Population Dynamics of Downy Brome

Abstract
We investigated the periodicity of germination, longevity of caryopses viability, and reproductive capacity of downy brome (Bromus tectorum L.) populations in relation to chemical and mechanical fallow and fall tillage weed control treatments. The important factors in the dynamics of downy brome populations are: (a) large numbers of viable caryopses are carried from 1 year to the next in the litter and soil; (b) downy brome caryopsis production is density dependent; and (c) the simultaneous germination characteristics of freshly harvested downy brome caryopses can be conditioned environmentally to continuous germination.