Susceptibility of American burnweed (Erechtities hieraciifolius) to herbicides and clipping in wild blueberry (Vaccinium angustifolium Ait.)

American burnweed is an increasingly common annual weed in wild blueberry fields in Atlantic Canada. Knowledge of susceptibility to several common herbicides used in wild blueberry, however, is lacking, and it is unclear how burnweed responds to clipping. Using greenhouse-grown plants, the objectives of this research were to evaluate burnweed susceptibility to various herbicides registered in wild blueberry and to determine the effect of clipping on burnweed lateral branch and flower production. Postemergence broadcast applications of mesotrione, flumioxazin, glufosinate, clopyralid, foramsulfuron, glyphosate, tribenuron methyl, nicosulfuron/rimsulfuron, terbacil, and hexazinone provided >90% control of burnweed. Postemergence spot applications of clopyralid, glyphosate, mesotrione, and nicosulfuron/rimsulfuron to 24 ± 0.3 cm tall burnweed plants caused 60%–97% injury, but