Uptake and persistence of the herbicide glyphosate (Vision®) in fruit of wild blueberry and red raspberry

Abstract

Field studies on the uptake and persistence of glyphosate (N-(phosphonomethyl)glycine) on wild blueberry (Vacciniummyrtilloides Michx.) and red raspberry (Rubusstrigosus Michx.) under boreal forest (Matheson, Ont.) conditions were undertaken. Uptake studies indicated that less than 10% of glyphosate penetrated the fruit in the first 9 h postapplication. Results of the persistence studies showed a gradual decline in residue levels with time. Times to 50% dissipation for glyphosate residue as determined by curvilinear regression analyses were <20 days (95% confidence limit of 8–26 days) and <13 days (95% confidence limit of 6–14 days) for blueberry and raspberry fruit, respectively. Initial residue levels dissipated to approximately 4 and 6% after 61 and 33 days for the blueberry and raspberry, respectively. Results also showed that at no time during the study period did glyphosate levels in either substrate dissipate to below the maximum permissible residue level (0.01 ppm) as established by Health and Welfare Canada.