Agriculture, Aquaculture and Fisheries - Evaluation of Herbicide Options for Black Bulrush (<i>Scirpus atrovirens</i>) within Cranberry Production, including Mesotrione

Abstract: Competition from weeds in cranberry beds continues to be a production limitation in New Brunswick. Sedge species, including black bulrush (Scirpus atrovirens), are problematic for producers as they survive well in cranberry production. in previous evaluations, mesotrione has shown activity on sedge species although the level of control can be quite variable. Another product, nicosulfuron/rimsulfuron, is utilized in lowbush blueberry production to control sedges and should be evaluated within cranberry production. A trial was initiated near Saint Charles, New Brunswick in an established cranberry bed. Mesotrione was effective in controlling this sedge species. An earlier application would be preferred over the later application, as control was significantly reduced in the late application. A split application of the registered mesotrione rate at both timings improved weed control, while a split application at the lower mesotrione rate gave control similar to the early treatment alone. A split application may have some utility in cranberry production, especially on more difficult to control weed species. No significant change to weed control or crop tolerance was noted when mesotrione was mixed with sethoxydim. Nicosulfuron/rimsulfuron caused early crop injury, but plants recovered by the end of the trial with no significant yield effect. Weed control from this product was excellent.