Use of dicamba on dicamba-resistant soybean

October 28, 2020 7:58 AM
Blog Post

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 an approved volatility-reduction agent.
  • There are slight differences in wording of the cutoff date restrictions among the three registered products:
    Xtendimax w/VGT:  Apply before June 30 or up to R1 stage, whichever comes first; 
    Engenia:  Apply before June 30;
    Tavium w/VGT: Apply before June 30 or up to the V4 stage, whichever comes first.
  • Always maintain a 240-ft buffer between last treated row and downwind field edge, increased from the previous 110 ft buffer. Roads, mowed grass and tolerant crops (e.g. corn, Xtend soybean, etc.) can be included in the buffer. The previous Xtendimax 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;
  • A 310 ft downwind buffer and 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).  Labels direct users to EPA website that provides up-to-date info on endangered species.

This list isn't comprehensive, just a quick summary of the labels. 

Bayer Xtendimax w/VGT label
BASF  Engenia

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Bob Hartzler Professor of Agronomy

Dr. Bob Hartzler is a professor of agronomy and an extension weed specialist. He conducts research on weed biology and how it impacts the efficacy of weed management programs in corn and soybean. Dr. Hartzler also teaches undergraduate classes in weed science and weed identificatio...