Almost 75% of the Iowa fields which the University of Illinois tested for weed resistance in 2016 showed resistance to glyphosate and PPO inhibitors among the waterhemp or palmer amaranth weeds tested.
January 19, 2016 By Jerry Carlson — Almost half the fields in Illinois and over 80% of the fields in Missouri checked by the weed scientists showed this type of resistance. Click on this link to see the full report by Diane Plewa and Suzanne Bissonnette.
Oklahoma extension weeds specialist Joe Armstrong has compiled a summary of “mode of action” of most current herbicides; you can download the PDF at this link.
A few of our “biologically friendly” crop consultant friends are reasoning that light cultivation of the top couple of inches for weed control doesn’t seriously disrupt soil microbes in the full aerobic zone of the soil profile. Last June, AgriEnergy Resources offered the first field day we’ve seen on modern cultivation technologies. It was on the Scott Shriver farm near Jefferson, IA.
Weed control with the new generation of implements could be a major means of dealing with the virtual certainty of herbicide resistance. It can also offer an opportunity to foliar feed crops and side-dress nutrients as indicated by tissue tests.