Materials and Methods
Field studies were conducted during late spring/early summer of 2011 and 2012 at the Texas A&M University Turfgrass Research Field Laboratory, College Station, TX. In 2011, trials were initiated on 1 June 2011, and carried out until 12 August 2011. The 2012 trials were initiated on 2 May 2012, and carried out until 26 June 2012. The studies were conducted on an established stand of common bermudagrass (Cynodon dactylon L. Pers), intermixed with slender aster (Aster subulatus var. ligulatus Shinners) at the 3 to 4-leaf stage, and approximately 7 cm tall at treatment. Soil at the site was a Lufkin fine sandy loam soil with a pH of 9.8. Field plots were arranged as a randomized complete block design (RCBD) with four replications. Individual plots measured 0.91 mx0.91 m with a 0.3 m buffer between plots Turfwas mowed weekly to a height of 6.4 cm. Just prior to initiation, the study area was fertilized at a rate of 49 gN ha using 46-0-0 (N: P: K) urea fertilizer.