Seedbed: What we know and don’t know about manganese deficiency

A review of the research suggests that glyphosate does have an impact on manganese nutrition in Roundup-Ready crops, but that there’s little evidence of a looming crisis


Soon after the introduction of Roundup-Ready (RR) soybeans, there were reports of “yellow flash” following glyphosate application, which looked a lot like manganese deficiency. This resulted in widespread recommendations to include manganese with the glyphosate, leading in turn to poor weed control from inactivation of the herbicide in the spray tank.

Better Farming - May 2010