|
||||||||||
| Department of Agriculture, Aquaculture and Fisheries |
||||||||||
|
||||||||||
Abstract: Lambkill (Kalmia angustifolia) and rhodora (Rhododendron canadense) are potentially difficult weeds to
control in wild blueberry fields. Dicamba has shown activity in previous research on both weeds, with increased control
when tank–mixed with 2,4–D ester. The effect of 2,4–D ester, in combination with additional
Group 4 herbicides, should be evaluated to determine if the herbicide effect can be increased on these difficult to
control species. A trial was established in the fall after the blueberry harvest in a newly developed wild blueberry field
in the Val Doucet region of New Brunswick. The trial design was a factorial experiment with the main factor
represented by the presence or absence of 2,4–D ester and the sub–factor represented by the Group 4
tank mix partner. A high level of crop injury from 2,4–D ester alone was noted, with higher injury from every
tank mix as compared to the Group 4 blank. No commercially significant yield reduction occurred. The inclusion of
2,4–D ester increased lambkill control for all products and rates tested. Applied alone, 2,4–D ester
suppressed lambkill, with higher control ratings in the tank mix as compared to each herbicide applied singly. All
2,4–D ester plus dicamba, triclopyr or aminopyralid mixes showed lambkill control in the crop year, while a
high rate of dicamba or triclopyr alone suppressed populations. The effect of 2,4–D ester on rhodora was not as
pronounced. Within the crop year, only the high rate of dicamba, either with or without 2,4–D ester consistently
reduced rhodora populations in a commercially acceptable manner. No difference in weed control or crop injury was
noted between the dicamba formulations tested.