Presentation on theme: "Selecting Cultivars Based on Specific Performance Characteristics Sustainable Turfgrass Management in Asia 2012 Doug Karcher Associate Professor Department."— Presentation transcript:
Selecting Cultivars Based on Specific Performance Characteristics Sustainable Turfgrass Management in Asia 2012 Doug Karcher Associate Professor Department of Horticulture University of Arkansas firstname.lastname@example.org turf.uark.edu
El-Toro Zoysiagras (Z. matrella) Country Club of Little Rock
Trinexapac-ethyl Primo Fairway Experiment Finer, tighter, and more upright for the treated plot
Traffic tolerance of various bermudagrass cultivars
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. Contessa Veracruz Sovereign Sunsport Sultan Barbados
CultivarCommon nameSpecies Princess 77BermudagrassCynodon dactylon (L.) Pers. var. dactylon RivieraBermudagrassCynodon dactylon (L.) Pers. var. dactylon PatriotBermudagrassCynodon dactylon (L.) Pers. x. C. transvaalensis Burtt-Davy TifsportBermudagrassCynodon dactylon (L.) Pers. x. C. transvaalensis Burtt-Davy TifwayBermudagrassCynodon dactylon (L.) Pers. x. C. transvaalensis Burtt-Davy El ToroZoysiagrassZoysia japonica Steud. MeyerZoysiagrassZoysia japonica Steud. PalisadesZoysiagrassZoysia japonica Steud. ZenithZoysiagrassZoysia japonica Steud. CavalierZoysiagrassZoysia matrella (L.) Merr. DiamondZoysiagrassZoysia matrella (L.) Merr. ZorroZoysiagrassZoysia matrella (L.) Merr. 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 After mowing 99.4% coverage 76.6% coverage 22.9% Scalping
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 Tifsport bermudagrass had the highest scalping across the two years of this study. All other cultivars had minimal scalping
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 divotingLess 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).
Tifway bermudagrass at day 0 after injury (top) and at day 9 after injury (bottom) Percent recovery was calculated as: 100 * [(%cover x - %cover 0 ) / (100% - %cover 0 )] day 0 after injury day 9 after injury 0% recovery 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 resistance also differs among cultivars Riviera bermudagrassDiamond zoysiagrass
Severity 17 July and 1 September 2009 results – divot severity Species C. dactylon C. dactylon x C. transvaalensis Z. japonica Z. matrella
Divot Conclusions Zoysiagrasses tended to have a greater divot resistance. Z. matrella cultivars (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 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