G.L. Graham
Abstract: Smooth bedstraw (Galium mollugo) is becoming a serious weed in pastures, hayfields and field
margins across the Maritime region. Its invasive nature allows this plant to out-compete forage species, reducing the value
of the stand. A trial was established in a high input forage mixture with an infestation of smooth bedstraw near
Scotch Lake, New Brunswick. All herbicide treatments had significantly improved grass coverage as compared to the untreated
control, with low levels of grass injury. All tested herbicides significantly decreased clover populations within the season
of application. Natural clover re-introduction within the second season was noted within many treatments. A high level of smooth
bedstraw control was found from all aminopyralid and triclopyr treatments over both evaluation years. DPX-MAT was also effective,
with improved control at higher use rates. Dandelion (Taraxacum officinale) control within the trial was highly variable,
represented by a high LSD value within all evaluations. A significant rate effect was present for triclopyr and dandelion control,
while aminopyralid alone or with 2,4-D controlled dandelion at all tested rates. A high rate of DPX-MAT was required for dandelion
control. MCPA amine and mecoprop/MCPA/dicamba suppressed dandelion populations within the season following application and were not
effective for smooth bedstraw control. Aminopyralid and triclopyr are the best registered options for smooth bedstraw control in
New Brunswick forage production. DPX-MAT has promise for smooth bedstraw control and should be evaluated further to determine the
weed control spectrum of this new product. To ensure the proper herbicide choice in forage, producers must consider the spectrum of
plants present in the field as well as herbicide price.
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