Bothriochloa ischaemum is an Old World Bluestem (OWB) extensively used throughout the central and southern Great Plains as a forage crop, in roadside plantings, and as a seed component in many USDA-Conservation Reserve Program plantings. Monocultures of OWB have been shown to provide limited value for rodent, bird and arthropod habitat, thus there has been growing interest in converting these OWB monocultures to mixtures of native plant species.   Unfortunately, the conversion practices attempted so far, have proven to be difficult and ineffective.  Thus, our objective was to assess the effectiveness of differing rates of glyphosate (2.125 kg ai/ha and 4.25 kg ai) applied 1 – 3 times in the growing season with or without burning or mowing.  A total of 24 treatments (4 replications; 100 m² plots) were established in May 2007 at the Oklahoma State University Marvin Klemme Range Research Station in western Oklahoma, USA.  Six weeks after treatment we assessed live basal tiller number, frequency of live crowns, foliar cover, and estimated percent control of OWB (relative to control, no herbicide plots) in 3, 1m² quadrats within each replication.  Preliminary results indicate greatest reduction in basal tiller number, frequency of live crowns, foliar cover, and control of OWB with early application of glyphosate at 4.25 kg/ai.