Low Volatility Dicamba and Seed

There was a flurry of activity in the herbicide world early last spring. As a seed guy it did not attract my attention at the time. Monsanto introduced the “Roundup Ready Xtend Crop System.”  The herbicide component of the system was Roundup XtendTM , a combination of glyphosate and dicamba.  The first genetics associated with the system will be soybean varieties with stacked herbicide tolerances to glyphosate and dicamba, branded Roundup Ready 2 Xtend.  Both the herbicide and trait components will require regulatory approval before they can be used. Monsanto hopes to have both in place for use in 2014. The herbicide is to be a low volatility version of dicamba. 1

At the same time, BASF announced  EngeniaTM Herbicide. Engenia is also a low volatility dicamba product. 2 BASF is timing the introduction of Engenia herbicide with the introduction of dicamba tolerant soybeans.  BASF is the largest seller of dicamba in the US, with its Banvel brand and variants. Banvel was introduced in the 1960s. The patents have long since expired.  There are many generic versions available.

The timing of the announcements was not an accident. Monsanto and BASF have been working together on the next generation of dicamba products since 2009. 3

Since BASF and Monsanto have agreed to cross license dicamba herbicide technology, one might think that they would be developing the same formulation.  There is a difference in the reported level of reduction in dicamba volatility which puts identical formulations in doubt.  Monsanto has announced that their formulation reduces volatility by 90%.  The estimate is in this video about their low-volatility formulation.  BASF has announced that the Engenia, when compared with Banvel and Clarity, offers a 40% reduction in volatility. BASF Clarity is a different salt of dicamba than the one that is used in Banvel.  Clarity uses diglycolame and Banvel uses Ddimethylamine. Engenia will use BAPMA, N, N-Bis-(aminopropyl) methylamine. BAPMA “is a tridentate amine, that provides strong and effective binding of dicamba spray residues, thus suppressing potential volatilization of the herbicide.” 4 Monsanto may be using this compound with additional adjuvants to achieve the lower volatility level, but I speculate.  For example, Monsanto has a patent on a system which uses a polybasic polymer to further bind the dicamba salt and reduce volatility.  The description offered in the patent is the combination of dicamba or other auxin herbicide “and a polybasic polymer or mixture of polybasic polymers, wherein the formulation is an aqueous solution. The polymer has a molecular weight of from 600 to 3,000,000 Daltons and has a nitrogen content of from 13 to 50 percent by weight.” 5 This polymer might be available to BASF under the cross licensing agreement, but they might have other reasons to choose not to use it in Engenia.

All of this effort to reduce the volatility of dicamba does not get a lot of credit in the radical environmental movement.  The dangers of increased damage from drift get a lot of coverage in resistance to the US government approvals of transgenic traits for 2,4-D and dicamba resistance.  Last May I did 2 posts on the resistance to the approval of transgenic 2,4-D resistance: 2,4-D Tolerance: Part 1, Health and Environmental Impact, and 2,4-D Tolerance: Part 2, Is There A Critical Juncture in Weed Management? Many of the points made with respect to the environmental impact of 2,4-D tolerance apply to dicamba tolerance.

There is some validity to the concerns for additional drift damage with expansion of usage.  Damage from spay drift is more common than damage associated with vaporization of the herbicide. Changing the formulation will not prevent droplet movement.  Prevention of damage from spray drift can only be addressed through improving the technology, habits, knowledge and skills of spray applicators. These things are, in part, beyond the reach of herbicide and trait suppliers, but they can make a contribution.  For example, BASF is “partnering with Wolf Consulting & Research to launch the On Target Application Academy, a one-of-a-kind, hands-on series of education training programs for growers. 6

The availability of the improved formulations will not completely determine the choice of herbicides which get applied.  In some cases generic dicamba will get used with generic roundup and applied to Roundup Ready 2 Xtend beans.  But we as a society did not ban steam locomotives in the 1800s because sparks from steam locomotives could cause crop fires.  Nor did we as a society make locomotive makers responsible for fires caused the steam locomotives operated by the Union Pacific Railroad as it passed through the wheat fields of Nebraska.  As Ronald Coase pointed out it, makes sense in regulation to make the party which will have the lowest transaction costs in solving the problem responsible for damage.  In this case the people who can best prevent volatilization and drift problems are the sprayer operators.  It seems reasonable to assign responsibility for damage to them.

The challenge is to keep the focus on solving the weed problem.

dicamba resistance systems delivered in seed address dicamba resistant weeds

Image from NC State University, Perspectives Online, Cotton versus Monster Weed, Nancy Hampton

Where the herbicide suppliers make a contribution by making a safer product or contributing to training and the spread of good operator practice, they deserve the collective appreciation of those involved in the agriculture using their products. They cannot be held responsible for all the new problems associated with new products, especially when others get a big share of the benefits from the use of the new products. This is not a popular position with the new agrarians and others who would like to make the choice of society’s technology a collective moral choice to be made before the technology is approved.

The commercial development of new herbicide resistance involves a certain amount of coordination between the herbicide makers and the trait developers in the seed business.  Here is an example of that sort of cooperation.

Paul Christensen

Christensen Consulting

Seed Notes:


1 Monsanto’s New Roundup Ready Xtend Crop System, Monsanto news release, March 1, 2012

2 BASF Outlines Strategies To Manage Resistant Weeds, BASF news release, March 2, 2012

4 ADVANCEMENTS IN DICAMBA FORMULATION. W. Xu1, T. M. Cannan2, C. W. Finch2, G. Schnabel3, M. Bratz*3, S. J. Bowe1, C. L. Brommer4; 1BASF Corporation, Research Triangle Park, NC, 2BASF Corporation, RTP, NC, 3BASF SE, Limburgerhof, Germany, 4BASF, Raleigh, NC (329). Abstract.


6 6 BASF Outlines Strategies To Manage Resistant Weeds, BASF news release, March 2, 2012

Seed Key Words:

Seed, Monsanto, BASF, seed business, science, business, herbicide, weed, resistance, dicamba, volatility.


About Paul Christensen

I am retired Coordinator of the Seed Technology and Business program at the Iowa State University Seed Science Center and Staff member of BIGMAP, the Biosafety Institute for Genetically Modified Agricultural Products. I have also worked for Monsanto, DEKALB Genetics, and Funk Seeds International, which is now part of Syngenta, and worked for USAID in Africa. Much of my technical activity has been associated with product testing and development. As a University Faculty member, I was exposed to many forms of opposition to agricultural biotechnology and the commercial seed industry, and I think that I have developed a unique understanding of some of the philosophical opposition to modern plant technology. I have a well-developed understanding of the kinds of arguments used for and against seed and biotechnology regulation and policy. I have focused on corn, sorghum and sunflower.
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