University of Georgia Extension weed specialist Stanley Culpepper provides a few thoughts on recent court actions surrounding the registration of three low-volatility dicamba products paired with Xtend crops.
Details of the order
The Environmental Protection Agency’s order addresses sale, distribution, and use of existing stocks of the three affected dicamba products – XtendiMax with vapor grip technology, Engenia, and FeXapan.
Distribution or sale by any person is generally prohibited except for ensuring proper disposal or return to the registrant.
Growers and commercial applicators may use existing stocks that were in their possession on June 3, 2020, the effective date of the court decision. Such use must be consistent with the product’s previously approved label, and may not continue after July 31, 2020.”
Read the full cancellation order on the EPA’s website.
Weed control thoughts
Use only labeled products and follow all labeled directions and restrictions):
Scenario One: Large pigweed with enough in-crop dicamba for two applications: Spray labeled Roundup + dicamba immediately, wait seven to 10 days and then make a second application; 12 days later run the layby rig with either
1) Direx + MSMA + Crop Oil if grasses are not up or
2) Roundup + Direx if grasses are up (add Envoke with layby if morningglory or nutsedge is a problem).
Scenario Two: Large pigweed with enough in-crop dicamba for one application: Spray labeled Roundup + dicamba immediately, wait seven to 10 days and then make a Liberty tank mix application; 12 days later run the layby rig with either
1) Direx + MSMA + Crop Oil if grasses are not up or
2) Roundup + Direx if grasses are up (add Envoke with layby if morningglory or nutsedge is a problem).
Scenario Three: Large pigweed with no dicamba available. Sequential Liberty applications will be best approach although less effective than either dicamba system above. We were able to obtain a new state label for Liberty shortening intervals between sequential applications which will improve control (sending information in blog tomorrow).
Other thoughts
• Tavium registration was not revoked and therefore the herbicide is not impacted as of now.
• The Enlist program of herbicides are following a similar path to that of Engenia, Fexapan, and XtendiMax in the court system. No one can predict the future.
• In Georgia, we have all worked so hard to steward every pesticide and we should collectively be proud! However, this is a wakeup call in several ways.
First, we must work together even harder generating sound science to preempt this type of situation in the future.
Second, for those few growers who have down played the importance of using all pesticides wisely, what a wakeup call!!!!
Dr. Stanley Culpepper is a University of Georgia Extension weed scientist. He may be reached at stanley@uga.edu.