Canadian Forest Service Publications
Alterations of growth and shikimic acid levels by sublethal glyphosate applications on pin cherry and trembling aspen. 1991. Stasiak, M.A.; Hoffstra, G.; Payne, N.J.; Prasad, R.P.; Fletcher, R.A. Canadian Journal of Forest Research 21(7): 1086-1090.
Issued by: Pacific Forestry Centre
Catalog ID: 3134
Availability: PDF (request by e-mail)
Field experiments were conducted to evaluate the effect of low doses of glyphosate (0.04-0.5 kg/ha) on pin cherry (Prunus pensylvanica L.f.) and trembling aspen (Populus tremuloides Michx.) trees in conifer plantations. Applications were repeated twice over a 2-year period, with treatments applied in late July and growth assessments made 1 and 2 years later. Growth and vigour of these species, measured as percent mortality, visual injury, and leaf and stem lengths, continued to be affected 2 years after treatment even with the lowest rate of glyphosate. Shikimic acid levels were substantially increased within 2 days after herbicide application and could be used to assess glyphosate damage in the field before visual symptoms become apparent.