Conventional Corn Data

Trial data continues to show that acetochlor-based herbicides like Keystone®, Keystone LA, Surpass®, FulTime® and TopNotch® provide the most consistent grass and broadleaf weed control of all soil-applied herbicides.

  • A tank mix of Keystone + Hornet® WDG herbicides provides a broader spectrum of weed control versus Lumax or Lexar herbicide in one-pass programs.
  • Keystone offers more consistent control of grasses like foxtail since acetochlor activates with only 1/4 inch of rainfall versus 1/2 inch for metolarchlor-based herbicides.


A trial by the University of Illinois reviewed the rainfall activation of an acetochlor-based herbicide like Keystone or Surpass versus a metolachlor-based herbicide. Grass control ratings from the trial showed that an acetochlor-based herbicide outperformed its competitor while requiring only 1/4-inch of rainfall for activation.


Ohio State University extension conducted weed control trials this year at Van Wert, Ohio, where only 0.36 inch of rain fell within 14 days of soil-applied herbicide applications. Grass control measurements were taken about 120 days after application (DAA). Five trials containing Keystone herbicide each scored an 8 on the 1-to-10 scale, whereas Lumax herbicide scored a 6 and Lexar recorded a 5.



Southern Illinois University evaluated giant foxtail, giant ragweed and waterhemp control at 74 DAA with programs of Keystone® + Hornet herbicides, Lexar, and Lumax + atrazine. All products received a 99 percent control rating for waterhemp control. But for giant foxtail control, Keystone + Hornet WDG gave 94 percent control versus 58 percent for Lumax + atrazine and 68 percent for Lexar. On giant ragweed, Keystone + Hornet had a 92 percent control rating versus 38 percent and 73 percent control from Lumax + atrazine and Lexar, respectively.


At its Urbana location, the University of Illinois looked at giant foxtail control 42 DAA. In this trial, Surpass provided 90 percent control of giant foxtail versus Dual II Magnum herbicide at 50 percent, Stalwart and Define herbicides at 42 percent and Outlook herbicide at 74 percent. For waterhemp control, Dual II Magnum herbicide offered 50 percent control with Stalwart and Define herbicides following behind at 46 percent control and 27 percent control, respectively. In the leader position with 94 percent control, Surpass outcompeted Outlook herbicide with 83 percent control. Leading the pack for lambsquarters control was Surpass with 94 percent control followed by Outlook herbicide with 87 percent control. Dual II Magnum, Stalwart and Define herbicides provided control at 47 percent, 42 percent and 42 percent, respectively.


Giant foxtail control ratings from a Western Illinois trial compared Keystone + Hornet WDG with Lumax and Lexar 52 DAA. In this trial, Keystone + Hornet® WDG herbicides scored 98 percent control, while Lumax and Lexar had 88 percent and 84 percent control, respectively.


A University of Nebraska trial at Clay Center examined control of giant foxtail, yellow foxtail and lambsquarters 70 DAA, comparing Keystone® + Hornet WDG herbicides with Lexar. On lambsquarters, both one-pass, soil-applied options provided 100 percent control. But the difference was in grass control with Keystone + Hornet WDG yielding 95 percent control for giant foxtail versus 89 percent for Lexar. On yellow foxtail, Keystone + Hornet had 94 percent control versus 88 percent for Lexar.


A performance evaluation of Keystone versus Bicep II Magnum herbicide for giant foxtail, common waterhemp and lambsquarters control resulted in Keystone having the upper hand against all three weeds 44 DAA. Control with Keystone® herbicide was 98 percent for giant foxtail and lambsquarters and 96 percent for common waterhemp versus control with Bicep II Magnum at 93 percent for giant foxtail, 71 percent for common waterhemp and 87 percent for lambsquarters.


An evaluation of a Purdue University trial 60 DAA showed an application of Keystone herbicide by itself with 98 percent control of giant foxtail versus 93 percent control provided by Lexar herbicide.


Keystone, Keystone LA, Surpass, FulTime, TopNotch, Bicep, Harness, Lexar and Lumax are Restricted Use Pesticides. Keystone, Keystone LA, Surpass, FulTime and TopNotch are not available for sale, distribution or use in the state of New York. Hornet WDG is not available for sale, distribution or use in Nassau and Suffolk counties in the state of New York. Always read and follow label directions.