In the July issue of AgProfessional magazine, an article—“Roundup Ready Xtend Crop System”—I included what I thought was a correct quote that contended there hasn’t been a weed showing full resistance to both glyphosate and dicamba herbicides.
It appears that I misquoted the Monsanto representative, although it was my understanding that the quote had been checked as accurate. I say there apparently is an error in the statement because a Kansas reader of the magazine provided real-world experience using glyphosate and dicamba together without achieving full weed control.
“This [claim] is not correct because for the past 3-4 years in northwest Kansas we cannot kill kochia with 44 ounces of Roundup 6 pounds (label rate is 22 ounces) plus 16 ounces of dicamba and AMS if the kochia gets more than 1/2 - 1 inch tall. What use to be Sandoz, then BASF, had been tracking dicamba resistance in kochia since the 60's,” wrote Ryan Inman.
Inman is self-employed with REI Agronomy Services, LLC and for 13 years was with Servi-Tech Inc. “The resistance is based on personal experience as he explained with his detailed account. He said he has observed the problem continue to increase to a wider area. His observation comes from field spray records made by producer clients and him personally operating an applicator “trying different rates and mixes.”