Wednesday, November 7, 2007
268-14

Annual Nitrogen Rate and Mowing Height Contribute to 'TifBlair' Centipedegrass (Eremochloa ophiuroides) Decline.

Freddie Waltz and Wayne Hanna. 1109 Experiment St., University of Georgia, University of Georgia, C&SS Redding Bldg., Griffin, GA 30223-1797

Centipedegrass (Eremochloa ophiuroides) is a commonly used home lawn turfgrass species in the southern and southeastern USA.  Relative to other warm-season turfgrasses, it is maintained with lower annual nitrogen fertility and management inputs to produce an acceptable turfgrass sward.  In 2003, a study to investigate the long-term interactions of various nitrogen rates and mowing heights was initiated at two locations in Georgia, Griffin and Tifton.  The studies were established in existing stands of ‘TifBlair’ centipedegrass and plots were treated the same for each location during the three subsequent years.  Mowing heights of 3.8 and 7.6 cm were maintained and fertilized with six nitrogen rates either as a single application in May (24.5, 49.0, 98.0 kg ha-1) or sequential applications in May and August (24.5 + 24.5, 49.0 + 49.0, and 98.0 + 98.0 kg ha-1).  A seventh treatment of 24.5 kg ha-1 was applied four times in March, May, July and August.  A nontreated control was also included where no nitrogen was applied for four years.  Compared to two sequential 24.5 kg ha-1 applications, spring green-up was reduced in plots treated with single and repeat applications of nitrogen at 98.0 kg ha-1.  Green-up of the 7.6 cm centipedegrass lagged behind the lower mowed plots.  Similarly, the turfgrass quality was better in the 3.8 cm grass compared to the 7.6 cm cutting height.  Spring green-up was delayed following three consecutive years of 196.0 kg ha-1 applied annually and mowed at 7.6 cm.  Plots with an annual nitrogen application rate of 49.0 kg ha-1 and mowed at 3.8 cm were superior in green-up and turfgrass quality.  From these trials and previous research reports, the proper nitrogen rate for centipedegrass is 49.0 kg ha-1 to 98.0 kg ha-1 per year and should be mowed at 3.8 cm.