Journal or Publishing Institution: Outlooks on Pest Management
Author(s): Blake, R. and Pallett, K.
Article Type: Journal Publication
Abstract:
All pesticides used in agriculture undergo an extensive range of science-based regulatory studies to answer a number of environmental questions on the active substances and representative formulations. Accordingly, glyphosate has been evaluated in many regulatory studies to determine whether it: degrades after application and if so, what degradation products are formed?; persists in soil and, if so, is there residual herbicidal activity in soil?; persists in water or sediment?; leaches through soil to reach groundwater; moves from treated areas as runoff to surface water; moves from treated areas as a vapor?; accumulates in tissues of animals?; is harmful to animals, invertebrates, non-target plants and microorganisms? Glyphosate is a highly effective herbicide in part due to enoylpyruvylphosphate synthase (EPSPS) being a unique and phytotoxic target site but also due to its physicochemical properties. Specifically, its water solubility (11.6 g/L at 25°C) and low lipophilicity (LogP <-3.2 at 20°C) and a dissociation constant (pKa) of 2.3 at 25°C which lead to a high systemicity in plants. Following foliar uptake, these properties lead to high translocation in the phloem to meristematic tissues throughout the plant. The principle environmental degradation product of glyphosate is aminomethylphosphonic acid (AMPA), which has been tested in a number of environmental and ecotoxicity studies. The physicochemical properties of glyphosate and AMPA, particularly the high water solubility, raise potential concerns for leaching via soil to ground water and run-off to surface waters, and the subsequent impact on organisms living in these environmental compartments. This review aims to summarise the current state of knowledge on the fate, behaviour and ecological effects of glyphosate in these different environmental compartments.
Keywords: Glyphosate, AMPA, pesticides, herbicides, agriculture, ecotoxicity, regulation
Citation:
Blake, R. and Pallett, K., 2018. The environmental fate and ecotoxicity of glyphosate. Outlooks on Pest Management, 29(6), pp.266-269.
Category:
- Environmental effects
- Regulatory issues
- Pesticide use
Record ID: 2463
