USDA to Tackle 2,4-D-Resistant Engineered Crops Without Needed Regulations

May 13, 2013 | 1:04 pm
Doug Gurian-Sherman
Former contributor

It is encouraging that USDA will produce an Environmental Impact Statement (EIS) for crops resistant to 2,4-D or dicamba. These crops, through the herbicides they are designed to use, have potential to cause substantial environmental and human harm, especially due to drift and volatility. Weed scientists have projected dramatically increased use of these herbicides, and herbicides in general, if these crops are approved.

2,4-D injury of a grape leaf. Photo by Ontario Agriculture Ministry.

2,4-D injury of a grape leaf. Photo by Ontario Agriculture Ministry.

Dicamba and 2,4-D herbicides have been known to travel considerable distances from the fields where they are applied, harming fruit, vegetable and other crops, and natural areas that provide pollinators and other beneficial organisms for crops. This is because they not only drift beyond crop fields when they are sprayed, they also volatilize from crops after being applied. Broadleaf crops like grapes and cotton, as well as many others, are extremely sensitive to even low concentrations of these herbicides. In fact, they have been considered to be the most destructive herbicides of neighboring vegetation.

While the pesticide companies claim that new formulations of these herbicides will greatly reduce volatilization, that remains to be seen, because public data supporting this assertion have been scarce. And in any case, some improvement in reducing volatilization may be offset by greatly increased use and new use patterns. In particular, the herbicide-resistant corn and soybeans will allow spraying directly on the growing crops, later in the season, when other crops and wild vegetation have leafed out and are more vulnerable. Previously, most uses of these herbicides have been for pre-emergence (pre crop germination) or post crop harvest.

There is also considerable epidemiology linking these herbicides to certain cancers in farmers and farmworkers. While not conclusive, it does suggest caution. In general, pesticide laws are not as protective of farmers and farmworkers exposed through work as for consumers exposed via residues on food.

In addition, weed scientists predict that the widespread use of these crops will simply speed up the development of more resistant weeds, leading to even more herbicide use. They are especially concerned about the ongoing development of weeds resistant to multiple herbicides, which will further limit farmer options.

The Walking Dead—USDA Regulation of GE Crops is Barely Breathing

It will be important to monitor how thoroughly the USDA does its job. In the past, it has neglected important considerations of harm to growers from contamination by engineered genes or the development of resistant weeds. That was the reason for previous lawsuits that USDA usually lost.

Also important will be how USDA handles the requirement under the National Environmental Policy Act (NEPA) to seriously consider alternatives to approving the engineered crops without restriction. In the past, USDA has not adequately fulfilled this requirement. It should fully consider the best alternatives to the main reason for these crops, the epidemic of glyphosate-resistant weeds.

That should include practices that are known to work well, and to be profitable and highly productive, in particular, crop rotation, judicious tillage (conservation tillage), cover crops, and for non-organic systems, minimal use of various herbicides. Substantial research is accumulating that shows that this approach is viable, and much better for the environment and workers.

Another huge problem, confirmed in its press release, is that USDA is using its regulatory authority under the Plant Protection Act (PPA) only to determine whether 2,4-D- or dicamba-resistant crops are plant pests. The PPA will ultimately determine whether USDA decides that these crops have unacceptable risks. That is because NEPA is a procedural, rather than proscriptive, law. Even if the EIS says that there are risks, it cannot prevent approval. And plant pests, as the term suggests, are usually pathogens, or parasitic plants. So it is unlikely that USDA will find that these herbicide-resistant crops are plant pests, even if they can do considerable harm–they have yet to do so for any GE plant.

The dependence on plant pest properties as a a definition of risk  is also vulnerable to newer ways to make engineered crops. USDA has used the biologically unsupportable fiction that engineered crops may be plant pests simply because a pathogen (Agrobacterium) has been used to deliver the genes into the plant, or that the driver of engineered gene function, called a promoter, came from a plant pathogenic virus. But it is easy to avoid these in many engineered crops now. USDA has affirmed that it would not have jurisdiction to regulate many GE crops if they do not fit these artificial criteria. It did so last year for engineered Kentucky Bluegrass. This does not pertain to 2,4-D or dicamba, which are in the regulatory hopper now, but that could change in the future.

The shame of it is that USDA also has authority under the PPA to determine whether a GE crop is a noxious weed. The statutory definition of a noxious weed under the PPA is quite broad, and gives USDA much greater purview for determining risk than under the plant pest provisions. Despite passage in 2000, USDA has yet to finalize its regulations under the PPA that would include use of its noxious weed authority.

Previous attempts to write regulations, never finalized, inappropriately narrowed the statutory definition of noxious weeds to such an extent that it could have allowed large amounts of harm to the environment, farmers and crops. Fortunately, the Obama administration has not finalized these harmful regulations.

But the lack of appropriate regulations that include a reasonable noxious weed authority greatly limits the types of real environmental impact that USDA will consider, and leaves USDA to regulate these crops with one hand tied behind its back.

One reason that USDA is performing an EIS on these crops is probably the strong public response to earlier actions. Over 400,000 comments on these crops were submitted by the public. Continuing public pressure, including pressure from scientists during the 60-day comment periods for the EIS, will be important for establishing a public record that pushes USDA to do the right thing. We should also demand that USDA develop regulations protective of agriculture and the environment under the PPA. Failure to do so is a dereliction of its responsibility to protect the public and the environment.