tifway had the highest amount of clippings. • Patriot and Tifsportbermudagrass had the highest scalping across the two years of this study. • All other cultivars had minimal scalping
Golf Ball Lie Zorro zoysiagrass Zorro zoysiagrass: 98% ball exposed Palisades zoysiagrass Palisades zoysiagrass: 73% ball exposed
Ball Lie Results • When mown, no differences in ball lie. • Palisades zoysiagrass had the poorest ball lie in unmown conditions.
Divots ~ 0.2 ha turf removed annually per fairway by divoting.
Previous divot recovery research • Bermudagrass (Karcher et al., 2005a) • 2003 results: Riviera, Princess 77, and Patriot > Tifway, Tifsport. • Zoysiagrass (Karcher et al., 2005b) • Palisades, Cavalier, and Zorro had the fastest recovery times. • Meyer consistently had the slowest recovery times. • Although these (Karcher et al., 2005a,b) studies were not performed in the same experiment, they were performed at the same time and location (Fayetteville, AR). • The amount of time required to reach 50% recovery was similar between bermudagrass and zoysiagrass.
Our understandings of divoting • Recuperative potential • Divot recovery vs. divot resistance More susceptible to divoting Less susceptible to divoting
Materials and methods: divot recovery • Plots were divoted on: • 7 July 2008 • 25 August 2008 • 21 May 2009 • Three (subsamples) standardized divots (5 x 10 cm) were taken from each plot using a modified edger (Fry et al., 2008).
Tifwaybermudagrass at day 0 after injury (top) and at day 9 after injury (bottom) Percent recovery was calculated as: 100 * [(%coverx - %cover0) / (100% - %cover0)] day 0 after injury 0% recovery day 9 after injury 72% recovery
Divot Evaluations • Severity • 1 = Very small divot, little to no damage • 2 = Small divot, some injury • 3 = Moderate divot size or disruption • 4 = Large divot • 5 = Worst (very large divot) or severe injury
Summary – divot recovery • Those cultivars with the fastest time to 50% recovery were • Princess 77 and Riviera bermudagrass • Palisades zoysiagrass • Bermudagrasses recovered faster than zoysiagrasses • Keep in mind, these divots were created mechanically
Divot resistancealso differs among cultivars Riviera bermudagrass Diamond zoysiagrass
17 July and 1 September 2009 results – divot severity • Severity
Divot Conclusions • Zoysiagrasses tended to have a greater divot resistance. • Z. matrellacultivars (Cavalier, Diamond, and Zorro) consistently had the greatest divot resistance. • Perceived increases in ball lie of zoysiagrass may be a function of greater divot resistance
Summary Points • Keep your eye on improved, seeded cultivars • Within species, cultivars vary in establishment, growth rate, traffic tolerance, and divot resistance and recovery • Utilize best adapted species and cultivars to minimize inputs needed to produce quality turf • Current & Future Research • Shade , drought, disease, low management inputs
Acknowledgements • Conference organizers • Asian Turfgrass Center • Thai GCSA • The R&A • Dr. Micah Woods