Use Caution When Selecting Adjuvants

Mark VanGessel, Extension Weed Specialist;

The weather patterns lately have resulted in situations where the risk of crop injury from postemergence herbicides is higher. Specifically, prolonged periods of overcast skies, cooler weather, and plenty of rain. If postemergence herbicides are made as the days turn hot and sunny, the risk of injury is greater. This because the wax layer on the leaves has not developed and the leave surface is “tender”. If spraying during these sensitive periods, switch to “softer” additives if the label allows it; for instance MSO increases the risk of injury over COC; and non-ionic surfactants (NIS or 80-20’s) reduces the risk further. Consider using the lower allowed rate of the surfactant or nitrogen. Be sure to read the label and see what is allowed by the manufacturer.