The Influence of Glyphosate on Mineral Content of Glyphosate-Resistant Crops.

Claims have been made that glyphosate reduces content of certain divalent metal cations such as Mn⁺⁺ in glyphosate-resistant (GR) crops, thereby affecting yield and resistance to plant pathogens.  The proposed mechanism of such an effect is through the chelating properties of the glyphosate anion.  This paper reviews the literature on this topic, and finds evidence for adverse effects on mineral nutrition of GR crops to be extremely weak. This conclusion is based on: 1) growing numbers of studies that find no significant effects on mineral content of GR crops; 2) lack of evidence of any adverse effects of glyphosate on yield of GR crops; and 3) growing evidence that glyphosate had little or no adverse effects on host plant resistance to pathogens in GR crops.