DOWNY BROME (<i>Bromus tectorum</i>) INVASION INTO SOUTHWESTERN SASKATCHEWAN

Downy brome (Bromus tectorum L.) has rapidly invaded crop and pasture land in southwestern Saskatchewan since 1960. By 1989, 116 townships in 31 rural municipalities were infested. The spread of downy brome is associated with the increased area of winter wheat and fall rye grown using minimum and zero tillage practices, a lack of effective herbicides for selective in crop control and weather conditions which favor autumn germination and early spring competition. Although downy brome has been found on seven soil associations in the Brown soil zone and one association in the Dark Brown soil zone, the occurrence of the weed is related to cropping practices rather than soil texture or association.Key words: Downy brome distribution, downy brome invasion, Bromus tectorum, winter wheat