Silvicultural herbicides in Canada: registration status and research trends

At present, there are five herbicides (2,4-D, glyphosate, hexazinone, simazine, and triclopyr) available to forest managers in Canada. It is unlikely that any new active ingredients will be registered for forestry in the foreseeable future. The only additions likely are extensions of existing labels (e.g., aerial application of Pronone® and Release®) and registration of new formulations (e.g., Velpar® ULW). Research in the short term future will concentrate on improving efficacy, efficiency and versatility, and reducing environmental impact of currently registered products. Some of the current work is described. Key words: silviculture, herbicide, 2,4-D, glyphosate, hexazinone, simazine, triclopyr, research trends, application technology, cost-benefit, vegetation management model, environmental impact