Abstract: Kyllinga squamulata has become problematic in bermudagrass turf in recent years, probably related to shifts in herbicide use strategies. Preemergence and postemergence greenhouse and field herbicide studies evaluated K. squamulata control in bermudagrass turf. Excellent (≥90%) postemergence control at 6 wk after initial treatment (WAIT) followed single and sequential applications of imazaquin at 0.42 kg ai/ha, MSMA plus imazaquin at 1.12 0.42 kg ai/ha, and sulfentrazone at 0.56 kg ai/ha. In one of two experiments, unacceptable (>30%) bermudagrass injury occurred with imazaquin at 0.42 and 0.56 kg ai/ha and MSMA plus imazaquin at 1.12 0.42 kg ai/ha 1 wk after application; however, plots recovered fully by 2 wk. In the field at 18 WAIT, preemergence control of greater than 70% was obtained with a single application of oxadiazon at 1.12 or 2.24 kg ai/ha and sequential applications of 1.12 kg ai/ha each 8 wk apart. Sequential applications 8 wk apart of sulfentrazone at 0.28 followed by 0.28 kg/ha also provided greater than 70% preemergence control. In two greenhouse studies, oxadiazon at 2.24 kg/ha and sulfentrazone at 0.56 kg/ha provided greater than 90% preemergence control.

Nomenclature: Imazaquin; MSMA; oxadiazon; sulfentrazone; cock's comb kyllinga (proposed common name), Kyllinga squamulata Thonn. ex Vahl; hybrid bermudagrass, Cynodon dactylon Burtt-Davey × C. transvaalensis L. Pers. ‘Tifway’.

Abbreviations: fb, followed by, WAIT, weeks after initial treatment, WAT, weeks after treatment.