Fire effects on four growth stages of smooth brome (Bromus inermis Leyss.)

The invasion and persistence of smooth brome (Bromus inermis Leyss.) are serious problems facing managers of warm-season pastures and prairie remnants in the Midwest. Although difficult to control, smooth brome can be reduced when tiller growing points are removed by management activities such as prescribed fire. This study, conducted from 1988 through 1991 at Mead, Nebraska, measured changes in smooth brome tiller density and biomass in seeded, mixed-grass stands following spring prescription burns. Burning was timed to coincide with four smooth brome growth stages and included repeated burns in consecutive years. Burning at tiller emergence did not affect smooth brome tiller density or biomass in years when precipitation was normal or below normal. However, with above normal precipitation, smooth brome biomass more than doubled the year after a tiller-emergence burn. Burning during tiller elongation, heading, and flowering significantly reduced smooth brome tiller density and biomass. Repeated burns, at tiller elongation and later stages, maintained low smooth brome tiller density and biomass. A single burn, however, allowed partial to full recovery of smooth brome density and biomass by the following year. Implications of the study are presented for management consideration.