Dicamba Part I

Barber, 2017

Tom Barber, “Dicamba Drift and Potential Effects on Soybean Yield,” AGWatch Network, July 7, 2016.


Tom Barber, an Extension Weed Scientist at the University of Arkansas, posts a chilling overview of what he has observed in soybean fields in several parts of the state. His piece “Dicamba Drift and Potential Effects on Soybean Yield” contains an ominous warning – “We have observed a 10% [soybean] yield loss from dicamba at rates as low as 1/1024X of the labeled rate” – a very low level of drift and/or movement following volatilization.  Barber also warns that low rates of dicamba drift/movement onto soybeans, especially later in the crop’s growth cycle (i.e. R3-R5) can result in carryover of dicamba in the seed…triggering problems if the soybeans are used for seed in the next year and increasing dietary exposure levels.  FULL TEXT

BASF, 1985

BASF, Marksman Herbicide Label, September 9, 1985, EPA Registration Number: 876-451.


Early label for Marksman herbicide with dicamba plus atrazine.  FULL TEXT

BASF, 1992

BASF, Clarity Herbicide Label, July 23, 1992, EPA Registration Number: 55947-46.


Early label for Clarity Herbicide containing the diglycolamine (DGA) form of dicamba.  FULL TEXT

BASF, 1999

BASF, Distinct Herbicide Label, October 25, 1999, EPA Registration Number: 7969-150.


First label for Distinct herbicide, containing sodium dicamba plus diflufenzopyr (DFFP).  FULL TEXT

BASF, 2007

BASF, Status Herbicide Label, August 24, 2007, EPA Registration Number: 7969-242.


Early herbicide label for Status herbicide, containing sodium dicambaplus DFFP and safener.


BASF, 2016a

BASF, Engenia Herbicide Label, December 20, 2016, EPA Registration Number: 7969-345.


EPA label for Engenia Herbicide for dicamba-resistant crops. FULL TEXT

Behrens et al., 2007

Mark Behrens, Nedim Mutlu, Sarbani Chakraborty, Razvan Dumitru, Wen Zhi Jiang, “Dicamba Resistance: Enlarging and Preserving Biotechnology-Based Weed Management Strategies,” Science, 316, 2007, DOI: 10.1126/science.1141596.


Abstract: The advent of biotechnology-derived, herbicide-resistant crops has revolutionized farming practices in many countries. Facile, highly effective, environmentally sound, and profitable weed control methods have been rapidly adopted by crop producers who value the benefits associated with biotechnology-derived weed management traits. But a rapid rise in the populations of several troublesome weeds that are tolerant or resistant to herbicides currently used in conjunction with herbicide-resistant crops may signify that the useful lifetime of these economically important weed management traits will be cut short. We describe the development of soybean and other broadleaf plant species resistant to dicamba, a widely used, inexpensive, and environmentally safe herbicide. The dicamba resistance technology will augment current herbicide resistance technologies and extend their effective lifetime. Attributes of both nuclear- and chloroplast-encoded dicamba resistance genes that affect the potency and expected durability of the herbicide resistance trait are  examined.  FULL TEXT

DuPont, 2015

DuPont, FeXapan Herbicide Label, July 23, 2015, EPA Registration Number 352-913.


First label for BASF FeXapan Herbicide containing DGA dicamba and inert ingredients intended to reduce volatility and drift.  FULL TEXT

EPA, 2006

Environmental Protection Agency, “Reregistration Eligibility Decision for Dicamba and Associated Salts,” June 8, 2006.


Re-registration documentation for dicamba, including health and environmental assessments. FULL TEXT

Gillam, 2015

Carey Gillam, “Monsanto to invest more than $1bln in dicamba herbicide production,” Reuters, June 24, 2015.


Reports on Monsanto plans to invest heavily in dicamba production in preparation for the launch of dicamba-resistant crops.  A major plant expansion underway in Luling, Louisiana to meet rising demand for dicamba and Monsanto tells Reuters it sees “a 200 million acre ‘practical fit’ for its Roundup Ready Xtend system for soybeans and cotton in the Americas.” FULL TEXT