In the early spring before Kentucky bluegrass breaks dormancy and after Kentucky bluegrass shut down for the season in the fall, smooth brome stands out as a course textured patch in your lawn, sod farm, golf course rough, or sports field. During the growing season, its color and texture are comparable to Kentucky bluegrass and is not as much of a nuisance.
Both brome species (Smooth and Downy) can act as weeds in
high quality turf areas. Smooth brome has many desirable characteristics to
function as a useful turfgrass species; however, its poor density limits the use
to low-maintenance areas.
There are several identification traits distinguishing brome
grass from many other weeds. The sheath is nearly closed, giving it a V-neck
sweater appearance. Brome has a rolled vernation, hairy sheaths and blades as
well as a distinctive “watermark” (or W-shaped) on its leaves as seen below in
Photo 1. Its spindly-natured leaves,
small membranous ligule, and winter annual growth habit can usually identify Downy
brome. Brome spreads rapidly by its extension rhizome system and
its seeds are often carried by wind/birds from low maintenance areas to
well-maintained turf.
There is no guaranteed selective control for Smooth brome in
Kentucky bluegrass, creeping bentgrass, or perennial ryegrass turf. Early research
from Zac Reicher and Matt Sousek at the University of Nebraska has shown
earlier year application (June) rather than (July) will aid in Tenacity control
of smooth brome in Kentucky bluegrass. This study will be replicated in 2014
and further data will be passed along as available. Downy brome can be controlled
with the preemergence herbicide Siduron and post-emergent Sethoxydim
(only for use in established fine fescue stands; tall fescue slightly tolerant).
In most cases, a nonselective, systemic herbicide should be
used and multiple applications may be needed to effectively control brome
grass.
Photo 1: Smooth bromegrass’s v-neck sheath and “w-shaped” watermark at midway point of leaf blade. Photo courtesy
of Stephen K. Barnhart, Iowa State Press (1997).
Photo 2. Picture of Downy brome taken this week at the ISU research station. You can see the v-neck sheath as well as fine hairs.
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