Dicamba Approval — Quick Briefing On Application Requirements, Restrictions

Rogator herbicide application. Photo: Debra L Ferguson

Rogator herbicide application. Photo: Debra L Ferguson

Most people are aware that EPA approved new labels for the dicamba products used on dicamba-resistant crops.  The following describes major changes in the labels and important restictions.  The labels only describe use on the dicamba-resistant crops, therefore eliminating some of the confusion on earlier labels.

Major changes to dicamba use on DR soybean

  • Must use volatility-reduction agent;
  • Apply before June 30 or up to R1 stage, whichever comes first;
  • Always maintain a 240-ft buffer between last treated row and downwind field edge (roads, mowed grass, tolerant crops can be included in the buffer). The previous label required a 110 ft buffer at 22 oz and a 220 ft buffer at 44 oz.  The 44 oz rate has been eliminated from the label.

General restrictions

  • Apply only one hour after sunrise through two hours before sunset;
  • Apply when wind speed at boom height is between 3 and 10 MPH;
  • Do not apply during temperature inversions;
  • Do not apply product if sensitive crops or certain plants are in an adjacent downwind field;
  • Do not apply if rain is expected in next 48 hours that may result in runoff;
  • Maximum boom height of 24”, maximum ground speed of 15 MPH;
  • Dicamba specific training still required;
  • 57 ft omni-directional buffer required in counties with endangered species (In Iowa, Hardin County and several counties in NE IA are affected by this).

This list isn’t comprehensive, just a quick summary of the label. I assume other products will have similar restrictions. 

Source URL: https://crops.extension.iastate.edu/blog/bob-hartzler/use-dicamba-dicamba-resistant-soybean