Arkansas MAV CDN Hosts Dicamba Symptomology Webinar

The Arkansas MAV Conservation Delivery Network (CDN) hosted a webinar in spring 2019 for its members and other interested partners. The Webinar was led by University of Arkansas's Dr. Ford Baldwin (Weed Scientist, Practical Weed Consultants, LLC) and was intended to inform biologists and conservation professionals about the status of Dicamba in Arkansas and its symptomology and to also share important information about the potential damaging effects this herbicide could have on protected lands.

dicamba damage to an oak tree

dicamba damage to an oak tree

The webinar focused on concerns over changes by the Arkansas Agriculture Department's, State Plant Board, relating to the use of Dicamba. Dicamba is a broad-spectrum herbicide that has been primarily used on agricultural fields in the cool season as a burndown to control broadleaf weeds. In 2017, Arkansas banned the sale and use of Dicamba due to crop damage complaints stemming from aerial drift and the volatility of the herbicide.  However, recent state rulemaking has approved the widespread use of this herbicide in Arkansas on GMO Dicamba-resistant soybeans and cotton through May 25.  

Research demonstrates that Dicamba is extremely volatile; in warm weather it will vaporize from treated fields and spread to neighboring crops and surrounding areas in all directions, sometimes miles, especially during temperature inversions. Its volatility also increases with increasing temperature.  The increased volatility during warmer weather, along with the newly extended application window, means Dicamba could begin damaging sensitive crops and native plants far beyond where it is being applied. In areas of intensive use of these Dicamba tolerant GMO crops, there could be enough build-up in the atmosphere to damage plants on protected lands such as state natural areas, WMA’s, NWR’s, WRP/E, and other important conservation areas. More specifically, it’s believed Dicamba may have significant negative impacts on bottomland hardwoods, pollinator plant species, and wetland or moist-soil plant species.  
View the presentation and listen to an audio recording of the full webinar

JV Elliott