Tuesday, November 14, 2006

The Use of Plant Growth Regulators to Improve the Wear Tolerance and Repair of Overseeded Bermudagrass.

Chris Marshall, Xunzhong Zhang, Mike Goatley, and Erik Ervin. Virginia Polytechnic Institute and State University, 335 Smyth Hall, CSES Dept, Blacksburg, VA 24061-0404

An active football season during the fall acclimation period tests the wear tolerance of bermudagrass.  Exogenous applications of synthetic cytokinins or cytokinin-enhancing plant growth regulators, such as trinexapac-ethyl, may improve the wear tolerance of ‘Patriot’ and ‘Tifsport’ bermudagrasses.  This study is designed to mimic the agronomic practices and wear stresses experienced at Virginia Tech’s Worsham Field.  Starting in September 2005, wear treatments were performed using a differential-slip wear simulator.  Following a wear treatment, plots received an application of one of three PGRs: 6-Benzyladenine (6-BA), 2-Chloro-4-pyridyl-phenylurea (CPPU) or Trinexapac-ethyl (Primo Maxx).  Physiological and morphological responses such as total non-structural carbohydrates and turf density are being measured.  Increases to tissue cytokinin have been shown to increase tiller density, improve anti-senescence properties and enhance photochemical efficiency.  For these reasons, the application of cytokinin enhancing PGRs are believed to have potential to increase bermudagrass wear tolerance.  Patriot’s aggressive growth and excellent cold hardiness are predicted to give it better overall wear tolerance and repair as compared to ‘Tifsport’.  Cultivar by PGR interactions in terms of wear tolerance will also be discussed.