Wednesday, November 15, 2006

Late and Early Season Growth and Physiological Responses of Riviera Bermudagrass as Modified by Turf Blankets.

James Goatley1, Xunzhong Zhang2, Erik Ervin2, David McKissack2, Shawn Askew2, Brandon Horvath2, and Kevin Hensler2. (1) Mississippi State University, Virginia Tech, 424 Smyth Hall CSES Dept., Blacksburg, VA 24061, (2) Virginia Tech, 424 Smyth Hall CSES Dept., 424 Smyth Hall CSES Dept., Blacksburg, VA 24061, United States of America

Utilizing turf blankets in the fall and spring to provide frost protection and modify temperatures can extend the growing season of bermudagrass by weeks, potentially improving quality, growth, and playability of golf and sports turfs.  However, how do differences in blanket color and source affect bermudagrass response?  This research evaluates various performance characteristics of ‘Riviera' bermudagrass following a fall installation of polypropylene blankets (black and white) and a reflective mesh netting immediately prior to the first killing frost events of 2004-05 and 2005-06 in Blacksburg, VA.  Black blankets generally had the greatest impact on canopy surface temperatures, resulting in the highest average daily temperatures and highest average temperature ranges.  All blankets provided acceptable turf quality and promoted late season growth through November in each season, but as air temperatures significantly cooled during late fall,  the highest quality ratings were consistently observed for black blankets.  Maintaining bermudagrass color by the use of any turf blanket resulted in greater photochemical efficiency measurements than the uncovered control through late fall.  However, during spring greening, the lack of radiant energy passing through black blankets resulted in significantly lower green-up, color, quality, and photochemical efficiency ratings as compared to all other treatments.  Turf blankets generally had no significant effects on total nonstructural carbohydrate (TNC) levels of sampled rhizomes except for March 2005 when all blanket treatments had significantly greater TNC levels.   Reflective netting applied alone generally resulted in some of the highest color and quality ratings in mid-spring evaluations.  The addition of the reflective netting to either black or white blankets did not consistently alter measured turf responses as compared to black or white blankets applied alone.  White and reflective blankets provided the most flexibility for manipulating bermudagrass responses during suboptimal growing periods, but black blankets maintained the best turf quality in late fall.