Research Branch

See below to download.

Ten-year Conifer and Vegetation Responses to Glyphosate Treatment in the SBSdw3

Author(s) or contact(s): B.S. Biring and W.J. Hays-Byl
Source: Research Branch
Subject: Vegetation Management
Series: Extension Note
Other details:  Published 2000. Hardcopy is available.


In forestry, vegetation management treatments are widely used to enhance establishment of young stands and achieve free growing requirements. In 1988, an operational herbicide monitoring trial was established in a 1-year-old white spruce (Picea glauca) plantation in the SBSdw3 biogeoclimatic zone to examine the effectiveness of glyphosate herbicide on a vegetation community. The study consists of two 1 ha treatment plots, one of which was treated with aerially applied glyphosate at a rate of 2.14 kg a.i./ha. Ten years after treatment, glyphosate had increased height and basal diameter, reduced height-to-diameter ratio, and improved vigour of white spruce. Eleven years after planting, the glyphosate treated plot had significantly greater number of free growing spruce per ha, and significantly less percent cover and density of broadleaves than the untreated control plot. However, the treatment did not affect the plant species richness. Yield projections for white spruce an trembling aspen based on MGM suggest that treatment applied to control broadleaves and shrubs has the potential to increase conifer yield and reduce conifer rotation age.

Download Extension Note 48 PDF file (593 KB)

To view this document you need the current version of
Adobe Acrobat Reader, available free from the Adobe Web Site.

Updated April 19, 2007