Electrical Conductivity of Five Concentrations of Two Glyphosate-Containing Herbicides

Abstract

Abstract Measuring conductivity of spray solutions of amine herbicides helps assure proper mixing prior to application thus providing additional quality control to operational herbicide programs. Electrical conductivity was determined for seven concentrations (0-15% v:v) of Accord® and Accord® CR herbicides in aqueous solution with three concentrations (0-1% v:v) of either Cide-Kick II™ or Ortho X-77 Spreader® surfactants. Conductivity (μS cm-1) of these solutions, determined at five solution temperatures (5°-25°C), increased 738.7 μS cm-1 and 164.9 μS cm-1 for each 1% increase in herbicide concentration and each 1°C increase in temperature. Conductivity decreased 212.3 μS cm-1 for each 1% increase in surfactant concentration. The conductivity of Accord CR was 100.5 μS cm-1 greater than Accord; conductivity of Cide-Kick II was 82.3 μS cm-1 greater than X-77. The equations presented enable foresters to verify proper concentration and mixing of these herbicide and surfactant solutions for temperatures likely to occur in the field if water source conductivity is ≤300 μS cm-1. South. J. Appl. For. 15(2):85-88.