G.L. Graham and G. Chiasson
Partner: Bleuets NB Blueberries
Abstract: In previous research, dicamba has shown activity on both lambkill (Kalmia angustifolia) and rhodora (Rhododendron canadense),
although suppression of the weed species is common. Glyphosate has proven successful for lambkill control, although regrowth can be noted. No activity is
found on rhodora. The combined use of dicamba and glyphosate may help improve control, as each product used alone does not adequately control both weed species
while the tank mix may control both species. A trial was established in the fall of 2008, after blueberry harvest, in a commercial wild blueberry field in the
Lavillette region of New Brunswick. A low level of crop injury was observed at both dicamba rates tested, although the crop had recovered in subsequent ratings.
Glyphosate alone had a high level of lambkill control. Improved control was observed for dicamba alone at a higher application rate. The addition of glyphosate
to dicamba improved control for lambkill as compared to the equivalent dicamba alone treatment. Dicamba alone suppressed rhodora, with no improvement in control
from the glyphosate tank mixes. As most producers currently use 2,4-D ester to improve dicamba control, the price and weed control difference between glyphosate
and 2,4-D ester should be evaluated.